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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club, and in particular, to an improved head thereof.
2. Description of the Related Arts
In general, it is desirable to transmit the kinematic energy of a club head to a golf ball at the moment of impact, as effectively as possible, in order to increase the distance of flight of the ball. However, since both the ball and the club head are elastic, especially in a wide sense for the latter, elastic damped oscillation takes place on a club face and a ball surface, in accordance with eigentones thereof. Accordingly, if the eigentones of the face of the club head is lower than that of the ball, the elastic deformation of the ball is restored earlier than the restoration of the elastic deformation of the face of the club head which takes place at the moment of impact, so that the ball undesirably separates too early from the face of the club head. This results in an incomplete transmission of the restoration energy of the face of the club head, which elastically deforms at the moment of impact, to the ball, thus resulting in a loss of an initial velocity of the ball.
Japanese Unexamined Patent Publication (Kokai) No. 60-139267 discloses a golf club head having thereon a face insert having an eigentones substantially identical to that of the ball. However, in the club head disclosed in the publication, the eigentones of the face insert is made identical to that at the ball, an elastic damped oscillation of the face insert takes place under the influence of the eigentones of the remaining portion of the club head which usually has an eigentones frequency lower than that of the face insert.
Generally speaking, the lighter the wieght of a material, the larger the eigentones thereof, and accordingly, it is deirable to concentrically locate the weight portion of the head, as close as possible to a rear portion of the head, so that the face of the head is lighter, in order to minimize the possible influence of the eigentones of the head portion other than the face insert given to the elastic damped oscillation frequency of the face of the head.
However, in the prior art, since the head portion other than the face insert is made of a same material, it is not possible to satisfactorily concentrate the weight distribution of the head in the vicinity of the rear portion thereof.
SUMMARY OF THE INVENTION
The primary object of the present invention is, therefore, to provide a golf club head having a head body which has a sole and a face, and which is made of a light material having a high specific elasticity, said head body being provided, on its rear portion, with a weight body having a specific gravity heavier than that of the head body, said head body being provided therein with a cavity. The specific elasticity referred to herein is a ratio of modulus of elasticity (Young's modulus) relative to the density of the material.
With the above arrangement, the weight portion of the head is concentrically located at the rear portion thereof and the face of the head is lighter, since the weight body is heavier than the head body, which is made of a light material having a high specific elasticity, and is located at the rear portion of the head body, and because the cavity is formed in the head body. As a result of this concentric distribution of the weight, the face of the head has an increased eigentones, so that the elastic damped oscillation frequency of the face of the head is substantially identical to a standard elastic damped oscillation frequency of golf balls at the moment of impact. This results in a sufficient transmission of the restoration energy of the face of the head, which elastically deforms, to a golf ball, thus resulting in an increase in the distance of flight of the ball.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described below in detail with reference to the accompanying drawings, in which:
FIG. 1 is a perspective rear view of a club head of an iron club, according to an embodiment of the present invention;
FIG. 2 is an exploded perspective view of a head body and a weight body shown in FIG. 1;
FIG. 3 is a sectional view taken along the line III--III in FIG. 1;
FIG. 4 is a perspective view of a club head of an iron club according to a second embodiment of the present invention;
FIG. 5 is an enlarged sectional view of a hollow spherical body used in a club head shown in FIG. 4;
FIG. 6 is a plan view of a club head of a wood club, according to a third embodiment of the present invention; and,
FIG. 7 is a sectional view taken along the line VII--VII shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 1 to 3, which show a first embodiment of the present invention applied to an iron club, a club head 12, which is integrally connected to a lower end of a club shaft 11, has a head body 13 having a face 13a and a sole 13b. The head body 13 is made of a light material having a high specific elasticity, such as fiber reinforced plastics or a fiber reinforced metal or ceramics.
As can be seen from FIGS. 2 and 3, the head body 13 is provided therein with a recess 14 which opens toward the rear portion of the head body 13. The recess 14 has, at the open end edge thereof, a peripheral spot facing 15. A plate like weight body 16, which is made of a metal having a larger specific gravity than the head body 13, such as stainless steel, titanium, or brass, is located in and on the spot facing 15 and secured to the head body 13 by means of an adhesive or the like.
The weight body 16 covers the recess 14 to define a cavity 10 in the head body 13.
With the construction shown in FIGS. 1 to 3, since the weight body 16, which is heavier than the head body 13 of a light material having a high specific elasticity, is provided on the rear portion of the head body 13, and since the cavity 10 is formed in the head body 13, the weight is concentrically distributed at the rear portion of the club head, and the face side of the head is lighter. This enables the face of the head to have an increased eigentones so as to substantially conform the elastic damped oscillation frequency of the face of the club head to a standard elastic damped oscillation frequency of the golf balls at the moment of impact. As a result, the restoration energy of the face of the club head, which elastically deforms at the moment of impact, can be sufficiently transmitted to the golf ball, thus resulting in an increase in the distance of flight of the golf balls.
Due to the presence of the cavity 10 in the head body 13, the face 13a of the head body can easily, elastically, and largely deform at the moment of impact. This results in an increase in the time of contact between the golf ball and the face of the head, thus resulting in an improved control of the direction of flight of the golf ball.
In addition to the foregoing, since the depth of the center of gravity of the club head 12 from the face 13a thereof becomes large, due to the presence of the weight body 16 at the rear portion of the head body, a moment of inertia about the center of gravity of the head 12 is increased. This also contributes to an improved control of the direction of flight of a golf ball. Furthermore, since the weight body 16 is located in the rear of the face 13a of the head 12, a shock wave applied to the face 13a at the moment of impact is effectively reflected by the weight body 16 and acts on a golf ball through the face 13a, so that the initial speed of the flight of a golf ball can be increased.
FIGS. 4 and 5 show a second embodiment of the present invention, applied to a club head of an iron club. In FIGS. 4 and 5, the components corresponding to those in the first embodiment illustrated in FIGS. 1 to 3 are designated by the same numerals.
In the second embodiment illustrated in FIGS. 4 and 5, the head body 13, which is made of a light material of high specific elasticity, has a base member 17 and a large number of small hollow spherical bodies 18, dispersed therein. Note, the hollow bodies can be any shape other than spherical. The cavities of the spherical bodies 18 correspond to the cavity 10 in the first embodiment shown in FIGS. 1 to 3. The base member 17 is made of, for example, fiber reinforced plastics, fiber reinforced metal, or ceramics, or the like. The plate like weight body 16, which has a larger specific gravity than the head body 13, can be made of a same material as that of the weight body in the first embodiment. The spherical bodies 18 are preferably made of commercially available hollow glass balls having outer diameters of about 70 μm.
These glass balls have an apparent specific gravity of 0.15˜0.38 g/cm 3 , which is very small, and can be dispersed in the base member 17 with a high distribution density, contributing to a decrease of weight of the head body 13.
In the second embodiment shown in FIGS. 4 and 5, since the weight body 16, which has a heavier specific gravity than the head body 13 which is made of a light material having a high specific elasticity, is provided at the rear portion of the head body 13, and since the cavity consisting of the hollow portions of the small spherical bodies 18 is provided in the head body 13, the same effects as those in the first embodiment can be expected.
FIGS. 6 and 7 show a third embodiment of the present invention applied to a club head of a wood club. In the third embodiment illustrated in FIGS. 6 and 7, the components of the third embodiment corresponding to those in the first and second embodiments are designated by the same numerals.
In the third embodiment, the head body 13, which is made of a light material having a high specific elasticity, has a base member 19 having a hollow portion 19a filled with foamed resin material 20.
The cavity in the third embodiment is formed by foamed inside portions of the foamed resin filler 20. In the third embodiment, the hollow portion 19a of the base member 19 opens into the face 13a of the head body 13, though not limited thereto, and accordingly, a golf ball can be hit by the face 13a formed by the foamed resin filler 20. The base member 19 can be made of, for example, fiber reinforced plastics, fiber reinforced metal, or ceramics or the like. The plate-like weight body 16, having a specific gravity larger than that of the head body 13, can be made of materials similar to those in the previous embodiments. As the foamed resin filler 20, urethane foamed resin, or epoxy foamed resin, or the like can be used. The eigentones of the face of the head 13a can be optionally controlled by changing the foaming conditions of the foamed resin of which the foamed resin filler is made.
In the third embodiment, since the weight body 16, which has a heavier specific gravity than the head body 13 which is made of a light material having a high specific elasticity, is provided at the rear portion of the head body, and since the cavity is provided in the head body 13, the same effects as those of the previous embodiments can be expected.
The present invention can be modified or varied by those skilled in the field of the invention without deviating from the scope of protection of the invention.
For example, it is also possible to repalce the hollow portion 19a with a closed hollow portion which is sealed by the base member 19, so that the face of the head is formed by the base member rather than the foamed resin filler 20, which is completely enclosed in the closed hollow portion. In this alternative, golf balls are hit by the club face made of the base member in place of the foamed resin filler.
As can be seen from the foregoing description, according to the present invention, since the weight body, which has a heavier specific gravity than the head body which is made of a light material of a high specific elasticity, is provided at the rear portion of the club head body, and since the cavity is provided in the head body, the weight portion can be concentrically located at the rear portion of the head and the head club face can be made lighter. Therefore, it is possible to increase the eigentone of the club face at the moment of impact, in order to make the elastic damped oscillation frequency of the club face substantially coincident with a standard or specific elastic damped oscillation frequency of commonly used or specific golf balls. This enables the restoration energy of the club face of the club head, which elastically deforms at the moment of impact, to be effectively transmitted to a golf ball, resulting in an increase in the distance of flight of the golf ball.
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A club head of a golf club comprises a head body having a face which is made of a material having high specific elasticity and a weight body made of another material having a specific gravity greater than that of the material of the head body and provided at and covering a substantial portion of a rear portion of the head body, the head body being provided therein with a cavity, the total weight of the weight body being heavier than that of the head body.
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BACKGROUND
The invention relates to controlling the ratio of regenerative braking to friction braking in hybrid vehicles. Specifically, fuzzy logic is used to determine the amount of regenerative and friction braking to use based on a variety of sensed parameters.
Hybrid vehicles generally use regenerative braking to decelerate the vehicle and recharge the batteries. However, in certain circumstances (e.g., during a dynamic maneuver such as skid correction) the vehicle uses friction braking because of the greater braking control provided by friction breaking.
SUMMARY
The invention uses fuzzy logic to determine a ratio of regenerative braking to friction breaking for each wheel of a vehicle, enabling greater use of regenerative braking, and, thus, greater recapture of energy from the vehicle.
In one embodiment, the invention provides a controller for controlling braking of a wheel of a vehicle. The controller includes a first connection to a friction brake, a second connection to a motor/generator, a third connection to a plurality of sensors, and a fuzzy logic module. The motor/generator is configured to drive the wheel in a driving mode and to brake the wheel in a regenerative braking mode. Operating parameters of the vehicle are sensed by the plurality of sensors. The fuzzy logic module is configured to determine a stability of the vehicle and the wheel based on data from the plurality of sensors. The fuzzy logic module allocates braking force between the friction brake and the motor/generator operating in the regenerative braking mode based on the stability of the vehicle and the wheel.
In another embodiment the invention provides a method of allocating braking force in a vehicle between a regenerative brake and a friction brake. The method includes receiving a sensed speed of a wheel, a yaw rate of the vehicle, and lateral acceleration of the vehicle, determining an acceleration/deceleration of the wheel, a slip of the wheel, and a jerk of the wheel, performing a first fuzzy operation on the jerk, the slip, the yaw rate, the lateral acceleration, and the acceleration/deceleration of the wheel, the first fuzzy operation returning a value indicative of a stability of the respective wheel parameter, performing a second fuzzy operation on a vehicle speed, the second fuzzy operation returning a value indicative of an impact the vehicle speed has on the stability of the vehicle, determining via a third fuzzy operation an amount of braking power to be applied via regenerative braking versus friction braking, and providing an indication of the amount of braking power to be applied via regenerative braking to a regenerative brake.
In another embodiment the invention provides a vehicle, including a wheel, a wheel speed sensor, a friction brake configured to brake the wheel, a motor/generator configured to drive the wheel in a driving mode and to brake the wheel in a regenerative braking mode, a throttle sensor configured to sense a position of a throttle of the vehicle, a brake pedal sensor configured to sense a position of a brake pedal of the vehicle, a plurality of sensors sensing operating parameters of the vehicle, and a controller coupled to the wheel speed sensor, the friction brake, the motor/generator, the throttle sensor, the brake pedal sensor, and the plurality of sensors. The controller includes a fuzzy logic module configured to determine a stability of the vehicle based on data from the plurality of sensors and to allocate braking force between the friction brake and the motor/generator operating in the regenerative braking mode based on the stability of the vehicle.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a vehicle.
FIG. 2 is a model of a fuzzy logic based system for allocating braking force between regenerative and friction brakes.
FIG. 3 is a fuzzy logic graph for determining a weighting factor based on vehicle speed.
FIG. 4 is a first fuzzy logic graph for determining an output based on an input and a pair of variables.
FIG. 5 is a second fuzzy logic graph for determining an output based on an input and a pair of variables.
DETAILED DESCRIPTION
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
FIG. 1 shows a hybrid vehicle 100 . The vehicle 100 includes a left front wheel 105 , a right front wheel 110 , a left rear wheel 115 , and a right rear wheel 120 . Each of the wheels 105 - 120 has an associated motor/generator 125 - 140 . The wheels are capable of being driven by a combustion engine 145 and/or their electric motors 125 - 140 (which in the embodiment shown are position directly adjacent each wheel). The vehicle 100 also includes a plurality of sensors including wheel speed sensors 150 - 165 (each associated with one of the wheels 105 - 120 ), a steering angle sensor 170 , a lateral acceleration sensor 180 , a longitudinal acceleration sensor 185 , a yaw rate sensor 190 , a throttle position sensor 195 , and a brake pedal position sensor 200 . The sensors 170 - 200 provide indications of the various parameters they sense to an engine control unit (ECU) 205 which includes electronic stability control functionality. In some embodiments, one or more of the sensors are not used. Instead the information that would be provided by the sensor is developed using data from one or more other sensors.
FIG. 2 shows a block diagram of a model 250 of the operation of a system using fuzzy logic to allocate braking control between regenerative braking and friction braking for a wheel of the vehicle 100 . The model 250 can be implemented in hardware, software, or a combination of hardware and software. In addition, modules described below can be implemented in hardware, software, or a combination of hardware and software, and can be integrated or distributed. The wheel speed sensors 150 - 165 , the steering angle sensor 170 , the lateral acceleration sensor 180 , the longitudinal acceleration sensor 185 , the yaw rate sensor 190 , the throttle position sensor 195 , and the brake pedal position sensor 200 provide signals indicative of their respective sensed parameters to the ECU 205 . An electronic stability control (ESC) module 255 of the ECU 205 provides information on the brake pedal and throttle positions to an acceleration/deceleration module 260 . The module 260 determines a desired acceleration/deceleration (e.g., in meters per second squared—m/s2). The module provides the desired acceleration/deceleration to a subtractor 265 . The ESC module 255 also provides an indication of actual acceleration/deceleration 267 (in m/s2) to the subtractor 265 . The actual acceleration/deceleration is obtained from the longitudinal acceleration sensor 185 . In some embodiments, the acceleration/deceleration is determined using data from sensors other than the longitudinal acceleration sensor 185 (e.g., using wheel speed sensors). The subtractor 265 generates an error signal 270 indicative of the difference between the desired acceleration/deceleration and the actual acceleration/deceleration. The error signal 270 is provided to a proportional-integral-derivative (PID) controller 275 . The PID controller 275 is a closed-loop controller which generates a braking signal 280 indicative of an amount of braking force that should be applied based on present and past desired and actual vehicle acceleration/deceleration. The braking signal 280 is indicative of an amount of braking force that should be applied to an individual wheel.
The braking signal 280 is fed to a fuzzy logic controller 285 . The fuzzy logic controller 285 also receives a plurality of signals 290 from the ESC module 255 . The plurality of signals 290 include data on the wheel speed, wheel acceleration/deceleration, wheel jerk, wheel slip, vehicle lateral acceleration, and vehicle yaw rate. Using the plurality of signals 290 , the fuzzy logic controller 285 allocates braking force between regenerative and friction braking. The fuzzy logic controller 285 determines a stability of the vehicle 100 and of the individual wheel, assigning values between zero (i.e., very unstable) and one (very stable). The greater the stability, the more of the braking force that is allocated to regenerative braking. The fuzzy logic controller 285 produces a signal 295 indicative of the force to be applied by regenerative braking, and a signal 300 indicative of the force to be applied by friction braking.
There is a limit to the amount of braking force regenerative braking can provide. This is referred to as the regenerative braking saturation point. The fuzzy logic controller 285 provides the signal 295 to a saturation module 305 . If the braking force to be applied by regenerative braking exceeds a saturation point, the saturation module 305 provides a signal to the regenerative brake to apply its maximum braking force, and also provides a signal to an adder 310 indicative of the amount of braking force that exceeds the saturation point. The adder 310 combines the amount of force that exceeds the saturation point with the amount of friction braking force received from the fuzzy logic controller 285 (signal 300 ), and provides a signal to the friction braking system indicating the combined braking force the friction braking system should provide.
In some embodiments, the ECU 205 and/or other modules include a processor (e.g., a microprocessor, microcontroller, ASIC, DSP, etc.) and memory (e.g., flash, ROM, RAM, EEPROM, etc.; i.e., a non-transitory computer readable medium), which can be internal to the processor, external to the processor, or both.
Operation of the Fuzzy Logic Controller 285
The fuzzy logic controller 285 uses a plurality of process variables and sensed parameters. The list below shows the variables and parameters used by the fuzzy logic controller:
V=vehicle speed (m/s).
ψ=yaw input from the yaw rate sensor 190 in radians per second (rad/s).
γ=fuzzy based weighting factor based on vehicle speed.
λ=wheel slip (%).
V″=wheel jerk (m/s 3 ).
V′=wheel acceleration/deceleration (m/s 2 ).
Ay=lateral acceleration (m/s 2 ) (from the lateral acceleration sensor 180 ).
axF=longitudinal acceleration (m/s 2 ) (from the longitudinal acceleration sensor 185 ).
X 1 is an output of a first fuzzy logic operation based on V′.
X 2 is an output of a second fuzzy logic operation based on V″.
X 3 is an output of a third fuzzy logic operation based on λ.
X 4 is an output of a fourth fuzzy logic operation based on Ay.
X 5 is an output of a fifth fuzzy logic operation based on ψ.
Y 1 , Y 2 , Y 3 are temporary variables.
C 1 and C 2 are parameters that are preset based on the fuzzy logic operation.
RB is the regenerative braking portion of the total braking force.
FB is the friction braking portion of the total braking force.
Each of the fuzzy logic operations returns a value between zero and one inclusive. In some embodiments, γ is determined based on the speed of the vehicle 100 using the chart shown in FIG. 3 . When the vehicle 100 is traveling at less than 5 m/s, γ=1. When the vehicle 100 is traveling at greater than 20 m/s, γ=0.5. When the vehicle 100 is traveling at a speed between 5 and 20 m/s, γ is determined by the equation γ=1−(V−5)/30 as shown in FIG. 3 .
In some embodiments, X1, X2, X4, and X5 are determined using the graph shown in FIG. 4 . X3 is determined using the graph shown in FIG. 5 when the vehicle is accelerating, and using the graph in FIG. 4 when the vehicle is decelerating. In one embodiment, when the vehicle 100 is taking off (accelerating from a stop) or accelerating:
X 1 is determined using input |V′| and parameters C 1 =4.2 m/s 2 and C 2 =6.0 m/s 2 .
X 2 is determined using input |V″| and parameters C 1 =2 m/s 3 and C 2 =20 m/s 3 .
X 3 is determined using input λ and parameters C 1 =f(V) and C 2 =f(V).
X 4 is determined using input |Ay| and parameters C 1 =3.0 m/s 2 and C 2 =9.0 m/s 2 .
X 5 is determined using input |ψ| and parameters C 1 =0.4 rad/s and C 2 =0.7 rad/s.
And, when the vehicle 100 is decelerating:
X 1 is determined using input |V′| and parameters C 1 =8.4 m/s 2 and C 2 =14.0 m/s 2 .
X 2 is determined using input |V″| and parameters C 1 =15 m/s 3 and C 2 =150 m/s 3 .
X 3 is determined using input X and parameters C 1 =0.03 and C 2 =0.07.
X 4 is determined using input |ay| and parameters C 1 =2.0 m/s 2 and C 2 =8.0 m/s 2 .
X 5 is determined using input |ψ| and parameters C 1 =0.3 rad/s and C 2 =0.6 rad/s.
Once X1 through X5 are determined, they are used to solve the following equations:
Y 1 =γ*MIN( X 1 ,X 2 )+(1−γ)*( X 1 +X 2 )/2
Y 2 =γ*MIN( Y 1 ,X 3 )+(1−γ)*( Y 1 +X 3 )/2
Y 3 =γ*MIN( Y 2 ,X 4 )+(1−γ)*( Y 2 +X 4 )/2
Then the portion of braking force to be applied to regenerative braking PR is determined by:
P R =γ*MIN( Y 3 ,X 5 )+(1−γ)*( Y 3 +X 5 )/2
Finally, the actual regenerative braking force BR is determined by multiplying the portion by the output of the PID controller 285 :
B R =P R *PID OUT
And, the actual friction braking force BF is determined by multiplying the portion to be applied to friction braking (1−PR) by the output of the PID controller 285 :
B F =(1 −P R )* PID OUT
Again, any BR that exceeds a predetermined saturation threshold is added to BF. The process is performed for each of the four wheels.
For example, for a situation where the vehicle 100 is traveling at 10 m/s (γ=0.83) and is accelerating at a slow rate (V′<4.2 m/s2), wheel jerk is small (V″<2 m/s3), wheel slip is small, vehicle yaw rate is small (ψ<0.4 rad/s), and vehicle lateral acceleration is small (Ay<3.0 m/s2). In addition, X1 through X5 are all 1.0 (very stable). Solving the equations above results in RB being one. This means that all braking force (up to saturation) is applied via regenerative braking.
As a second example, consider a situation where the vehicle 100 is braking in a turn, and the vehicle 100 is decelerating from 20 m/s (γ=0.5) at a relatively rapid wheel deceleration (V′·12 m/s 2 ), wheel jerk is moderate (V″˜82 m/s3), wheel slip is moderate, vehicle yaw rate is relatively large (Φ˜5.4 rad/s), and vehicle lateral acceleration is large (Ay˜7.7 m/s2), using the fuzzy operations, X1=0.3, X2=0.5, X3=0.6, X4=0.1, X5=0.2, and solving the equations above, yields Y1=0.35, Y2=0.4125, Y3=0.1781, and RB=0.1836. Therefore, FB=0.8164. Because the sensed parameters indicate that the vehicle 100 and the wheel are relatively unstable, 82% of the braking force is applied using friction braking and 18% is applied via regenerative braking. However, this 18% of regenerative braking is greater than prior-art systems, which go to 100% friction braking, and 0% regenerative braking, whenever an unstable condition is encountered.
The variables used above are for example only, and are not intended to be limiting. Variables can be chosen based on actual vehicle testing, and can vary between different vehicles.
Thus, the invention provides, among other things, a fuzzy logic based brake control system. Various features and advantages of the invention are set forth in the following claims.
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A controller for controlling braking of a wheel of a vehicle. The controller includes a first connection to a friction brake, a second connection to a motor/generator, a third connection to a plurality of sensors, and a fuzzy logic module. The motor/generator is configured to drive the wheel in a driving mode and to brake the wheel in a regenerative braking mode. Operating parameters of the vehicle are sensed by the plurality of sensors. The fuzzy logic module is configured to determine a stability of the vehicle and the wheel based on data from the plurality of sensors. The fuzzy logic module allocates braking force between the friction brake and the motor/generator operating in the regenerative braking mode based on the stability of the vehicle and the wheel.
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This is a division of application Ser. No. 09/131,623 filed Aug. 10, 1998 now U.S. Pat. No. 6,096,126.
TECHNICAL FIELD
This invention relates generally to sports field conditioners used for constructing, amending, and top dressing athletic fields and more particularly to a non-swelling, porous calcined clay aggregate having a specific particle size distribution suitable for use thereas.
BACKGROUND ART
Athletic fields such as baseball fields, softball fields, soccer fields and football fields are subject to extraordinary demands. Heavy foot traffic, play during inclement weather and overuse lead to problems in effective field management. Additionally, the poor physical structure of soils (native and imported), improper construction techniques and improper maintenance magnify problems caused by these factors.
The most common problem in baseball and softball field maintenance is providing a skinned infield surface that is playable in all weather conditions. Furthermore, due to budget and manpower constraints, these infields must be easy to maintain. More than 80 percent of all activity during a game takes place in this area.
The majority of infields are constructed using a soil mix comprising sand, silt and clay. The percentages of sand, silt and clay in an infield mix varies across the world based on local soil sources. No standard exists for major league baseball or for softball.
Desirable characteristics for playability include the following: a smooth, level surface for running, sliding and fielding balls; a loose, friable surface having between ¼ inch and ½ inch of loose surface material that provides a cushioned surface for ball hops, running and sliding, and which exhibits relative freedom from skin abrasion due to sliding contact with the surface; a surface that does not become slippery when wet, i.e., one which can absorb light rains and provide surface drainage during heavy rains; a surface that drains well and dries out quickly in wet weather; a surface that does not dry, become hard, and crack during the hot summer months, i.e., a surface capable of retaining minimum moisture levels; a surface that is easy to scarify using a nail drag or other implement that reduces surface compaction.
During the last 30 years, an industry has developed which provides groundskeepers and coaches with materials and tools that help make infields playable. Universities and private industry have invested substantial amounts of money and time in attempting to understand infield maintenance and construction. Recently, governing bodies have been created in an attempt to standardize practices and to provide recommendations to groundskeepers and coaches.
The most common method of improving a skinned infield is to modify and top dress infield soils with amendments that absorb moisture and help the field remain loose and friable. There are several objectives to adding amendments to infields. Some products are more effective than others in meeting these objectives.
Common among the objectives are the following.
1. Mixed into the top 4 to 6 inches of skinned soil, the amendments absorb rain and other moisture from infield soils so that the field does not become muddy during rainy days.
2. Mixed into the top 4 to 6 inches of skinned infield soil, the amendments help prevent compaction by preventing infield soils from binding together.
3. Used as a light surface top dress, they provide a loose, level, smooth playing surface.
4. Used as a surface top dress, the amendments provide a loose surface suitable for diving and sliding into bases.
5. The amendments retain moisture during hot summer months to keep a field from drying out and becoming hard and difficult to maintain, while encouraging drainage.
6. They provide a brown to red color that gives a field a “major league” appearance.
Amendments which have been tried in the past include sand, cat litter, oil and grease absorbents, calcined diatomaceous earth and crushed aggregates including brick, limestone, sandstone, shale, etc. There are several properties that differentiate amendments. They include particle sizes, moisture absorption capability, color, and physical stability.
Sand has not proved to be an acceptable amendment in most cases. Because of its small particle size, at least 80 percent by weight of sand must be present in a soil structure to keep that soil from becoming compacted. Amounts less than 80 percent actually encourage compaction since the sand fills available pore space in the soil. Other properties that make sand less desirable include its negligible water absorption and retention capacity. While soils containing very high sand content generally drain rapidly, there are no pores to retain the residual moisture necessary to obtain optimum playability, especially during hot summer months.
Cat litter was one of the first materials tried by groundskeepers to absorb moisture on infields following a rain. Cat litter is a dried clay containing substantial amounts of sodium and/or magnesium bentonites or other clays which may exhibit massive swelling in the presence of water. Although these products absorb water, the water causes rehydration of the dried clay, which breaks down quickly into a wet clayey mass. It can be used effectively only one time to absorb moisture, and if used often, can produce a surface which is slippery when wet, and which contributes to poor drainage by clogging intergranular drainage passages. Because it breaks down easily, it is not used for top dressing infields to provide a consistent surface.
Oil and grease absorbents are similar to cat litter in that they are manufactured to absorb liquids one time. Oil and grease absorbents have a very wide particle size distribution and also rehydrate into a wet clay.
Materials such as calcined diatomaceous earth, many crushed sandstones, crushed limestone, and similar white or light-colored materials have seen little acceptance as soil amendments for skinned sports fields. None of these materials due to their color, are acceptable as top dressing. In addition, calcined diatomaceous earth is brittle, and rapidly breaks down. Crushed brick and shale have been touted as amendments, but have been found to contribute to cuts and abrasion during sliding. Crushed brick, additionally, does not have the desired porosity. Both crushed brick and shale have been shown to decrease soil drainage.
Ceramic aggregates used as heavy duty oil and grease absorbents offer some of the desirable characteristics for a soil amendment material. However, the color of most of these products is not suited for infields. Moreover, when used as top dressing, these materials have been shown not to perform satisfactorily. A brown to red colored product of the assignee of the present invention has achieved success as a soil amendment for skinned sports fields. However, playing performance and application performance are still in need of improvement.
It would be desirable to provide to the industry a porous amendment which is inexpensive, which promotes rapid drainage while exhibiting considerable water retention, which is of a uniform and acceptable red-brown color, which exhibits playing characteristics which render the amendment suitable not only as a below-surface additive, but for top dressing as well, which is non-swelling, and which is stable, i.e., resisting both physical and chemical break down, and in particular, hydration to fine clayey materials.
SUMMARY OF THE INVENTION
The present invention employs a unique porous calcined clay material having a unique and well defined particle size distribution as a soil amendment or top dress for skinned sports fields. The calcined product is prepared by calcining a smectite clay material, most preferably an iron-containing smectite clay, followed by granulating (crushing), screening, and dedusting. The soil amendment is fast draining yet retains residual moisture, does not cause soil compaction, and provides a surface of superior playability to existing products.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The soil amendments of the present invention are prepared by calcining a smectite clay. While numerous smectite clays are feasible for use herein, those containing significant quantities of montmorillinite, and opal CT (cristobalite, tridymite) are preferred. Other Clays suitable are particularly the smectite clays such as bentonite, montmorillinite (as previously indicated), beidellite, nontronite, hectorite, saponite, attapulgite, and sepiolite. Reference as to these and other clay minerals may be had to I NTRODUCTION T O C ERAMICS , W. D. Kingery, John Wiley & Sons, N.Y. ©1960, particularly pages 15-32, incorporated herein by reference.
A preferred clay is a clay containing between 10 and 50 percent montmorillinite, and 30 and 80 percent opal CT, with varying content of quartz, other clays, minerals, and impurities, as measured by x-ray diffraction. A more preferred clay contains from about 20 to about 35 percent montmorillinite, and about 45 to about 60 percent opal CT.
The use of a raw material comprising 27 percent montmorillinite, 5 percent quartz, and 55 percent opal CT, has been found to be advantageous. During calcining, numerous clay materials are modified into other minerals. In the latter advantageous clay composition, for example, the calcined product contains about 1.4 percent montmorillinite, 27 percent illite, 7 percent quartz, and 42 percent opal CT by x-ray diffraction. The illite may include between 70 and 80 percent silicon dioxide, 5 and 15 percent aluminum oxide, and 2 and 8 percent ferric oxide. Preferably the illite composition is 74 percent silicone dioxide, 11 percent aluminum oxide, and 5 percent ferric oxide.
The nature of the precursor clay is not critical as long as a porous calcined clay product is obtained which is capable of being crushed to the particle density and bulk density limitations described herein, and preferably one which allows for a deep red to brown and relatively uniform color to be obtained. The deep color is believed to be due to iron-containing minerals or organic matter, and thus iron-containing clays are preferred. In addition to the foregoing properties, the calcined granules must not easily rehydrate, and must be stable granules, having a particle stability reflected by less than 15 percent degradation in the ASTM C-88 Sulfate Soundness Test, and preferably less than 12 percent degradation, on average, or less. The granules should preferably also exhibit less than 15% degradation in the Static Degradation test, a common test in the mineral arts. All these properties are easily measured by one of ordinary skill in the art, and thus suitable ceramic precursor materials can easily be selected.
The granules also advantageously have a total porosity of at least 30 percent, preferably at least 50 percent, and more preferably about 75 percent. Of the total porosity, it is preferred that at least 20 percent be capillary porosity, more preferably at least 35 percent, and most preferably about 50 percent, the percentage of capillary porosity expressed as a percentage of the total porosity also expressed as a percentage.
Preferably, suitable precursors contain greater then 1% by weight iron as iron oxide, and enough iron, together with other colored oxides and color-imparting components, to produce a red-brown tone to the granules. The iron may be supplied as a component of the clay mineral, e.g., illite containing 5 weight percent iron oxide; may be supplied by adding pure or impure iron oxide or iron minerals to the ceramic precursor prior to calcining, or may be in the precursor clay in the form of iron-containing organic material, humus, or the like. By the term “iron-containing” is meant that the precursor clay will contain sufficient iron to impart a tone to the calcined granulates which ranges from red to brown or gold-brown, and shades inbetween.
The precursor clays are commonly mined from single deposits and crushed to rather fine particle sizes prior to calcining at temperatures ranging from about 540° C. to about 1100° C. (1000° F. to 2000° F.). The actual calcining temperature will depend upon the particular precursor clay and can be easily determined by one skilled in the art. In general, finer particle sizes than are customarily used for ceramics such as oil absorbent granules are employed, as these smaller particle sizes encourage formation of calcined granules having uniform color. If the calcining temperature for the particular precursor clay is too low, the granules will not pas the Sulfate Soundness test, or may rehydrate upon addition of water. If the temperature is too high, densification may occur and porosity will be lost. The product granules should have a pore size ranging from 0.1 μm to 100 μm, and should have a total porosity of at least 30 percent, preferably at least 50 percent. Porosity may be measured by standard porosimetry methods, or may be measured by water intake by the calcined granules.
During the calcining process, dehydration of the clay minerals occurs, and the mineral particles coalesce, agglomerate, and densify. Crystal grain growth may occur. The calcined product is cooled slowly, then broken up into generally angular granulates. These granulates are not suitable for use in the present invention due to the wide range of particle sizes. Rather, the granulate must be processed by screening or sieving to eliminate most and preferably substantially all particles larger than 2.0 mm; to substantially eliminate most granules having particle sizes of less than 0.85 mm, and in particular to reduce fine particulates having particle sizes less than 0.3 mm. Screening processes are well known, and can be used to provide any desired particle size distribution consonant with the particle sizes delivered to the screening apparatus. When the proper size distribution is obtained, the product may be, and preferably is, pneumatically dedusted to remove very fine particles. In the present invention, the crushing and screening operations are conducted so as to prepare a final, substantially dust free granulate having the following particle size ranges.
TABLE 1
PARTICLE
PERCENTAGE
PREFERRED
TYPICAL
SIZE
RANGE
RANGE
PERCENTAGE
>2.00 mm
≦15.0
≦10.0
8.4
10 MESH
0.85-2.00 mm
≧60.0
≧70.0
81.5
20 × 10 MESH
0.60-0.85 mm
≦17.5
≦10.0
8.5
30 × 20 MESH
<0.60 mm
≦7.0
≦5.0
1.5
50 × 30 MESH
It should be noted that the substantial majority of the particles, preferably 70 wt. % or more, are within the size range 0.85-2.0 mm. The mesh values below the size ranges indicate which mesh screen (left most, or lower value) will retain the particles in the particular size range, and the upper limit (right most mesh value) through which larger granulates will not pass. Thus, the lower limit of the first size range is 2.0 mm which the upper limit of the second size range is 2.0 mm. These values should be interpreted as having produced the size range by use of mesh screens of the stated sizes. Thus, there is no actual overlap between adjacent ranges.
It should be noted that the particle size distribution is not similar to that obtained by standard crushing and screening operations. For example, dried clay oil adsorbants have a very wide particle size distribution. Applicants have surprisingly found that the present inventions' particle size range uniquely satisfies the often conflicting demands of soil amendment particles.
The assignee of the present invention has marketed a porous calcined clay product for 30 years, which is now sold under tradename Turface® MVP. Analysis of typical particle size ranges of this product and the soil amendment of the present invention is presented in Table 2 below:
TABLE 2
SUBJECT INVENTION
SOIL AMENDMENT
TURFACE ® MVP
PARTICLE
TYPICAL
TYPICAL
SIZE
PERCENTAGE
PERCENTAGE
>2.00 mm
8.4
55.8
10 × 5 MESH
0.85-2.00 mm
81.5
40.1
20 × 10 MESH
0.60-0.85 mm
8.5
3.5
30 × 20 MESH
<0.60 mm
1.6
0.6
50 × 30 MESH
Samples of the subject invention product were submitted to numerous groundskeepers at major league baseball parks. Three out of four professional groundskeepers currently use TURFACE® MVP as a soil amendment/top dressing. All were highly enthusiastic about the product produced in accordance with the subject invention.
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Porous calcined clay sports field conditioners exhibit excellent playability while also displaying excellent drainage, freedom from compaction, and moisture retention under hot, dry conditions. The conditioners are non-hydrating granulates of narrow particle size distribution and are preferably of a red to brown coloration.
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TECHNICAL FIELD
This invention relates to a functional polymer comprising active and stable functional groups, and to a method of preparing the same. More particularly, the present invention relates to a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, and also to the cycloaddition method of its preparation.
BACKGROUND ART
Functional polymers are widely used in industry as separation media and as solid-phase reagents, catalysts and protecting groups for analytical or preparative chemical applications and processes [D. C. Sherrington and P. Hodge, “Syntheses and Separations Using Functional Polymers”, John Wiley & Sons, Toronto, 1988]. A functional polymer generally consists of a polymer matrix, in the form of particles, beads or a porous block [C. Viklund, F. Svek, J. M. J. Fréchet and K. Irgum, “Molded porous materials with high flow characteristics for separation or catalysis: control of porous properties during polymerization in bulk solution”, Chem. Mater. y1986 v8 p744-750], that is chemically inert to the conditions of its use, including being insoluble in any solvent it is likely to encounter so that it can be retained in a column or easily recovered from out of a product mixture by filtration or other separation for easy isolation of chemical product and reuse of the functional polymer; and also of functional groups, attached to the polymer matrix, that can bind, transform or otherwise interact with chemical species that are dissolved in a permeating fluid, or that confer other advantageous properties to the functional polymer, such as a higher density for best use in floating bed reactors or for easier and faster separation by precipitation, or better wetting and penetration by a particular solvent. Most often, the polymer matrix is of crosslinked polystyrene, due to the ease of its preparation through suspension or other polymerization of styrene or styrene-like monomer (usually, including divinylbenzene as crosslinking agent), with attendant control of particle size, porosity, swellability, surface area, and other aspects of its architecture affecting eventual use; and its good general mechanical and chemical stabilities, though also with the ability to be controllably decorated with any of a wide variety of functional groups. In ion exchange resins, which are manufactured in large quantities for deionizing water and many other purification processes, these functional groups may consist of sulfonic, carboxylic or phosphonic acids or their salts, or amines or their salts, or quaternary ammonium or phosphonium hydroxides or other of their salts; chelating resins that recover toxic or expensive metal ions from wastewater may contain combinations of amino and sulfonate, phosphonate or carboxylate groups, along with hydroxyl, ether, thiol, sulfide, phosphine or other Lewis base groups; certain of these groups may also coordinate with metal ions to activate their negative counterions for phase transfer catalyzed nucleophilic substitution or other reactions, or may hold platinum or other catalytic heavy metal species so that these are conserved and re-used from one reaction to the next; halosilyl, haloalkyl, haloacyl or halosulfonyl functional groups, or anhydride or azlactone functional groups, can covalently bind to other organic molecules so that parts of these are protected while other parts are being chemically modified, the whole later released, such as in solid-phase synthesis of polypeptides, polysaccharides or polynucleotides, or themselves act as agents for catalysis or molecular recognition, as with enzymes, antibodies or antigens that have been polymer-bound. Halogen-rich functional groups can improve sorption in a functional polymer [Specialty Polymers Division, “Manual of ion exchange resins and synthetic adsorbent”, Mitsubishi Kasei Corporation: Tokyo, Japan y1991 v1 p123-1321], and increase its fire-resistance, and density for separation by precipitation, while ferrous/ferric oxide precipitated around carboxylate groups can allow polymer particles to be recovered magnetically from mixtures [J. Ugelstad, U.S. Pat. No. 4,654,267 y1987].
While functional polymers may be prepared by polymerization of monomers that already contain the desired functional groups, more commonly they are made by chemically functionalizing or modifying other existing polymer matrices—most commonly, crosslinked polystyrene—as prepared from common monomers through established polymerization recipes that give well-defined and desirable particle and matrix structures and properties. However, existing such modification methods of preparing functional polymers often suffer from disadvantages of hazardous or expensive ingredients or conditions, that result in products that are intrinsically deficient in activity or stability or both [G. D. Darling and J. M. J. Fréchet “Dimethylene spacers in functionalized polystyrenes”, in J. L. Benham and J. F. Kinstle, Eds. “Chemical Reactions on Polymers”, ACS Symp. Ser. v364, American Chemical Society, Washington DC, y1988 p24-36]. For example, the chloromethylation route to the most common anion-exchange and chelating polystyrene-based resins uses or generates highly carcinogenic species, and results in benzyl-heteroatom bonds that are unstable to many conditions of eventual use or regeneration; bromination/lithiation, another general route to functional polymers, employs expensive and sensitive organometallic reagents and, like sulfonation, results in aryl-heteroatom functional groups that may be unstable in acidic conditions. Functional polymers containing aliphatic spacer groups of at least two carbons between polystyrene phenyl and functional group heteroatom would not show either type of chemical instability, and moreover, the deeper penetration of their dangling functional groups into a fluid phase permeating the polymer matrix often allows better and faster interactions with soluble species therein [A. Deratani, G. D. Darting, D. Horak and J. M. J. Fréchet “Heterocyclic polymers as catalysts in organic synthesis. Effect of macromolecular design and microenvironment on the catalytic activity of polymer-supported (dialkylamino)pyridine catalysts.” Macromolecules y1987 v20 p767]. Several such spacer-containing functional polymers have been prepared via electrophilic aromatic substitution—either chloromethylation or bromination/lithiation—of aryl nuclei in crosslinked styrene-divinylbenzene copolymer, albeit through tedious multistep syntheses [Darling and Fréchet y1988 ibid].
Instead of on styrenic phenyl, modification reactions can be performed on the vinyl groups of polymeric 1-(vinylphenyl)ethylene repeat units. These vinyl groups may be prepared from formyl, chloromethyl, bromoethyl or 1,2-dibromoethyl functional group precursors [M. J. Farrell, M. Alexis and M. Trecarten, Polymer y1983 v24 p114; Darling and Fréchet y1988 ibid; T. Yamamizu, M. Akiyama and K. Takeda, React. Polym. y1985 v3 p173], or remain from anionic [Y. Nagasaki, H. Ito, T. Tsuruta, Makromol. Chem. y1968 v187 p23] or even free-radical [M. C. Faber, H. J. van den Berg, G. Challa and U. K. Pandit, React. Polym. y1989 v11 p117] copolymerization of monomer mixtures that include divinylbenzene. Radical copolymerization with divinylbenzene is a particularly simple way to form a polymer that contains such vinyls, that moreover have here the advantage of being site-isolated; indeed, Rohm and Haas supplies a commercial product, “Amberlite® XAD-4 nonionic polymeric adsorbent”, which analysis thereof indicates to be undoubtedly made by radical copolymerization of a mixture of divinylbenzene and ethylstyrene—which mixture, containing both meta and para isomers of each, is commercially provided under the name “technical-grade divinylbenzene” [“Aldrich Catalog” y1997], and so which resulting polymer may be called “poly(divinylbenzene)”—and which contains 30 mol % of polymeric 1-(vinylphenyl)ethylene repeat units, with the remaining repeat units consisting of polymeric 1-(ethylphenyl)ethylene and crosslinking polymeric bis(ethylene)phenyl repeat units [Faber et al y1989 ibid]. Through electrophilic, nucleophilic, radical, transition-metal catalyzed or other additions to such polymeric 1-(vinylphenyl)ethylene repeat units [W. Obrecht, Y. Seitz and W. Funke, Makromol. Chem, y1976 v177 p2235; Faber et al y1989 ibid; Z. Zhengpu, P. Hodge and P. W. Stratford, React. Polym. y1991 v15 p71; J. P. Gao, F. G. Morin and G. D. Darling, Macromolecules y1993 v26 p1196], or by their radical-induced graft copolymerizations with various monomers [T. Brunelet, M. Bartholin and A. Guyot, Angew. Makromol. Chem. y1982 v106 p79], have been provided a wide variety of functional groups, including of the form Ps-CH 2 —CH 2 —X, wherein Ps represents a crosslinked polystyrene matrix connecting through phenyl, and X a functional group connecting through a heteroatom, that features advantageous dimethylene spacer [Gao et al y1993 ibid].
Useful electron-withdrawing functional groups such as halo or carboxylate may be incorporated into functional polymers through polymerizations with haloalkene, acrylic, methacrylic, maleate or fumarate comonomers. As previously mentionned though, modification of an existing optimal polymer matrix is a route often to be preferred for its simplicity, versatility, economy and better product properties. Though individual molecules of such electron-poor alkenes as maleic anhydride have been grafted onto uncrosslinked polymers to provide functionality for crosslinking and other modifications, or improve adhesion, hydrophilicity, and compatibility with other materials, both onto saturated polyalkanes like polyethylene and polypropylene in the presence of free radicals [S. W. Caywood Jr., U.S. Pat. No. 3,884,882, y1975], and onto —CH<-substituted alkene groups left in conjugated diene copolymers by non-radical ene reactions [B. C. Trivedi and B. M. Culbertson, “Maleic Anhydride”, Plenum: New York, 1982, Chapter 11]; and though non-polymeric vinylphenyl compounds have been made to undergo cycloadditions with maleic anhydride [Joseph Csapilla, U.S. Pat. No. 5,414,094, y1995] and hexachlorocyclopentadiene [M. Look, Aldrichim. Acta y1974 v7 p23 14 29 ]; and though the products of cycloaddition between polymeric (1-vinylphenyl)ethylene repeat units and electron-poor alkenes would provide a wide variety of useful functional groups on attractive and controllable polymer matrices, derived via relatively simple procedures from available starting materials—the prior art has no examples of polymeric (1-vinylphenyl)ethylene groups being modified by cycloadditions with the forementionned or any other alkenes, nor are the useful products that would be characteristic of such reactions known by any other route.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a functional polymer comprising repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene for separation or reactive processes in chemical manufacture or analysis.
It is another object of this invention to provide a functional polymer that can be prepared using readily-available materials and simple conditions and apparatus.
It is another object of this invention to provide a functional polymer, the architecture of whose polymer matrix (e.g. particle size and shape, porosity, swellability, surface area), and type, arrangement and number of whose functional groups, can be controlled.
It is another object of this invention to provide a functional polymer whose functional groups are stable, active, and accessible to a permeating fluid.
It is another object of this invention to provide a functional polymer bearing functional groups that are halo, heterocycle, carboxylic anhydride, carboxyl halide, carboxylic acid, carboxylate salt, ester, amide, imide, or polymer-supported ion, polynucleotide, polypeptide, polysaccharide, enzyme, antibody or antigen, or combinations thereof, in type, arrangement and number sufficient to confer or contribute towards acidity, basicity, ion exchange, fire-resistance, wettability, chelation, extraction, separation, sorption, density, permeability, catalysis, selectivity, hydrophilicity, reactivity, seperability, suspendability, binding of ions, binding of organic molecules, binding of polypeptides, binding of polysaccharides, binding of polynucleotides, molecular recognition, filterability, convertability to other functional groups, or other desirable qualities, or combinations thereof, in a separation medium, chromatographic medium, purification medium, ion-exchange medium, chelating medium, solid-phase reagent, solid-phase catalyst, solid-phase protecting agent, support for solid-phase synthesis, chemical intermediate, or other application of a functional polymer, or combinations thereof.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene.
In accordance with another aspect of the invention there is a provided a functional polymer that can be prepared by heating a preexisting polymer comprising polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene, without need of radicals or exclusion of oxygen.
In accordance with a preferred embodiment of the invention there is provided a method of preparing a functional polymer, by heating a polymer that comprises polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene dissolved in a fluid that permeates said polymer.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that has been prepared by heating a pre-existing polymer comprising polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, that were derived by chemical modification of structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and another electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, that were derived by reaction of a nucleophile with structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and maleic anhydride.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units of a radical copolymer of monomers comprising divinylbenzene, and an electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units of a radical copolymer of monomers consisting of meta-divinylbenzene and para-divinylbenzene and meta-ethylstyrene and para-ethylstyrene, and an electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an alkene, wherein one or more of the olefinic carbons thereof are substituted with groups that withdraw electrons by induction or resonance.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloadditioh between polymeric 1-(vinylphenyl)ethylene repeat units and a conjugated diene capable of cisoid conformation, wherein one or more of the olefinic carbons thereof are substituted with groups that withdraw electrons by induction or resonance.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, said end products having incorporated one mole of said alkene per said repeat unit.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, said end products having incorporated two moles of said alkene per said repeat unit.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene selected from maleic anhydride, maleimide, N-alkylmaleimide wherein “alkyl” is selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl and t-butyl; of the form X—CO—CH═CH—CO—Y whose geometry is selected from cis and trans and wherein X and Y are selected from Cl, O − , OR 1 and NR 1 R 2 wherein R 1 and R 2 are selected from H, Me, Et, nPr, iPr, nBu, iBu, sBu, tBu, an amino acid residue of a polypeptide a carbohydrate residue of a polysaccharide, and a nucleotide residue of a polynucleotide; hexachlorocyclopentadiene, and 3,6-di-2-pyridyl-1,2,4,5-tetrazine.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, which said functional polymer also comprises other functional groups.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, which said functional polymer also contains magnetic iron oxide.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, said structures comprising one or more functional groups selected from halo, heterocycle, carboxylic anhydride, carboxyl halide, carboxylic acid, carboxylate salt, ester, amide, imide, or polymer-supported ion, polynucleotide, polypeptide, polysaccharide, enzyme, antibody or antigen; which said functional groups are in type, arrangement and number to confer or contribute towards one or more qualities in said functional polymer selected from acidity, basicity, ion exchange, fire-resistance, wettability, chelation, extraction, separation, sorption, density, permeability, catalysis, selectivity, hydrophilicity, reactivity, separability, suspendability, binding of ions, binding of organic molecules, binding of polypeptides, binding of polysaccharides, binding of polynucleotides, molecular recognition, filterability, or convertability to other functional groups; which qualities are such as to allow or improve for one or more uses selected from separation medium, chromatographic medium, purification medium, ion-exchange medium, chelating medium, solid-phase reagent, solid-phase catalyst, solid-phase protecting agent, support for solid-phase synthesis, and chemical intermediate.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention are shown in the figures, wherein:
FIG. 1 shows embodiments of the invention 2-8, showing repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units of polymeric 1-(vinylphenyl)ethylene-containing polymer 1 with electron-poor alkenes, each either prepared by actual cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units of polymeric 1-(vinylphenyl)ethylene-containing polymer 1 with an electron-poor alkene (mechanism shown for maleic anhydride, to give embodiment 2), or in some other fashion, or both (e.g. 3 and 7) [stereochemistry not shown];
FIG. 2 shows cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units of polymeric 1-(vinylphenyl)ethylene-containing polymer 1 with hexachlorocyclopentadiene electron-poor alkene, to give an embodiment of the invention 9; and
FIG. 3 shows cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units of polymeric 1-(vinylphenyl)ethylene-containing polymer 1 with 3,6-di-2-pyridyl-1,2,4,5-tetrazine electron-poor alkene, to give an embodiment of the invention 10.
DESCRIPTION OF PREFERRED EMBODIMENTS
Vinylphenyl of polymeric 1-(vinylphenyl)ethylene repeat units is an electron-rich electron system such as are typically reactive with electron-poor electron systems for cycloaddition. When the electron-poor alkene of the invention is other than a conjugated diene capable of cisoid conformation, then typically it will react as the dienophile, and the vinyl and one adjacent internal double bond in the phenyl of a polymeric 1-(vinylphenyl)ethylene repeat unit of the invention will react as the diene, in a Diels-Alder type of cycloaddition that will link the electron-poor alkene moiety and its functional groups to the polymer by two stable covalent bonds. This first reaction step disrupts the aromaticity of said phenyl, which aromaticity however can then be restored by a subsequent ene reaction step (also formally a cycloaddition) in which a second molecule of electron-poor alkene becomes joined to the polymer by a single stable covalent bond, for a total of two molecules of electron-poor alkene binding to polymer for every reacting polymeric 1-(vinylphenyl)ethylene repeat unit (e.g. see FIG. 1, mechanism leading to structure 2; Examples 1, 2, 4, 5 below). Though aromaticity of phenyl could also be restored by a 1,3 hydride shift without addition of a second molecule of electron-poor alkene (e.g. giving structure 6 in FIG. 1 ), in fact such a rearrangement is forbidden as a concerted reaction by the rules of orbital symmetry [C. W. Spangler, Chem. Rev. y1976 v76 p187-217] (though another mechanism might be possible were acid catalyst to be present [L. T. Scott and W. R. Brunsvold, J. Org. Chem. y1979 v44 p641]), and the observed stoichiometry of the reaction, as shown by quantitative analysis of polymeric 1-(vinylphenyl) repeat units in starting polymer vs functional groups in functional polymer product, and by analogous reactions of vinylphenyl small molecules [T. Wagner-Jauregg, Synthesis y1980 p779-799], suggests the former route is dominant. Structures of products are also supported by NMR and FTIR data (e.g. showing trialkylphenyl). When the electron-poor alkene of the invention is a conjugated diene capable of cisoid conformation (e.g. see FIGS. 2 and 3, structures 9 and 10; Examples 8 and 9 below), then in the cycloaddition of the invention it acts as the diene, and the vinyl of a polymeric 1-(vinylphenyl)ethylene repeat group as the dienophile, and the stoichiometry is 1:1, as is also supported by quantitative and other analyses.
Excess of electron-poor alkene may be used, and reaction continued, until all polymeric 1-(vinylphenyl)ethylene repeat units in the starting polymer have been consumed, giving 30 mol % or more of polymeric repeat units having a structure corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with that electron-poor alkene, when starting from polymers with sufficient polymeric 1-(vinylphenyl)ethylene repeat units, such as certain poly(divinylbenzene) copolymers including commercial Amberlite® XAD-16 (Example 1 below); or a limited amount of electron-poor alkene may be employed, or the reaction terminated early, so that less than the maximum possible of polymeric 1-(vinylphenyl)ethylene repeat units have undergone cycloaddition with the electron-poor alkene, and some polymeric 1-(vinylphenyl)ethylene repeat units remain, which can either be left unreacted, or can be made to react with a different electron-deficient alkene of the invention, or made to undergo some other reaction, either at the same or some later time. Cycloaddition of the invention may also be pursued before, after or simultaneous with other modifications of a starting polymer, such as impregnation with magnetic iron oxide (Example 2 below). Also, structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with one electron-poor alkene, may be chemically modified to give other structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with another electron-poor alkene, and so which other structures are also embodiments of the invention, regardless of their actual route of preparation (e.g. structures 3 and 7 in FIG. 1; Examples 36 below). In particular, cyclic anhydride containing structure 2, where the electron-poor alkene of the invention is maleic anhydride, is a particularly versatile intermediate towards other structures of the invention, being able to react with nucleophiles such as water, hydroxide, carboxylates, alcohols or amines, including polypeptides, polysaccharides or polynucleotides, to provide functional groups that are carboxylic acids, carboxylate salts, esters, amides, or (with actual or latent primary amines, and forcing conditions) imides, including supported polynucleotides, enzymes, antibodies or antigens, or combinations thereof (see structures 3, 4, 7 and 8 in FIG. 1; Examples 3, 6, 7 and 11 below). Such chemical modifications may also be complete or partial—for example, a polypeptide, polysaccharide or polynucleotide may need only be supported on a very small fraction of total repeat units to provide a useful solid-phase catalyst or agent for molecular recognition. In all these ways, a functional polymer of the invention that comprises particular repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene, may or may not comprise other repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with one or more other electron-poor alkenes, and may or may not comprise other repeat units having other structures or functional groups, possibly contributing other desirable qualities of density, solvent wettability or permeability, dispersability, stabilization of magnetic or other loaded particles, buffering capacity, or other desirable qualities, or combinations thereof.
In the examples below, various qualities and utilities of several preferred embodiments the invention are demonstrated: 2 and 5 as chemical intermediates, protection agents, and for covalently binding and supporting organic molecules or biomoiecules (Examples 1-4, 6, 7, 10), 3 and 4 as solid-phase buffer of acid or base, and for titration analysis (Examples 1-3, 5, 10), 9 to increase polymer density (Example 8), 10 as a chelating agent (Example 9), 11 as a solid-phase catalyst (Example 10). It is apparent that modifications and adaptations of these specifically described embodiments will occur to those skilled in the art; however, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention.
EXAMPLES
The following examples describe preferred embodiments of the present invention. Reagents and solvents were used as received unless otherwise indicated. Polymeric 1-(vinylphenyl)ethylene-containing poly(divinylbenzene) polymer 1a was prepared by polymerization of a divinylbenzene:ethylstyrene 55:45 mixture with toluene as porogen, and assayed for polymeric 1-(vinylphenyl)ethylene repeat units by FTIR (M. Bartholin, G. Boissier, J. Dubois, Makromol. Chem. y1981 v182 p2075-20851. Samples of commercial Amberlite® XAD-4 and XAD-16 were obtained as gifts from Supelco and, after washing in distilled water, extracting by Soxhlet with methanol, and drying, showed FT-IR spectra matching peak-to-peak that of 1a, indicating each of them also to be poly(divinylbenzene) comprising polymeric 1-(vinylphenyl)ethylene repeat units, and so were respectively denoted 1b and 1c. In general, 100-500 μm beads of 1a-c were degassed under vacuum 30-60 min, then purged with nitrogen prior to use. FT-IR spectra of dry ground samples spread onto IR-transparent silicon wafers were recorded using an IR microscope in transmittance mode. 13 C CP-MAS (cross polarization/magic angle spinning) and 13 C CP-MAS-DD (also with π=45 ms dipolar dephasing; in the peak lists following, those labeled “DD” persist here) NMR spectra were obtained on a 100 MHz solid-phase NMR spectrometer; the program “C-13 NMR Module” (Softshell, Grand Junction CO USA) helped assign the peaks. Elemental analyses were done by Robertson Microlit Laboratories (NJ). Back titrations of polymeric acid were done by presoaking the polymer beads in a measured excess of 1.00 N NaOH (aq) :THF 5:1 for 24 h, then titrating aliquots of the supenatant with standardized 1.00 N HCl (aq) . Ash was weighed after heating the sample in a ceramic crucible at 400° C. for 24 h, converting all iron to Fe 2 O 3 , then cooling. X f designates mole fraction of indicated repeat units among total repeat units.
Example 1
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with maleic anhyndee electron-poor alkene (2). To 0.34 X f poly(divinylbenzene) beads prepared with toluene as porogen 1a (11.46 g, 32.66 mmol) was added a solution of maleic anhydride (3.50 g, 35 mmol) in 50 mL toluene (bp 111° C.). The mixture was refluxed 12 h and the beads filtered while hot. The beads were then washed with 30 mL hot toluene 9X, 30 mL acetone 7X, then ether, and dried in a vacuum oven 48 h at 60° C., yielding 14.88 g 2a as light beige beads: IR (Si wafer) 1868 (w), 1789 (s), 1728 (w), 1630 (w, weaker than 1a), 1217, 990 (w, weaker than 1a), 890-910 (br) cm −1 ; 13 C CP-MAS NMR δ 171 (DD, COOCO), 145 (DD, disubstituted aryl C-R), 135 (DD, trisubstituted aryl C-R) and 127 (aryl C-H) ppm, 40, 30 and 22 ppm (alkyl CH and CH 2 ), and 15 ppm (DD, CH 3 ). Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.37 -(C 18 H 14 O 6 ) 0.18 (48% conversion): mmol acid/g, 4.33. Found: mmol acid/g (3 titrations against 1 blank), 4.33±0.17.
Refluxing, with tenfold excess maleic anhydride in o-xylene at a higher temperature (bp 120° C.), commercial Amberlite® XAD-4 beads of same 0.34 X f vinyl content 1b for the same 12 h time, gave 2b product showing titration results (mmol acid/g, 4.33±0.04) and spectra corresponding to a functional group content that was not significantly different from the polymeric 1-(vinylphenyl)ethylene content of 1a, i.e. still corresponding to 0.18 X f of bis-anhydride groups of structure 2. With Amberlite® XAD-16 beads of 0.35 X f polymeric 1-(vinylphenyl)ethylene-containing polymer 1c, titration data showed that content of bis-anhydride in 2c continued to increase, past 0.24 X f (mmol acid/g, 5.75±0.06) at 12 h, 0.28 X f (mmol acid/g, 5.94±0.04) at 25 h, up to 0.32 X f (mmol acid/g, 6.66±0.14) at 48 h, with accompanying decrease and eventual disappearance of IR peaks at 1630 and 990 cm −1 .
Example 2
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with maleic anhydride electron-poor alkene (2)—magnetite-impregnated. Amberlite® XAD-16 beads of 0.35 X f polymeric 1-(vinylphenyl)ethylene-containing polymer 1c (9.00 g, 26.1 mmol) were soaked in a 100 mL methanol solution containing FeCl 2 (5.00 g, 40.0 mmol) and FeCl 3 (5.00 g, 31.0 mmol) for 12 h at room temperature in air, then filtered. The moist beads were then transferred to an Erlenmeyer flask containing 250 mL of 1 M NH 3(aq) and boiled gently in air for 30 min. The resulting dark brown beads were then filtered over 425 mm wire mesh and washed with boiling water several times until filtrate was clear and colourless. The beads were then dried in vacuo 3 days at 75° C. until constant weight, giving 10.11 g of dark brown beads, 1d. To 4.00 g of these was added a solution of maleic anhydride (5.00 g, 50 mmol) in 30 mL o-xylene. The suspension was heated to 120° C. for 48 h and the beads filtered off while hot. The beads were then washed with 30 mL hot toluene 9X, 30 mL acetone 7X, then ether, and dried in a vacuum oven for 48 h at 60° C., yielding 4.33 g of 2d as dark brown beads: FT-IR (Si wafer) same as from 2 a . Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.36 (C 18 H 14 O 6 ) 0.19 (Fe 3 O 4 )0.039 (54% conversion, 5 wt % magnetite): mmol acid/g, 4.28; ash, 5.27. Found: mmol acid/g, 4.34; ash, 5.23. Similar results were obtained by impregnating, with magnetic iron oxide, beads that had already been reacted with maleic anhydride.
Example 3
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with disodium maleate (3) or maleic acid (4) electron-poor alkenes. A sample of 2a was treated with aqueous base as for the pH back titration procedure, and the resulting 3a examined spectroscopically: FT-IR (KBr) 3600-100, 1572, 1406, 1217 cm −1 ; 13 C CP-MAS NMR δ 184 (DD), 145 (DD), 138 (DD), 127, 40, 30, 32, 15 (DD). Back titration protonated this to 4a.
Example 4
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with fumaryl chloride electron-poor alkene (5). Amberlite® XAD-16 beads of 0.35 X f polymeric 1-(vinylphenyl)ethylene-containing polymer 1c (9.00 g 26.1 mmol) were soaked in 30 mL o-xylene that had been dried over molecular sieves, then fumaryl chloride (16.01 g, 105 mmol) was added. The mixture was then heated 24 h at 120° C., then filtered hot, and the residue washed with toluene 16X, then ether, then dried in vacuo 3 days at 75° C. until constant weight, yielding 11.11 9 of 5 as tan beads: FT-IR (Si wafer) 1792, 1727 cm −1 ; 13 C CP-MAS NMR δ 166, 145 (DD), 127, 40, 28, 15 (DD). Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.38 (C 18 H 14 O 4 Cl 4 ) 0.17 (53% conversion): mmol acid/g, 7.43. Found: mmol acid/g, 7.61.
Example 5
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with N-ethylmaleimide electron-poor alkene (7). By reaction of 1 with N-ethylmaleimide. Amberlite® XAD-16 beads of 0.35 X f polymeric 1-(vinylphenyl)ethylene-containing polymer 1c (2.5 g, 7.25 mmol) was soaked with 10 mL o-xylenes, and N-ethylmaleimide (2.50 g, 20.0 mmol) was then added. The mixture was heated at 120° C. for 24 h, then filtered hot, and washed with toluene 16X, then ether. The beads were then dried in vacuo 3 days at 75° C. until constant weight, yielding 3.53 g of 7 as tan beads: FT-IR (Si wafer) 1791, 1726 cm −1 ; 13 C CP-MAS NMR δ 166 (DD), 145 (DD), 127, 40, 28, 15 (DD). Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.27 (C 22 H 24 O 4 N 2 ) 0.28 (80% conversion): C, 79.77; H, 7.43; N, 3.27. Found: C, 80.67; H, 7.01; N, 3.27.
Example 6
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with N-ethylmaleimide electron-poor alkene (7). By reaction of 2 with N-ethylamine. Beads of 0.32 X f polymer-supported bis-anhydride 2c derived from Amberlite® XAD-16 (1.00 g, 3.33 mmol anhydride) was added to 70 wt % aqueous ethylamine (2 mL, 30 mmol) and 8 mL THF, then heated 1 h at 40° C. The beads were then filtered and transferred to a 25 mL round bottom flask containing 10 mL o-xylene, and heated to 120° C. for 2 h, then filtered hot and washed several times with ethanol and ether. The beads were then dried in vacuo 24 h at 70° C., yielding 1.05 g of 7 as white beads: FT-IR as above, except for more significant peaks at 3400 (m, br) and 1870, and a broader one at 1790 cm −1 . Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.23 -(C 18 H 14 O 6 ) 0.05 (C 22 H 24 O 4 N 2 ) 0.27 (84% conversion): C, 78.59; H, 7.19; N, 3.63. Found: C, 78.22; H, 7.22; N, 3.61.
Example 7
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with maleimide electron-poor alkene (8). Beads of 0.18 X f polymer-supported bis-anhydride 2b derived from Amberlite® XAD-4 (1.00 g, 2.17 mmol anhydride) were suspended in 5 mL triglyme containing “99% grade” urea (0.70 g, 12 mmol) and heated to 150° C. for 1 hour, then filtered hot and washed with hot toluene and hot ethanol, then ether. The beads were dried in vacuo, yielding 0.93 g of 8 as light beige beads: FT-IR (Si wafer) 1782, 1716 cm −1 ; 13 C CP-MAS NMR δ 169 (DD), 145 (DD), 135 (DD), 127, 40, 30, 22, 35 15 (DD). Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.37 (C 18 H 14 O 6 ) 0.08 (C 18 H 16 O 4 N 2 ) 0.10 (56% conversion): N, 1.69. Found: N, 1.76.
Example 8
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with hexachlorocyclopentadiene electron-poor alkene (9). Amberlite® XAD-16 beads of 0.35 X f polymeric 1-(vinylphenyl)ethylene-containing polymer 1c (4.0 g. 11.60 mmol) were soaked with 10 mL toluene, and hexachlorocyclopentadiene (4.1 g, 15.0 mmol) was then added. The mixture was heated for 16 h at 125° C., then filtered hot, and washed with toluene 6X, ethanol 4X then ether. The beads were then dried in vacuo 3 days at 75° C. until constant weight, yielding 5.50 g of 9 as tan beads: FT-IR (Si wafer) 1269, 1209, 1154, 1097, 1063 cm −1 . Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.42 (C 15 H 10 Cl 6 ) 0.13 (38% conversion): Cl, 16.70. Found: Cl; 16.75. These beads settled more quickly in methanol than beads of Amberlite® XAD-4 poly(divinylbenzene).
Example 9
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with 3,6-di-2-pyridyl-1,2,4,5-tetrazine electron-poor alkene (10). Amberlite® XAD-16 beads of 0.35 X f polymeric 1-(vinylphenyl)ethylene-containing polymer 1c (2.0 g, 5.80 mmol) were soaked with 10 mL DMF containing 3,6-di-2-pyridyl-1,2,4,5-tetrazine (1.1 g, 6.0 mmol), degassed, and purged with O 2 , then a few drops of conc. ammonium hydroxide were added. The mixture was stirred for 24 h at 25° C. during which the deep red colour changed to yellow, and until gas evolution (N 2 ) ceased, then filtered and washed with toluene 6X, ethanol 4X, then ether. The beads were then dried in vacuo 2 days at 35° C. until constant weight, yielding 3.00 g of 10 as very light yellow beads: FT-IR (Si wafer) 1269, 1209, 1154, 1097, 1063 cm −1 . Anal. Calcd for (C 10 H 12 ) 0.45 (C 10 H 10 ) 0.02 (C 15 H 10 Cl 6 ) 0.34 (98% conversion): mass increase: +1.00 g. Found: mass increase: +1.00 g. This functional polymer was able to chelate iron, nickel and copper ions out of aqueous solution to less than 1 mmol concentration.
Example 10
Functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with maleic acid acyl-lipase electron-poor alkene (11). Candida cylindricea lipase (freshly precipitated from n-propanol) was suspended in 100 mM pH 7 aqueous phosphate buffer, and shaken with ethyl butyrate and beads of 0.18 X f polymer-supported bis-anhydride 2b derived from Amberlite® XAD-4, in the proportions of 100 mg enzyme: 4 mL buffer. 0.1 mL ethyl butyrate: 1 g polymer, at 22° C. for 12 hours. The mixture was then filtered, and the residue washed liberally with buffer. Assay of the filtrate for protein by the Peterson-modified Lowry method (Sigma Chemical Co. kit cat# P5656) indicated, by difference, a protein content in the residue of 45 mg/g polymer. Filtrate from washing this solid with 1% SDS/H 2 O showed no colour reaction with ninhydrin, indicating the lipase to have become covalently bound to polymer as 11b (unlike other enzyme merely precipitated and adsorbed onto Amberlite® XAD-16). As measured by titration with 0.100 N NaOH to pH 7.50 in a Radiometer RTS 822 pHstat on 0.5 M ester dissolved or suspended with 11b (22 mg total, 1 mg bound enzyme) in 10 mL of 10 mM pH 7 aqueous phosphate buffer, polymer-bound lipase lib catalyzed hydrolysis of esters at the rate of 2.00 μmol ester/min/mg enzyme for butyl acetate, 1.92 μmol/min/mg for ethyl acetate, and 0.28 μmol/min/mg for methyl acetate. After recovery by filtration and washing, recycled polymer-bound enzyme proved catalytically active in later hydrolyses.
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A functional polymer having active and stable functional groups useful for separation or reactive processes in chemical manufacture or analysis is disclosed. The polymer comprises repeat units having structures corresponding to cycloaddition products of polymeric 1-(vinylphenyl)ethylene with electron-poor alkenes. A process for preparing the functional polymer does not require radical reactions or the exclusion of oxygen. The properties of the polymeric matrix produced can be adjusted by modifying the polymer. For example, the polymer particle size and shape, porosity, swellability, surface area, and number, type and distribution of functional groups may be controlled.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to injector apparatus for guiding coiled tubing and inserting the coiled tubing into a well, and more particularly, to an injector with a guide portion having guide strips rather than rollers for guiding the tubing as it is moved through the apparatus.
2. Description of the Prior Art
After a well has been completed, it is necessary to periodically service the well. There are many occasions where the service procedure is carried out using coiled tubing. Such tubing is relatively small in diameter and is inserted into the wellhead through a lubricator assembly or stuffing box. Typically, there is a pressure differential in the well so that the well is a closed chamber producing oil or gas or a mixture thereof from the pressurized well. The tubing that is inserted into the well is normally inserted through a lubricator mechanism which seals the well for pressure retention in the well. The tubing is inserted by an injector which generally incorporates a set of blocks which straighten the tubing. The tubing is flexible and can bend around a radius of curvature and is supplied on a drum or reel and spooled off by the injector.
One such injector is the Otis reeled tubing injector which utilizes grooved gripper blocks which are attached to a gripper chain. There are a pair of such chains positioned on opposite sides of the tubing. Each gripper chain is driven by a drive sprocket and guided by an idler sprocket which are rotatably mounted in a rigid frame.
A curvilinear gooseneck tubing guide apparatus forms an upper portion of the injector. This gooseneck tubing guide includes a curvilinear first frame portion with a set of rollers thereon which support and guide the tubing as it is moved through the injector. Spaced from the first frame portion is a second frame portion also having a set of rollers thereon which are on the opposite side of the tubing from the first set of rollers and which also act to guide the tubing. The gooseneck tubing guide is pivotable for easy alignment with the tubing reel.
The rollers on the gooseneck tubing guide are subjected to weather and also to well fluids which might drip from the tubing when it is moved out of the well. Either of these can cause the rollers to rust or become dirty which may prevent them from rolling. A stuck or frozen roller will cause increased friction when moving the tubing into or out of the well which might result in damage to the tubing. This requires frequent replacement of the bearings in the rollers or total replacement of the rollers themselves.
The present invention solves this problem with the prior art tubing injector by replacing the rollers with tubing guide strips or tracks which are preferably made of advanced plastics which are substantially self-lubricating. In this way, the tubing may be slidingly moved along these guide strips without significant frictional restrictions.
SUMMARY OF THE INVENTION
The tubing injector apparatus of the present invention comprises a tubing guide apparatus or portion and a tubing injector apparatus or portion. The guide apparatus comprises an elongated first frame, an elongated second frame spaced from the first frame, an elongated first guide track or strip attached to the first frame and having a first tubing guide surface thereon, and a second guide track or strip attached to the second frame and spaced from the first guide track. The second guide track defines a second tubing guide surface thereon. The first and second tubing guide surfaces are adapted for sliding engagement with tubing moved by the injector portion. In the preferred embodiment, the first and second frames are curvilinear and substantially parallel to one another, and the first and second guide tracks conform to the curvature of the first and second frames.
The first tubing guide surface defines an elongated groove therein adapted for receiving at least a portion of the tubing. Preferably, this groove has a substantially V-shaped cross section originally, but the invention is not intended to be limited to this particular configuration. The second tubing guide surface preferably has a substantially flat configuration as viewed in cross section.
In one embodiment, but not by way of limitation, the second frame is shorter than the first frame, and the second tubing guide track is shorter than the first tubing guide track.
The first and second tubing guide tracks are preferably made of a substantially self-lubricating material, such as an advanced plastic material. One preferred material is ultra-high molecular-weight crosslink polyethylene, although additional materials may also be suitable. The first and second tubing guide tracks may be manufactured in a curved form originally or the material thereof may be sufficiently flexible to allow the guide tracks to be bent to conform to the curvature of the first and second frames, respectively.
Numerous objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side elevational schematic of a prior art tubing injector.
FIG. 2 is a vertical cross section of the gooseneck tubing guide portion of the prior art tubing injector.
FIG. 3 shows a prior art cross section taken along lines 3--3 in FIG. 2.
FIG. 4 illustrates a vertical cross section through the gooseneck tubing guide portion of the tubing injector apparatus with tubing guide strips of the present invention.
FIG. 5 is a cross section taken along lines 5--5 in FIG. 4.
FIG. 6 shows a detailed cross section of the top guide strip.
FIG. 7 shows a detailed cross section of the bottom guide strip as initially installed.
FIG. 8 is a detailed cross section of the bottom guide strip illustrating wear thereon as a result of sliding movement of the tubing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and more particularly to FIGS. 1-3, a prior art Otis reeled tubing injector apparatus is shown and generally designated by the numeral 10. Apparatus 10 is positioned over a wellhead 12 which is provided with a stuffing box or lubricator 14. Tubing 16 is provided to apparatus 10 on a large drum or reel 18, and typically is several thousand feet in length. The tubing is in a relaxed, but coiled, state when supplied from drum or reel 18. As tubing 16 comes off drum 18, it normally will pass over a measuring device 20.
The well is typically pressure isolated. That is, entry of tubing 16 into the well must be through stuffing box 14 which enables the tubing, which is at atmospheric pressure, to be placed in the well which may operate at higher pressures. Entry into the well requires that the tubing be substantially straight. To this end, apparatus 10 incorporates an injector portion 22 which is constructed with drive chains which carry blocks adapted for gripping tubing 16. The details of drive chains and blocks 24 are known in the art.
A gooseneck tubing guide portion is attached to the upper end of injector portion 22. Typically, tubing guide portion 26 is pivotable about a vertical axis with respect to injector portion 22.
Gooseneck tubing guide portion 26 includes a curvilinear first or bottom frame 28 having a plurality of first or bottom rollers 30 rotatably disposed thereon. Bottom frame 28 includes a plurality of lightening holes 32 therein.
Spaced from bottom frame 28 is a second or top frame 34 which has a plurality of second or top rollers 36 rotatably disposed thereon. Top rollers 36 generally face at least some of bottom rollers 30. In the embodiment illustrated, the length of curvilinear top frame 34 is less than that of curvilinear bottom frame 28. The distal end of top frame 34 is attached to bottom frame 28 by a bracket 38.
Referring now to FIG. 3, bottom rollers 30 have a circumferential groove 40 therein, and top rollers 36 have a similar circumferential groove 42 therein. Facing rollers 30 and 36 are spaced such that tubing 16 is generally received in grooves 40 and 42 to guide and straighten the tubing as it enters injector portion 22 of apparatus 10.
Bottom rollers 30 are supported on first shafts 44, and similarly, top rollers 36 are supported on second shafts 46. Shafts 44 are disposed through a plurality of aligned pairs of holes 48 in bottom frame 28. Shafts 46 are disposed through holes 50 in top frame 34. Rollers 30 and 36 are supported on shafts 44 and 46, respectively, by bearings (not shown).
Referring now to FIGS. 4 and 5, the tubing injector apparatus with guide blocks of the present invention is shown and generally designated by the numeral 60. Apparatus 60 includes the same injector portion 22 as prior art apparatus 10. Apparatus 60 also includes a gooseneck tubing guide portion 62 which is pivotally attached to injector portion 22 by a base 63 in a manner identical to prior art apparatus 10.
Tubing guide portion 62 of the present invention comprises the same frame components as prior art tubing guide portion 26. That is, tubing guide portion 62 has curvilinear first or bottom frame 28 extending upwardly from base 63. A curvilinear second or top frame 34 also extends upwardly from base 63. Top frame 34 is spaced from bottom frame 28 and substantially parallel thereto. In the illustrated embodiment, top frame 34 is shorter than bottom frame 28. The same bracket 38 attaches the distal end of top frame 34 to bottom frame 28.
The terms "top" and "bottom" as used herein relate to the fact that bottom frame 28 is always substantially below tubing 16, and top frame 34 is always substantially above the tubing. Of course, as tubing 16 enters injector portion 22, it is substantially vertical.
Rather than the prior art rollers, tubing guide portion 62 of the present invention utilizes a first or bottom fixed guide strip or track 64 and a second or top fixed guide strip or track 66 spaced from the bottom guide strip. Top guide strip 66 is substantially parallel to bottom guide strip 64, and in the illustrated embodiment, is shorter than the bottom guide strip. Bottom guide strip 64 is an elongated member which generally follows the curvature of bottom frame 28. Bottom guide strip 64 may be originally formed in this curvilinear shape or may be made of a material which is flexible enough to conform to such curvature. Similarly, top guide strip 66 generally follows the curvature of top frame 34. Top guide strip 66 may also be originally formed with a curvature or made of a material which is flexible enough to conform to the curvature of top frame 34. As will be further discussed herein, this flexible material may be an advance plastic.
In the preferred embodiment, bottom guide strip 64 is attached by bolts or screws 68 which extend through holes 48 in bottom frame 28 and engage the bottom guide strip. In a similar fashion, a plurality of bolts or screws 70 extend through holes 50 in top frame 34 to engage top guide strip 66 and hold it in place. Thus, it will be seen by those skilled in the art, that the prior art apparatus 10 may be modified to the configuration of new apparatus 60 by removing rollers 30 and 36 and shafts 40 and 46 and attaching bottom guide strip 64 and top guide strip 66 with bolts 68 and 70 through existing holes 48 and 50.
In the embodiment shown, top guide strip 66 has a tubing guide surface 72 which faces bottom guide strip 64. Bottom guide strip 66 has a tubing guide surface 74 which generally faces tubing guide surface 72 of top guide strip 66. Tubing guide surface 74 on bottom guide strip 64 may be referred to as a first tubing guide surface, and tubing guide surface 72 on top guide strip 64 may be referred to as a second tubing guide surface. First and second tubing guide surfaces 74 and 72 are spaced from one another and are substantially parallel. As seen in FIG. 5, second tubing guide surface 72 is substantially flat as seen in cross section. First tubing guide surface 74 is at least partially flat, but preferably defines an elongated V-shaped groove 76 therein. These configurations are illustrated in enlarged detail in FIGS. 6 and 7. Other groove shapes may also be used.
Bottom guide strip 64 and top guide strip 66 are spaced such that tubing 16 will extend partially into groove 76 in bottom guide strip 64, and an opposite side of tubing 16 will generally contact flat surface 72 of top guide strip 66.
Bottom and top guide strips 64 and 66 are preferably made of a generally self-lubricating material such as an advanced plastic. One preferred material is ultra-high molecular-weight, crosslinked polyethylene, but the invention is not intended to be limited to such material.
As injector portion 22 moves tubing 16 in or out of the well, the tubing will slide along second tubing guide surface 72 and in groove 76 of first tubing guide surface 74. Eventually, groove 76 in bottom guide strip 64 will wear to the configuration indicated by numeral 64' in FIG. 8. That is, as the tubing moves along groove 76 it will eventually wear into a generally curved groove 76'. However, it has been shown that even with such wear, tubing guide portion 62 functions essentially as well as when bottom guide strip 64 is in the original configuration shown in FIG. 7. That is, wear on bottom guide strip 64 does not cause rapid degradation in the movement of tubing 16 through apparatus 60.
Eventually, of course, bottom and top guide strips 64 and 66 may need to be replaced. This is done by simply removing bolts 68 and 70 and installing new guide strips. The repair frequency on guide strips 64 and 66 has been shown to be considerably less than is necessary for repairing or replacing rollers 30 and 36 in prior art apparatus 10. Also, the cost of the two guide strips 64 and 66 is much less than the plurality of rollers in the prior art device.
It will be seen, therefore, that the tubing injector apparatus with guide strips of the present invention is well adapted to carry out the ends and advantages mentioned, as well as those inherent therein. While a presently preferred embodiment of the invention has been shown for the purposes of this disclosure, numerous changes in the arrangement and construction of parts may be made by those skilled in the art. All such changes are encompassed within the scope and spirit of the appended claims.
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A tubing injector apparatus for guiding coiled tubing and inserting the tubing into a well. The apparatus includes a tubing guide portion which has a curvilinear first frame and a curvilinear second frame spaced from the first frame. An elongated first guide track is attached to the first frame, and a second guide track is attached to the second frame. The guide tracks are adapted for sliding engagement by the tubing as the tubing is moved through the injector apparatus. The guide strips are preferably made of a self-lubricating material so that the tubing moves easily.
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FIELD OF THE INVENTION
The present invention relates to a do-it-yourself electrical distribution system that utilizes an extensible raceway that includes extension cords connecting outlet boxes that can be mounted at varying positions along the raceway. The system permits easy installation of external outlets that can be placed at various distances along the raceway.
BACKGROUND OF THE INVENTION
Wall outlets provide access to electrical service in buildings and home. It is not unusual, especially in older structures, that it is desired to provide additional outlets along or up a wall to accommodate the installation of additional electrical equipment. A wide variety of so-called “power strips”, track systems and cordless extension systems have been designed and provided for this purpose. The installation of conventional track systems generally requires “hard wiring” of the system into the existing electrical system of the structure. This tends to be complicated and dangerous for the homeowner. To overcome this problem, systems such as that described in U.S. Pat. No. 5,603,621 to Elmouchi, that include an adaptor that enables manual electrical coupling between a conductor strip and a conventional duplex wall outlet when the adaptor is positioned over the face of the outlet have been designed. U.S. Pat. No. 5,306,165 to Nadeau describes an electric power distribution system that plugs into an existing outlet and along which various wall outlets may be positioned. U.S. Pat. No. 2,979,686 to Longmire shows a raceway plugged into an existing wall outlet that may be extended using a series of additional raceways to form an arrangement where an electrical plug can be plugged into the raceway at varying lengths.
While all of the foregoing provide useful solutions to the problem of adding electrical distribution inside of a structure without hard wiring, there remains the problem of terminating the raceway contained wiring or conductor strip when the length of the section of raceway purchased does not exactly meet the length required for a particular installation. For example, if one were running such a strip along the base of a wall from a point that required a turn at a corner two feet, three and one half inches from the last junction, it would be necessary to cut the purchased strip to obtain such an odd length. This poses the problem of joining the next strip section, to that already cut, at the corner. A similar problem could occur in any installation and for a variety of reasons.
SUMMARY OF THE INVENTION
The present invention provides a simplified extensible raceway for electrical outlets comprising a cutable raceway that includes an electrical extension cord that can plug into an existing outlet and be extended in any direction by connection within the raceway to electrical outlet box that engages the raceway and an existing supporting structure and includes an additional pair of electrical extension cords having both male and female ends. Terminal electrical outlet boxes are also provided.
DESCRIPTION OF THE DRAWING
FIG. 1 is a partially blown-apart view of the electrical outlet raceway of the present invention.
DETAILED DESCRIPTION
As shown in FIG. 1, the electrical outlet raceway system of the present invention comprises raceway 10 , outlet box(es) 12 , electrical outlet(s) 14 , and male 15 and female 17 connector equipped extension cords 16 and 18 . Attachment plates 20 , and 22 , whose function will be explained hereinafter, are mounted on surface 24 to which the raceway system is being attached.
Raceway 10 is preferably manufactured from a material that is easily cut to length such as a plastic. Since extension cords 16 and 18 , described below, already have an insulation layer thereon, raceway 10 could be fabricated from an easy to cut metal such as aluminum or some other thin gauge metal.
Each of outlet boxes 12 include breakaway channel entries 28 on all four sides and slots 30 in their side walls for engagement with tabs 32 on outlet mounting plates 20 . Each of electrical outlets 14 has connected thereto or integrated therewith at least one extension cord 16 and/or 18 . In the case where the initial connection is being made with an existing electrical outlet 26 , the electrical outlet 14 is equipped with a single extension cord 34 having a male connector 36 whose tines extend at right angles from extension cord 34 to make installation easier. In the case of the terminal electrical outlet 36 , it is equipped with a single male connector 15 equipped extension cord 16 since a second extension cord is not required.
Those outlet mounting boxes 12 that include an electrical outlet 14 have a cover plate 38 that includes openings for electrical outlets 14 . Cover plates 38 include a screw hole 40 for insertion of screw 42 that secures electrical outlet 14 in outlet box 12 . Cover plate 38 is preferably formed as an integral unit with outlet box 12 , but may also be a separate unit attached to outlet box 12 by means of screws (not shown). In the case of the initial attachment of the raceway system of the present invention with the existing outlet 26 , a solid cover plate 44 is included in outlet box 12 .
Raceway cover 52 having flanges 54 that engage mating flanges 56 on raceway 10 provide the means for closing raceway 10 after installation as described below.
In the case where it is necessary to carry the raceway system of the present invention around a corner, an angular raceway section 50 can be provided. In the alternative, a miter may be cut in the top and bottom surfaces of raceway 10 and raceway 10 then bent around the corner using its rear surface to hold it together. In the case of an outside angled corner, an appropriate raceway member formed for such purpose is used.
Installation of the raceway system of the present invention is accomplished by selecting an existing outlet 26 from which it is desired to extend further outlets. The conventional cover plate (not shown) is removed and outlet-mounting plate 22 attached about existing outlet 26 . At those locations where it is desired to mount an outlet box, outlet mounting plate(s) 20 are attached to surface 24 using appropriate fasteners. Outlet mounting plate 22 is a modified version of mounting plate 20 having an opening at the center thereof to permit access to existing outlet 26 while providing tabs 32 for attachment of outlet box 12 thereover. Sections of raceway 10 are then cut to the appropriate length, if necessary, and applied to surface 24 extending in the direction that installation of additional outlets is desired, either vertically or horizontally as shown in the FIG. 1 . Raceway sections 10 may be attached to the wall or held in place by engagement of the openings provided by removal of break away channel entries 28 in outlet box(es) 12 with raceway 10 . It is preferred that mounting plates 20 be attached to surface 24 using some appropriate fastener or adhesive. Once mounting plates 20 and raceway 10 are properly sized and secured, the appropriate type of outlet box 12 , terminal, in-line or initial connection, is installed at each of the appropriate locations, as shown in FIG. 1, by engaging tabs 32 with slots 30 . The various extension cords 16 and 18 are then plugged together and inserted into raceway 10 . As is apparent, when a section of raceway 10 has been shortened by cutting, extension cords 16 and 18 are “shortened” by folding or otherwise inside of raceway 10 . If electrical outlets 14 are located at the ends of several sections of raceway 10 , an appropriate length of extension cord can be installed in raceway 10 therebetween. Cover 52 is then snapped into place over raceway 10 by engagement of flanges 54 and 56 . Finally, connection of the installed system is made to existing electrical outlet 26 and the final outlet box 12 , having a planar cover plate 48 in lieu of an electrical outlet, engaged with modified mounting plate 22 , to complete the installation.
As the invention has been described, it will be apparent to those skilled in the art that the same may be varied in any ways without departing from the spirit and scope thereof. Any and all such modifications are intended to be included within the scope of the appended claims.
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A simplified extensible raceway for electrical outlets including a cutable raceway that includes an electrical extension cord that can plug into an existing outlet and be extended in any direction by connection within the raceway to electrical outlet box(es) that engage the raceway and an existing supporting structure. The raceway and associated electrical outlet system can be extended by the addition of additional pairs of electrical extension cords having both male and female ends connected to additional electrical outlets.
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FIELD OF THE INVENTION
The present invention relates generally to built in self-test (BIST) systems for use in semiconductor devices, and more particularly, to a system and method for controlling execution of device BIST testing based on thermal feedback information from the chip.
DESCRIPTION OF THE PRIOR ART
Chip designers are starting to imbed thermal measurement devices in order to be able to control the functional behavior of the chip to avoid thermal runaway, to minimize power consumption, or to be able to keep a section of the chip operating within a certain temperature range.
As chip designs become ever more complex, built-in-self-test (BIST) mechanisms become more prevalent. As such, there is an ever-increasing gap between how a chip is being used functionally and how it is being tested. It is quite conceivable that with disabled functional power-saving methods such as clock gating and voltage islands coupled with structured self-test methods deployed at other than nominal test conditions, the chip, or sections of the chip, may run considerably hotter at the tester than they might perhaps run in the customer's functional environment.
FIG. 1A depicts a plot 10 of the interaction between temperature and BIST test and particularly, the relationship between temperature vs. BIST test time. As shown in FIG. 1A , a BIST test failure results due to the temperature of the testing environment exceeding a pre-determined limit 15 pending to a thermal runaway condition 19 . Essentially in FIG. 1A , a first operating BIST test temperature threshold 15 may be exceeded that would indicate potential false fails recorded.
These challenges have already been addressed in the burn-in arena, where various methods are being pursued as a means of curtailing severe device leakage in order to prevent thermal runaway. Particularly, when BIST testing SRAMs or other high power circuits, it is quite conceivable that entire sections of the chip may need to be cordoned-off or ignored during test in order to maintain the local temperature within the operating range for particular memories under test. If the temperature is not maintained properly it may even be necessary to ignore the test results of those memories within the particular section.
More specifically, it is critical to monitor events and criteria that may potentially indicate the likelihood that a BIST test thermal runaway condition could occur. Particularly:
as device background leakage continues to rise (especially at burn-in and dynamic voltage screen corners),
as AC BIST methods being developed are such that memories are run much faster during test and therefore switching activity increases,
as large amounts of memory on a die are being pursued by system-on-a-chip designers,
as power saving architectures which exploit clock gating of memories such that only a small subset of the memories are being used concurrently in the system for functional operations,
and, as the temperature across the die may vary dramatically during test. . . .
the very real possibility of the above-mentioned thermal runaway condition becomes more prevalent.
In today's BIST test approaches, the problem becomes particularly acute for embedded memories on a die that are all continually self-tested in parallel at elevated voltage and temperature conditions. As such, embedded memory designs run the risk of temperature limits being reached or exceeded thus rendering such continuous and parallel self-testing of all memories on a die not possible.
It would be desirable to provide a system and method for determining operating chip temperature during BIST testing and dynamically controlling (throttling BIST test activity or shutting down) the BIST test mechanisms according to temperature information fed back to the BIST machine.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a system and method for controlling a BIST (built-in-self-test) state machine utilizing digital feedback from a local, on-chip thermal sensor device. A constant monitoring of the thermal sensor enables the BIST designer to program the BIST to either: a) ignore the results of BIST for memories within a specified proximity of the thermal sensor that has registered a specified upper temperature limit (this works well for pass/fail BIST mode, but not for failing address data collection); or, b) cause the BISTs within a specified proximity of the thermal sensor that has registered a specified upper temperature limit to enter a wait state, whereby the BIST pauses and waits until after the temperature has dropped by a pre-specified amount before continuing.
During a standby “idle” condition, dropping Vdd by a pre-specified amount will significantly reduce background leakage, allowing the temperature to be brought under control, without losing the valid BIST failing address data that has been collected up to this point. During the “idle” condition it may also be necessary to adjust the test conditions to help maintain temperature control upon resuming test, such as reducing the number of memories being tested, reducing the frequency of clocks during test or reducing the length of test.
The BIST test system and method according to the invention may be advantageously employed for system-on-chip (SOC) designs, ASICs including analog and digital circuitry, and memory circuits such as DRAM, register arrays, ROM and SRAM.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A depicts a plot 10 of the interaction between temperature and BIST test and particularly, the relationship between temperature vs. BIST test time;
FIG. 1B depicts a plot of temperature vs. BIST test time and the resulting BIST test interaction that ensures successful BIST testing according to the invention;
FIG. 2 is a circuit block diagram depicting the BIST and temperature sensor architecture according to the invention;
FIGS. 3A and 3B depict BIST test methodologies according to a first embodiment of the invention where test results of suspect circuits are ignored; and
FIGS. 4A-4C depict a BIST test methodologies according to a second embodiment of the invention wherein the testing of suspect circuits (e.g., suspect memories) is temporarily stopped.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the invention, a new BIST test approach is provided to avoid the risk of temperature limits being reached or exceeded, e.g., during the continuous and parallel self-testing of all electronic memories on a die. According to the approach, a BIST test system is provided that includes a temperature sensor for monitoring temperature of the chip under test and, the provision of feedback control for changing/modifying the BIST test activity according to the monitored temperature conditions.
FIG. 2 illustrates the novel BIST and Temperature Sensor architecture 100 to support temperature sensitive BIST for electronic devices (chip under test) according to the present invention. Representative of an on-chip BIST circuit contemplated for use in the present invention is the processor-based BIST described in U.S. Pat. No. 5,961,653 assigned to the International Business Machines, Inc., the whole contents and disclosure of which is incorporated by reference as if fully set forth herein. Further embodiments of a BIST circuit for use in the present invention is described in the reference to J. Barth, et al., entitled “A 500 MHz Multi-Banked Compilable DRAM Macro with Direct Write and Programmable Pipelining,” in IEEE Journal of Solid-State Circuits, vol. 40, pp. 213-222, January 2005, incorporated by reference herein, which describes BIST circuitry physically separated from a DRAM macro. This allows a single BIST engine to test multiple DRAM macros at operating speeds in excess of 500 Mhz at 1.05V and 105° C. The BIST contains sub-blocks including: instruction memory, clock generation circuitry, and pattern generation circuitry with additional functionality according to the invention as now described with reference to FIG. 2 .
As shown in FIG. 2 , the BIST and Temperature Sensor architecture 100 includes: an off-chip BIST tester 102 that is a processor device including an EXE output signal 104 for respectively initiating BIST test execution and providing a BIST test CLK (clock) signal 106 as is utilized by the BIST test devices implemented in the invention. As will be explained in further detail herein below, the tester 102 further receives an alert signal that is asserted by the on-chip BIST control device 120 to which the BIST tester 102 will respond by initiating or stopping BIST test execution. A BIST control circuit 120 is provided that receives EXE 104 and CLK 106 and includes a TEMP_IN input terminal for receiving a TEMP (temperature) output signal 160 of a logic circuit 155 connected for receiving outputs of a network of temperature sensor devices 150 a , . . . , 150 n . The BIST control circuit 120 is responsive to the temperature TEMP signal 160 for generating an ALERT_FLAG output signal 175 that is received by an ALERT_IN input terminal of the tester 102 . Further responsive to the value of the TEMP signal 160 received, the BIST control circuit 120 further generates a BEXE (begin execution) signal 124 and a PAUSE signal 126 for receipt by the BIST test circuit 130 providing BIST test I/O (TESTIO) signals 135 . The memory array 140 receives the TESTIO signals 135 and CLK signals 106 for performing BIST test operations.
As mentioned, there is provided one or more on-chip thermal sensor devices 150 a , . . . , 150 n that measure temperature at strategic locations of the chip under test, particularly, in proximity to the circuits being tested. Each temperature sensor is fabricated within the chip under test and may be user programmable to trigger once a temperature threshold has been crossed. Generally, such temperature sensors 150 a , . . . , 150 n include analog circuitry that generates a temperature value and an ADC (analog to digital converter) to produce a digital temperature value. The temperature sensor compares the digital temperature value to a user-programmed maximum value, or, a hard-coded threshold value and produce the ALERT_FLAG if the maximum value is exceeded. Other temperature sensors could use an analog comparison function (rather than digital) to produce the ALERT_FLAG if the maximum value is exceeded. Representative of a typical on-chip thermal sensor device is MAXIM 1464's On-Chip Temperature Sensor (Maxim Integrated Products, Inc.). The outputs of each sensor 150 a , . . . , 150 n is logically connected to a logic circuit 155 such as an n-input OR gate, or like equivalent. Each thermal sensor device 150 a , . . . , 150 n is used to determine which circuits, devices or memories (e.g., DRAM) are running or about to run at the high end of the allowed temperature range. Once this information is ascertained, as embodied by TEMP signal 160 , the BIST test methodology may be altered according to the methodologies described herein to ameliorate and/or correct the situation. For instance, once a thermal sensor device 150 a , . . . , 150 n determines that the operating temperature of a circuit meets or exceeds a predetermined threshold limit, the TEMP signal 160 will be asserted and will continue to be asserted as long as the temperature condition threshold is exceeded at that chip location.
FIG. 3A depicts a BIST test methodology 200 according to a first embodiment of the invention where test results of suspect circuits (e.g., memories) are ignored. As shown in FIG. 3A , the BIST test array executes at 205 until a TEMP signal 160 is asserted at 207 in response to the logic applied at the outputs of the one or more on-chip thermal sensor devices 150 a , . . . , 150 n . Upon receipt of the TEMP signal by BIST/CNTL circuit 120 ( FIG. 2 ), the process proceeds to step 209 which represent the step of BIST/CNTL circuit 120 asserting the ALERT_FLAG 175 to the tester device and further asserting a PAUSE signal 126 to the BIST. In response to receipt of the PAUSE signal 126 , BIST testing ceases collecting BIST test results as indicated at 212 until the BIST sub-pattern currently being executed completes as indicated at step 215 . At such time, the BIST suspends all operations as indicated at step 219 and the tester device 102 lowers the chip under test's operating power source voltage V DD as indicated at 222 . It should be understood that the amount that V DD may be decremented is dependent upon the chip technology implemented, the type of circuits being monitored, the physical size of the components, etc. In a further embodiment, alternatively or in addition to decreasing chip under test's operating power source voltage, other test circuit adjustments may be made to assist in lowering temperature: for example increasing the cooling provided by the tester or reducing or stopping clock switching. Then, after decreasing the chip under test's operating voltage V DD and/or performing other test circuit adjustments at step 222 , the Tester circuit monitors TEMP signal at 225 until the TEMP signal de-asserts indicating a return to the normal starting temperature as experienced during previous tests, i.e., a reduction to a more normal BIST operating temperature condition. Until the temperature threshold condition returns to normal as indicated at 230 , the Tester will wait at step 225 . Once the TEMP signal 160 is de-asserted, the process proceeds to step 235 where the Tester adjusts the test setup by reducing the clock frequency or the number of circuits under test or the test pattern length. Then, as indicated at step 240 , in response to the TEMP signal 160 being de-asserted, the BIST/CNTL circuit 120 ( FIG. 2 ) de-asserts the ALERT_FLAG to the Tester 102 and the PAUSE signal is de-asserted to the BIST tester 130 . As indicated at step 245 , the BIST tester 130 returns V DD to the starting test condition voltage levels. Then, in response to de-asserting the ALERT_FLAG 175 to the Tester 102 ( FIG. 2 ) the Tester 102 asserts the EXE signal 104 to the BIST/CNTL circuit 120 as indicated at step 250 in FIG. 3A . Continuing to step 260 , in response to receipt of the EXE signal 104 , the BIST/CNTL circuit 120 asserts the BEXE signal 124 to the BIST 130 and, at 270 , the BIST re-starts applying sub-patterns for the BIST test array and the process returns to step 205 . Thus, FIG. 3A exemplifies a BIST flow using temperature monitors to maintain consistent test conditions whereby test results are ignored and test array sub-patterns are re-started after temperature correction.
FIG. 3B depicts a BIST test methodology 200 ′ which is a variant of the test methodology applied as described with respect to FIG. 3A . According to the variant test methodology depicted in FIG. 3B , every step is identical as in corresponding FIG. 3A , except for step 270 ′ which depicts the step of starting the next sub-pattern after the sub-pattern completed at step 215 prior to correcting for the temperature condition. Thus in the embodiment depicted in FIG. 3B , the test results of suspect circuits (e.g., memories) are ignored and the sub-patterns skipped after temperature correction.
Thus, it is seen that in the embodiment of the invention directed to ignoring the BIST results ( FIGS. 3A , 3 B), once the test has completed, the tester has the option of continuing test, either without or while continuing with, test adjustments, i.e., adjust (lower) Vdd (reduce DC power), reduce length of test, reduce AC power by lowering clock frequency, and reduce the number of memories/circuits tested, etc., followed by proceeding to the next sub-pattern ( FIG. 3B ) or, re-running the beginning of the previous sub-pattern ( FIG. 3A ).
FIG. 4A depicts a BIST test methodology 300 according to a second embodiment of the invention wherein the testing of suspect circuits (e.g., suspect memories) is temporarily stopped. As shown in FIG. 4A , the BIST test array executes at 305 until a TEMP signal 160 is asserted at 307 in response to the logic applied at the outputs of the one or more on-chip thermal sensor devices 150 a , . . . , 150 n . Upon receipt of the TEMP signal by BIST/CNTL circuit 120 ( FIG. 2 ), the process proceeds to step 309 which represent the step of BIST/CNTL circuit 120 asserting the ALERT_FLAG 175 to the tester device and further asserting a PAUSE signal 126 to the BIST. In response to receipt of the PAUSE signal 126 , the BIST stops testing the array as indicated at step 312 and returns to the sub-pattern at the initial (start) state at 315 . After returning to the sub-pattern at the initial (start) state at 315 , the BIST suspends all operations as indicated at step 319 and the tester device 102 lowers the chip under test's operating power source voltage V DD as indicated at 322 . As mentioned hereinabove, the amount that V DD may be decremented is dependent upon the chip technology implemented, the type of circuits being monitored, the physical size of the components, etc. In a further embodiment, alternatively or in addition to decreasing chip under test's operating power source voltage, other test circuit adjustments may be made to assist in lowering temperature: for example increasing the cooling provided by the tester or reducing or stopping clock switching. Then, after decreasing the chip under test's power supply voltage V DD and/or performing other test circuit adjustment at step 322 , the Tester circuit monitors TEMP signal at 325 until the TEMP signal de-asserts indicating a return to the normal starting temperature as experienced during previous tests, i.e., a reduction to a more normal BIST operating temperature condition. Until the temperature threshold condition returns to normal as indicated at 330 , the Tester will wait at step 325 . Thus, by causing BIST to enter a wait state, the switching activity of the suspect memories are temporarily disabled. Once the TEMP signal 160 is de-asserted, the process proceeds to step 335 where the Tester adjusts the test setup by reducing the clock frequency or the number of circuits under test or the test pattern length. Then, as indicated at step 340 , in response to the TEMP signal 160 being de-asserted, the BIST/CNTL circuit 120 ( FIG. 2 ) de-asserts the ALERT_FLAG to the Tester 102 and the PAUSE signal is de-asserted to the BIST tester 130 . As indicated at step 345 , the BIST tester 130 returns V DD to the starting test condition voltage levels. Then, in response to de-asserting the ALERT_FLAG 175 to the Tester 102 ( FIG. 2 ) the Tester 102 asserts the EXE signal 104 to the BIST/CNTL circuit 120 as indicated at step 350 in FIG. 4A . Continuing to step 360 , in response to receipt of the EXE signal 104 , the BIST/CNTL circuit 120 asserts the BEXE signal 124 to the BIST 130 where the BIST re-starts applying sub-patterns for the BIST test array as indicated by the return to step 305 . Thus, FIG. 4A exemplifies a BIST flow using temperature monitors to maintain consistent test conditions whereby test array sub-patterns are re-started after temperature correction.
FIG. 4B depicts a BIST test methodology 300 ′ which is a variant of the test methodology applied as described with respect to FIG. 4A and applicable to the testing of SRAM and DRAM types of memory. According to the variant test methodology depicted in FIG. 4B , every step is identical as in corresponding FIG. 4A , except for steps 315 and 319 of FIG. 4A which are omitted according to the method depicted in FIG. 4B and replaced instead with a step 320 directed to the step of suspending SRAM BIST testing, suspending DRAM BIST testing, and, issuing a memory refresh signal to the DRAM under test. After performing step 320 , the next steps include: decreasing the chip under test's operating voltage V DD and/or performing other test circuit adjustment at step 322 , monitoring by the Tester circuit the TEMP signal at 325 until the TEMP signal de-asserts at step 325 indicating a return to the normal starting temperature as experienced during previous tests, i.e., a reduction to more normal BIST operating temperature condition. Until the temperature threshold condition returns to normal as indicated at 330 , the Tester will wait at step 325 . Once the TEMP signal 160 is de-asserted, the process proceeds to step 335 where the Tester adjusts the test setup by reducing the clock frequency or the number of circuits under test or the test pattern length. Then, as indicated at step 340 , in response to the TEMP signal 160 being de-asserted, the BIST/CNTL circuit 120 ( FIG. 2 ) de-asserts the ALERT_FLAG to the Tester 102 and the PAUSE signal is de-asserted to the BIST tester 130 . As indicated at step 345 , the BIST tester 130 returns V DD to the starting test condition voltage levels. Then, in response to de-asserting the ALERT_FLAG 175 to the Tester 102 ( FIG. 2 ) the Tester 102 asserts the EXE signal 104 to the BIST/CNTL circuit 120 as indicated at step 350 in FIG. 4B and, continuing to step 360 , in response to receipt of the EXE signal 104 , the BIST/CNTL circuit 120 asserts the BEXE signal 124 to the BIST 130 where the BIST re-starts applying sub-patterns for the BIST test array as indicated by the return to step 305 . Thus, FIG. 4B exemplifies a BIST flow using temperature monitors to maintain consistent test conditions whereby upon detection of a temperature condition failure, both SRAM and DRAM BIST testing is suspended and, a memory refresh signal is applied to the DRAM under test, and, upon returning to normal test temperature conditions, test array sub-patterns are continued from where sub-pattern was interrupted.
FIG. 4C depicts a BIST test methodology 300 ″ which is a variant of the test methodology applied as described with respect to FIG. 4A . According to the variant test methodology depicted in FIG. 4C , every step is identical as in corresponding FIG. 4A , except for step 315 of FIG. 4A which is omitted according to the method depicted in FIG. 4B and replaced instead with a step 316 directed to the step of skipping to the next BIST test sub-pattern start state. After performing step 316 , the next steps include: suspending BIST test operations at 319 , decreasing the chip under test's supply voltage V DD and/or performing other test circuit adjustment at step 322 , monitoring by the Tester circuit the TEMP signal at 325 until the TEMP signal de-asserts at step 325 indicating a return to the normal starting temperature as experienced during previous tests, i.e., a reduction to more normal BIST operating temperature condition. Until the temperature threshold condition returns to normal as indicated at 330 , the Tester will wait at step 325 . Once the TEMP signal 160 is de-asserted, the process proceeds to step 335 where the Tester adjusts the test setup by reducing the clock frequency or the number of circuits under test or the test pattern length. Then, as indicated at step 340 , in response to the TEMP signal 160 being de-asserted, the BIST/CNTL circuit 120 ( FIG. 2 ) de-asserts the ALERT_FLAG to the Tester 102 and the PAUSE signal is de-asserted to the BIST tester 130 . As indicated at step 345 , the BIST tester 130 returns VDD to the starting test condition voltage levels. Then, in response to de-asserting the ALERT_FLAG 175 to the Tester 102 ( FIG. 2 ) the Tester 102 asserts the EXE signal 104 to the BIST/CNTL circuit 120 as indicated at step 350 in FIG. 4C and, continuing to step 360 , in response to receipt of the EXE signal 104 , the BIST/CNTL circuit 120 asserts the BEXE signal 124 to the BIST 130 where the BIST re-starts applying sub-patterns for the BIST test array as indicated by the return to step 305 . Thus, FIG. 4C exemplifies a BIST flow using temperature monitors to maintain consistent test conditions whereby upon detection of a temperature condition failure, the method advances to the next BIST sub-pattern start state, which next BIST test sub-pattern is initiated upon returning to normal test temperature conditions.
Thus, it is seen that in the embodiment of the invention directed to temporarily stopping testing of suspect circuits under test (e.g., static and/or dynamic memories) ( FIG. 4A-4C ), the method for resuming BIST test after the wait state can take one of three forms—the particular sub pattern can be resumed or continued (a valid option for SRAM's and other static memories or a DRAM with automatic refresh) ( FIG. 4B ), the sub pattern can be restarted ( FIG. 4A ), or the sub pattern can be skipped entirely ( FIG. 4C ).
FIG. 1B depicts a plot 20 of the interaction between temperature and BIST test and particularly, the relationship between temperature vs. BIST test time in accordance with the various embodiments of the present invention. As shown in FIG. 1B , after detection of BIST failure due to exceeding a operating temperature specification at 22 (and subsequent assertion of the ALERT_FLAG), the plot 20 shows the decrease in temperature condition 25 as a result of modifying the test conditions (e.g., stopping BIST test, lowering VDD, clock frequency, and/or other adjustments as described herein) and, the plot 29 depicting the resumption of valid BIST testing 29 after the ALERT_FLAG is de-asserted and the BIST testing condition returns to normal (i.e., test setup adjusts, for example, by returning Vdd to normal). As shown in FIG. 1B , a BIST test thermal runaway condition is completely avoided.
The invention has been described herein with reference to particular exemplary embodiments. Certain alterations and modifications may be apparent to those skilled in the art, without departing from the scope of the invention. The exemplary embodiments are meant to be illustrative, not limiting of the scope of the invention.
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A Built-In-Self-Test (BIST) state machine providing BIST testing operations associated with a thermal sensor device(s) located in proximity to the circuit(s) to which BIST testing operations are applied. The thermal sensor device compares the current temperature value sensed to a predetermined temperature threshold and determines whether the predetermined threshold is exceeded. A BIST control element suspends the BIST testing operation in response to meeting or exceeding said predetermined temperature threshold, and initiates resumption of BIST testing operations when the current temperature value normalizes or is reduced. A BIST testing methodology implements steps for mitigating the exceeded temperature threshold condition in response to determining that the predetermined temperature threshold is met or exceeded. These steps include one of: ignoring the BIST results of the suspect circuit(s), or by causing the BIST state machine to enter a wait state and adjusting operating parameters of the suspect circuits while in the wait state.
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TECHNICAL FIELD
The present invention relates to limitation of temperature variations in flowing gases in a combustion plant in which heat transfer surfaces are arranged in the gas paths to limit the temperature of the gas which is supplied to a combustor located in the plant and of the flue gases emitted from the plant. The invention is especially valuable in a power plant with combustion in a pressurized fluidized bed, a Pressurized Fluidized Bed Combustion (PFBC)--plant, in which it permits limitation of temperature variations in pressurized air supplied to the combustor and flue gases emitted from the plant. This means that power output or efficiency remains essentially unaffected by variations in ambient temperature and compression ratios.
BACKGROUND OF THE INVENTION
During combustion in a fluidized bed, the fluidized bed is supplied with air for fluidization of the bed material and for combustion of fuel supplied to the fluidized bed. If the fluidized bed is part of a plant for combustion in a pressurized fluidized bed, a PFBC plant, the fluidized bed contained within a bed vessel is enclosed in a pressure vessel and the air supplied to the fluidized bed is pressurized, for example in a compressor driven by a gas turbine.
The mass flow of pressurized air supplied to a PFBC plant is controlled within an interval of 40-105% of nominal flow. The pressurization is normally carried out in a gas turbine-driven compressor. From the point of view of capital cost, high compression ratios are desirable A gas turbine-driven compressor provides different possibilities of controlling the mass flow, depending on the type of gas turbine. A single-shaft unit may control the mass flow by varying the adjustment of compressor guide vanes and inlet valves, and, in addition, compressed air may be recirculated through the compressor. Moreover, in a multi-shaft unit, adjustable turbine guide vanes and nozzles as well as variable rotor speed are utilized.
The temperature of the air supplied from the compressor via the pressure vessel to the fluidized bed must be limited, both when the air is used for cooling of pressure vessel, bed vessel, cyclones and other supporting components arranged in the pressure vessel, and when temperature variations, caused by compression ratios and ambient temperature, in air supplied to the fluidized bed affect the output power from the plant and the efficiency of the plant.
The temperature of air supplied to the pressure vessel is not limited in normal PFBC plants, and thus there is no equalization of the temperature variations which occur in the pressurized air. Temperature variations occur as a consequence of variations in the ambient temperature and varying compression ratios and are compensated for in a normal PFBC plant by a change in the output power from the plant and in the efficiency of the plant.
The residual heat in flue gases emitted from a combustion plant is delivered to flue gas economizers, which are arranged in the flue gas paths.
SUMMARY OF THE INVENTION
The influence of variations in the ambient temperature, compression ratios in air pressurized in the compressor, and the like, which in a plant for combustion in a pressurized fluidized bed, a PFBC--plant, is reflected in the output power from the plant and in the efficiency of the plant, is essentially eliminated when temperature variations in incoming Combustion air are limited according to the present invention.
The plant comprises a combustor in the form of a pressurized fluidized bed, air paths in which air supplied to the fluidized bed is pressurized, flue gas paths in which energy contained in flue gases emitted from the plant is partially extracted with a gas turbine arranged in the flue gas paths, and a feedwater/steam system comprising heat transfer surfaces arranged in the air and flue gas paths.
According to the present invention, the temperature variations of pressurized air supplied to the fluidized bed are limited by means of heat transfer surfaces, preferably in the form of a heat exchanger, arranged in the air paths.
According to a preferred embodiment of the present invention, the temperature of flue gases discharged from the plant is simultaneously limited with heat transfer surfaces, arranged in the flue gas paths, in the form of cold and hot flue gas economizers. In addition, heat transfer surfaces arranged in the hot and cold sections of the flue gas paths and in the air paths are interconnted in the high temperature section of the feedwater/steam system of the combustion plant. By this interconnection and by the arrangement of control valves adjacent to the heat transfer surfaces, for control and distribution of the heat work in and between the heat transfer surfaces, the temperature of air supplied to the pressure vessel may be limited and maintained independent of temperature variations of air pressurized in the compressor while at the same time the flue gas temperature is limited.
The heat work in the heat transfer surfaces may be controlled from outside with temperature sensors, for example thermocouples, measuring temperatures of air and flue gas, respectively. Measured temperatures are compared, in conventional temperature regulators, with a desired value and the deviation gives a control signal out from the temperature regulator to the control valves arranged adjacent to the heat transfer surfaces. Based on the received control signal, the heat work in the heat-transfer surfaces is controlled.
Thus, according to the present invention, the necessary limitation of the temperature variations of air supplied to the fluidized bed is obtained, so that the output power from the combustion plant or the efficiency of the plant remains unaffected by ambient temperature and compression ratios while at the same time heat absorbed in the heat transfer surfaces is utilized in the feedwater/steam system of the plant
In addition, during start-up and shutdown of a PFBC plant with control of air and flue gas temperatures according to the present invention, possibilities are provided of reducing the heating and cooling times.
The heating time during start-up can be reduced and hence the corrosion, caused by flue gas condensate in the gas paths, be reduced by the heat transfer surfaces upon start-up being traversed by steam from an external source, for example from an existing auxiliary boiler intended to supply the plant with de-aired water.
The cooling times can be reduced by the heat transfer surfaces, upon shutdown, being traversed by water, for example by being connected to a condenser circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will be explained in greater detail with reference to functional and schematic flow diagrams, wherein:
FIG. 1 illustrates a system for the limitation, in a combustion plant with gas turbine-driven pressurization of air supplied to the combustor, of temperature variations of pressurized air supplied to the fluidized bed in accordance with the present invention;
FIG. 2 shows schematically the parts of the air and flue gas paths, the feedwater/steam system and other components of the plant, which are necessary for the present invention;
FIG. 3 illustrates alternative solutions to the supply of the pressurized air to the pressure vessel;
FIGS. 4 and 5 show respectively, design and connection of the feedwater/steam system to an auxiliary boiler during start-up and to a condenser circuit during cooling; and
FIG. 6 shows an alternative connection which under special circumstances, especially when only part of the pressurized air passes the heat transfer surfaces in the air paths, provides increased efficiency.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A system for limitation of temperature variations of pressurized air supplied to the fluidized bed according to the present invention is schematically illustrated in FIG. 1. The air is supplied to a combustor 10, in the form of a fluidized bed, through air paths 1, flue gases formed during the combustion are discharged through flue gas paths 2 and heat is extracted from the plant and utilized through a feedwater/steam system 3.
In a power plant with combustion in a pressurized fluidized bed, a Pressurized Fluidized Bed Combustion PFBC plant, the combustion takes place in a fluidized bed 10 contained within a bed vessel 12 enclosed in a pressure vessel 11. Air is introduced into the plant at A, is pressurized in a compressor 13, the temperature being raised to a temperature which depends on the prevailing compression ratio and the ambient temperature. The pressurized air is used for fluidization of the fluidized bed 10 and for combustion of fuel supplied to the fluidized bed 10.
The flue gases formed during the combustion pass through a gas turbine 14 arranged in the flue gas paths 2 of the plant, in which at least part of the energy contained in the flue gases is extracted. The compessor 13 is suitably driven by the gas turbine 14. In addition, to increase the efficiency of the plant, the residual heat is extracted from the flue gases in heat transfer surfaces 15, 16, arranged in both the hot and cold sections of the flue gas paths 2, for example flue gas economizers, designated as the hot flue gas economizer 15 and the cold flue gas economizer 16, respectively, before the flue gases are discharged from the plant at B.
In order not to subject the pressure vessel 11 or other components, arranged in the pressure vessel 11 or the bed vessel 12, to high temperatures, these are cooled by supplied pressurized air. To limit the temperature of the supplied pressurized air and to correct for temperature variations, caused by ambient temperature and compression ratios, the pressurized air passes through heat transfer surfaces 17, for example a heat exchanger, arranged in the air paths 1 beween the compressor 13 and the pressure vessel 11. The temperature variations, which are caused by fluctuating ambient temperature or compression ratios, are corrected according to the present invention in the heat exchanger 17, which means that the efficiency of the plant is not affected by these temperature fluctuations while at the same time energy extracted in the heat exchanger 17 is utilized in the feedwater/steam system 3 of the plant.
The temperature of the pressurized air is measured in conventional manner, for example by thermocouples 50, in the air paths downstream of the compressor 13. The measured temperature is compared with the desired temperature in a conventional temperature regulator 51. The deviation gives rise to an output signal, control signal supplied, to a control valve 18 by signal lines 52. The control valve 18 controls the heat work in the heat exchanger 17 by varying the flow of feedwater/steam through the heat exchanger 17, for example via the by-pass duct 19.
Variations in the feedwater/steam temperature arising downstream of the heat exchanger 17 are measured in conventional manner for example, by thermocouples 53 and corrected when the hot flue gases, in the hot flue gas economizer 15, pass through the feedwater/steam system 3 resulting in the flue gas temperature downstream of the hot flue gas economizer 15 being influenced.
The influence on the flue gas temperature downstream of the hot flue gas economizer 15 is measured in conventional manner for example, by the thermocouples 54 and, after treatment in a conventional temperature regulator 55, supplies a control signal to a control valve 20 by signal line 56. The control valve 20 then controls the heat work in the cold flue gas economizer 16, for example by distributing the feedwater/steam flow between the two branches 21 of the feedwater/steam circuit 3, comprising the cold flue gas economizer 16, and 22, comprising heat transfer surfaces 23 for heating another medium, for example high pressure feedwater. Where necessary or if the branch 22 is missing, feedwater/steam is conducted, at least partially, past the cold flue gas economizer 16, preferably via a by-pass duct 24.
By integration of the heat transfer surfaces 15, 16, 17, arranged in the air paths 1 and the flue gas paths 2, into the feedwater/steam system 3 of the power plant, the invention provides a limitation of the temperature of compressed air supplied to the pressure vessel and the bed vessel while at the same time temperature variations in this air are essentially eliminated. This means that the efficiency and power output of the plant remain essentially unaffected by variations in ambient temperature and compression ratios.
Energy extracted from air and flue gases is transferred to the feedwater/steam system 3 of the power plant. The heat transfer surfaces 15, 16, 17, which are necessary according to the present invention, are connected at the point C, for example to a feedwater tank, and at the point D, for example to a boiler arranged in the fluidized bed 10, to the high temperature section of the feedwater/steam system 3. In certain situations, for example during start-up and shutdown of the power plant, the heat transfer surfaces may be connected to a circuit by being interconnected at C and D. If the circuit is then provided with steam or cold water, heating and cooling, respectively, of air paths 1 and flue gas paths 2 may be obtained.
FIG. 2 schematically shows how the heat transfer surfaces, which are necessary for the present invention, are arranged in the air paths 1, flue gas paths 2 and feedwater/steam system 3 of the power plant.
In a PFBC plant pressurized air is supplied to a fluidized bed 10 enclosed in a pressure vessel 11. The air is supplied to the fluidized bed 10 for fluidization of the bed material and for combustion of fuel supplied to the fluidized bed 10. The air, which is admitted from the environment via at least one controllable throttle valve 25, is pressurized in a compressor 13, suitably driven by a gas turbine 14 arranged in the flue gas paths. The gas turbine 14 also drives a generator 26. The gas turbine 14 and the compressor 13 are often integrated into one unit and may be of an arbitrary type with a variable number of shafts. The figures show no intermediate cooling of the pressurized air, which occurs in multi-shaft units.
The mass flow of pressurized air to the pressure vessel 11 in a PFBC plant is controlled within an interval of 40-105% of nominal flow. The mass flow from the compressor 13 may, depending on the type of gas turbine/compressor unit 14/13, be controlled in different ways A single-shaft gas turbine/compressor unit 14/13, as indicated in FIG. 2, may be controlled by adjusting the throttle valve 25, the compressor guide vanes 27 and via a recirculation circuit 28 for pressurized air. For a multi-shaft gas turbine/compressor unit, the possibilities of varying turbine guide vanes, turbine nozzles and rotor speed are added.
The temperature of the pressurized air usually amounts to 350-450° C., depending on compression ratio and ambient temperature. Before the pressurized air is supplied to the pressure vessel 11, it is cooled to a temperature suitable for the pressure vessel 11 and the parts enclosed in the pressure vessel 11, usually 200-300° C., in at least one heat exchanger 17 arranged in the air paths. According to the invention, the heat exchanger 17 is arranged in the high temperature section of the feedwater/steam system 3, up-stream of a flue gas economizer 15 arranged in the hot part of the flue gas paths 2.
To maintain the temperature of pressurized air supplied to the pressure vessel 11 essentially independent of compression ratio and ambient temperature, the feedwater/steam flow through the heat exchanger 17 is controlled in a control valve 18. The control valve 18 distributes the feedwater/steam flow, between the heat exchanger 17 and a by-pass duct 19, based on the deviation between desired and measured temperature of the pressurized air. With the by-pass duct 19, the feedwater/steam flow is adapted to the measured temperature of the pressurized air. Without the by-pass duct 19, there would be a risk of the feedwater temperature and hence the temperature of air supplied to the pressure vessel 11 dropping towards the ambient temperature.
The control in the heat exchanger 17 gives rise to variations of the feedwater/steam temperature downstream of the heat exchanger 17, which are essentially eliminated in at least one flue gas economizer 15 arranged in the hot section of the flue gas paths 2, resulting in the flue gas temperature downstream of the hot flue gas economizer 15 being affected. The influence on the flue gas temperature is essentially eliminated in at least one flue gas economizer 16 arranged in the cold section of the flue gas paths 2 by adapting the feedwater/steam flow therethrough to correct, in conventional manner, any deviation, measured in the flue gas paths 2 downstream of the hot flue gas economizer 15, of the flue gas temperature relative to the desired flue gas temperature.
The control of the feedwater/steam flow through the cold flue gas economizer is performed with the control valve 20 which controls the distribution between the two parallel branches 21 and 22 in the feedwater/steam system 3, including the cold flue gas economizer 16 and the heat exchanger 23, respectively, connected for heating of another medium, for example high-pressure feedwater.
With heat transfer surfaces comprising at least one heat exchanger 17 arranged in the air paths, in which the temperature of air supplied to the pressure vessel 11 and the fluidized bed 10 is limited and temperature variations in the air are essentially eliminated, at least one flue gas economizer 15 arranged in the hot section of the flue gas paths, in which simultaneously with the flue gas temperature being reduced temperature variations of the feedwater/steam are essentially eliminated by allowing the flue gas temperature downstream of the hot flue gas economizer 15 to vary, at least one flue gas economizer 16 arranged in the cold section of the flue gas paths, in which variations of the flue gas temperature are essentially eliminated, and the by-pass ducts 19 and 24 for control of the heat work in the heat exchanger 17 and the cold flue gas economizer 16, respectively, according to the present invention a limitation of the temperature of air supplied to the pressure vessel 11 and of flue gases emitted from the PFBC plant is obtained while at the same time the influence from ambient temperature and compression ratios on the efficiency or the power output of the plant is essentially eliminated.
The heat exchanger 17 can be dimensioned for two cases:
I. Maximum heat work for the operation at the maximum air temperature and full air flow;
II. Only part of the heat work of the operation, which means that part of the pressurized air is conducted past the heat exchanger 17 in a pipe 29 direct to the air inlet to the fluidized bed 10.
The two cases are illustrated in FIG. 3.
Case I corresponds well with the previous description whereas in case II only part of the air quantity from the compressor 13 passes through the heat exchanger 17. The remaining air quantity is supplied, via a pipe 29, to the cooled air flow near the air inlet to the fluidized bed 10. The distribution of air is controlled such that the heat work in the heat exchanger 17 is maintained constant, that is, an increased ambient temperature entails an increased flow via the pipe 29. Case II means that the temperature of vital components such as pressure vessel 11, bed vessel 12 and cyclones 30 may be limited with a heat exchanger 17 of limited power.
During start-up of a PFBC plant, air paths 1 and flue gas paths 2 are preheated according to FIG. 4. Preheating is usually performed by burning fossil fuels in the air paths 1 upstream of the fluidized bed 10. To avoid corrosion connected with flue gas condensate, components included in the air paths 1 and the flue gas paths 2 must be preheated, for example with dry hot air, to a temperature exceeding the dew point of the flue gases which occur during the preheating. This first phase of the preheating is achieved in a favorable way by connecting the heat transfer surfaces,--the heat exchanger 17, the hot flue gas economizer 15 and the cold flue gas economizer 16,--, which according to the invention are interconnected and arranged in the air paths 1 and the flue gas paths 2, to an external source (not shown) with hot medium, for example a boiler present in the plant and intended to supply the plant with de-aired water during the start-up stage.
During the starting period the gas turbine 14 is driven by a starting device 31, which may consist of a frequency convertor which permits the gas turbine 14 to be run as a synchronous motor, but may also consist of a motor connected to any of the shafts of the gas turbine 14, or other starting equipment for gas turbines The air is heated in the heat exchanger 17, the hot flue gas economizer 15 and the cold flue gas economizer 16 and transfers the heat to walls and other components in the air paths 1 and the flue gas paths 2. If the bed vessel 12 is empty and the valve 32 shown in FIGS. 2 and 3 is open, the air will flow through the pressure vessel 11 and the bed vessel 12 thus heating these.
The heat exchanger 17, the hot flue gas economizer 15 and the cold flue gas economizer 16 are connected in a starting circuit, which is illustrated in FIG. 4. As before, the heat transfer surfaces 15, 16, 17 are connected to the high temperature section of the feedwater/steam system 3 of the plant, for example at an existing feedwater tank 33. The feedwater tank 33 is provided with steam, for example from an auxiliary boiler (not shown) present in the plant. The feedwater/steam circulates during the starting stage from the feedwater tank 33 through the two flue gas economizers 15 and 16 and the heat exchanger 17 and back to the feed-water tank 33 via the open return pipe 34.
During shutdown of the plant, the cooling period can be shortened by utilizing the heat transfer surfaces 15, 16 and 17 arranged in the air paths 1 and the flue gas paths 2 according to the invention. This makes the plant more rapidly available for, for example, maintenance work. The heat transfer surfaces 15, 16 and 17 are connected (see FIG. 5) to an external source with a coolant, for example a condenser circuit located in the plant for hot water production, via a valve 35. This causes the heat transfer surfaces 15, 16 and 17 arranged in the air paths 1 and the flue gas paths 2 to be traversed by a cold medium and the temperature in air and flue gas paths to be rapidly reduced.
An alternative solution of the arrangement of the heat exchanger 17 in the system, in relation to the hot flue gas economizer 15, is shown in FIG. 6. The heat exchanger 17 is connected in parallel with the hot flue gas economizer 15, which reduces the temperature difference between air and feedwater/steam in the heat exchanger 17. Especially when dimensioning the heat exchanger 17 in accordance with the above case II, this solution may further increase the efficiency of the plant.
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A method for cooling and eliminating temperature variations in a power plant for combustion of a fuel in a pressurized fluidized bed includes pressuring air in a compressor and supplying the pressurized air to the pressurized fluidized bed through air paths after the pressurized air is cooled and temperature variations in the pressurized air are substantially eliminated prior to supplying the pressurized air into the pressurized fluidized bed in at least one transfer surface provided in the air paths. The at least one heat transfer surface is connected with a high temperature section of a feedwater/steam section for utilizing energy extracted in the heat transfer surface and the temperature variations of the pressurized air supplied to the pressurized fluidized bed are eliminated by controlling the feedwater/steam flow through the heat transfer surface based on the deviations between a desired temperature of the air to be delivered to the fluidized bed and a measured temperature of the pressurized air from the compressor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/713,807, filed on Nov. 14, 2003, which claims priority from U.S. Provisional Application No. 60/469,187, filed on May 12, 2003. U.S. patent application Ser. No. 10/713,807 and U.S. Provisional Application No. 60/469,187 are both incorporated herein by reference in their entirety.
TECHNICAL FIELD
The invention relates to video data and more specifically to methods and systems of coding, decoding, compressing, and transmitting video data in as efficient a manner as possible.
BACKGROUND
The transmission of data is usually constrained by bandwidth and throughput limitations. One cannot send or receive an infinite amount of information in an infinitesimal amount of time. In order to maximize the amount and quality of information being transmitted, in some cases the information is compressed or coded for transmission and uncompressed or decoded upon reception.
One area in which data compression is essential is in the transmission of video data. Ordinary text, unless voluminous, is easily and quickly transmitted. However, video data can include aspects of color, brightness, and often stereo audio information. A large amount of data is required to define even short video clips. The transmission and coding of such data must be as efficient as possible, i.e., it must require as little information as possible to be transmitted.
Video compression is a subset of the general technique of data compression, whereby a signal is squeezed or compressed into a smaller set of numbers. These numbers will then take up less space on a hard drive, or take less time to transmit over a network. Before the numbers are used again, a decompression algorithm is applied to expand the series of numbers to its original (or at least a similar) form.
Video compression utilizes the fact that the signal is known to originate as digitized video, in order to increase the compression ratio, or the amount of squeezing that can be applied to the series of numbers to be stored or transmitted. Significant compression of video and audio are considered lossy algorithms because they discard or lose some portion of the original information; the reconstructed number series does not exactly match the original. This is acceptable because the precision with which we view video and audio, compared to the resolution of the digitization process, is not perfect. While the video signal may become slightly distorted, it is still recognizable. The degree to which a compression algorithm faithfully reproduces the original signal with minimum distortion or loss is a measure of the success of the algorithm.
There are a number of good reasons to compress video and audio signals, including technical issues and cost of equipment. one overriding issue is the cost of transmitting data. As the Internet matures into the de facto data transport platform for the 21st century, analog media such as videotape, film, and broadcast will be supplanted by a digital media infrastructure built on the Internet and Internet-related technologies. This digital infrastructure will allow data to be transferred between any two computing machines on the planet, if so desired. However, the speed at which this data can be sent will depend on a number of factors. In the limiting case, copper wires laid down over a century ago and intended for analog voice communications are used with modem technology (modem stands for Modulation/DEModulation) to transmit data at speeds as low as 9600 bits per second. Similar speeds are used to carry voice over wireless networks such as cellular. Recently, cable modem, DSL, and satellite technologies have brought six-figure data rates (100,000 to 1 million bits/second) to home users. For high-end applications, optical fiber enables data rates into the gigabit range (billions of bits per second) and beyond.
Whatever the data rate available for a given application, transmitting data costs money. At the present time, the cost of sending one megabyte (8 million bits) over the Internet usually costs anywhere from 5 cents at low volume, down to as low as one cent at extremely high volume (this figure does not include the cost at the receiving end). Therefore, the cost of transporting a megabyte of data from one place to another is always more than a penny.
Much work has been done in the field of video data compression. Some of the features of video codecs in existence include Discrete Cosine Transform compression, entropy coding, and differential coding of motion vectors. Prior codecs also utilize reference frames so that if a data packet is lost or corrupted, the data can be retrieved by referring to a reference frame. All of these features and difficulties therewith will be discussed in greater detail below.
In DCT (Discrete Cosine Transform) based video compression systems, an 8 by 8 block of pixel or prediction error signal data is transformed into a set of 64 frequency coefficients (a DC value and 63 AC values), which are then quantized and converted into a set of tokens.
Typically the higher frequency AC coefficients are smaller in magnitude and hence less likely to be non zero (i.e., more likely to be zero) following quantization. Consequently, prior to tokenization, the coefficients are often arranged in ascending order starting with the lowest frequency coefficient (the DC value) and finishing with the highest frequency AC coefficient. This scan order, sometimes referred to as “zig-zag order”, tends to group together the non-zero values at the start and the zero values into runs at the end and by so doing facilitates more efficient compression.
However, this fixed scan order is seldom optimal. For example, when encoding interlaced video material, certain high frequency coefficients are much more prominent. This fact is reflected in the prior art where there are examples of codecs (for example MPEG-2), that mandate an alternative scan order for use when coding interlaced video.
When optimizing a codec for a specific hardware device, it is important to make sure that full use is made of any facilities that the device may offer for performing multiple tasks in parallel and to limit the extent to which individual parts of the decode process become bottlenecks.
The instant invention's bitstream, in common with most other video codecs, can broadly speaking be described as comprising entropy coded tokens that can be divided into two main categories: predictor or P tokens and prediction error or E tokens. P tokens are tokens describing the method or mode used to code a block or region of an image and tokens describing motion between one frame and another. E tokens are used to code any residual error that results from an imperfect prediction.
Entropy coding is a process whereby the representation of a specific P or E token in the bitstream is optimized according to the frequency of that token in the bitstream or the likelihood that it will occur at a particular position. For example, a token that occurs very frequently will be represented using a smaller number of bits than a token that occurs infrequently.
Two of the most common entropy coding techniques are Huffman Coding and arithmetic coding. In Huffman coding each token is represented by a variable length pattern of bits (or a code). Arithmetic coding is a more computationally complex technique but it removes the restriction of using a whole number of bits for each token. Using an arithmetic coder, it is perfectly possible to code a very common token at an average cost of 2% of a bit.
Many multimedia devices have a co-processor unit that is well suited to the task of entropy coding and a more versatile main processor. Consequently, for the purpose of parallelization, the process of encoding or decoding a bitstream is often divided into entropy related tasks and non entropy related tasks. However, for a given video clip, as the data rate increases, the number of tokens to encode/decode rises sharply and entropy coding may become a bottleneck.
With a conventional bitstream it is very difficult to re-distribute the computational load of entropy coding to eliminate this bottleneck. In particular, on the decode side, the tokens must normally be decoded one at a time and in the order in which they were encoded. It is also extremely difficult to mix methods or entropy encoding (for example Huffman and arithmetic coding) other than at the frame level.
By convention, most modern video codecs code the (x, y) components of a motion vector, using a differential coding scheme. That is, each vector is coded relative to the previous vector. For example, consider two vectors (7,3) and (8,4). In this case the second vector would be encoded as (1,1), that is (7+1, 3+1).
This scheme works well if most blocks or regions for which a motion vector is coded exhibit motion that is similar to that of their neighbors. This can often be shown to be the case, for example when panning. However, it works less well if the motion field is irregular or where there are frequent transitions between background and foreground regions which have different motion characteristics.
For most modern video codecs, motion prediction is an important part of the compression process. Motion prediction is a process whereby the motion of objects or regions of the image is modeled over one or more frames and one or more ‘motion vectors’ is transmitted in the bitstream to represent this motion. In most cases it is not possible to perfectly model the motion within an image, so it is necessary to code a residual error signal in addition to the motion information.
In essence, each motion vector points to a region in a previously encoded frame that is similar to the region in the current frame that is to be encoded. The residual error signal is obtained by subtracting the predicted value of each pixel from the actual value in the current frame.
Many modern video codecs extend the process by providing support for prediction of motion to sub pixel accuracy, e.g, half-pixel or quarter-pixel motion estimation. To create fractional pixel data points, it is necessary to use some form of interpolation function or filter applied to real (i.e. full pixel aligned) data points.
Early codecs generally used simple bilinear interpolation as shown in Figure 1 attached hereto. In this example, A, B, C, and D are full-pixel aligned data points and x, y, and z are half-pixel aligned points. Point x is half-pixel aligned in the X direction and can be calculated using the equation:
x =( A+B )/2. (1)
Point y is half-pixel aligned in the Y direction and can be calculated using the equation:
y =( A+C )/2. (2)
Point z is half-pixel aligned in both X and Y can be calculated using the equation:
z =( A+B+C+D )/2. (3)
Later codecs have tended to move towards the use of more complex interpolation filters, such as bicubic filters, that are less inclined to blur the image. In the example shown in Figure 2, x is a half-pixel point that lies half way between two full pixel aligned pointes B and C. Using an integer approximation to a bicubic filter it can be calculated using the equation:
x =( −A +9 B +9 C−D )/16. (4)
Though filters such as the one illustrated above tend to produce sharper looking results, their repeated application over several frames can in some situations result in unpleasant artifacts such as false textures or false contouring.
When transmitting compressed video data over an unreliable or questionable data link, it is important that a mechanism exists for recovering when data is lost or corrupted, as video codecs are often extremely sensitive to errors in the bitstream.
Various techniques and protocols exist for the reliable transmission of data of such links, and these typically rely upon detection of the errors and either re-transmission or the use of additional data bits that allow certain types of error to be corrected. In many situations the existing techniques are adequate, but in the case of video conferencing over restricted bandwidth links neither of the above mentioned approaches is ideal. Re-transmission of lost data packets may not be practical because it is likely to cause an increased end to end lag, while the use of error correction bits or packets may not be acceptable in situations where bandwidth is already severely restricted.
An alternative approach is simply to detect the error at the decoder and report it to the encoder. The encoder can then transmit a recovery frame to the decoder. Note that this approach may not be appropriate if the error rate on the link is very high, e.g., more than one error in every 10-20 frames.
The simplest form of recovery frame is a key frame (or intra only frame). This is a frame that does not have any dependencies on previous frames or the data therein. The problem with key frames is that they are usually relatively large.
SUMMARY
Disclosed herein are aspects of systems, methods, and apparatuses for encoding and decoding video signals.
One aspect of the disclosed implementations is a method of compressing video data having at least one frame having at least one block having an array of pixels. The method includes transforming the pixels of the at least one block into coefficients; creating a default transmission order of the coefficients; creating an optimal transmission order of the coefficients; comparing a coefficient position of at least one of the coefficients in the optimal transmission order with a coefficient position of the at least one of the coefficients in the default transmission order; determining an update value based on the comparison, the update value indicative of whether the coefficient position of the at least one of the coefficients in the optimal transmission order is the same as the coefficient position of the at least one of the coefficients in the default transmission order; and selectively encoding position information of the at least one of the coefficients in the optimal transmission order based on the update value.
Another aspect of the disclosed implementations is an apparatus for compressing video data having at least one frame having at least one block having an array of pixels. The apparatus comprises a memory and a processor configured to execute instructions stored in the memory to: transform the pixels of the at least one block into coefficients; create a default transmission order of the coefficients; create an optimal transmission order of the coefficients; compare a coefficient position of at least one of the coefficients in the optimal transmission order with a coefficient position of the at least one of the coefficients in the default transmission order; determine an update value based on the comparison, the update value indicative of whether the coefficient position of the at least one of the coefficients in the optimal transmission order is the same as the coefficient position of the at least one of the coefficients in the default transmission order; and selectively encode position information of the at least one of the coefficients of the optimal transmission order based on the update value.
Another aspect of the disclosed implementations is an apparatus for compressing video data having at least one frame having at least one block having an array of pixels. The apparatus includes means for transforming the pixels of the at least one block into coefficients; means for creating a default transmission order of the coefficients; means for creating an optimal transmission order of the coefficients; means for comparing a coefficient position of at least one of the coefficients in the optimal transmission order with a coefficient position of the at least one of the coefficients in the default transmission order; means for determining an update value based on the comparison, the update value indicative of whether the coefficient position of the at least one of the coefficients in the optimal transmission order is the same as the coefficient position of the at least one of the coefficients in the default transmission order; and means for selectively encoding position information of the at least one of the coefficients in the optimal transmission order based on the update value.
It is an object of the invention to provide a video compression method and codec that is efficient and reliable.
It is another object of the invention to provide a video compression method and codec that can perform discrete cosine transforms in an adaptive manner.
It is another object of the invention to provide a video compression method and codec that performs entropy coding that optimizes the resources of the hardware devices being employed.
It is another object of the invention to provide a video compression method and codec that enhances motion vector coding.
It is another object of the invention to provide a video compression method and codec that accurately and efficiently performs fractional pixel motion prediction.
It is another object of the invention to provide a video compression method and codec that performs error recovery efficiently, even in the environment of a video conference.
The above and other objects are fulfilled by the invention, which is a method of compressing video data having at least one frame having at least one block and each block having an array of pixels. The disclosure includes at least one of the following steps: I) transforming the pixels of each block into coefficients and creating an optimal transmission order of the coefficients; II) optimizing the speed of processing compressed video data by partitioning the data bitstream and coding each partition independently; III) predicting fractional pixel motion by selecting an interpolation method for each given plurality of pixels depending upon at least one metric related to each given block; and IV) enhancing error recovery for a current frame using a frame prior to the frame immediately before the current frame as the only reference frame for lessening quality loss during data transmission.
As for the coefficient reordering aspect of the invention, the method transforms the pixels of each block into coefficients, each coefficient having a coefficient position and a value and determines a position value related to each coefficient position. An optimal transmission order of coefficients is then created based on the position values of each coefficient position, and the coefficients are transmitted in the order so determined. Preferably, the transmission order of coefficients is dynamically re-ordered for each frame of video data. The transforming step preferably transforms the pixels into discrete cosine transform coefficients. The transmission order of coefficients may be transmitted along with the coefficients. Preferably, each block has the same number of coefficients and coefficient positions, and each corresponding respective coefficient position conveys the same respective information from block to block.
In an effort to reduce the amount of data being transmitted, the transmission of coefficient order data may be limited to changes in the coefficient order from one frame to the next frame. Alternatively or in addition, the transmission order may be consolidated into bands of coefficients, each band having a plurality of coefficients organized by rank in numbers determined above. In this case, only band information may be transmitted along with the coefficients. Preferably, only band information will be transmitted where a coefficient changes bands from one frame to the next. As another alternative, all band information may always be transmitted.
Reordering the coefficients can also include the provision of a key frame. The inventive method may provide such a key frame which is always completely self-encoded and requires no information from or about a previous frame. In such a case, the encoder determines if a given frame is a key frame. If it is determined that the given frame is a key frame, the entire transmission order of coefficients for the key frame is transmitted. If it is determined that the given frame is not a key frame, only changes in the transmission order of coefficients from the previous frame to the given frame are transmitted.
As mentioned above, the invention contemplates optimizing the speed of processing compressed video data by partitioning the data bitstream and coding each partition independently. Specifically, the invention divides the video data into at least two data partitions and selects an optimal entropy coding method for each data partition. The entropy coding methods thus selected are applied respectively to each data partition. In one embodiment, the video data is divided into a predictor token data partition and an error token data partition; preferably, each data partition undergoes a different entropy coding method, such as Huffman coding and arithmetic coding. The various decoding processes of the different data partitions may be performed asynchronously and/or independently. This may be accomplished by providing at least two subprocessors in the hardware, wherein one data partition is decoded by one subprocessor and another data partition is decoded by another subprocessor. Determining which entropy coding method is to be used for a given data partition may be based on the size of the given data partition.
In one embodiment of the method and codec, the predictor token data partition is read and converted into a predictor block. The error token data partition is also read and is converted into coefficients and thence an error block. The predictor block and the error block are summed to form an image block. As mentioned above, it is preferable to provide at least two subprocessors, wherein some of these steps are performed on one subprocessor and the rest of the steps are performed on another subprocessor. Specifically, the steps of reading the error token data partition and converting the error token data partition into coefficients are preferably performed by a fast entropy optimized subprocessor, and the other steps are preferably performed by a general purpose subprocessor.
The method optimizes decoder performance of the bitstream in a way that avoids data and code cache misses. As many distinct functions of the decoder's code as can fit into the code cache are stored there. The code from this step is run for as many blocks as can fit into the data cache. The next set of distinct functions of the decoder's code and then collected, and the process is repeated until all of the bitstream has been read and each of the blocks of data have been produced.
Another aspect of optimizing decoder performance of the bitstream optimizes the utilization of the subprocessors by assigning each subtask to a separate processor. Preferably, the portion of the decoder that reads error tokens from the bitstream and translates them into coefficients is run on a fast entropy optimized subprocessor. The portion of the decoder that reads the predictor tokens from the bitstream and builds a filtered predictor block from these tokens is run on a subprocessor with fast access to memory. The portion of the decoder that translates the transform coefficients from the above step into an error signal is run on a subprocessor that has an optimized implementation of the transform coder, and the portion of the decoder that adds the predictor block to the error signal is run on a subprocessor optimized for motion compensation.
The video data may be divided into two data partitions, a first data partition representing a first area of the frame and a second data partition representing a second area of the frame (e.g,. upper and lower halves or left and right halves). Alternatively, the video data may be divided into three data partitions, each respectively representing level, saturation, and hue information of the frame. In another version, the three data partitions could respectively represent cyan, magenta, and yellow information of the frame.
As mentioned before, the invention includes the aspect of predicting fractional pixel motion by selecting an interpolation method for each given plurality of pixels depending upon at least one metric related to each given block. Specifically, the value of the at least one metric associated with a given plurality of pixels to encode is determined, and an interpolation method of encoding the given plurality of pixels is selected depending upon the value of the at least one metric determined. The interpolation method thus selected is applied to the given plurality of pixels to encode, and the process is repeated steps for each successive plurality of pixels. The at least one metric may be at least one of motion vector length and a complexity factor. The interpolation methods may include bilinear, bicubic, quadratic, and B-spline interpolation. The given plurality of pixels may be an entire frame or a sub-portion thereof. If the motion vector length associated with the given plurality of pixels is determined to be less than the predetermined length value and the complexity factor associated with the given plurality of pixels is determined to be greater than the predetermined complexity value, then bicubic interpolation is selected. A predetermined length value and the predetermined complexity value is preferably set one time for a given number of pluralities of pixels, and possibly once per frame.
The complexity factor is preferably a variance of the given plurality of pixels, calculated as
C =( n Ex i 2 −( Ex i ) 2 )/ n 2 (4)
As mentioned above, the invention includes enhancing error recovery for a current frame using a frame prior to the frame immediately before the current frame as the only reference frame for lessening quality loss during data transmission. Specifically, the invention includes using a frame coded prior to the last frame as the only reference frame for a given frame in order to lessen the quality loss associated with transmission over lines which produce lost or corrupt packets. This step is limited to at least one of periodically (every F frames) and arbitrarily (based on some other criteria).
This aspect of the invention is particularly well-suited for a video conference. Specifically, each party to a video conference compresses frames of video data and transmits the compressed video data to the other parties with packets that are marked such that the loss or corruption of a packet is detectable. If any party detects that a packet is lost or corrupted, the detecting party signals the sending party to send an update frame that has been encoded using a reference frame that has already been successfully received and decoded by all of the remaining parties.
The invention may preferably use reference frames in the following manner. A fixed interval F of video frames may be selected by the encoder and transmitted to the decoder. Every F′th frame is encoded using only the previous encoded F′th frame for reference. Every non F′th frame is encoded using the prior frame as reference. Each frame of video is transmitted to the decoder so that loss and corruption are detectable. All of these steps preferably occur at the encoder. On the decoder side, the coded video data is received from the encoder and decoded by the decoder. If a packet is lost and the lost packet is associated with a non F′th frame, the decoder waits for the next F′th frame to recover the lost packet.
As another alternative, the invention encodes a current frame at least one of periodically and arbitrarily at a higher than ambient quality determined by a metric of statistics taken from this and prior coded frames and stores the encoded current frame for usage by subsequent frames as a secondary reference frame.
Variations in these and other aspects will be described in additional detail hereafter.
DETAILED DESCRIPTION
Several different aspects of the invention will be described hereinafter.
Dynamic Coefficient Reordering
In DCT (Discrete Cosine Transform) based video compression systems an 8 by 8 block of pixel or prediction error signal data is transformed into a set of 64 frequency coefficients (a DC value and 63 AC values), which are then quantized and converted into a set of tokens.
Typically the higher frequency AC coefficients are smaller in magnitude and hence less likely to be non zero following quantization. Consequently, prior to tokenization the coefficients are often arranged into ascending order starting with the lowest frequency coefficient (the DC value) and finishing with the highest frequency AC coefficient. This scan order, sometimes referred to as “zig-zag order”, tends to group together the non-zero values at the start and the zero values into runs at the end and by so doing facilitates more efficient compression.
However, this fixed scan order is seldom optimal. For example, when encoding interlaced video material, certain high frequency coefficients are much more prominent. This fact is reflected in the prior art where there are examples of codecs (for example MPEG-2), that mandate an alternative scan order for use when coding interlaced video.
One aspect of the invention is a method whereby a codec can optionally customize the scan order in which coefficients are encoded to more optimally reflect the characteristics of a particular data set.
According to this invention the codec maintains a record of the distribution of zero vs. non-zero values for each of the DCT coefficients, in one or more frames of video. This record is used to create a custom scan order where coefficients that are more likely to be non-zero appear earlier in the list.
The codec may optionally collate additional information such as the average magnitude of the non-zero values for each coefficient and use this to further optimize the scan order.
The overhead of transmitting a new custom scan order, or updating a previously transmitted scan order, may in some cases negate the benefit gained from improved coefficient coding efficiency. Hence, a cost benefit analysis may be necessary to determine if the update provides a net benefit.
The main factors affecting the outcome of this analysis are the cost of update, the number of blocks (and hence coefficients) to be encoded and the extent to which the new scan order deviates from either a standard scan order or a previously encoded scan order.
For an 8×8 element DCT, coding a “complete” custom scan order (i.e., a new position for every one of the 64 coefficients), would require 384 bits (64 coefficients×6 bits each). This cost is likely to be prohibitive unless the number of blocks (and hence coefficients) to be coded is very large or the optimum scan order differs very significantly from the default scan order (this being either a standard scan order or one previously encoded). The rationale behind this statement is that if the default scan order is similar to the custom scan order, then the average number of bits saved coding each block is likely to be small, hence a large number of blocks must be coded to justify the overhead of updating the scan order. Conversely if the default scan order is dissimilar to the custom scan order, then the average saving per block is likely to be high.
A simple way to improve this situation would be to only code changes to the scan order. For example, for each coefficient, code a bit to indicate whether it has changed its position in the scan order and then if appropriate its new position. Though this will typically result in a lower update cost, the worst case scenario here is where the new scan order is different for all coefficients, in which case the cost of update would be 448 bits (64×7).
An attractive aspect of such an approach is that the cost of update is lowest where the custom and default scan order are most similar (and hence the likely cost saving per block is at its lowest), and highest when they are most dissimilar.
The situation can be improved still further by considering cost benefit at the level of individual coefficients or pairs of coefficients. Consider, for example, a case where two coefficients are adjacent to one another in the scan order and where the likelihood of a non-zero value is almost identical for both. A small change in the number of non-zero values for one or other of the two coefficients could cause them to swap places in the custom scan order. To encode this change would mean updating the scan position for both coefficients at a cost of 14 bits (assuming the update model above). However, the saving achieved might be negligible. This problem is particularly relevant in respect of the high order AC coefficients. Here, the frequency of non-zero values is typically very low and even a tiny change could cause a coefficients' position in the scan order to change significantly.
While it is certainly feasible to base the calculation of a custom scan order purely upon the distribution of zeros vs. non-zeros for each coefficient, there are other factors that are relevant. As mentioned previously, one of these is the average magnitude of the non-zero values. Another is the fact that in some cases a positive correlation may exist between the values of one or more coefficients. For example, between a low order “pure horizontal” AC coefficient and higher order ‘pure horizontal’ coefficients. In such cases, unless there is a substantial difference in the prevalence of non-zero values, it may be preferable to keep them in their original order (lowest frequency to highest frequency).
The preferred implementation of this aspect of the invention goes some way to addressing such issues whilst further reducing the cost of updating the scan order. The procedure for creating a custom scan order is broadly as follows:
(a) The DC coefficient is always coded first (position 0)
(b) Order the AC coefficients into descending order based upon the proportion of the values that are non-zero for each coefficient.
(c) Split the ordered list into 16 variable sized bands (see table 1)
(d) Within each band re-order into zig-zag scan order.
Note that the subdivision into 16 bands as shown in Table 1 is based upon empirical observations with a range of different test clips and is not necessarily optimal.
TABLE 1
Preferred scan order coefficient bands
Band
First coefficient
Last coefficient
0
1
1
1
2
4
2
5
10
3
11
12
4
13
15
5
16
19
6
20
21
7
22
26
8
27
28
9
29
34
10
35
36
11
37
42
12
43
48
13
49
53
14
54
57
15
58
63
Empirical experiments show that this banding strategy gives results that are usually as good as and often better than those obtained using a scan order based purely upon the proportion of the values that are non zero; even before the cost of update is taken into account.
The second advantage is that the cost of updating the scan order is greatly reduced because it is only necessary to update a value when it moves from one band to another. Further, only 4 bits are needed to code a change in band.
A final optimization used in the preferred implementation is based upon the observation that some coefficients change bands much more frequently than others. For example, the high order AC coefficients tend to change bands less often than the low order coefficients.
If a particular coefficient is only updated 2% of the time, for example, then it is wasteful to use 1 bit to indicate whether or not it is to be updated on a given frame. By using arithmetic coding techniques and assigning empirically determined update probabilities to each coefficient, it is possible to get the average update cost substantially below 1 bit per coefficient.
The following “C” code segments give supporting detail of the preferred implementation of this aspect of the invention.
// Work out a new “preferred” scan order using the zero/non-zero frequency data
// that has been collected.
void CalculateScanOrder ( CP_INSTANCE *cpi ) {
UINT32 i, j, k;
UINT32 Sum;
UINT32 tmp[2];
UINT32 NzValue [BLOCK_SIZE][2]; UINT32 GroupStartPoint, GroupEndPoint;
// For each coefficient, calculate the proportion of the values that 11 were non-zero as a scaled number from 0-255.
for ( i=1; i<BLOCK_SIZE; i++ )
{
Sum = cpi->FrameNzCount[i][0J + cpi->FrameNzCount[i][1]; if( Sum )
NzValue [i][0] = (cpi->FrameNzCount[i][I]*255)/Sum; else
NzValue [i] [0] = 0;
NzValue [i][1] = i;
}
// Sort into decending order
for ( i=1; i<BLOCK SIZE−1; i++ )
{
for ( j =i+1; j>1; j−− )
{
if ( NzValue [j][0] > NzValue [j−l][0] ) {
// Swap them over
tmp[O] = NzValue [j− MO]; tmp[1] = NzValue [j−l][1];
NzValue [j−I][0] =NzValue [j][0]; NzValue [j−l][1] = NzValue [j][1];
NzValue [j][0] = tmp[O]; NzValue [j][1] = tmp[1];
}
}
}
//Split into bands and then re-sort within each band
// into ascending order based upon zig-zag scan position
GroupEndPoint = 0;
for ( k=0; k<SCAN_ORDER BANDS; k++ ) {
GroupStartPoint = GroupEndPoint + 1;
GroupEndPoint EndpointLookup[k];
for ( i=GroupStartPoint; i<GroupEndPoint; i++ )
{
for ( j =i+1; j>GroupStartPoint; j−− )
{
if( NzValue [j][1] < NzValue [j−1][l] ) {
// Swap them over
tmp[O] = NzValue U−1][0];
tmp[1] =NzValue [j−l][1];
NzValue [j−I][0] = NzValue [j][0];
NzValue [1−1][1] = NzValue NzValue [j][0] = tmp[0];
}
}
// For each coef index mark its band number
for ( i=GroupStartPoint; i<<GroupEndPoint; i++ )
{
// Note the new scan band number for each coef.
// NzValue [i][1] is the position of the coef in the traditional
// zig-zag scan order, i is the position in the new scan order and /I k is the band number,
cpi->NewScanOrderBands[ NzValue [i][1J ] = k;
}
}
}
// This structure gives scan order update probabilities (scaled to the range of 1-255)
// for each of the dct coefficients (in traditional zig-zag order). The values are passed
// to the function “nDecodeBoolO” and indicate the probability that the result will be 0
// (FALSE).
//
const UINT8 ScanBandUpdateProbs[BLOCK SIZE] —
{
255, 132, 132, 159, 153, 151, 161, 170,
164, 162, 136, 110, 103, 114, 129, 118,
124, 125, 132, 136, 114, 110, 142, 135,
134, 123, 143, 126, 153, 183, 166, 161,
171, 180, 179, 164, 203, 218, 225, 217,
215, 206, 203, 2I7, 229, 241, 248, 243,
253, 255, 253, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255
};
// Reads updates to the scan order if they are available for this frame.
void UpdateScanOrder( PB INSTANCE*pbi )
{
// Is the scan order being updated this frame?
If (nDecodeBool( 128 ) )
{
// Read in the those scan bands that have been updated for (i = l; i < BLOCK SIZE; i++ )
for (i = l; i < BLOCK SIZE; i++ )
{ U Has the band for this coefficient been updated?
if( nDecodeBool( ScanBandUpdateProbs[i] ) )
{
pbi->ScanBands[i] = VP6_bitread( SCAN_BAND UPDATE BITS );
}
//Build the new scan order from the scan bands data BuildScanOrder( pbi, pbi->ScanBands );
}
}
// Builds a custom scan order from a set of scan band data,
void BuildScanOrder( P8 _INSTANCE *pbi, UINT8 *ScanBands ) {
UINT32 i, j;
UINT32 ScanOrderIndex =1;
// DC is fixed pbi->ModifedScanOrder[O] = 0;
// Create a scan order where within each band the coefs are in ascending order
// (in terms of their original “zig-zag” scan order positions).
for ( i = 0; i < SCAN_ORDER BANDS; i++ ) {
for (j = 1; j < BLOCK SIZE; j++ ) {
if( ScanBands[j] == i ) {
pbi->ModifiedScanOrder[ScanOrderindex] = j;
ScanOrderindex++;
}
}
}
}
Using Independent Bitstream Partitions to Facilitate Encoder and Decoder Optimization, and Using of Mixed Mode Entropy Coding
When optimizing a codec for a specific hardware device, it is important to make sure that full use is made of any facilities that the device may offer for performing multiple tasks in parallel and to limit the extent to which individual parts of the decode process become bottlenecks.
The inventive bitstream, in common with most other video codecs, can broadly speaking be described as comprising entropy coded tokens that can be divided into two main categories.
(a) Predictor tokens (hereinafter referred to as P tokens). For example, tokens describing the method or mode used to code a block or region of an image and tokens describing motion between one frame and another.
(b) Prediction Error signal tokens (hereinafter referred to as E tokens). These are used to code any residual error that results from an imperfect prediction.
Entropy coding is a process whereby the representation of a specific P or E token in the bitstream is optimized according to the frequency of that token in the bitstream or the likelihood that it will occur at a particular position. For example, a token that occurs very frequently will be; represented using a smaller number of bits than a token that occurs infrequently.
Two of the most common entropy coding techniques are Huffman Coding and arithmetic coding. In Huffman coding each token is represented by a variable length pattern of bits (or a code). Arithmetic coding is a more computationally complex technique but it removes the restriction of using a whole number of bits for each token. Using an arithmetic coder it is perfectly possible, for example, to code a very common token at an average cost of ½ of a bit.
Many multimedia devices have a co-processor unit that is well suited to the task of entropy coding and a more versatile main processor. Consequently, for the purpose of parallelization, the process of encoding or decoding a bitstream is often divided into entropy related tasks and non entropy related tasks.
However, for a given video clip, as the data rate increases the number of tokens to encode/decode rises sharply and entropy coding may become a bottleneck.
With a conventional bitstream it is very difficult to re-distribute the computational load of entropy coding to eliminate this bottleneck. In particular, on the decode side, the tokens must normally be decoded one at a time and in the order in which they were encoded. It is also extremely difficult to mix methods or entropy encoding (for example Huffman and arithmetic coding) other than at the frame level.
This aspect of the invention is a method designed to make it easier to redistribute the computational load of entropy coding, and to facilitate the use of mixed mode entropy coding through structural changes to the bitstream.
According to this method each frame in the bitstream is divided into two or more wholly independent data partitions. The partitions may be written to or read from in parallel and are not constrained to use the same entropy encoding mechanism. This makes it easier to optimize the process of encoding or decoding to avoid entropy related bottlenecks at high bit-rates.
The ability to use both Huffman and arithmetic techniques, or a mixture of the two, within a single frame, gives the encoder the ability to better optimize the tradeoff between the amount of compression achieved and computational complexity. For example, an encoder could be configured to use the less complex Huffman method in one or more of its partitions if the projected size of a frame exceeded a given threshold.
The specific implementation of this aspect of the invention supports the use of either one or two main data partitions. In addition there is a small header partition.
When using a single data partition the codec behaves in a conventional manner. Both P and E tokens are coded using a proprietary arithmetic coder in a single data partition. This method has slightly lower overheads (a few bits per frame) but is less flexible. For example:
Partition 1
(block 1)
P, P, E, E, E
(block 2)
P, E, E,
(block 3)
P, P, E, E, E,
In the second case, however, the P and E tokens are written to separate partitions. For example:
Partition 1
Partition 2
(block 1)
PP
EEE
(block 2)
P
EE
(block 3)
P
EEEE
The size of the first partition does not tend to vary as much with data rate, and is comparatively small, so this partition is always coded using the arithmetic coder. The second partition may be coded using either the arithmetic coder or the Huffman coder.
The choice of Huffman or arithmetic coding for the second partition can be signaled at the frame level. In the preferred implementation the choice depends upon the performance of the target decoder platform and the projected size in bits of the frame. Specifically, if the frame size rises above a threshold number, where there is a danger that the decoder will have problems decoding the frame in real time, then the Huffman method is used.
Encoder performance can also be an issue where real time encoding is a requirement, but with the possible exception of key frames (which tend to be larger and have no dependencies on other frames), the cost of the entropy coding is usually a smaller fraction of the total computational cost in the encoder.
The following “C” code segments give supporting detail of the preferred implementation of this aspect of the invention.
//This function packs the encoded video data for a frame using either one arithmetically
// coded data partition, two arithmetically coded data partitions, or one arithmetically
// coded data partition and one Huffman data partition.
//
//The argument “cpi” is a pointer to the main encoder instance data structure.
void PackCodedVideo ( CP_1NSTANCE *cpi )
{
UINT32 PartitionTwoOffset;
BOOL CODER *bc &cpi->bc; // Arithmetic coder instance data structure
B O O L CODER *bc2 &cpi->bc2; // 2nd Arithmetic coder instance structure
P8 ...INSTANCE *pbi = &cpi->pb; // Decoder instance data structure
// Initialize the raw buffer i/o used for the header partition.
InitAddRawBitsToBuffer ( &cpi->RawBuffer, pbi->DataOutputPtr );
// Start the arithmetic and or Huffman coders
// If we are using two data partitions...
if( pbi->MultiStream I I (pbi->VpProfile = SIMPLE PROFILE) )
{
//Start the first arithmetic coder: Allow for the raw header bytes.
VP6_StartEncode ( bc, (pbi->DataoutputPtr + ((KeyFrame) ? 4 : 3)) );
// Create either a second arithmetic or Huffman partition
// This is initially written to a holding buffer “cpi->OutputBuffer2”
if ( pbi->UseHuffman )
InitAddRawBitsToBuffer ( &pbi->HufBuffer, cpi->OutputBuffer2 );
else
VP6_StartEncode ( bc2, cpi->OutputBuffer2 );
// We are only using a single data partition coded using the arithmetic coder. else
{
//Start the arithmetic coder: Allow for the raw header bytes.
VP6_StartEncode( bc, (pbi->DataOutputInPtr + ((KeyFrame) ? 2 : 1)) );
// Write out the frame header information including size.
WriteFrameHeader (... );
if( pbi->UseHuffman )
PackHufmmanCoeffs (... );
else
PackArithmeticCoeffs (... );
// Stop the arithmetic coder instance used for the first data partition
VP6_StopEncode ( be );
//Work out the offsets to the data partitions and write them into
// the space reserved for this information in the raw header partition.
//
// If we are using two data partitions....
if( pbi->MultiStream I I (pbi->VpProfile = SIMPLE PROFILE) )
{
// Offset to first data partition from start of buffer
PartitionTwoOffset = 4 + be->pos;
//Write offset to second data partition partition.
AddRawBitsToBuffer ( &cpi->RawBuffer, PartitionTwoOffset ,16 );
// If Huffman was used for the second data partition ...
if( pbi->UseHuffman )
{
// Flush the buffer for the Huffman coded output partition
EndAddRawBitsToBuffer ( &pbi->HuffBuffer );
// Copy the Huffman coded data from the holding buffer into the output buffer.
memcpy ( &cpi->RawBuffer.Buffer[ PartitionTwoOffset ], pbi->HuffBuffer.Buffer, pbi->HuffBuffer.pos );
// Stop the arithmetic coder instance used by the second data partition.
VP6_StopEncode ( bc2 );
//Copy over the contents of the holding buffer used by
//the second partition into the output buffer.
>DataOutputlnPtr[ PartitionTwoOffset ],
bc2.buffer, bc2.pos );
}
)
// Stop and flush the raw bits encoder used for the header
EndAddRawBitsToBuffer ( &cpi->RawBuffer );
}
//This function is called to select the coding strategy when using two data partitions.
void SelectMultiStreamMethod ( CP _INSTANCE *pbi )
{
// Calculate an estimated cost (Shannon entropy) for the frame using
// the information gathered re, the distribution of tokens in the frame.
// Add in the previously calculated cost estimate for coding any mode and 11 motion vector information.
EstimatedFrameCost = VP6_ShannonCost( cpi ) + ModeMvCost;
// Decide whether to drop using Huffman coding for the second data partition. )
if ( EstimatedFrameCost > HuffmanCodingThreshold ) pbi->UseHuffman = TRUE;
else
pbi->UseHuffman = FALSE;
}
Using a Plurality of Filters to Enhance Fractional Pixel Motion Prediction in Video Codecs
For most modem video codecs motion prediction is an important part of the compression process. Motion prediction is a process whereby the motion of objects or regions of the image is modeled over one or more frames and one or more motion vectors is transmitted in the bitstream to represent this motion. In most cases it is not possible to perfectly model the motion within an image, so it is necessary to code a residual error signal in addition to the motion information,
In essence, each motion vector points to a region in a previously encoded frame that is similar to the region in the current frame that is to be encoded. The residual error signal is obtained by subtracting the predicted value of each pixel from the actual value in the current frame.
Many modem video codecs extend the process by providing support for prediction of motion to sub pixel accuracy. For example half pixel or quarter pixel motion estimation. To create fractional pixel data points it is necessary to use some form of interpolation function or filter applied to real (i.e. full pixel aligned) data points.
Early codecs generally used simple bilinear interpolation
A
x
B
y
z
C
D
In this example, A, B, C, and D are full pixel aligned data points and x, y, and z are half pixel aligned points. Point x is half pixel aligned in the X direction and can be calculated using the formula: x=(A+B)/2. Point y is half pixel aligned in the Y direction and can be calculated using the formula: y=(A+C)/2. Point z is half pixel aligned in both X and Y can be calculated using the formula: z=(A+B+C+D)/2.
Later codecs have tended to move towards the use of more complex interpolation filters, such as bicubic filters, that are less inclined to blur the image. In the following example x is a half pixel point that lies half way between two full pixel aligned pointes B and C. Using an integer approximation to a bicubic filter it can be calculated using the formula: x=(−A+9B+9C−D)/16.
A B×C D
Though filters such as the one illustrated above tend to produce sharper looking results, their repeated application over several frames can in some situations result in unpleasant artifacts such as false textures or false contouring.
This aspect of the invention is a method where by a codec can use a mixture of filtering techniques to create more optimal fractional pixel predictors and select between these methods at the clip level, the frame level, the block level or even at the level of individual pixels.
In the preferred implementation a selection can be made on a per frame basis as to whether to use bilinear filtering only, bicubic filtering only or to allow a choice to be made at the block level.
Selection at the block or region level could be achieved by means of explicit signalling bits within the bitstream, but in the preferred implementation selection is made using contextual information already available in the bitstream and by means of a complexity metric applied to the full pixel aligned data values that are going to be filtered.
In situations where the quality of the motion predictor is poor (for example if it was not possible to find a good prediction for a block in the previous frame reconstruction), bilinear filtering is often the best option. Specifically where the prediction is poor the sharpening characteristics of the bicubic filter may lead to an increase in the high frequency content of the residual error signal and make it more difficult to encode.
In the absence of explicit signalling bits in the bitstream various contextually available values that can be shown to be correlated to a greater or lesser extent with poor prediction quality. One of the simplest of these is motion vector length. Specifically the quality of the prediction tends to degrade with increasing motion vector length. The smoothness of the motion field in is another possible indicator (i.e. how similar are the motion vectors of neighbouring blocks).
Bilinear filtering also tends to be the better option in situations where the choice of vector is unreliable (for example, where there is not very much detail in the image and there are many candidate vectors with similar error scores). In particular, repeated application of a bicubic filter over many frames, to a region that is relatively flat and featureless, may give rise to unwanted artifacts.
In the preferred implementation two factors are taken into account when choosing the filtering method. The first is the length of the motion vector. The second is a complexity metric C calculated by analyzing the set of full pixel aligned data points that are going to be filtered.
Bicubic filtering is used only if both the following test conditions are satisfied:
1. The motion vector is shorter than a threshold value L in both X and Y.
2. The complexity C is greater than a threshold value T.
In the preferred implementation C is a variance of a set of n data points xi calculated according to the formula:
C =( nExi 2− ( Exi ) 2 )/ n 2 (4)
In the preferred implementation the complexity threshold T and the motion vector length threshold L may be set by the encoder on a once per frame basis.
The following “C” code segments give supporting detail the preferred implementation of this aspect of the invention.
PredictBlockFunction(... )
{
if ( pbi->PredictionFilterMode = AUTO_SBLECT PM) {
// Use bilinear if vectors are above a threshold length in X or Y
if( (( abs(pbi->mbi.Mv[bp].x ) > BicMvSizeLimit) II ((
abs(pbi->mbi.Mv[bp].y ) > BicMvSizeLimit) )
{
FilterBlockBilinear(.., );
}
else
{
//Calculate a complexity metric (variance).
//Note: for performance reasons the variance function only
// examines 16 data points (every other point in X and Y
// for an 8×8 block).
Var = Varl6Point( DataPtr, Stride );
//If the complexity is above the given threshold use bicubic else
use bilinear
if( Var >= pbi->PredictionFilterVarThresh )
FilterBlockBilcubic(... );
else FilterBlockBilinear( );
}
}}
UINT32 Varl6Point ( UINT8 *DataPtr,1NT32 Stride ) {
UINT32 i, j;
UINT32 XSum=O, XXSum=O;
UINT8 *Dif f tr = DataPtr;
//Use every other point in X and Y
for ( i = 0; i < BLOCK HEIGHT WIDTH; I += 2 )
for (j = 0; j < BLOCK_HEIGHT WIDTH; j += 2 )
{
XSum += DiffPtr[j];
XXSum += DiffPtr[j] * DiffPtr[j];
}
//Step to next row of block. DiffPtr +=
(SourceStride << 1)
//Compute population variance as mis-match metric,
return (( (XXSum* 16) − (XSum*XSum) ) 1256 );
}
Enhanced Motion Vector Coding
By convention, most modern video codecs code the (x,y) components of a motion vector, using a differential coding scheme. That is, each vector is coded relative to the previous vector. For example, consider two vectors (7,3) and (8,4). In this case the second vector would be encoded as (1,1), that is (7+1, 3+1).
This scheme works well if most blocks or regions for which a motion vector is coded exhibit motion that is similar to that of their neighbours. This can often be shown to be the case, for example when panning. However, it works less well if the motion field is irregular or where there are frequent transitions between background and foreground regions which have different motion characteristics.
This aspect of the invention is an alternative strategy for encoding motion vectors which retains the advantages of differential coding whilst being more tolerant of irregular fields and background foreground transitions.
According to this invention, the codec maintains two or more reference vectors relative to which motion vectors may be encoded. The codec could switch between these reference vectors via explicit signalling bits within the bitstream, but in the preferred implementation the decision is based upon the coding methods and motion vectors used by the blocks' immediate neighbours.
In the preferred implementation, a block may be coded as and intra block (with no dependency on any previous frames), or an inter block which is dependent upon either the previous frame reconstruction, or an alternative reference frame that is updated only periodically.
When coding with respect to the previous frame reconstruction or the alternative reference frame, the invention supports the following coding mode choices.
(a) Code with no motion vector (that is to say an implicit (0,0) vector)
(b) Code using the same vector as the ‘nearest’ neighbouring.
(c) Code using the same vector as the ‘next nearest’ neighbour.
(d) Code using a new motion vector.
When defining the nearest or next nearest neighbour, only blocks that are coded with respect to the same reference frame as the current block and those that are coded with a non-zero motion vector are considered. All other blocks are ignored.
When defining the next nearest neighbour, blocks that are coded with the same vector as the nearest neighbour are also ignored.
When coding a new motion vector the codec may use either (0,0) or the nearest vector as the reference vector. In the preferred implementation the nearest vector is used if the block from which it is derived is either the block immediately to the left or immediately above the current block (assuming that blocks are being coded from left to right and from top to bottom). In all other cases new vectors are coded with respect to (0,0).
Several extensions to the basic method are possible. If the nearest and next nearest neighbours are the blocks immediately to the left and immediately above the current block respectively, then some sort of compound vector derived from the two could be used as a reference for coding the new vector. Alternatively ‘nearest’ could be used to predict the x component and ‘next nearest’ the y component.
Another possible extension, still assuming that nearest and next nearest are the blocks immediately to the left and above the current block, would be to take special account of the case where the nearest and next nearest vectors are not similar, and in such a case revert to 0 as the reference value for x, y or both x and y.
This method retains the benefits of simple differential coding in cases where there is a regular or slowly changing motion field. However, the use of special ‘no vector’, ‘nearest’ and ‘next nearest’ modes makes for more efficient coding of transitions between foreground and background and the ability to switch automatically between multiple coding origins makes the method more tolerant of irregular motion fields.
The following “C” code segments give supporting detail of the preferred implementation of this aspect of the invention.
// This function determines whether or not there is a qualifying nearest and next
// nearest neighbour for the current block, what the motion vectors are for those
// and how close the nearest neighbour is.
//
void VP6_FindNearestandNextNearest( PB_INSTANCE *pbi,
UINT32 MBrow,
UINT32 MBcoI,
UINT8 ReferenceFrame
INT32 * Type )
{
int i;
UINT32 OffsetMB;
UINT32 BaseMB = MBOffset(MBrow,MBcol);
MOTION VECTOR ThisMv;
//Set default outcome
*Type = NONEAREST_MACROBLOCK;
// Search for a qualifying “nearest” block
for ( i=0; i<12 ; i++ )
{
OffsetMB = pbi->mvNearOffset[i] + BaseMB;
// Was the block coded with respect to the same reference frame?
if ( VP6_Mode2Frame[pbi->predictionMode[OffsetMB]] 1= ReferenceFrame) continue;
// What if any motion vector did it use
ThisMv.x = pbi->MBMotionVector[OffsetMB].x; ThisMv.y = pbi->MBMotionVector[OffsetMB].y;
//If it was non-zero then we have a qualifying neighbour
if ( ThisMv.x 11 ThisMv.y )
Nearest.x = ThisMv.x;
Nearest.y = ThisMv.y;
*Type = NONEAR_MACROBLOCK;
break; }
pbi->mbi.NearestMvIndex = i;
// Search for a qualifying “next nearest” block for ( i=i+1; i<12; i++ )
{
OffsetMB = pbi->mvNearOffset[i] + BaseMB;
//Was the block coded with respect to the same reference frame?
if ( VP6_Mode2Frame[pbi->predictionMode[OffsetMB]] != ReferenceFrame)
continue;
// What if any motion vector did it use
ThisMv.x = pbi->MBMotionVector[OffsetMB].x;
ThisMv.y = pbi->MBMotionVector[OffsetMB].y;
// If this vector is the same as the “nearest” vector then ignore it.
if( (ThisMv.x == Nearest.x) && (ThisMv.y Nearest,y) )
continue;
// If it was non-zero then we have a qualifying neighbour
if( ThisMv.x 1I ThisMv.y )
{
NextNearest.x ThisMv.x;
NextNearest.y ThisMv.y;
*Type = MACROBLOCK;
break;
}
Using An Alternate Reference Frame in Error Recover
When transmitting compressed video data over an unreliable data link it is important that a mechanism exists for recovering when data is lost or corrupted, as video codecs are often extremely sensitive to errors in the bitstream.
Various techniques and protocols exist for the reliable transmission of data of such links and these typically rely upon detection of the errors and either re-transmission or the use of additional data bits that allow certain types of error to be corrected.
In many situations the existing techniques are adequate but in the case of video conferencing over restricted bandwidth links neither of the above mentioned approaches is ideal. Re-transmission of lost data packets may not be practical because it is likely to cause an increased end to end lag, whilst the use of error correction bits or packets may not be acceptable in situations where bandwidth is already severely restricted.
An alternative approach is simply to detect the error at the decoder and report it to the encoder. The encoder can then transmit a recovery frame to the decoder. Note that this approach may not be appropriate if the error rate on the link is very high. For example, more than one error in every 10-20 frames.
The simplest form of recovery frame is a key frame (or intra only frame). This is a frame that does not have any dependencies on previous frames or the data therein. The problem with key frames is that they are usually relatively large.
Disclosed herein is a mechanism whereby a codec maintains a one or more additional references frames (other than the reconstruction of the previously coded frame) that can be used as a starting point for more efficiently coding of recovery frames.
In the preferred implementation of the invention the codec maintains a second reference frame which is updated whenever there is a key frame and optionally at other times, via a flag bit in the frame header. For example the encoder could choose to update the second reference frame once every ‘X’ seconds or whenever an error recovery frame is encoded.
Provided that the content of the second reference frame is at least in some respects similar to the content of the current frame, differential coding with respect to the second reference frame is likely to be much cheaper than coding a key frame.
There are several ways in which one or more alternate reference frames may be used to enhance compression quality or efficiency. One obvious usage that is covered in the prior art is in video sequences that oscillate back and forth between two or more different scenes. For example, consider an interview where the video switches back and forth between interviewer and interviewee. By storing separate reference frames as a baseline for each camera angle the cost of switching back and forth between these can be greatly reduced, particularly when the scenes are substantially different.
Whilst the invention has the option of using an alternate reference frame in this way, the subject of this invention is the use of a periodically updated alternate reference frame to enhance the quality of compressed video is situations where there is a slow progressive change in the video. Good examples of this are slow pans, zooms, or tracking shots.
According this aspect of the invention, during slow pans or other such slow progressive changes the encoder periodically inserts frames which are encoded at a significantly higher quality than the surrounding frames and which cause the second or alternative reference frame to be updated.
The purpose of these higher quality “second reference update” frames is to re-instate detail that has incrementally been lost since the last key frame, or the last second reference update, and to provide a better basis for inter frame prediction in subsequent frames. This strategy of periodically raising the quality (and hence the data rate) and at the same time updating the second reference frame can be shown to provide a much better cost/quality trade off in some situations than simply coding all the frames at a similar quality.
Central to an effective implementation is the method for determining an appropriate interval for the second reference updates and the amount by which the quality or data rate should be boosted.
In the preferred implementation of this aspect of the invention, several factors are taken into account. These include:
(a) The average amplitude of motion vectors in the preceding few frames as an indicator of the speed of motion.
(b) The extent to which the motion field is correlated. For example are the motion vectors all fairly similar.
(c) The extent to which the second reference frame has been used as a predictor in preference to the previous frame reconstruction in the previous few frames.
(d) The ambient quality or quantizer setting.
In cases where the average amplitude of the motion vectors used is high (indicating faster motion), the interval between second reference updates and the quality boost are both decreased. Conversely, where the motion is slow a larger quality boost and longer interval are used.
In cases where the motion field is highly correlated, that is to say that there are a lot of similar motion vectors, the quality boost for second reference frame updates is increased. Conversely, when the motion field is poorly correlated the extent of the boost is decreased.
In cases where the second reference frame is frequently being used as a predictor in preference to the previous frame reconstruction, the quality boost is increased. Conversely in cases where the second reference frame is not used frequently it is decreased.
The extent of the quality boost also depends to some extent on the ambient quality with a larger boost being used when the ambient quality is low and a smaller boost when the ambient quality is high.
The following pseudo code gives more detail of the preferred implementation of this aspect of the invention.
For each frame
Calculate of the average amplitude of the X and Y motion vector components (AvX and AvY) specified in pixel units.
MotionSpeed = the larger of AvX and AvY
Calculate a variance number for the X and Y motion vector components (VarianceX and VarianceY).
MaxVariance = the larger of VarianceX and VarianceY
MotionComplexity = MotionSpeed + (VarianceX 14) + (VarianceY l 4)
If a second reference frame update is due this frame
Calculate a data rate % boost number (Boost) based upon the predicted quality index (actually a quantizer setting)
for the frame, This can range between +0% at highest quality to +1250% when the quality level is very low.
Multiply Boost by a MotionSpeed correction factor where the factor can vary between 1 for very small values of
MotionSpeed to 0 for large values of MotionSpeed.
Apply a further correction factor to Boost based upon the extent to which the second reference frame has been used in the
previous few frames. This can vary from 1/16 in cases where the second reference frame was not used at all in the previous few
frames up to 1 in cases where it was used for 15% or more of the coded blocks.
A series of tests are then applied to determine whether or not to go ahead and update the second reference frame with the
calculated % boost.
The principal tests are:
(Boost>MinBoostTreshold) and
(MotionSpeed<MaxMotionSpeedThreshold) and
(MaxVariance<MaxVarianceThreshold) where MinBoostTreshold, MaxMotionSpeedThreshold and MaxVarianceThreshold are configurable parameters.
The invention has a number of special “motion re-use” modes that allow the motion vector for a block to be coded more cheaply if it is the same as the motion vector used by one of its near neighbours. Further tests are applied to discount cases where the usage of these modes falls below a threshold level.
If the decision is made to apply the boost and update the second reference frame then set the frame data rate target to the baseline value+Boost % and calculate and the interval until the next update based upon MotionSpeed.
If the decision is made not to apply the boost and not to update the second reference frame, then update the frame as normal with a 0% data rate boost.
Else if a second reference frame update is not due, calculate a reduced frame data rate target (negative boost) that takes into account the level of boost applied when the second reference frame was last updated and the current update interval.
Using a Reconstruction Error Metric to Select Between Alternative Methods for Creating Fractional Pixel Predictions
Many modern video codecs support prediction of motion to sub pixel accuracy. For example half pixel or quarter pixel motion estimation. To create fractional pixel data points it is necessary to use some form of interpolation function or filter applied to real (i.e., full pixel aligned) data points.
Early codecs generally used simple bilinear interpolation.
A
x
y
z
C
In this example A, B, C, and D are full pixel aligned data points and x,y and z are half pixel aligned points.
Point x is half pixel aligned in the X direction and would be calculated using the formula (A+B/2).
Point y is half pixel aligned in the Y direction and would be calculated using the formula (A+C/2).
Point z is half pixel aligned in both X and Y would be calculated using the formula (A+B+C+D /2) .
Later codecs have tended to move towards the use of more complex interpolation filters such as bicubic filters, that are less inclined to blur the image. In the following example ‘x’ is a half pixel point that lies half way between two full pixel aligned pointes B and C. It can be calculated using the formula (−A+9B+9C−D)/16.
A B×C D
Though filters such as the one illustrated above tend to produce sharper results, repeated application over several frames can sometimes result in unpleasant artifacts such as exaggeration of textures or false contouring.
This aspect of the invention is a method where by a codec can use a mixture of bilinear and bicubic filtering to calculate more optimal fractional pixel predictors and select between these methods either at a frame level or at the level of the individual blocks or regions to which motion vectors are applied.
Selection at the block or region level could be achieved by means of signalling bits within the bitstream, but in the preferred implementation selection is made by means of a complexity metric applied to the set of pixels in the previous reconstructed image that are going to be filtered.
According to this method, blocks or regions with a complexity score above a threshold value “T” are filtered using the bicubic method whilst those with a lower complexity score are filtered using the bilinear method.
In the preferred implementation the complexity metric is the variance of the set of “n” full pixel aligned data points to be filtered, where variance is defined as:
(nEx 2 −(Ex) 2 )/n 2 . (5)
In the preferred implementation the threshold value T′ may be updated on a once per frame basis.
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A system, apparatus, and method of compressing video data having at least one frame having at least one block having an array of pixels. The method includes transforming the pixels of the at least one block into coefficients, creating a default transmission order of the coefficients, creating an optimal transmission order of the coefficients, comparing a coefficient position of at least one of the coefficients in the optimal transmission order with a coefficient position of the at least one of the coefficients in the default transmission order; determining an update value based on the comparison, and selectively encoding position information of the at least one of the coefficients in the optimal transmission order based on the update value.
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This application is a continuation-in-part of U.S. Ser. No. 665,827, filed Oct. 29, 1984, now U.S. Pat. No. 4,596,547.
FIELD OF THE INVENTION
This invention relates to the field of treating cells with photoactivatable compounds and radiation which activates the compound thereby affecting the cells and specifically, relates to clinically useful systems for the extracorporeal treatment of blood cells, especially leukocytes, with UV radiation and more particularly with automated, manual overridable valves therefor.
BACKGROUND OF THE INVENTION
It is well-known that a number of human disease states may be characterized by the overproduction of certain types of leukocytes, including lymphocytes, in comparison to other populations of cells which normally comprise whole blood. Excessive or abnormal lymphocyte populations result in numerous adverse effects to patients including the functional impairment of bodily organs, leukocyte mediated autoimmune diseases and leukemia related disorders many of which often ultimately result in fatality.
U.S. Pat. Nos. 4,321,919; 4,398,906; 4,428,744; and 4,464,166 to Edelson describe methods for treating blood whereby the operation or viability of certain cellular populations may be moderated thereby providing relief for these patients. In general, the methods comprise treating the blood with a dissolved photoactivatable drug, such as psoralen, which is capable of forming photoadducts with DNA in the presence of U.V. radiation. It is believed that covalent bonding results between the psoralen and the lymphocyte nucleic acid thereby effecting metabolic inhibition of the thusly treated cells. Following extracorporeal radiation, the cells are returned to the patient where they are through to be cleared by natural processes but at an accelerated pace believed attributable to disruption of membrane integrity, alteration of DNA within the cell, or the like conditions often associated with substantial loss of cellular effectiveness or viability.
Although a number of photoactivatable compounds in the psoralen class are known, 8-methoxy psoralen is presently the compound of choice. An effective radiation for this compound, and many psoralens in general, is the ultraviolet spectrum in the range of approximately 320 to 400 nanometers, alternatively referred to as the U.V.A. spectrum. As the development of photoactivatable compounds proceeds, it may be expected that changes in the preferred activation radiation spectrum will be necessary. Suitable selection of radiation sources will, of course, increase treatment efficiency and is contemplated as an obvious optimation procedure for use with the inventions disclosed herein.
Although Edelson's methods have been experimentally shown to provide great relief to patients suffering from leukocyte mediated diseases, numerous practical problems require solutions. In particular, Edelson fails to provide a suitable apparatus for applying radiation to the cells, e.g. via a treatment station, in an economical and efficacious manner, or a system for incorporating a treatment station providing for the treatment of a patient in a clinically acceptable format.
Conventional techniques for photoactivating compounds associated with cells have relied on a plurality of devices including flasks, filtration columns, spectrophotometer cuvettes, and petri dishes. The sample to be irradiated is added to the containers and the container placed adjacent to the radiation source. Such systems tend to be laboratory curiosities as they fail to provide the necessary safeguards intrinsically necessary where patient bodily fluids are concerned, particularly since these fluids must be returned to the patient thereby necessitating strict avoidance of contamination. Further, such methods tend to be volume limited, are characterized by many mechanical manipulations and are generally unacceptable from a clinical and regulatory viewpoint. It is an object of the present invention to provide methods and apparatus suitable for use with the Edelson methods to overcome the limitations associated with the conventional expedients.
Copending application U.S. Ser. No. 650,602, describes a practical device for coupling the radiation provided by commercially available light sources, such as the so-called "black-light" fluorescent tubes, to cells for treatment by Edelson's photoactivated drug methods. In summary, the disposable cassette described therein comprises a plurality of fluorescent tube-like light sources such as the U.V.A. emitting Sylvania F8TS/BLB bulb, which are individually, coaxially mounted in tubes of larger diameter which are, in turn, coaxially mounted in sealing arrangement within second outer tubes of even larger diameter thereby forming a structure having two generally elongated, cylindrical cavities about each radiation source. The inner cavity preferably communicates with the atmosphere thereby facilitating cooling of the radiation source. The second tube forming the outer cavity further comprises inlet and outlet means for receiving and discharging, respectively, the cells to be irradiated. A plurality of these structures are "ganged" and suitable connections made between inlets and outlets of adjacent members to provide for serpentine flow of cells through each outer cavity. Thus, continuous flow of the cells through the plurality of cavities surrounding the centrally disposed radiation sources facilitates thorough treatment of the cells. Additional, detailed description of the Taylor device may be obtained by direct reference to U.S. Ser. No. 650,602.
To be fully practical, the Taylor device requires a clinically acceptable instrument to house the device and to provide the cells to be treated in an appropriate form. Such an instrument is the object of the inventions described in U.S. Pat. Nos. 4,573,960, 4,568,328, 4,578,056, 4,573,961, 4,596,547, 4,623,328 and 4,573,962, fully incorporated herein by reference. While the instruments described therein work well, it is an object of the instant application to describe improved systems capable of implementing, in advanced fashion, the medical treatment principles first taught by Edelson.
It is another object of the present invention to provide still further improvements in greater patient safety and comfort while reducing treatment time and cost, by utilizing a newly designed disposable irradiation chamber in an appropriate instrument which incorporates a photoactivating light array, more fully described in copending applications U.S. Ser. No. 834,258 and U.S. Ser. No. 834,256, respectively.
It is yet another object to provide an improved instrument which meets the above criteria along with all the positive attributes of the prior system; compactness, mobility, completeness, fully automated and monitored, coupled with ease of operation.
It is a further related object of this invention to provide, in contrast to the time consuming batch like processing of the prior system, continuous on-line patient treatment wherein collection, separation, and cell treatment occur simultaneously, thereby reducing treatment time and increasing patient safety and comfort.
BRIEF DESCRIPTION OF THE DRAWINGS
These and still other objects of the invention will become apparent upon study of the accompanying drawings wherein:
FIG. 1 illustrates a preferred configuration of the system during collection, separation, and treatment;
FIG. 2 shows a preferred embodiment of the flat plate irradiation chamber, recirculation pump, and photoactivating light source array;
FIG. 3 shows a bottom view of the structures of FIG. 2;
FIG. series 4 shows a pivoting "or" valve of the present invention;
FIG. series 5 shows a pivoting "on/off" valve of the present invention;
SUMMARY OF THE INVENTION
In accordance with the principles and objects of the present invention there are provided apparatus for "on-line" extracorporeally photoactivating a photoactivatable reagent in contact with blood cells by collecting and separating on a continuous basis, blood from a patient while the patient is connected to the apparatus, returning undesired blood portions obtained during separation while the desired portion is photoactivatably treated whereupon the thusly treated cells are returned to the patient. As a result of this novel approach, the treatment system of the instant inventions optimizes and minimizes treatment time by concurrently conducting various aspects of such photoactivation treatment which were previously performed sequentially. More specifically, the apparatus collects and separates blood on a continuous basis as it is withdrawn from the patient and returns unwanted portions to the patient while concurrently energizing the irradiation sources for photoactivating the photoactivatable reagent in contact with the desired blood portion. Following photoactivation, the treated cells may then be facilely returned to the patient utilizing a drip chamber gravity feed infusion line incorporated in the tubing set. As will be readily apparent, the system of the instant invention requires a tubing set connecting the patient to the system and for conveying various blood portions to specified areas for manipulation. Fluid flow control is accomplished by new valve mechanisms which are the particular subject of this invention. These valve mechanisms are servo controlled but manually overridable.
DETAILED DESCRIPTION
FIG. 1 shows various aspects of the system developed for extracorporeally treating a patient based in part upon the scientific discoveries of Edelson. While the specific design, construction and operation of the apparatus 10 is the result of a number of separate inventions some of which form the subject matter of previously described issued patents and copending commonly assigned applications including U.S. Ser. No. 834,292 entitled "Concurrent On-Line Irradiation Treatment Process"; U.S. Ser. No. 834,293 entitled "Electronic Device For Authenticating And Verifying Disposable Elements"; U.S. Ser. No. 834,294 entitled "Disposable Temperature Probe For Photoactivation Patient Treatment System"; U.S. Ser. No. 834,256 entitled "Light Array Assembly For Photoactivation Patient Treatment System"; U.S. Ser. No. 834,257 entitled "Pump Block for Interfacing Irradiation Chamber to Photoactivation Patient Treatment System"; U.S. Ser. No. 834,260 entitled "Demountable Peristaltic Pump For Photoactivation Patient Treatment System"; U.S. Ser. No. 834,259 entitled "Zero Insertion Force Socket For Photoactivation Patient Treatment System" and U.S. Ser. No. 834,258 entitled "Irradiation Chamber For Photoactivation Patient Treatment System", the relevant parts of which are fully incorporated herein by reference, nonetheless it is believed a brief description may be helpful.
The operation of the device and performance of the methods can be divided into two basic phases or modes, depicted in part by FIG. 1. The first phase is shown substantially in FIG. 1 wherein the patient is connected at the point shown, preferably by venipuncture or the like methods well-known and developed to a high degree in the dialysis arts. Patient blood, as it flows to the apparatus 10 (alternately referred to herein as the photopheresis apparatus or system) is preferably infused, under control of pump 11, with an anticoagulant agent contained in container 20 hung from stand 15. Control of the flow of patient blood to the remainder of apparatus 10 is controlled largely by clamping means 16a which has the dual function of also controlling flow in the reverse direction as well as flow to return container 21. Clamp 16a acts as an "or" valve and will be described in greater detail later.
Normally the blood flows through tubing 24 through blood pump 12 (preferably a roller pump such as that described in U.S. Pat. No. 4,487,558 to Troutner entitled "Improved Peristaltic Pump" and incorporated herein by reference) into continuous centrifuge 13. This continuous centrifuge, available commercially from suppliers such as Dideco, Haemonetics and others, is preferably capable of continuously separating blood based on the differing densities of the individual blood components. "Continuously", as used herein means that, as blood flows into the centrifuge through line 24, it accumulates within the rotating centrifuge bowl and is separated so that low density components are emitted after a certain minimum volume has been reached within the centrifuge bowl and as additional blood is added. Thus, the continuous centrifuge in effect acts as a hybrid between a pure online system and a pure batch system. This occurs because the centrifuge bowl has a capacity to hold most, if not all, of the most dense portion, typically erythrocytes or red blood cells while emitting lower density portions such as plasma and leukocytes (white blood cells) as whole blood is continuously added. At some point, however, the reservoir volume of the centrifuge is filled with the higher density components and further separation cannot be effectively obtained. Prior to that point, the operator, by viewing the uppermost portion of the centrifuge bowl through the centrifuge cover, can detect qualitatively when the centrifuge emits plasma (as opposed to priming solution), leukocyte enriched portions and the remainder, i.e., nonleukocyte enriched portions, including erythrocyte enriched portions. Based on the operator's observations, he or she enters through control panel 19 the identification of the individual blood portions as they are emitted from the centrifuge. This information is entered by keys 44 (e.g. PLASMA, BUFFY COAT or leukocyte enriched portion) on control panel 19, and in response thereto, the apparatus 10 controls valve mechanism 16c to direct the leukocyte enriched portion and a predetermined volume of plasma into plasma-leukocyte enriched container 22 while excess plasma, air, priming fluids, erythrocytes etc. are directed to container 21.
Once the centrifuge is no longer capable of further separation due to the attainment of its capacity, the operator directs that the bowl be emptied by suitable data key entry on panel 19 and the fluid contents of centrifuge 13 are advantageously pumped into return container 21 by means of pump 12 under the control of valves 16a and c. The foregoing steps may be repeated a number of times or cycles before the desired volume of leukocyte enriched blood and plasma is obtained for further treatment, in each instance the undesired portions being collected in return container 21.
Between cycles, the fluids, including erythrocytes which have been pumped into return bag 21 are gravity fed back to the patient through a drip infusion operation and controlled by valve 16b. It is preferred that gravity feed be employed rather than pumping the blood back to the patient via pump 12 in order to avoid potential pressurization problems at the infusion insertion site at the patient, and also to avoid foaming or other air related dangers.
As may be already appreciated, when initially set up, the centrifuge bowl and line 24 may be expected to contain sterilized air which is preferably removed by suitable priming operations advantageously accomplished by utilizing the anticoagulation agent in container 20; both the air and a portion of priming solution being collected in container 21.
Also to be noted is the predetermination of the desired leukocyte enriched volumes and plasma volume to be collected within container 22 as well as the number of cycles to be employed to collect same. These volumes are selected largely in accordance with the individual volume capacities of the containers as well as the treatment irradiation chamber to be described later. Accordingly, these volumes are set in order to preferably optimize handling efficiency and to ensure patient safety. For instance, one preferred selection would include the following settings: 250 ml total buffy coat or leukocyte enriched portion and 300 ml of plasma to be collected within container 22. This might require any number of cycles, preferably on the order of three or four, bearing in mind that the more cycles that are selected, the lower the total volume of blood withdrawn from the patient at any one time. If blood collection meets the minimum capacity limits of the centrifuge bowl, the patient's capacity to withstand temporary blood volume depletions and the treatment procedure in general is increased.
Further, more cycles will permit more discriminating selection of leukocyte enriched blood as it is emitted from the centrifuge. The buffy coat and plasma volumes as well as the number of cycles are typically physician selected. Accordingly, the controls governing these selections are preferably placed within the apparatus 10, such as behind door 18a where their inadvertent alteration may be advantageously avoided, especially since no operator interaction is normally required with respect to these data inputs.
The leukocyte enriched container 22 is connected via tubing line 34 to the flat plate treatment chamber behind chamber assembly door 17 with a return line 35 to reservoir container 22.
The leukocyte enriched blood, plasma, and priming solution contained in reservoir 22 is delivered through line 34 to the inlet of the flat plate irradiation chamber 200, upward through the flat plate cavity in the chamber to the outlet. Tubing from the outlet passes through a pump block, affixed to the end of the flat plate irradiation chamber, and then connects to return line 35 which returns fluids from the chamber to container 22. A recirculation roller pump-type rotor, located internally in the machine, engages the tubing in the pump block in the semi-circular tract and thereby provides and controls the recirculating flow of fluid from container 22 up through the flat plate irradiation chamber and back to container 22. The tubing line associated with the flat plate irradiator preferably incorporates a thermocouple for monitoring the fluid temperature.
Sterile air, initially contained in the irradiation chamber cavity is advantageously displaced by entering fluid and stored in the top portion of container 22. By reversing the rotation of recirculation roller pump rotor, the air stored in container 22 can be pumped back into the outlet of the irradiation chamber thereby displacing all fluids back into container 22. When the irradiation chamber is fluid filled and the BUFFY COAT button on panel 19 is pressed, the light array assembly which surrounds the chamber is energized. Continued operation of the recirculation roller pump rotor results in recirculation of the leukocyte enriched fluid from container 22 through the chamber and the energized light array assembly and back to container 22. Thus, the photoactivating irradiation of the leukocyte enriched fluid is initiated at the outset and continues through and after the collection and separation process.
The flat plate irradiation chamber treatment element is described in greater detail in copending application U.S. Ser. No. 834,258, which is fully incorporated herein by reference.
In operation, the exposure time is set via panel 19 in accordance with physician determined criteria. The central control means of the apparatus 10 calculates and displays via central processing unit and memory stored software, the exposure time remaining at the onset of irradiation treatment and as the treatment progresses. Another portion of the control panel 19 also preferably includes three operator controlled entry data keys whereby the operator can de-energize the light array and stop the recirculation process if desired. Actual photoirradiation treatment commences automatically under control of the central processing unit when fluid is first directed to container 22. The leukocyte enriched portion of the blood collected within container 22, is pumped through tubing set 34, through the treatment cassette, through return line 35, and back into reservoir 22. This continues until the preset exposure time has expired whereupon the light array is de-energized and the recirculation roller pump reverses emptying the contents of the irradiation cassette into container 22.
Thereafter container 22 is ideally removed to stand 15 where it is connected to tube 36 provided on the drip chamber 21a, associated with return container 21, for reinfusion of the treated blood portion into the patient.
To further decrease the risk of contamination to the patient blood and blood portions, each time a connection is made or broken, it is preferably only done once. Thus, container 22 would ideally have four connection points or ports; one for the collection of the leukocyte enriched blood portion, two for connection to the flat plate irradiation cassette, and the fourth for connection to the drip chamber for reinfusion of treated blood to the patient.
The control panel 19 of the apparatus 10 is shown with the keyboard entry buttons 44, each ideally having a light which, when lit, preferably indicates the stage of the operation. As will be noted, the keyboard entry buttons 44 are preferably placed in sequential order thereby assisting the operator in learning the system and performing the steps in the correct order. Indeed, the central control microprocessor will preferably be programmed to prevent out of step sequences from being implemented. A visual display indicates the volume of leukocyte enriched blood collected in container 22.
Panel 19 will preferably also contain a power switch, as well as a blood pump speed control whereby the operator may select the speed with which the blood is withdrawn from the patient and pumped through the system during collection. Also preferably included is an alpha-numeric display for indicating the machine's status and identifying alarm conditions throughout system operation. Optional accessory status lights, preferably provided in green, yellow, and red colors, provide at a glance the overall operating status of apparatus 10. Further included is a mute reset button for quieting an audible alarm activated in the event an alarm condition occurs and operator input is required.
Other features may be readily apparent from the drawings such as the preferable inclusion of casters and caster brakes for enhancing the mobility of the apparatus. Further, side panel 23 will preferably include mechanical means (e.g. hanging pegs and the like) for assisting in the securement of container 22. It may also optionally be outfitted with a transparent or translucent opening 18b in the area beneath container 22 for providing at a glance information regarding the illumination status of the irradiation treatment cassette during the treatment phase. For instance, if the window is of sufficient size, the operator may readily determine that each irradiation source within the treatment cassette is illuminated as desired. Naturally, the material comprising such window is preferably selected in order to contain harmful radiation, if any, within apparatus 10.
The aforedescribed photopheresis blood treatment apparatus is made largely possible by an automated control method for directing the blood portions, derived from the continuous centrifuge, into particular containers. The automated method performs in accordance with preset volume determinations which are manually entered behind panel 18a pursuant to a physician's direction. These predetermined volumes specify the volume to be contained within container 22 by setting forth the volume of plasma and the volume of leukocyte enriched blood portion to be directed thereto. Additionally included within these condition setting parameters is preferably the ability to set forth the number of cycles of blood collection and separation required or desired in order to obtain the desired blood volumes.
The volumes collected are determined in accordance with the blood volume pumped by the blood pump. This may be suitably monitored and communicated to the central control means by specifically monitoring the number of step pulses input to the pump to cause rotation of the blood pump. Typically, 200 pulses results in one revolution. Rotation may also be conveniently monitored such as by attachment of a slotted disk to the shaft and the passage of slots determined by an optical sensor means such as described in U.S. Pat. No. 4,623,328 (fully incorporated herein) and by monitoring shaft rotation. The resultant periodic signal may be conveniently correlated with speed and number of rotations by circuit designs well-known in the art. The number of rotations by any of the foregoing methods coupled "with the known volume pumping characteristics of the pump", will provide the necessary information regarding the volume of blood pumped. It will readily be appreciated that the sensors need not be optical but may be electronic or mechanical instead.
In actual operation, a most preferred procedure would be as follows. The operator presses the PRIME CENT. key on control panel section 19 which primes the tubing set, the blood pump, and the centrifuge with the anticoagulation solution contained in container 20. Displaced sterile air is collected in container 21. When priming solution emerges from the exit of the centrifuge, the operator presses PRIME UV key on control panel section 42 which closes the tubing line to container 21 and opens the tubing line to container 22 by means of valve 16c. Recirculation roller pump rotor 203 is energized to prime the flat plate irradiation chamber and collect displaced sterile air in container 22. The priming process stops automatically after a preset volume of fluid is delivered to container 22.
Blood collection is started by the operator pressing START key on control panel section 19. Thereafter, blood is withdrawn from the patient and pumped by the blood pump into the rotating centrifuge. As the blood enters the centrifuge, it displaces the priming solution which emerges first in accordance with its preferably lighter density. This priming solution is automatically directed into container 22 until a preset volume is delivered, after which the emerging solution is redirected to container 21 by means of valve 16c. At some point, the priming solution will be completely displaced from the rotating centrifuge and plasma will begin to emerge. This emergence may be directly observed through port 14 whereupon the operator presses the PLASMA key on control panel section 19. Thereafter, the central control means automatically directs the plasma into container 22 by altering valve 16c keeping track of the volume as it does so since the volume entering the centrifuge equals the volume emerging therefrom. This continues until the operator indicates the leukocyte enriched portion, i.e. buffy coat has begun by pressing the respective data entry key in control panel section 42 whereupon, the leukocyte enriched portion continues to container 22, however, the volume so directed is monitored as buffy coat volume. Alternatively, if all of the predetermined plasma volume is collected prior to the emergence of the buffy coat, then the central control means automatically diverts, by valve 16c, the emerging plasma fluid stream to container 21. In that instance, upon the emergence of the buffy coat and the keying of the BUFFY COAT data entry switch 44, the central control means diverts the emerging buffy coat into container 22 by means of valve 16c, again keeping track of its volume.
The collection of the buffy coat will preferably continue in accordance with both the predetermined buffy coat volume as well as the number of cycles, another condition predetermined by the physician. If this most preferred embodiment is employed, then a representative example might be as follows. Assume, that the predetermined volume and cycle conditions are set as follows: 350 mls of plasma, 250 mls of buffy coat, and 5 cycles. In each cycle, the apparatus will collect 250/5 or 50 mls of buffy coat before ending the cycle and thereupon emptying the centrifuge bowl and returning all nonleukocyte fluids, predominantly erythrocytes and perhaps excess plasma, to the patient. Prior to the collection of the 50 mls, plasma will emerge from the centrifuge and will be collected in container 22 either until the full 350 mls are collected or, until the buffy coat emerges.
During the next cycle, the central control means will direct the further collection of plasma, if needed, in order to reach the 350 ml predetermined volume and then collect an additional 50 mls of buffy coat. The total volume to be contained within container 22, will then equal 600 mls and would be indicated on display 46 as it is accumulated.
Thus, the instant invention serves to automatically keep track of the volumes as they are collected thereby facilitating the institution of a convenient number of cycles whereby the removal of large blood volumes from the patient is avoided. Not only is patient safety enhanced thereby, but the automated nature of the procedure further increases safety since, in accordance with the programmed conditions supplied to the central control microprocessor, the operator need not attempt to keep track of plasma and leukocyte enriched volumes collected, while still being assured that the final solution for treatment will contain the predetermined and desirable leukocyte concentration.
The foregoing described automated methods used in the photopheresis apparatus described with respect to FIG. 1 depends heavily upon the instant inventions for controlling fluid flow, in particular servo controlled valve mechanisms which may be manually overridden without disengaging the servo control means. These mechanisms are shown in Figure series 4 and 5 which describe the valve arrangements 16a, 16b, and 16c.
With specific reference to FIGS. 4a and b, depicted are top and side views of a pivoting "or" valve shown in FIG. 1 as 16a. Tubing portion 111 is connected to the patient and leads alternately to tubing 112 connected to the return container 21 (FIG. 1) and to tubing 110 which leads toward the blood pump 12 (FIG. 1). The tubing sections 111 and 112 rest against block means 116 which is fixedly mounted on work surface 117. Clamping means 130 is mounted on rotatable shaft 122 extending through bearing 125 which is mounted in fixed block 116. Clamp edges 113b and 114b operate alternately to squeeze tubing sections 111 and 112 respectively against fixed post or anvils 113a and 114a respectively. When activated, the respective clamping edges will preferably pinch the lines into full occlusion or permit free flow. Motion translator 115 is affixed to shaft 122. Actuator shaft 121 is pivotally mounted to the opposite end of the motion translator 115 by pivot means 123. Actuator shaft 121 is additionally attached to linear actuator stepper motor 120. Thus, inward and outward forces exerted by linear actuator stepper motor 120 are transmitted to clamp means 113 and 114 respectively. The clamp will optionally include slotted plates 118A and 118B, affixed to block 116, for advantageously retaining tubing 111 and 112 respectively in position for clamping.
As may be readily apparent, a manual override feature is desirable in order to facilitate the mounting and unmounting of tubing sets. The means for engaging and disengaging shaft 122 and clamping means 130 is shown in top view in FIG. 4C, and cut-away side view in FIGS. 4D and 4E. Shaft 122 is affixed to hollow cylindrical pivot block 126 which can rotate within cylindrical sleeve 127. Sleeve 127 is firmly affixed to clamping means 130. One or more juxtaposed holes 128a and 128b in sleeve 127 and pivot block 126 respectively, contain hard steel ball(s) 129. Also contained within the hollow pivot block 126 is plunger 131 having a narrow diameter portion 131a and a wide diameter portion 131b, and guide rod 131c. Compression spring 132 biases plunger 131 in an upward direction whereupon the wide diameter portion 131b aligns with balls 129 causing the balls 129 to enter holes 128a. In this position, shown in FIG. 4D, the balls 129 securely lock pivot block 126 together with sleeve 127 and all forces generated by linear actuator stepper motor 120 are transmitted through shaft 122 to clamp means 113 and 114. For operator comfort, button 133 is affixed to the extension of plunger 131. When button 133 is pressed, the plunger 131 moves downward against spring 132 until the narrow diameter 131a aligns with balls 129 allowing the balls 129 to move inward and exit holes 128a in sleeve 127. In this position, shown in FIG. 4E, the pivot block 126 is no longer locked to sleeve 127 and clamping means 130 is free to rotate. It is thus readily apparent that pressing button 133 will disengage the clamp from the actuator and permit easy installation or removal of tubing sets.
FIG. series 5 shows an "on/off" valve employed as valve 16b for controlling return flow from container 12 to the patient as well as for preventing inadvertent flow into container 21. As in FIG. series 4, the servo actuator motor 120 actuator shaft 121, and motion translator 115 are substantially the same although obvious mechanical variations may be substituted. In the "on/off" valve, however, although clamping means 140 and fixed block means 145 is rectangularly shaped rather than triangularly shaped, as in the FIG. 4 "or" valve, clamping edge 141b pinches line 143 against anvil 141a in a similar manner.
The disengaging mechanism shown in FIGS. 4C, 4D, and 4E may be identically used in the FIG. 5 on/off valve.
Upon study of the accompanying figures, and the foregoing description, it will become readily apparent to the skilled artisan that numerous alterations may be made to the foregoing without departing from either the spirit or scope of the instant invention.
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Manually overridable servo controlled valve mechanisms for controlling the flow of fluids through a flexible tube for use in a photoactivatable agent treatment system wherein photoactivatable agents, in contact with patient blood cells, are irradiated extracorporeally and then returned to the patient.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to an apparatus for use in adsorption and desorption based sorption heat pump processes.
[0002] Sorption heat pump processes typically employ some adsorbent disposed in a metal vessel and on a metal screen or surface which provides support for the adsorbent and permits the adsorbent to be placed in contact with the fluid stream containing the adsorbable component over the range of conditions necessary for the adsorption and desorption. The metal structures and physical arrangement of these devices has placed certain process limitations which restrict the amount of adsorbent which actually comes in contact with the fluid stream, or is accompanied by heat transfer inefficiencies inherent in the disposition of the adsorbent.
[0003] In the operation of sorption heat pump systems, generally there are two or more solid beds containing a solid adsorbent. The solid adsorbent beds desorb refrigerant when heated and adsorb refrigerant vapor when cooled. In this manner the beds can be used to drive the refrigerant around a heat pump system to heat or cool another fluid such as a process stream or to provide space heating or cooling. In the heat pump system, commonly referred to as the heat pump loop, or a sorption refrigeration circuit, the refrigerant is desorbed from a first bed as it is heated to drive the refrigerant out of the first bed and the refrigerant vapor is conveyed to a condenser. In the condenser, the refrigerant vapor is cooled and condensed. The refrigerant condensate is then expanded to a lower pressure through an expansion valve and the low pressure condensate passes to an evaporator where the low pressure condensate is heat exchanged with the process stream or space to be conditioned to revaporize the condensate. When further heating no longer produces desorbed refrigerant from the first bed, the first bed is isolated and allowed to return to the adsorption conditions. When the adsorption conditions are established in the first bed, the refrigerant vapor from the evaporator is reintroduced to the first bed to complete the cycle. Generally two or more solid adsorbent beds are employed in a typical cycle wherein one bed is heated during the desorption stroke and the other bed is cooled during the adsorption stroke. The time for the completion of a full cycle of adsorption and desorption is known as the “cycle time.” The upper and lower temperatures will vary depending upon the selection of the refrigerant fluid and the adsorbent. Some thermodynamic processes for cooling and heating by adsorption of a refrigerating fluid on a solid adsorbent use zeolite and other sorption materials such as activated carbon and silica gel. U.S. Pat. No. 4,138,850 relates to a system for solar heat utilization employing a solid zeolite adsorbent mixed with a binder, pressed, and sintered into divider panels and hermetically sealed in containers. U.S. Pat. No. 4,637,218 relates to a heat pump system using zeolites as the solid adsorbent and water as the refrigerant wherein the zeolite is sliced into bricks or pressed into a desired configuration to establish a hermetically sealed space and thereby set up the propagation of a temperature front, or thermal wave through the adsorbent bed. U.S. Pat. No. 5,477,705 discloses an apparatus for refrigeration employing a compartmentalized reactor and alternate circulation of hot and cold fluids to create a thermal wave which passes through the compartments containing a solid adsorbent to desorb and adsorb a refrigerant. U.S. Pat. No. 4,548,046 relates to an apparatus for cooling or heating by adsorption of a refrigerating fluid on a solid adsorbent. The operations employ a plurality of tubes provided with parallel radial fins, the spaces between which are filled or covered with solid adsorbent such as Zeolite 13X located on the outside of the tubes. U.S. Pat. No. 5,518,977, which is hereby incorporated by reference, relates to sorption cooling devices which employ adsorbent coated surfaces to obtain a high cooling coefficient of performance.
[0004] U.S. Pat. No. 5,585,145 discloses a method for providing an adsorbent coating on a heat exchanger which comprises applying a flowable emulsion including a binder agent, water and a solid adsorbent material to the surface of the heat exchanger. The disclosure states that the binder can be an adhesive and that the thickness of the adsorbent coating can be dipped, painted or sprayed with a drying step comprising heating the layer at temperatures greater than 150° C. in order to obtain a durable adsorbent coating structure.
[0005] Many sorption chillers are designed with beads or extrudate as an adsorbent. In the present invention, as in U.S. Pat. No. 6,102,107, there are no beads or extrudates with their resistance to heat transfer, but instead there is a compact heat exchanger module that comprises a laminate of adsorbent, especially zeolite, in a polymeric or polymeric fiber matrix. This laminate is on a substrate that can support the laminate and can be employed in the hot and wet environment of the adsorber/generator.
[0006] U.S. Pat. No. 6,102,107, incorporated herein in its entirety, teaches the use of a plate-fin-tube arrangement employing a laminate composed of thin polymeric fiber matrix on a metallic fin structure. Conventional tubing is laced through the fms by punching holes in the fin structure and forming collars of the fm metal that are maintained in intimate thermal contact with the tube surfaces. While this patent provided for greatly increased heat transfer and was a significant advance in the design and performance of adsorber/generators in sorption based heat pumps, it failed to deal with the problem of maximizing heat transfer when materials other than high thermal conductivity fin plates are used.
[0007] In addition to the problem of heat transfer resistance in some materials, a second potential problem arises when clean, uncoated aluminum is exposed to water vapor under vacuum conditions. This is the problem of corrosion of the aluminum surface and formation of AlOH radicals on the surface. This reaction liberates hydrogen gas and is a cause for the loss of vacuum under some conditions that may be present in the adsorber/generator of a sorption cooler or heat pump. Stainless steel could be used to solve this deficiency, but the low conductivity of stainless steel changes the heat transfer resistance. This makes adsorber/generators made from stainless steel incapable of transferring the required heat and can result in structures that are much more costly and only slightly more efficient than packed bed systems. One feature of the present invention is to allow for the use of aluminum with its superior heat transfer properties but without the corrosion problems of the prior art heat exchangers.
[0008] It is an object of the instant invention to provide an improved compact heat exchanger with the adsorbent matrix bonded directly to the plates. It is a further object of the invention to enable the application of a thin uniform layer of adsorbent material which is intimately bonded to a heat transfer surface. Another object of the present invention is to enable a rapid heating and cooling cycle with the purpose of achieving a high specific power and a high coefficient of performance for the sorption cooling cycle. Yet another object of the present invention is to provide a heat exchanger geometry that is effective regardless of the heat conductivity of the fin material that is chosen.
SUMMARY OF THE INVENTION
[0009] The present invention relates to a highly efficient sorption heat pump module apparatus for use in sorption heat pump processes which can be used effectively with a rapid cooling and heating cycle. A sorption heat pump exchanger module is employed comprising a plurality of metallic plates having a first and a second opposing side and an adsorbent coating covering essentially the entire surface of said first opposing side and wherein a first and a second of said metallic plates are grouped together to form a sub-unit having a passageway between said two metallic plates for passage of a heat exchange media and wherein a plurality of said sub-units are spaced apart in a stacked arrangement that eliminates contact between said sub-units; a plurality of tubes contacting said sub-units wherein a heat exchange medium flows within said tubes to and from openings in said tubes to openings in said sub-units, and a passageway between each of said sub-units wherein a refrigerant flows within said passageway.
[0010] In some embodiments of the invention, it has been found that the use of metallic plates comprising a corrosion resistant aluminum such as anodized aluminum provides for a highly efficient heat exchanger that withstands corrosion. More specifically, the sorption heat pump exchanger module comprises a plurality of anodized aluminum fin plates having a first and second opposing sides and an adsorbent coating comprising at least one adsorbent selected from the group consisting of zeolite X, Zeolite Y, Zeolite A, silica gel, silicas, aluminas and mixtures thereof. The adsorbent coating covers essentially the entire surface of each opposing side to form coated fin plates and the fin plates are spaced apart in a stacked arrangement that eliminates adsorbent bridging between all coated surfaces. There are at least 300 coated fin plates for every meter of the stacked arrangement. A plurality of tubes extend through openings in the fin plates wherein the outside of the plurality of tubes directly contacts the periphery of the openings to form the sorption heat pump exchanger module defining a first flow path for a heat exchange medium in the plurality of tubes and a second flow path for a refrigerant between said coated fin plates.
[0011] In another embodiment of the present invention, a sorption heat pump exchanger module comprises a plurality of anodized aluminum fin plates having a first and second opposing sides and an adsorbent coating covering essentially the entire surface of each opposing side. There are a plurality of openings defined by the anodized aluminum fin plates and extending through the anodized aluminum fin plates and coating. A plurality of tubes that have uncoated outer walls extend transversely through the anodized aluminum fin plates and have direct contact with the anodized aluminum fin plates being spaced apart in a stacked arrangement that eliminates adsorbent bridging between all coated surfaces and contain at least 300 anodized aluminum fin plates for every meter of the stacked arrangement. The plurality of tubes extend through the openings in the anodized aluminum fin plates wherein the outside of said plurality of tubes directly contact the periphery of the openings to form the sorption heat pump exchanger module defining a first flow path for a heat exchange medium in said plurality of tubes and a second flow path for a refrigerant between said coated anodized aluminum fin plates. The adsorbent is selected from the group consisting of Zeolite X, Zeolite Y, Zeolite A, silica gel, silicas, aluminas and mixtures thereof.
[0012] In yet other embodiments of the present invention, the sorption heat pump exchanger module comprises a plurality of fin plates, having a first side and a second side opposite said first side wherein said fin plates are approximately rectangular in shape. The fin plates have two long edges and two short edges. An adsorbent coating covers a majority of the first side and the second side, except where there is a gap in the adsorbent coating extending from one of the long edges to the other of the long edges. The fm plates are bent along the gaps to form a corrugated structure and the fin plates contact a top and a bottom outside surface of a pair of parallel heat transfer passages. This structure has been found to have highly effective heat transfer properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a view of a single-sided laminate of a zeolite-containing matrix bonded to a substrate.
[0014] [0014]FIG. 2 is a cross-sectional view of a pair of single-sided laminates mated together with a heat transfer channel between the two laminates.
[0015] [0015]FIG. 3 shows a view of the heat transfer passageway between two layers of the laminate of the present invention.
[0016] [0016]FIG. 4 shows an assembly of repeating units of the units shown in FIG. 3.
[0017] [0017]FIG. 5 shows a double-sided laminate of a zeolite-containing matrix bonded to both sides of a substrate.
[0018] [0018]FIG. 6 shows an embodiment of the invention having gaps in the lamination to allow for bonding of a surface to an adjacent heat transfer passage.
[0019] [0019]FIG. 7 shows how the uncoated gaps in the structure shown in FIG. 6 are mated to the outside of heat transfer surfaces.
[0020] [0020]FIG. 8 shows a combination of the heat transfer passage assembly of FIG. 4 with the addition of fm stock bonded to the outside surfaces of the heat transfer surfaces.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the present invention, the adsorption zone is comprises thin sheets of adsorbent paper layers bonded to a substrate. For sorption heat pump processes, the adsorption zone comprises a plurality of such plates disposed on tubes to form a tube and flat plate heat exchanger. The adsorbent layer comprises an adsorbent paper layer. An example of the type of adsorbent paper layer for use in the present invention is disclosed in U.S. Pat. No. 5,650,221 which is hereby incorporated by reference. The adsorbent paper layer of U.S. Pat. No. 5,650,221 is comprised of an improved support material, fibrous material, binders, and high levels of desiccant or adsorbent material. The fibrous materials include cellulosic fibers, synthetic fibers and mixtures thereof Fibrillated fibers, that is, fiber shafts which are split at their ends to form fibrils, i.e., fine fibers or filaments much finer than the fiber shafts are preferred. Examples of fibrillated, synthetic organic fibers useful in the adsorbent paper of the present invention are fibrillated aramid and acrylic fibers. A particularly preferred example of such a fiber is available from E. I. du Pont de Nemours & Company under the designation KEVLAR®. The desiccant or adsorbent may be incorporated therein during fabrication of the paper, or the paper may be formed and the desiccant or adsorbent coated thereon, or a combination of adsorbent incorporation during paper making and coating with adsorbent thereafter may be used. As the thickness of the adsorbent paper increases up to an optimal value, the capacity for heating will be increased. However, since cost also increases with increasing thickness, a balance between heating capacity and cost is necessary. Preferably, the adsorbent paper of the present invention comprises a thickness of from about 0.13 to about 0.75 mm and comprises at least 50 wt-% adsorbent. More preferably, the adsorbent paper comprises from about 0.25 to about 0.6 mm in thickness and comprises more than about 70 wt-% adsorbent. Most preferably, the adsorbent paper is about 0.5 mm in thickness and comprises more than 70 wt-% adsorbent. The adsorbent can be any material capable of adsorbing an adsorbable component such as a refrigerant. The adsorbent may comprise powdered solid, crystalline compounds capable of adsorbing and desorbing the adsorbable compound. Examples of such adsorbents include silica gels, activated aluminas, activated carbon, molecular sieves and mixtures thereof. Molecular sieves include zeolite molecular sieves. Other materials which can be used as adsorbents include halogenated compounds such as halogen salts including chloride, bromide, and fluoride salts as examples. The preferred adsorbents are zeolites. Preferably, at least 70 wt-% of the adsorbent paper is a zeolite molecular sieve.
[0022] The pore size of the zeolitic molecular sieves may be varied by employing different metal cations. For example, sodium zeolite A has an apparent pore size of about 4 Å units, whereas calcium zeolite A has an apparent pore size of about 5 Å units. The term “apparent pore size” as used herein may be defined as the maximum critical dimension of the molecular sieve in question under normal conditions. The apparent pore size will always be larger than the effective pore diameter, which may be defined as the free diameter of the appropriate silicate ring in the zeolite structure. Zeolitic molecular sieves in the calcined form may be represented by the general formula:
Me 2/n O:Al 2 O 3 :xSiO 2 :yH 2 O
[0023] where Me is a cation, x has a value from about 2 to infinity, n is the cation valence and y has a value of from about 2 to 10. The general formula for a molecular sieve composition known commercially as type 13 X is:
1.0±0.2Na 2 O:1.00Al 2 O 3 :2.5±0.5SiO 2
[0024] plus water of hydration. Type 13X has a cubic crystal structure which is characterized by a three-dimensional network with mutually connected intracrystalline voids accessible through pore openings which will admit molecules with critical dimensions up to 10 Å. The void volume is 51 vol-% of the zeolite and most adsorption takes place in the crystalline voids. Typical well-known zeolites which may be used include chabazite, also referred to as Zeolite D, clinoptilolite, erionite, faujasite, also referred to as Zeolite X and Zeolite Y, ferrierite, mordenite, Zeolite A, and Zeolite P. Other zeolites suitable for use according to the present invention are those having high silica content. The adsorbent can be selected from the group consisting of DDZ-70, Y-54, Y-74, Y-84, Y-85, low cerium mixed rare earth exchanged Y-84, calcined rare earth exchanged LZ-210 at a framework SiO 2 /Al 2 O 3 mol equivalent ratio of less than about 7.0 and mixtures thereof.
[0025] The appropriate adsorbent to be selected is dependent upon the planned operating conditions of the heat pump containing the sorption heat pump exchangers of the present invention. Among the factors determining the choice of adsorbent is the source of and amount of power for the heat pump, the desired regeneration temperature and the general climatic conditions that occur where the heat pump will be used. For example, at higher regeneration temperatures, zeolite (X) (from an Si/Al 2 ratio of 2.3 and up) or zeolite (Y) (from an Si/Al 2 ratio of 5 and up) are more effective due to higher heat of adsorption and the resulting greater ability to obtain high loading at relatively high adsorption temperatures. When the regeneration temperature and adsorption temperature are both relatively low, then the preferred adsorbent type is zeolite DDZ-70 (available from UOP LLC, Des Plaines, Ill.) due to its low heat of adsorption and consequently its ability to regenerate at relatively low temperatures.
[0026] For example, when the regeneration temperature and the condensing and adsorption temperatures are below 40° to 50° C., then the DDZ-70 zeolite is a good choice of adsorbent. At higher temperatures such as about 150° C., regeneration temperature and adsorption temperature above 50° C., NaY zeolite works well.
[0027] A heat transfer fluid, such as a cold fluid to cool the adsorption zone to adsorption conditions of adsorption temperature, is introduced at a cold fluid temperature into the heat transfer zone. A hot heat transfer fluid is introduced to the heat transfer zone, when required to raise the temperature of the adsorption zone to desorption conditions such as a desorption temperature. The cold heat transfer fluid and the hot heat transfer fluid may be selected from the group consisting of water, alcohols, ammonia, light hydrocarbons, chloro-fluorocarbons, fluorocarbons, and mixtures thereof. Water is a preferred heat transfer fluid. Similarly, for sorption heat pump operations, a refrigerant is selected from the group consisting of water, alcohols, ammonia, light hydrocarbons, chloro-fluorocarbons, fluorocarbons, and mixtures thereof. It is preferred that the heat transfer fluids and the refrigerants not react with the materials of the heat transfer surface. Additives and inhibitors such as amines can be added to the heat transfer fluids to pacify or inhibit such reactions.
[0028] In the operation of the sorption heat pump system of the present invention, a portion of the adsorbent zones may be in an adsorption mode, an intermediate mode, or a desorption mode. In the typical installation, at least one portion of the adsorbent zones will generally be active in each of the operating modes at any given time in order to provide a continuous process. The desorption mode comprises a desorption temperature ranging from about 80° to about 350° C. and a desorption pressure ranging from about 2 kPa to about 1.5M Pa (220 psia).
[0029] The sorption zone may be operated with a variety of sorbent/refrigerant combinations or pairs. Examples of pairings of such sorbent/refrigerant pairs include zeolite/water, zeolite/ethanol, zeolite/methanol, carbon/ethanol, zeolite/ammonia, zeolite/propane and silica gel/water. The operating conditions will vary with the selection of the sorbent/refrigerant pair.
DETAILED DESCRIPTION OF THE DRAWINGS
[0030] [0030]FIG. 1 shows a single-sided laminate 10 having at least two layers including a substrate layer 12 and an adsorbent-containing layer 14 . The adsorbent layer comprises an adsorbent. Preferably, the adsorbent is selected from the group consisting of zeolite X, zeolite Y, zeolite A, silica gel, silicas, aluminas, and mixtures thereof More preferably, the adsorbent is selected from the group consisting of zeolite Y-54, zeolite Y-74, zeolite Y-84, zeolite Y-85, steam condensed rare earth exchanged Y-54, low cerium rare earth exchanged Y-84, low cerium rare earth exchanged zeolite LZ-210, zeolite DDZ-70 and mixtures thereof. Most preferably, the adsorbent is selected from the group consisting of zeolite Y having a trivalent cation in the β-cage of the zeolite structure. The adsorbent layer may be formed by conventional coating methods such as slip coatings, dipping, spray coating, curtain coating, and combinations thereof. One preferred method of forming an adsorbent layer on the fm plate is by applying a layer of adsorbent paper such as disclosed herein above wherein the paper contains the adsorbent in a uniform layer. The adsorbent paper layer may be laminated to the fin plates by any means such as a heat and moisture resistant adhesive-like epoxy. By applying the adsorbent layer to the fm plate prior to assembly of the sorption heat pump module, the build-up or flooding of adsorbent at the root where the tube contacts the fin plate is avoided. Typically, the adsorbent paper layer has a thickness of between about 0.25 and about 0.6 mm. For layers of this thickness, stacked arrangements of fin plates having from about 300 to about 800 fin plates per meter of tube length may be assembled. The arrangements of fin plates in each of the embodiments of the present invention is optimized for heating power and cost factors. In particular, the fin thickness, fm material, and fin spacing as well as the thickness of the adsorbent layer are optimized to minimize the cost while maximizing the performance of an adsorption heat pump. Fins that are thicker than the optimal thickness will not provide the desired heat transfer. The fms need to be properly spaced for ease of refrigerant flow. One optimal arrangement consisted of 0.31 mm (0.012 inch) thick aluminum fms with 0.51 mm (0.02 inch) thick adsorbent media.
[0031] [0031]FIG. 2 shows a pair of the single-sided laminates of FIG. 1 oriented so that the substrate layers 12 are facing within each pair of single-sided laminates. A heat transfer channel 16 is between each pair of single-sided laminates.
[0032] [0032]FIG. 3 shows an alternate embodiment of the invention wherein two single-sided laminates are corrugated and then mated together to form flow channels for a refrigerant within a subassembly 20 . The subassembly 20 that is formed is sealed at two or three of the four edges. Sealed edges 22 , 24 are shown. In the perspective shown in FIG. 3, a heat transfer fluid would flow in and out of the plane as shown in a heat transfer passage 26 . In the embodiment shown, the uncoated substrate layer 12 is on the interior of the subassembly 20 and the adsorbent-containing layer 14 is on the outside of the subassembly 20 as shown.
[0033] [0033]FIG. 4 shows a view of the subassemblies 20 of FIG. 3 arranged into an assembly 30 . The subassembly 20 has been turned so that the flow path of the heat transfer fluid is now across the side having the adsorbent layer. Arrows show the direction of flow of the heat transfer fluid. An inlet header 32 and an outlet header 34 mate and seal to openings at both ends of subassembly 20 and allow for flow of heat transfer fluid up the headers and across inside surfaces of subassembly 20 . In a heat pump, the entire assembly displayed in FIG. 3 is placed inside a vacuum vessel and spaces 36 between the subassemblies 20 contain the refrigerant that also fills the open portions of the vacuum surrounding the assembly. The primary surface area for heat transfer is the entire inside surface of all the subassemblies 20 .
[0034] [0034]FIG. 5 shows a double-sided laminate 40 that comprises a single sheet 42 of a base material, such as aluminum and layers 44 , 46 of a zeolite matrix bonded to each opposing surface of the base material.
[0035] [0035]FIG. 6 shows a special arrangement of the double-sided laminate of FIG. 5 where there are gaps 48 in the layers 44 , 46 so as to allow for corrugation that will leave uncoated (nonlaminated) sections of the base material exposed. The presence of these gaps allows for bonding of the nonlaminated sections of the laminate to the outside surface of a heat transfer passage.
[0036] [0036]FIG. 7 shows how the gaps 48 are mated to outside surfaces 52 , 54 of heat transfer fluid passages in a unit 56 . A refrigerant 58 is shown flowing next to the laminate. The double-sided laminate of FIG. 6 is shown in a corrugated pattern to maximize surface area.
[0037] [0037]FIG. 8 shows how the repeating units of a heat transfer passage with fin stock bonded to the outside surfaces of the heat transfer passage as in FIG. 7 are stacked to form an entire heat exchanger. An inlet header 62 and an outlet header 64 are shown for flow of the heat exchange fluid to the heat transfer fluid passages of unit 56 . This design combines the advantage of large fm surface with the compact style heat exchanger that has a large primary surface area. In one embodiment of FIG. 8, the metal layers are aluminum plates that have been anodized to prevent any potential corrosion reactions with water. The anodizing step is carried out prior to the lamination and assembly of the heat exchanger core.
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This invention provides a compact heat exchanger that has an effective geometry for heat transfer operations regardless of the heat conductivity of the material chosen for the fin materials. It has further been found that the use of adsorbent coated anodized aluminum for fin materials provides for a very efficient heat exchanger.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] U.S. patent application Ser. No. ______ entitled. “PLASTICIZED, ANTIPLASTICIZED CRYSTALLINE CONDUCTING POLYMERS AND PRECURSORS THEREOF” and U.S. patent application Ser. No. ______ entitled, “METHODS OF FABRICATING PLASTICIZED, ANTIPLASTICIZED AND CRYSTALLINE CONDUCTING POLYMERS AND PRECURSORS THEREOF”, the teachings of which are incorporated herein by reference.
[0002] This application claims priority from Provisional Application Serial No. 60/007,688 filed Nov. 29, 1995
FIELD OF THE INVENTION
[0003] The present invention is directed to polycrystalline electrically conductive polymer precursors and polycrystalline conducting polymers having adjustable morphology and properties.
BACKGROUND
[0004] Electrically conductive organic polymers emerged in the 1970's as a new class of electronic materials. These materials have the potential of combining the electronic and magnetic properties of metals with the light weight, processing advantages, and physical and mechanical properties characteristic of conventional organic polymers. Examples of electrically conducting polymers arc polyparaphenylene vinylenes, polyparaphenylenes, polyanilines, polythiophenes, polyazines, polyfuranes, polythianaphthenes polypyrroles, polyselenophenes, poly-p-phenylene sulfides, polyacetylenes formed from soluble precursors, combinations thereof and blends thereof with other polymers and copolymers of the monomers thereof.
[0005] These polymers are conjugated systems which are made electrically conducting by doping. The doping reaction can involve an oxidation, a reduction, a protonation, an alkylation, etc. The non-doped or non-conducting form of the polymer is referred to herein as the precursor to the electrically conducting polymer. The doped or conducting form of the polymer is referred to herein as the conducting polymer.
[0006] Conducting polymers have potential for a large number of applications in such areas such as electrostatic charge/discharge (ESC/ESD) protection, electromagnetic interference (EMI) shielding, resists, electroplating, corrosion protection of metals, and ultimately metal replacements, i.e. wiring, plastic microcircuits, conducting pastes for various interconnection technologies (solder alternative), etc. Many of the above applications especially those requiring high current capacity have not yet been realized because the conductivity of the processible conducting polymers is not yet adequate for such applications.
[0007] To date, polyacetylene exhibits the highest conductivity of all the conducting polymers. The reason for this is that polyacetylene can be synthesized in a highly crystalline form (crystallinity as high as 90% has been achieved) (as reported in Macromolecules, 25, 4106, 1992). This highly crystalline polyacetylene has a conductivity on the order of 10 5 S/cm. Although this conductivity is comparable to that of copper, polyacetylene is not technologically applicable because it is a non-soluble, non-processible, and environmentally unstable polymer. The polyaniline class of conducting polymers has been shown to be probably the most suited of such materials for commercial applications. Great strides have been made in making the material quite processable. It is environmentally stable and allows chemical flexibility which in turn allows tailoring of its properties. Polyaniline coatings have been developed and commercialized for numerous applications. Devices and batteries have also been constructed with this material. However, the conductivity of this class of polymers is generally on the low end of the metallic regime. The conductivity is on the order of 10 0 S/cm. Some of the other soluble conducting polymers such as the polythiophenes, poly-para-phenylenevinylenes exhibit conductivity on the order of 10 2 S/cm. It is therefore desirable to increase the conductivity of the soluble/processible conducting polymers, in particular the polyaniline materials.
[0008] The conductivity (σ)is dependent on the number of carriers (n) set by the doping level, the charge on the carriers (q) and on the interchain and intrachain mobility (μ)of the carriers.
σ=n q μ
[0009] Generally, n (the number of carriers) in these systems is maximized and thus, the conductivity is dependent on the mobility of the carriers. To achieve higher conductivity, the mobility in these systems needs to be increased. The mobility, in turn, depends on the morphology of the polymer. The intrachain mobility depends on tile degree of conjugation along the chain, presence of defects, and on the chain conformation. The interchain mobility depends on the interchain interactions, the interchain distance, the degree of crystallinity, etc. Increasing the crystallinity results in increased conductivity as examplified by polyacetylene. To date, it has proven quite difficult to attain polyaniline in a highly crystalline state. Some crystallinity has been achieved by stretch orientation or mechanical deformation (A.G. MacDiarmid et al in Synth. Met. 55-57, 753). In these stretch-oriented systems, conductivity enhancements have been observed. The conductivity enhancement was generally that measured parallel to tile stretch direction. Therefore, the conductivity in these systems is anisotropic. It is desirable to achieve a method of controlling and tuning the morphology of polyaniline. It is desirable to achieve a method of controlling and tuning the degree of crystallinity and the degree of amorphous regions in polyaniline, which in turn provides a method of tuning the physical, mechanical, and electrical properties of polyaniline. It is further desirable to achieve highly crystalline and crystalline polyaniline and to achieve this in a simple and useful manner in order to increase the mobility of the carriers and, therefore, the conductivity of the polymer. It is also further desirable to achieve isotropic conductivity, that is conductivity not dependent on direction as with stretch-oriented polyanilines.
OBJECTS
[0010] It is an object of the present invention to provide a polycrystalline material containing crystallites of an electrically conducting polymer precursor and/or electrically conducting polymer having an adjustable morphology.
[0011] It is an object of the present invention to provide a polycrystalline material of an electrically conductive polymer precursor and/or electrically conducting polymer in which the degree of amorphous and crystalline regions is adjustable.
[0012] It is an object of the present invention to provide a polycrystalline material of an electrically conducting polymer precursor and/or electrically conducting polymer having adjustable physical, mechanical, and electrical properties.
[0013] It is an object of the present invention to provide a crystalline electrically conducting polymer precursor and crystalline conducting polymers.
[0014] It is an object of the present invention to provide a highly crystalline electrically conducting polymer precursor and highly crystalline conducting polymers.
[0015] It is an object of the present invention to provide a polycrystalline material of an electrically conducting polymer precursor and/or crystalline conducting polymers to provide a highly crystalline material.
[0016] It is another object of the present invention to provide an electrically conducting polycrystalline material that exhibits enhanced carrier mobility.
[0017] It is another object of the present invention to provide an electrically conducting polycrystalline material which exhibits enhanced conductivity.
[0018] It is another object of the present invention to provide an electrically conducting polycrystalline material which exhibits enhanced isotropic conductivity.
[0019] It is another object of the present invention to provide a plasticization effect in a polycrystalline electrically conducting polymer precursors and/or electrically conducting polymers.
[0020] It is another object of the present invention to provide a polycrystalline material having an antiplasticization effect in electrically conducting polymer precursors and electrically conducting polymers.
[0021] It is another object of the present invention to provide a polycrystalline material of a precursor or electrically conducting polymer containing an additive providing mobility.
[0022] It is another object of the present invention to provide a polycrystalline material of a precursor or electrically conductive polymer containing an additive to induce all enhanced degree of crystallinity.
[0023] It is another object of the present invention to provide a non-stretch oriented polycrystalline film of a precursor or of an electrically conductive polymer which has an enhanced degree of crystallinity.
[0024] It is an object of the present invention to provide a polycrystalline material of an electrically conducting polymer precursor and/or electrically conducting polymer having an increased glass transition temperature.
[0025] It is an object of the present invention to provide an electrically conducting polymer precursor and electrically conducting polymer having an decreased glass transition temperature.
[0026] It is an object of the present invention to provide a polycrystalline material of an electrically conducting polymer precursor and electrically conducting polymer having enhanced mechanical properties.
[0027] It is an object of the present invention to provide a polycrystalline material of an electrically conducting polymer precursor and electrically conducting polymer having decrease mechanical properties.
SUMMARY OF THE INVENTION
[0028] A broad aspect of the present invention is a polycrystalline material comprising crystallites of a precursor to an electrically conductive polymer and/or an electrical conductive polymer. The intersticial regions between the crystallites contain amorphous material.
[0029] In a more particular aspect of the present invention, the amorphous regions of the material contain the additive.
DESCRIPTION OF THE DRAWINGS
[0030] Further objects, features, and advantages of the present invention will become apparent from a consideration of the following detailed description of the invention when read in conjunction with the drawings FIG's. in which:
[0031] [0031]FIG. 1 is a general formula for polyaniline in the non-doped or precursor form.
[0032] [0032]FIG. 2 is a general formula for a doped conducting polyaniline.
[0033] [0033]FIG. 3 is a general formula for the polysemiquinone radical cation form of doped conducting polyaniline.
[0034] [0034]FIG. 4 is a Gel Permeation Chromatograph (GPC) of polyaniline base in NMP (0.1%): GPC shows a trimodal distribution—A very high molecular weight fraction (approx. 12%) and a major peak having lover molecular weight.
[0035] Curve 5 ( a ) is a Wide Angle-X-Ray Scattering (WAXS) spectrum for a polyaniline base film processed from NMP. The polymer film is essentially amorphous. Curve 5 ( b ) is a Wide Angle X-Ray Scattering spectrum for a polyaniline base film that has stretch-oriented (l/lo-3.7). This film was derived from a gel. Curve 5 ( c ) is a Wide Angle-X-Ray Scattering spectrum for a polyaniline-base film containing 10% poly-co-dimethyl propylamine siloxane. This film is highly crystalline.
[0036] [0036]FIG. 6 is a Schematic diagram of a polycrystalline material as taught in present invention having crystalline regions (outlined in (dotted rectangles) with intersticial amorphous regions
[0037] [0037]FIG. 7 is a Dynamic Mechanical Thermal Analysis (DMTA) plot for polyaniline base film cast from NMP. (First Thermal Scan; under Nitrogen).
[0038] [0038]FIG. 8 is a DMTA plot which represents the second thermal scan for a polyaniline base film cast from NMP; This same film was previously scanned as shown in FIG. 7. Film Contains no residual solvent.
[0039] [0039]FIG. 9 is a DMTA plot for polyaniline base film cast from NMP and containing 5% poly-co-dimethyl aminopropyl siloxane (5% N content). First Thermal Scan.
[0040] [0040]FIG. 10 is a DMTA plot for polyaniline base film cast from NMP and containing 5% poly-co-dimethyl aminopropyl siloxane (5% N content). Second Thermal Scan (this same film was previously scanned as shown in FIG. 9) Film Contains no residual solvent.
[0041] [0041]FIG. 11 is a GPC for a polyaniline base solution in NMP containing 5% poly-co-dimethyl aminopropyl siloxane by weight to polyaniline. The polyaniline was 0.1% in NMP.
DETAILED DESCRIPTION
[0042] The present invention is directed toward electrically conducting polymer precursors and conducting polymers having adjustable morphology and in turn adjustable physical, and electrical properties. The present invention is also directed toward controlling and enhancing the 3-dimensional order or crystallinity of conducting polymer precursors and of conducting polymers. In addition, the present invention is directed towards enhancing the electrical conductivity of conducting polymers. This is done by forming an admixture of an electrically conducting polymer precursor or an electrically conducting polymer with an additive whereby the additive provides local mobility to the molecules so as to allow the conducting polymer precursor or conducting polymer chains to associate with one another and achieve a highly crystalline state. An example of such an additive is a plasticizer. A plasticizer is a substance which when added to a polymer, solvates the polymer and increases its flexibility, deformability, generally decreases the glass transition temperature Tg, and generally reduces the tensile modulus. In certain cases, the addition of a plasticizer may induce antiplasticization, that is an increase in the modulus or stiffness of the polymer, an increase in Tg. Herein the additives can provide a plasticization effect, an antiplasticization effect or both effects.
[0043] Examples of polymers which can be used to practice the present invention are of substituted and unsubstituted homopolymers and copolymers of aniline, thiophene, pyrrole, p-phenylene sulfide, azines, selenophenes, furans, thianaphthenes, phenylene vinylene, etc. and the substituted and unsubstituted polymers, polyparaphenylenes, polyparaphenylevevinylenes, polyanilines, polyazines, polythiophenes, poly-p-phenylene sulfides, polyfuranes, polypyrroles, polythianaphthenes, polyselenophenes, polyacctylenes formed from soluble precursors and combinations thereof and copolymers of monomers thereof. The general formula for these polymers can be found in U.S. Pat. No. 5,198,153 to Angelopoulos et al. While the present invention will be described with reference to a preferred embodiment, it is not limited thereto. It will be readily apparent to a person of skill in the art how to extend the teaching herein to other embodiments. One type of polymer which is useful to practice the present invention is a substituted or unsubstituted polyaniline or copolymers of polyaniline having general formula shown in FIG. 1 wherein each R can be H or any organic or inorganic radical; each R can be the same or different; wherein each R 1 can be H or any organic or inorganic radical, each R 1 can be the same or different; x≧1; preferable x≧2 and y has a value from 0 to 1. Examples of organic radicals are alkyl or aryl radicals. Examples of inorganic radicals are Si and Ge. This list is exemplary only and not limiting. The most preferred embodiment is emeraldine base form of the polyaniline wherein y has a value of approximately 0.5. The base form is the non-doped form of the polymer. The non-doped form of polyaniline and the non-doped form of the other conducting polymers is herein referred to as the electrically conducting polymer precursor.
[0044] In FIG. 2, polyaniline is shown doped with a dopant. In this form, the polymer is in the conducting form. If the polyaniline base is exposed to cationic species QA, the nitrogen atoms of the imine (electron rich) part of the polymer becomes substituted with the Q + cation to form an emeraldinie salt as show in FIG. 2. Q + can be selected from H + and organic or inorganic cations, for example, an alkyl group or a metal.
[0045] QA can be a protic acid where Q hydrogen. When a protic acid, HA, is used to dope the polyaniline, the nitrogen atoms of the imine part of the polyaniline are protonated. The emeraldine base form is greatly stalbilized by resonance effects. The charges distribute through the nitrogen atoms and aromatic rings making the imine and amine nitrogens indistinguishable. The actual structure of the doped form is a delocalized polysemiquinone radical cation as shown in FIG. 3.
[0046] The emeraldine base form of polyaniline is soluble in various organic solvents and in various aqueous acid solutions. Examples or organic solvents are dimethylsulfoxide (DMSO), dimethylformamide (DMF) and N-methylpyrrolidinone (NMP), dimethylene propylene urea, tetramethyl urea, etc. This list is exemplary only and not limiting. Examples of aqueous acid solutions is 80% acetic acid and 60-88% formic acid. This list is exemplary only and not limiting.
[0047] Polyaniline base is generally processed by dissolving the polymer in NMP. These solutions exhibit a bimodal or trimodal distribution in Gel Permeation Chromatography (GPC) as a result of aggregation induced by internal hydrogen bonding between chains as previously described in U.S. patent application Ser. No. 08/370,128, filed on Jan. 9, 1995, the teaching of which is incorporated herein by reference. The GPC curve for typical polyaniline base in NMP is shown in FIG. 4.
[0048] Polymers in general can be amorphous, crystalline, or partly crystalline. In the latter case, the polymer consists of crystalline phases and amorphous phases. The morphology of a polymer is very important in determining the polymer's physical, mechanical, and electronic properties.
[0049] Polyaniline base films processed from NMP either by spin coating or by solution casting techniques are amorphous as can be seen in FIG. 5 a which depicts the Wide Angle X-Ray Scattering (WAXS) spectrum for this material. Amorphous diffuse scattering is observed. Some crystallinity is induced in these films by post processing mechanical deformation especially if these films are derived from gels as described by A.G. MacDiarmid et al in Synth. Met. 55-57, 753 (1993), WAXS of a stretch oriented film having been stretched (l/lo=3.7X) derived from a gel is shown in FIG. 5 b . Some has been induced as compared to the non-stretch oriented films as evidenced by the defined scattering peaks.
[0050] Doping the amorphous polyaniline base films (those having structure shown in FIG. 5 a ) with aqueous hydrochloric acid results in isotropic conductivity of 1 S/cm. Such films are not crystalline. Similar doping of stretch oriented films results in anisotropic conductivity where conductivity on the order of 10 2 S/cm is measured parallel to the stretch direction whereas conductivity on the order of 10 0 S/cm is measured perpendicular to the stretch direction. It should also be noted that some level of crystallinity is lost during the doping process in these films.
[0051] According to the present invention, the interchain (polymer chain) registration is increased as compared to a stretch oriented film.
[0052] [0052]FIGS. 7 and 8 show the dynamic mechanical thermal analysis (DMTA) spectrum for a polyaniline base film processed from NMP alone. FIG. 7 is the first scan where a Tg of approx. 118 is observed as a result of the residual NMP which is present in the film. FIG. 8 is the second thermal scan of the same film. This film has no residual solvent and a Tg of ≅251° C. is measured for the polyaniline base polymer.
[0053] When an additive such as a plasticizer, such as a poly-co-dimethyl propylamine siloxane, is added to the polyaniline base completely different properties and morphology is observed. The siloxane has a polar amine group which facilitates the miscibility of the polyaniline base and the plasticizer. The DMTA of a polyaniline base film cast from NMP and containing 5 5 by weight to polyaniline of the poly-co-dimethyl propyl amine siloxane exhibits a lower Tg on the first thermal scan as compared to polyaniline base processed from NMP alone (FIG. 9) as a result of plasticization induced by the siloxane. However, on the second thermal scan of this film (FIG. 10), the polymer exhibits an increase in Tg as compared to polyaniline processed from NMP. When the polysiloxane is added to a solution of polyaniline base, the siloxane due to the polar amine group can interact with the polymer chains and disrupt some of the polyaniline interactions with itself or some of the aggregation. Thus, the polysiloxane first induces some deaggregation. However, the polysiloxane has multiple amine sites and thus, it can itself hydrogen bond with multiple polyaniline base chains and thus, the polysiloxane facilitates the formation of a cross-linked network. This cross-linked network accounts for the increased Tg observed in the DMTA. Tg is characteristic of the amorphous regions of a polymer and in this case the amorphous regions consist of a cross-linked polyaniline/polysiloxane network. Thus, the polysiloxane is inducing an antiplasticization effect in polyaniline base as the Tg is increased. Generally, plasticizers reduce Tg. GPC data (FIG. 11) is consistent with this model. The addition of the poly-amino containing siloxane to a polyaniline base solution in NMP results in a significant increase in the high molecular weight fractions depicting the cross-linked network which forms between polyanilie and the plasticizer.
[0054] In addition to the cross-linked network the siloxane induces in the amorphous regions, concomittantly it also is found to induce significant levels of crystallinity in polyaniline base as a result of the local mobility that it provides. FIG. 5 c shows the WAXS for a polyaniline base film processed from NMP containing 10% of the poly amino containing siloxane. As can be seen highly crystalline polyaniline has bee attained. Much higher levels of crystallinity as compared to FIG. 5 b for the stretch oriented films.
[0055] Thus polyaniline by the addition of the siloxane forms a structure depicted in FIG. 6 where crystalline regions of highly associated polyaniline chains (outlined by a rectangle) are formed with intersticial amorphous regions. In most cases, the additive resides in the amorphous intersticial sites. The degree of crystallinity (number of crystalline sites) and the size of the crystalline domains as well as the degree of amorphous regions and the nature of the amorphous region (aggregated, i.e. cross-linked or not) can be tuned by the type and amount of additive. In turn, by controlling the above, the properties of the material can also be controlled.
[0056] With the poly-co-dimethyl aminopropyl siloxane (5% N content), loadings ranging from 0.001 to 20% by weight gives highly crystalline polyaniline. The highly crystalline polyaniline in turn exhibits increased modulus, stiffness, yield and tensile strengths, hardness, density and softening points. Thus, the siloxane at these loadings is having an antiplasticization effect. Above 20% loading, the crystallinity begins to decrease. As the crystallinity decreases, the modulus, stiffness, Yield and tensile strengths, hardness, density and softening points begin to decrease. Thus, the siloxane at these loadings begins to have a plasticization effect. The siloxane content becomes high enough that it disrupts the polyaniline base interactions in the crystalline regions. With the poly co dimethyl aminopropyl siloxanes having 0.5 and 13% N ratios, similar trends are observed but the particular amount of siloxane needed to have a plasticization effect or an antiplasticization effect varies. Thus, the degree of crystallinity and the degree of amorphous regions and in turn the properties of polyaniline can be tuned by the nature of the additive as well as the amount of additive. Indeed, using the same additive but simply changing the loading dramatically changes the morphology and in turn the properties of polyaniline. electronic properties of the polymer are also impacted. The conductivity of a polyaniline base film cast from NMP and containing 1% by weight poly-co-dimethyl aminopropyl siloxane which is doped by aqueous hydrochloric acid is 50 S/cm as compared to 1 S/cm for a polyaniline film with no plasticizer. This is isotropic conductivity. The doped film containing the polysiloxane retains the highly crystalline structure.
[0057] The degree of crystallinity and the degree of amorphous regions and in turn the physical, mechanical, and electronic properties can be tuned by the particular additive used and by the amount of additive. For example, the Tg of polyaniline can be increased or decreased by the amount and type of additive. The mechanical properties such as tensile properties, modulus, impact resistance, etc. can be tuned as described above. The additive can range from 0.001 to 90% by weight, more preferably from 0.001 to 50% and most preferably from 0.001 to 25%. A list of plasticizers that can be used to practice the present invention is given in Table 1. The additive can also be removed from the final film structure if so desired by appropriate extraction.
SPECIFIC EXAMPLES
[0058] Polyaniline Synthesis Polyaniline is synthesized by the oxidative polymerization of aniline using ammonium peroxydisulfate in aqueous hydrochloric acid. The polyaniline hydrochloride precipitates from solution. The polymer is then neutralized using aquoeous ammonium hydroxide. The neutralized or non-dope polyaniline base is then filtered, washed and dried. Polyaniline can also be made by electrochemical oxidative polymerization as taught by W. Huang, B. Humphrey, and A. G. MacDiarmid, J. Chem. Soc., Faraday Trans. 1, 82, 2385, 1986.
[0059] Polyaniline Base in NMP: The polyaniline base powder is readily dissolved in NMP up to 5% solids. Thin films (on the order of a micron) can be formed by spin-coating. Thick films are made by solution casting and drying (70° C. in vacuum oven under a nitrogen purge for 15 hours). These solutions and films have the properties described above.
[0060] Polyaniline Base in NMP/Plasticizer
[0061] a. Polyaniline Base was first dissolved in NMP to 5% solids and allowed to mix well. A poly-co-dimethyl, aminopropyl siloxane (N content 5% relative to repeat unit) was dissolved to 5% in NMP. The siloxane solution was added to the polyaniline base solution. The resulting admixture was allowed to mix for 12 hours at room temperature. A number of solutions were made having from 0.001% to 50% siloxane content (by weight relative to polyaniline). Thin films were spin-coated onto quartz substrates; Thick films were prepared by solution casting and baking the solutions at 70° C. in a vacuum oven under a Nitrogen purge for 15 hours). The solutions and the films have the properties described above.
[0062] b. The same experiment described in (a) was carried out except that the plasticizer was a poly-co-dimethyl, aminopropyl siloxane in which the N content was 13%.
[0063] c. The same experiment described in (a) was carried out except that the plasticizer was a poly-co-dimethyl, aminopropyl siloxane in which the N content was 0.5%.
[0064] d. The same experiment described in (a) was carried out except that the plasticizer was polyglycol diacid.
[0065] e. The same experiment described in (a) was carried out except that the plasticizer was 3,6,9-trioxaundecanedioic acid.
[0066] f. The same experiment described in (a) was carried out except that the plasticizer was poly(ethylene glycol) tetrahydro furfuryl ether.
[0067] g. The same experiment described in (a) was carried out except that the plasticizer was glycerol triacetate.
[0068] h. The same experiment described on (a) was carried out except the plasticizer was epoxidized soy bean oil.
[0069] Polyaniline Base in NMP/m-Cresol/Plasticizer
[0070] The same experiment as described in (a) was carried out except that polyaniline base and the plasticizer was dissolved in NMP/m-Cresol mixtures in which m-Cresol ranged from 1 to 99%
[0071] Polyaniline Base in m-Cresol/Plasticizer
[0072] The same experiment as described in (a) was carried out except that the polyaniline base was dissolved in m-Cresol and the plasticizer was dissolved in m-Cresol.
[0073] Polyaniline Base in m-Cresol and in NMP/m-Cresol
[0074] Polyaniline Base was dissolved in m-Cresol and in NMP/m-Cresol combinations to 5% solids. The m-Cresol in the latter system being the additive ranged from 1 to 99%. Free-Standing films were made by solution casting techniques. With increasing m-cresol content, the polyaniline exhibited a WAXS similar to that shown in FIG. 5 a except that the amorphous scattering peak became somewhat sharper indicative of some crystallinity. However, this was significantly less than observed with the siloxane plasticizer.
[0075] Doped Polyanilines
[0076] a 1. Hydrochloric Acid and/or Methanesulfonic Acid Doped Films
[0077] Polyaniline base films made as described above were doped by aqueous acid solutions of hydrochloric or methanesulfonic acid. The films were immersed in the acid solution for 12 hours for thin films and 36 hours for the thick films. The conductivity of a polyaniline base film processed from NMP and doped with these acid solutions is 1 S/cm The conductivity of a base film processed from NMP and 1% poly-co-dimethyl, amiopropyl siloxane (5%N content) was 50 S/cm.
[0078] [0078] 2 . Sulfonic Acid Doped Polyanilines
[0079] Polyaniline Base was dissolved in a solvent such as NMP or NMP/m-Cresol combinations, etc. from 1 to 5% solids. To this solution was added a dopant such camphorsulfonic acid or acrylamidopropanesulfonic acid (previously reported in U.S. patent application Ser. No. 595,853 filed on Feb. 2, 1996). These solutions were used to spin-coat or solution cast films. In some experiments, the plasticizer such as the poly-co-dimethyl, aminopropyl siloxane in a solvent was added to the doped polyaniline solution. In certain other experiments, the plasticizer was first added to the pani base solution. The dopant was then added to the polyaniline solution containing the plasticizer.
[0080] The teaching of the following U.S. Patent Applications are incorporated herein by reference:
[0081] “CROSS-LINKED ELECTRICALLY CONDUCTIVE POLYMERS, PRECURSORS THEREOF AND APPLICATIONS THEREOF”, application Ser. No. 595,853, filed Feb. 2, 1996;
[0082] “METHODS OF FABRICATION OF CROSS-LINKED ELECTRICALLY CONDUCTIVE POLYMERS AND PRECURSORS THEREOF”, application Ser. No. 594,680, filed Feb. 2, 1996;
[0083] “DEAGGREGATED ELECTRICALLY CONDUCTIVE POLYMERS AND PRECURSORS THEREOF”, application Ser. No. 370,127, filed Jan. 9, 1995; and
[0084] “METHODS OF FABRICATION OF DEAGGREGATED ELECTRICALLY CONDUCTIVE POLYMERS AND PRECURSORS THEREOF”, application Ser. No. 370,128, filed Jan. 9, 1995.
[0085] While the present invention has been shown and described with respect to a preferred embodiment, it will be understood that numerous changes, modifications, and improvements will occur to those skilled in the art without departing from the spirit and scope of the invention.
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Polycrystalline materials containing crystallies of precursors to electrically conductive polymers and electrically conductive polymers are described which have an adjustable high degree of crystallinity. The intersticial regions between the crystallites contains amorphous material containing precursors to electrically conductive polymers and/or electrically conductive polymers. The degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. This is preferable achieved by including additives, such as plasticizers and diluents, to the solution from which the polycrystalline material is formed. The morphology of the polycrystalline material is adjuistable to modify the properties of the material such as the degree of crystallinity, crystal grain size, glass transition temperature, thermal coefficient of expansion and degree of electrical conductivity. High levels of electrical conductivity are achieved in in the electrically conductive polycrystalline materials without stretch orienting the material. The enhanced electrical conductivity is isotropic as compared to a stretch oriented film which has isotropic electrical conductivity.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a fuel enrichment apparatus for a fuel mixer or carburetor. More specifically the invention is directed to a gaseous type carburetor utilizing a gaseous fuel combustible in an internal combustion engine. The added distinction of this invention is that it can be applied to either an air valve carburetor or to a carburetor with a fixed venturi. The invention is, therefore, applicable to a dual fuel type carburetor, that is, a carburetor or carburetor tandem that will operate with either liquid or gaseous fuel although the enrichment arrangement functions only during the gaseous operation.
The enrichment aspect of the invention is engageable at the start-up or cranking of an internal combustion engine to aid in starting, and is also available to induce supplemental fuel at wide open throttle or heavy load.
Prior art carburetors had various devices for idle control and for supplemental fuel at wide open throttle. Many supplemental fuel devices are known for liquid fuel carburetors in conjunction with a fixed venturi in the induction passage. Still other devices have shown idle assist devices for liquid petroleum (LP), gas fuel mixers and have included devices utilizing high pressure lines from the primary side of an LP gas evaporator rather than utilizing the low pressure fuel of the secondary side of the LP gas evaporator.
The present structure can be utilized in a fixed venturi type carburetor, but it can also be applied to an air valve type carburetor wherein it is generally considered that this type carburetor has a variable venturi such that the flow rate may be variable but the pressure head is constant in the induction passage above the throttle plate. The invention monitors the low pressure gas of the main fuel supply line. At start-up of an internal combustion engine there is little or no manifold vacuum and, therefore, insufficient low pressure in the induction passage to open the air valve in an air valve carburetor and induct fuel through the induction passage. There is, however a slight pressure depression below atmospheric pressure just above the throttle plate. This pressure depression is about six (6) inches of water column (6" w.c.). At the cranking of an engine additional fuel near the throttle plate is required for starting, and at full throttle added fuel is required to satisfy the added load. At idle or at cruising speed the pressure drop in the induction passage is adequate to actuate opening of an air valve and is sufficient to induce gas past a fuel metering cone into the engine for combustion; therefore, fuel enrichment is not required at idle or cruising speeds. Should the engine revolutions per minute (RPM) decline at wide open throttle due to an overload condition, there would be a change in the manifold vacuum below that necessary to open the air valve to allow adequate fuel for the engine. The fuel enrichment apparatus would respond to such a condition so as to supplement the main fuel supply under the changed vacuum condition.
SUMMARY OF THE INVENTION
The present invention relates to a fuel enrichment apparatus for a gaseous fuel carburetor. The invention supplies supplemental fuel at the start-up or wide open throttle conditions, low vacuum or heavy load, for such carburetor when applied to an internal combustion engine. The invention is particularly applicable to an air valve type carburetor wherein the main fuel supply is dependent upon the manifold vacuum to induce or pull fuel and air through the induction and mixing passage. The invention circumvents the main fuel supply for initial starting, without continuous fuel flow through the invention during idle and cruising ranges. In addition, at wide open throttle or heavy load the fuel enrichment structure of the invention again supplies fuel to the induction passage. Further, this supplemental fuel supplied by the invention does not require an added fuel line but rather it extracts the fuel from the main fuel line, generally from the secondary side of an evaporator at a low pressure. This last feature obviates any necessity of utilizing a high pressure fuel line, where such high pressure fuel is derived from either the primary section of a fuel evaporator or through the use of an added fuel pump.
In a preferred embodiment the invention includes an atmospheric vent with two diaphragm valves in parallel. The supplemental fuel bypasses the main fuel metering cone and is transferred to the induction passage upstream of the throttle plate. The supplemental fuel valve is opened at start-up by a diaphragm valve acting in response to a small pressure drop near the throttle plate, as atmospheric pressure flexes the diaphragm of an expansion chamber motor to open the fuel valve. After engine start-up there is an increase in manifold vacuum below the throttle plate and the second diaphragm valve opens to allow atmospheric air to enter the supplemental fuel passage. This balances the pressure to atmospheric on both sides of the first or supplemental fuel line diaphragm, allowing this valve to close at what is referred to as engine idle speed. At wide open throttle the manifold vacuum is the same as the pressure in the induction passage, which pressure actuates the supplemental fuel line diaphragm, and this depression from atmospheric pressure again opens the supplemental fuel line, allowing supplemental fuel to enter the induction passage.
BRIEF DESCRIPTION OF THE DRAWINGS
In the several figures of the drawings, like reference numerals identify like components, and in those drawings:
FIG. 1 is a diagrammatic sectional side view of the fuel enrichment apparatus of the present invention attached to an air valve gaseous fuel carburetor induction passage, shown in the start-up or cranking position;
FIG. 2 is a diagrammatic sectional view of the carburetor fuel enrichment apparatus of FIG. 1 on an enlarged scale;
FIG. 3 is a diagrammatic sectional view of the carburetor fuel enrichment apparatus arrangement with the engine at idle or cruise speed; and
FIG. 4 illustrates a diagrammatic sectional view of the apparatus with wide open throttle.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 an air valve gaseous fuel carburetor 10 has six main components. The first main component is a central body portion 12 defining an air induction and mixing passage 14 with side walls 16 and 18, an entry end 20, and a discharge end 22. Side wall 18 of air induction and mixing passage 14 defines an auxiliary fuel port 24 and side wall 16 defines a monitoring port 26. The second major component is a main fuel supply passage 28 with a sidewall 29, a deflector 30 permanently affixed in fuel supply passage 28 and a fuel port 31 defined by sidewall 29. The third major component is a spring-biased, normally-closed diaphragm valve 32 mounted atop induction passage 14 with the fourth component, a fuel metering cone 34, mounted below the diaphragm valve 32 in the induction passage 14 and terminating in the end of main fuel supply passage 28. This diaphram valve 32 is responsive to the pressure depression in the induction passage 14 which depression is monitored through port 26 and a passage 36 communicating with diaphragm valve 32. Mounted in the induction passage 14 is a movable throttle member 38, the fifth major component, pivotally mounted to rotate about a shaft 40 which is centrally located. The throttle plate 38 is responsive to an external signal or force through any communication or linkage means (not shown) known in the art. As this throttle 38 is opened it reflects a general increase in the fuel demand by the engine (not shown) to which the carburetor of this preferred embodiment is attached.
Attached by any conventional means (not shown) to the carburetor 10 is a subassembly fuel enrichment apparatus 42, the sixth major component, illustrated in FIG. 1 and in an enlarged view in FIG. 2. This subassembly includes an auxiliary fuel valve assembly 44, with an auxiliary fuel valve body 45, an aperture 46 and an auxiliary fuel inlet passage 47 both defined by valve body 45, a biasing means 48 acting only to maintain valve 44 to a normally closed position over aperture 46. Said bias means 48 generally has a force responsive to an induction line pressure drop at cranking of about 2 to 5 inches of water column, nominally 4 inches of water column. An expansion chamber motor 50 with a chamber 52 communicates with aperture 46 and thereby communicates with induction passage 14 through a connecting passage 54 between aperture 46 and auxiliary fuel exit port 24. An aperture 46 communicates with main fuel supply passage 28 through auxiliary fuel inlet passage 47 when valve 44 is open. A second chamber 56 of expansion chamber motor 50 is vented to the atmosphere through a port 58 defined by valve body 45 and a passage 60 connecting to an atmospheric vent line 62 wherein is located a restriction 64. The expansion chamber motor 50 has a flexible diaphragm 66 secured between chambers 52 and 56 and with a valve operator 68 connected to said diaphragm 66 to engage normally closed valve 44 in response to a slight pressure depression in chamber 52 of expansion motor 50. Such a depression would therefore allow fuel to flow from main fuel supply line 28 past valve 44 to auxiliary fuel port 24 in response to a slight pressure drop below atmospheric in induction passage 14 as is experienced in a gaseous fuel carburetor at start-up or cranking but before an adquate vacuum is available in induction passage 14 to open diaphragm valve 32 and fuel metering cone 34 to induct fuel to the combustion chamber. This diaphragm valve 32 and fuel metering cone 34 arrangement has therefore been successfully bypassed and ease of start up has been accomplished.
A second normally closed control valve assembly 70 of subassembly 42 with a body 71 is provided with a first chamber 72 and a second chamber 74 with a flexible diaphragm 76 and normally closed control valve 77 biased by bias means 78 to close a port 80 defined by the valve body 71. Means 78 is of such a strength as to generally maintain the valve 77 in closed position against a vacuum up to about 6 inches of mercury, although this bias means force could be set to any desired level. First chamber 72 of control valve assembly 70 is communicated with atmospheric vent line 62 through a passage 82. Second chamber 74 is in communication with the volume below throttle plate 38 by passage 84. Port 80 is in communication with exit fuel port 24 through a passage 54. When the internal combustion engine connected with the carburetor 10 is shut down, control valve 77 is normally biased to close port 80 by bias means 78. The control valve 77 is closed at start up or wide open throttle as the manifold pressure depression below throttle plate 38 is inadequate to reduce the pressure in chamber 74 to allow atmospheric pressure communicated to chamber 72 to overcome biasing means 78. At idle speed and at a cruising or engine speed less than wide open throttle, as shown in FIG. 3, the manifold pressure depression communicated to chamber 74 below the throttle plate 38 is adequate to open control valve 77 and allows equivalent pressure to communicate to fuel exit port 24 and aperture 46 thereby balancing the pressure on both sides of flexible diaphragm 66 of expansion chamber motor 50 and closing valve 44 in response to bias means 48. In addition, air valve 32 is open or retracted in response to the reduced atmospheric pressure above throttle plate 38 communicated by passage 36, and therefore, fuel metering cone 34 is withdrawn from fuel line 28 to allow fuel to be inducted to induction passage 14.
At wide open throttle as illustrated in FIG. 4 control valve 77 is again closed and auxiliary fuel valve 44 is again open to allow fuel to bypass fuel metering cone 34 and be introduced through passage 47, aperture 46, passage 54 and fuel exit port 24. Valve 44 is opened by valve operator 68 of expansion chamber motor 50 moving to the left in this illustration under the slightly reduced pressure of the induction passage 14 above throttle 38, but this slight pressure is the same or about the same as the pressure being monitored by passage 84 to chamber 74 of valve 77 which reduced pressure is inadequate to overcome the spring biasing force of bias means 78. Valve 77 is again closed under these circumstances, and atmospheric pressure is present in chamber 50, and reduced pressure from atmospheric is in chamber 52 to again open valve 44.
The subassembly 42 is shown as an integral part of the illustrated carburetor 10 but it is not necessary to the operation as it could be an independent assembly connected at the ports shown in the drawing. There is no separate or pressurized fuel supply source required for the invention except the low pressure main fuel supply line 28 which is connected to the subassembly 42 by a passage to said main fuel passage 28. Supplemental fuel is not continuously supplied to the carburetor induction passage 14 except at start-up or cranking and at wide open throttle. The action of the fuel enrichment apparatus is based upon engine demand not on an external signal. That is, the fuel is supplied only when needed in response to the engine manifold vacuum measured at approximately the line of the throttle plate 38. It can be readily seen by one skilled in the art that the fuel enrichment apparatus could be utilized with a fixed venturi gaseous carburetor although its distinctive characteristics are more applicable to the operation of an air valve type carburetor. This fuel enrichment device was illustrated as mounted to the side of a op mounted air valve diaphragm carburetor but it is as applicable to a gaseous fuel mixer of the type illustrated in U.S. Pat. No. 4,063,905.
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A fuel enrichment apparatus and method is shown for a gaseous fuel carburetor of either a fixed venturi or air valve type. The apparatus provides fuel enriching at the starting and wide open throttle conditions of the carburetor when the pressure drop in the induction passage is at a minimum. The apparatus also economizes on fuel usage by being closed to fuel transfer at idle speed and normal engine speed. The apparatus operates from the fuel supply line to the carburetor with only the fuel pressure available in that line, thereby obviating the need for either a second fuel line or a high pressure fuel line.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a novel ink composition and, more particularly, to an ink composition for digital textile printing, which is suitable for ink-jet printing on cellulose fiber materials.
[0003] 2. Description of Related Art
[0004] Ink-jet printing is one kind of non-impact printing technology, and the required technical feature of the ink-jet printing is to provide images with sharpness and clearness. In order to obtain images with excellent printing quality, the ink used in ink-jet printing must show high light fastness, optical density, solubility, storage stability, and smoothness and ease of printing.
[0005] The ink-jet printing is applied in textile industry for many years. This method can be performed without use of a printing screen, so it is possible to save a lot of time and cost. Therefore, the ink-jet printing is suitable for production conditions of variation, small quantity, and customization, particularly.
[0006] From the application point of view, the ink for the ink-jet printing must have some unique properties that are different from general inks. The ink composition for the ink-jet printing should not only meet the requirements for viscosity, stability, surface tension, and fluidity, but also meet the requirements for color strength, fixation, fiber-dye bonding stability, and wet fastness.
[0007] The ink composition for the ink-jet printing comprises water-soluble dye or water-dispersible pigment; wherein the dye or the pigment can be soluble or disperse in water, or in a liquid medium containing water-soluble organic solvent. In addition, the ink composition can further comprise a surfactant, which can modify the properties of the ink, to meet the requirement for the textile ink-jet printing.
[0008] U.S. Pat. No. 6,780,229 has disclosed an ink composition, which comprises an organic buffer to maintain the pH value of the ink composition between 4 to 8. U.S. Pat. No. 6,015,454 has disclosed another ink composition, which comprises at least one reactive dye, and 1,2-propylene glycol or N-methyl-2-pyrrolidone, to improve the color strength and fixation. However, this ink composition has a problem in storage stability, durable printing stability, and nozzle clogging. US 2003/0172840 has disclosed another ink composition, which comprises at least one dye, sulfolane, and a buffer system, to prevent the problems of storage stability and nozzle clogging. Unfortunately, the chlorine-resistance fastness, high color strength, and dye solubility of this ink composition are not good enough.
[0009] Hence, it is desirable to provide an ink composition for digital textile printing, which exhibits high pH stability, low color deterioration, high color strength, and high dye concentration.
SUMMARY OF THE INVENTION
[0010] The object of the present invention is to provide a novel ink composition, which exhibits high pH stability, good storage stability, smoothness and ease in printing, and reduction in color deterioration.
[0011] The present invention provides an ink composition for digital textile printing, which comprises:
[0012] (A) a reactive dye, which is presented in an amount of 95˜99.9% by weight; and
[0013] (B) an organic buffer, which is presented in an amount of 0. 15˜5% by weight.
[0014] Specific examples of the aforementioned component (A) are represented as following formulas (I-1) to (I-16):
[0000]
[0015] Furthermore, according to the ink composition for digital textile printing of the present invention, the component (A) may be a single dye, or a mixture of multiple reactive dyes.
[0016] Specific examples of the aforementioned component (B) are represented as following formulas (II-1) to (II-2):
[0000]
[0017] According to the ink composition for digital textile printing of the present invention, the compounds of formulas (I-1) to (I-16) and formulas (II-1) to (II-2) are represented in the form of free acid. However, in practice, these compounds may be metallic salts or ammonium salts thereof. More likely, these compounds may be alkaline metallic salts or ammonium salts thereof.
[0018] Besides, according to the ink composition for digital textile printing of the present invention, the ink composition not only comprises the component (A) and the component (B), but further comprises: (C) an organic solvent, and (D) water. The organic solvent of the component (C) is selected form the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, glycerine, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and triethanolamine. Moreover, the content of the component (A) is 0.095˜33.25% by weight; the content of the component (B) is 0.005˜1.75% by weight; the content of the component (C) is 5˜35% by weight; and the content of the component (D) is 30˜94.9% by weight.
[0019] Furthermore, the ink composition for digital textile printing of the present invention can further comprise: (E) nonionic surfactant, which is presented in an amount of 0.1˜5% by weight. The component (E) can be alkynediol based surfactant, or alkoxy surfactant. Specific examples of the alkynediol based surfactant includes: Surfynol 485, Surfynol 465, Surfynol 440, Surfynol 420, Surfynol 104 (commercially available from Air Products & Chemicals, Inc.), and specific examples of the alkoxy surfactant includes: Tergitol 15-S-5, Tergitol 15-S-7, Tergitol 15-S-9 (commercially available from Union Carbide).
[0020] Moreover, the ink composition for digital textile printing of the present invention may further comprises (F) microbicide, if necessary. The content of the component (F) is 0.01˜1% by weight based on the total weight of the ink composition. Specific examples of the microbicide (F) includes: NUOSEPT (commercially available from Nudex Inc., a division of Huls Americal), UCARCIDE (commercially available from Union Carbide), VANCIDE (commercially available from RT Vanderbilt Co.), and PROXEL (commercially available from ICI Americas). The aforementioned additives are disclosed in TW 589352 or U.S. Pat. No. 5,725,641.
[0021] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The reactive dye compounds used in the present invention are commercially available from Everlight Chemical Industrial Corp. The organic buffer compounds used in the present invention are commercially available from HOPAX chemical co. LTD.
[0023] In the ink composition for digital textile printing of the present invention, the reactive dye or the organic buffer can be used alone, or combined with the aforementioned compounds or alkaline metallic salts thereof. Preferably, the salt content of these compounds should be low, i.e. total salt content in the ink composition is lower than 0.05% by weight, based on the total weight of the ink composition. Desalination can be performed on the ink composition with relative high salt content, wherein the salts are generated during production, and/or generated from diluents. The method of thin-film separation can be used for desalination, such as centrifugal filtration, nanofiltration, reverse osmosis, or dialysis.
[0024] The ink composition for digital textile of the present invention can be prepared by known methods. For example, each components with predetermined amounts is mixed in water to prepare the ink composition of the present invention.
[0025] The following examples are intended for the purpose of illustration of the present invention. However, the scope of the present invention should be defined as the claims appended hereto, and the following examples should not be construed as in any way limiting the scope of the present invention. In the present invention, the compounds are presented in form of free acid. Nevertheless, the actual form of these compounds may be metallic salts or ammonium salts thereof, and more likely, may be alkaline metallic salts or ammonium salts thereof. Without specific explanations, the unit of the parts and percentages used in the examples is calculated by weight, and the temperature is represented by Celsius degrees (° C.). The relation between the parts by weight and the parts by volume is just like the relation between kilogram and liter.
EXAMPLE 1
Preparation of a Dye Composition
[0026] 50 parts of the compound of the formula (I-1), and 50 parts of the compound of the formula (I-2) were mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of the compound of the formula (II-1) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition of the present example.
EXAMPLE 2
Preparation of a Dye Composition
[0027] 100 parts of the compound of the formula (I-3) was mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 5 parts of the compound of the formula (II-1) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition of the present example.
EXAMPLE 3
Preparation of a Dye Composition
[0028] 100 parts of the compound of the formula (I-4) was mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 0.1 parts of the compound of the formula (II-1) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition of the present example.
EXAMPLE 4
[0029] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-5).
EXAMPLE 5
[0030] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-6).
EXAMPLE 6
[0031] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-7).
EXAMPLE 7
[0032] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-8).
EXAMPLE 8
[0033] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-9).
EXAMPLE 9
Preparation of a Dye Composition
[0034] 83.4 parts of the compound of the formula (I-10), 11.1 parts of the compound of the formula (I-12), and 5.5 parts of the compound of the formula (I-11) were mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 4-6. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of the compound of the formula (II-2) was added into the resulted solution, followed by mixing and adjusting the pH value to 5.0-5.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition of the present example.
EXAMPLE 10
Preparation of a Dye Composition
[0035] 20 parts of the compound of the formula (I-13), and 80 parts of the compound of the formula (I-14) were mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of the compound of the formula (II-1) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition of the present example.
EXAMPLE 11
[0036] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-15).
Example 12
[0037] The method for preparing the dye composition of the present example was the same with the method illustrated in Example 2, except that the compound of the formula (I-3) was substituted with the compound of the formula (I-16).
EXAMPLE 13
Preparation of an Ink Composition
[0038] 15 parts of the dye composition prepared in Example 1, 10 parts of N-methyl-2-pyrrolidone (component (C)), 10 parts of 2-pyrrolidone (component (C)), 0.5 parts of surfactant Surfynol 465 (component (E)), 0.2 parts of microbicide Proxel XL2 (component (F)), and water (component (D)), in the sum of 100 parts, are mixed by a mixing machine for 30 min. Then, absolute filtration was performed on the mixture with 0.45 μm filter paper to obtain an ink composition of the present example.
EXAMPLE 14
Preparation of an Ink Composition
[0039] 0.1 parts of the dye composition prepared in Example 3, 5 parts of 2-pyrrolidone (component (C)), 0.5 parts of surfactant Surfynol 465 (component (E)), 0.2 parts of microbicide Proxel XL2 (component (F)), and water (component (D)), in the sum of 100 parts, are mixed by a mixing machine for 30 min. Then, absolute filtration was performed on the mixture with 0.45 μm filter paper to obtain an ink composition of the present example.
EXAMPLE 15
Preparation of an Ink Composition
[0040] 35 parts of the dye composition prepared in Example 4, 35 parts of N-methyl-2-pyrrolidone (component (C)), 0.5 parts of surfactant Surfynol 465 (component (E)), 0.2 parts of microbicide Proxel XL2 (component (F)), and water (component (D)), in the sum of 100 parts, are mixed by a mixing machine for 30 min. Then, absolute filtration was performed on the mixture with 0.45 μm filter paper to obtain an ink composition of the present example.
EXAMPLE 16
[0041] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 13, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 6.
EXAMPLE 17
[0042] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 13, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 8.
EXAMPLE 18
[0043] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 13, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 9.
EXAMPLE 19
[0044] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 13, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 10.
EXAMPLE 20
[0045] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 13, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 11.
EXAMPLE 21
Preparation of an Ink Composition
[0046] 9 parts of the dye composition prepared in Example 1, 6 parts of the dye composition prepared in Example 2, 10 parts of N-methyl-2-pyrrolidone (component (C)), 10 parts of 2-pyrrolidone (component (C)), 0.5 parts of surfactant Surfynol 465 (component (E)), 0.2 parts of microbicide Proxel XL2 (component (F)), and water (component (D)), in the sum of 100 parts, are mixed by a mixing machine for 30 min. 5 Then, absolute filtration was performed on the mixture with 0.45 μm filter paper to obtain an ink composition of the present example.
EXAMPLE 22
[0047] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 21, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 5, and the dye composition prepared in Example 2 was substituted with the dye composition prepared in Example 4.
EXAMPLE 23
[0048] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 21, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 6, and the dye composition prepared in Example 2 was substituted with the dye composition prepared in Example 7.
EXAMPLE 24
[0049] The method for preparing the ink composition of the present example was the same with the method illustrated in Example 21, except that the dye composition prepared in Example 1 was substituted with the dye composition prepared in Example 8, and the dye composition prepared in Example 2 was substituted with the dye composition prepared in Example 12.
COMPARATIVE EXAMPLE 1
Preparation of a Dye Composition
[0050] 100 parts of Reactive Red 180 (commercially available form Everlight Chemical Industrial Corp.) was mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of the compound of the formula (II-1) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition.
COMPARATIVE EXAMPLE 2
Preparation of a Dye Composition
[0051] 50 parts of the compound of the formula (I-1), and 50 parts of the compound of the formula (I-2) were mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, the pH value of the resulted solution was adjusted to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition.
COMPARATIVE EXAMPLE 3
Preparation of a Dye Composition
[0052] 100 parts of the compound of the formula (I-4) was mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, the pH value of the resulted solution was adjusted to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition.
COMPARATIVE EXAMPLE 4
Preparation of a Dye Composition
[0053] 50 parts of the compound of the formula (I-1), and 50 parts of the compound of the formula (I-2) were mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of N,N-diethylaniline sulfonic acid (DEAS) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition.
COMPARATIVE EXAMPLE 5
Preparation of a Dye Composition
[0054] 50 parts of the compound of the formula (I-4) was mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of N,N-diethylaniline sulfonic acid (DEAS) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition.
COMPARATIVE EXAMPLE 6
Preparation of a Dye Composition
[0055] 50 parts of the compound of the formula (I-1), and 50 parts of the compound of the formula (I-2) were mixed with 300 parts of water, followed by adjusting the pH value of the resulted solution to 6-8. Reverse osmosis was performed to remove the salts from the resulted solution, and the content of salt is less than 0.5% by weight after desalination. Then, 2 parts of sodium tripolyphosphate (STPP) was added into the resulted solution, followed by mixing and adjusting the pH value to 6.5-7.5. Finally, the resulted solution was dried by spray drying to obtain a dye composition.
COMPARATIVE EXAMPLE 7
Preparation of an Ink Composition
[0056] 15 parts of the dye composition prepared in Comparative example 1, 10 parts of N-methyl-2-pyrrolidone, 10 parts of 2-pyrrolidone, 0.5 parts of surfactant Surfynol 465, 0.2 parts of microbicide Proxel XL2, and water, in the sum of 100 parts, are mixed by a mixing machine for 30 min. Then, absolute filtration was performed on the mixture with 0.45 μm filter paper to obtain an ink composition.
COMPARATIVE EXAMPLE 8
[0057] The method for preparing the ink composition of the present comparative example was the same with the method illustrated in Comparative example 7, except that the dye composition prepared in Comparative example 1 was substituted with the dye composition prepared in Comparative example 2.
COMPARATIVE EXAMPLE 9
[0058] The method for preparing the ink composition of the present comparative example was the same with the method illustrated in Comparative example 7, except that the dye composition prepared in Comparative example 1 was substituted with the dye composition prepared in Comparative example 3.
COMPARATIVE EXAMPLE 10
[0059] The method for preparing the ink composition of the present comparative example was the same with the method illustrated in Comparative example 7, except that the dye composition prepared in Comparative example 1 was substituted with the dye composition prepared in Comparative example 4.
COMPARATIVE EXAMPLE 11
[0060] The method for preparing the ink composition of the present comparative example was the same with the method illustrated in Comparative example 7, except that the dye composition prepared in Comparative example 1 was substituted with the dye composition prepared in Comparative example 5.
COMPARATIVE EXAMPLE 12
[0061] The method for preparing the ink composition of the present comparative example was the same with the method illustrated in Comparative example 7, except that the dye composition prepared in Comparative example 1 was substituted with the dye composition prepared in Comparative example 6.
Test Result
(1) Spray Drying Test on the Dye Composition
[0062] The dye composition prepared in Examples 1-12 and Comparative examples 1-5 were tested by drying through spray drying under high temperature, and the changes in the pH value of these dye compositions were measured. The test results are listed in following Table 1.
[0000]
TABLE 1
Changes in the pH value of the dye compositions
before and after spray drying
Spray drying
Tempera-
Tempera-
pH
ture of
ture of
pH
pH
No.
(Liq)
the outlet
the inlet
(Powder)* 1
difference* 2
Example 1
7.0
130° C.
220° C.
6.8
0.2
Example 2
7.0
130° C.
220° C.
6.5
0.5
Example 3
7.0
130° C.
220° C.
6.6
0.4
Example 4
7.0
130° C.
220° C.
6.8
0.2
Example 5
7.0
130° C.
220° C.
6.8
0.2
Example 6
7.0
130° C.
220° C.
6.7
0.3
Example 7
7.0
130° C.
220° C.
6.8
0.2
Example 8
7.0
130° C.
220° C.
6.7
0.3
Example 9
5.0
130° C.
220° C.
5.0
0.0
Example 10
7.0
130° C.
220° C.
7.0
0.0
Example 11
7.0
130° C.
220° C.
6.9
0.1
Example 12
7.0
130° C.
220° C.
7.0
0.0
Comparative
7.0
130° C.
220° C.
5.9
1.1
example 1
Comparative
7.0
130° C.
220° C.
4.7
2.3
example 2
Comparative
7.0
130° C.
220° C.
5.5
1.5
example 3
Comparative
7.0
130° C.
220° C.
5.6
1.4
example 4
Comparative
7.0
130° C.
220° C.
5.8
1.2
example 5
* 1 pH (Powder): The pH value of a dye solution of 1% by weight, which is prepared by mixing 1 g of a dried dye composition with water.
* 2 pH difference: The difference in the pH value of the dye solution before and after spray drying.
[0063] From the results shown in Table 1, the pH values of all the dye compositions prepared in Examples of the present invention can maintain stable, during the process of spray drying from 220° C. to 130° C. Therefore, the dye compositions of the present invention are suitable for preparing an ink composition for digital textile printing. However, the pH differences of the dye compositions prepared in Comparative examples are much larger than the pH differences of the dye compositions prepared in Examples, which means that the dye compositions prepared in Comparative examples have poor stability. Therefore, the dye compositions prepared in Comparative examples are not suitable for preparing an ink composition for digital textile printing.
(2) Comparison of Quality of the Ink Composition for Digital Textile Printing
[0064] (a) The ink composition prepared by Examples 13-24 and Comparative examples 7-12 were printed on pretreated textiles.
[0065] The textile used herein is a woven fabric. Before printing, the woven fabric was treated with a treatment solution, pick-up 70%, by pad-roll process, followed by drying by heat.
[0000] Treatment solution Sodium alginate 6 wt % Urea 10 wt % Reduction inhibitor 1 wt % Sodium bicarbonate 2 wt % Water 81 wt % 100 wt %
(b) The resulted pictures were treated through the following method:
[0066] The textiles printed with the ink composition of Examples 13-24 and Comparative examples 7-12 were dried under 80° C. for 5 min, and then the textiles were brought to fixation in 102-110° C. steam for 8-15 min. The textiles were washed with 100C. solution containing a certain ratio of detergent, respectively. After drying, the tests on printability, time-dependent printability, relative strength, and color deterioration were performed, and the results are listed in following Table 2. “Printability” means the printing condition of the ink composition; “time-dependent printability” means the printing condition of the ink composition, which is stored under 50° C. for 2 weeks; “relative strength” means the color strength comparison of the printing after washing, wherein the printing is obtained from the tests on printability and time-dependent printability; and “color deterioration” means a relative degree of deterioration between the color strength of the ink composition stored under 50° C. for 2 weeks (i.e. test on “time-dependent printability”) and the color strength of the original ink composition (i.e. test on “printability”).
[0000]
TABLE 2
Test results of the ink compositions for digital textile printing
Time-
dependent
Relative
Color
No.
Printability* 1
printability* 1
strength* 2
deterioration* 2
Example 13
⊚
⊚
97%
−3%
Example 14
⊚
⊚
100%
−0%
Example 15
⊚
⊚
96%
−4%
Example 16
⊚
⊚
97%
−3%
Example 17
⊚
⊚
98%
−2%
Example 18
⊚
⊚
100%
−0%
Example 19
⊚
⊚
97%
−3%
Example 20
⊚
⊚
98%
−2%
Example 21
⊚
⊚
95%
−5%
Example 22
⊚
⊚
96%
−4%
Example 23
⊚
⊚
98%
−2%
Example 24
⊚
⊚
98%
−2%
Comparative
◯
X
—
—
example 7
Comparative
◯
X
86%
−14%
example 8
Comparative
◯
X
85%
−15%
example 9
Comparative
⊚
◯
90%
−10%
example 10
Comparative
⊚
◯
91%
−9%
example 11
Comparative
◯
X
—
—
example 12
* 1 ⊚ means 0-5 nozzles are clogged after printing continuously for 1 hour, i.e. good printability; ◯ means 6-15 nozzles are clogged after printing continuously for 1 hour, i.e. normal printability; and X means more than 15 nozzles are clogged after printing continuously for 1 hour, i.e. poor printability.
* 2 After the test on printability is performed, the color strength of the printing is regarded as 100%, wherein — means poor printability of the ink composition so that it is impossible to measure the relative strength of the printing.
[0067] From the results shown in Table 2, any kinds of the ink composition prepared in Examples of the present invention shows good “printability” and “time-dependent printability”. Furthermore, the ink compositions prepared in Examples of the present invention also have good stability under high temperature.
[0068] The ink composition for digital textile printing, which is prepared by the dye composition of the present invention, has excellent “printability” and “time-dependent printability”, and the color deterioration in color strength can be controlled within 5%. Furthermore, the ink composition prepared by the dye composition of the present invention can be printed on cellulose fibers, and the regeneration fibers thereof, including cotton, rayon, and natural fibers, such as silk or wool.
[0069] In conclusion, the present invention is different from the prior arts in several ways, such as in purposes, methods and efficiency, or even in technology and research and design. Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.
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The present invention relates to a novel ink composition and, more particularly, to an ink composition for digital textile printing, which is suitable for ink-jet printing on cellulose fiber materials. The novel ink composition of the present invention has stable pH value, fine storage stability, smoothness and ease in printing, and reduction in color deterioration.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of PCT Application No. PCT/EP2005/053679, filed Jul. 28, 2005, the disclosure of which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to apparatuses for the soft machining of bevel gears, especially apparatuses designed for dry machining. The invention also relates to a respective method.
There are various machines which are used in the production of bevel gears and similar gearwheels. There has been a desire for some time to automate the production. One solution that has made only limited headway is a machining center which is designed in such a way that a large number of production steps can be performed on one and the same machine. Such machines are not only very complex and therefore expensive, but also require a relatively large amount of work in preparatory setup (setup time). On the other hand, such machines that were developed with a view to high flexibility are rather suited for individual productions or very small series.
The European patent EP 0 832 716 B1 shows and describes a compact machine which is designed for turning and gear hobbing a workpiece, with said workpiece not having to be re-chucked or transferred. In other words, the workpiece sits on a main spindle after chucking and is machined there with different tools. It is regarded as a disadvantage that as a result of the arrangement of the different elements it is not designed to carry out dry machining since the removal of the hot chips is especially relevant in dry machining. Moreover, the freedom of movement is limited with respect to the workpiece as a result of the lateral arrangement of the two carriages with the tools. The shown machine is not suitable for machining bevel gears or the like, but is designed for machining cylinder gears.
SUMMARY OF THE INVENTION
The invention is based on the object of simplifying the production of bevel gears.
It is a further object of the invention to provide a respective apparatus which is inexpensive.
These objects are achieved in accordance with the invention by an apparatus ( 20 ) comprising:
a turning machine ( 22 ) having a working spindle ( 22 . 1 ) and a counter-holder ( 23 ) arranged coaxially to a rotational axis (B 1 ) of the working spindle ( 22 . 1 ) for coaxially clamping a workpiece blank (K 1 ); a tool base ( 24 ) which is displaceable relative to the workpiece blank (K 1 ) held in the turning machine ( 22 ) and comprises a multifunctional tool holder ( 25 ) mounted to rotate about an axis (B 2 ) extending substantially parallel to the rotational axis (B 1 ) of the working spindle ( 22 . 1 ), with the multifunctional tool holder ( 25 ) being configured for fastening at least one tool ( 25 . 1 - 25 . 4 );
a tool housing ( 26 ) displaceable relative to the workpiece blank (K 1 ) held in the turning machine ( 22 ); characterized in that:
the tool housing holds a milling head ( 27 ) rotatable about a milling head axis (B 3 ) with a set of axially extending cutters chucked in the tool housing ( 26 ); the milling head ( 27 ) is mounted at an adjustable angle (W) respective to the rotational axis (B 1 ) of the working spindle ( 22 . 1 ); and the milling head ( 27 ) is equipped with a set of cutters protruding from an axial end face thereof with respect to said milling head axis (B 3 ), the tool housing ( 26 ) also being arranged to advance the milling head ( 27 ) towards the workpiece blank (K 1 ) to machine the workpiece blank (K 1 ), a CNC controller ( 28 ) for controlling different movement processes of the tool base ( 24 ) and the tool housing ( 26 ) in order to subject the workpiece blank (K 1 ) firstly to a turning process with a tool fixed to the tool base ( 24 ) and then to a tooth machining process with the milling head ( 27 ) to produce a bevel gear from the workpiece blank (K 1 ). These objectives are also achieved by a method for soft machining of bevel gears, comprising the following steps:
a) clamping of a workpiece blank (K 1 ) on a first workpiece spindle ( 22 . 1 ) of a turning machine ( 22 ) which comprises a counter-holder ( 23 ) for coaxially clamping the workpiece blank (K 1 ), which counter-holder is arranged coaxially to a rotational axis (B 1 ) of the workpiece spindle ( 22 . 1 );
b) performing a turning machining with a tool fastened to the tool base ( 24 ), with the turning machine ( 22 ) comprising the tool base ( 24 ) which is movable relative to the workpiece blank (K 1 ) clamped in the turning machine ( 22 ) and comprising a multifunctional tool holder ( 25 ) being rotatably held about an axis (B 2 ) which extends substantially parallel to the rotational axis of the first workpiece spindle (B 1 ), with the multifunctional tool holder ( 25 ) being configured for fastening the tool;
c) performing gear-tooth forming with a milling head ( 27 ), with the turning machine ( 22 ) comprising a tool housing ( 26 ) for the milling head ( 27 ) and the tool housing ( 26 ) is movable relative to the workpiece blank (K 1 ) clamped in the turning machine ( 22 ) and the milling head ( 27 ) is rotatably held about a machining head axis (B 3 ) at an adjustable angle (W) respective to the rotational axis (B 1 ) of the working spindle ( 22 . 1 ).
The apparatus in accordance with the invention is relatively inexpensive and can therefore be used in situations where complex and therefore often expensive machine tools are not economical. The method in accordance with the invention is especially designed for machining tooth flanks prior to a hardening process, i.e. in the soft state. The tools which are used must be chosen accordingly.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are described in closer detail by reference to the drawings, wherein:
FIG. 1 shows a schematic view of the various machining steps in producing bevel gears;
FIG. 2 shows a schematic view of a first apparatus for use in soft machining of bevel gears in accordance with the invention;
FIG. 3 shows a schematic view of a second apparatus for use in soft machining of bevel gears in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Terms will be used in connection with the present description, which are also used in relevant publications and patents. Notice shall be taken however that the use of such terms shall merely serve better understanding. The inventive idea and the scope of protection of the claims shall not be limited in their interpretation in any way by the specific choice of the terms. The invention can easily be transferred to other terminological systems and/or specialist fields. The terms shall apply analogously in other specialist fields.
In accordance with the invention, the machining of bevel gears is concerned. This term shall also include crown wheels and bevel pinions, according to definition. It also includes bevel gears without axial offset and bevel gears with axial offset, so-called hypoid bevel gears.
FIG. 1 shows a schematic view of an exemplary process run 10 . The invention can be used advantageously in the shown context. As was already mentioned, it concerns an example for machining a bevel gear. Based on a workpiece blank (box 101 ), the following soft machining steps are performed in the illustrated example. Based on a workpiece blank (box 101 ), the following soft machining steps are performed in the illustrated example. A (central) bore can be produced by drilling for example (box 102 ). The workpiece blank can then be machined by turning (box 103 ) with a lathe tool. These steps are referred to in this context as preform production or pre-machining. Other steps or alternative steps can be carried out within the scope of preform production. The workpiece is referred to as a gear blank at the end of preform production.
This is followed by the so-called gear-tooth forming. In accordance with the invention, preferably (dry) bevel gear milling (box 104 ) is used in order to produce teeth in the gear blank. This is followed by trimming as an optional step (box 105 ). The steps 102 , 103 and 104 or the steps 102 to 105 can be carried out in accordance with the invention in an apparatus 20 in accordance with the invention.
This is typically followed by heat treatment (box 106 ) in order to harden the gear blank and by aftertreatment or finishing (box 107 ). The bevel gear is then finished.
Further details of the invention are described below by reference to a more detailed description of the individual method steps and by means of an embodiment.
The method in accordance with the invention for soft machining of bevel gears comprises the following steps. The reference numerals relate to FIG. 2 . A workpiece blank K 1 is clamped in a first working spindle 22 . 1 of a turning machine 22 which is part of the apparatus 20 in accordance with the invention. A first soft machining of the workpiece blank K 1 is performed with one or several tools 25 . 1 , 25 . 2 , 25 . 3 . The tool or tools 25 . 1 , 25 . 2 , 25 . 3 are clamped in a first multifunctional tool holder 25 of apparatus 20 . This first soft machining can concern one or several of the following machining steps: drilling, turning, milling. The goal of this first soft machining is to produce a gear blank from the workpiece blank K 1 .
The gear-tooth forming is now also carried out in the same apparatus 20 . This occurs as follows. A second soft machining of the gear blank is performed with a milling head 27 which is chucked on a tool housing 26 . The goal of said second soft machining is to produce a gearing on the gear blank. Preferably, the second soft machining comprises the (dry) bevel gear milling of the gear blank by means of a milling head 27 .
In order to perform said steps in the mentioned manner, the multifunctional tool holder 25 is located on the tool base 24 and the milling head 27 on the tool housing 26 in a horizontal plane relative to the main axis B 1 of the turning machine 22 . The tool base 24 is preferably located on the one side and the tool housing 26 on the other side next to axis B 1 .
Preferably, all machining steps can be carried out in a dry manner. In this case, however, it is necessary to configure and arrange the apparatus 20 accordingly, especially in order to enable the removal of the hot chips.
The apparatus 20 in accordance with the invention is shown in FIG. 2 . The apparatus 20 is specially designed for use in soft machining of bevel gears and comprises a CNC-controlled turning machine 22 with a working spindle 22 . 1 for receiving the workpiece blank K 1 . The apparatus 20 comprises a tool base 24 with different tools 25 . 1 to 25 . 3 and a tool housing 26 for receiving the gearing tool (a milling head 27 for example) for gear-tooth forming the gear blank. A counter-holder 23 can also be provided.
In accordance with the invention, the apparatus 20 concerns a horizontally operating machining station on the basis of a turning machine in which the tool housing 26 with the milling head 27 is arranged to the side of the working spindle 22 . 1 with the gear blank during the gear-tooth forming. (It is also possible to provide a vertical configuration with a similar overall arrangement.)
In accordance with the invention, the turning machine 22 forms a functional unit in combination with the tool housing 26 , in which the workpiece blank K 1 is subjected to a first soft machining in order to be subjected to gear forming after the first soft machining as a gear blank by the milling head 27 . The apparatus 20 has a CNC controller 28 which is indicated in FIG. 2 . The CNC controller 28 is linked by control at least with the following parts of the system 22 , 24 , 25 , 26 , which is indicated in FIG. 2 by the arrows 28 . 1 . This linkage can also be made via a bus or via a cable connection. It is also possible to use another kind of the interface, e.g. a wireless connection, in order to link the CNC controller 28 with the individual system parts 22 , 24 , 25 , 26 .
Further details of the apparatus 20 shown in FIG. 2 will be explained below. The turning machine 22 has a main rotational axis B 1 . The working spindle 22 . 1 can be rotated about said axis B 1 , as is indicated by the double arrow 29 . 1 . Furthermore, the counter-holder 23 sits coaxially to the working spindle 22 . 1 on a carriage 23 . 1 and can be displaced in the longitudinal direction to the main rotational axis B 1 , as indicated by arrow x 1 . In addition, the tool base 24 has a rotational axis B 2 . The tool holder 25 can be rotated about said axis B 2 , as is indicated by the double arrow 29 . 2 . In the illustrated embodiment, the tool base 24 sits on a carriage 24 . 1 , 24 . 2 and can thus be displaced together with the tool 25 . 1 , 25 . 2 , 25 . 3 in the axes x 2 , y 2 . A drive 24 . 3 is connected with the carriages 24 . 1 , 24 . 2 and the tool holder 25 to enable advancing various tools ( 25 . 1 , 25 . 2 , 25 . 3 ) with respect to the workpiece blank (K 1 ) by rotation of the tool holder ( 25 ) about its axis (B 2 ) extending substantially parallel to the rotational axis (B 1 ) of the working spindle ( 22 . 1 ) and by translatory movements of the tool base ( 24 ).
The milling head 27 can rotate about axis B 3 , as indicated by the double arrow 29 . 3 . Furthermore, the tool housing 26 sits on a carriage 26 . 1 , 26 . 2 and can be displaced in different directions, as is indicated by arrows x 3 , y 3 .
In the illustrated embodiment, the working spindle 22 . 1 plus workpiece blank K 1 and/or gear blank cannot be displaced in a translatory manner. The displacing capability parallel to the to the axis x 1 is not necessary in a mandatory fashion because the tool 25 . 1 , 25 . 2 , 25 . 3 and the milling head 27 can be advanced in that the tool base 24 or the tool housing 26 are displaced parallel to the axis x 1 . A displacement of the turning machine 22 in the plane of projection perpendicular to the axis x 1 is also not necessary in a mandatory manner because the tool base 24 and the tool housing 26 can be displaced in the y-direction y 2 , y 3 . The working spindle 22 . 1 can still be arranged on a carriage in order to gain further degrees of freedom.
The different axes concern numerically controlled axes. As a result, the individual movements can be controlled numerically by the CNC controller 28 . Preferably, the controller 28 is arranged in such a way that all axes can be controlled numerically. Important is, that every single one of the movement sequences occurs in a coordinated manner. Said coordination is carried out by the CNC controller 28 .
The apparatus 20 in accordance with the invention is thus special and thus stands out from other known approaches in that the individual machining stations 24 , 26 are arranged horizontally. Moreover, the position of the different numerically controlled axes was chosen in such a way that there is the highest possible range for movement for machining the workpiece/blank. The following arrangement of the individual axes is especially preferred.
Tool base 24 : Axis x 2 extends parallel to the axis x 1 , with the two axis being offset against one another in that a relative movement parallel to the y 2 direction is performed. In this way it is possible for example to machine a central bore in the workpiece blank K 1 with a drill 25 . 3 . The tool base 24 plus carriage 24 . 1 , 24 . 2 is arranged adjacent to the working spindle 22 . 1 and it is possible to change the relative distance to one another in that relative displacements are made parallel to x 2 and/or y 2 . Preferably, the two axes x 1 , x 2 can also be offset against one another in the depth (perpendicular to the plane of projection). For this purpose, the carriage 24 . 1 , 24 . 2 can be displaced parallel to an optional z 2 axis.
Tool housing 26 with milling head 27 : Axis x 3 preferably extends parallel to the axis x 1 . The tool housing 26 plus carriage 26 . 1 , 26 . 2 is also arranged horizontally to the working spindle 22 . 1 and the relative distance towards one another can be changed in that a relative displacement is performed parallel to the x 3 , y 3 axes. The two axes x 1 , x 3 can preferably be offset against another laterally (in the plane of projection). Carriage 26 . 1 can be displaced parallel to the y 3 axis for this purpose. Preferably, the two axes x 1 , x 3 can also be offset against each other in the depth (perpendicular to the plane of projection). Carriage 26 . 1 , 26 . 2 can be displaced parallel to an optional z 3 axis for this purpose.
It is also possible to associate the tool housing 26 with milling head 27 to another system of coordinates and to arrange the axes of such system of coordinates differently. In this case, the CNC controller 28 needs to take a coordinate transformation into account in order to enable the coordination of sequences of movements between the different coordinate systems.
During the gear-tooth forming, an angle W can be set and changed between the two axes B 1 and B 3 , as shown in FIG. 2 where the angle is approximately 40°. An angular adjustability in the range from W 1 to W 2 is preferably possible. W is usually not set to a fixed value, but is changed during the milling.
According to an embodiment of the invention, the working spindle 22 . 1 for receiving the workpiece blank K 1 comprises a clamping or grasping means in order to enable clamping of the workpiece blank/gear blank. An embodiment is especially preferable where the clamping or grasping means is designed for automatic mounting.
The tool base 24 of apparatus 20 is preferably equipped with a tool turret 25 . 2 which can receive several tools. An embodiment is especially preferable in which at least one of the tools which is located in the multifunctional tool head 25 or in the tool turret 25 . 2 can be driven individually. The tool turret 25 . 2 itself can be rotated about an axis B 4 , as indicated by the double arrow 25 . 4 .
The tool base 24 can be used for turning, fluting, drilling, etc.
The multifunctional tool holder 25 shows in the illustrated embodiment several tool holders. Three tools 25 . 1 to 25 . 3 are present in the illustrated embodiment. The multifunctional tool holder 25 is preferably arranged in such a way that at least one of the tool holders is arranged as a spindle head in order to enable driving the respective tool individually. The tool 25 . 3 can concern a drill or a milling head which can be made to rotate about its longitudinal axis. The tools 25 . 1 and 25 . 2 can be tool turrets, lathe tools or deburring heads which are each fixedly clamped in a tool holder of the multifunctional tool holder 25 .
The apparatus 20 can be modified and adjusted to the parameters accordingly.
An apparatus 20 is especially preferable which is characterized in such a way that the apparatus 20 comprises a CNC controller 28 which is designed in such a way that the turning machine 22 , the tool base 24 and the tool holder 25 can be operated as a functional unit together with the tool housing 26 . The advantage of the fact that there is only one CNC controller which is located in the turning lathe 21 or is designed for operation with the lathe 21 is that the apparatus 20 can thus be realized in a more cost-effective way. These savings in cost are mainly realized in such a way that bevel gear milling with the milling head 27 does not require a separate CNC controller 28 . Moreover, the linkage of the axes is less complex and the coordination of the individual sequences of movements on apparatus 20 will become simpler.
A further embodiment is shown in FIG. 3 . This embodiment is based on the principle of the invention as described above. Insofar as useful, the same reference numerals will be used in FIG. 3 .
FIG. 3 shows an apparatus 30 in which the multifunctional tool holder 34 also acts as a tool housing 36 for a milling head 27 . The carriage 24 . 2 can be rotated about a perpendicular axis B 5 , as indicated by the double arrow 29 . 3 . The milling head 27 can thus be turned to position 27 ′ as shown schematically in FIG. 3 . Bar cutters on the milling head 27 can then perform the milling of the gear blank K 1 . During this milling, both the milling head 27 is turned about its axis B 3 as well as the gear blank about the axis B 2 . During machining by turning, which precedes milling for example, one of the other tools 25 . 1 or 25 . 3 can be used. Control is carried out by a CNC controller 38 which is provided with a different configuration than the controller 28 in FIG. 2 due to the slightly different arrangement of the axes and the integration of the milling head 27 in the tool holder 34 .
An embodiment is especially preferable in which the tool housing 26 , 36 or 46 is configured for dry milling of bevel gears or milling with minimal quantities of lubricant (MQL).
Tools made of high-duty steel, hard metal, ceramics or cermet (combination of metal and ceramics) with a respectively suitable hard solid coating are used according to the invention for gear-tooth machining by bevel gear mills depending on the hardness of the tool.
It is regarded as an advantage of the present invention that a workpiece, without having to be re-chucked, can be machined from the blank to the finished bevel gear. It thus concerns a virtually very compact production line which through special measures can be realized in the smallest possible space and made available at affordable prices.
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The invention relates to a device for use in production of bevel gears. The device comprises a turning machine ( 22 ), with a working spindle ( 22.1 ) and a counter-holder ( 23 ), arranged co-axially to a rotational axis (B 1 ) of the working spindle ( 22.1 ) for the coaxial tensioning of a workpiece blank (K 1 ). A multi-functional tool holder ( 24 ) is provided, which may be displaced relative to the workpiece blank (K 1 ) held in the turning machine ( 22 ) and comprises a tool base ( 25 ) mounted to rotate about an axis (B 2 ). The tool base ( 25 ) is provided for fixing one or more tools. A tool housing ( 26 ) with milling head ( 27 ) is provided, the tool housing ( 26 ) being displaceable relative to the workpiece blank (K 1 ) held in the turning machine ( 22 ) and the milling head ( 27 ) is mounted to rotate about a milling head axis (B 3 ). A controller is provided for control of the movement processes, to subject the workpiece blank (K 1 ) firstly to a turning process with a tool fixed to the tool base ( 25 ) and then a toothing machining with the milling head ( 27 ).
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BACKGROUND OF THE INVENTION
[0001] This invention relates to a quick connect fitting for dividing the flow from a stub-out.
[0002] Current practice during building construction is to complete the rough-in plumbing and provide a stub-out pipe so that the rough-in plumbing may be checked for leaks, etc. The stub-out pipe is generally a small diameter pipe. After capping the stub-out pipe and checking for leaks, plumbers connect a plumbing fixture, such as a dishwasher or a faucet, to the stub-out pipe. Often, it is desirable to connect more than one fixture near the location of a single stub-out and to divide the flow from a single stub-out.
[0003] Stub-outs are frequently located under kitchen cabinets and other cramped areas. The stub-outs are sometimes difficult to connect to fixtures, especially if using adhesive or fusion bonding between the stub-out and the plumbing from the stub-out to the fixture. Further, these traditional plumbing means are often time consuming, require several additional tools, and are difficult to verify.
SUMMARY
[0004] An example quick connect fitting assembly includes a fitting for communicating flow between at least three openings. A quick connect portion of the fitting defines one of the openings. The quick connect portion is for connecting the fitting to a conduit.
[0005] The example quick connect fitting assembly may include a fitting for communicating flow from a stub-out conduit between at least three openings within the fitting. A quick connect includes a mount housing having a multitude of fingers defined about an axis and a slot generally transverse to the axis. The quick connect further includes a retainer mountable within the slot. The retainer has a set of conduit attachment legs and a set of housing attachment legs defined within a common plane. The set of housing attachment legs engages a surface within the slot to retain the stub-out conduit within the mount housing.
[0006] The example quick connect fitting may include a quick connect assembly having a mount housing and a retainer. The mount housing has a multitude of circumferential fingers defined about an axis and a slot generally transverse the axis. The retainer mounts at least partially within the slot. The retainer has a set of conduit attachment legs and a set of housing attachment legs defined within a common plane. The set of housing attachment legs engages a corresponding surface within the slot to retain the retainer within the mount housing. The quick connect assembly is securable to a conduit adjacent an opening within the conduit. The conduit is for communicating flow between at least three conduit openings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description:
[0008] FIG. 1 is a general perspective view of an example quick connect fitting assembly;
[0009] FIG. 2 is another perspective view of the FIG. 1 quick connect fitting assembly engaging two stops and a stub-out conduit;
[0010] FIG. 3 is an exploded view of the FIG. 1 quick connect fitting assembly;
[0011] FIG. 4 is a side view of the FIG. 1 quick connect fitting assembly;
[0012] FIG. 5A is a sectional view of the FIG. 1 quick connect fitting assembly taken along the length thereof in an unlocked position;
[0013] FIG. 5B is a sectional view of the FIG. 1 quick connect fitting assembly taken along the length thereof in a locked position; and
[0014] FIG. 6 is a sectional view taken at line 3 D- 3 D in FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIG. 1 shows an example quick connect fitting assembly 20 having a fitting portion 24 and a quick connect portion 28 . In this example, the fitting assembly 20 moves flow between three openings 30 a , 30 b , 30 c . The quick connect portion 28 defines the opening 30 a , and the fitting assembly 20 includes two extensions 34 each defining one of the other openings 30 b , 30 c.
[0016] Referring now to FIG. 2 with continuing reference to FIG. 1 , the quick connect portion 28 of the fitting assembly 20 engages a stub-out conduit 38 . Flow of water, for example, moves through the stub-out conduit 38 in a known manner. The fitting portion 24 divides flow from the stub-out conduit 38 directing some of the flow through the opening 30 b and some of the flow through the opening 30 c . In this example, stops 42 engage each of the extensions 34 . The stops 42 each include a valve 46 for controlling flow from the stop openings 50 . Turning the valves 46 controls flow through the stop openings 50 in a known manner. Although the fitting assembly 20 is generally described as controlling flow moving from the stub-out conduit 38 , other examples may include controlling flow moving from the fitting assembly 20 .
[0017] In this example, a Y axis defined by the extensions 34 is perpendicular to the axis X defined by the quick connect portion 28 and the opening 30 a associated with the quick connect portion 28 . Accordingly, the example fitting assembly 20 has a general T profile. As the openings 30 a , 30 b , 30 c are defined either by the quick connect portion 28 or the extension 34 for receipt within a quick connect portion of another plumbing device, the fitting assembly 20 divides flow between the openings 30 a , 30 b , 30 c without threaded fasteners or adhesives.
[0018] Referring now to FIGS. 3 and 4 , the quick connect portion 28 of the quick connect fitting assembly 20 generally includes an anti-rotation disc 54 , an anti-rotation spacer 58 , a first o-ring seal 62 , a spacer 66 , a second o-ring seal 70 , a mount housing 74 , and a retainer 78 , which fits within a mount housing slot 74 s . In this example, the quick connect portion 28 is attachable to the stub-out conduit 38 without adhesive or welding.
[0019] The stub-out conduit 38 generally defines a smaller diameter 82 and a larger diameter 86 , which together adapt the stub-out conduit 38 for receipt within the quick connect portion 28 . The smaller diameter 82 defines an attachment groove 90 for receipt of the retainer 78 . An internal structure 94 , such as a multitude of splines, are engageable with the anti-rotation disc 54 to rotationally fix the fitting assembly 20 on the stub-out conduit 38 .
[0020] The extensions 34 include structures similar to the stub-out conduit 38 . That is, the extensions 34 each include a diameter 98 defining a groove 102 and an internal structure 104 . Such geometry facilitates receipt and retention of the extensions 34 within the quick connect portion of another plumbing device, such as the stops 42 of FIG. 2 . In this example, the fitting assembly 20 provides two extensions 34 suitable for engagement by other quick connect plumbing devices. As known, the stub-out conduit 38 is engageable by only the one quick connect portion 28 .
[0021] Referring to FIGS. 5A and 5B , the mount housing 74 includes a multitude of circumferential fingers 106 defined about a longitudinal axis X. Each finger 106 includes a barbed end 108 ( FIG. 3 ). The barbed end 108 engages a corresponding internal groove 112 within the fitting portion 24 . The barbed end 108 further defines a stop surface 116 , which axially retains the o-ring seal 70 , the spacer 66 , and the o-ring seal 62 within the fitting portion 24 . The mount housing 74 fits over the smaller diameter 82 and the retainer 78 aligns with the attachment groove 90 .
[0022] As shown in FIG. 6 , the retainer 78 includes a partially annular set of conduit attachment legs 120 and a set of housing attachment legs 124 . The conduit attaching legs 120 and the housing attachment legs 124 are defined within a common plane P ( FIG. 5 ). The conduit attachment legs 120 engage the attachment groove 90 to axially retain the stub-out conduit 38 therein. The housing attachment legs 124 each include a barbed end 128 , which engage a corresponding surface 132 located within the slot 74 s.
[0023] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
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An example quick connect fitting assembly includes a fitting for communicating flow between at least three openings. A quick connect portion of the fitting defines one of the openings. The quick connect portion is for connecting the fitting to a conduit
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RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP2007-259254 filed Oct. 2, 2007, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a device for supporting a diagnosis of a cancer and a device for predicting an effects of anthracycline anticancer drugs.
[0003] Chemotherapy, that is, treatment by anticancer drugs is being conventionally carried out at one of the treatment methods on cancer patients. The treatment by anticancer drugs is an extremely useful treatment method to suppress the progress of cancer and to suppress recurrence of cancer, but also involves risks of side effects.
[0004] With anticancer drugs, it is known that its effectiveness differs by individual patients, and although some patients take the risk of side effects, great number of patients who cannot sufficiently obtain the anticancer effect from the anticancer drugs exist. In order to solve such problem, various proposals have been made for predicting the effectiveness (sensitivity) of the anticancer drugs in a cancer patient and providing a maximum anticancer drug treatment while avoiding the risk of unnecessary side effects.
[0005] In US 2006/0173632, US 2007/0003438, or US 2007/231837, a method of determining sensitivity of the taxane anticancer drugs based on the activity value and the expression level of the cyclin-dependent kinase (CDK) is disclosed.
[0006] It is also known that anticancer drugs have different effects on the living body depending on the type. For instance, the taxane anticancer drug stops the mitotic division of cells by stabilizing the microtubules in the cell in a polymerized state, and induces apoptosis. The main side effects of the taxane anticancer drug are known as peripheral neuritis. The drugs having the effect of inhibiting the topoisomerase include anthracyclinee anticancer drugs. The anthracyclinee anticancer drugs is an anticancer drug having a strong aggressiveness to directly break the DNA, and involves major side effects such as breaking of myocardial cell membrane and congestive failure. Thus, it is particularly important to predict the sensitivity of the anthracyclinee anticancer drugs in the cancer treatment using the anthracyclinee anticancer drugs.
BRIEF SUMMARY
[0007] A first aspect of the invention is a device for supporting a diagnosis of a cancer comprising: acquiring means for acquiring a first cyclin dependent kinase (first CDK) parameter which is capable to be acquired from an activity value and an expression level of the first CDK, and a second cyclin dependent kinase (second CDK) parameter which is capable to be acquired from an activity value and an expression level of the second CDK, based on an activity value and an expression level of the first CDK contained in a first malignant tumor of a cancer patient to be examined and on an activity value and an expression level of the second CDK contained in the first malignant tumor; a memory storing a plurality of sample data, each of the sample data comprising: a first CDK parameter acquired from an activity value and an expression level of the first CDK contained in a second malignant tumor of a sample patient, to whom anthracyclinee anticancer drugs have been administered; a second CDK parameter acquired from an activity value and an expression level of the second CDK contained in the second malignant tumor; and information regarding a cancer recurrence of the sample patient; selecting means for selecting one of the sample data stored in the memory whose first CDK parameter and second CDK parameter are in a prescribed range, wherein the range contains the first CDK parameter and the second CDK parameter of the cancer patient to be examined; and display means for displaying the information regarding a cancer recurrence comprised in the selected sample data.
[0008] A second aspect of the invention is A device for supporting a diagnosis of a cancer comprising: display; and controller, including a memory under control of a processor, the memory storing a plurality of sample data, each of the sample data comprising: first cyclin dependent kinase (first CDK) parameter which is capable to be acquired from an activity value and an expression level of the first CDK contained in a first malignant tumor of a sample patient who has been administered anthracyclinee anticancer drugs; second cyclin dependent kinase (second CDK) parameter which is capable to be acquired from an activity value and an expression level of the second CDK contained in the second malignant tumor; and information regarding a cancer recurrence of the sample patient, and instructions enabling the processor to carry out operations, comprising: acquiring a first CDK parameter based on an activity value and an expression level of the first CDK contained in a second malignant tumor of a cancer patient to be examined, and a second CDK parameter based on an activity value and an expression level of the second CDK contained in the second malignant tumor; selecting one of the sample data stored in the memory whose first CDK parameter and second CDK parameter are in a prescribed range, wherein the range contains the first CDK parameter and the second CDK parameter of the cancer patient to be examined; and controlling the display to display the information regarding a recurrence comprised in the selected sample data.
[0009] A third aspect of the invention is a device for predicting an effects of anthracyclinee anticancer drugs comprising: acquiring means for acquiring a first cyclin dependent kinase (first CDK) parameter which is capable to be acquired from an activity value and an expression level of the first CDK, and a second cyclin dependent kinase (second CDK) parameter which is capable to be acquired from an activity value and an expression level of the second CDK, based on an activity value and an expression level of the first CDK contained in a first malignant tumor of a cancer patient to be examined and on an activity value and an expression level of the second CDK contained in the first malignant tumor; a memory storing a plurality of sample data, each of the sample data comprising: a first CDK parameter acquired from an activity value and an expression level of the first CDK contained in a second malignant tumor of a sample patient, who has been administered anthracyclinee anticancer drugs; a second CDK parameter acquired from an activity value and an expression level of the second CDK contained in the second malignant tumor; and information regarding a cancer recurrence of the sample patient; selecting means for selecting one of the sample data stored in the memory whose first CDK parameter and second CDK parameter are in a prescribed range, wherein the range contains the first CDK parameter and the second CDK parameter of the cancer patient to be examined; predicting means for predicting an effects of anthracyclinee anticancer drugs with the cancer patient to be examined based on the information of the selected sample data; and displaying means for displaying the result of the prediction.
[0010] A fourth aspect of the invention is a device for predicting an effects of anthracyclinee anticancer drugs comprising: acquiring means for acquiring a first cyclin dependent kinase (first CDK) parameter which is capable to be acquired from an activity value and an expression level of the first CDK, and a second cyclin dependent kinase (second CDK) parameter which is capable to be acquired from an activity value and an expression level of the second CDK, based on an activity value and an expression level of the first CDK contained in a first malignant tumor of a cancer patient to be examined and on an activity value and an expression level of the second CDK contained in the first malignant tumor; a memory storing a standard value capable to divide a group of cancer patients into unless two groups different in a risk of cancer recurrence based on a first CDK parameter and a second CDK parameter, wherein the patients have not been administered anthracyclinee anticancer drugs; comparing means for comparing the first CDK parameter and the second CDK parameter of the cancer patient to be examined with the standard value stored in the memory; predicting means for predicting an effects of anthracyclinee anticancer drugs with the cancer patient to be examined based on the result of the comparing; and displaying means for displaying the result of prediction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective explanatory view of a first embodiment of a device of the present invention;
[0012] FIG. 2 is a perspective explanatory view of a tip setting member and a solid phase tip for protein in the device shown in FIG. 1 ;
[0013] FIG. 3 is a cross sectional explanatory view of the tip setting member and the solid phase tip for protein in the device shown in FIG. 1 ;
[0014] FIG. 4 is an exploded explanatory view of an upper plate and a lower plate of the solid phase tip for protein;
[0015] FIG. 5 is a perspective explanatory view of the solid phase tip for protein with the upper plate attached to the lower plate;
[0016] FIG. 6 is a cross sectional explanatory view of a column of a specimen preparation member of an activity measurement unit in the device shown in FIG. 1 ;
[0017] FIG. 7 is a perspective view of the specimen preparation member of the activity measurement unit in the device shown in FIG. 1 ;
[0018] FIG. 8 is a top view of a fluid manifold of the specimen preparation member shown in FIG. 7 ;
[0019] FIG. 9 is a cross sectional view taken along line D-D of FIG. 8 ;
[0020] FIG. 10 is a fluid circuit diagram of the specimen preparation member shown in FIG. 7 ;
[0021] FIG. 11 is a block diagram showing a partial configuration of the device (control system for controlling the device) of the present invention;
[0022] FIG. 12 is a block diagram showing a hardware configuration of a data processing unit;
[0023] FIG. 13 is a block diagram showing a hardware configuration of a body controller;
[0024] FIG. 14 is a view schematically describing a cell cycle;
[0025] FIG. 15 is a view showing an overall flow of one example of a process by the device;
[0026] FIG. 16 is a view showing an overall flow of one example of a process by the device;
[0027] FIG. 17 is a view showing a flow of one example of a preparation process of the expression level measurement specimen;
[0028] FIG. 18 is a view showing a flow of one example of a preparation process of the activity measurement specimen;
[0029] FIG. 19 is a view showing an overall flow of one example of an analyzing process by the device;
[0030] FIG. 20 is a view showing an example of a display screen;
[0031] FIG. 21 is a schematic explanatory view of a graph shown on a distribution diagram display region in the display screen of a diagnosis support device of a second embodiment;
[0032] FIG. 22 is a schematic explanatory view of a graph shown on a distribution diagram display region in the display screen of a diagnosis support device of a third embodiment;
[0033] FIG. 23 is a schematic explanatory view of a graph shown on a distribution diagram display region in the display screen of a diagnosis support device of a fourth embodiment;
[0034] FIG. 24 is a graph showing cancer patients not treated with anticancer drug in three groups of different recurrence risks;
[0035] FIG. 25 is a view showing an example of the display screen;
[0036] FIG. 26 is an explanatory view showing the usage procedures of the sample and the like in the device; and
[0037] FIG. 27 is a view showing an example of the display screen.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] A device for supporting a diagnosis of a cancer of the present invention, a device for predicting effectiveness of the anthracycline anticancer drugs of the present invention, and a method of predicting the effectiveness of the anthracycline anticancer drugs in a cancer patient to be examined of the present invention will be described in detail below with reference to the accompanying drawings.
[0039] Malignant tumors are tumors that invade or metastasize to other tissues, and enlarge at various sites of the body thereby threatening the life. The malignant tumor includes cancer or malignant tumor originating from epithelial tissue, and sarcoma or malignant tumor originating from non-epithelial tissue. Specifically, the malignant tumor includes malignant tumors forming at positions such as breast, lung, liver, stomach, large intestine, pancreas, uterus, testis, ovaria, thyroid, accessory thyroid, lymphography, and the like. The malignant tumor can be obtained from cancer patients having breast cancer, lung cancer, liver cancer, gastric cancer, large intestine cancer, pancreas cancer, prostate cancer, and the like.
[0040] [1] CDK Serving as Parameter in Cancer
[0041] The cyclin-dependent kinase (CDK) accurately reflects and represents the state of malignant tumor in a patient with cancer. The CDK shows similar profile for cancer patients having malignant tumors of a similar state. Thus, the likeliness of the cancer to recur, the effectiveness of the anticancer drug, and the like can be evaluated based on a first parameter acquired from an activity value and an expression level of a first CDK in the malignant tumor and a second parameter acquired from an activity value and an expression level of a second CDK in the malignant tumor.
[0042] The recurrence refers to a case where the same malignant tumor reappears in the remaining organs after an organ is partially removed to extirpate the malignant tumor, and a case where the tumor cell is separated from a primary tumor and conveyed to a remote tissue (remote organ), and independently grows thereat (metastasize and recur). Generally, “likely to recur” refers to a case where there is a possibility the cancer will recur within five years after the extirpative surgery. Since the death rate of the patients recognized with recurrence within five years is high, predicting the recurrence within five years after the extirpative surgery has clinical meaning. In stage classification, stage III has a recurrence rate of 50%, and recurrence is likely to occur compared to stage II (recurrence rate of 20%).
[0043] In the present specification, the cyclin-dependent kinase is a collective term of a phosphorylated enzyme group activated by being bounded to cyclin. The cyclin-dependent kinase functions in a specific time of the cell cycle depending on the type thereof. In the present specification, the CDK inhibitor is a collective term of a factor group that bonds with the cyclin CDK complex and inhibits the activity of the cyclin CDK complex.
[0044] The cell cycle is a cycle that the cell starts to grow and return to the starting point as two daughter cells after events of DNA replication, distribution of chromosomes, nuclear division, cytoplasmic division, and the like. The cell cycle is divided into four periods of G 1 period, S period, G 2 period, and M period, as shown in FIG. 14 . The S period is the replication period of DNA, and the M period is the division period. The G 1 period is a preparation period for the cell to enter the S period between the completion of mitotic division and the start of DNA synthesis. After passing a critical point (point R in animal cell) in the G 1 period, the cell cycle starts, and normally completes one cycle without stopping in the middle. The G 2 period is a preparation period for the cell to enter the M period between the termination of DNA synthesis and the start of mitotic division. Main check points of the cell cycle is immediately before entering the S period from the G 1 period (G 1 check point), and the transition period (G 2 /M check point) from the G 2 period to mitotic division. In particular, the G 1 check point is important as it triggers the start of the S period. This is because, after passing a certain point of the G 1 period, the cell advances the cell cycle as S period □ G 2 period □ M period □ G 1 period without stopping the growth even if a growth signal is not provided. The cell that has stopped growing enters a rest period (G 0 ) having DNA content of the G 1 period, and the state deviates from the cell cycle. Due to growth induction, the cell can advance to the S period after a time slightly longer than the G 1 period in the cell cycle.
[0045] The CDK is not particularly limited, and may be CDK1, CDK2, CDK4, CDK6, and the like. The CDK also includes CDK belonging to cyclin A-dependent kinase, CDK belonging to cyclin B-dependent kinase, CDK belonging to cyclin D-dependent kinase, CDK belonging to cyclin E-dependent kinase, and the like. The cyclin A-dependent kinase is not particularly limited as long as it is CDK that indicates activity by being bound to cyclin A, but includes CDK1, CDK2, and the like. The cyclin B-dependent kinase is not particularly limited as long as it is CDK that indicates activity by being bound to cyclin B, but includes CDK1 and the like. The cyclin D-dependent kinase is not particularly limited as long as it is CDK that indicates activity by being bound to cyclin D, but includes CDK4, CDK6, and the like. The cyclin E-dependent kinase is not particularly limited as long as it is CDK that indicates activity by being bound to cyclin E, but includes CDK2 and the like.
[0046] Such CDK activates a predetermined period of the cell cycle as shown in table 1 by being a cyclin-CDK complex (hereinafter also referred to as “active CDK”) bound to the corresponding cyclin, as shown in table 1. For instance, CDK1 becomes active by binding to cyclin A or B, CDK2 becomes active by binding to cyclin A or E, and CDK4 and CDK6 become active by binding to cyclin D1, cyclin D2, or cyclin D3. The CDK activity sometimes has the activity inhibited by the CDK inhibitor as shown in table 1. For instance, p21 inhibits CDK1 and CDK2, p27 inhibits CDK2, CDK4, and CDK6, and p16 inhibits CDK4 and CDK6.
[0000]
TABLE 1
Binding
Binding
CDK
CDK
cyclin
inhibitor
Operating period of active CDK
CDK4
Cyclin D1
p27, p16
G 1 period
CDK6
Cyclin D2
Cyclin D3
CDK2
Cyclin E
p27
G 1 period → S period transition
CDK2
Cyclin A
p21, p27
S period active
CDK1
Cyclin A
p21
G 2 period → M period transition
Cyclin B
Cyclin A-
Cyclin A
p21, p27
CDK1: G 2 period → M period
dependent
CDK2: middle period of S period
kinase
Cyclin B-
Cyclin B
p21
CDK1: G 2 period → M period
dependent
kinase
Cyclin D-
Cyclin D
p27, p16
CDK4, CDK6: G 1 period
dependent
kinase
[0047] Among the CDKs, the activity value and the expression level of the first CDK are measured and the first parameter is acquired from the activity value and the expression level, and the activity value and the expression level of the second CDK are measured and the second parameter is acquired from the activity value and the expression level. The first parameter is a ratio of the expression level and the activity value of the first CDK, specifically, the specific activity represented with the following equation (I):
[0000] Specific activity of first CDK=activity value of first CDK/expression level of first CDK (I)
[0048] The second parameter is a ratio of the expression level and the activity value of the second CDK, specifically, the CDK specific activity represented with the following equation (II):
[0000] Specific activity of second CDK=activity value of second CDK/expression level of second CDK (II)
[0049] The CDK activity value refers to the level (unit is expressed as U (unit)) of the kinase activity calculated from the amount of substrate that binds with a specific cyclin, and phosphorylates the cyclin. The substrate to which the CDK phosphorylates includes histon H 1 for active CDK1 and active CDK2, and Rb (retinoblastoma protein) for active CDK4 and active CDK6). The CDK activity value can be measured with a conventional CDK activity measurement method. Specifically, there may be a method of preparing a specimen containing the active CDK from the cell dissolved solution of the measurement specimen, retrieving 32 P into the substrate protein by using the relevant specimen and the 32 P labeled ATP (γ-[ 32 P]-ATP), measuring the labeled quantity of the 32 P labeled phosphorylated substrate, and determining the quantity based on the standard curve created with a standard product. A method that does not use label of the radioactive substance includes a method disclosed in Japanese Laid-Open Patent Publication No. 2002-335997. This method is a method of preparing a specimen containing the target active CDK from the cell solubilizing solution of the measurement specimen, reacting adenosine 5′-O-(3-thiotriphosphate) (ATP-γS) and the substrate protein, introducing monothiophosphate group to serine residue or threonine residue of the substrate protein, bonding fluorescent labeled substance or labeled enzyme to the sulfur atom of the introduced monothiophosphate group to label the substrate protein, measuring the labeled quantity (fluorescence quantity when fluorescent labeled substance is used) based on the labeled thiophosphate group, and determining the quantity based on the standard curve created with the standard product.
[0050] The specimen provided for activity measurement is prepared by specifically obtaining the target CDK from the solubilizing solution of the tissue containing the malignant tumor to be measured. In this case, the specimen may be prepared using an anti-CDK antibody specific to the target CDK. The specimen may be prepared using an anti-cyclin antibody in the case of activity measurement of a specific cyclin-dependent kinase (e.g., cyclin A-dependent kinase, cyclin B-dependent kinase, cyclin E-dependent kinase). In either case, the specimen contains CDK other than the active CDK. For instance, the specimen contains a complex in which the CKD inhibitor is bound to the cyclin CDK complex. When the anti-CDK antibody is used, the specimen contains CDK single body, complex of CDK and cyclin and/or CDK inhibitor, complex of CDK and other compound, and the like. Therefore, the activity value is measured as a unit (U) calculated from the amount of phosphorylated substrate under a state that active type, inactive type, and various competitive reactions coexist.
[0051] The CDK expression level is the target CDK level (unit corresponding to number of molecules) measured from the cell solubilizing solution, and is measured with a conventionally known method of measuring the target protein quantity from the protein mixture. For instance, ELISA method, western blot method, and the like may be used, or measurement may be carried out with a method disclosed in Japanese Laid-Open Patent Publication No. 2003-130871. The target protein (CDK) is captured using a specific antibody. For instance, all the CDK1 existing within the cell (including CDK single body, complex of CDK and cyclin and/or CDK inhibitor, complex of CDK and other compound) can be captured using the anti-CDK1 antibody.
[0052] Therefore, the specific activity calculated from the equations (I) and (II) corresponds to the proportion of the CDK indicating activity of the CDK existing in the cell, and is the CDK activity level based on the growth state of the malignant tumor cell, which is the target of determination. The CDK specific activity thus obtained does not depend on the measurement specimen preparation method. In particular, the measurement specimen (cell solubilizing solution) prepared from the biopsy material is likely to be influenced by the size of non-cellular tissues such as extracellular matrix contained in the actually collected tissue. Therefore, there is a large meaning to use the specific activity in which such influence is eliminated, and the correlation with the clinical characteristics is high compared to the simple activity value.
[0053] Which CDK activity is superior can be known from the specific activity of the first CDK and the specific activity of the second CDK, whereby the extent of the cell proportion in any period of the cell cycle can be known, or the cell proportion of which period is superior can be known.
[0054] The type of CDK for measuring the specific activity is not particularly limited, and may be appropriately selected. Generally, since the cancer cells actively grow deviating from the normal growth control, cell proportion in the S period and the G 2 period is considered to be large, and the cells are considered to become cancerous in such case. The progression of such cancer can be fast, and thus such cancer can be malignant. Furthermore, heteroploidy is considered to occur when an abnormal M period has elapsed or the cell has advanced to the G 1 period without going through the M period and then entered to the S period, and thus, the cell is considered to be malignant when the cell proportion in the M period is small. Therefore, the CDK1 is used as the first CDK and the CDK2 is used as the second CDK, classification to groups is carried out according to the magnitude of the CDK1 specific activity, wherein the CDK2 specific activity value takes a value reflecting the cell ratio in the S period of the groups having a similar CDK1 specific activity. When cells in the S period are in great numbers, the tissue where the cells are configuring cells can be determined as clinically malignant, that is, as a malignant cancer that is likely to metastasize and has poor prognosis.
[0055] Therefore, information useful in diagnosing the cancer patient to be examined can be provided by obtaining the first parameter in the malignant tumor of the cancer patient to be examined, such as the specific activity of the first CDK, and the second parameter or the specific activity of the second CDK, and providing information having the first parameter and the second parameter within a sample data extraction range defined based on the first parameter and the second parameter of the malignant tumor of the cancer patient to be examined and being related to the recurrence of the cancer patient administered with the anthracycline anticancer drug.
[0056] Information useful in predicting the effectiveness of the anthracycline anticancer drugs in the cancer patient to be examined, in selecting the treatment method for the cancer patient to be examined, and the like can be provided by obtaining the first parameter in the malignant tumor of the cancer patient to be examined, such as the specific activity of the first CDK, and the second parameter or the specific activity of the second CDK, and providing information having the first parameter and the second parameter within a sample data extraction range defined based on the first parameter and the second parameter of the malignant tumor of the cancer patient to be examined and being related to the recurrence, after the malignant tumor is extirpated, of the cancer patient administered with the anthracycline anticancer drug.
[0057] [2] Diagnosis Support Device
[0058] The diagnosis support device according to one embodiment (first embodiment) of the present invention will be described below. The diagnosis support device according to the present embodiment uses the specific activity of the first CDL as the first parameter and the specific activity of the second CDK as the second parameter.
[0059] Specifically, the diagnosis support device according to the first embodiment acquires the expression levels and the activity values of the CDK1 and the CDK2 of the malignant tumor collected from the cancer patient to be examined. The CDK1 specific activity and the CKD2 specific activity are calculated from the expression levels and the activity values of the acquired CDK1 and CDK2. A sample data extraction range is determined based on the calculated CDK1 specific activity and CDK2 specific activity. The device of the first embodiment stores data including sample data in which the first parameter and the second parameter of the malignant tumor collected from the cancer patient administered with the anthracycline anticancer drugs are corresponded to information related to the recurrence of the cancer patient after the malignant tumor is extirpated. The sample data of the patient is extracted from the data stored in advance. Screen information for displaying a screen including the information related to the recurrence contained in the extracted sample data and the information on the cancer patient to be examined on a display device is generated, and the generated screen is allowed to display.
[0060] The data stored in advance in the device of the first embodiment contains the sample data. The sample data includes information obtained from a plurality of cancer patients administered with the anthracycline anticancer drugs. Specifically, the first parameter and the second parameter of the malignant tumor collected from the cancer patient are included. Furthermore, information related to the recurrence of the cancer patient after the malignant tumor is extirpated is also included. The information related to the recurrence after the malignant tumor is extirpated specifically includes presence of recurrence of the cancer patient, a number of days from extirpation of the malignant tumor to recurrence (if recurrence has not occurred, a number of days elapsed from the extirpation).
[0061] The screen displayed by the display device on the device of the first embodiment includes information related to recurrence contained in the extracted sample data and the information on the cancer patient to be examined. The information related to the recurrence contained in the extracted sample data specifically includes information on the presence of recurrence of the relevant patient. Furthermore, the recurrence rate calculated based on the information on the presence of the recurrence is also included therein. The information on the cancer patient to be examined includes ID number, age, and the like of the cancer patient to be examined. Furthermore, the CDK1 specific activity and the CDK2 specific activity of the malignant tumor of the cancer patient to be examined are also included therein.
[0062] FIG. 1 is a perspective explanatory view of the first embodiment of the device of the present invention. The diagnosis support device according to the first embodiment is configured by a measuring device A and a solubilizing device B. The measuring device A is configured by a measurement unit 501 and a data processing unit 12 . The measuring unit 501 measures the activity value and the expression level of the CDK1 and the activity value and the expression level of the CDK2, and is mainly configured by a detecting member 4 arranged at the front portion of a device body 20 ; a tip setting member 1 ; first reagent setting member 5 and second reagent setting member 6 ; an activity measurement unit 2 arranged at a back portion of the device body 20 ; a waste bath 7 for accommodating waste liquid and a pipette washing bath 8 for washing pipette; a dispensing mechanism member 3 arranged on the upper side of the device body 20 , for moving the pipette in three directions (X direction, Y direction, and Z direction); and a fluid member 9 and a body controller 10 arranged at the back part of the device body 20 . The data processing unit 12 is communicably connected to the body controller 10 . A pure water tank 13 , a washing liquid tank 14 , a waste liquid tank 15 , and a pneumatic source 11 are arranged in the measuring device A. The pure water tank 13 stores pure water for washing a flow channel at the end of measurement and is connected to the fluid member 9 with a conduit 21 ; the washing liquid tank 14 stores washing liquid for washing the pipette and is connected to the pipette washing bath 8 with a conduit 22 ; and the waste liquid tank 15 for accommodating the waste liquid is connected to the waste bath 7 with a conduit 23 . The solubilizing device B for obtaining a sample that can be processed in the measuring device A from a biological specimen is arranged next to the measuring A in the diagnosis support device according to the first embodiment.
[0063] The solubilizing device B and the measuring device A will be described in order below.
[Solubilizing Device]
[0064] The solubilizing device B prepares a liquid sample that can be processed in the measuring device A from the biological specimen of the tissue and the like extirpated from the patient prior to the process by the measuring device A, and is mainly configured by a housing 30 , an operating member 31 arranged on the upper side at the front surface of the housing 30 , a driving member 32 including a pair of pestles 34 for pressing and grinding the biological specimen, and a sample setting member 33 to be set with an eppen tube 35 accommodating the biological specimen.
[0065] The driving member 32 moves the pestles 34 in the up and down direction and provides rotational movement thereto, so that the biological specimen injected into the eppen tube 35 is pressed and grinded. A controller (not shown) for controlling the operation of the driving member 32 is arranged in the housing 30 .
[0066] An operation button 31 a , an operation lamp 31 b , and a display part 31 c for displaying the state of the device and error message are arranged on the operating member 31 . A cooling means (not shown) is arranged in the sample setting member 33 to maintain the biological specimen in the eppen tube (product name) set in a concave area of the upper surface of the sample setting member 33 at a constant temperature.
[0067] The supernatant solution of the biological specimen solubilized by the solubilizing device B and subjected to centrifugal process by a centrifugal machine (not shown) is collected to a predetermined sample container and set in the first reagent setting member 5 of the measuring device A.
[First Reagent Setting Member]
[0068] A cooling means (not shown) is arranged in the first reagent setting member 5 , similar to the sample setting member 33 , to maintain the sample, the CDK1 antigen (calibration 1), the CDK2 antigen (calibration 2), the fluorescent labeled CDK1 antibody, the fluorescent labeled CDK2 antibody and the like in the container such as screw cap set in the concave area of the upper surface of the first reagent setting member 5 at a constant temperature. In the first embodiment, a total of 20 concave areas are formed in a matrix of five by four, so that a maximum of 20 containers such as screw cap can be set.
[Second Reagent Setting Member]
[0069] The second reagent setting member 6 is arranged next to the first reagent setting member 5 . A plurality of concave areas is formed in the second reagent setting member 6 , similar to the first reagent setting member 5 , and the eppen tube (product name) and the containers such as screw cap with buffer, substrate solution, and fluorescent enhancement reagent are set in these concave areas.
[0070] Prior to the process by the measuring device A, a solid phase tip for protein is set in the tip setting member 1 , and a column is set in the activity measurement unit 2 .
[Tip Setting Member]
[0071] The tip setting member 1 is made up of aluminum blocks, wherein a concave part 102 for mounting the solid phase tip for protein 101 is formed at the upper surface and three aspiration ports 103 are formed at the bottom part, as shown in FIGS. 2 and 3 . More specifically, the tip setting member 1 includes a first concave part 102 of rectangular shape at the upper surface, and three second concave parts 104 also of rectangular shape at the bottom part of the first concave part 102 . The second concave parts 104 are independent from each other by a partition wall 105 so as to be in a non-communicating state when the solid phase tip for protein 101 is mounted on the tip setting member 1 . A rubber elastic gasket 106 of rectangular frame shape is arranged at the peripheral edge of the second concave part 104 at the bottom surface of the first concave part 102 .
[0072] The second concave part 104 includes a cross-shaped groove 107 at the bottom part and the aspiration port 103 at the center of the bottom part, wherein the groove bottom of the groove 107 is inclined so as to become deeper towards the center from the peripheral edge of the second concave part 104 . The aspiration port 103 communicates with a nipple 108 arranged to connect to an external aspiration pneumatic source 11 . A tube 109 having one end connected to the aspiration pneumatic source 11 side has the other end connected to the nipple 108 . An open/close valve 110 is arranged in the tube 109 .
[0073] The solid phase tip for protein 101 to be hereinafter described in detail is mounted horizontally at the bottom surface of the first concave part 102 by way of a gasket 106 . The aspiration pump is activated after the protein containing specimen solution is injected or dropped into each well of the solid phase tip for protein 101 .
[0074] The solid phase tip for protein 101 is then air tightly attracted to the bottom surface of the first concave part 102 by way of the gasket 106 , and the specimen solution in each well is aspirated through the porous film, to be hereinafter described, whereby the protein to be measured is solid phase formed on the porous film. In FIGS. 2 and 3 , 130 is a pressing mechanism for pressing and fixing the solid phase tip for protein 101 to the bottom surface of the first concave part 102 . The pressing mechanism 130 is sled in a direction of the arrow in the figure after the solid phase tip for protein 101 is mounted on the first concave part 102 , so that the upper part thereof presses the upper surface of the solid phase tip for protein 101 and fixes the same to the first concave part 102 .
[0075] As shown in FIGS. 4 and 5 , the solid phase tip for protein 101 is configured by a porous film 111 and a filter paper 112 , and upper plate 113 and lower plate 114 for sandwiching the porous film 111 and the filter paper 112 . The solid phase tip for protein 101 has a function of contacting the antibody solution containing antibody of cyclin-dependent kinase and the biological specimen (sample).
[0076] As shown in FIGS. 4 and 5 , the upper plate 113 is configured by three plates being independent from each other, that is, a first upper plate 113 a , a second upper plate 113 b , and a third upper plate 113 c . Each upper plate has a rectangular plate shape, wherein the first upper plate 113 a and the second upper plate 113 b are both formed with twelve oval through holes 115 arrayed in a matrix form of four by three, and the third upper plate 113 c is formed with sixteen oval through holes 115 arrayed in a matrix form of four by four. Each upper plate includes a region, which is independent from each other for specimen processing, formed with a plurality of through holes. A groove 116 is formed along a short side at the bottom surface of each upper plate.
[0077] A total of forty oval through holes 117 arrayed in a matrix form is formed in the lower plate 114 having a rectangular plate shape at positions corresponding to each through hole 115 of the upper plates 113 a , 113 b , 113 c . The through holes 117 have the same shape and cross sectional area as the through holes 115 . The lower plate 114 has a region formed with a plurality of through holes corresponding to each region of the upper plates 113 a , 113 b , 113 c.
[0078] A rib-shaped convex part 118 that goes around the periphery of the forty through holes 117 once, and a partition wall 119 for partitioning the through holes 117 to three regions in correspondence to each region of the upper plate 113 a , 113 b , 113 c are formed on the upper surface of the lower plate 114 . Three rectangular porous film installing regions are partitioned on the inner side by the convex part 118 and the partition wall 119 . The upper plate 113 and the lower plate 114 may be made of vinyl chloride resin and the like.
[0079] As shown in FIGS. 2 to 5 , a stacked body including the porous film 111 and the filter paper (filter) 112 is mounted on the porous film installing region of the lower plate 114 , and the grooves 116 of each upper plate 113 a , 113 b , 113 c are sequentially fitted to the corresponding convex part 118 of the lower plate 114 , so that the upper plates 113 a , 113 b , 113 c are attached to the lower plate 114 thereby forming the solid phase tip for protein 101 . Each through hole 115 and each through hole 117 then become coaxial to each other.
[0080] The solid phase tip for protein described above has the upper plate divided into three regions, so that three regions can be aspirated independently, but the number of upper plates may be two, or four or more, and is not particularly limited in the present invention. The number of upper plates is appropriately selected in view of the number of measurement items and the number of samples.
[Activity Measurement Specimen Preparation Unit]
[0081] As shown in FIGS. 6 to 10 , the activity measurement specimen preparation unit 2 includes a plurality of specimen preparation members 211 each including a column 201 and a fluid manifold 213 , and is used to measure the activity value of the CDK.
[0082] The column 201 shown in FIG. 6 is made of a cylindrical body made of vinyl chloride resin, and includes therein a carrier holding member 202 for holding a carrier 206 used to isolate the target substance in the liquid specimen, and a liquid storage member 204 for receiving and storing the liquid specimen to introduce the liquid specimen to the carrier holding member 202 . The column 201 has an opening 205 through which the liquid sample can be externally injected or from which the liquid specimen can be collected from the outside at the upper part of the liquid storage member 204 , and includes a connection flow channel 203 for introducing the liquid specimen to the fluid manifold 213 to the lower part of the carrier holding member 202 and receiving the liquid specimen from the fluid manifold 213 . The column 201 configures a means for contacting the substrate solution containing a predetermined substrate and the biological specimen (sample).
[0083] The carrier 206 is made of monolithic silica gel of circular cylinder shape, wherein the monolithic silica gel has a configuration in which the three-dimensional network frame work and the clearance thereof are integrated, unlike to the particle carrier. The predetermined CDK antibody is immobilized to the monolithic silica gel. The carrier 206 is inserted to the carrier holding member 202 from the lower opening of the column 201 , and is elastically pushed and supported by a fixing pipe 208 by way of an O-ring 207 . The fixing pipe 208 is press-fit from the lower opening of the column 201 , wherein the fixing pipe 208 and the hole of the O-ring 207 form the connection flow channel 203 .
[0084] A mounting flange 209 for mounting and fixing the column 201 to the specimen preparation member 211 is formed at the lower end of the column 201 . The flange 209 is an oval flange formed by cutting out both sides of a disc shaped flange having a diameter D in parallel so as to have a width W (W<D).
[0085] FIG. 7 is a perspective explanatory view of the specimen preparation member of the activity measurement unit in the device of FIG. 1 . As shown in FIG. 7 , the specimen preparation member 211 includes an L-shaped supporting plate 212 , and the fluid manifold 213 , a syringe pump 214 , and a stepping motor with reducer 215 are fixed on the supporting plate 212 .
[0086] A screw shaft 216 is connected to the output shaft of the stepping motor 215 . A drive arm 217 to be screwed to the screw shaft 216 is connected to the distal end of a piston 218 of the syringe pump 214 . The piston 218 moves up and down when the screw shaft 216 is rotated by the stepping motor 215 . The syringe pump 214 and the fluid manifold 213 are connected to a liquid feeding tube 250 by way of connectors 219 , 220 . The syringe pump 214 is connected to a chamber 234 (see FIG. 10 ) accommodating fluid (washing liquid) for filling the flow channel by a liquid feeding tube 220 b by way of a connector 220 a.
[0087] As shown in FIGS. 8 and 9 , the fluid manifold 213 includes a column connecting part 221 to which the lower opening of the column 201 is connected.
[0088] The fluid manifold 213 includes a flow channel 223 therein, and has an electromagnetic valve 225 for opening/closing the flow channel 223 and the column connecting part 221 on the lower surface. The fluid manifold 213 has a connector connection screw hole 226 for connecting a connector 220 on the side surface, which screw hole 226 is connected to the flow channel 223 .
[0089] FIG. 10 is a fluid circuit diagram of the specimen preparation member shown in FIG. 7 . FIG. 10 shows a state in which the syringe pump 214 is connected to the fluid manifold 213 by way of the connector 220 . A chamber 234 is connected to the syringe pump 214 by way of the electromagnetic valve 233 , and positive pressure is applied to the chamber 234 from a positive pressure source 235 .
[0090] A method of mounting the column 201 to the fluid manifold 213 will be now described.
[0091] As shown in FIGS. 8 to 10 , a column mounting concave part 227 for receiving the lower end of the column 201 is formed on the upper surface of the fluid manifold 213 , the center of the bottom part of the concave part 227 passes through the column connecting part 221 , and an O-ring 228 is attached to the circumference of the bottom part. Two pressing plates 229 , 230 having a cross section of L-shape are fixed in parallel on the upper surface of the fluid manifold 213 at an interval wider than the width W and narrower than D with the column mounting concave part 227 as the center.
[0092] In order to prevent sample or reagent that has passed the carrier 206 inside the column 201 fixed to the fluid manifold 213 from contacting fluid (washing liquid) that fills the flow channel 223 inside the fluid manifold 213 and being diluted, the electromagnetic valve 225 is opened (electromagnetic valve 233 is closed) before the column 201 is fixed to the column mounting concave part 227 and the syringe pump 214 is aspiration operated only by about 16 μL. The liquid level of the column connecting part 221 thereby lowers and an air gap forms.
[0093] Subsequently, the column 201 is mounted to column mounting concave part 227 so that the flange 209 passes between the pressing plates 229 , 230 , and then rotated clockwise or counterclockwise by 90 degrees. The portion of the diameter D of the flange 209 engages the pressing plates 229 , 230 , and the flange 209 is fixed by the pressing plates 229 , 230 due to the elasticity of the O-ring 228 . When removing the column 201 , the column 201 is rotated either to the left or the right by 90 degrees while being pushed.
[0094] When the column 201 is mounted to fluid manifold 213 of the specimen preparation unit 211 , the concave part 227 of the fluid manifold 213 is filled with manually or automatically dispensed fluid in order to prevent air bubbles from mixing, but the fluid flows out from increase in volume when the distal end of the column 201 is inserted to the concave part 227 . An overflow liquid storage concave part 231 is arranged at the periphery of the column mounting concave part 227 in order to prevent the fluid from flowing out to the periphery, and an overflow liquid discharging concave part 232 for aspirating and discharging the overflow liquid by pipette is arranged at one part of the overflow liquid storage concave part 231 .
[0095] Various samples and reagents are injected or aspirated to or from a predetermined location by the dispensing mechanism member 3 equipped with the pipette.
[0096] The operation of the upper opening 205 of the column 201 in a case where the sample or the reagent is injected will be now described. The electromagnetic valve 225 is first opened (electromagnetic valve 233 is closed), and the syringe pump performs the aspirating operation when the sample or the reagent is injected to the opening 205 . The air gap and the sample or the reagent are then passed through the electromagnetic valve 225 , and then aspirated to the syringe pump side. The syringe pump then performs ejecting operation. The sample or the reagent is then passed through the electromagnetic valve 225 , and sent to the column 201 .
[Dispensing Mechanism Member]
[0097] As shown in FIG. 1 , the dispensing mechanism member 3 includes a frame 352 for moving the pipette in the X direction, a frame 353 for moving the pipette in the Y direction, and a plate 354 for moving the pipette in the Z direction.
[0098] The frame 352 includes a screw shaft 355 for moving the plate 354 in the direction of the arrow X, a guide bar 356 for supporting and slidably moving the plate 354 , and a stepping motor 357 for rotating the screw shaft 355 .
[0099] The frame 353 includes a screw shaft 358 for moving the plate 352 in the direction of the arrow Y, a guide bar 359 for supporting and slidably moving the frame 352 , and a stepping motor 361 for rotating the screw shaft 358 .
[0100] The plate 354 includes a screw shaft 367 for moving an arm 368 supporting the pipette 362 in the direction of the arrow Z, a guide bar for supporting and slidably moving the arm 368 , and a stepping motor 370 for rotating the screw shaft 367 .
[0101] In the first embodiment, since the dispensing mechanism member 3 is equipped with a pair of pipettes 362 , reagent and the like can be simultaneously injected to two sample containers and content can be simultaneously aspirated from two sample containers, whereby the measuring process can be efficiently performed.
[Fluid Member]
[0102] As shown in FIG. 1 , a fluid member 9 , connected to the pipette washing bath 8 for washing the pipette 362 and each specimen preparation member 211 , for operating the fluid is arranged at the rear part of the device body 20 . As shown in FIG. 10 , the fluid member 9 includes an electromagnetic valve 225 of each specimen preparation member 211 , an electromagnetic valve 233 for controlling the fluid when filling the liquid from the washing liquid chamber to the syringe 214 , an electromagnetic valve for controlling fluid when aspirating and ejecting the liquid with the pipette 362 , an electromagnetic valve for controlling the fluid when aspirating the liquid wasted from the pipette 362 in the waste bath 7 , and an electromagnetic valve for controlling the fluid when washing the pipette 362 in the pipette washing bath 8 .
[Detecting Member]
[0103] The detecting member 4 is provided to measure the fluorescence quantity based on the bound fluorescent labeled substance reflecting the protein quantity and the fluorescence quantity based on the fluorescent labeled substance reflecting the amount of phosphate group captured at the porous film 111 of the solid phase tip for protein 101 , wherein excitation light is irradiated on the solid phase tip for protein 101 , the generated fluorescence is detected, and the electric signal having a magnitude corresponding to the intensity of the detected fluorescence is output to the body controller 10 . A generally used detecting member configured by light source unit, illumination system, and light receiving system can be appropriately adopted for the detecting member 4 .
[Data Processing Unit]
[0104] FIG. 11 is a block diagram showing a partial configuration (control system for controlling the device) of the device of the first embodiment. As shown in FIG. 1 , the data processing unit 12 or the personal computer includes a control member 77 , an input member 78 , and a display member 79 .
[0105] The control member 77 has a function of transmitting an operation start signal of the device to the body controller 10 to be hereinafter described. When a command to start operation is transmitted from the control member 77 , the body controller 10 outputs a drive signal for driving the stepping motor 215 of each specimen preparation member 211 , a drive signal for adjusting the temperature of the first reagent setting member 5 , a drive signal for driving the stepping motors 357 , 361 , 370 , and a drive signal for driving the electromagnetic valve in the fluid member 9 . The control member 77 further has a function for analyzing the detection result obtained in the detecting member 4 .
[0106] The detection result obtained in the detecting member 4 is transmitted to the body controller 10 . The body controller 10 transmits the detection result obtained in the detecting member 4 to the control member 77 .
[0107] The display member 79 is arranged to display result of analysis and the like obtained in the control member 77 .
[0108] The configuration of the personal computer used as the data processing unit 12 will be now described in detail. As shown in FIG. 12 , the control member 77 is mainly configured by a CPU 91 a , a ROM 91 b , a RAM 91 c , an input/output interface 91 d , an image output interface 91 e , a communication interface 91 f , and a hard disc 91 g . The CPU 91 a , the ROM 91 b , the RAM 91 c , the input/output interface 91 d , the image output interface 91 e , the communication interface 91 f , and the hard disc 91 g are connected with an electric signal line (bus) so as to communicate electrical signals.
[0109] The CPU 91 a can execute computer programs stored in the ROM 91 b and the computer programs loaded in the RAM 91 c . The personal computer can serve as the data processing unit 12 when the CPU 91 a executes the application program 91 h , as hereinafter described, and executes the operations to be hereinafter described.
[0110] The ROM 91 b is configured by mask ROM, PROM, EPROM, EEPROM, and the like, and is recorded with computer programs to be executed by the CPU 91 a , data used for the same, and the like.
[0111] The RAM 91 c is configured by SRAM, DRAM, and the like. The RAM 91 c is used to read out the computer programs recorded on the ROM 91 b and the hard disc 91 g . The RAM 91 c is used as a work region of the CPU 91 a when executing these computer programs.
[0112] Various computer programs to be executed by the CPU 91 a such as operating system and application program, as well as data used in executing the computer program are installed in the hard disc 91 g . A predetermined application program 91 h is also installed in the hard disc 91 g . The predetermined application program is a program for acquiring the expression levels and the activity values of the CDK 1 and the CDK 2 from the malignant tumor of the cancer patient to be examined, calculating the CDK 1 specific activity and the CDK 2 specific activity from the acquired expression levels and the activity values of the CDK 1 and the CDK 2, determining a sample data extraction range based on the calculated CDK 1 specific activity and CDK 2 specific activity, extracting sample data having the CDK 1 specific activity and the CDK 2 specific activity within the determined range and of the cancer patient administered with anthracycline anticancer drug (such cancer patient is hereinafter referred to as “relevant patient”), calculating the recurrence rate based on the information related to recurrence contained in the extracted sample data, generating a screen including the calculated recurrence rate and the information on the cancer patient to be examined based on the presence of recurrence contained in the information related to the recurrence and the information related to the recurrence, and displaying the generated screen on the display member 79 .
[0113] In order to acquire the expression level and the activity value, the hard disc 91 g includes a first database 91 i for storing a standard curve or conversion data for converting fluorescence intensity to expression level or activity value. The standard curve may be obtained for every measurement of the expression level or the activity value. The first database 91 i of the hard disc 91 g stores data to use in the calculation for determining the sample data extraction range, data of default value of the sample data extraction range, and data of a set value of the sample data extraction range input and used in the past. The first database 91 i of the hard disc 91 g also stores information related to recurrence.
[0114] The hard disc 91 g includes a second database 91 j for storing sample data in which the measurement value such as the activity value and the expression level of great number of cancer patients and the clinical information such as presence/absence of recurrence, a number of days from the extirpation of the malignant tumor to the recurrence occurred (if recurrence did not occur, a number of days elapsed after extirpation), information related to postsurgical treatment such as administration of anthracycline anticancer drug and hormone treatment, information related to living body and the like of the relevant cancer patient are corresponded to each other.
[0115] Operating system providing graphical user interface environment such as Windows (registered trademark) manufactured and sold by US Microsoft Co. is installed in the hard disc 91 g . In the following description, the application program 91 h according to the first embodiment is assumed to operate on the operating system.
[0116] The input/output interface 91 d is configured by serial interface such as USB, IEEE1394, RS-232C; parallel interface such as SCSI, IDE, IEEE1284; analog interface such as D/A converter, A/D converter, and the like. The input member 78 such as keyboard and mouse is connected to the input/output interface 91 d , so that the user can input data to the data processing unit 12 by using the input member 78 .
[0117] The communication interface 91 f is, for example, Ethernet (registered trademark) interface. The data processing unit 12 transmits and receives data with the body controller 10 by using a predetermined communication protocol by means of the communication interface 91 f.
[0118] The image output interface 91 e is connected to the display member 79 configured by LCD, CRT, or the like, and is configured to output an image signal corresponding to the image data provided from the CPU 91 a to the display member 79 . The display member 79 displays the image (screen) according to the input image signal.
[Body Controller]
[0119] The body controller 10 , connected to each specimen preparation member 211 , the detecting member 4 , the stepping motors 357 , 361 , 370 , the fluid member 9 and the like, for controlling the same is arranged at a back part of the device body 20 .
[0120] As shown in FIG. 13 , the body controller 10 includes a CPU 301 a , a ROM 301 b , a RAM 301 c , a communication interface 301 d , and a circuit part 301 e.
[0121] The CPU 301 a can execute computer programs stored in the ROM 301 b and the computer programs read out in the RAM 301 c.
[0122] The ROM 301 b stores a computer program to be executed by the CPU 301 a , data used in the execution of the computer program, and the like.
[0123] The RAM 301 c is used in reading out the computer program stored in the ROM 301 b . The RAM 301 c is used as a work region of the CPU 301 a when executing these computer programs.
[0124] The communication interface 301 d is, for example, Ethernet (registered trademark) interface. The body controller 10 can transmit and receive data with the data processing unit 12 by using a predetermined communication protocol by means of the communication interface 301 d.
[0125] The circuit part 301 e includes a plurality of drive circuits and a signal processing circuit (not shown). The drive circuit is arranged in correspondence to the specimen preparation member 211 , the first reagent setting member 5 , the detecting member 4 , the stepping motors 357 , 361 , 370 , and the fluid member 9 . Each drive circuit generates a control signal (drive signal) for controlling the corresponding unit (specimen preparation member 211 if drive circuit corresponding to the specimen preparation member 211 ) according to the instruction data provided from the CPU 301 a , and transmits the control signal to the unit. The output signal of the sensor arranged in the unit is provided to the drive circuit, wherein the drive circuit converts the output signal to a digital signal and provides the same to the CPU 301 a . The CPU 301 a generates the instruction data based on the provided output signal of the sensor.
[0126] The signal processing circuit is connected to the detecting member 4 . A detection signal indicating fluorescence intensity is output from the detecting member 4 , and such detection signal is provided to the signal processing circuit. The signal processing circuit executes signal processing such as noise removal process, amplification process, and A/D conversion process on the detection signal. The data on the detection result obtained as a result of the signal processing is provided to the CPU 301 a.
[0127] [3] Diagnosis Support of Cancer
[0128] The operation of the diagnosis support system according to the first embodiment will be described.
(1) Pre-Process by Solubilizing Device B
[0129] Prior to the process by the measuring device A, liquid sample is collected from the tissue containing the malignant tumor extirpated from a cancer patient by using the solubilizing device B. In the procedure thereof, the tissue is first placed in the eppen tube (product name) with a pin set. The eppen tube (product name) is then set in the sample setting member 33 of the solubilizing device B shown in FIG. 1 , and the start button of the operating member 31 is pushed, whereby the pestle 34 lowers to a predetermined position and pushes the tissue in the eppen tube (product name) against the bottom of the eppen tube (product name).
[0130] Solubilizing liquid such as buffer solution containing surfactant and proteolysis enzyme inhibitor agent and the like is automatically or manually injected into the eppen tube (product name) in such state. Thereafter, the tissue is grinded by the rotation of the pestle 34 . The drive of the pestle 34 is stopped after a predetermined time has elapsed, the pestle 34 is moved upward, and thereafter, the eppen tube (product name) is taken out from the sample setting member 33 . The solubilized content in the eppen tube (product name) is then set in the centrifugal machine, and the obtained supernatant solution is manually collected as a sample.
(2) Setting of Sample and the Like to the Measuring Device A
[0131] The supernatant solution is placed in two sample containers and diluted at dilution ratio different from each other, and thereafter, the sample containers are set at predetermined positions in the first reagent setting member 5 . Of the two samples, one is the sample for expression level measurement, and the other is the sample for activity value measurement.
[0132] The solid phase tip for protein 101 is set in the tip setting member 1 , and eight columns 201 are respectively set in the specimen preparation member 211 of the activity measurement unit 2 .
(3) Overall Flow of Process by Device
[0133] The overall flow of one example of the process by the device is shown in FIGS. 15 and 16 . In the judgment in the following flowchart, down refers to Yes and right (left) refers to No unless specifically written as “Yes” and “No”. The processes described below are all processes controlled by the control member 77 and the body controller 10 .
[0134] When the power of the device body 20 is turned ON, initialization of the body controller 10 is performed (step S 1 ). In this initialization operation, initialization of the program, return to an origin position for the driving member of the device body 20 , and the like are performed.
[0135] When the power of the data processing unit 12 or the personal computer is turned ON, initialization of the control member 77 is performed (step S 201 ). In this initialization operation, initialization of the program or the like is performed. After the initialization is completed, a menu screen (not shown) including an input screen display button for instructing the display of an input screen is displayed on the display member 79 . The user can operate the input member 78 to select the input screen button for instructing the display of the input screen of the menu screen.
[0136] In step S 202 , the control member 77 of the data processing unit 12 determines whether or not the input screen is being displayed. The control member 77 advances the process to step S 205 if determined that the input screen is being displayed (Yes), and advances the process to step S 203 if determined that the input screen is not being displayed (No).
[0137] In step S 203 , the control member 77 of the data processing unit 12 determines whether or not a display instruction of the input screen has been made (that is, whether or not input screen button for instructing the display of the input screen of the menu screen is selected). The control member 77 advances the process to step S 204 if determined that the display instruction of the input screen has been made (Yes), and advances the process to step S 301 if determined that the display instruction of the input screen has not been made (No).
[0138] In step S 204 , the control member 77 of the data processing unit 12 displays the input screen on the display member 79 .
[0139] In step S 205 , the user operates the input member 78 to input sample information such as ID number and age of the cancer patient to be examined. Thereafter, in step S 206 , the information input with the input member 78 are stored in the hard disc 91 g . The instruction to start the measurement is made by having the user operate the input member 78 of the personal computer 12 and select a start button displayed on the input screen.
[0140] In step S 207 , the control member 77 determines whether or not the instruction to start the measurement is made. The control member 77 advances the process to step S 208 if determined that the instruction to start the measurement is made (Yes), and advances the process to step S 301 if determined that the instruction to start the measurement is not made (No). In step S 208 , a measurement start signal is transmitted from the control member 77 to the body controller 10 .
[0141] In step S 2 , the body controller 10 determines whether or not the measurement start signal is received. The body controller 10 advances the process to step S 3 if determined that the measurement start signal has been received (Yes), and advances the process to step S 8 if determined that the measurement start signal has not been received (No).
[0142] In step S 3 , the process to prepare the specimen for expression level measurement is performed. The sample is aspirated from the sample container set in the first reagent setting member 5 in step S 3 . A predetermined process is performed on the aspirated sample, and the specimen for expression level measurement is prepared.
[0143] In step S 4 , the process to prepare the specimen for activity value measurement is performed. The sample is aspirated from the sample container set in the first reagent setting member 5 . A predetermined process is performed on the aspirated sample, and the specimen for activity value measurement is prepared.
[0144] In step S 5 , the tip setting member 1 set with the solid phase tip for protein 101 including the specimen for expression level measurement and the specimen for activity value measurement is moved into the detecting member 4 from the position shown in FIG. 1 .
[0145] In step S 6 , excitation light is irradiated on each well of the solid phase tip for protein 101 , and fluorescence radiated from each specimen is detected.
[0146] In step S 7 , the detected detection result is transmitted from the body controller 10 to the control member 77 of the personal computer 12 .
[0147] In step S 209 , the control member 77 determines whether or not the detection result is received. The control member 77 advances the process to step S 210 if determined that the detection result has been received (Yes). The control member 77 again executes the process of step S 209 if determined that the detection result has not been received (No).
[0148] In step S 210 , the control member 77 executes an analyzing process from the acquired detection result.
[0149] In step S 211 , the control member 77 outputs the specific activity of each CDK and result of recurrence rate calculated in step S 210 and the created distribution diagram as result of analysis, and displays the same on the display member 79 .
[0150] FIG. 20 shows one example of a display screen. In the display screen shown in FIG. 20 , ID number, age, and the like of the cancer patient to be examined are displayed on a display region 601 as information on the cancer patient to be examined. The CDK1 specific activity value and the CDK2 specific activity value of the malignant tumor of the cancer patient to be examined are displayed on an information display region 602 as information on the cancer patient to be examined. A graph having the CDK1 specific activity or first parameter and the CDK 2 specific activity or the second parameter of the malignant tumor of the cancer patient as two axes is displayed on a distribution diagram display region 603 . The result of recurrence rate calculated in step S 210 is displayed on an information display region 604 as information related to recurrence.
[0151] In step S 301 , the control member 77 determines whether or not an input screen of the set values of the value (radius) for determining the sample data extraction range is being displayed. The control member 77 advances the process to step S 305 if determined that the input screen of the set value is being displayed (Yes), and advances the process to step S 302 if determined that the input screen of the set value is not being displayed (No).
[0152] In step S 302 , the control member 77 determines whether or not a display instruction of the input screen of the set value has been made. The control member 77 advances the process to step S 303 if determined that the display instruction of the input screen of the set value has been made (Yes), and advances the process to step S 307 if determined that the display instruction of the input screen of the set value has not been made (No).
[0153] In step S 303 , the RAM 91 g of the control member 77 reads out data of the value (radius) for determining the sample data extraction range stored in the first database 91 i of the hard disc 91 g.
[0154] In step S 304 , the input screen of the set value is displayed on the display member 79 by the control member 77 . New values are input for the set values of the value for determining the sample data extraction range by having the user operate the input member 78 .
[0155] In step S 305 , the control member 77 determines whether or not the input of the set value has been made. The control member 77 advances the process to step S 306 if determined that the input of the set value has been made (Yes), and advances the process to step S 307 if determined that the input of the set value has not been made (No).
[0156] In step S 306 , the input new set value is stored in the first database 91 i of the hard disc 91 g.
[0157] In step S 307 , the control member 77 determines whether or not an instruction to shutdown is accepted. The control member 77 advances the process to step S 308 if determined that the instruction to shutdown is accepted (Yes), and returns the process to step S 202 if determined that the instruction to shutdown is not accepted (No). In step S 308 , a shutdown signal is transmitted from the control member 77 to the body controller 10 . In step S 309 , the control member 77 performs the process of shutting down the personal computer 12 , and completes the process.
[0158] In step S 8 , the body controller 10 determines whether or not the shutdown signal has been received. The body controller 10 advances the process to step S 9 if determined that the shutdown signal has been received (Yes), and returns the process to step S 2 if determined that the shutdown signal has not been received (No). In step S 9 , the body controller 10 shuts down the device body 20 , and terminates the process.
(4) Preparation Process of Expression Level Measurement Specimen
[0159] The flow of one example of the preparation process of the expression level measurement specimen in step S 3 is shown in FIG. 17 .
[0160] First, in step S 21 , the preservation solution stored in advance in each well of the solid phase tip for protein is discharged, and the inside of each well is washed. The washing is performed by injecting washing liquid to each well from the upper side through the pipette of the dispensing mechanism member 3 , and aspirating the injected washing liquid through the porous film by negative pressure from the lower side of the solid phase tip for protein. The following washing step is similarly carried out.
[0161] The sample for the expression level measurement is aspirated with the pipette from the sample container set in the first reagent setting member 5 , which sample is injected to a plurality of predetermined wells, and the sample is aspirated by negative pressure from the lower side of the solid phase tip for protein. The protein is solid-phased at the porous film of the solid phase tip for protein (step S 22 ).
[0162] Similar to step S 21 , the inside of the predetermined well is washed with the washing liquid. Accordingly, the components other than the protein are removed from the porous film of the solid phase tip for protein (step S 23 ).
[0163] Subsequently, the blocking liquid is injected to the predetermined well, and after leaving it for 15 minutes or longer (e.g., for 30 minutes), the blocking liquid remaining in the well is discharged (step S 24 ). Accordingly, the fluorescence labeled CDK1 antibody (fluorescence labeled CDK1 antibody) and the fluorescence labeled CDK2 antibody (fluorescence labeled CDK2 antibody) are prevented from being solid-phased at the site of the porous film at which the protein is not solid-phased. The commercially available fluorescence labeled CDK1 antibody and the fluorescence labeled CDK2 antibody may be used.
[0164] The fluorescence labeled CDK1 antibody and the fluorescence labeled CDK2 antibody are respectively injected to the predetermined well. In this case, each fluorescence labeled antibody is injected into two wells. The injected fluorescence label is discharged after 20 to 30 minutes have elapsed and the reaction of the fluorescence labeled antibody and the protein (CDK1 or CDK2) solid-phased on the porous film is terminated (step S 25 ).
[0165] Lastly, similar to step S 23 , the inside of the predetermined well is washed with the washing liquid (Step S 26 ).
(5) Preparation Process of Activity Value Measurement Specimen
[0166] FIG. 18 shows a flow of one example of the preparation process of the activity value measurement specimen in step S 4 . In the preparation process of the activity value measurement specimen, four specimen preparation members 211 are arranged on the near side in the figure and four specimen preparation members 211 are arranged on the far side in the figure as the activity measurement unit 2 shown in FIG. 1 . Each specimen preparation member 211 of the activity measurement unit 2 includes a first specimen preparation member (Ac 1 ), a second specimen preparation member (Ac 2 ), a third specimen preparation member (Ac 3 ), and a fourth specimen preparation member (Ac 4 ), from the left on the far side of the figure, and a fifth specimen preparation member (Ac 5 ), a sixth specimen preparation member (Ac 6 ), a seventh specimen preparation member (Ac 7 ), and an eighth specimen preparation member (Ac 8 ), from the left on the near side of the figure.
[0167] For each of the first to the eighth specimen preparation members (Ac 1 to Ac 8 ), a buffer or a washing reagent is injected to the opening 205 with the pipette of the dispensing mechanism member 3 . For each of the first to the eighth specimen preparation members (Ac 1 to Ac 8 ), the syringe pump 214 and the electromagnetic valve 225 operate as described above, so that the buffer of the liquid storage member 204 passes through the carrier 206 into the flow channel 223 , and again passes through the carrier 206 and returns to the liquid storage member 204 . The buffer returned to the liquid storage member 204 in all the columns 201 is aspirated and discarded with the pipette of the dispensing mechanical member 3 (step S 31 ).
[0168] Immunoprecipitation (immunoreaction between antibody and CDK) is then performed (step S 32 ). First, the sample 1 for the activity value measurement is aspirated with one pipette and the sample 2 for the activity value measurement is aspirated with another pipette from one sample container set in the first reagent setting member 5 .
[0169] As shown in FIG. 26 , the sample 1 for the activity value measurement aspirated from the sample container is first injected to the liquid storage member 204 of the first specimen preparation member (Ac 1 ). The sample 1 is sent to the carrier 206 of the first specimen preparation member (Ac 1 ) by operating the syringe pump 214 and the electromagnetic valve 225 as described above. In this case, the sample 1 reciprocates in the carrier 206 of the column 201 once by reciprocating the piston 218 up and down once (aspiration→discharge).
[0170] The sample 2 for activity value measurement aspirated from the sample container is first injected to the liquid storage member 204 of the fifth specimen preparation member (Ac 5 ). The sample 2 is similarly sent to the carrier 206 of the fifth specimen preparation member (Ac 5 ), similar to the above.
[0171] Neither antibody of the CDK1 nor antibody of the CDK2 is immobilized on the carrier 206 of the columns 201 of the first specimen preparation member (Ac 1 ) and the fifth specimen preparation member (Ac 5 ). Therefore, the CDK1 and the CDK2 are not solid-phased in the first specimen preparation member (Ac 1 ) and the fifth specimen preparation member (Ac 5 ), the sample 1 containing the CDK1 and the CDK2 is stored in the column 201 of the first specimen preparation member (Ac 1 ), and the sample 2 containing the CDK1 and the CDK2 is stored in the column 201 of the fifth specimen preparation member (Ac 5 ).
[0172] The sample 1 stored in the column 201 of the first specimen preparation member (Ac 1 ) is then aspirated with the pipette, and injected to the liquid storage member 204 of the third specimen preparation member (Ac 3 ). The sample 1 is then sent to the carrier 206 of the third specimen preparation member (Ac 3 ), similar to the above.
[0173] The sample 2 stored in the column 201 of the fifth sample specimen member (Ac 5 ) is aspirated with the pipette, and injected to the liquid storage member 204 of the fourth specimen preparation member (Ac 4 ). The sample 2 is then sent to the carrier 206 of the fourth specimen preparation member (Ac 4 ), similar to the above.
[0174] The antibody of the CDK1 is immobilized to the carriers 206 of the columns 201 of the third specimen preparation member (Ac 3 ) and the fourth specimen preparation member (Ac 4 ). Therefore, the CDK1 is solid-phased but the CDK2 is not solid-phased in the third specimen preparation member (Ac 3 ) and the fourth specimen preparation member (Ac 4 ), the sample 1 not containing the CDK1 but containing the CDK2 is stored in the column 201 of the third specimen preparation member (Ac 3 ), and the sample 2 not containing the CDK1 but containing the CDK2 is stored in the column 201 of the fourth specimen preparation member (Ac 4 ).
[0175] The sample 1 stored in the column 201 of the third specimen preparation member (Ac 3 ) is then aspirated with the pipette, and injected to the liquid storage member 204 of the seventh specimen preparation member (Ac 7 ). The sample 1 is then sent to the carrier 206 of the seventh specimen preparation member (Ac 7 ), similar to the above.
[0176] The sample 2 stored in the column 201 of the fourth specimen preparation member (Ac 4 ) is aspirated with the pipette, and injected to the liquid storage member 204 of the eighth specimen preparation member (Ac 8 ). The sample 2 is then sent to the carrier 206 of the eighth specimen preparation member (Ac 8 ), similar to the above.
[0177] The antibody of the CDK2 is immobilized to the carrier 206 of the columns 201 of the seventh specimen preparation member (Ac 7 ) and the eighth specimen preparation member (Ac 8 ). Therefore, the CDK2 is solid-phased in the seventh specimen preparation member (Ac 7 ) and the eighth specimen preparation member (Ac 8 ), and thus the sample 1 not containing the CDK1 nor the CDK2 is stored in the column 201 of the seventh specimen preparation member (Ac 7 ), and the sample 2 not containing the CDK1 nor the CDK2 is stored in the column 201 of the eighth specimen preparation member (Ac 8 ).
[0178] The sample 1 and the sample 2 stored in the columns 201 of the seventh specimen preparation member (Ac 7 ) and the eighth specimen preparation member (Ac 8 ) are respectively aspirated with the pipette, and disposed in the waste bath 7 .
[0179] The first specimen preparation member (Ac 1 ) and the fifth specimen preparation member (Ac 5 ) are used for activity measurement of the background, the third specimen preparation member (Ac 3 ) and the fourth specimen preparation member (Ac 4 ) are used for activity measurement of the CDK1, and the seventh specimen preparation member (Ac 7 ) and the eighth specimen preparation member (Ac 8 ) are used for activity measurement of the CDK2.
[0180] Therefore, the background activity measurement, the CDK1 activity measurement, and the CDK2 activity measurement can be performed with small amount of sample by injecting the sample remaining in the column into other columns.
[0181] The buffer 1 is then sent to the columns 201 to wash and remove unnecessary components in the sample (step S 33 ).
[0182] Subsequently, since the buffer 1 influences enzyme reaction executed in step S 25 , the buffer 2 is sent to the column 201 to wash off the components of the buffer 1 with the main aim of creating a condition for the relevant enzyme reaction (step S 34 ).
[0183] The substrate reaction solution containing substrate Histon H 1 and ATPγS is then injected to the column 201 , and the piston 219 is allowed to reciprocate once (step S 35 ). The liquid pushed out from the lower side of the column 201 is stored in the column 201 as it is. According to such step, the phosphate group is introduced to the Histon H 1 with CDK1 and CDK2 as enzymes. The amount of phosphate group is influenced by the strength (i.e., activity value) of the work of the CDK1 or the CDK2 as enzyme, and thus the activity values of the CDK1 or the CDK2 can be obtained by measuring the amount of phosphate group. The background activity value obtained using the first specimen preparation member (Ac 1 ) and the fifth specimen preparation member (Ac 5 ) shown in FIG. 26 is used to perform background correction as hereinafter described.
[0184] The fluorescent labeled reagent is dispensed directly into the column 201 from the upper of the column 201 with the pipette to bind the fluorescent labeled substance to the phosphate group introduced into the Histon H 1 (step S 36 ). In this case, the pipette repeats aspiration and discharge of liquid in the column for a predetermined time to stir the liquid in the column 201 .
[0185] A reaction stopping solution is directly dispensed to the column 201 similar to the fluorescent labeled reagent after elapse of a predetermined time (e.g., for twenty minutes) from the start of step S 26 . The liquid in the column 201 is stirred by repeating aspiration and discharge of the liquid in the column for a predetermined time similar to step S 26 (step S 37 ). The binding of fluorescent label is thereby stopped.
[0186] The liquid in the columns 201 of the first specimen preparation member (Ac 1 ), the third specimen preparation member (Ac 3 ), the fourth specimen preparation member (Ac 4 ), the fifth specimen preparation member (Ac 5 ), the seventh specimen preparation member (Ac 7 ), and the eighth specimen preparation member (Ac 8 ) are injected to six wells of the solid phase tip for protein 101 , and the solid phase tip for protein 101 is aspirated from the lower side (step S 38 ). The Histon H 1 containing phosphate group bound with fluorescent labeled substance is thereby solid-phased on the porous film of the phase tip for protein 101 .
[0187] The well is washed similar to step S 21 in the preparation process of expression level measurement specimen (step S 39 ).
[0188] Lastly, an operation of dispensing and discharging quenching reagent for quenching (background quenching) the fluorescent light based on the fluorescent labeled substance that did not bind to the phosphate group introduced into the Histon H 1 into wells is repeated six times (step S 40 ).
(6) Analyzing Process
[0189] As shown in the flowchart of FIG. 19 , in the step of analyzing process (step S 210 ), analysis is performed from the fluorescence intensity obtained in the detecting member, and the result of analysis is output to the display member 79 .
[0190] First, in step S 401 , the control member 77 acquires two fluorescence intensities for each of activity of CDK1, expression of CDK1, activity of CDK2, expression of CDK2, activity of background, and expression of background through the body controller 10 from the light receiving system of the detecting member 4 .
[0191] Thereafter, the control member 77 calculates the average value of the fluorescence intensities obtained two at a time for each item in step S 402 .
[0192] In step S 403 , the background activity (average value) is subtracted from the fluorescence intensity (average value) of the CDK1 activity. The background activity (average value) is subtracted from the fluorescence intensity (average value) of the CDK2 activity. The background correction is thereby performed for the CDK1 activity and the CDK2 activity. The background correction is similarly performed for the CDK1 expression and the CDK2 expression.
[0193] In step S 404 , the control member 77 acquires the expression level and the activity value by using standard curve for each item. The standard curve is data for converting fluorescence intensity to expression level or activity value. The standard curve is created in advance by using two or more types of samples which expression level or activity value is known when the lot of the reagent is changed, and stored in the hard disc 91 g of the control member 77 .
[0194] In step S 405 , the control member 77 calculates the CDK1 specific activity and the CDK2 specific activity according to equation (III):
[0000] CDK1 specific activity=CDK1 activity value/CDK1 expression level
[0000] And equation (IV):
[0000] CDK2 specific activity=CDK2 activity value/CDK2 expression level
[0195] Thereafter, in step S 406 , the control member 77 creates a distribution diagram having a logarithm (log) of the CDK1 specific activity and a logarithm (log) of the CDK2 specific activity on two axes, and determines the sample data extraction range based on the calculated CDK1 specific activity and CDK2 specific activity. The sample data extraction range is a predetermined numerical range including the CDK1 specific activity and the CDK2 specific activity of the malignant tumor of the cancer patient to be examined. Specifically, the sample data extraction range is determined as a circle having a radius of 0.3 with a point corresponding to the logarithm (log) of the CDK1 specific activity and the logarithm (log) of the CDK2 specific activity of the malignant tumor of the cancer patient to be examined as a center in the distribution diagram having the logarithm (log) of the CDK1 specific activity and the logarithm (log) of the CDK2 specific activity on two axes. The value of radius corresponds to the numerical values of the horizontal axis and the vertical axis in the distribution diagram.
[0196] The CDK1 specific activity and the CDK2 specific activity of the malignant tumor of the cancer patient to be examined are collectively referred to as “data on cancer patient to be examined”.
[0197] In step S 407 , the control member 77 reads out sample data in which the measurement value such as activity value and expression level of the cancer patient and the clinical information on the relevant patient are corresponded from the second database 91 j of the hard disc 91 g.
[0198] In step S 408 , the control member 77 extracts the sample data based on the sample data extraction range determined in step S 406 .
[0199] In step S 409 , the control member 77 calculates a recurrence rate based on the sample data extracted in step S 408 . Specifically, the recurrence rate can be calculated by counting the total number of sample data extracted in step S 408 and calculating the proportion of the sample data related to the patient in whom the cancer recurred, of the sample data. The recurrence rate is shown in percentage (%) with the total number of sample data as 100.
[0200] In step S 211 , the control member 77 executes a process for displaying a screen as shown in FIG. 20 on the display member. The screen includes an identification information display region 601 , a CDK data display region 602 , a distribution diagram display region 603 , and a recurrence rate display region 604 .
[0201] The identification information display region 601 displays ID number and age of the cancer patient to be examined as information on the cancer patient to be examined.
[0202] The CDK data display region 602 displays the CDK1 specific activity and the CDK2 specific activity of the malignant tumor of the cancer patient to be examined as information on the cancer patient to be examined.
[0203] The recurrence rate display region 604 displays the recurrence rate calculated in step S 210 .
[0204] The distribution diagram display region 603 displays a graph having the CDK1 specific activity and the CDK2 specific activity as two axes. On the distribution diagram, the sample data ( 401 , 402 ) of the cancer patient administered with anthracycline anticancer drugs of the sample data stored in the storage member are drawn.
[0205] The sample data 401 is plotted with sample data of the patient in whom the cancer recurred by the 1500 th day after being administered with the anthracycline anticancer drug. The sample data of the patient in whom the cancer recurred is displayed by dots surrounded by a circle as shown in FIG. 20 . The sample data 402 is plotted with sample data of the patient in whom recurrence of cancer is not recognized after being administered with the anthracycline anticancer drug. The sample data of the patient in whom recurrence of cancer is not recognized is displayed only by dots as shown in FIG. 20 .
[0206] The data on cancer patient to be examined 400 is plotted on the distribution diagram.
[0207] A sample data extraction range 403 determined in S 406 is displayed on the distribution diagram. The distribution diagram of the display screen shown in FIG. 20 displays the CDK1 specific activity on the horizontal axis by log and the CDK2 specific activity on the vertical axis by log.
[0208] Taking the graph shown in FIG. 20 by way of example, the sample data of the cancer patient in whom the cancer recurred by the 1500 th day after being administered with the anthracycline anticancer drug tends to concentrate at a specific region of the graph (middle in the graph of FIG. 20 ). The data on cancer patient to be examined 400 is positioned in a region where the sample data of the patient in whom the cancer recurred concentrates. Therefore, the state of the malignant tumor of the cancer patient to be examined can be predicted to be a state similar to the malignant tumor of the cancer patient in whom the cancer recurred after being administered with the anthracycline anticancer drug. The result of calculating the recurrence rate based on the total number of sample data contained in the sample data extraction range 403 determined on the basis of the data on cancer patient to be examined 400 and the proportion of the sample data of the cancer patient in whom the recurrence of cancer is recognized is as displayed on the recurrence rate display region 604 . In the example shown in FIG. 20 , the recurrence rate of cancer in the cancer patient to be examined is 63%.
[0209] As shown in FIG. 20 , the sample data of the patient administered with the anthracycline anticancer drug and in whom recurrence of cancer is recognized is distributed concentrating on the specific region of the two-axle graph based no the CDK1 specific activity and the CDK2 specific activity. That is, the features of the anticancer effect by the anthracycline anticancer drug are reflected on the two-axes graph of the CDK1 specific activity and the CDK2 specific activity. Thus, the sample data of the cancer patient having a specific feature in the anticancer effect by the anthracycline anticancer drug can be extracted by plotting the data cancer patient to be examined on such two-axes graph and extracting the sample data based on the plotted data on cancer patient to be examined, and thus the recurrence rate reflecting the state of the malignant tumor of the cancer patient to be examined can be obtained by calculating the recurrence rate of the cancer in the cancer patient to be examined based on the information related to the recurrence of cancer contained in the extracted sample data.
[0210] Therefore, the information on the recurrence rate provided by the device according to the first embodiment is information useful in predicting the effectiveness of the anthracycline anticancer drug in the cancer patient to be examined, and is information also useful in determining the treatment policy of the cancer patient to be examined. Therefore, the user can obtain diagnosis support information at higher precision by the diagnosis support device according to the first embodiment.
[0211] The device of the first embodiment is configured including the measurement unit 501 for measuring the activity value and the expression level of the CDK1 as well as the activity value and the expression level of the CDK2, and the solubilizing device B for obtaining a sample that can be processed in the measuring device A from a biological specimen (malignant tumor), but is not limited to such configuration. For instance, a configuration of inputting the activity values and the expression levels of the CDK1 and the CDK2 separately measured by other methods or other devices from the malignant tumor of the cancer patient to be examined through the personal computer, and performing analysis by using the input values may be adopted. Alternatively, a configuration of obtaining the CDK1 specific activity and the CDK2 specific activity in advance from the separately measured activity value and the expression level, and performing analysis by accepting the input of such values may be adopted.
[0212] The first embodiment has a configuration in which the control member 77 acquires two fluorescence intensities for each of the activity of the CDK1, the expression of the CDK1, the activity of the CDK2, the expression of the CDK2, the activity of the background, and the expression of the background, and calculates the average value of the fluorescence intensity obtained by twos for each item, but is not limited thereto, and may have a configuration in which the control member 77 acquires three or more fluorescence intensities for each of the activity of the CDK1, the expression of the CDK1, the activity of the CDK2, the expression of the CDK2, the activity of the background, and the expression of the background, and calculates the average value of the fluorescence intensity of each item.
[0213] One fluorescence intensity for each of the activity of the CDK1, the expression of the CDK1, the activity of the CDK2, the expression of the CDK2, the activity of the background, and the expression of the background may be acquired. In this case, the background correction of the activity and the expression of the CDK1 and the activity and the expression of the CDK2 is performed using the fluorescence intensity of each item acquired by one instead of the average value of each item in step S 403 .
[0214] In the first embodiment, the control member 77 calculates the CDK1 specific activity and the CDK2 specific activity in step S 405 , but the present invention is not limited thereto. For instance, in step S 405 , the control member 77 may calculate the inverse number of the CDK1 specific activity and the increase number of the CDK2 specific activity according to the following equation (V) in place of the CDK1 specific activity and the CDK2 specific activity:
[0000] Inverse number of CDK1 specific activity=CDK1 expression level/CDK1 activity value
[0000] and equation (VI)
[0000] Inverse number of CDK2 specific activity=CDK2 expression level/CDK2 activity value
[0215] The device of the first embodiment is configured such that the user such as doctor appropriately sets the radius of the sample data extraction range, and the sample data extraction range is determined as a circle having the set radius. The sample data extraction range is desirably determined to a size that the minimum required number of samples for ensuring the statistical reliability can be ensured. Therefore, from the standpoint of ensuring reliability, the information on the number of samples contained in the sample data extraction range may be displayed simultaneously with the display of the sample data extraction range on the display screen so that the minimum required number of samples can be ensured in the sample data extraction range. The user can then easily reset the radius of the sample data extraction range so that an appropriate number of samples can be ensured with reference to the information on the number of samples displayed on the screen.
[0216] The device of the first embodiment may automatically determine the radius of the sample data extraction range. If the device automatically sets the radius, a configuration of determining the sample data extraction range so as to satisfy the following conditions (I) to (III) is preferable.
[0217] (I) Having a range from which sample data of medically and statistically meaningful number can be extracted with the data on cancer patient to be examined as the center;
[0218] (II) Setting a region including the data on cancer patient to be examined and having a size capable of including the measurement error/standard deviation by the device;
[0219] (III) Setting a region including the data on cancer patient to be examined, and having a predetermined size including the measurement error/standard deviation of the CDK1 specific activity and the CDK2 specific activity obtained by performing one or more measurements with respect to one predetermined item for one specimen.
[0220] The diagnosis support information having medical meaning and having high precision can be provided by determining the sample data extraction range as in (I) by the control member 77 . The lowering in precision caused by the measurement error by the device can be prevented by determining the sample data extraction range as in (II) by the control member 77 . The lowering in precision caused by variation in the measurement values by the measurement method can be prevented by determining the sample data extraction range as in (III) by the control member 77 . In step S 406 , the sample data extraction range is determined as above, and thus information useful in predicting the effectiveness of the anthracycline anticancer drug can be provided at high precision.
[0221] In the device of the first embodiment, the sample data extraction range is a circle having the data on cancer patient to be examined as the center, but is not limited thereto. The sample extraction range may be other shapes such as square or ellipse having the data on cancer patient to be examined as the center.
[0222] In the device of the first embodiment, the sample data extraction range is appropriately determined based on the data on cancer patient to be examined, but is not limited to such configuration. For instance, the numerical range related to the CDK1 specific activity and the CDK2 specific activity that may be the candidates of the sample data extraction range may be set in plurals in advance, and the numerical range to which the data on cancer patient to be examined belongs, of the numerical ranges, may be determined as the sample data extraction range. There may be a configuration of setting, as such numerical range, a reference value to the CDK1 specific activity and the CDK2 specific activity that can divide the cancer patients administered with the anthracycline anticancer drugs into at least two groups of different recurrence risks, and setting two ranges of the range of greater than or equal to the reference value and the range smaller than the reference value.
[0223] The reference value can be set to a statistically significant value by obtaining the CDK1 specific activity and the CDK2 specific activity of the malignant tumor of the cancer patient administered with the anthracycline anticancer drugs from a plurality of cases. Second and third embodiments using the reference value obtained in such manner are described below.
Second Embodiment
[0224] FIG. 21 is a schematic explanatory view of a graph shown in the distribution diagram display region in the display screen of the diagnosis support device of the second embodiment. In the diagnosis support device of the second embodiment, the reference value is set in advance based on the activity values and the expression levels of the CDK1 and the CDK2. In FIG. 21 , a reference line 416 based on the reference value is drawn. In FIG. 21 , the sample data ( 414 , 415 ) of the cancer patient administered with the anthracycline anticancer drug are drawn.
[0225] The sample data 414 is plotted with the sample data of the cancer patient in whom the cancer recurred by the 1500 th day after being administered with the anthracycline anticancer drug. The sample data 415 is plotted with the sample data of the cancer patient in whom the recurrence of cancer is not recognized after being administered with the anthracycline anticancer drug. Furthermore, data on cancer patient to be examined 410 is plotted in FIG. 21 .
[0226] A region 411 , B region 412 , and C region 413 are obtained as the sample data extraction range by the reference value (reference line) 416 of FIG. 21 . The recurrence rate of the cancer in each sample data extraction range is calculated based on the presence of recurrence of the sample data contained in each sample data extraction range. This result is shown in table 2.
[0000]
TABLE 2
Total number of sample
Number of recurred
Region
data
sample data
Recurrence rate
A
12
1
8%
B
28
16
57%
C
14
2
14%
[0227] As shown in table 2, the recurrence rate of the A region is 8%, the recurrence rate of the B region is 57%, and the recurrence rate of the C region is 14%. In the example shown in FIG. 21 , the data on cancer patient to be examined 410 is plotted in the region (B region) where the sample data of the cancer patient in whom the recurrence of cancer is recognized is concentrated. Thus, the state of the malignant tumor of the cancer patient to be examined can be assumed as a state similar to the malignant tumor of the cancer patient in whom the cancer recurred after being administered with the anthracycline anticancer drug. The data on cancer patient to be examined 410 belongs to the B region, and thus the recurrence rate of the cancer patient to be examined is calculated as 57% from table 2.
Third Embodiment
[0228] FIG. 22 is a schematic explanatory view of a graph shown in the distribution diagram display region in the display screen of the diagnosis support device of the third embodiment. In the diagnosis support device of the third embodiment, the reference value 426 is set in advance based on the information related to recurrence contained in the sample data of the cancer patient administered with the anthracycline anticancer drug. In FIG. 22 , the reference value 426 (reference line) is drawn. In FIG. 22 , the sample data ( 424 , 425 ) of the cancer patient administered with the anthracycline anticancer drug are plotted. Specifically, the sample data 424 is plotted with the sample data of the cancer patient in whom the cancer recurred by the 1500 th day after being administered with the anthracycline anticancer drug. The sample data 425 is plotted with the sample data of the cancer patient in whom the recurrence of cancer is not recognized after being administered with the anthracycline anticancer drug. Furthermore, data on cancer patient to be examined 420 is plotted in FIG. 22 .
[0229] A region 421 , B region 422 , and C region 423 are obtained as the sample data extraction range by the reference value (reference line) 426 of FIG. 22 . The result of calculating the recurrence rate based on the presence of recurrence of cancer of the sample data contained in each sample data extraction range divided as above is shown in table 3.
[0000]
TABLE 3
Total number of sample
Number of recurred
Region
data
sample data
Recurrence rate
A
12
1
8%
B
14
3
21%
C
28
14
50%
[0230] As shown in table 3, the recurrence rate of the A region is 8%, the recurrence rate of the B region is 21%, and the recurrence rate of the C region is 50%. In the example shown in FIG. 22 , the data on cancer patient to be examined 420 is plotted in the region (C region) where the sample data of the cancer patient in whom the cancer recurred is concentrated. Thus, the state of the malignant tumor of the cancer patient to be examined can be assumed as a state similar to the malignant tumor of the cancer patient in whom the cancer recurred after being administered with the anthracycline anticancer drug. The data cancer patient to be examined 420 belongs to the C region, and thus the recurrence rate of the cancer patient to be examined is calculated as 50% from table 3.
[0231] A reference value for classifying the cancer patient not treated with anticancer drug into groups of different recurrence risks may be set. An example using such reference value is shown in FIG. 24 . FIG. 24 is a graph showing the cancer patient not treated with anticancer drug classified into three groups of different recurrence risks.
[0232] In FIG. 24 , a reference value 446 capable of dividing the cancer patients treated with hormone therapy without being treated with anticancer drug into three groups of different recurrence risks is shown. The reference value 446 is calculated based on the sample data ( 444 , 445 ) of the cancer patient treated with hormone therapy. Specifically, the sample data 444 is plotted with the sample data of the cancer patient in whom the cancer recurred by the 1500 th day after being treated with hormone therapy. The sample data 445 is plotted with the sample data of the cancer patient in whom the recurrence of cancer is not recognized after being treated with the hormone therapy.
[0233] The reference value 446 in FIG. 24 includes a first reference value, a second reference value, a third reference value, and a fourth reference value. Specifically, the reference values are as described below.
[0234] First reference value: ratio (specific activity ratio) of CDK1 specific activity and CDK2 specific activity is 2.8
[0235] Second reference value: specific activity of CDK1 is 5
[0236] Third reference value: specific activity of CDK1 is 20
[0237] Fourth reference value: specific activity of CDK1 is 90
[0238] The cancer patients treated with hormone therapy without being treated with anticancer drug can be divided into three groups of different recurrence risks by the reference value 446 . Specifically, the cancer patients can be classified into a high risk group H (region 441 ) in which the recurrence rate is relatively high, a low risk group L (region 443 ) in which the recurrence rate is relatively low, and an intermediate risk group I (region 442 ) in which the recurrence rate is intermediate. The recurrence rate is calculated based on the information on the presence of recurrence of the sample data of the cancer patients treated with hormone therapy contained in the high risk group H, the intermediate risk group I, and the low risk group L of the graph of FIG. 24 . The result is shown in table 4.
[0000]
TABLE 4
Total number of
Number of recurred
Risk group
sample data
sample data
Recurrence rate
L
73
2
3%
I
47
3
6%
H
66
10
15%
[0239] A fourth embodiment employing the reference value shown in FIG. 24 as the reference value for classifying the cancer patient administered with the anthracycline anticancer drug into groups of different recurrence risks is described below.
Fourth Embodiment
[0240] FIG. 23 is a schematic explanatory view of a graph shown in the distribution diagram display region in the display screen of the diagnosis support device of the fourth embodiment. In the diagnosis support device of the fourth embodiment, in the example shown in FIG. 23 , a reference value 436 for classifying the cancer patient administered with anthracycline anticancer drug into groups of different recurrence risks is set in advance. The reference value 436 is drawn in FIG. 23 . As described above, the reference value 436 is applied with the reference value (reference value 446 of FIG. 24 ) for classifying the cancer patient treated with hormone therapy without being treated with anticancer drug into groups of different recurrence risks. That is, the reference value 436 in FIG. 23 includes a first reference value, a second reference value, a third reference value, and a fourth reference value, and specifically, the reference values are as described below.
[0241] First reference value: ratio (specific activity ratio) of CDK1 specific activity and CDK2 specific activity is 2.8
[0242] Second reference value: specific activity of CDK1 is 5
[0243] Third reference value: specific activity of CDK1 is 20
[0244] Fourth reference value: specific activity of CDK1 is 90
[0245] In FIG. 23 , the sample data ( 434 , 435 ) of the cancer patient administered with the anthracycline anticancer drug are plotted. Specifically, the sample data 434 is plotted with the sample data of the cancer patient in whom the cancer recurred by the 1500 th day after being administered with the anthracycline anticancer drug. The sample data 435 is plotted with the sample data of the cancer patient in whom the recurrence of cancer is not recognized after being administered with the anthracycline anticancer drug. Furthermore, data cancer patient to be examined 430 is plotted in FIG. 23 .
[0246] A region 431 , B region 432 , and C region 433 are obtained as the sample data extraction range by the reference value 436 of FIG. 23 . The recurrence rate is calculated based on the information on the presence of recurrence of the sample data of the cancer patient administered with the anthracycline anticancer drug contained in each sample data extraction range divided in the above manner. This result is shown in table 5.
[0000]
TABLE 5
Total number of
Number of recurred sample
Region
sample data
data
Recurrence rate
A
18
1
6%
B
14
6
43%
C
22
12
55%
[0247] As shown in table 5, the recurrence rate of the A region is 6%, the recurrence rate of the B region is 43%, and the recurrence rate of the C region is 55%. From the result of FIG. 23 and table 5, it can be seen that the sample data 434 of the cancer patient in whom the cancer recurred after being administered with anthracycline anticancer drug is barely seen in the A region. The A region 431 of FIG. 23 corresponds to the high risk group H of FIG. 24 . Therefore, if the data on cancer patient to be examined is contained in the A region 431 , the state of the malignant tumor of the cancer patient to be examined can be predicted as a state similar to the malignant tumor of the cancer patient in whom the cancer recurred after being treated with hormone treatment without being treated with anticancer drug, and a state similar the malignant tumor of the cancer patient in whom the cancer did not recur after being administered with the anthracycline anticancer drug. The cancer patient to be examined thus can be predicted as having high recurrence risk unless administered with anticancer drug, but recurrence can be prevented by administering the anthracycline anticancer drug. In other words, it is suggested that the anthracycline anticancer drug can be predicted to be effective for the relevant cancer patient to be examined.
[0248] From the result of FIG. 23 and table 5, it can be seen that the sample data 434 of the cancer patient in whom the cancer recurred after being administered with anthracycline anticancer drug is concentrated in the B region and the C region. The B region 432 of FIG. 23 corresponds to the intermediate risk group I of FIG. 24 , and the C region 433 of FIG. 23 corresponds to the low risk group L of FIG. 24 . Therefore, if the data on cancer patient to be examined is contained in the B region 432 or the C region 433 , the state of the malignant tumor of the cancer patient to be examined can be predicted as a state similar to the malignant tumor of the cancer patient in whom the cancer recurred after being administered with anthracycline anticancer drug. Then, it can be predicted that it is difficult to prevent recurrence even if the anthracycline anticancer drug is administered in the cancer patient to be examined. In other words, it is suggested that the anthracycline anticancer drug can be predicted to be ineffective for the relevant cancer patient to be examined.
[0249] For instance, the data on cancer patient to be examined 430 is contained in the C region 433 in FIG. 23 . Thus, the state of the malignant tumor of the cancer patient to be examined can be predicted as a state similar to the malignant tumor of the cancer patient in whom the cancer recurred after being administered with anthracycline anticancer drug.
[0250] The sample data extraction range is determined as the C region 433 based on the data on cancer patient to be examined 430 , and the recurrence rate of the cancer of the cancer patient to be examined is calculated based on the information on the presence of recurrence of the sample data contained in the C region 433 . As a result, a value of high recurrence rate of 55% was indicated.
[0251] Therefore, the reference value corresponding to the CDK1 specific activity and the CDK2 specific activity for classifying the cancer patients not treated with anticancer drug into groups of different recurrence risks is suggested to be used as the reference value for classifying the cancer patients administered with the anthracycline anticancer drug into groups of different recurrence risks.
[0252] The recurrence rate calculated as above can be predicted as the recurrence rate reflecting the state of the malignant tumor of the cancer patient to be examined. That is, the recurrence rate calculated as above can be considered as the recurrence rate of the cancer predicted when the anthracycline anticancer drug is administered to the cancer patient to be examined. Therefore, the information on the recurrence rate provided by the device according to the fourth embodiment is information useful in predicting the effectiveness of the anthracycline anticancer drug in the cancer patient to be examined, and may be information useful in determining the treatment policy of the cancer patient to be examined.
[0253] The reference values of the second to the fourth embodiments may be appropriately set by users such as doctors.
[0254] In each of the second to the fourth embodiments, the sample data extraction range for extracting the sample data by displaying the set value input screen and inputting the set value is set, but is not limited to such configuration. The set value can be input with the following configuration.
[0255] FIG. 27 is a view showing one example of the set value input screen. First, the cursor C is moved to a predetermined position on the distribution diagram with the operation of the input member 78 (e.g., mouse) with the distribution diagram showing the sample data displayed on the set value input screen, and the mouse is double clicked to set the first set value P 1 . Similar operation is performed to input the second set value. The mouse is then right clicked to display a selection menu M, and the item of the displayed “reference line input” is selected to set a reference line L connecting the first set value and the second set value. The reference line as shown in FIGS. 22 and 23 can be easily set by repeating such operations.
[0256] The “reference line input” is selected after inputting three or more set values by the input member 78 , so that a curve approximate to a line segment connecting each set value is set as the reference line and displayed on the distribution diagram. The reference line shown in FIG. 21 is easily set and the setting of the sample data extraction range is facilitated through such method.
[0257] [4] Prediction of Effectiveness of Anthracycline Anticancer Drug
[0258] As described in [3], the information related to the recurrence obtained by the diagnosis support device is information useful in predicting the effectiveness of the anthracycline anticancer drug. The effectiveness of the anthracycline anticancer drug thus can be predicted based on the information related to the recurrence obtained by the diagnosis support device.
[0259] In an effectiveness prediction device, a threshold value for predicting effectiveness (threshold value defined based on the recurrence rate obtained from the patients after being administered with anthracycline anticancer drug) may be stored in advance as a set value. Such effectiveness prediction device merely needs to be configured to calculate the recurrence rate, similar to the diagnosis support device of the first embodiment. The effectiveness prediction device also merely needs to be configured to predict the effectiveness of the anthracycline anticancer drug in the cancer patient to be examined by comparing the calculated recurrence rate and the threshold value. Specifically, the value of the recurrence rate and the threshold value are compared, and determination is made as “low effectiveness” if the value of the recurrence rate is greater than or equal to the threshold value, and determination is made as “high effectiveness” if the value of the recurrence rate is smaller than the threshold value.
[0260] The effectiveness prediction device is configured to display the prediction result of effectiveness as result of analysis on the display screen for outputting (displaying) the result of analysis. An example of such display screen is shown in FIG. 25 . In the display screen shown in FIG. 25 , ID number, age, and the like of the cancer patient to be examined are displayed on the display region 601 . The information display region 602 also displays data on cancer patient to be examined, that is, the CDK1 specific activity and the CDK2 specific activity obtained from the malignant tumor of the cancer patient to be examined. A graph having the CDK1 specific activity and the CDK2 specific activity as two axes is displayed in the distribution diagram display region 603 . The result of the calculated recurrence rate is displayed on the information display region 604 . The determination result of effectiveness is displayed as information related to the effectiveness of the anthracycline anticancer drug in the cancer patient to be examined on the information display region 605 .
[0261] With regards to other configurations and processes, the configurations and processes similar to the diagnosis support device of the first embodiment can be applied to the effectiveness prediction device.
[0262] In the effectiveness prediction device, the effectiveness is predicted (determined) based on the calculated recurrence rate, but is not limited thereto. In the second to the fourth embodiments, the sample data extraction range is determined by comparing the CDK1 specific activity and the CDK2 specific activity of the data on cancer patient to be examined with the reference value set in advance. The reference value is the reference value capable of dividing the cancer patients administered with the anthracycline anticancer drug into at least two groups of different recurrence risks, and thus the effectiveness of the anthracycline anticancer drug in the cancer patient to be examined can be predicted by determining to which group divided by the reference value the data on cancer patient to be examined belongs.
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A device for supporting a diagnosis of a cancer which provides information useful to decide whether or not an anthracycline anticancer drug should be administered to a cancer patient to be examined is disclosed. Concretely, the device is composed to be able to acquire an activity and an expression of two cyclin dependent kinases (CDK) from a malignant tumor of a cancer patient to be examined, and to acquire a CDK parameters from both of two CDKs. Furthermore the device determines sample data comprising predetermined CDK parameter, and display information of determined sample data. According to the above component, user is easily able to know whether or not a cancer of a cancer patient, whose tumor is similar to the tumor of the cancer patient to be examined, has been recurred in spite of an administration of an anthracycline anticancer drug.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 62/036,156, filed Aug. 12, 2014, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] The subject matter disclosed herein relates to load-management systems in a vertical take-off and landing (VTOL) aircraft, and to a system and method for determining external sling length for cargo during automated external sling load delivery via an autonomous VTOL aircraft.
DESCRIPTION OF RELATED ART
[0003] Typically, a utility VTOL aircraft's ability to carry cargo is one of its most important features. The VTOL aircraft, e.g., a helicopter, can be typically equipped to carry large, long, or oddly shaped cargo on an external sling provided that the cargo is within the lifting capacity of the aircraft. A significant advantage associated with this lifting capability is that a load may be picked up from or delivered to locations where access by other forms of transportation is difficult or impossible. Additionally, the systems do not require the VTOL aircraft to land to deliver or pick up the cargo.
[0004] In external cargo operations, picking up, or delivering cargo requires three to four people to maneuver the aircraft: a pilot and/or co-pilot, a crew chief (if cabin equipped), and a load master (on the ground) maneuver the aircraft into place for attaching the sling to external cargo during picking up and/or providing directions to avoid obstacles during pickup/delivery of the cargo. Prior and during the pickup/delivery, the crew establishes certain parameters of the external load required by the pilot(s) for flight and subsequent pickup/delivery. An autonomous VTOL aircraft can include manned and unmanned aircraft. In an unmanned VTOL aircraft, there is no flight crew to coordinate these maneuvers for delivery and pick-up of loads. So, the three to four people in a manned aircraft may not be available in an unmanned aircraft to maneuver the aircraft and the load and provide necessary parameters. Even in an autonomous manned vehicle, additional information for maneuvering the aircraft can provide robust operational capability in the field. Therefore, there is a need for a system that can provide the autonomous VTOL aircraft with necessary parameters in relation to an external sling load for automated delivery and pick up of loads.
BRIEF SUMMARY
[0005] According to an embodiment of the invention, a method for determining length of load sling assembly in an aircraft, includes receiving, with a processor, information via one or more sensors regarding a load length during a delivery and descent state, the load length comprising length of a load sling assembly and a load height; controlling, with the processor, a minimum altitude of operation of the aircraft that ensures that the load does not touch the ground or obstacles during one or more of a flight plan, during decent, or during delivery; determining, with the processor, when a load has touched a ground in response to the receiving of the load length information; and releasing, with the processor, the load from the load sling assembly when the processor determines that the load has touched the ground.
[0006] According to another embodiment of the invention, a system for determining length of load sling assembly in an aircraft with one or more sensors coupled to the aircraft; the load sling assembly including a sling coupled to an attachment device and a load; and memory having instructions stored thereon that, when executed by the processor, cause the system to receive information regarding a load length during a delivery and descent state, the load length comprising a length of the load sling assembly and a load height; control a minimum altitude of operation of the aircraft that ensures that the load does not touch the ground or obstacles during one or more of a flight plan, during decent, or during delivery; determine when a load has touched a ground in response to the receiving of the load length information; and release the load from the load sling assembly when the processor determines that the load has touched the ground.
[0007] In addition to one or more of the features described above, or as an alternative, further embodiments could include determining the load height during an initial descent state.
[0008] In addition to one or more of the features described above, or as an alternative, further embodiments could include determining of the load height during the initial descent state further comprises determining the load height from one or more of a distance of the aircraft to each of the load, a pendant, a bucket height factor, and the ground.
[0009] In addition to one or more of the features described above, or as an alternative, further embodiments could include receiving information regarding the load height during a lift state.
[0010] In addition to one or more of the features described above, or as an alternative, further embodiments could include determining the load height as a function of a distance of the aircraft to the load and a distance of the aircraft to the ground.
[0011] In addition to one or more of the features described above, or as an alternative, further embodiments could include determining the load length through successive iterations of the difference between the distance between the aircraft to each of the load and the pendant.
[0012] In addition to one or more of the features described above, or as an alternative, further embodiments could include navigating the load to a landing site in response to receiving the load length information during the delivery and descent state.
[0013] Technical function of various embodiments includes determining the sling load length from one or more sensors on board a VTOL aircraft. Sensors provide a flight control system with information when the load is off the ground prior to executing a departure, that adequate ground clearance is provided throughout the mission so that the load does not hit any obstacles in the VTOL aircraft's path, and when the load is placed on the ground and can be released.
[0014] Other aspects, features, and techniques of the invention will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like elements are numbered alike in the several FIGURES:
[0016] FIG. 1 illustrates a schematic block diagram of a system in accordance with an embodiment of the invention;
[0017] FIG. 2 is a view of a VTOL aircraft that is shown in a descent state for initial pick-up of an external cargo in accordance with an embodiment of the invention;
[0018] FIG. 3 is a view of a VTOL aircraft that is shown in a lift state in accordance with an embodiment of the invention; and
[0019] FIG. 4 is a view of a VTOL aircraft that is show in a delivery and descent state in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Embodiments of a flight control system coupled to a suspension system of an autonomous VTOL aircraft or an unmanned VTOL aircraft includes one or more algorithms for determining a length of an external cargo sling and total load length with exemplary embodiments are discussed below in detail. The suspension system includes an external load sling with a pendant that can be selectively coupled to an external load at the bottom of the VTOL aircraft and receives information related to sensors and load in order to determine load height, load length, and cargo sling length for automated external sling load delivery for the autonomous VTOL aircraft. The information can be used to provide a flight control system with critical information for mission management safety margins, flight dynamics, and the like.
[0021] Referring to the drawings, FIG. 1 illustrates a schematic block diagram of a control system 100 on board an autonomous vertical take-off and landing (VTOL) aircraft 200 (hereinafter “VTOL aircraft 200 ”) ( FIGS. 2-4 ) in accordance with an exemplary embodiment. VTOL aircraft 200 can include a manned autonomous vehicle as well as an unmanned autonomous vehicle. As control system 100 is implemented on board VTOL aircraft 200 ( FIGS. 2-4 ) for determining sling length and load in relation to aircraft, FIGS. 2-4 are also being referenced in this description of control system 100 of FIG. 1 .
[0022] As illustrated, control system 100 includes a Flight Control System 102 (“FCS 102 ”) that executes instructions for implementing a control algorithm 104 that determines, in some non-limiting examples, load height, load length, and cargo sling length and maneuvers VTOL aircraft 200 for automated external sling load or cargo delivery for VTOL aircraft 200 . FCS 102 may receive real-time information acquired from sensors 106 that may be used to acquire sensor information related to VTOL aircraft 200 and a load on the ground. Sensors 106 can include LIght Detection And Ranging (LIDAR), LAser Detection And Ranging (LADAR), Radio Detection And Ranging (RADAR) altimeter, gyroscopes, accelerometers, positional sensors, an inertial measurement unit (IMU), or the like. Sensor information data received by FCS 102 can include a current geographical location of VTOL aircraft 200 , height on top of a load above ground level, distance of VTOL aircraft 200 to a pendent at an end of a sling, infrared cameras, visual based cameras, or radar type sensors with focused beams on the ground and loads for information on the load with respect to VTOL aircraft 200 , and data related to mapped geographical terrain. Sensor information can be used to provide information on an external load as well as for path planning of VTOL aircraft 200 . Additional navigation systems on VTOL aircraft 200 can include GPS or the like to provide enhanced positional awareness for VTOL aircraft 200 . Flight control system 102 may also receive real-time force information from one or more sensor devices 108 attached to sling assembly such as, e.g., strain gauge load cells embedded in pendants at an end of a cargo sling assembly 206 to provide sensor information related to weight on pendant and load on pendant.
[0023] FCS 102 includes a memory 112 that communicates with a processor 114 . Memory 112 may store control algorithm 104 as executable instructions that are executed by processor 114 . The executable instructions may be stored or organized in any manner and at any level of abstraction, such as in connection with the execution of control algorithm 104 . Processor 114 may be any type of processor such as a central processing unit (CPU) or a graphics processing unit (GPU), including a general purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like. Also, in embodiments, memory 112 may include random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic, or any other computer readable medium onto which is stored control algorithm 104 described below.
[0024] Control system 100 may include a database 116 . Database 116 may be used to store information acquired by VTOL aircraft 200 during flight maneuvers including information acquired by one or more sensors related to a condition of cargo and its relation to VTOL aircraft 200 during maneuvers. Database 116 may also store information on real time data acquired by sensors 106 , 108 . The data stored in database 116 may be based on one or more other algorithms or processes for implementing control algorithm 104 . For example, in some embodiments data stored in database 116 may be a result of processor 114 having subjected the received data to one or more filtration processes. Database 116 may be used for any number of reasons. For example, Database 116 may be used to temporarily or permanently store data, to provide a record or log of the data stored therein for subsequent examination or analysis, etc. In some embodiments, Database 116 may store a relationship between data, such as one or more links between data or sets of data acquired on board VTOL aircraft 200 .
[0025] Control system 100 may provide one or more controls, such as vehicle controls 118 . Vehicle controls 118 may provide directives based on, e.g., navigating, and/or maneuvering VTOL aircraft 200 during a plurality of flight states such as, e.g., initial descent state for picking-up cargo, lift state after cargo has been acquired, and delivery descent state for delivering cargo to a location and releasing the cargo hook. The directives may be presented on one or more input/output (I/O) devices 110 . I I/O devices 110 may include a display device or screen, audio speakers, a graphical user interface (GUI), etc. For a manned VTOL aircraft 200 , I/O 110 devices can be located on the VTOL aircraft 200 while for an unmanned VTOL aircraft 200 , I/O devices 110 may be remotely located from VTOL aircraft 200 , for example, on the ground. In some embodiments, the I/O devices 110 may be used to enter or adjust a linking between data or sets of data. It is to be appreciated that the system 100 is illustrative. In some embodiments, additional components or entities not shown in FIG. 1 may be included. In some embodiments, one or more of the components or entities may be optional.
[0026] FIGS. 2-4 illustrate an exemplary view of VTOL aircraft 200 for implementing various embodiments described herein. VTOL aircraft 200 includes an airframe 202 with a main rotor system 204 and a tail rotor system 220 . Main rotor system 204 provides thrust while tail-rotor system provides anti-torque to counteract rotor torque on airframe 202 created by main rotor 204 . Although a particular configuration of VTOL aircraft 200 is illustrated and described in the disclosed embodiments, it will be appreciated that other configurations and/or machines include autonomous and semi-autonomous aircraft that may operate over land or water including fixed-wing aircraft, tilt rotor, and rotary-wing aircraft may also benefit from embodiments disclosed.
[0027] Referring to FIG. 2 , shown is VTOL aircraft 200 during an initial descent state for picking-up cargo or load 208 in accordance with an embodiment of the invention. VTOL aircraft 200 can include one or more devices 210 - 212 associated with sensors 106 and 108 that provide information to FCS 102 , related to aircraft state, distance from aircraft to top of load C 1 , distance from aircraft to pendant C 2 , and distance from aircraft to ground C 3 . As such, FIG. 1 is also referenced in the description of FIG. 2 . In an embodiment, VTOL aircraft 200 can include additional sensors associated with devices 210 - 212 in order to provide additional flight information and load information for processing by FCS 102 .
[0028] In an initial descent state, VTOL aircraft 200 can descend to a point to approach load 208 with a suspension system attached. Suspension system can include, for example, a cable or sling having a defined or undefined length of cable with an attachment device at a distal end of sling (collectively referred to as “sling assembly 206 ”) that defines a sling length. In embodiments, attachment device can be a pendant or other similar device for coupling to top of load 208 with a nominal height, a set predefined value, or an unknown value. In an embodiment, sling length can include an additional chain or device 214 that represents a bucket height factor (BF) (shown in FIGS. 3-4 ). As VTOL aircraft 200 descends, sensors 106 and 108 associated with device 210 - 212 provide information to FCS 102 for implementing control algorithm 104 , by processor 114 , in order to determine load height (LH) and minimum altitude (Min Alt) for VTOL aircraft 200 for implementation during descent state or for a load release in a delivery and descent state. Load height (LH) and Minimum altitude (Min Alt) can be determined according to Equations (1) and (2). Device 210 can provide C 1 (i.e., distance from aircraft to top of load 208 ), C 2 (i.e., distance from aircraft to pendant), while device 212 can provide C 3 (distance from aircraft to ground). Control algorithm 104 uses C 1 , C 2 , and C 3 to determine load height (LH), load length (LL), and a bucket height factor (BF). BF represents an offset that includes a length of additional chain or device 214 (See FIG. 3 ) that may be coupled to load 208 for lifting load 208 by pendant. Chain/device 214 adds additional length to Equation (1) under tension as shown in FIG. 3 .
[0000] Load Height=for [ n 1−∞ , if((( C 2 n +BF )= C 1 n ), C 3 −C 1, “ ”), until Load height≠“ ”] (1)
[0000] Min Altitude=Load Height+Safety Margin (2)
[0029] Where:
[0030] Min Altitude=Minimum altitude for aircraft during load release;
[0031] Load Height=Height of top of load Above Ground Level (AGL);
[0032] C1=Distance from aircraft to top of load;
[0033] C2=Distance from aircraft to Pendant;
[0034] C3=Distance from aircraft to ground; and
[0035] BF=Bucket height Factor.
[0036] According to Equation 1, LH is iteratively processed until C 1 equals C 2 and BF. BF may be predetermined or unknown upon which Equation (1) can include an open loop. When C 2 and BF equals C 1 and is not varying in time, then cable sling assembly 206 is slack, and LH equals a difference between C 3 and C 1 . If LH is initially calculated, and C 1 later begins to negatively separate or deviate from C 2 and BF, then sling assembly 206 may have missed the load or does not have correct tension and the load height (LH) measurement during the descent state may be rejected requiring recapture. Additionally, once LL has been determined from Equation (1), the FCS 102 can establish a minimum altitude for operations with a predetermined or open loop safety margin. Minimum altitude for operations includes safe altitudes of flight for VTOL aircraft 200 to ensure that the load 208 does not strike the ground or obstacles during a flight plan or prematurely during decent/delivery.
[0037] FIG. 3 illustrates an exemplary view of a VTOL aircraft 200 that is shown during a lift state according to an embodiment of the invention. In the lift state, VTOL aircraft 200 has made an attachment to load 208 through sling assembly 206 and additional chain/device 214 and VTOL aircraft 200 starts lifting up. With continued reference to FIG. 1 , as VTOL aircraft 200 ascends or lifts, sensor information is received from sensors 106 and 108 by FCS 102 in order to determine LL as well as a stack-up of various lengths for linkages from bottom of VTOL aircraft 200 to ground according to Equations (3) and (4). Sensor information can include weight on pendant and load on pendant. The stack-up of information is provided to FCS 102 in order to identify safe limits when the load should hit the ground from an elevated position so that during flight, a final delivery, and descent state, VTOL aircraft 200 does not descend below an unsafe height.
[0000] Load Length=for [ n 1−∞ , if((( C 1 n+ −C 2 n+1 )−( C 1 n −C 2 n )=0, C 3, “ ”), until Load height≠“ ”] (3)
[0000] Load Height= C 3− C 1 (4)
[0038] Where:
[0039] Load Height=Height of top of load Above Ground Level (AGL);
[0040] C1=Distance from aircraft to top of load;
[0041] C2=Distance from aircraft to Pendant; and
[0042] C3=Distance from aircraft to ground.
[0043] In embodiments, C 1 and C 2 can be the same value such as, for example, when an additional chain/device 214 is not connected to load 208 . In an absence of chain 214 , BF (from Equation (1)) is equal to zero. However, with a chain/device 214 , additional length of chain/device 214 provides a difference between C 1 and C 2 . At this time, lengths for cable sling assembly 206 and BF (sling length), LH, and LL are calculated and stored in control system 200 .
[0044] FIG. 4 illustrates an exemplary view of a VTOL aircraft 200 that is shown during a delivery and descent state according to an embodiment of the invention. With continued reference to FIG. 1 , in a delivery and descent state, FCS 102 can use LL that was determined from the lift state ( FIG. 3 ) to identify safe zones for delivering cargo 208 , path planning so as to avoid obstacles that may contact load during flight, and pilot operations. As VTOL aircraft 200 descends, sensors 106 , 108 receive and provide information to FCS 102 for implementing control algorithm 104 by processor 114 in order to determine LH and minimum altitude for VTOL aircraft 200 during load release according to Equation (5). Control algorithm 104 iteratively processes Equation (5) as VTOL aircraft 200 descends until the C 1 current reading diverges from the C 1 previous reading whereby LL is then equal to C 3 and the load 208 is safely on the ground.
[0000] Load Length=for [ n 1−∞ , if(( C 1 n+1 −C 1 n )=0, C 3, “ ”)] (5)
[0045] Where:
[0046] C1=Distance from aircraft to top of load; and
[0047] C3=Distance from aircraft to ground.
[0048] In another embodiment, sensor information obtained during an initial descent state or a lift state is not available for FCS 102 , for example, if load 208 was a pre-prepared load. In this instance, sensor information can be acquired by sensors 106 , 108 during a delivery and descent state. For example, sensors can provide information as to when load 208 has hit the ground. For example, sensor information can provide information to FCS 102 regarding when cable assembly 206 becomes slack. FCS 102 can determine if the load is on the ground based on converging values between C 1 and C 3 . Upon receiving sensor information that confirms that load 208 is on the ground, FCS 102 can provide a signal to pendant in order to release load 208 or, alternatively, release cable assembly 206 thereby releasing the load 208 .
[0049] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. While the description of the present invention has been presented for purposes of illustration and description, it is not intended to be exhaustive or limited to the invention in the form disclosed. For instance, aspects of the invention are not limited to propeller blades for aircraft, and can be used in wind turbines and other systems with rotary elements. Many modifications, variations, alterations, substitutions or equivalent arrangement not hereto described will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. Additionally, while the various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
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A system and method for determining length of load sling assembly in an aircraft, includes receiving, with a processor, information via one or more sensors regarding a load length during a delivery and descent state, the load length comprising length of a load sling assembly and a load height; controlling, with the processor, a minimum altitude of operation of the aircraft that ensures that the load does not touch the ground or obstacles during one or more of a flight plan, during decent, or during delivery; determining, with the processor, when a load has touched a ground in response to the receiving of the load length information; and releasing, with the processor, the load from the load sling assembly when the processor determines that the load has touched the ground.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a Division of application Ser. No. 08/929,057, filed on Sep. 15, 1997, and now U.S. Pat. No. 6,063,701.
BACKGROUND OF THE INVENTION
The present invention relates to a device for arranging conductive particles in a preselected pattern for the connection of electric circuit boards or electric parts. More particularly, the present invention is concerned with a device for surely and efficiently transferring solder bumps to the electrode pads of a semiconductor chip or the leads of a TAB (Tape Automated Bonding) tape, and a conductive particle transferring method using the same.
It is a common practice with, e.g., LSI (Large Scale Integration) circuits and LCDs (Liquid Crystal Displays) to connect electric circuit boards by using conductive particles.
After electric conduction has been set up between the circuit boards by the conductive particles, the circuit boards are fixed by an adhesive. Specifically, after the conductive particles have been arranged on either one of the circuit boards, an adhesive is applied and then set after the alignment of electrodes. To arrange the particles on the circuit board, they may be simply sprayed, as taught in, e.g., Japanese Patent Laid-Open Publication Nos. 2-23623 and 3-289070.
With the spraying scheme, however it is difficult to control the positions and the number of the particles on the electrodes. Particularly, when the electrodes are arranged at a fine pitch, the particles are apt to short the electrodes or to render the connection resistance irregular due to the irregular number thereof on the electrodes. Although the particles may be arranged on the electrodes while having their positions controlled, such an approach needs a sophisticated control system.
For the electrical connection of the electrode pads of a semiconductor chip and outside leads, a wire bonding system, a TAB system and a flip-chip bonding system are typical systems available at the present stage of development. The TAB system and flip-chip bonding system each uses conductive particles in the form of solder bumps (simply bumps hereinafter) for electrical connection. Specifically, in the TAB system, bumps intervene between the electrode pads of a semiconductor chip and the film-like leads of a TAB tape. In the flip-chip bonding system, bumps intervene between the electrode pads of a semiconductor chip and the leads of a circuit board.
Today, the following methods are extensively used to form bumps. In one method, the exposed portions of electrode pads provided on a semiconductor chip are covered with barrier metal. After a solder film pattern has been formed on the barrier metal, reflow and annealing are effected in order to cause the solder film to shrink on the barrier metal due to its own surface tension. In another method, bumps are formed on the electrode pads one by one by a wire bonder. Recently, a transfer bump method has been proposed which is advantageous over the above direct methods from the step and cost standpoint. The transfer bump method forms bumps on an exclusive transfer substrate by an electrolytic plating scheme. The bumps on the transfer substrate are aligned with the leads of a TAB tape in the TAB system or with the electrode pads of a semiconductor chip in the flip-chip bonding system. Then, the bumps are bonded by heat and transferred to the leads or the electrode pads. It is not too much to say that the the transfer bump method has broadened the applicable range of the TAB system.
However, the problem with the bumps formed by the electrolytic plating scheme is that they have flat surfaces and cannot be evenly transferred unless they have exactly the same height. In light of this, Japanese Patent Publication No. 7-27929 discloses a device capable of arranging spherical bumps on a transfer substrate. However, while the electrolytic plating scheme is capable of defining positions for forming the bumps beforehand, the spherical bumps are produced at random. Therefore, the key to the spherical bump scheme is how efficiently the bumps can be arranged in preselected positions. For the efficient arrangement of the bumps, the above document teaches that the diameter of the spherical bumps is strictly controlled. However, because the diameter of the bumps decreases with a decrease in the pitch of the electrode pads or that of the leads, it is extremely difficult to provide the bumps with the same diameter. As a result, the accuracy required of the flatness of the leads of a TAB tape, the flatness of a bonding tool and the parallelism of a transfer substrate and a TAB tape increases. The adjustment of such factors will become more difficult in the future in parallel with the progress of dense mounting.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a simple, low cost device capable of arranging conductive particles adequately.
It is another object of the present invention to provide a method capable of transferring conductive particles to a semiconductor chip, TAB tape or intermediate transfer member more surely and easily without increasing accuracy required of a device for practicing it.
In accordance with the present invention, a device for arranging conductive particles for connecting electric circuit boards includes a mask formed with openings in a preselected pattern for arranging the conductive particles. A squeegee is spaced from the mask by a preselected distance and movable over the mask in a preselected direction for filling the conductive particles in the openings of the mask. A stage is positioned below the mask for holding the conductive particles filled in the openings of the mask. A vacuum suction mechanism is positioned below the stage for sucking, via the stage, the conductive particles being moved on the mask by the squeegee into the openings of the mask.
Further, in accordance with the present invention, a device for arranging conductive particles includes a feeding section for feeding the conductive particles. A stage is implemented as a porous flat plate having opposite major surface. One of the opposite major surfaces expected t o arrange the conductive particles is implemented as fine irregular surface for restricting the movement of the conductive particles. A mask is formed with openings in a preselected pattern for defining an arrangement of the conductive particles on the stage. A sucking mechanism sucks the conductive particles via the other major surface of the stage to thereby retain the conductive particles on the one major surface of the stage. A drive source is drivably connected to at least one of the stage and mask for selectively moving the one major surface of the stage and a major surface of the mask toward or away from each other.
Moreover, in accordance with the present invention, a method of transferring conductive particles includes the step of positioning a stage comprising a porous flat plate having one of opposite major surfaces thereof expected to arrange the conductive particles implemented as a fine irregular surface for restricting the movement of the conductive particles and a mask formed with openings in a preselected pattern for defining an arrangement of the conductive particles on the stage close to each other and parallel or substantially parallel to each other. In this condition, the conductive particles are from above the mask to thereby cause the openings of the mask to trap the conductive particles. Then, excess conductive particles other than the conductive particles trapped in the openings are removed from the mask. Subsequently, the mask and stage are separated from each other. Finally, the conductive particles arranged on the stage are transferred to another surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings in which:
FIG. 1 is a sectional side elevation showing a first embodiment of the conductive particle arranging device in accordance with the present invention;
FIGS. 2-7 are sectional side elevations each showing a particular modification of a squeegee included in the first embodiment;
FIG. 8 is a sectional side elevation showing a modification of a mask also included in the first embodiment;
FIG. 9 is a sectional side elevation showing a modification of a pedestal and stage further included in the first embodiment;
FIG. 10 is a section showing a conventional conductive particle arranging device;
FIG. 11 is a section showing Example 1 of a second embodiment of the present invention;
FIGS. 12-17 are sections each showing Example 2 of the second embodiment in a particular condition;
FIG. 18 is a section showing Example 3 of the second embodiment;
FIGS. 19 and 20 are sections each showing Example 4 of the second embodiment in a particular condition;
FIG. 21 is a section showing Example 5 of the second embodiment;
FIGS. 22 and 23 are sections each sowing Example 5 in a particular condition;
FIG. 24 is a section showing Example 6 of the second embodiment;
FIGS. 25-28 are sections each showing Example 6 in a particular condition; and
FIG. 29 is a section showing Example 7 of the second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will b e described hereinafter.
1st Embodiment
This embodiment relates to a conductive particle arranging device applicable to the bump forming step stated earlier. As shown in FIG. 1, the device, generally 10 , includes a base 12 on which a guide rail 14 is mounted. A slider 16 is slidably mounted on the guide rail 14 and moved in the right-and-left direction, as seen in FIG. 1, by an air cylinder, not shown. A stage 18 is mounted on the slider 14 and shiftable up and down over a distance of about 10 mm by being driven by, e.g., an air cylinder.
A pedestal 20 is mounted on the stage 18 and implemented as a box-like or hollow cylindrical top-open member. The pedestal 20 has a bore 20 a fluidly communicated to a vacuum pump, not shown, via a passageway 20 b . A stage 22 is mounted on the pedestal 20 , closing the open top of the pedestal 20 . The stage 22 is implemented by a sintered ceramic body. The pedestal 20 carrying the stage 22 thereon has its bore 20 a evacuated by the vacuum pump via the passageway 20 b.
A mask 24 is held on and in contact with the top of the stage 22 . The mask 24 is implemented as a metal mask by way of example and formed with openings, not shown, in a preselected pattern for arranging conductive particles. If conductive particles to be arranged by the device 10 have a diameter of, e.g., 40 μm, then the above openings each has a diameter of 50 μm and a depth of 40 μm. A frame 22 a retains the peripheral portion of the mask 22 while a guide frame 26 guides and holds the peripheral portion of the mask 22 . The mask 24 with the openings is mounted on the stage 22 which is, in turn, mounted on the pedestal 20 , as stated above. Therefore, when the bore 20 a of the pedestal 20 is evacuated, vacuum is developed in the openings of the mask 24 via the stage 22 .
A frame 30 is supported by posts 28 above the mask 24 . Sliders 32 and 34 are mounted on the frame 30 and driven horizontally by an air cylinder or a stepping motor, not shown, in directions perpendicular to each other. A pair of squeegees 38 and 40 are affixed to the slider 34 facing the mask 24 via a jig 36 . The jig 36 is made up of a Z axis stage implementing adjustment in the vertical direction (Z direction), as seen in FIG. 1, and a goniometer implementing the adjustment of the angles of the squeegees 38 and 40 , although not shown specifically.
The squeegees 38 and 40 are positioned above and at a preselected distance from the mask 24 . When the sliders 32 and 34 are moved in the horizontal direction, the slider 34 moves the squeegees 38 and 40 in the horizontal direction. Conductive particles are fed to the mask 24 via the gap between the squeegees 38 and 40 .
The device 10 having the above construction will be operated as follows. Initially, the squeegees 38 and 40 are located at their initial position or home position defined at the right-hand side or the left-hand side of the openings of the mask 24 . Conductive particles are present between the squeegees 38 and 40 . The stage 18 is held in its elevated position, maintaining the stage 22 in contact with the mask 24 . The bore 20 a of the pedestal 20 is evacuated by the vacuum pump.
In the above condition, the squeegees 38 and 40 are moved over the openings of the mask 24 at the same time by the sliders 32 and 34 . As a result, the squeegees 38 and 40 move away from the home position while sequentially filling the openings of the mask 24 with the conductive particles. Because the bore 20 a of the pedestal 20 is evacuated, air is sucked out of the openings of the mask 24 via the stage 22 .
Consequently, the particles fed to the mask 24 are surely introduced into and held in the openings of the mask 24 .
When the movement of the squeegees 38 and 40 ends, the evacuation of the bore 20 a is interrupted while the stage 18 is lowered. As a result, the mask 24 and stage 22 are separated from each other. When the slider 16 is moved along the guide rail 14 , the conductive particles have been adequately arranged on the stage 22 in the desired pattern.
As shown in FIG. 2, the illustrative embodiment allows the distance between the mask 24 and the squeegees 38 and 40 to be smaller than the diameter of a conductive particle 42 . Specifically, in the illustrative embodiment, the mask 24 and squeegees 38 and 40 (only the squeegee 38 is shown) are spaced from the mask 24 by a distance a smaller than the diameter of the particle 42 . The distance a should preferably be one-half to one-fourth of the diameter of the particle 42 . In such a configuration, the particle 42 is prevented from escaping via the gap between the mask 24 and the squeegees 38 and 40 . This allows the particle 42 to be surely filled in the opening of the mask 24 and frees the mask 24 from wear or breakage.
As shown in FIG. 3, the thickness of the squeegees 38 and 40 (only the squeegee 38 is shown) may be reduced below the diameter of the particle 42 . Specifically, in the illustrative embodiment, each of the squeegees 38 and 40 has at least its lower edge provided with a thickness smaller than the diameter of the particle 42 . With this configuration, the squeegees 38 and 40 can move the particle 42 smoothly on and along the mask 24 .
More specifically, assume a squeegee 38 a shown in FIG. 4 and having a thickness greater than the diameter of the particle 42 . Then, it is likely that the particle 42 gets between the squeegee 38 a and the mask 24 and cannot smoothly move on the mask 24 . By contrast, the squeegee 38 shown in FIG. 3 allows the particle 42 to easily slip away upward and smoothly move on the mask 24 . Therefore, even when the particle 42 is implemented as a resin particle plated with metal, it can smoothly move on the mask 24 and adequately enters the opening of the mask 24 without being damaged.
As shown in FIG. 5, the angle between each of the squeegees 38 and 40 (only the squeegee 38 is shown) and the mask 24 may be selected to be less than 30 degrees inclusive. The flat squeegee 38 is inclined relative to the mask 24 by an angle β of less than 30 degrees inclusive. This also allows the conductive particle 42 to easily slip away upward, i.e., prevents it from getting between the squeegee 38 and the mask 24 and being damaged thereby. Therefore, even when the particle 42 is implemented as a resin particle plated with metal, it can smoothly move on the mask 24 and adequately enter the opening of the mask 24 without being damaged.
As shown in FIGS. 6 and 7, projections 44 and 46 may be provided on the lower edge of each of the squeegees 38 and 40 (only the squeegee 38 is shown) facing the mask 24 , so that an adequate distance can be maintained between the squeegees and the mask 24 . In the illustrative embodiment, the projections 44 and 46 are positioned at opposite ends of the lower edge of each of the squeegees 38 and 40 . The projections 44 and 46 each has a height which is less than one-half of the diameter of the conductive particle 42 inclusive. Specifically, when the diameter of the particle 42 is 40 μm, resin beads whose diameter is 10 μm to 20 μm may be affixed to the above positions of the lower edge of the squeegee by, e.g., an adhesive.
When the squeegees 38 and 40 are moved above the mask 24 with their projections 48 and 40 contacting the mask 24 , a preselected distance is surely maintained between the squeegees 38 and 40 and the mask 24 . This is an economical, yet adequate, implementation for preventing the particle 42 from escaping and causing the mask 24 to wear.
As shown in FIG. 8, the mask 24 may be provided with a thickness smaller than the diameter of the particle 42 , but greater than one-half of the same. Specifically, the mask 24 is formed with a plurality of openings 24 a . In the illustrative embodiment, the thickness of the mask 24 is selected to be smaller than the diameter of the particle 42 , but greater than one-half of the same. Therefore, when such particles 42 are introduced into the openings 24 a of the mask 24 laid on the stage 22 , the particles 42 rest on the top of the stage 22 . In this condition, less than one-half of each particle 42 protrudes from the top of the mask 24 . The particles 42 received in the openings 24 a of the mask 24 are delivered to the next step. In the next step, a transfer head, not shown, is lowered onto the mask 24 with the result that the particles 42 each protruding from the top of the mask 24 are transferred to the head.
With the configuration shown in FIG. 8, it is possible to deliver the mask 24 and stage 22 to the next step together, i.e., without lowering the stage 18 in order to separate the mask 24 and stage 22 . This reduces the number of steps of the device 10 and thereby promotes smooth and adequate arrangement of conductive particles.
FIG. 9 shows an alternative configuration of the pedestal 20 . As shown, the box-like or hollow cylindrical pedestal, labeled 48 , has a center bore 48 a and a peripheral bore 48 b surrounding the center bore 38 a , i.e., a double bore structure. The pedestal 48 is formed with a passageway 48 c communicated to the peripheral bore 48 b and a passageway, not shown, communicated to the center bore. The passageway 48 c and the other passageway, not shown, each is fuidly communicated to a respective vacuum pump, not shown, and evacuated thereby.
The stage 22 implemented as a sintered ceramic body is mounted on the top of the pedestal 48 , closing the center bore 48 b and peripheral bore 48 b . The mask 24 with the openings 24 a is mounted on the stage 22 , although not shown specifically. The conductive particles 42 are received in the openings 24 a of the mask 24 positioned above the center bore 48 a.
The center bore 48 a and peripheral bore 48 b of the pedestal 48 each is evacuated by the respective vacuum pump, as stated above. When the mask 24 having the particles 42 in its openings and the stage 22 are separated from each other, the pump communicated to the center bore 48 a above which the particles 42 are arranged is turned on while the other pump communicated to the peripheral bore 48 b is turned off. As a result, the particles 42 are prevented from being displaced. This can be done with miniature vacuum pumps at a low cost.
While the mask 24 has been shown and described a s comprising a metal mask, it may alternatively be implemented by, e.g., a polyimide film or similar resin film. With a polyimide film, it is possible to form the openings 24 a and therefore to arrange the particles 42 more accurately than with a metal mask when use is made of an excimer laser. It is to be noted that the openings 24 a formed by an excimer laser are tapered. From the accuracy standpoint, therefore, the particles 42 should preferably be directly transferred to a transfer head without the mask 24 being separated.
As stated above, the first embodiment achieves the following advantages.
(1) The device is capable of arranging conductive particles adequately with a simple, low cost structure.
(2) The particles are prevented from escaping via a gap between squeegees and a mask and causing the mask to wear or break.
(3) The particles are prevented from getting between the squeegees and the mask. Therefore, even when the particles are implemented as resin particles plated with metal, they are free from breakage.
(4) The squeegees are constantly spaced from the mask by a preselected distance during movement.
(5) The particles received in the openings of the mask can be directly transferred to a transfer head, so that the number of steps is reduced.
(6) When the stage is separated from the mask, only the portion around the particles is evacuated in order to prevent the particles from being displaced.
(7) The openings of the mask can be formed more accurately than the openings of a metal mask.
2nd Embodiment
To better understand this embodiment, reference will be made to FIG. 10 showing the conventional arrangement taught in Japanese Patent Publication No. 7-27929 mentioned earlier. The arrangement to be described addresses irregular transfer particular to the transfer bump method which forms conductive particles, i.e., bumps on an exclusive transfer substrate by electrolytic plating, and then transfers the bumps to the electrode pads of a semiconductor chip or the leads of a TAB tape. As shown in FIG. 10, a transfer substrate 50 is formed with through holes 53 . The holes 53 each has a smaller diameter than a bump bp at its bottom, but has a greater diameter than the bump bp at its top. With this configuration, the substrate 50 itself plays the role of a jig for positioning the bumps bp. The bottom side of the substrate 50 is depressurized in order to retain the bumps bp in the holes 53 by suction. Specifically, a bore 57 formed between the substrate 50 and a holder 56 supporting it is evacuated via an tubing 58 .
More specifically, the substrate 50 is implemented as a laminate of two flat sheets 51 and 52 . The sheets 51 and 52 are respectively formed with openings 54 having a diameter d 1 smaller than the diameter of the bumps bp, and openings 55 having a diameter d 2 greater than the same. The openings 54 and 55 are aligned with each other, constituting the through holes 53 . The holes 53 each has such a depth that less than one-half of the the bump bp, inclusive, introduced therein protrudes from the top of the substrate 50 . In practice, the thicknesses t 1 and t 2 of the sheets 51 and 52 , respectively, are optimized. The bumps bp arranged on the substrate 50 are transferred to, e.g., the leads of a TAB tape. Subsequently, the TAB tape is bonded to a semiconductor chip.
The bumps bp each is assigned to one electrode pad or one lead. Therefore, if the transfer of the bump to even one of several tens to a hundred and tens of electrodes or leads fails, the semiconductor chip is rejected. The conventional device transfers the bumps bp while retaining them in the holes 53 , so that the amount of protuberance of the bumps bp necessary for transfer is not achievable without resorting to strict control over the diameter of the bumps bp. However, the bumps decrease in diameter with a decrease in the pitch between nearby electrode pads or leads, making it more difficult to evenly control the diameter of the bumps bp.
The embodiment to be described realizes easy and sure transfer of bumps or conductive particles to a semiconductor chip or a TAB tape.
Basically, in this embodiment, the support for the conductive particles and the definition of a particle arrangement each is assigned to one of two independent members. The two members are moved toward each other for particle arrangement and then moved away from each other for particle transfer, so that the particles can be transferred in their fully exposed position. Assume that the particles are bumps. Then, this embodiment is capable of surely transferring the bumps with a high throughput without resorting to strict control over the height of the bumps, the flatness of the leads of a TAB tape, and the flatness of a bonding tool.
A conductive particle arranging device embodying the above concept needs a stage for laying conductive particles, a mask for defining a particle arrangement, and drive means drivably connected to at least one of the stage and mask. For the simplest construction and control, the drive means may be connected only to the stage in order to move the stage up and down relative to the mask fixed in place.
The particles can be fixed in place on the stage to a certain degree if the stage is implemented as a flat porous plate, and if suction is applied to the rear of the stage. In this embodiment, the stage is additionally provided with an irregular surface for arranging the particles, so that the particles can be prevented from being displaced when the stage and mask are separated from each other. The irregular surface may be implemented by fine lugs formed on the above surface or by a mesh whose mesh size is smaller than the diameter of the particles.
The fine lugs may be formed in either one of a regular pattern and an irregular or random pattern. A simple method for forming the irregular pattern consists in spraying a solution of thermosetting resin or that of ultraviolet (UV) curable resin onto the particle arranging surface of the stage, and curing the resulting fine drops by use of heat or UV rays. On the other hand, to form the regular pattern most simply, use may be made of the patterning of photoresist. With the patterning scheme, it is possible to freely select even the relation between the pitch of the fine lugs and that of the particles. If the pitch of the lugs is greater than the pitch of the particles, each particle will be trapped between two nearby lugs. If the former is smaller than the latter, each particle will be caught by a plurality of adjoining lugs.
The fine lugs or the mesh may at least partly be provided with tackiness to act on the particles. For this purpose, the lugs themselves may be formed of an adhesive material, or an adhesive material may be applied to the mesh. The adhesive material may be implemented by a silicone resin or an acryl resin. If desired, the mesh may be selectively provided with tackiness in its region corresponding to the region of the mask adjoining the openings, but not provided with it in the peripheral regions of the stage. This protects the mask from needless contamination.
In the illustrative embodiment, the drive means may include a tilting mechanism for causing the major surface of the stage and that of the mask to tilt by a small angle from their parallel position. When the stage and mask are separated from each other after the arrangement of the particles, the tilting mechanism reduces the sharp inflow of air and thereby prevents the particles from being displaced or flying about.
A bump arranging device with high practicability is achievable if the openings of the mask each is so sized as to trap a single particle, and if the particle is implemented as a conductive particle for forming a solder bump.
In the illustrative embodiment, two different particle arranging methods are available for the transfer of the particles to another surface, depending on the operating timing of the above tilting mechanism. A first method is t o slightly lower the degree of parallelism of the stage and mask at the time of arrangement of the particles. A second method is to arrange the particles while maintaining the stage and mask parallel to each other, slightly lower the degree of parallelism at least in the initial stage of separation of the stage and mask, and then restore the original parallelism when the danger of the sharp inflow of air has decreased. In any case, when the drive means is connected to the stage, the stage will be caused to tilt relative to the horizontal mask.
It is to be noted that “another surface” to which the particles are to be transferred refers to a TAB tape having leads, a semiconductor chip having bare pad electrodes, or a n intermediate transfer member preceding the TAB tape or the semiconductor chip.
Examples of the second embodiment are as follows.
EXAMPLE 1
FIG. 11 shows a conductive particle arranging device including a stage having fine lugs formed by spraying and then curing a UV curable resin. As shown, the device, generally 60 , includes a movable stage 62 and a fixed mask 72 . The stage 62 is movable along a guide rail 64 . A bump arranging section 60 A and a bump transferring section 60 B are respectively arranged at one end (right-hand side as seen in FIG. 11) and the other end (left-hand-side as seen in FIG. 11) of the guide rail 64 . Drive means, not shown, moves the stage 62 back and forth between the two sections 60 A and 60 B in a direction indicated by an arrow C. As a result, the arrangement of bumps Bp on the stage 62 and the transfer of the bumps Bp to a transfer head 66 are effected alternately.
The bump arranging section 60 A is surrounded by a frame 68 whose one end is open in the form of a gate 68 a for the ingress and egress of the stage 62 . The mask 72 is supported by a mask holder 70 which is, in turn, supported by the frame 68 . The bumps Bp are fed from above the mask 72 via a piping 74 . A squeegee 76 collects the bumps Bp not arranged on the mask 72 , i.e., excess bumps Bp. A guide rail 78 allows the squeegee 76 to move therealong only in a direction indicated by an arrow A. The squeegee 76 is driven by drive means, not shown.
The mask 72 is implemented as an about 40 μm thick nickel sheet and formed with openings 72 a each being so sized as to trap a single bump Bp. The bumps Bp had a mean diameter of about 40 μm while the openings 72 a had a diameter of about 50 μm. In Example 1, the mask 72 is fixed in its horizontal position.
The gap between the squeegee 76 and the mask 72 is selected to be less than one-half of the diameter of the bumps Bp inclusive, i.e., less than 20 μm inclusive, so that the squeegee 76 can collect all the excess bumps Bp.
In the bump transferring section 60 B, the transfer head 66 includes optics 80 for exposure. A quartz window 82 coated with an adhesive paint is provided on the surface of the head 66 which will face the stage 62 . The optics 80 fixes the bumps Bp to the electrode pads of an LSI chip, not shown, by using a UV curable adhesive. For this purpose, the optics 80 includes a light source for feeding optical energy for the curing reaction of the adhesive, and an optical fiber for evenly guiding light issuing from the light source to the quartz window 82 .
The head 66 is movable up and down in a direction indicated by an arrow D in order to adhere the bumps Bp of the stage 62 to the quartz window 82 and then transfer the bumps Bp to the LSI chip, not shown, at another place. The stage 62 is formed of ceramics or similar porous material. A great number of fine lugs 84 each being about 10 μm high are formed on the surface of the stage 62 . The lugs 84 not only restrict the movement of the bumps Bp on the particle arranging surface of the stage 62 , but also prevent the particle arranging surface and mask 72 from closely contacting each other. The above specific height of the lugs 84 was selected in order to prevent two or more bumps Bp from gathering at a single position. In Example 1, the lugs 84 were formed by spraying a UV curable resin dissolved in a suitable solvent onto the stage 62 , and then curing the drops of the solution by UV radiation.
The stage 62 is supported by the stage holder 86 along its edges. A chamber 90 is formed between the rear of the stage 62 and the stage holder 86 and fluidly communicated to an evacuating unit 88 . In this configuration, the bumps Bp each being trapped in one opening 72 a of the mask 72 are restricted in position on or between the lugs 84 , and additionally restricted by suction acting from the rear of the stage 62 .
The stage holder 86 is fixed to an elevatable base 91 engaged with the guide rail 64 stated earlier. The base 90 is moved in the direction C while carrying the stage 62 thereon.
The base 91 is extendable in a direction indicated by an arrow B and allows the distance between the stage 62 and the mask 72 to be adjusted when they are conveyed to the bump arranging section 60 A. The amount of extension in the direction B does not have to be uniform over the entire stage 62 . For example, an actuator may be used to cause the base 91 to extend more at one end of the stage 62 than at the other end of the stage 62 . This allows the particle arranging surface of the state 62 to slightly tilt from horizontal in a direction E when the bumps Bp are arranged on the stage 62 or when the stage 62 carrying the bumps Bp is moved away from the mask 72 .
In the above configuration, the transfer of the bumps Bp is effected without regard to the mask 72 . Therefore, all the bumps Bp arranged on the stage 62 can be transferred to another surface without resorting to sophisticated control over the height of the bumps Bp, as measured from the surface of a substrate, and bump diameter.
EXAMPLE 2
In Example 2, the particle arranging device 60 was used to actually transfer the bumps Bp to the electrode pads of an LSI chip. The transfer will be described with reference to FIGS. 12-17.
First, as shown in FIG. 12, the mask 72 and stage 62 are positioned close to each other, and each is held in its horizontal position. The bumps Bp each is received in one of the openings 72 a . The bumps Bp are implemented as resin beads plated with Ni (nickel) and Au (gold) in a laminate structure. The excess bumps Bp not received in the openings 72 a are collected by the squeegee 76 moving back and forth in the direction A.
Subsequently, as shown in FIG. 13, the elevatable base 91 is operated to move the stage 62 away from the mask 72 . In the initial stage of the separation, the tilting movement stated earlier may be effected in order to prevent air from sharply flowing into the gap between the mask 72 and the stage 62 . This maintains the accurate arrangement of the bumps Bp. Thereafter, the stage 62 is lowered in the direction B to a level at which the stage 62 can be conveyed out of the bump arranging section 60 A. It is to be noted that the stage 62 can be restored to its horizontal position at the time when the influence of the stream of air has become negligible.
FIG. 14 shows a condition wherein the stage 62 is fully separated from the mask 72 , and the bumps Bp are arranged on the stage 62 . Because the fine lugs 84 are irregularly arranged on the stage 62 , some bumps Bp are trapped between nearby lugs 84 while the other bumps B rest on a plurality of nearby lugs 84 . Although the height above the stage surface slightly differs from one bump Bp to another bump Bp, the difference is only less than 10 μm.
Subsequently, the base 91 is moved in the direction C in order to convey the stage 62 out of the bump arranging section 60 B. Then, as shown in FIG. 15, the transfer head 66 was lowered in the direction D until the bumps Bp adhered to the surface of the quartz window 82 applied with the adhesive material. In Example 2, the bumps Bp existed on the stage 62 in their bare state. This, coupled with the fact that the adhesive material absorbed the difference in height between the bumps Bp and sufficiently contacted all the bumps Bp, allowed the bumps Bp to be shifted to the head 66 without exception.
As shown in FIG. 16, the head 66 was moved to a position above an LSI chip 92 in order to align the bumps Bp with the electrode pads 94 of the chip 92 . Then, the head 66 was lowered in the direction 66 . The surfaces of the electrode pads 94 are covered with UV curable adhesive layers 96 beforehand. After the bumps Bp on the head 66 contacted the adhesive layers 96 , UV rays hv were radiated from the optics 80 . The UV rays hv caused the adhesive layers 96 to set via the quartz window 82 . As a result, the bumps Bp were fixed to the electrode pads 94 as shown in FIG. 17 .
Finally, the head 66 is raised away from the chip 92 .
This is the end of the bump transfer procedure of Example 2.
EXAMPLE 3
In Example 3 , the stage 62 is slightly tilted from the horizontal at the time of arrangement of the bumps Bp thereon in order to protect the arrangement of the bumps Bp from a stream of air. Specifically, as shown in FIG. 18, the bumps Bp were arranged on the stage 62 inclined by an angle of θ from the horizontal via the base 91 . The angle θ is free to choose so long as the bumps Bp do not escape from the openings 72 a of the mask 72 . After the arrangement of the bumps Bp, the stage 62 and mask 72 may be separated from each other by the method described in relation to Example 2.
EXAMPLE 4
As shown in FIGS. 19 and 20, in this example, the fine lugs 84 on the stage 62 are replaced with fine lugs 84 a formed in a regular pattern by photolithography. Specifically, the lugs 84 a are implemented as a resist pattern formed by the selective exposure and development of a photoresist film provided on the stage 62 .
As shown in FIG. 19, when the pitch P 2b of the lugs 84 a is sufficiently smaller than the pitch P B of the bump Bp, the bumps Bp rest on the lugs 84 a without contacting the particle arranging surface of the stage 62 . As shown in FIG. 20, when the pitch P 2b is sufficiently greater than the pitch P B , the bumps Bp contact the particle arranging surface of the stage 62 between the adjacent lugs 84 b.
EXAMPLE 5
In this example, the fine lugs on the stage 62 are provided with tackiness. As shown in FIG. 21, the fine lugs are constituted by an adhesive resin buried layer 98 which may be formed by use of a silicone resin. A method of forming the layer 98 will be described with reference to FIGS. 22 and 23.
First, as shown in FIG. 22, conventional resist patterning was effected on the stage 62 in order to form a resist pattern 100 . Then, as shown in FIG. 23, the adhesive resin buried layer 98 was formed such that a silicone resin filled the spaces of the resist pattern 100 . After the setting of the silicone resin, the resist pattern 100 was removed by a peeling liquid. As a result, only the layer 98 was left on the stage 62 , as shown in FIG. 21 .
The fine lugs formed by the above procedure have tackiness themselves and retain the bumps Bp more positively than the fine lugs implemented by the previously stated UV curable resin. Therefore, even when a flow of air occurs at the time of separation of the stage 62 and mask 72 , the disturbance to the arrangement of the bumps Bp can be minimized. In addition, to obviate the flow of air, the tilting angle of the stage 62 can be increased.
EXAMPLE 6
In this example, the fine lugs with tackiness are not formed over the entire particle arranging surface of the stage 62 , but formed only in the region of the stage 62 adjoining the openings 72 a of the mask 72 . Specifically, as shown in FIG. 24, the fine lugs are constituted by an adhesive resin buried layer 98 b and a resist pattern 100 c . The layer 98 b is selectively formed in a region M adjoining the openings 72 a of the mask 72 . For the layer 98 b , use may be made of a silicone resin. The resist pattern 100 c surrounds the above region M and is formed of a conventional positive type photoresist material. With this configuration, it is possible to free the mask 72 from contamination when the mask 72 and stage 62 are brought into contact.
FIGS. 25-28 show a procedure for forming the fine lugs of this example by two consecutive photolithographic steps. First, as shown in FIG. 25, a positive type photoresist film 102 formed on the stage 62 was subjected to the first selective exposure via a photomask 104 . The photomask 104 is made up of a substrate 106 transparent for exposing light, and a Cr (chromium) film or similar light intercepting film pattern 108 formed on the substrate 106 . The pattern 108 defines a position for forming the layer 98 b (FIG. 27) in the region M. While the exposure is shown as being proximity exposure in FIG. 25, it may be contact exposure or projection exposure, if desired.
Subsequently, the exposed region of the photoresist film 102 was removed by the first development in order to form a resist pattern 100 b shown in FIG. 26 . Then, as shown in FIG. 27, the adhesive resin buried layer 98 b was formed such that the spaces of the resist pattern 100 b were filled with a silicone resin.
As shown in FIG. 28, after the setting of the above layer 98 b , the resist pattern 100 b on the stage 62 was subjected to the second selective exposure via a photomask 110 . The photomask 110 is also made up of a substrate 112 transparent for exposing light, and a Cr film or similar light intercepting film pattern 114 formed on the substrate 112 . The pattern 114 causes a new resist pattern 100 c shown in FIG. 28 to be formed in the peripheral region around the region M. At the same time, the pattern 114 defines an exposure area for causing the resist pattern 100 b existing in the region M to be removed.
After the second selective exposure, the second development was effected so as to produce the stage 62 shown in FIG. 24 . As shown, the stage 62 has two different kinds of fine lugs each being confined in a respective region.
EXAMPLE 7
In this example, the fine lugs for retaining the bumps Bp are replaced with a mesh 116 laid on the stage 62 . As shown in FIG. 29, the mesh 116 is laid on the stage 62 such that the bumps Bp trapped in the openings 72 a of the mask 72 are arranged on the mesh 116 . The mesh 116 is formed of, e.g., stainless steel. The mesh size of the mesh 116 is selected to be sufficiently smaller than the diameter of the bumps Bp, yet to surely retain the bumps Bp. In Example 7, the apertures of the mesh were about 20 μm.
The bumps Bp may be arranged on the stage 62 and then transferred by the previously stated procedure.
While this example maintains both the stage 62 and mask 72 horizontal at the time of arrangement of the bumps Bp, the stage 62 may be slightly tilted from the horizontal via the elevatable base 91 in the same manner as in Example 3. Further, when the stage 62 and mask 72 are separated from each other, the stage 62 may advantageously be lowered while being tilted, as in Example 1.
The illustrative embodiment is not limited to Examples 1-7 shown and described. For example, the bumps Bp arranged on the stage 62 and brought to the bump transferring section 60 B may be directly bonded to the leads of a TAB tape by a conventional bonding tool, i.e., without using the transfer head 66 . The kinds and sizes of the bumps Bp, the sizes of the openings of the mask and mesh, the dimension of the fine lugs, and the details of the particle arranging device shown and described are only illustrative. In addition, this embodiment is applicable not only to the bumps Bp but also to other various kinds of particles.
In summary, in the illustrative embodiment, bumps can be easily and surely arranged and transferred without resorting to strict control over the diameter of the bumps, the flatness of the leads of a TAB tape, the flatness of a bonding tool, and the parallelism of a stage and a TAB tape or an LSI chip. This successfully increases the yield of bonding using the TAB system or the flip-chip bonding system, and thereby enhances the productivity of semiconductor devices.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.
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A device for arranging conductive particles in a preselected pattern for the connection of electric circuit boards or electric parts is disclosed. Particularly, a device capable of surely and efficiently transferring, e.g., solder bumps to the electrode pads of a semiconductor chip or the leads of a TAB (Tape Automated Bonding) tape and a conductive particle transferring method using the same are disclosed.
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RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/EP2008/058832, filed Jul. 8, 2008, which claims priority to United Kingdom Application No. 0713304.4, filed Jul. 9, 2007, which are incorporated herein by reference in their entirety. Additionally, the contents of any patents, patent applications, and references cited throughout this specification are hereby incorporated by reference in their entireties.
TECHNICAL FIELD
The present invention relates to a process for the synthesis of conducting polymer films formed by polymerization of a heteroaromatic molecule. The invention relates particularly to the synthesis of polymerized thiophene films, for example poly(3,4-ethylenedioxythiophene) (PEDOT) films.
BACKGROUND
Development of materials for use as electrodes in optoelectronic devices, such as field effect transistors (FETs), light emitting diodes, photovoltaic devices (PVDs) and solar cells is an area of huge research interest. Traditionally, widely used electrode materials have been indium-tin-oxide (ITO) as a transparent front electrode with a metal, such as aluminium, barium, calcium, gold and the like, as a back electrode. However, ITO suffers from cracking and loss in conductivity when deposited on flexible substrates and subjected to bending. Furthermore, the fast development of the optoelectronic display industry has dramatically pushed up the price of indium, the raw material for the production of ITO electrodes. Alternatives to inorganic electrode materials such as ITO are urgently needed.
The provision of flexible electrode materials to address problems of cracking and consequent loss in conductivity seen with ITO electrodes is of great importance. Conducting polymer thin films are seen as an attractive alternative. Rapidly growing interest in polymer electronics has arisen from the promise of attaining lightweight, flexible electronic components that can be manufactured at low cost.
In recent years, poly(3,4-ethylenedioxythiophene) (PEDOT) has emerged as an excellent candidate material for flexible polymer electronics. PEDOT is a conducting polymer which has good stability and optical transparency in its conducting state. PEDOT itself is insoluble, but synthesis in the presence of the water soluble electrolyte poly(styrene sulfonic acid) (PSS), allows a stable PEDOT-PSS suspension to be formed that shows good film forming properties. When subjected to special treatment, such as secondary doping with glycerol or ethylene glycol, PEDOT-PSS films can have a conductivity which reaches 160 S/cm. This conductivity is, however, still far from the conductivity (in the region of 4000 S/cm) seen for ITO. PEDOT-PSS films are described in Jonsson, S. K. M., et al., Synthetic Metals, 2003. 139(1): 1-10, J, Huang., et al., Advanced Functional Materials, 2005. 15(2): 290-296 and J, Ouyang., et al., Polymer, 2004. 45(25): 8443-8450.
In order to seek further improvement in conductivity, chemical synthesis of PEDOT conducting polymer films has been widely investigated. Vapour phase polymerized PEDOT (VPP-PEDOT) films are particularly attractive, providing higher conductivity and transmission than PEDOT-PSS films. VPP-PEDOT synthesis is described in Jinyeol, K., et al. Synthetic Metals, 2003. 139(2): 485-489, Winther-Jensen, B., et al., Macromolecules 2004. 37(16): 5930-5935 and Winther-Jensen, B. and West, K.2004. Macromolecules 37(12): 4538-4543 and in WO2005/103109.
The polymerization process which leads to the formation of PEDOT involves (1) the oxidation of a 3,4-ethylenedioxythiophene (EDOT) monomer when an electron is withdrawn from an EDOT heteroaromatic ring, (2) the combination of two oxidized monomers to form a dimer with release of a proton, and (3) further oxidation of dimers and formation of trimers, etc, until long PEDOT chains are formed. The ionization potential of EDOT monomers and PEDOT dimers, trimers and infinite long chains are 1.1, 0.46. 0.16 and −0.25V (vs Ag/Ag+), respectively. Consequently, as soon as oligomers are formed, polymerization accelerates rapidly.
Existing VPP-PEDOT synthetic routes comprise three key steps: oxidant deposition, monomer polymerization and residual oxidant removal. Firstly, an oxidant layer is deposited on a substrate, generally glass or plastic, by spin coating or by gravure or screen printing methods carried out with a solution of an oxidant and an amine or amide polymerization inhibitor in an organic solvent. Following drying by heating, the substrate bearing an oxidant layer is transferred into a reaction chamber. The substrate bearing an oxidant layer is exposed to vapourized EDOT monomer in the reaction chamber. Polymerization takes place as the EDOT monomer vapour contacts the oxidant layer on the substrate, thereby forming a PEDOT film on the substrate surface. After the polymer film has formed, the substrate bearing a PEDOT film is washed to remove residual oxidant and any remaining polymerization inhibitor. Generally this washing is carried out with ethanol or methanol.
There are, however, several disadvantages to the existing VPP-PEDOT synthesis route described above. First, the PEDOT film synthesized on contact of the vapourized EDOT monomer with the oxidant layer has weak adhesion to the surface of the substrate. Thus, the PEDOT film easily loses contact with the substrate during the washing step. As a result of this, wrinkles may occur in the VPP-PEDOT film or the whole VPP-PEDOT film may peel off from the substrate into the wash solution. Second, due to the weak adhesion described above, it is not possible to thoroughly wash the VPP-PEDOT film and it is difficult to ensure complete removal of oxidant. This can cause problems with film morphology and may cause other problems when the film is used as an electrode. For example, the residual oxidant can crystallize as the temperature increases and cause deformation of the VPP-PEDOT film. The oxidant is also chemically reactive and therefore may cause degradation of the conjugated polymers, oligomers, dendrimer or other molecules to be used as the active layer in plastic electronic devices. Third, existing VPP-PEDOT synthetic routes generally require a large amount of organic solvent in the washing (oxidant removal) step. This is neither cost effective, nor environmentally friendly.
In order to obtain a VPP-PEDOT film with a smooth surface by using existing synthetic routes, it is necessary to immerse the substrate bearing a PEDOT film in organic solvent for a long time and use a large amount of solvent to wash the surface. The substrate must be handled with great care. Any quick movement of the substrate in the washing solvent may induce the tearing of the VPP-PEDOT film, or peeling off of the entire film into the solvent. In general, film morphology is sacrificed to ensure that the PEDOT film is maintained intact on the substrate.
SUMMARY OF THE INVENTION
The present invention provides a new VPP synthetic route for polymerised thiophene films which addresses the problems of existing synthetic routes. The films prepared by the new synthetic route are very smooth, and the whole synthetic route is easily controlled and suitable for production of large area films. The synthetic route can also be used for the synthesis of polymers from related heteroaromatic monomers, for example where the thiophene S atom is replaced by Se (selenophene), nitrogen (pyrrole), O (furan), or
The first aspect of the invention therefore relates to a process for the production of a polymer film by vapour phase polymerization (VPP), the process comprising the steps of:
(1) providing a solution comprising an oxidant, an amine or amide polymerisation inhibitor and an additive, wherein the additive is a water soluble polymer; (2) applying the solution to a surface of a substrate so as to form an oxidant, polymerisation inhibitor and additive mixture layer on the surface of the substrate; (3) exposing the oxidant, polymerization inhibitor and additive containing layer to a vapourized heteroaromatic monomer and allowing polymerization to proceed to form a polymer film on the surface of the substrate.
In a preferred embodiment, the solution comprising an oxidant, an amine or amide polymerisation inhibitor and an additive is an aqueous solution.
In a preferred embodiment, following step (2), the process further comprises the step (2a) of removing solvents from the oxidant, polymerisation inhibitor and additive mixture layer. Preferably, solvents are removed by heating. Preferably, the substrate is heated at 80-120° C. for 1-5 min (e.g. on a hot plate) in a dry atmosphere or under vacuum.
Removal of solvents prior to polymerisation step (3) improves film morphology and reduces the risk of the polymerised film being lifted from the substrate.
In a preferred embodiment, polymerization step (3) is carried out at a temperature in the range from 40° C. to 3° C. Preferably, polymerization is carried out in a dry chamber. Preferably, the reaction chamber is dried by heating and/or purging with nitrogen, argon or dry air.
The oxidant, polymerisation inhibitor and additive-containing layer are heated in a dry atmosphere or in vacuum in step (2a), and the polymerization chamber is dried in step (3) to avoid the effect of water on polymerization. Removing water from the polymerization reaction leads to the production of a polymer film with improved surface morphology.
In a preferred embodiment, the process further comprises step (4) of washing the substrate bearing a polymer film as produced in step (3) with water or an aqueous or water miscible solvent. The purpose of this step is to remove remaining oxidant and polymerization inhibitor. Preferably, step (4) comprises heating the substrate (for example by transferring the substrate onto a hot plate for a short period of time, preferably between 1 and 10 minutes) in an inert atmosphere, then immersing the substrate in water or an aqueous solvent for a certain time and finally taking the substrate bearing a polymer film out of the solvent, and allowing it to dry. Preferably, drying is allowed to occur naturally in air or under another suitable atmosphere (e.g. an inert atmosphere).
In a further preferred embodiment, the process further comprises step (5) of depositing a layer of polymeric acid onto the polymerized film. Preferably, this is achieved by spin coating with a solution of polymeric acid. This polymer acid layer helps to stabilise the conductivity of the film during subsequent annealing. Preferably, the polymeric acid is a water soluble polymeric acid dissolved in water to produce the polymeric acid solution. More preferably, the polymeric acid is poly (4-styrene sulfonic acid) (PSSA), poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAAMPSA) or poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT-PSS). Most preferably, the polymeric acid is PSSA.
In a preferred embodiment, the additive is a water soluble polymer selected from polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyacrylamide, carboxymethylcellulose, hydroxyethylcellulose and a mixture of polymers comprising at least one, preferably two, of the listed polymers. Preferably, the additive is polyethylene oxide (PEO) or polyvinyl alcohol (PVA).
In a preferred embodiment, the polymer film comprises a polymer of a monomer of any of formulae I to V
wherein X and Y may be, independently, —O— or CH 2 —, with the proviso that at least one of X and Y is —O—; R is optionally substituted C 1-4 alkyl; and Z is hydrogen or NH 2 . Preferably, X and Y are both —O—. Preferably, Z is hydrogen.
Preferably, R is an optionally substituted C 1-4 alkylene biradical, selected from, for example, —CH 2 —, —CH 2 CH 2 —, —CH 2 CH 2 CH 2 — and —CH 2 CH 2 CH 2 CH 2 —, wherein in R, if substituted, one or more hydrogen, preferably one, two or three hydrogen atoms are replaced with a substituent selected independently from hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, C 1-6 -alkoxycarbonyl, C 1-6 -alkylcarbonyl, formyl, aryl, amino, C 1-6 alkylamino, di(C 1-6 alkyl)amino, carbamoyl, mono- and di(C 1-6 alkyl)amino-C 1-6 -alkyl-amino-carbanoyl, C 1-6 alkylcarbonylamino, —CN, carbamido, C 1-6 alkanoyloxy, —SO 3 H, —SO 2 H, C 1-6 -alkylsulphonyloxy, C 1-6 -alkylsulphonyl, nitro and halogen. Preferred substituents are hydroxy, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 -alkoxycarbonyl, C 1-6 -alkylcarbonyl amino, C 1-6 alkylamino, di(C 1-6 alkyl)amino and halogen. More preferably, R is an unsubstituted ethylene or propylene biradical (—CH 2 CH 2 — or —CH 2 CH 2 CH 2 —)
Most preferably, R is unsubstituted ethylene (—CH 2 CH 2 —) and both X and Y are —O—, such that the monomer is ethylenedioxythiophene (EDOT) and the thiophene polymer is poly(3,4-ethylenedioxythiophene) (PEDOT).
In a preferred embodiment, the oxidant is an Iron (III) salt, preferably an Fe (III) sulphonate, Fe (III) chloride or an Fe(III) phosphate, more preferably the oxidant is iron p-toluenesulfonate heptanedionate.
In a preferred embodiment the ratio (calculated by weight) between the oxidant and the additive in the oxidant solution is in the range between 1:0.006 and 1:0.92. More preferably, the additive is PVA and the ratio between oxidant and PVA is in the range between 1:0.042 and 1:0.92 or the additive is PEO and the ratio between oxidant and PEO is in the range between 1:0.23 and 1:0.92.
In a preferred embodiment, the additive is PVA and the molecular weight of PVA is at least 1000-14000, and more preferably at least 7000-10000. In another preferred embodiment, the additive is PEO and the molecular weight of PEO is at least 1000, and more preferably at least 6400.
In a preferred embodiment the amine or amide polymerization inhibitor is a tertiary amine, a tertiary amide or an aromatic amine. Preferably, the inhibitor is a cyclic tertiary amine (such as 4-methylmorpholine, 1-methyl piperidine and 1-methylpyrrolidone), a cyclic tertiary amide (such as N-methyl-pyrrolidone, N-vinyl-pyrrolidone and 3-methyl-2-oxozolidinone) or an aromatic amine (such as pyridine, N-methyl-imidazole, quinoline and isoquinoline). The oxidant solution may comprise a mixture of amines and/or amides. Most preferably the inhibitor is pyridine.
In a preferred embodiment, the substrate comprises a polymeric plastic material, a metal foil or glass. The polymeric plastic material is preferably selected from polyolefins such as polyethylene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polypropylene, polystyrene, thermoplastics, fluoro-polymers such as polytetrafluoroethylene, tertafluoroethylene-hexafluoropropylene copolymers and poly-vinyl-difluoride, polyamides such as Nylon® and polyvinylchloride.
In a preferred embodiment, a plastic film substrate comprising multilayer barriers (such as SiOx and SiNx, wherein 2>x>1 and 1.3>y>0.6) may be used. The barriers are used to limit oxygen and water penetration through the plastic film and also to planarize its surface.
In a preferred embodiment of the invention, in step (3) the substrate bearing an oxidant, polymerisation inhibitor and additive-containing layer is exposed to vaporised heteroaromaticmonomer (preferably EDOT monomer) in an in vacuo reaction chamber. Preferably, the vacuum in the reaction chamber is from 210 to 0.1 ton, more preferably, the vacuum is 75 torr. Preferably, liquid heteroaromatic monomer is introduced into the vacuum by pre-application on a substrate (eg glass) in the chamber or by injection into the reaction chamber. The vacuum causes the liquid monomer to vaporise.
In an alternative embodiment of the invention, in step (3) the substrate bearing an oxidant, polymerisation inhibitor and additive-containing layer is exposed to vapourized heteroaromatic monomer (preferably EDOT monomer) brought into the reaction chamber by flowing N 2 , Ar or dry air over liquid heteroaromatic monomer held in a container within a sealed path between the gas source and the chamber.
In a preferred embodiment, polymerisation step (4) is carried out at a temperature below 40° C. Preferably, the temperature is 30° C. or below, 22° C. or below or 8° C. or below. More preferably, the temperature is 3-30° C., 3-26° C., 3-22° C. or 3-8° C. It has been found that carrying out low temperature VPP of a polymerised heteroaromatic film as set out above leads to the production of a thiophene film with increased conductivity.
In a preferred embodiment, the solution comprising an oxidant, a polymerisation inhibitor and an additive is an aqueous solution comprising a mixture of solvents, namely water and a water miscible solvent, for example an alcohol, such as methanol, ethanol or butanol.
In an alternative embodiment, the oxidant, amine or amide polymerisation inhibitor and an additive are dissolved in a mixture of toluene and an alcohol solvent such as methanol, ethanol or butanol. It should be noted that the water soluble polymer additive may be solubilised in an alcohol solvent.
In a preferred embodiment, the solution comprising an oxidant, a polymerisation inhibitor and an additive is prepared by preparing a first solution comprising the oxidant and polymerisation inhibitor and a second solution comprising the additive and then mixing the first and second solutions. The first and second solutions may comprise the same or different solvents.
In another preferred embodiment glycol or glycerol is added to the oxidant solution to increase the adhesion on the polymerised film to the substrate.
The process described above is robust and enables the production of smooth and highly conductive VPP-PEDOT films at a high yield. The VPP-PEDOT film produced by the process has good substrate adhesion. This allows for thorough washing in water, without wrinkling or film detachment, improving film morphology and yield.
In a second aspect, the invention provides a polymer film produced by a process according to the first aspect of the invention. Preferred features of the first aspect apply to the second aspect of the invention.
The invention may be put into practice in various ways and a number of specific embodiments will be described by way of example to illustrate the invention with reference to the accompanying figures, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a three dimensional AFM image of a VPP-PEDOT film without the polymer additive, wherein a fold has formed. FIG. 1B shows an AFM image of VPP-PEDOT growth on the layer deposited from solution with iron p-toluenesulfonate heptanedionate:PVA 1:0.085, as shown in solution table 1.
FIG. 2 shows transmission spectra of VPP-PEDOT film (solid line) and VPP-PEDOT with PVA additive (dashed line) prepared with iron p-toluenesulfonate heptanedionate:PVA 1:0.085, as in solution table 1. The thickness and sheet resistance are also shown in the figure.
FIG. 3 shows a plot of the conductivity of VPP-PEDOT films vs. synthesis temperature. Synthesis was carried out using a mixed solution containing 17% iron p-toluenesulfonate heptanedionate and 0.6% pyridine in a toluene and butanol (1:1) solution.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be illustrated by reference to the following non-limiting examples.
EXAMPLES
The raw materials for VPP-PEDOT synthesis are EDOT monomer (Baytron M from H. C. Stark), Iron p-toluenesulfonate heptanedionate, pyridine, glycerol, polyethylene oxide (PEO, Mw 6400), polyvinyl alcohol (PVA, Mw 7000-10000), methanol and ethanol from Sigma-Aldrich. These raw materials were obtained commercially and used with no further purification. Glass substrates were cleaned by using 20% Decon 90 and deionised (DI) water in an ultrasonic bath for 30 minutes, respectively.
As an alternative to glass, metal foils or plastic substrates can be used, cleaned prior to use, for example with ethanol solution for 10 minutes in an ultrasonic bath.
Example 1
Comparison of VPP-PEDOT Produced with and without Polymer Additives
VPP_PEDOT Production a Method for Mass Production Using PVA/PEO Additives Solution Preparation
Aqueous solutions comprising an oxidant, a polymerization inhibitor and a polymeric additive were prepared by first preparing an oxidant solution and an additive solution and then combining these solutions. Oxidant solution (1), for use with PVA, was produced by dissolving 6 g Iron p-toluenesulfonate heptanedionate, 0.2 g pyridine, 0.8 g glycerol in 30 g iso-propanol. Oxidant solution (2), for use with PEO, was made by replacing the iso-propanol with DI water and keeping the other materials in the same amount as in solution (1). Glycerol is a viscous, water-miscible solvent which is included to tailor the viscosity of the oxidant solution. A PVA solution was made by dissolving 0.5 g PVA in 3 g DI water and a PEO solution by dissolving 0.6 g PEO in 3 g DI water. The solutions were stirred for several hours on a hot plate at 80° C. and filtered through 0.2 micrometer filters. Oxidant solutions containing different concentrations of PVA and PEO additive were prepared by mixing the substances described above in the ratios listed in the following tables.
TABLE 1
solutions with PVA additive
Iron p-toluenesulfonate heptanedionate/PVA
1:0.00
1:0.006
1:0.012
1:0.042
1:0.085
1:0.12
1:0.37
Oxidant solution (1)
0.5 g
0.5 g
0.5 g
0.5 g
0.5 g
0.5 g
0.5 g
PVA solution
0.0 g
0.006 g
0.013 g
0.03
0.06
0.09
0.26 g
Extra DI water
0.0 g
0.06 g
0.06 g
0.0 g
0.0 g
0.0 g
0.0 g
TABLE 2
solutions with PEO additives
Iron p-toluenesulfonate
heptanedionate/PEO
1:0.23
1:0.46
1:0.69
1:0.92
Oxidant solution (2)
3 g
3 g
3 g
3 g
PEO solution
0.1 g
0.2 g
0.3 g
0.4 g
VPP-PEDOT with polymer additive films were prepared through depositing oxidant, pyridine and PVA (or PEO) mixture on glass substrates by spin coating from the above solutions. This was followed by a drying step at 80-120° C. on a hot plate for 5 min in nitrogen atmosphere. Then the substrates were transferred into a vacuum reaction chamber, containing a piece of cleaned glass on which a few drops of EDOT liquid monomer had been placed. Any water absorbed inside the chamber, on the surface of the chamber walls was pre-removed by heat and N 2 purge. The vacuum was typically 75 torr and the temperature 20° C.
As the EDOT monomer contacted the oxidant layer, polymerization occurred and a PEDOT film formed on the substrate surface. This was monitored by appearance of the characteristic light blue colour of the PEDOT film. Then the substrates bearing a PEDOT film were transferred from the vacuum chamber onto a hot plate at 50° C. for 30 minutes in a nitrogen atmosphere. This heating acts to aid polymerisation of any monomer remaining in the film layer, and the nitrogen atmosphere is to avoid water absorption in the polymerized film and avoid hole formation. After the heating step, the substrate bearing a PEDOT film was immersed in DI water. The substrates bearing VPP-PEDOT films with PVA or PEO additives were agitated vigorously in order to aid oxidant removal, whilst leaving the VPP-PEDOT film intact on the substrate.
Preparation of VPP-PEDOT Film Using a Known Synthetic Route
For purposes of comparison, VPP-PEDOT films were prepared using a known synthetic route.
(1) Deposition of Oxidant Layer on a Glass Substrate
An oxidant solution was produced by dissolving 0.6 g Iron p-toluenesulfonate heptanedionate and 0.02 g pyridine in 3 g butanol (or butanol and toluene mixture solution with ratio 1:1), and stirring for one hour on a 80° C. hot plate. The oxidant (iron p-toluenesulfonate) layer was deposited on a glass substrate by spin coating. Drying was carried out by heating to 80-100° C.
(2) Polymerization
The substrate bearing an oxidant layer was transferred into a reaction chamber under vacuum. The substrate bearing an oxidant layer was exposed to vapourized EDOT monomer in the reaction chamber. Polymerization takes place as the EDOT monomer vapour contacts the oxidant layer on the substrate, thereby forming a PEDOT film on the substrate surface.
(3) Oxidant By-Product Removal
The substrate bearing a PEDOT film was transferred from the vacuum chamber onto a hot plate at 50° C. for 30 minutes, and then immersed in ethanol/methanol (1:1) solution for 3 hours. Then the substrate with PEDOT film on top was slowly moved out of the solution, and allowed to dry naturally in air. The substrate with a VPP-PEDOT film was gently washed to avoid the whole film peeling off.
During the known synthetic process, the oxidant-containing layer formed after the deposition step has weak adhesion to the substrate as compared to a polymeric film. This adhesion becomes even weaker after EDOT deposition and partial polymerization in the oxidant-containing layer. As a substrate bearing such a PEDOT/oxidant layer is immersed into solvent, especially water, the whole layer can easily peel off, or lift up and drop back to the substrate, forming folds or wrinkles. A wrinkle formed during the washing process is shown in the AFM image of FIG. 1A . The yield of wrinkle free VPP-PEDOT films is very low. It is generally necessary to sacrifice surface morphology in order to ensure that films are maintained intact. The process of the invention removes the necessity for this sacrifice, enabling the production of smooth VPP-PEDOT film that adheres well to the substrate.
In the process of the invention, additive polymers such as PVA and PEO are blended with the typical oxidant layer material before deposition. After PEDOT polymerization, the two polymers PEDOT and PVA or PEO form a matrix containing water soluble and water insoluble polymers on the substrate, which greatly increases adhesion between the oxidant blend layer and the substrate, and the peeling off and wrinkle phenomena are greatly reduced.
The ratio of iron p-toluenesulfonate heptanedionate to PVA/PEO in the solution is important for increasing the adhesion of the prepared films to the substrates. The best ratio of iron p-toluenesulfonate heptanedionate to PVA is between 1:0.042 and 1:0.12. With a further increase or decrease in PVA content the prepared films start to lose adhesion to the substrate or tear off during the water washing step. The PEO additive in the oxidant solution is also very helpful to increase the adhesion of prepared films to the substrates. For an iron p-toluenesulfonate heptanedionate to PEO ratio from 1:0.23 to 1:0.69, all of the prepared films showed good adhesion to the substrate even under harsh washing conditions.
As an example, the AFM image of a VPP-PEDOT film with PVA additive shows no wrinkles (c. f. FIG. 1B ). This film was prepared from a solution with an iron p-toluenesulfonate heptanedionate:PVA ratio of 1:0.085, as in solution table 1. The presence of these additives causes strong adhesion of the film to the substrate. This allows the use of a harsher washing method, with water to clean the surface, removing most of the unused oxidant and by-products from the VPP-PEDOT film.
Sheet resistance and transmission are two important parameters for the application of VPP-PEDOT films as transparent electrodes. The additives are totally transparent in the visible range and they therefore do not reduce the transparency of the VPP-PEDOT film.
FIG. 2 shows transmission spectra of a VPP-PEDOT film and a VPP-PEDOT film prepared using the PVA additive from a solution with iron p-toluenesulfonate heptanedionate:PVA 1:0.085, as in solution table 1. The thickness and sheet resistance are also shown in FIG. 2 . The transmission of VPP-PEDOT with PVA is 5% higher than that of VPP-PEDOT film, and has similar sheet resistance around 250 ohm per square. This clearly demonstrates the advantages of the invention, an increase in the yield of wrinkle free VPP-PEDOT films with no loss in transmission or degradation in electrical properties. The precise concentration of additive used can be selected, depending on the specific properties desired for the intended application of the PEDOT film.
Example 2
VPP-PEDOT Film with Pin Hole Free Substrate Coverage and High Conductivity
A series of VPP-PEDOT thin films was prepared using the known synthetic route described in example 1, depositing the oxidant layers from an oxidant solution containing 17% iron p-toluenesulfonate heptanedionate and 0.6% pyridine in a toluene and butanol (1:1) solution. There were no polymer additives in the solution. The temperatures for polymerization were varied from 3 to 40° C.
The conductivity of the VPP-PEDOT film is considerably increased by reducing the synthesis temperature. The conductivity of VPP-PEDOT film vs synthesis temperature is shown in FIG. 3 . The highest conductivity, 1200 S/cm, was obtained at 3° C. It is considered that the high conductivity of VPP-PEDOT films synthesized at low temperature is predominantly due to the low growth rate, which is favorable for the formation of polymer chains with long conjugation lengths. A corresponding trend in increasing conductivity with reduction in polymerization temperature has been observed for VPP-PEDOT formation carried out according to the additive process of the present invention.
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The invention relates to a process for the synthesis of conducting polymer films by vapor phase polymerization. The invention relates particularly to the synthesis of polymerized thiophene films, for example poly(3,4-ethylenedioxythiophene) (PEDOT) films.
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FIELD OF THE INVENTION
This invention is related to storage devices and in particular to a bathroom accessory for the storage and scenting of toilet paper tissue rolls.
BACKGROUND OF THE INVENTION
Tissue paper holders are common fixtures found in the home, business or commercial bathrooms. The tissue roll allows a consumer to simply remove tissue as necessary by unwinding the tissue roll as it is held on a spindle. Nearly all bathrooms have at least one tissue paper dispensing mechanism designed to hold a single roll of tissue paper. The problem that arises, to which this invention addresses, is when a replacement tissue roll is necessary. While a housekeeper or owner of the home may know where additional tissue rolls are stored, the situation does arise when a guest to the home is using the facilities when a tissue roll has expired. The guest may need to search closets and cabinets to find a replacement roll. Should the facilities be used frequently, it is quite possible that the last person may not notice the lack of tissue paper leading to a precarious if not embarrassing situation.
One method of addressing the problem is to dispose of a partially expired tissue roll before all the paper is used to prevent an inadequate supply. Alternatively, additional tissue rolls may be placed near the water closet or on a counter top. Placement of extra tissue rolls around the bathroom is unsightly and may lead to spoiling of the tissue paper due to its natural absorbing ability to pick up moisture and odors as later described.
To address these problems various teachings have been made in the prior art such as U.S. Pat. No. 3,316,040 which discloses a storage unit for tissue rolls having a cylindrical shaped body with a frontal door that can be raised to access rolls placed therein. A cover to the storage unit allows for insertion of tissue rolls to maintain supply.
U.S. Pat. No. 2,440,974 issued to Resch discloses a toilet paper humidifier housing that allows for the dispensing of tissue paper. The Resch device requires the use of a liquid to cause saturation of lining walls and does not teach the use of a storage device or scenting device wherein the dry scent material is placed above the stored tissue rolls.
U.S. Pat. No. 3,413,049 discloses a tissue roll holder having a locking mechanism for positioning rolls. The locking mechanism is inserted through the spindle wrapping aperture of the tissue roll.
U.S. Pat. No. 4,177,958 discloses a tissue roll holder and dispensing mechanism having a cylindrical tower to accommodate multiple tissue rolls. A support shelf allows the tower to further operate as a tissue dispenser.
Various design patents also disclose toilet paper tissue roll storage containers. Design U.S. Pat. Nos. 201,099; 307,086; 314,301; and 330,984 all set forth ornamental shapes for tissue roll holders and/or dispensers.
While the prior art addresses the need for storage of multiple tissue rolls, none of the prior art discloses the problems created with storing tissue paper after it is removed from its shipping package. The aforementioned storage devices require the tissue rolls to be removed from its packaged condition and placed into a storage device for subsequent use. While the availability of the tissue roll for subsequent use is a well documented benefit, a disadvantage is the absorbing qualities of the tissue paper having the ability to absorb unwanted foul bathroom odors. Should bathroom odors be absorbed, the odor can be released over a period of time as the tissue roll is dispensed.
Manufacturers of tissue roll paper acknowledge this situation by producing pre-scented tissue rolls. The fragrance is stronger than what would be commonly absorbed in a bathroom thus providing a nice scent to paper. However, once the tissue roll is unpacked the fragrance will begin to dissipate in the surrounding environment. Should the scented tissue rolls be stored in an unsealed container such as the aforementioned devices, the scent may completely dissipate before use. In addition, many of the pre-scented fragrances are objectionable to those consumers with a sensitive sense of smell.
Thus what is needed in the art is an apparatus having the ability to store multiple tissue paper rolls in an attractive container providing ease of accessibility and fresh scenting.
SUMMARY OF THE INVENTION
The present invention satisfies this need by the provision of a free standing storage container and scenting apparatus having the ability to house from two to four tissue rolls in a vertical stacked arrangement. The storage apparatus provides an enclosed interior chamber preventing the tissue rolls from absorbing unwanted odors. Along an upper portion of the storage apparatus is located a support shelf for placement of scenting materials. The support shelf is sized to allow air flow into an interior chamber housing providing the tissue rolls with a fragrance as chosen by the consumer.
The upper surface of the holder includes ventilation holes allowing the fragrance to expand into the bathroom area. Potpourri may be used as a scenting material with accessibility to renew the material with the addition of potpourri oil. Similarly, scent blocks can be placed on the support shelf eliminating the need for air fresheners that take up valuable counter space. Unique to this invention is the ability to make the tissue paper housings colorful by use of flowers and the like indicia along the sidewalls. Further, the housings can be concealed within various fictitious characters such as a snowman and/or replicas of objects such as automobiles.
Unlike spray air fresheners the instant apparatus maintains the fragrance by continually applying a fragrance scent to the stored tissue paper. Thus, when the tissue roll is utilized, the fragrance that was absorbed will provide a lingering scent in a similar fashion as store purchased scented tissue rolls.
Therefore, an objective of the instant invention is to provide improvements in storage containers for toilet paper tissue rolls, while maintaining the need to provide a storage housing which is easily accessed.
Still another objective of this invention is to provide a low cost enclosed tissue roll storage container for preventing the spoilage of unpackaged tissue rolls and further providing a means for scenting of tissue rolls according to the preference of the consumer.
Yet still another objective of the instant invention is to provide a concealed area for maintaining of various scenting materials including disposable air freshening solids or renewable air freshening materials such as potpourri.
Still another objective of the instant invention is to conceal tissue paper within fictitious characters such as a snowman or replicas of automobiles and the like.
Other objectives and advantages of the instant invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objectives and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the instant invention depicting a cylindrical shaped tissue roll housing that has a removable scenting material canister and is sized to accommodate three tissue rolls;
FIG. 2 is a perspective view of a second embodiment of the instant invention depicting a cylindrical shaped tissue roll housing having a rotatable access door and sized to accommodate three tissue rolls;
FIG. 3 is a perspective view of a third embodiment of the instant invention depicting cylindrical shaped tissue roll housing having double doors for accessing of a chamber sized to accommodate two tissue rolls;
FIG. 4 is a perspective view of the instant invention concealed within a snowman; and
FIG. 5 is a perspective view of the instant invention concealed within a replica of an automobile.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to FIG. 1, a first embodiment of the instant invention is shown. The toilet paper tissue roll scenting and storage apparatus 10 includes a tissue paper housing 12 and a scenting material canister 14. The housing 12 is essentially a cylindrical shell 16, one end of which is bounded by a circular bottom wall 18. The housing 12 has an open end 20 which is sized to receive the scenting material canister 14. The housing creates an interior chamber 21 that is sized to accept 3 stacked rolls of tissue paper 32, 32 1 , 32 11 . simultaneously. The shell 16 includes inspection apertures 23 to allow monitoring of the contents of the housing 12.
The scenting material canister 14 is defined by a circular top plate 22 and a circular bottom plate 24 which are spaced apart by a continuous sidewall 26 that extends orthogonally between them. The sidewall 26 and bottom plate are permanently jointed, while the top plate 22 may be removed. An attachment ring 28 extends downward from the top plate 22. The attachment ring 28 includes threads (not shown) sized to engage threads (not shown) included along the top of the canister sidewall 26. The top plate 22 may be unscrewed from the sidewall 26 to reveal an interior compartment 30 within the canister 14. With the top plate 22 removed, scenting materials (not shown) are placed into the exposed interior compartment 30, supported by the bottom plate 24. The bottom plate 24 is perforated by through holes 34 which allow osmotic transfer of scent from the scenting materials located in the canister 14 to the tissue paper 32, 32 1 , 32 11 stored in the housing 12, below. Top plate 22 has through holes 35 which similarly allow scent transfer into the room containing the apparatus 10.
The top plate 22, bottom plate 24, and sidewall 26 are sized so that the canister 14 may be easily inserted into the open end 20 of the tissue paper housing 12. Specifically, the outer diameter of the top plate 22 is substantially the same as the outer diameter of the cylindrical shell 16, and the outer diameter of the bottom plate 24 is substantially equal to the inner diameter of the cylindrical shell 16. With these dimensions, the canister will remain suspended at the top of the housing 12, even if the housing is partially empty. A handle 36 extends from the upper surface 38 of the top plate 22, to ease manipulation of the canister 14.
Now referring to FIG. 2, shown is a second embodiment of the instant invention setting forth a tissue paper scenting and holder apparatus 50 defined by a bottom wall 52 having a circular shaped perimeter edge 54 with a door track 56 formed along at least a portion of the perimeter edge 54. The bottom wall 52 is spaced apart from a top wall 58 a fixed distance by sidewall 60 in order to accommodate multiple tissue rolls 102, 104 and 106. The top wall 58 is formed into a circular shape having an upper perimeter edge and door track so as to form a mirror image of said bottom wall. Side wall 60 is permanently secured to the bottom wall 52 and top wall 58 forming a partial cylindrical tower. A one piece door 62 having a vertical side wall operatively associated with the upper and lower door track forming an interior chamber for the tissue rolls by sliding said door 62 along the door track. Handle 64 is available to assist in sliding of said door 62. The bottom wall 52 may be weighted so as to prevent accidental tippage should a person inadvertently try to open the door 62 without supporting the base securely. Inspection apertures 63 provide interior viewing.
Support shelf 66 having a surface area equal to or less than bottom wall 52 is positioned along upper portion of inner surface 68 of the side wall 60. The support shelf 66 includes opening 70 allowing access to the shelf for placement of scenting materials. As noted, a plurality of through holes 72 are provided for scenting of the tissue paper placed within the housing while the door 62 is in a closed position. The door 62 further seals the opening 72 for scenting the interior chamber. A plurality of through holes 74 is further provided along the top wall 58 allowing a controlled release of the fragrance into the bathroom area. The storage device is sized to house from two to four tissue rolls in a vertical stacked arrangement.
Now referring to FIG. 3 shown is a third embodiment of a tissue paper scenting and storage apparatus 76 having a base housing defined by a bottom wall 78 with a circular shaped perimeter edge 80 spaced apart from a top wall 82 having a circular shaped perimeter edge 84 coupled together by side wall 86 sized to accommodate multiple tissue rolls. Side wall 86 forms a partial cylinder tower with a first rotatable cover 88 hingedly attached to the sidewall 86 by hinge member 90. Similarly, second cover 92 is hingedly attached to side wall 86 by hinge member 94. Inspection apertures 85 provide interior viewing.
Support shelf 96 is available for placement of scenting material such as potpourri having a plurality of through holes 97 available for scenting of tissue paper placed within the interior chamber when double doors 88 and 92 are placed into a closed position. Top wall 82 includes a plurality of through holes 98 allowing the fragrance dispersion into the bathroom area when the cover 84 is placed upon the support shelf 96. Unlike potpourri, open containers or conventional scenting sticks, the limited access openings 98 inhibit a total release of the fragrance thus forcing the scenting of the interior chamber and stored tissue rolls through openings 97. Cover 84 may be simply placed upon the support shelf or coupled by hinge member 99 allowing the cover 84 to be rotated upward for access to the support shelf 96 and placement of associated scenting material. It should be noted in this embodiment the bottom wall 78 may be weighted. Hinge members 90 and 94 may also be conventional hinge members, longitudinal piano hinge type members, or plastic fold lines depending upon the materials of construction. A forth embodiment, not shown, assimilates the third embodiment by use of a single door member in place of the double door wherein the side wall is simply enlarged allowing the use of a single door for access into the interior chamber.
Now referring to FIG. 4 shown is an embodiment of the instant invention placed within a fictitious snowman character 120. The snowman housing includes a head 122 securable to body portion 124 encompassing an interior chamber 126 for placement of tissue rolls 128 therein. The chamber may assimilate the storage housing shown in FIGS. 2 or 3. Alternatively, a hat portion 132 is removable from the head 122 at break line 130 to conceal an opening accessing interior chamber 126. As set forth in previous embodiments, the scenting material is positional above the interior chamber with ventilation holes 134 for scenting the immediate area. The hat 138 includes a support shelf, not shown, for placement of the scenting material. Buttons 136, conceal inspection ports used to determine the amount of tissue rolls placed within the chamber 126.
FIG. 5 is yet another example of housing tissue rolls within a unique housing. Depicted is a replica of an automobile 150, based upon the first embodiment having a body 152 supporting multiple tissue rolls 156 in an interior chamber. The trunk 154 of the device may be pivoted at hinge point 155 allowing access to the chamber for removal of stored tissue rolls. In this embodiment a scenting shelf is placed within the engine compartment located beneath hood cover 158. Ventilation holes 160 are provided along the top of the hood or through the grill 162 allowing scenting of the immediate area. Access to the scenting materials is possible by rotating the hood cover 158 along hinge line 164 in a manner similar to a conventional automobile engine load. Window openings 166 provide the inspection apertures for determining the amount of tissue paper stored within the interior chamber.
It is to be understood that while I have illustrated and described certain forms of my invention, it is not to be limited to the specific forms or arrangement of parts herein described and shown. It will be readily apparent to those skilled in this 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.
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A tissue paper storage and scenting apparatus having an interior chamber sized to accommodate from multiple rolls of tissue paper in a sealed environment ventilated through an upper portion of the apparatus which is receptive to fragrance producing materials. The tissue paper is maintained in a highly fragrant environment so as to provide a scent to the stored tissue rolls while preventing unwanted bathroom odors from spoiling the tissue paper. The instant invention further provides for scenting of the bathroom environment thereby forming a combination storage container and scenting mechanism that can be placed on a counter or along the floor providing ease of access to a bathroom guest.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of Korean Patent Applications No. 2008-0104468 filed on Oct. 23, 2008 and No. 2009-0045995 filed on May 26, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a ceramic laminate and a method of manufacturing a ceramic sintered body.
[0004] 2. Description of the Related Art
[0005] In general, multilayer ceramic substrates have been used as components on which active elements, such as semiconductor IC chips, and passive elements, such as capacitors, inductors and resistors, are mounted. Also, multilayer ceramic substrates have simply been used in semiconductor IC packages. Specifically, these multilayer ceramic substrates have been widely used to construct various electronic components including PA module substrates, RF diode switches, filters, chip antennas, various package components and complex devices.
[0006] In order to manufacture the above-described multilayer ceramic substrates, dielectric sheets having wiring conductors formed thereon are laminated, and the sintering process is necessarily performed on the laminate to achieve optimum characteristics. However, after this sintering process is performed, the multilayer ceramic substrates shrink because ceramics are sintered. Since multilayer ceramic substrates do not shrink evenly in all directions, dimensional changes occur in the planar direction of ceramic layers. The shrinkage of the ceramic substrate in the planar direction also causes undesirable deformations or distortions. Specifically, the accuracy of external electrodes for connections with chip components, which are mounted onto multilayer ceramic substrates, may be reduced or wiring conductors may be disconnected.
[0007] The shrinkage of the ceramic substrate in the planar direction causes a misalignment between conductor patterns and the ceramic substrate when mounting components. As a result, it may be impossible to mount semiconductor chips, such as chip size packages (CSPs) and MCM (multi-chip modules), with high accuracy. Therefore, there has been proposed a so-called non-shrinking method in order to remove shrinkage in the planar direction in a sintering process when multilayer ceramic substrates are manufactured.
[0008] According to a general non-shrinking method, constraining sheets are formed using alumina powder, which is a ceramic that is not sintered at 900° C. or less, the formed constraining sheets are laminated on the top and bottom of low temperature co-fired ceramic (LTCC) dielectric sheets to form a ceramic substrate, a predetermined weight is applied to the ceramic substrate to perform plasticizing and sintering, and then the constraining sheets are removed therefrom, thereby obtaining a ceramic substrate. FIG. 1 is a cross-sectional view illustrating one process of a general non-shrinking method of manufacturing a ceramic substrate. Constraining layers 11 are disposed on the top and bottom of a ceramic laminate 10 that has a plurality of ceramic sheets laminated onto one another. Here, each of the constraining layers 11 is not sintered at a sintering temperature of the ceramic laminate 10 . The constraining layers 11 can prevent shrinkage in the planar direction of the ceramic laminate 10 during the sintering process.
[0009] However, in the non-shrinking method, illustrated in FIG. 1 , a large constraining force is applied to ceramic sheets adjacent to the constraining sheets 11 , but a relatively small constraining force is applied to the inner part of the ceramic laminate 10 . Since the constraining force is unevenly applied to the ceramic laminate 10 , a stress imbalance occurs in the inner part of the ceramic laminate 10 . As a result, the reliability of the ceramic substrate may be deteriorated. This problem may be worsened when the ceramic laminate 10 is thick.
SUMMARY OF THE INVENTION
[0010] An aspect of the present invention provides a ceramic laminate having constraining layers that can evenly exert a constraining force onto a ceramic laminate during sintering.
[0011] Another aspect of the present invention provides a method of manufacturing a ceramic sintered body that is obtained by sintering the ceramic laminate.
[0012] According to an aspect of the present invention, there is provided a ceramic laminate including: at least one ceramic sheet having first ceramic particles and glass particles; and at least one constraining sheet having second ceramic particles and alternating with the ceramic sheet while the constraining sheet and the ceramic sheet are in contact with each other, wherein the glass particles and the first ceramic particles each have a larger particle size than the second ceramic particles, and the first ceramic particles have a particle size of 1 μm or more, the glass particles have a particle size within the range of 1 μm to 10 μm, and the second ceramic particles have a particle size of 1 μm or less.
[0013] The ceramic sheet and the constraining sheet may each include a conductive pattern and a conductive via.
[0014] The ceramic sheet may have a thickness within the range of 20 μm to 200 μm.
[0015] The constraining sheet may have a thickness of 20 μm or less.
[0016] The ceramic sheet may be thicker than the constraining sheet.
[0017] The first and second ceramic particles may be formed of the same material.
[0018] The constraining sheet may include the second ceramic particles and organic binders.
[0019] The glass particles may include a composition represented by (Ca, Sr, Ba)O—Al 2 O 3—SiO 2 —ZnO—B 2 O 3 .
[0020] The first ceramic particles may include Al 2 O 3 .
[0021] The ceramic sheet may include 40 to 80 wt % of the glass particles and 20 to 60 wt % of the first ceramic particles.
[0022] The glass particles include 2 to 10 wt % of ZnO.
[0023] According to another aspect of the present invention, there is provided a method of manufacturing a ceramic sintered body, the method including: preparing at least one ceramic sheet having first ceramic particles and glass particles; preparing at least one constraining sheet having second ceramic particles having a smaller particle size than the glass particles and the first ceramic particles; forming a ceramic laminate by alternating the ceramic sheet and the constraining sheet while the ceramic sheet and the constraining sheet are in contact with each other; and sintering the ceramic laminate so that components, which do not react with the first ceramic particles, from the glass particle are moved into the constraining sheet to sinter the constraining sheet when the ceramic sheet is sintered.
[0024] The constraining sheet may be sintered after the ceramic sheet is sintered.
[0025] The constraining sheet may be sintered at the sintering temperature of the ceramic sheet.
[0026] The glass particles may include a composition represented by (Ca, Sr, Ba)O—Al 2 O 3 —SiO 2 —ZnO—B 2 O 3 .
[0027] The first ceramic particles may include Al 2 O 3 .
[0028] The ceramic sheet may include 40 to 80 wt % of the glass particles and 20 to 60 wt % of the first ceramic particles.
[0029] The glass particles may include 2 to 10 wt % of ZnO.
[0030] Components, which do not react with the first ceramic particles, may include ZnO.
[0031] The first ceramic particles may have a particle size of 1 μm or more, the glass particles may have a particle size within the range of 1 μm to 10 μm, and the second ceramic particles may have a particle size of 1 μm or less.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0033] FIG. 1 is a cross-sectional view illustrating one process of a general non-shrinking method of manufacturing a ceramic substrate;
[0034] FIG. 2 is a cross-sectional view illustrating a ceramic laminate according to an exemplary embodiment of the invention;
[0035] FIG. 3 is a detailed view illustrating a ceramic sheet and a constraining sheet of the ceramic laminate, shown in FIG. 2 ;
[0036] FIG. 4 is an enlarged view illustrating particles constituting a ceramic sheet and a constraining sheet; and
[0037] FIG. 5 is an enlarged view illustrating particles constituting a ceramic sheet and a constraining sheet.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The invention may however be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the shapes and dimensions may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like components.
[0039] FIG. 2 is a cross-sectional view illustrating a ceramic laminate according to an exemplary embodiment of the invention. FIG. 3 is a detailed view illustrating a ceramic sheet and a constraining sheet of the ceramic laminate, shown in FIG. 2 . First, referring to FIG. 2 , a ceramic laminate 100 according to this embodiment includes ceramic sheets 101 and constraining sheets 102 . The ceramic sheets 101 and the constraining sheets 102 alternate with each other while they are bonded to each other. The ceramic sheets 101 may be formed using glass, ceramic fillers and organic binders by the doctor blade method known in the related art. The constraining sheets 102 include glass ceramic fillers and organic binders and a very small amount of glass so that the constraining sheets 102 cannot be sintered at the sintering temperature of the ceramic sheets 101 . These constraining sheets 102 can exert a constraining force onto the ceramic sheets 101 during sintering.
[0040] As described above, unlike the related art, in the ceramic laminate 100 , each of the constraining sheets 102 is disposed between the ceramic sheets 101 . The constraining sheets 102 remain in the final device, that is, a ceramic sintered body. To this end, as shown in FIG. 3 , conductive patterns 103 and conductive vias 104 may be provided in the ceramic sheets 101 and the constraining sheets 102 .
[0041] As the constraining sheets 102 are in contact with the top and bottom of each of the ceramic sheets 101 , the constraining force can be evenly exerted onto the ceramic sheets 101 to thereby prevent a stress imbalance. Furthermore, since the constraining sheets 102 do not need to be removed after the sintering process, processing convenience can be significantly increased. As it will be described below, even though glass particles are moved within the constraining sheets 102 during the sintering process, an excessive volume of the constraining sheets 102 having a high proportion of ceramic fillers may deteriorate properties of a ceramic sintered body after the sintering process, that is, a ceramic substrate. Therefore, the above-described constraining sheet may have a thickness t 2 of 20 μm or less, preferably, 10 μm or less. The ceramic sheet 101 has a thickness t 1 within the range of 20 μm to 200 μm.
[0042] As described above, the constraining sheets 102 include ceramic fillers that are not sintered at the sintering temperature of the ceramic sheets 101 . However, as the ceramic sheets 101 start to be sintered, the constraining sheets 102 may also be sintered at a relatively low temperature. This will be described with reference to FIGS. 4 and 5 . FIGS. 4 and 5 are views enlarging particles constituting a ceramic sheet and a constraining sheet. Here, in FIG. 4 , the ceramic laminate 100 , shown in FIG. 2 , is kept at a temperature less than the sintering temperature, and in FIG. 5 , glass particles are being moved during the sintering process. During the sintering process of the ceramic sheets 101 , when the constraining sheets 102 are not sintered, and then start to be sintered at a temperature much higher than the sintering temperature of the ceramic sheets 101 , the sintering state of the ceramic sheets 101 , which have already been sintered, may be deteriorated. Considering this, in this embodiment, glass particles are moved into the constraining sheets 102 while the ceramic sheets 101 are sintered.
[0043] If glass particles G, partially constituting the ceramic sheets 101 , are moved into the constraining sheets 102 during the sintering process, the sintering temperature of the constraining sheets 102 is gradually reduced, and thus the constraining sheets 102 may be sintered at a temperature close to the sintering temperature of the ceramic sheets 101 . Therefore, the ceramic sintered body can be obtained in which the ceramic laminate 100 is evenly sintered. To this end, a diameter D 1 of each of the glass particles G and a diameter D 3 of each of the ceramic particles (first ceramic particles C 1 ) constituting the ceramic fillers that are included in the ceramic sheets 101 need to be larger than a diameter D 2 of each of the ceramic particles (second ceramic particles C 2 ) that are included in the constraining sheets 102 . As shown in FIG. 5 , this helps to promote the movement of the glass particles G by capillary action. Specifically, the particle diameter D 1 of each of the glass particles G may be within the range of 1 μm to 10 μm, preferably, around 2.5 μm. The first ceramic particles C 1 may be of similar size to the glass particles G in terms of sintering characteristics. Preferably, the particle diameter D 3 of the ceramic particle may be 1 μm or more. Considering this, the particle diameter D 2 of the second ceramic particle C 2 may be 1 μm. Here, since the plurality of glass particles G and the first and second ceramic particles C 1 and C 2 exist, the particle diameter can be defined as a mean particle diameter.
[0044] Since the glass penetrates into the constraining sheets 102 during the sintering process, the second ceramic particles C 2 , included in the constraining sheets 102 , are preferably formed of a material that has relatively higher wettability with respect to the glass of the ceramic sheets 101 . The same applies to the first ceramic particles C 1 . When unreacted glass materials remain among the glass particles G during the sintering process, these unreacted glass materials may be easily moved into the constraining sheets 102 . Considering these factors, the glass particles G may be formed of a composition represented by (Ca, Sr, Ba)O—Al 2 O 3 —SiO 2 —ZnO—B 2 O 3 , and the first ceramic particles C 1 may be formed of Al 2 O 3 . Here, the glass particles G and the first ceramic particles C 1 are mixed while the glass particles G are added at a ratio of 40 to 80 wt % of (Ca, Sr, Ba)O—Al 20 3 —SiO 2 and the first ceramic particles C 1 are added at a ratio of 20 to 60 wt % of Al 2 O 3 with respect to the ceramic sheets 101 .
[0045] During the sintering process, glass, containing large amounts of Zn and B, is introduced into the constraining sheets 102 from the ceramic sheets 101 . Here, as described, the glass, introduced into the constraining sheets 102 , is left without making a reaction to the first ceramic particles C 1 . The glass, introduced into the constraining sheets 102 , results in a pore-free interface between the ceramic sheets 101 and the constraining sheets 102 . Specifically, during the sintering process, when (Ca, Sr, Ba)O—Al 2 O 3 —SiO 2 -based glass reacts with Al 2 O 3 , (Ca, Sr, Ba)Al 2 Si 2 O 8 , unreacted glass components are obtained. In the above reaction, ZnO mostly becomes unreacted glass components. Here, a crystal of (Ca, Sr, Ba)Al 2 Si 2 O 8 rarely contains ZnO. Crystallographically, since an ionic radius of each of the elements, such as Ca, Sr and Ba, is much larger than that of Zn, Zn is difficult to substitute for the elements. Therefore, the glass components containing large amounts of Zn are moved into the constraining sheets 102 during the sinter process of the ceramic sheets 101 . That is, glass particles G′, having moved to the constraining sheets 102 , shown in FIG. 5 , are different from the glass particles G that have existed in the ceramic sheets 101 .
[0046] The glass components containing the large amounts of Zn, having moved into the constraining sheet 102 , react with the second ceramic particles C 2 , for example, Al 2 O 3 , a crystalline phase, such as ZnAl 2 O 4 , is precipitated. As this reaction occurs, the unreacted glass in the ceramic sheet 101 is introduced into the constraining sheet 102 at a higher rate. Herein, the constraining sheets 102 are sintered. When ZnO is added to the (Ca, Sr, Ba)O—Al 2 O 3 —SiO 2 -based glass, the content of ZnO needs to be appropriately controlled. For example, SiO 2 is added at a ratio of 40 to 70 wt %, Al 2 O 3 is added at a ratio of 5 to 20 wt %, (Ca, Sr, Ba)O is added at a ratio of 10 to 35 wt %, Ba 2 O 3 is added at a ratio of 5 to 15 wt %, ZnO is added at a ratio of 2 to 10 wt % by weight of the glass particles G. When the ZnO content is 2 wt % or higher, this ensures high fluidity of the glass of the ceramic sheet 101 , and thus, the remaining space of the ceramic sheets 101 after glass is introduced into the constraining sheets 102 can be filled with the glass. However, when the amount of ZnO increases considerably, basic properties of the LTCC materials, including strength, chemical resistance and insulation, may be adversely affected. Therefore, the content of ZnO does not preferably exceed 10 wt %.
[0047] The inventors of this invention have carried out experiments under various conditions to find out the effects of the invention. That is, the inventors sintered ceramic laminates and measured contraction ratios, and the results are shown in Table 1 as follows.
[0000]
TABLE 1
Constraining
Ceramic sheet
layer
Particle
Particle
Fraction
Particle
Sintering
Contraction
thickness
size (G)
size (C1)
(C1)
thickness
size (C2)
temperature
ratio
1
50 μm
2.5 μm
1.7 μm
35 wt %
6.5 μm
600 nm
850° C.
0.342
2
50 μm
2.5 μm
1.7 μm
35 wt %
6.5 μm
600 nm
870° C.
0.258
3
50 μm
2.5 μm
1.7 μm
35 wt %
6.5 μm
600 nm
900° C.
0.183
4
100 μm
2.5 μm
1.7 μm
50 wt %
6.5 μm
600 nm
850° C.
0.500
5
100 μm
2.5 μm
1.7 μm
50 wt %
6.5 μm
600 nm
870° C.
0.458
6
100 μm
2.5 μm
1.7 μm
50 wt %
6.5 μm
600 nm
900° C.
0.183
7
50 μm
2.5 μm
2.5 μm
40 wt %
6.5 μm
600 nm
850° C.
0.658
8
50 μm
2.5 μm
2.5 μm
40 wt %
6.5 μm
600 nm
870° C.
0.483
9
50 μm
2.5 μm
2.5 μm
40 wt %
6.5 μm
600 nm
900° C.
0.617
10
50 μm
4.5 μm
1.7 μm
30 wt %
4.5 μm
600 nm
870° C.
0.370
11
50 μm
2.5 μm
1.7 μm
50 wt %
4.5 μm
600 nm
870° C.
0.605
12
100 μm
2.5 μm
1.7 μm
50 wt %
4.5 μm
600 nm
870° C.
0.674
13
100 μm
2.5 μm
1.7 μm
40 wt %
4.5 μm
600 nm
870° C.
0.277
14
100 μm
2.5 μm
1.7 μm
30 wt %
4.5 μm
600 nm
870° C.
0.342
15
100 μm
2.5 μm
1.7 μm
40 wt %
5.5 μm
500 nm
870° C.
0.340
16
100 μm
2.5 μm
1.7 μm
30 wt %
5.5 μm
500 nm
870° C.
0.407
[0048] Sample Nos. 1 to 3 are glass for ceramic sheets, which is formed of Ca—Al—Si—O glass. Sample Nos. 4 to 6 and 11 to 16 are formed of Ca—Al—Si—Zn—O glass. Sample Nos. 7 to 9 are formed of Mg—Ca—Si—O glass. Sample No. 10 is formed of Ca—Al—Si—B glass.
[0049] As described above, when a non-shrinking method according to the embodiments of the invention is used, a constraining force is evenly exerted onto a ceramic laminate, and constraining sheets are naturally sintered at a temperature around the sintering temperature of ceramic sheets because of the transferral of glass particles to thereby increase sintering characteristics.
[0050] As set forth above, according to exemplary embodiments of the invention, a ceramic laminate having constraining sheets that can evenly exert a constraining force onto a ceramic subst during sintering can be provided. Further, a non-shrinking method according to exemplary embodiments of the invention allows constraining sheets to be naturally sintered at a temperature around the sintering temperature of ceramic sheets because of the transferral of glass particles to thereby increase sintering characteristics. Furthermore, since there is no need to remove constraining sheets after sintering, processing convenience can be significantly increased.
[0051] While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
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There are provided a ceramic laminate and a method of manufacturing a ceramic sintered body. A ceramic laminate according to an aspect of the invention may include: at least one ceramic sheet having first ceramic particles and glass particles; and at least one constraining sheet having second ceramic particles and alternating with the ceramic sheet while the constraining sheet and the ceramic sheet are in contact with each other, wherein the glass particles and the first ceramic particles each have a larger particle size than the second ceramic particles, and the first ceramic particles have a particle size of 1 μm or more, the glass particles have a particle size within the range of 1 μm to 10 μm, and the second ceramic particles have a particle size of 1 μm or less. An aspect of the present invention provides a ceramic laminate having constraining layers that can evenly exert a constraining force onto a ceramic laminate during sintering.
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FIELD OF THE INVENTION
The present invention relates to a latch needle for a knitting machine, in particular for a circular knitting machine. More specifically, the present invention relates to a latch needle for high speed circular knitting machines.
BACKGROUND OF THE INVENTION
Latch needles are mounted in a circular knitting machine in such a way that their backs are in contact with the needle bed in the needle grooves in the cylinder. As the cylinder rotates, the latch needles rotate at a high speed, while at the same time fixed cams established opposingly to the needle bed act on the butts of the latch needles, reciprocating the latch needles at a high speed. As the knitting speed increases, the force with which each cam acts on these needle butts also increases and is transmitted to the needle head as a shock wave, causing broken needle heads.
In an attempt to solve this problem, it has been proposed to incorporate into the needles means to absorb the shock wave that is generated and transmitted to the needle head when the cam acts on the butt. This proposal includes providing the needle trunk, which is between the butt and the needle head, with cutouts on the upper and lower sides. It has also been postulated that the thinner the needle shaft and the bridge that are left after the cutouts have been made the more effective the shock absorbing performance. This is a so-called meander-type latch needle, which is widely used today. Various and sundry other attempts at latch needles with shock absorbing capabilities have also been proposed.
In these so-called meander-type latch needles, depending on the structure of the knitting machine (for example a double knit machine employing a dial needle or a needle that is controlled by a special needle-selecting structure), there is a limit to how far the butt and the needle head can be distanced from each other, making it impossible to provide the needle trunk between the butt and the needle head with a shape that effectively absorbs the shock wave.
Another type of latch needle has been proposed based on the concept of completely blocking the shock wave, which is generated when the cam hits the butt, before it reaches the needle head. According to this concept, the shock wave is blocked by splitting the head part and the butt part, which were conventionally one unit. For example, Japanese Utility Model Application No. A-55-180788, Japanese Utility Model Application No. A-56-78896, and U.S. Pat. Nos. 2,431,635 and 3,411,327 propose this type of latch needle in one form or another. According to these utility models and patents, the working needle and the butt needle engage at the position of the butt of the butt needle or at a position closer to the front of the butt needle.
As for the latter type, i.e., the split-type latch needle, the variations disclosed in the patents and utility models mentioned above are rarely used in practice now. The reason is believed to be that none of them have produced satisfactory results.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is an object of the present invention to provide a latch needle which obviates the deficiencies and disadvantages with prior proposed shock absorbing needles. The present invention accomplishes this object by providing a latch needle split into a working needle and a butt needle and by determining, after a number of experiments, that the position at which the working needle and the butt needle engage plays an important role in the effectiveness of shock absorption.
Accordingly, a latch needle of the present invention is characterized in that it is split into a working needle having a needle head with a hook and a latch and a body portion with at least one connecting projection, and a butt needle having a body portion including at least one connecting indentation into which the connecting projection is inserted, and a butt between the hook of the working needle and the connecting projection on the working needle and the connecting indentation of the butt needle. The overall length of the working needle may vary from the first one third to roughly the entire length of the latch needle.
The butt needle of the present invention has at least one indentation into which the connecting projection is inserted and at least one butt that goes into the cam groove of the knitting machine. In practice, many latch needles have a plurality of butts that go into cam grooves of the knitting machine.
From the viewpoint of machinability, it is preferable that the connecting projection has a rectangular shape and the indentation has a shape that complements the rectangle. However, as long as they can be connected as intended, any other shape can be adopted. For example, combinations of a semicircular projection and a semicircular indentation, a triangular projection and a triangular indentation, an W-shaped curved projection and its complementary curved indentation, etc., may be employed.
It is important that the connecting projection and indentation are engaged at a position farther than the position of the butt of the butt needle from the hook of the working needle. This is one feature that differentiates the present invention from prior split-type needles cited above. In other words, the hook of the working needle, the butt of the butt needle and the connecting projection and indentation must be disposed in that order. When a plurality of butts are established, the "butt of the butt needle" refers to "the control butt that is controlled by the lowering cam in an open-type cam". The present invention is not intended to be directly applied to closed-type cams because in the case of closed-type cams, the shock wave generated by the cam acting on the butt is not as strong as in the case of open-type cams, therefore there are fewer instances of broken needle heads. In practice, however, it is definitely possible to use the needle of the present invention for closed-type cams.
Because the positions of the working needle hook, the connecting projection and indentation, and of the butt of the butt needle may vary from one latch needle to another, it is difficult to quantify the relative distances between them. Judging from the experimental results (FIGS. 7 and 8) described later, the differences of these positions seem to influence the effect of the invention only to a limited degree.
The working needle and the butt needle are simply fitted at the connecting projection and indentation, and placed in the cylinder groove of the knitting machine manually by a worker. It is preferable to fit the two needles leaving virtually no gap between the projection and the indentation. It is also preferable to provide a means for reinforcing the connection of the two so as to avoid an accident such as the two needles getting separated from each other after being placed in the groove while the knitting machine is working.
As an example of such a connection reinforcing means, an auxiliary connection may be established at a place other than the connecting projection and indentation. The auxiliary connection is most preferably established on the bridge that is the closest to the needle head, in particular on the bridge pier that is the closer to the needle head, but it could also be situated at any other appropriate place. The auxiliary connection may-consist of a fastening indentation on the working needle and a fastening projection on the butt needle, which are engaged with one another. As another connection reinforcement means, the connection may consist of parts having wedge-shaped or other non-linear-shaped longitudinal sections. Alternatively, adhesive may be used for temporary connection.
In use of the latch needle of the present invention, the shock generated when the cam hits the butt is blocked by the connecting projection and indentation, and not transmitted directly to the needle head, resulting in a reduced possibility of damaging the needle head.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the objects and advantages of the present invention having been stated, others will appear as the description proceeds when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is an elevational view of a latch needle of the present invention;
FIG. 2 is an elevational view of another embodiment of the latch needle of present invention;
FIG. 3 is an enlarged, fragmentary detail view of the portion of the latch needle contained within the circle 3 in FIG. 2;
FIG. 4 is an elevational view of a further embodiment of the latch needle of the present invention;
FIG. 5 is an enlarged, fragmentary detail view of the portion of the latch needle within the circle 5 in FIG. 4;
FIG. 6 is an enlarged, fragmentary detail view, partially in section, of the connecting means between the working needle and the butt needle of the latch needle of the present invention;
FIGS. 7A-7D are elevational views of latch needles of the present invention that were used in the experiment in which the present invention and the prior art were compared; and
FIGS. 8A-8D are elevational views of prior art latch needles used in the experiment comparing the latch needles of the present invention to latch needles of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
Referring now more specifically to the drawings and particularly to FIG. 1, there is illustrated a latch needle, generally indicated at 10, which incorporates the features of the present invention. Latch needle 10 includes a working needle, generally indicated at 20, and a butt needle, generally indicated at 30, connected together and mounted in a circular knitting machine, generally indicated at 11.
Circular knitting machine 11 includes a rotatable cylinder 12 having vertical grooves in which latch needles 10 are slidably mounted. Needle operating cams 13, only one of which is shown, are mounted on a cam block 14 and reciprocate the needles 10 as the cylinder 12 rotates.
Working needle 20 has a needle head 21 which includes a hook 21a and a pivotally mounted latch 21b. Working needle 20 also includes a body portion 22 extending downwardly from the needle head 21 to the opposite end of the working needle 20. The length of the working needle 20 may vary from about one-third to about the entire length of latch needle 10.
Connecting means 23 is carried by body portion 22 on the side thereof toward which the hook 21a faces and which faces the cam block 14 and preferably comprises at least one projection 23 which extends outwardly for a predetermined distance. The shape of the projection 23 is preferably rectangular, although other geometric shapes may be used.
Butt needle 30 includes a body portion 31 which extends the full length of butt needle 30. Body portion 31 has at least one butt 32a thereon adjacent the upper end 31a of the body portion 31. Frequently, butt needle 30 will have a plurality of butts thereon and as illustrated in FIG. 1, body portion 31 has three butts 32a, 32b and 32c thereon.
Body portion 31 preferably has cutouts in its opposite sides resulting in a so-called meander configuration and, as illustrated, has five bridges 33a, 33b, 33c, 33d and 33e thereon. Body portion 31 also has a connecting indentation 34 which receives the connecting projection 23 on working needle 20 to connect the working needle 20 and butt needle 30 together. While it is illustrated that the connecting projection 23 is on the working needle 20 and the connecting indentation is in the butt needle 30, it should be understood that the projection could be on the butt needle 30 and the indentation could be in the working needle 20.
The position of the connecting projection 23 and connecting indentation 34 is farther from the needle head 21 than the position of the butt 32a. Generally, the butt closest to the needle head is the butt that engages the needle lowering cam in an open cam track and generates the greatest shock wave. Therefore, in butt needles having more than one butt, it is the butt closest to the needle head that is of most concern and the one to which the present invention is particularly directed.
Referring now to FIGS. 2 and 3, there is illustrated another embodiment of the present invention in which like parts are referred to by like reference characters with a prefix "1" added thereto. Latch needle 110 includes a working needle 120 and a butt needle 130 which are connected by a connecting projection 123 and indentation 134. Butt needle 130 includes butts 132a, 132b and 132c.
Latch needle 110 differs from latch needle 10 in that it includes an auxiliary connecting means 140. As illustrated, auxiliary connecting means 140 includes a fastening projection 141 on the working needle 120 and a fastening indentation 142 in the upper end 131a of the body portion 131 of butt needle 130. When the fastening projection 141 is received in the fastening indentation 142, the connection of working needle 120 and butt needle 130 together is reinforced.
Referring to FIGS. 4 and 5, there is illustrated a further embodiment of the present invention in which like features are referred to by like reference characters with the prefix "2" added. Latch needle 210 is very similar to latch needle 110 except for auxiliary connecting means 240.
Latch needle 210 includes a working needle 220 having a needle head 221 and a connecting projection 223, and a butt needle 230 having butts 232a, 232b and 232c and a connecting indentation 234. Auxiliary connecting means 240 includes a fastening indentation 243 on working needle 220 and a fastening projection 244 on the upper end 231a of butt needle 230.
Referring now to FIG. 6, there is illustrated an enlarged detail of the connecting means including projection 23 on body portion 21 of working needle 20 and indentation 34 in body portion 31 of butt needle 30. As is evident, projection 23 is wedge-shaped in section and indentation 34 is correspondingly shaped. While other configurations may be used, the wedge-shape is preferred.
FIG. 7 illustrates latch needles 110 of the present invention while FIG. 8 illustrate so-called meander-type needles from the prior art. These needles were used in an idling experiment to investigate the breaking rate of each type. A type V-LPJ3B 30-inch, 18-gauge circular knitting machine manufactured by Precision Fukahara Works, Ltd. was used to perform the experiment and one hundred (100) needles of each type were placed in the cylinder. The shape of the cam used was as is disclosed in Japanese Patent Application No. A-8-49147 and the cams were set in a welt position at all yarn feeders with the stitch cams set to pull 1.75 mm. Until the total revolution count reached 100,000, the knitting machine was run at 35 rpm.
The results of the experiment are set forth in Table 1 below:
TABLE 1__________________________________________________________________________(Numerical unit in the first line is thousand;"5" means five thousand, for instance) Breaking5 10 15 20 30 40 50 60 70 80 90 100 Total rate (%)__________________________________________________________________________7A 0 0 0 0 0 0 0 0 0 0 0 0 0 07B 0 0 0 0 0 0 0 0 0 0 0 0 0 07C 0 0 0 0 0 0 0 0 0 0 0 0 0 07D 0 0 0 0 0 0 0 0 0 0 0 0 0 08A 2 12 21 11 9 6 2 2 2 0 0 1 78 788B 4 14 19 12 8 9 4 0 0 2 4 3 79 798C 3 22 13 14 5 2 0 3 0 3 3 0 68 688D 0 4 10 10 5 5 3 1 1 3 4 2 48 48__________________________________________________________________________
It is evident from this table that breakages of the needle heads can be dramatically reduced using the present invention. The present invention is also accompanied by the following effects.
In the case of the conventional type of needle, when the needle head is broken, for example, even if the butt itself is not damaged, the whole needle has to be replaced. Conversely, if the butt is broken, even if the needle head is not damaged, the whole needle has to be replaced. Whereas in the case of the needle of the present invention, if the needle head is broken, only the working needle has to be replaced, and if the butt is broken, only the butt needle has to be replaced.
In the case of the conventional type of needle, because there are many different kinds of knitting machines, different kinds of latch needles with a variety of needle shaft dimensions, shapes and butt positions have to be prepared even if their needle heads may have the same dimensions and shape. Whereas using the technique of the present invention, one type of working needle can be used in combinations with different types of butt needles, which are generally easier to make in different forms, according to the different types of needle-selecting mechanisms of the knitting machine to be used. In other words, the butt needle also functions as an adapter that interlinks the working needle and the knitting machine.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
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A latch needle is provided and includes a working needle having a needle head with a hook and a latch and a body portion having a connecting projection extending outwardly therefrom, and a butt needle having a connecting indentation therein which receives the connecting projection to connect the working needle and butt needle together and a butt thereon between the needle head of the working needle and the connecting projection and the connecting indentations. The latch needle also includes reinforcement of the connection between the working needle and the butt needle in the form of a fastening projection and a fastening indentation located between the needle head and the butt on the butt needle.
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FIELD OF THE INVENTION
The present invention is directed generally to a printing press cylinder coupling method and apparatus. More particularly, the present invention is directed to a method and apparatus for coupling a cylinder of a rotary printing press to a toothed driving wheel. Most specifically, the present invention is directed to a printing press cylinder coupling method and apparatus which uses a switchable coupling including a cylinder coupling disk and a driving wheel coupling disk. The coupling disks are engageable with each other to put the cylinder in connection with the toothed driving wheel in a positive, torsion-proof connection. One of the coupling disks is movable axially toward and away from the other to accomplish this positive coupling. A pressurized medium is utilized to accomplish the axial shifting of one of the disks with respect to the other. A rise in pressure in the pressurized medium in a work cylinder is used to indicate the completion of the coupling of the cylinder to the toothed driving wheel.
DESCRIPTION OF THE PRIOR ART
In the field of rotary printing, it is frequently desirable to be able to effect the coupling and the uncoupling of a cylinder to a drive assembly, such as a toothed driving wheel or gear. Such a coupling must be a positive one to insure that there will be no slippage or relative movement, but should also be one that is quickly and easily uncoupled.
In the German Utility Model DE Gbm 1 858 031 there is disclosed a device that is usable to accomplish the coupling of a cylinder of a rotary printing press to a toothed driving wheel. In this prior art device, the cylinder crown or barrel is provided with a first coupling disk that is pressed against a second, axially adjustable coupling disk. A work cylinder is used to accomplish the axial shifting of the axially adjustable coupling disk. This axially adjustable coupling disk is rigidly or securely connected with the toothed driving wheel.
A limitation of this prior art device is that it is not easy to accomplish the uncoupling of the cylinder crown or barrel from the toothed driving wheel. The cylinder crown must be disassembled in order to effect this disconnection. Such a coupling device will not satisfy the need for a coupling that is operable in a rapid manner.
It is clear that a need exists for a printing press cylinder coupling device that overcomes the limitations of the prior art. The device for coupling a cylinder in accordance with the present invention provides such a device and is a significant advance over the prior art.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a printing press cylinder coupling method and device.
Another object of the present invention is to provide a method and a device for coupling a cylinder of a rotary printing press to a toothed driving wheel.
A further object of the present invention is to provide a printing press cylinder coupling that uses a switchable coupling.
Still another object of the present invention is to provide a device for coupling a cylinder of a rotary printing press which is not subject to substantial wear.
Yet a further object of the present invention is to provide a printing press cylinder coupling that uses a cylinder coupling disk and a driving wheel coupling disk.
Even still another object of the present invention is to provide a coupling device in which a pressure medium is used to effect the coupling.
As will be set forth in detail in the description of the preferred embodiment which is presented subsequently, the printing press cylinder coupling method and device in accordance with the present invention utilizes a cylinder coupling disk and a driving wheel coupling disk. The two disks have cooperable spur teeth on their adjacent side faces. These spur teeth are engageable with each other in only one position and effect a secure coupling of the cylinder to the driving gear wheel when the disks are brought into contact. One of the two coupling disks is axially shiftable toward and away from the other disk by application of a pressure medium to a work cylinder. A control valve is carried by the axially slidable disk and provides a bleed passage for the pressure medium. This bleed passage stays open until the two disks are securely coupled. Once the two disks have been brought into their securely coupled position, the bleed passage is closed. This creates an increase in pressure in the work cylinder with the increase in pressure being usable as an indication that a secure coupling has been effected. The two pressures in the cylinder are measured by a manometric switch that is placed in the pressure medium supply line.
The cylinder coupling method and device of the present invention provides for the accomplishment of a gentle, low wear coupling between the two coupling disks. The axially shiftable disk is moved into secure coupling contact with the fixed position disk by the application of the pressure medium at a relatively reduced pressure because of the provision of the bleed passage in the control valve. Once the secure coupling of the two disks has been accomplished, the bleed passage will close. This will then allow the full force of the pressure medium to be applied against the axially shiftable coupling disk by the working chamber. At this point, there is no axial movement between the two coupling disks so that the full pressure medium force is used only to hold the two coupling disks in place in their coupled position.
A pressure gauge, such as a manometer that is provided with a switch, is placed in the pressure medium supply line. The pressure sensed in the work cylinder by the manometer will increase once the secure coupling has been fully accomplished. As this increased pressure is sensed, the manometric switch can issue an electrical control signal that can be used to initiate other pressure operations. The use of the manometer and its associated switch eliminates problems caused by oil mist or the transmission of data from a rotating or axially displaceable element.
The control valve which is carried by the axially shiftable coupling disk, and which provides the bleed passage for the pressure medium until a complete coupling has been accomplished, is a small, uncomplicated structure. It is actuated directly by contact between the two coupling disks. The bleed passage is formed as an annular space between a slidable control piston and a slidable pressure sleeve. The size of this annular gap is easily set during manufacture of the control valve. The pressure sleeve that forms the bleed passage, also serves as a guide for the sliding movement of the control piston. As the two disks are brought into their fully coupled positions by axial movement of one disk with respect to the other, the pressure sleeve is caused to slide in the housing of the control valve and causes the control piston to move against the force of the pressure medium and to thereby close the bleed passage. This closure of the bleed passage gives rise to the increase in pressure in the cylinder chamber of the work cylinder and thus provides a signal that the coupling has been accomplished.
The printing press cylinder coupling assembly in accordance with the present invention overcomes the limitations of the prior art devices. It is a substantial advance in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the printing press cylinder coupling in accordance with the present invention are set forth with particularity in the appended claims, a full and complete understanding of the invention may be had by referring to the detailed description of the preferred embodiment which is presented subsequently, and as illustrated in the accompanying drawings, in which:
FIG. 1 is a schematic cross-sectional view of a preferred embodiment of the printing press cylinder coupling in accordance with the present invention and showing the device in its uncoupled position; and
FIG. 2 is a schematic cross-sectional view of the control valve portion of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, there may be seen a cylinder trunnion or journal 1 that is typically positioned at the end of a cylinder which is used in a rotary printing press. Only the cylinder journal or pin 1 is depicted in FIG. 1 of the drawings. It will be understood that the cylinder, of which cylinder journal or pin 1 is a part, is not depicted in the drawings, since it is generally conventional and forms no part of the present invention. Similarly, the rotary printing press, in which the cylinder that includes cylinder journal 1, operates, is not shown in the drawings since it is of generally well known construction.
As may be seen in FIG. 1, the cylinder journal 1 can be connected with a toothed driving wheel, generally at 3, by means of a switchable coupling, generally at 2. This switchable coupling utilizes a cylinder coupling disk 4 and a driving wheel coupling disk 6. Both of these coupling disks 4 and 6 are generally similar in overall shape and have spur teeth 7 and 8, respectively on their, generally planar, facing side surfaces, as seen in FIG. 1. These spur teeth 7 and 8 are matched to each other and have a cooperating pattern which will allow them to matingly engage only when the coupling disks 4 and 6 are in one defined rotational position with respect to each other. This means that the coupling 2 is structured as a so-called one value or single position coupling. In one possible configuration, the coupling disk 4 could be provided with one or two spur teeth 7 that are of different shapes or widths than the other ones of the spur teeth 7. For example, one or more of these spur teeth could be broader than the others. A corresponding one or ones of the spur teeth 8 on the driving wheel disk 6 could be provided with gaps or spacings between themselves that correspond to these broader teeth. This will insure that the spur teeth 7 and 8 are engageable only when the two coupling disks 4 and 6 are in their desired rotational positions.
In the preferred embodiment of the printing press cylinder coupling device of the present invention, the coupling disk 4 is rigidly connected with the cylinder journal 1. This cylinder coupling disk 4 is located generally adjacent the cylinder crown or barrel and is also positioned generally adjacent a toothed gear wheel 9 that would be used to drive other cylinders, not shown, or to drive an inking unit or a similar piece of equipment. The cylinder coupling disk 4 and the toothed gear wheel 9 are secured to the cylinder journal 1 by the provision of a suitable key 11. The cylinder, together with the cylinder coupling disk 4 and the toothed gear wheel 9 are shiftable in the axial direction in a generally conventional manner. Such limited axial shifting of the cylinder may be necessary to properly set the side register.
The driving wheel coupling disk 6 is connected in a torsion-proof but axially shiftable manner to the toothed driving wheel 3. For this purpose, the driving wheel coupling disk 6 has outer teeth 12 of a width b12, for example b12=18 mm, on its circumference. These teeth 12 engage inner teeth 13 of a width b13, for example b13=40 mm, cut into the toothed driving wheel 3. The toothed driving wheel 3 is securely fastened on a hub 14. This hub 14 has a central bore 16 matched in size to the cylinder journal 1, so that the hub 14, together with the toothed driving wheel 3 which is carried by the hub 14, is seated rotatably and axially displaceable on the cylinder journal 1.
The axial displacement of the cylinder journal 1 and hence of the cylinder, which is used for setting the side register of the cylinder, is performed by means of an axially displaceable spindle 17, which is seated in the cylinder journal 1. This spindle 17 is connected with a register setting device, not shown, and is rigidly connected with the toothed driving wheel 3 by a disk 18, all as may be seen in FIG. 1. The cylinder journal 1 is thus axially shiftable with respect to the hub 14 to the extent necessary to effect proper side register of the cylinder.
A work cylinder 19 is flanged to the hub 14 which carries the toothed driving wheel 3. The work cylinder 19 has a ring-shaped or annular, axially displaceable piston 21, which acts on a generally cylinder-shaped array of pressure elements 22. A plurality, for example eight, of these pressure elements 22 are seated evenly in the circumferential direction, in bores 23 formed in the hub 14. These pressure elements 22 are connected with the driving wheel coupling disk 6 by means of screws 24. On their ends cooperating with the annular, displaceable piston 21, the pressure elements 22 are provided with collars 26. Pressure springs depicted schematically at 27 and acting on the pressure elements 22 are arranged between these collars 26 and a planar side face of the hub 14 opposite to the toothed driving wheel 3.
A rotary inlet 28 is connected with the work cylinder 19 and supplies a cylinder chamber 31 in the work cylinder 19 with a suitable pressure medium through a bore 29. A, for example electrical-pneumatic manometric switch, generally at 30, is provided in a feed line 32 for the rotary inlet 28, and whose switch point is set to 5 bar, for example. Via a bore 33 cut into the piston 21, the cylinder chamber 31 is connected with a line 34 which, in turn, is connected with a control valve 36. The control valve 36, which is shown in detail in FIG. 2, is fixedly installed in the axially shiftable, driving wheel coupling disk 6 and intermittently cooperates with the fixed, cylinder coupling disk 4 in a manner which will now be discussed in greater detail.
Referring now primarily to FIG. 2, it will be seen that control valve 36 essentially consists of a housing 37, a control piston 38, a pressure spring 39 and a pressure sleeve 41. The housing 37 is provided on its inlet end with an inlet or first bore 42, a first end of which receives the pressure medium line 34 from the piston bore 33, and whose second end has a cone-shaped flair or depression 43. A second, continuous bore 44 of an interior diameter d44, for example d44=6.5 mm, is connected in the longitudinal direction with this inlet bore 42. The control piston 38 is disposed in this continuous bore 44 and is movable in the longitudinal direction in bore 44. This control piston 38 has a cone-shaped sealing head 46 on its first end. This cone-shaped sealing head 46 is provided with an annularly extending groove 47 for receiving a seal ring 48 such as, for example, an O-ring. A control piston shaft 49 of a diameter d49, for example d49=3 mm, extends from this cone-shaped sealing head 46 and is sized and utilized to receive the pressure spring 39. This pressure spring 39 presses with its first end against an underside 51 of the sealing head 46, and with its second end against an upper or interior front face 52 of the pressure sleeve 41. The pressure sleeve 41 has a bore 53 of a diameter d53, for example d53=3.5 mm, which extends in the longitudinal direction. The bore 53 of the pressure sleeve 41 and the shaft 49 of the control piston 38 form an annular gap or bleed passage 54. An outer diameter D41, for example D41=6.4 mm, of the pressure sleeve 41 is adapted, in the area of a pressurized sleeve shoulder 56, to the interior diameter d44 of the continuous bore 44 in the housing 37 in such a way that the pressure sleeve 41 is seated so that it can be displaced in the longitudinal direction. A front interior face 58 of a detent sleeve 59, which is fastened in the continuous bore 44 of the housing 37 for limiting the travel of the pressure sleeve 41, intermittently cooperates with a lower front face 57 of the shoulder 56. A lower exterior face 61 of the pressure sleeve 41 projects out of the housing 37. The pressure sleeve 41 can thus slide in the continuous bore 44 of the housing 37 between a fully extended position in which the lower front face 57 of the pressure sleeve shoulder 56 abuts the interior face 58 of the detent sleeve 59, and a fully retracted position in which the lower exterior face 61 of the pressure sleeve 41 is flush with the end of the housing 37. The pressure sleeve 41 is urged towards its extended position by the action of the control piston pressure spring 39.
In the preferred embodiment of the printing press cylinder coupling depicted in FIG. 1, the control valve 36 is positioned in the axially shiftable coupling disk 6 that is associated with the toothed driving wheel 3. When the two coupling disks 4 and 6 are in engagement with each other to effect a coupling of the cylinder to the driving wheel 3, the lower exterior face 61 of the pressure sleeve 41 is in contact with the fixed coupling disk 4 intermediate cooperating spur teeth 7 and 8.
The operation of the printing press cylinder coupling assembly in accordance with the present invention will now be discussed in detail. In a disengaged position of the coupling 2, as is depicted in FIG. 1, the cylinder chamber 31 of the work cylinder 19 is not charged with a pressure medium. Therefore, the pressure springs 27 push the annular piston 21 toward the right through the pressure elements 22 and at the same time pull the axially shiftable driving wheel coupling disk 6 along the inner teeth 13 of the driving wheel 3, to move the spur teeth 8 out of engagement with the spur teeth 7 of the fixed, cylinder coupling disk 4 until both coupling disks, 4 and 6, are out of engagement. In the process, the exterior face 61 of the pressure sleeve 41 of the control valve 36 loses contact with the fixed coupling disk 4, so that the pressure sleeve 41 is pressed against the detent sleeve 59 by the pressure spring 39 until it is in its fully extended position, at which time the pressure spring 39 is relaxed. To accomplish the coupling of the cylinder with the driving wheel 3, a suitable pressure medium is supplied to the work cylinder 19 through the rotary inlet 28 from the feed line 32 and the manometric switch 30. This pressure medium also flows to the control valve 36 through the line 34 and by means of the increasing pressure, pushes the cone-shaped sealing head 46 of the control piston 38 away from the cone-shaped flair or depression 43, so that pressure medium flows through a resulting angular gap. This pressure medium escapes to the outside through the annular gap or bleed passage 54 formed by the control piston 38 and the pressure sleeve 41. This annular gap or bleed passage 54 and the amount of pressure medium supplied to the work cylinder 19 are matched to each other in such a way that a first, coupling shifting, pressure p1 is created in the work cylinder 19, and the two coupling disks 4 and 6 are pressed into engagement with each other by the pressure elements 22. With the control valve 36 opened during the engagement process, a value of the first, coupling shifting pressure p1, for example p1=3.5 bar, is less than a final, engaged pressure p2, for example p2=6 bar, with the control valve 36 closed, when the disks 4 and 6 are in the engaged state. The value of the pressure p1 preferably is 1/3 to 2/3 of the final pressure p2. The supplied amount of pressure medium is metered for this, for example by means of a throttle, not shown.
With the control valve 36 still opened, the cylinder is rotated by an auxiliary driving device, not shown, so that the two coupling disks 4 and 6, which are pressed against each other, turn with respect to each other. During this process, the pressure sleeve 41 of the control valve 36 does not contact the axially fixed coupling disk 4, and the control valve 36 remains open. Once the two coupling disks 4 and 6 reach their defined engagement position, the two sets of spur teeth 7 and 8 are engaged with each other. Now the axially fixed coupling disk 4 presses against the exterior face 61 of the pressure sleeve 41 of the control valve 36 and slides sleeve 41 into the housing 37. This, in turn, puts the pressure spring 39, which cooperates with pressure sleeve 41, under tension. This pressure spring 39 which is now under tension, and whose pressure force is greater than a force acting on the control piston 38 by means of the pressure medium, pushes the control piston 38 against the flair or depression 43 in the housing 37, and the annular gap between the sealing head 46 and the depression 43 is thereby closed. The control valve 36 is thus closed, so that pressure medium cannot escape through the bleed passage 54 anymore, because of which the final pressure p2 is set in the work cylinder 19. The manometric switch 30 in the feed line 32 to the rotary inlet 28 is switched because of the pressure increase and issues an electrical signal which is used for further control of the press.
Instead of the directly mechanically actuated control valve 36, it would be possible to utilize an electromagnetic valve, for example. Such an electromagnetic valve 36 could be controlled by a sensor which would sense the position of the axially shiftable coupling disk 6 and could close the control valve 36 when the axially shiftable disk 6 was in an engaged position.
While a preferred embodiment of a printing press cylinder coupling device in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that a number of changes in, for example, the overall size of the cylinder journal, the source of the pressure medium, the type of printing press in which the coupling is used, and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the following claims.
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A cylinder in a rotary printing press is coupled to a driving wheel or gear by the engagement of two coupling disks. One of the disks is shiftable into coupling engagement with the other disk by application of a pressure medium to a work cylinder. A control valve is carried by the shiftable disk and limits the force of the pressure medium by use of a bleed passage that is closed only when coupling has been accomplished. The force of the pressure medium is at a higher level when coupling has been fully completed.
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PRIORITY CLAIM
This application is a divisional of and claims the benefit of U.S. patent application Ser. No. 10/382,239 filed Mar. 5, 2003, which is a continuation-in-part of the US national phase designation of International application PCT/EP02/07162 filed Jun. 28, 2002, the contents of which are expressly incorporated herein by reference thereto.
BACKGROUND
The present invention relates to a novel carboxypeptidase gene and the polypeptide encoded thereby. In particular, the present invention relates to the use of the present carboxypeptidase in the manufacture of cocoa flavor and/or chocolate.
It is known that in processing cacao beans the generation of the typical cocoa flavor requires two steps: a fermentation step, which includes air-drying of the fermented material, and a roasting step.
During fermentation, two major activities may be observed. First, the pulp surrounding the beans is degraded by micro-organisms with the sugars contained in the pulp being largely transformed to acids, especially acetic acid (Quesnel et al., J. Sci. Food. Agric. 16 (1965), 441-447; Ostovar and Keeney, J. Food. Sci. 39 (1973), 611-617). The acids then slowly diffuse into the beans and eventually cause an acidification of the cellular material. Second, fermentation also results in a release of peptides exhibiting differing sizes and a generation of a high level of hydrophobic free amino acids. This latter finding led to the hypothesis that proteolysis occurring during the fermentation step is not due to a random protein hydrolysis, but seems to be rather based on the activity of specific endoproteinases (Kirchhoff et al., Food Chem 31 (1989), 295-311). This specific mixture of peptides and hydrophobic amino acids is deemed to represent cocoa-specific flavor precursors.
Until now several proteolytic enzyme activities have been investigated in cacao beans and studied for their putative role in the generation of cocoa flavor precursors during fermentation.
An aspartic endoproteinase activity, which is optimal at a very low pH (pH 3.5) and inhibited by pepstatin A, has been identified. A polypeptide described to have this activity has been isolated and is described to consist of two peptides (29 and 13 kDa) which are deemed to be derived by self-digestion from a 42 kDa pro-peptide (Voigt et al., J. Plant Physiol. 145 (1995), 299-307). The enzyme cleaves protein substrates between hydrophobic amino acid residues to produce oligopeptides with hydrophobic amino acid residues at the ends (Voigt et al., Food Chem. 49 (1994), 173-180). The enzyme accumulates with the vicilin-class (7S) globulin during bean ripening. Its activity remains constant during the first days of germination and does not decrease before the onset of globulin degradation (Voigt et al., J. Plant Physiol. 145 (1995), 299-307).
Also, a cysteine endoproteinase activity had been isolated which is optimal at a pH of about 5. This enzymatic activity is believed not to split native storage proteins in ungerminated seeds. Cysteine endoproteinase activity increases during the germination process when degradation of globular storage protein occurs. To date, no significant role for this enzyme in the generation of cocoa flavor has been reported (Biehl et al., Cocoa Research Conference, Salvador, Bahia, Brasil, 17-23 Nov. 1996).
Moreover, a carboxypeptidase activity has been identified which is inhibited by PMSF, and thus belongs to the class of serine proteases. It is stable over a broad pH range with a maximum activity at pH 5.8. This enzyme does not degrade native proteins, but preferentially splits hydrophobic amino acids from the carboxy-terminus of peptides (Bytofet at., Food Chem. 54 (1995), 15-21).
During the second step of cocoa flavor production, the roasting step, the oligopeptides and amino acids generated at the stage of fermentation are obviously subjected to a Maillard reaction with reducing sugars present in fermented beans, eventually yielding substances responsible for the cocoa flavor as such.
In the art, there have been many attempts to artificially produce cocoa flavor.
Cocoa-specific aroma has been obtained in experiments wherein acetone dry powder (AcDP) prepared from unfermented ripe cacao beans was subjected to autolysis at a pH of 5.2 followed by roasting in the presence of reducing sugars. It was conceived that under these conditions preferentially free hydrophobic amino acids and hydrophilic peptides should be generated and the peptide pattern thus obtained was found to be similar to that of extracts from fermented cacao beans. An analysis of free amino acids revealed that Leu, Ala, Phe and Val were the predominant amino acids liberated in fermented beans or autolysis (Voigt et al., Food Chem. 49 (1994), 173-180). In contrast to these findings, no cocoa-specific aroma could) be detected when AcDP was subjected to autolysis at a pH of as low as 3.5 (optimum pH for the aspartic endoproteinase). Only few free amino acids were found to be released, but a large number of hydrophobic peptides were formed. When peptides obtained after the autolysis of AcDP at a pH of 3.5 were treated with carboxypeptidase A from porcine pancreas at pH 7.5, hydrophobic amino acids were preferentially released. The pattern of free amino acids and peptides was similar to that found in fermented cacao beans and to the proteolysis products obtained by autolysis of AcDP at pH 5.2. After roasting of the amino acids and peptides mixture as above, a cocoa aroma could be generated.
It has also been shown that a synthetic mixture of free amino acids alone, with a similar composition to that of the spectrum found in fermented beans, was incapable of generating cocoa aroma after roasting, indicating that both the peptides and the amino acids are important for this purpose (Voigt et al., Food Chem. 49 (1994), 173-180.
In view of the above data, a hypothetical model for the generation, during fermentation, of the said mixture of peptides and amino acids, i.e. the cocoa flavor precursors, had been devised ( FIG. 1 ), where in a first step peptides having a hydrophobic amino acid at their end, are formed from storage proteins, which peptides are then further degraded to smaller peptides and free amino acids. To produce the said peptides having C-terminal hydrophobic amino acids, an aspartic endoproteinase activity related to that mentioned above seems to be involved. Yet, for splitting off hydrophobic amino acids from peptides formed in the preceding step the only known enzymatic activity, which might be considered in this respect, is that of a carboxypeptidase. However, such enzyme has not been isolated and studied in detail in cacao, and it is therefore still questionable which cacao enzyme might be responsible for the generation of hydrophobic amino acids required for cocoa flavor.
Though some aspects of cocoa flavor production have been elucidated, so far there is still a need in the art to fully understand the processes involved, so that the manufacture of cocoa flavor may eventually be optimized.
SUMMARY
The present invention provides means for further elucidating the processes involved in the formation of cocoa-specific aroma precursors during the fermentation of cacao seeds, to improve the formation of cocoa flavor during processing and manufacturing and eventually providing means assisting in the artificial production of cocoa flavor.
This problem has been solved by providing a nucleotide sequence encoding a novel carboxypeptidase from cacao beans (termed cacao CP-III), which is identified by SEQ. ID. No. 1, or functional derivatives thereof having a degree of homology that is greater than 80%, preferably greater than 90% and more preferably greater than 95%.
It will be appreciated by the skilled person that a gene encoding a specific polypeptide may differ from a given sequence according to the Wobble hypothesis, in that nucleotides are exchanged that do not lead to an alteration in the amino acid sequence. Yet, according to the present invention, also nucleotide sequences shall be embraced which exhibit a nucleotide exchange leading to an alteration of the amino acid sequence such that the functionality of the resulting polypeptide is not essentially disturbed.
This nucleotide sequence may be used to synthesize a corresponding polypeptide by means of recombinant gene technology, in particular, a polypeptide as identified by SEQ. ID. No. 2.
As has been shown in a comparison with other carboxypeptidases from other plants, the present enzyme does not show a substantial homology to any of the carboxypeptidases known so far. Since it is assumed, that cocoa may furthermore contain additional carboxypeptidases that might exhibit a higher homology to the carboxypeptidases known so far, it must be considered as a surprising fact that this very enzyme has been detected.
For producing the polypeptide by recombinant means, the nucleotide of the present invention is included in an expression vector downstream of a suitable promoter and is subsequently incorporated into a suitable cell which may be cultured to yield the polypeptide of interest. Suitable cells for expressing the present polypeptide include bacterial cells, such as e.g. E. coli , or yeast, insect, mammalian or plant cells.
The present DNA sequence may also be incorporated directly into the genome of the corresponding cell by techniques well known in the art, such as e.g. homologous recombination. Proceeding accordingly will provide a higher stability of the system and may include integration of a number of said DNA-sequences into a cell's genome.
The cells thus obtained may in consequence be utilized to produce the polypeptide in batch culture or using continuous procedures, with the resulting polypeptide being isolated according to conventional methods.
The recombinant carboxypeptidase obtained may be used for the manufacture of cocoa flavor. To this end, the enzyme described herein may be utilized in an artificial trial run wherein a mixture of different proteins, such as cacao storage proteins, or protein hydrolysates of other resources, are subjected to enzymatic degradation by means of enzymes known to be involved in proteolytic degradation to eventually assist in the production of flavor precursors. The enzyme may likewise also be utilized in the production of cocoa liquor and in the manufacture of chocolate.
Yet, the present invention also provides plants, in particular cacao plants, comprising a recombinant cell containing one or more additional copies of the carboxypeptidase of the present invention. Such a cacao plant will produce beans, which will exhibit a modified degradation of storage proteins when subjected to the fermentation process, allowing a more rapid degradation or a pattern of hydrolysis that yields a higher level of cocoa flavor precursor since a higher amount of carboxypeptidase will be present.
The carboxypeptidase of the present invention may also be used to produce other transgenic plants, such as soybean and rice, producing seeds with this new protein modifying enzyme.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a scheme illustrating a potential process for the proteolytic formation of cocoa-specific aroma;
FIG. 2 shows the cloning strategy used for the isolation of a cDNA encoding a carboxypeptidase from Theobroma cacao;
FIG. 3 shows a comparison of the hydrophilicity Plot-Kyte-Doolittle for the cacao CP-III sequence with Barley CP-MI, CP-MII and CP-MIII; and
FIGS. 4A , 4 B and 4 C shows a Northern blot analysis of cacao CP-III.
DETAILED DESCRIPTION
As described above, it was suggested that a carboxypeptidase could be involved in the production of cocoa flavor precursors during cacao fermentation. However, it was not known in the art which cacao carboxypeptidase carried out this function considering that five classes of carboxypeptidases (Type I-V) have been identified in different plants by references to differences in substrate specificities, molecular weights and chromatographic profiles. Furthermore, 50 sequences having homologies with serine carboxypeptidases exist in the completed Arabidopsis genome.
The proteoleytic formation of cocoa-specific aroma according to the invention is illustrated in FIG. 1 .
The following examples illustrate the invention further without limiting it thereto. In the examples, the following abbreviations have been used:
PCR: Polymerase Chain Reaction
RACE: Rapid Amplification cDNA Ends
cDNA: complementary deoxyribonucleic acid
mRNA: messenger ribonucleic acid
DEPC: Diethyl pyrocarbonate
3,4-DCI: 3,4-dichloroisocoumarin
EXAMPLES
Materials
Cacao ( Theobroma cacao L.) seeds (male parent unknown) from ripe pods of clone ICS 95 were provided by Nestlé ex-R&D Center Quito (Ecuador). The seeds were taken from the pods immediately after arrival at Nestle Research Center Tours (4-5 days after harvesting). The pulp and the seed coat were eliminated, and the cotyledons were frozen in liquid nitrogen and stored at −80° C. until use.
Preparation of mRNA
Total RNA was prepared using the following method. Two seeds were ground in liquid nitrogen to a fine powder and extraction was directly performed with a lysis buffer containing 25 mM Tris HCl pH8, 25 mM EDTA, 75 mM NaCl, 1% SDS and 1M 3-mercaptoethanol. RNA was extracted with one volume of phenol/chloroform/isoamylalcohol (25/24/1) and centrifuged at 8000 rpm, 10 min at 4° C. The aqueous phase was extracted a second time with one volume of phenol/chloroform/isoamylalcohol (25/24/1). RNA was precipitated with 2M lithium chloride at 4° C. overnight. The RNA pellet obtained after centrifugation was resuspended in DEPC-treated water, and a second precipitation with 3M sodium acetate pH 5.2 was performed in presence of two volumes of ethanol. The RNA pellet was washed with 70% ethanol and resuspended in DEPC-treated water. Total RNA was further purified using the Rneasy Mini kit from Qiagen®.
Cloning of a Carboxypeptidase cDNA
Cloning Strategy
A 1.5 kb 5′-end fragment of a carboxypeptidase from cacao seed was amplified by RT-PCR using a degenerate oligonucleotide. Based on the sequence of this fragment, a primer was designed to amplify a 3′-end fragment. Finally, a full-length cDNA ( cacao CP-III) was amplified using primers specific to both extremities. The cloning strategy used for isolation of a cDNA encoding a carboxypeptidase from Theobroma cacao , clone ICS 95 is shown in FIG. 2 .
Primer Design
A search for carboxypeptidase sequences in the GenBank database led to the identification of several plant sequences. A multiple alignment of these sequences revealed the presence of conserved regions. The conserved sequence MVPMDQP located near the histidine catalytic site has been used to design a degenerate oligonucleotide in the antisense orientation: pCP2r (5′-GGYTGRTCCATNGGNACCAT) (SEQ ID No. 3).
Synthesis of cDNA
Total RNA (see above) was used to synthesize first strand 3′ and 5′ cDNAs with the SMART™ RACE cDNA Amplification Kit (Clontech, USA). Synthesis has been performed exactly as described in the kit instructions using 1 μg of total RNA and the Superscript™ II MMLV reverse transcriptase (Gibco BRL, USA). After synthesis, cDNAs were used directly for PCR or kept at −20° C.
5′ RACE Amplification
Specific cDNA amplification was performed with 2.5 μl of the first strand 5′ cDNA in 50 μl buffer containing: 40 mM Tricine-KOH, pH 8.7, 15 mM KOAc, 3.5 mM Mg(OAc) 2 , 3.75 μg/ml BSA, 0.005% Tween-20, 0.005% Noninet-P40, 0.2 mM dNTP's, 14 pmoles of pCP2r primer, 5 μl of 10× Universal primer Mix (UPM) and 1 μl 50× Advantage 2 polymerase Mix (Clontech, USA). Amplification was performed in a Bio-med thermocycler 60 (B. Braun). A first denaturation step (94° C., 2 min) was followed by 35 cycles of denaturation (94° C., 1 min), primer annealing (55° C., 1.5 min) and extension (72° C., 2 min). The extension time was increased by 3 sec at each cycle. Amplification was ended by a final extension step (72° C., 10 min). The amplified fragment was cloned in pGEM®-T vector and sequenced.
3′ RACE PCR
The sequence information obtained after the sequencing of the 5′ end fragment was used to design a specific oligonucleotide pCP5 (5′-GCTTTTGCTGCCCGAGTCCACC) (SEQ ID No. 4), which was used for 3′-RACE amplification. 3′-RACE PCR was performed with 2.5 μl of SMART single strand 3′ cDNA in 50 μl buffer containing 40 mM Tricine-KOH pH 8.7, 15 mM KOAc, 3.5 mM Mg(OAc) 2 , 3.75 μg/ml BSA, 0.005% Tween-20, 0.005% Nonidet-P40, 0.2 mM dNTP's, 10 pmoles of pCP5 primer, 10 μl of 10× Universal primer Mix (UPM) and 1 μl 50× Advantage 2 polymerase Mix (Clontech, USA). Amplification was performed via touchdown PCR, in a Bio-med thermocycler 60 (B. Braun).
A first denaturation step (94° C., 1 min) was followed by:
5 cycles including denaturation at 94° C. for 30 sec and annealing/extension at 72° C. for 3 min 5 cycles including denaturation at 94° C. for 30 sec and annealing/extension at 70° C. for 30 sec and 72° C. for 3 min 30 cycles including denaturation at 94° C. for 30 sec and annealing/extension at 68° C. for 30 sec and 72° C. for 3 min.
The amplified fragment was cloned in pGEM®-T vector and sequenced.
Full Length cDNA
The sequence information obtained after the sequencing of 5′-and 3′-RACE fragments was used to design two specific oligonucleotides.
pCP8:
A sense primer
(SEQ ID No. 5)
(5′-CAAAGAGAAAAAGAAAAGATGGC)
pCP7r:
A reverse primer
(SEQ ID No. 6)
(5′-CCCCAGAGCTTTACGATACGG).
PCR reaction was performed with 2.5 μl first strand cDNA in 50 pl buffer containing: 40 mM Tricine-KOH pH 8.7, 15 mM KOAc, 3.5 mM Mg(OAc) 2 , 3.75 μg/ml BSA, 0.005% Tween-20, 0.005% Noninet-P40, 0.2 mM dNTP's, 10 pmoles of pCP8 primer, 10 pmoles of pCP7r primer and 1 μl 50× Advantage 2 polymerase Mix (Clontech, USA). Amplification was performed in a Bio-med thermocycler 60 (B. Braun). A first denaturation step (94° C., 1 min) was followed by 35 cycles of denaturation (94° C., 30 sec), primer annealing (63° C., 1 min) and extension (72° C., 2 min). The extension time was increased by 3 sec at each cycle. Amplification was ended by a final extension step (72° C., 10 min). The amplified fragment was cloned in pGEM®-T Easy vector and sequenced.
Sequencing and Analysis of DNA Sequences
cDNA sequencing has been performed by Eurogentech (Belgium) and ESGS (France). Sequence analysis and comparison were performed with Lion's software bioScout, Lasergene software (DNAStar) and Genedoc programme.
The cacao CP-III cDNA sequence is 1768 bp long. A putative initiation start codon was assigned by comparison with other carboxypeptidase sequences. It is located 25 bp from the 5′ end. The open reading frame is broken by a stop codon (TGA) at position 1549, followed by a putative polyadenylation signal (TATAAA) at position 1725.
Cacao CP-III encodes a 508 amino acid type III carboxypeptidase C with a predicted molecular weight of 56 kDa and a pH of 5.04. The catalytic amino acids are present at position Ser 228 , Asp 416 and His 473 . A hydrophilicity analysis was performed using a Lasergene program (DNASTAR) and a window of 9. The results of a comparison of the hydrophiliccity Plot-Kyte-Doolittle for the cacao CP-III sequence with Barley CP-MI, CP-MII AND CP-MIII ( FIG. 3 ) reveals that cacao CP-III encodes a hydrophilic protein with a very hydrophobic N-terminal end, indicating the presence of a signal peptide.
Northern Blot Analysis
Total RNA samples were separated on 1.5% agarose gel containing 6% formaldehyde. RNA was separated on agarose gels, then transferred to a nylon membrane and probed with radiolabelled cacao CP-III cDNA under stringent hybridization conditions. An equal loading of the RNA samples was confirmed by ethidium bromide staining of ribosomal RNA in the gel before transfer to the membrane ( FIG. 4 ). After electrophoresis, RNA was blotted onto nylon membranes (Appligene) and hybridized with 32 P-labeled cacao CP-III probe at 65° C. in 250 mM Na-phosphate buffer pH 7.2, 6.6% SDS, 1 mM EDTA and 1% BSA. Cacao CP-III cDNA fragment was amplified by PCR using pCP8 and pCP7R primers and labelled by the random priming procedure (rediprime™ II, Amersham Pharmacia Biotech). Membranes were washed three times at 65° C. for 30 min in 2×SSC, 0.1% SDS, in 1×SSC, 0.1% SDS and in 0.5×SSC, 0.1% SDS. FIG. 4A illustrates the total RNA (15 μg per lane) from seed and leaf. FIG. 4B illustrates the total mature seed (15 μg per lane) from different T. cacao clones while FIG. 4C illustrates total RNA (15 μg per lane) from seed at different stages of germination.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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The present invention relates to a novel carboxypeptidase gene and the polypeptide encoded thereby. In particular, the present invention relates to the use of the present carboxypeptidase and polypeptide in the manufacture of cocoa flavor and/or chocolate.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 09/612,155, filed Jul. 7, 2000, pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a method and apparatus for compensating or deskewing signal propagation within a printed circuit board (“PCB”). More particularly, the present invention relates to aligning both the rising and falling edges of the system clock, the control signals and the data input and output separately using signal delay elements.
[0004] 2. State of the Art
[0005] As the complexity and data processing speeds of electronic products continue to increase, the properties of the interconnecting circuitry which connects complex and high-speed integrated circuit devices become more pronounced and must be more carefully analyzed and characterized to ensure reliable circuit performance. This increases the cost of fabricating the devices, particularly with regard to the interconnecting circuitry. The data processing speeds obtainable with advanced high-speed integrated circuit devices often dictate the required characteristics of the interconnecting circuitry, and thus can significantly increase the cost of such devices. Currently, integrated circuit devices may operate with a throughput in gigabits per second resulting in pulse durations of less than a nanosecond and rise times in the picosecond range. Under these conditions, even the conductors connecting components within these devices effectively become active components in the circuits, both in terms of affecting propagation delays and impedance matching. Logic circuits are not capable of high-speed circuit operations unless the effects of signal transmission propagation delay are somehow controlled.
[0006] Propagation delays are affected by interconnecting circuitry such as printed circuit boards and assemblies, principally as a result of the dielectric constant (ε r ) of the materials used in the circuitry. In particular, materials having low dielectric constants are desirable as they minimize propagation delays and thereby increase the range of obtainable signal speeds within a circuit.
[0007] Impedance, which is also a function of the dielectric constant (ε r ) of the material used in the circuitry, also affects the obtainable signal speeds within a circuit. Impedance is principally the combination of resistance, capacitance and inductance which create electric and magnetic fields in a circuit. The impedance of a circuit is also called the characteristic impedance, as it depends solely on the characteristics of the materials used and their spacial relationship. Factors such as the dielectric constants of circuit materials and the widths of conductive signal traces primarily affect the characteristic impedance of an electronic circuit.
[0008] Matching the impedances of interconnecting circuitry with that of other electronic devices and connectors is often done in an attempt to ensure signal integrity in a circuit. This is because, particularly at high frequencies, signals may be reflected when impedance mismatches are present in a circuit. Such mismatches distort signals, increase rise times, and otherwise generate errors in data transmission. Consequently, impedance matching is often necessary to provide maximum power transfer between the connected electronic components and systems and to prevent signal reflections from forming along the signal paths.
[0009] As noted above, impedance in a printed circuit is directly related to the separation between signal traces separated by an insulating layer, as well as to the dielectric constant of the material in the insulating layer. The impedance of a given printed circuit board trace where the width is greater than the height of the trace are described by the following equations:
Zo =120 π/[W eff /h )+1.393+0.669*ln[( W eff /j )+1.44]]*(ε eff ) 1/2
ε eff =[(ε r +1)/2]+[(ε r −1)/2]*[1+((12* h )/ w )] −1/2 −[[(ε r −1)*( t/h )]/[4.6*( w/h ) 1/2 ]]; and
W eff =w+[ 1.25* t/π]*[ 1+ln[2* h/t ]]; where:
[0010] Zo=Characteristic impedance;
[0011] ε eff =Effective permittivity of a microstrip trace;
[0012] W eff =Effective width of a microstrip trace;
[0013] ε r =Relative permittivity of material between trace and ground plane;
[0014] h=Trace height over ground;
[0015] w=Trace width; and
[0016] t=Trace thickness.
[0017] Propagation delay, which is also related to the characteristics of the printed circuit board components, is described by the following equation:
Vp= 84.72*10 −12 *(ε eff ) 1/2 ; where
[0018] Vp=Propagation delay; and
[0019] ε eff =Effective permittivity of a microstrip trace.
[0020] One approach to the problem of managing propagation delay is to form expensive six or eight layer printed circuit boards which internally cancel propagation delay. However, there have also been numerous other approaches to controlling propagation delay, some of which include controlling or matching impedance in more simple four layer printed circuit boards.
[0021] U.S. Pat. No. 5,892,384 to Yamada et al. (April 6, 1999) discloses a timing signal generation delay circuit to delay and transmit the clock signal after it detects propagation delay differences, also called skew, from a phase shift between two compared signals. By realigning the phases of the two signals by delaying one, the skew between the signals can be adjusted.
[0022] U.S. Pat. No. 5,926,397 to Yamanouchi (Jul. 20, 1999) discloses a series of individually tailored delay adjusting elements or cells to be inserted in relay spots within a system after considering the resistance, capacitance and inductance effects of the wires on the propagation delay.
[0023] U.S. Pat. No. 5,839,188 to Pommer (Nov. 24, 1998) discloses a specialized adhesive material to control the separation between printed circuit boards in multilayer circuit board applications to control propagation delay.
[0024] U.S. Pat. No. 5,929,199 to Snow et al. (Jul. 27, 1999) discloses a specific process for lowering the dielectric constant of a polymer and using that polymer in a printed circuit to reduce propagation delay.
[0025] U.S. Pat. No. 5,785,789 to Gagnon et al. (Jul. 28, 1998) discloses multilayer printed circuit board structures having partially cured, microsphere-filled resin layers which lower the dielectric constant of the overall structure to reduce propagation delay.
[0026] U.S. Pat. No. 5,945,886 to Millar (Aug. 31, 1999) discloses a method of reducing propagation delay by matching the impedance between two lines by matching the electrical lengths of the traces on a circuit board.
[0027] Although the prior art approaches to the problem of reducing propagation delay will each likely have an effect on propagation delay, each of these approaches also requires additional or specially tailored parts and layers, or processes which significantly add to the cost of fabricating the printed circuit board. Furthermore, the prior art methods do not consider varied characteristics within a circuit board, or differences between circuit boards, for a signal that crosses multiple circuit boards such as in the circuit configuration employed with a Rambus® dynamic random access memory (“RDRAM”).
SUMMARY OF THE INVENTION
[0028] The present invention addresses the problem of signal skew caused by variations in the propagation delay of corresponding signals in an electronic system. In a first embodiment of the invention, a plurality of printed circuit boards (“PCBs”) for use in memory modules are defined upon a common PCB array. The PCBs are laid out such that both a plurality of the sides of the PCBs which will be used for both the first sides of memory modules and a plurality of the sides of other PCBs which will be used for the second sides of memory modules are on the common first side of the array. The corresponding second side of the PCB array also includes PCBs respectively corresponding to the PCBs on the first side. The PCB arrays are then cut into individual PCBs or memory modules. Two PCBs or memory modules are matched and placed in a system such that a first signal which travels from a memory controller and across a side of a first PCB corresponding to the first side of the PCB array also travels across the side of a second PCB corresponding to the second side of the PCB array to terminate at a termination point. Correspondingly, a second signal which originates from a memory controller and travels across the side of the first PCB corresponding to the second side of the PCB array also travels across the side of the second PCB corresponding to the first side of the PCB array before reaching its termination point. In this way, the propagation delay caused by corresponding signals traveling across printed circuit boards made of materials having different dielectric constants respectively is matched or compensated for to substantially eliminate signal skew caused by dielectric constant variations.
[0029] In a second embodiment of the invention, a plurality of printed circuit boards (“PCB”) arrays are defined upon a common PCB panel. The PCB arrays are arranged such that both a plurality of the sides of the arrays which will be used for the first sides of memory modules and a plurality of the sides of other arrays which will be used for the second sides of memory modules are on the common first side of the panel. The corresponding second side of the panel also includes sides of the arrays respectively corresponding to the sides of the arrays on the first side of the panel. The panels are then cut into individual arrays and further into individual PCBs or memory modules. As in the previous embodiment, two PCBs or memory modules are matched and placed in a system such that a first signal which travels across a side of a first PCB corresponding to the first side of the PCB panel also travels across the side of a second PCB corresponding to the second side of the PCB panel. Correspondingly, a second signal which travels across the side of the first PCB corresponding to the second side of the PCB panel also travels across the side of the second PCB corresponding to the first side of the PCB panel.
[0030] In a third embodiment of the invention, rather than using two separate printed circuit boards (PCB) or memory modules, a single printed circuit board is used. The printed circuit board, like those in previous embodiments and common in practice, is formed having a dielectric layer on each side of the PCB. A first circuit trace, or other conductive path, extends for a first distance along a first side of the PCB, through a via, and for a second distance on the second side of the PCB. A second circuit trace, or other conductive path, extends for a distance substantially equal to the second distance along the second side of the PCB, through a via, and, for a distance substantially equal to the first distance, continues on the first side of the PCB.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0031] The nature of the present invention as well as other embodiments of the present invention may be more clearly understood by reference to the following detailed description of the invention, to the appended claims, and to the several drawings herein, wherein:
[0032] [0032]FIG. 1 is an overhead view of both sides of a prior art printed circuit board (PCB) panel layout comprising multiple arrays which, in turn, each comprise multiple PCBs.
[0033] [0033]FIG. 2 is an overhead view of both sides of a prior art PCB array layout comprising multiple PCBs.
[0034] [0034]FIG. 3 is a block diagram of a two-RIMM Rambus-type memory system illustrating the routes the signals travel through the individual RIMMs.
[0035] [0035]FIG. 4 is a cross-sectional view of a four-layer PCB microstrip.
[0036] [0036]FIG. 5 is an overhead view of a PCB array layout according to a first preferred embodiment of the invention.
[0037] [0037]FIG. 6 is an overhead view of a PCB panel layout according to a second preferred embodiment to the invention.
[0038] [0038]FIG. 7 is an overhead view of a PCB according to a third embodiment of the invention.
[0039] [0039]FIG. 8 is a block diagram of a three-RIMM Rambus-type memory system.
[0040] [0040]FIG. 9 is a block diagram of an electronic system including memory fabricated according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Multilayer printed circuit boards (“PCB”) typically comprise layers of resin-impregnated woven glass reinforcement (prepreg) sandwiched between conductive layers of copper foil. The dielectric constant (ε r ) of conventional FR4 epoxy resin and that of common woven glass fiber laminate prepregs is generally on the order of about four to six, respectively. For example, a resin/glass fabric laminate, typically contains about forty percent by weight of glass fabric and about sixty percent by weight of an epoxy resin material. Such laminate prepregs feature a dielectric material having a dielectric constant of approximately 4.6. Plain woven glass fabric has a dielectric constant of about 6.1. Typical raw resin has a dielectric constant of about 3.8. Air has a dielectric constant of 1.
[0042] Even when using a particular, controlled process for forming a printed circuit board of a particular dielectric material, the dielectric constant of the dielectric material layer disposed between the copper traces and the ground or power layer may typically vary from between 3.8 to 4.8. In some cases, the dielectric constant may even vary as low as 3.0 or as high as 6.0. If a more precise range is desired or required for a particular application, the cost of fabrication and classification increases. As would be expected, the cost significantly increases if an exact match in the dielectric constant of the material between the copper traces and the ground or a power layer is required for each side of the PCB.
[0043] Multilayer PCBs are typically formed by adhering large sheets of material to surfaces of other large sheets of material to form large multilayer panels. As shown in FIG. 1, these large multilayer panels 10, by design, are then cut into smaller arrays 12. The panel 10, shown in FIG. 1, is a 24″×20 panel, which may be cut to form six smaller arrays 12 . Depending upon the application in which the PCB will be used, varying sizes of panels and sizes of arrays are available and well known in the art. FIG. 2 illustrates a layout on an array 12 for forming the array 12 into smaller PCBs such as PCB 1 14 and PCB 2 16 . The outermost copper layers on the PCB can be etched in a circuit pattern corresponding to the intended use of the PCB using conventional methods known in the art such as plasma etching and wet etching at the panel level, the array level, or even the PCB level. For efficiency and cost, it is most preferred to etch the traces into the material before they are cut into individual arrays. The PCBs then conventionally have a Rambus memory die attached to them to form RIMM modules for use in two- or three-RIMM module groupings within a Rambus-type system.
[0044] [0044]FIG. 3 is a block diagram of a two-RIMM Rambus-type system 20 comprising a memory controller 22 having at least two signal paths, Signal A 24 and Signal B 26 , a termination 28 for each signal path 24 and 26 , and two RIMMs, RIMM 1 30 , and RIMM 2 32 . The signal paths 24 and 26 are illustrated separate from the RIMMs 30 and 32 for clarity of illustration. However, portions of the signal paths 24 and 26 are, in fact, etched onto the RIMMs 30 and 32 on the respective side nearest the signal path illustrated. As discussed previously, each RIMM is a multilayer RIMM having both a side 1 and a side 2, each of the two sides conventionally having a different dielectric constant associated with it. In a typical Rambus-type system 20 , Signal A 24 , after it leaves the memory controller 22 , travels the length of side 1 of RIMM 1 30 and then the length of side 1 of RIMM 2 32 before reaching its termination 28 . Similarly, Signal B 26 , after it leaves the memory controller 22 , travels the length of side 2 of RIMM 1 30 and then the length of side 2 of RIMM 2 32 before reaching its termination 28 .
[0045] [0045]FIG. 4 depicts a cross-sectional drawing (not-to-scale) of a four-layer PCB microstrip 40 having the characteristics shown. Most significantly, as is typical, Side 1 42 of the PCB microstrip 40 has a different dielectric constant than Side 2 44 . As a result, using the propagation delay equations discussed previously and the values shown in FIG. 4, a signal traveling along the trace 46 on Side 1 42 of the PCB microstrip 40 will have a propagation delay of 153.3 ps/in, while a signal traveling along the trace 48 on Side 2 44 of the PCB microstrip 40 will have a propagation delay of 160.0 ps/in. For the two-RIMM Rambus-type system 20 shown in FIG. 3, assuming similar characteristics for both RIMM 1 30 and RIMM 2 32 , the difference between the propagation delays of the two signals after each travels the length of a side of each of the two RIMMs is:
Total Skew = [ ( RIMM 1 / Side 1 Prop . Delay ) * Side 1 length + ( RIMM 2 / Side 1 Prop . Delay ) * Side 1 length ] - [ ( RIMM 2 / Side 2 Prop . Delay ) * Side 2 length + ( RIMM 2 / Side 2 Prop . Delay ) * Side 2 length ] = | [ ( 153.3 ps / in * 5.25 in ) + ( 153.3 ps / in * 5.25 in ) ] - [ ( 160.0 ps / in * 5.25 in ) + ( 160.0 ps / in * 5.25 in ) ] | = 70.35 ps
[0046] As data speeds become faster, the restrictions on how separated, or skewed, a signal can be from its companion signal becomes more and more significant. For example, the Rambus-type system presently has a maximum skew specification rating of 150 ps. For the system of FIG. 4, at a total skew of 70.35 ps for the signals traveling along only the two RIMMs, the system would quickly exceed the skew indicative of the 150 ps rating.
[0047] The present invention overcomes much of the skew problem by taking advantage of the layout of a typical Rambus-type system and the fairly uniform nature of the dielectric constant (ε r ) within a sheet of printed circuit board material. As shown in FIG. 5, according to a first preferred embodiment of the invention, an array 50 is etched and cut in an alternating pattern of traces such that the printed circuit board (PCB) that will be used for Side 1 52 of RIMM 1 and the PCB that will be used for Side 2 54 of RIMM 2 come from the same first side 56 of the array 50 and thus have substantially the same dielectric constant. Furthermore, by default, the PCB that will be used for Side 2 58 of RIMM 1 and the PCB that will be used for Side 1 60 of RIMM 2 come from the same second side 62 of the array 50 and thus also have substantially the same dielectric constant, whether it be the same or different from the dielectric constant of the first side 56 of the array 50 .
[0048] Under this first preferred embodiment of the invention, when the array laid out in this pattern is cut into a plurality of PCBs, each PCB then having a Rambus die attached and being placed into a Rambus-type system 20 configuration such as that shown in FIG. 3, the propagation delay caused along RIMM 1 30 is compensated for along RIMM 2 32 by eliminating the skew. Thus, the total skew after Signal A 24 and Signal B 26 each travel the lengths of the two RIMMs 30 and 32 is:
Total Skew = [ ( RIMM 1 / Side 1 Prop . Delay ) * Side 1 length + ( RIMM 2 / Side 1 Prop . Delay ) * Side 1 length ] - [ ( RIMM 2 / Side 2 Prop . Delay ) * Side 2 length + ( RIMM 2 / Side 2 Prop . Delay ) * Side 2 length ] = | [ ( 153.3 ps / in * 5.25 in ) + ( 160.0 ps / in * 5.25 in ) ] - [ ( 160.0 ps / in * 5.25 in ) + ( 153.3 ps / in * 5.25 in ) ] | = 0 ps
[0049] Because the dielectric constant of the material for Side 1 52 of RIMM 1 30 is substantially the same as the dielectric constant of the material for Side 2 54 of RIMM 2 32 , and the dielectric constant of the material for Side 2 58 of RIMM 1 30 is substantially the same as the dielectric constant of the material for Side 1 60 of RIMM 2 32 , each of Signal A 24 and Signal B 26 (FIG. 3) travel the length of a PCB side over a material exhibiting a first dielectric constant and the length of a PCB side over a material exhibiting a second dielectric constant. In this way, the propagation delays are compensated for by the PCB system to cancel the overall skew. There will, of course, be variances caused by other factors within the system such as neighboring components and paths, and minor variances within the dielectric material of the PCB. However, the substantial effects of the dielectric constant on the propagation delay will, for the most part, be resolved by the present invention.
[0050] In a second preferred embodiment of the invention, as illustrated in FIG. 6, a printed circuit board (PCB) panel 64 is cut such that half of the arrays 66 on a first side 68 of the panel 64 are patterned as PCBs that will each be used as Side 1 of a RIMM, and half of the arrays 66 are patterned as PCBs that will each be used as Side 2 of a RIMM. Similarly, second side 70 of the panel 64 includes arrays 66 patterned as PCB that will each be used as side 2 of a RIMM, opposite the Side 1 patterns on the first side 68 , while the other half of the arrays 66 on the second side 70 lying under the Side 2 patterned arrays on the first side 68 are patterned as Side 1 PCBs. When each of the arrays are cut, individual PCBs, for example, from an array such as array 4 may be matched with the individual PCBs from an array such as array 1. Since a Side 1 of a PCB from array 1 formed on a first side 68 of a panel 64 is matched with Side 1 of a PCB from array 4 formed on a second side 70 of the panel 68 and Side 2 of the PCB from the second side 70 of array 1 is matched with a PCB bearing a Side 2 formed on a first side 68 of array 4, the propagation delays are equalized and skew is cancelled.
[0051] In a third embodiment of the present invention, as shown in FIG. 7, a first circuit trace 72 travels the first half of its length along a first side 74 of a printed circuit board (PCB) 76 and then travels through a first via 78 to a second side (not shown other than by dashed lines to indicate the second side traces) of the PCB 76 for the second half of its length. A second circuit trace 80 travels the first half of its length along the second side (not shown other than by dashed lines to indicate the second side traces) of the PCB 76 and then travels through a second via 82 to the first side 74 of the PCB for the second half of its length. As with the previous embodiments, transmitting signals across the dielectric material in this pattern compensates for the propagation delay, which is heavily affected by the dielectric constant of the dielectric material over which the signals travel. The PCB system compensates for the propagation delay by allowing multiple signals to travel over material with the same dielectric constant without the cost of setting the specifications for the material so narrowly. FIG. 7 shows the circuit traces 72 and 80 laterally spaced from each other to more easily distinguish between the traces. However, to more closely match the lengths of the traces over the same dielectric material, the circuit trace patterns are preferably placed very close together or, because they are traveling on opposite sides of the PCB 76 , most preferably, placed along a mirrored path with minor variances at a midpoint to allow the signals to be isolated from each other as they pass through vias 78 and 82 .
[0052] [0052]FIG. 8 shows a Rambus-type system configuration like that of FIG. 3 using RIMMs fabricated from PCBs patterned and cut as with the array 50 depicted in FIG. 5, but including a third RIMM 84 . In the embodiment shown in FIG. 8, as with the previously described embodiments, the skew between respective Signals A 24 and B 26 caused by the different dielectric constants of the material used for Sides 1 and 2 of RIMM 1 30 is compensated for by a different skew caused by the different dielectric constants of the material used for Sides 1 and 2 of RIMM 2 32 . Because RIMM 2 32 compensates for the propagation delay of RIMM 1 30 by canceling the skew, there is, effectively, no skew present between the respective Signals A 24 and B 26 as they enter RIMM 3 84 . In this embodiment, because there is no fourth RIMM to compensate for any skew caused by the different dielectric materials in Sides 1 and 2 of RIMM 3 84 , there is no particular need to select RIMM 3 84 from a particular array or having particular dielectric constants, so long as the skew caused by Signals A 24 and B 26 traveling along different sides of RIMM 3 84 does not exceed the overall tolerance allowed for the system. Therefore, while the PCBs used for RIMM 1 30 and RIMM 2 32 should be matched by coming from the same panel or same array according to the present invention, RIMM 3 84 may be from the same, or a different panel or array. A PCB patterned according to the embodiment shown in FIG. 7 and described in relation thereto, however, would be advantageous as RIMM 3 84 because it does not require a second, matching RIMM to compensate for the propagation delay caused by the dielectric materials used for the respective sides of the PCB of that RIMM.
[0053] Contrarily, if a fourth RIMM were used in the system shown in FIG. 8, it would most preferably be fabricated from a PCB patterned and cut as with the array 50 depicted in FIG. 5 such that the propagation delay caused by the respective signals traveling along the dielectric constants of the material used for the respective sides of RIMM 4 could compensate for the propagation delay caused by RIMM 3 84 as discussed with the various embodiments of the present invention. As will be clear to one of skill in the art, for any even number of printed circuit boards used in a system, the boards may be matched according to this invention to cancel skew.
[0054] As will further be clear to one of skill in the art, the specific alternating patterns of RIMM sides and array sides shown and discussed in relation to the foregoing Figures are not required to achieve the advantages of the present invention. It is most preferable to match RIMMs which were physically closer in location to each other on a given PCB layout of an array or panel before they were cut to ensure, in most instances, a closer match of dielectric constants within a specific PCB. It is believed, however, that there is sufficient uniformity of the dielectric constant within a given side of a PCB panel or array to match a RIMM or array with one anywhere on the same PCB panel or array. This matching of PCBs used for specific RIMMs, therefore, may be accomplished using any number of patterns of alternating or adjacent PCBs within common arrays or panels.
[0055] [0055]FIG. 9 is a block diagram of an electronic system 90 which includes RDRAM 92 comprising RIMMs 94 including at least two printed circuit boards matched according to the invention. The electronic system 90 includes a processor 96 for performing various computing functions, such as executing specific software to perform specific calculations or tasks. Additionally, the electronic system 90 includes one or more input devices 98 , such as a keyboard or a mouse, coupled to the processor 96 to allow an operator to interface with the electronic system 90 . Typically, the electronic system 90 also includes one or more output devices 100 coupled to the processor 96 , such output devices typically being a printer, a video terminal or a network connection. One or more data storage devices 102 are also typically coupled to the processor 96 to store data or retrieve data from external storage media (not shown). Examples of typical storage devices 102 include hard and floppy disks, tape cassettes, and compact disks. The processor 96 is also typically coupled to a cache memory 104 , which is conventionally static random access memory (“SRAM”), and to the RDRAM 92 . It will be understood, however, that the propagation delay compensated printed circuit boards of the invention may also be incorporated into any one of the input, output, storage, cache and processor devices 96 , 98 , 100 , 102 and 104 .
[0056] One potential added expense with using the method of the present invention is the expense of tracking the individual arrays and RIMMs by the array or panel from which they came. However, if the processes for creating the dielectric sheets for use in the printed circuit boards (PCB) can reliably ensure a dielectric constant within an acceptable range, there would be no further need to determine if the dielectric constant of the material is beyond that range to specifically match it with another dielectric sheet. The present invention allows for differences between the dielectric sheets used for a specific panel without requiring the additional cost of matching the dielectric constants of the sheets. Therefore, even in light of the added expense of tracking the individual arrays and RIMMs by the panel or array from which they came, the present invention will likely reduce total cost and certainly provide greater product reliability and repeatability of performance. The arrays or individual PCBs for use as RIMMs may be marked at the time of fabrication, such as by bar coding or merely by numbers, lasers or other indicia visible to an operator to distinguish them later.
[0057] Although the invention is shown and described primarily with reference to Rambus-type memory systems using RDRAM, the use of the present invention to compensate for skew in other memory or nonmemory systems are also contemplated within the scope of this disclosure. It is believed that adaptation from the disclosure herein to different architectures and applications will be clear to one of skill in the art. The invention helps reduce propagation delay caused by signal travel through different signal paths of a printed circuit board. Therefore, the present invention will be advantageous in any electronic system where compensation for differences in propagation delay along different signal paths is desired.
[0058] Although the present invention has been shown and described with reference to particular preferred embodiments, various additions, deletions and modifications that are obvious to a person skilled in the art to which the invention pertains, even if not shown or specifically described herein, are deemed to lie within the scope of the invention as encompassed by the following claims.
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A method and apparatus for compensating propagation delay in an electronic system relating to corresponding signals becoming skewed by variations in the dielectric materials over which the respective, corresponding signals travel. Compensation for the propagation delay is done by selecting printed circuit boards which each have one side comprised of a dielectric substrate material exhibiting a first dielectric constant and another side comprised of a dielectric substrate material exhibiting a second dielectric constant. By transmitting each of the corresponding signals across a side of a printed circuit board with a first dielectric constant and a side with a second dielectric constant, the signals are each delayed substantially the same by the effects of the dielectric constant, reducing the skew to zero. In specific application, the printed circuit boards are most easily matched by selecting printed circuit boards from a common printed circuit board panel or array.
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The present invention concerns a process for the separation or purification of gaseous mixtures by the use of a solid adsorption agent or adsorbent. It concerns the operation of this process as well as its applications for industrial separations or purifications.
A known process consists in adsorbing the products to be separated in an enclosure containing a solid adsorbent, whereas at the outlet the products least retained by the solid adsorbent are collected, then in removing the residual mixture which has not been adsorbed and finally recovering the adsorbed substance(s) by the use of a desorption agent which can be thereafter easily separated from the components which are to be produced.
Another method for the separation of gaseous mixtures is elution chromatography which consists in feeding discontinuously the mixture to be separated into a vector gas flow forming an elution agent. The separation is obtained on a solid which selectively adsorbs the constituents of the feed. At the outlet the constituents initially contained in the feed are thus alternatively collected, separated from one another by the elution agent.
The two processes are characterized by the fact that their feed is discontinuous and that they use a third agent, i.e. an elution or desorption agent, which is easily separated from the constituents to be obtained.
Another process is cyclic zone adsorption in which the feed to be treated is passed continuously and without addition of an elution agent in a cascade of enclosures which are packed with a solid adsorbent and brought to cyclically variable temperatures. This process is applicable to systems for which the sorption phenomenon is sensitive to temperature, in order that the temperature variation of the first enclosure produces a separation which is then amplified in the subsequent enclosures.
This last process uses the amplification of the separation created through the use of a series of separators. It requires delicate operation since its correct operation depends on the synchronisation of the different separators, which limits its industrial applications.
The drawbacks of the existing processes are of three kinds:
the presence of an elution or desorption agent which dilutes the constituents of interest and which must thus be capable of being easily separated from the said constituents;
discontinuous feeding which encumbers the operation;
or the necessity of carrying out the separation in a cascade of high interdependent separators which involves a complex operation.
The object of the present invention is to supply a process for the separation or purification of gaseous mixtures on a solid adsorbent capable basically of being operated while using a single separation enclosure containing the adsorbent, continuously fed and without the addition of an elution or a desorption agent at any portion of the production cycle.
BRIEF SUMMARY OF THE INVENTION
The process according to the invention comprises in using temperature essentially as a separation vector inside the enclosure in which a solid adsorbent is contained, continuously fed by a load brought to a temperature T c called high temperature. When the adsorbent is saturated by the feed at temperature T c , the temperature of the feed is then changed to bring it to a new constant value of temperature T F . The temperature is allowed by develop freely in the enclosure under thermal on-set brought to the feed and the heat given off by the adsorbent or consumed by the desorption in the adsorbent sites.
The composition of the gas and the quantities adsorbed in the solid then vary in the enclosure due to the coupling which exists between the temperature and the adsorption phenomena. In fact, adsorption is an exothermic phenomenon and the quantities of a constituent which are adsorbed on a solid adsorbent in balanced conditions varies in relation with the temperature at which the balance is realised.
It is possible from the physicochemical data of the system, specific heat of the adsorbent and adsorption feed, to select high and low temperatures to which the feed is successively subjected in order to form in the enclosure containing the adsorbent three distinct zones moving in the direction of the feed flow at three different speeds;
1. the sorption front, the speed of which depends on the composition of the feed and the temperature T F of the feed;
2. a thermal cooling wave located down-stream of the sorption front in a zone where only the least adsorbable or the non-adsorbable constituents are left. The speed of this wave depends on the specific heat of the adsorbent and the specific heat of the least adsorbable gas, as well as the adsorption characteristics. In the case where this wave is located in a zone which only contains non-adsorbable constituents the speed of this wave is proportional to the average ratio:specific heat of the non-adsorbable gases/specific heat of the adsorbent;
3. a desorption front located down-stream from the thermal wave the speed of which depends on the composition of the feed and the initial temperature T c of the enclosure.
The zone located between the sorption front and the desorption front, in which only the non-adsorbable or least adsorbable constituents are left, and in which is located the cooling wave, tend to widen since the progression of the sorption front located down-stream from this zone is more rapid than the sorption zone upstream of this zone. When this zone exits the enclosure, the nonadsorbable constituents or the least adsorbable constituents according to the case, rid of other constituents, may thus be collected.
In addition, the sorption and desorption fronts act as in the discontinuous adsorption-desorption processes herein-above described and create a separation known as frontal analysis. For the desorption front, it is the least adsorbable or the non-adsorbable constituents which act as desorption agent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a concentration and temperature profile of an adsorption bed at time t 1 after a decrease in feed temperature.
FIG. 2 illustrates the variation with time of the effluent temperature and composition with time after a change in feed temperature.
FIG. 3 illustrates a concentration and temperature profile of an adsorption bed at a time t 3 after an increase in the feed temperature.
FIG. 4 illustrates the variation with time of the effluent temperature, effluent composition with changes in feed temperature at constant feed composition.
FIG. 5 illustrates the variation with time of the effluent temperature, effluent composition with changes in feed temperature at a constant feed composition.
FIG. 6 illustrates the variation with time of the effluent temperature, effluent composition with changes in feed temperature at a constant feed composition through two temperature change cycles.
FIG. 7 illustrates an embodiment of the process where a portion of the effluent is recycled with the feed.
FIG. 8 illustrates an embodiment of the process wherein the effluent is passed in series through absorption beds.
FIG. 9 is a graph showing the effluent temperature and composition with time of the process of the example.
FIG. 10 is a diagrammatic representation of a commercial process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
By this process, a part of the non-adsorbable constituent or a part of the least adsorbable constituent is separated from the remainder of the mixture and this fraction or cut may be collected at the exit of the enclosure containing the adsorbent. In addition, a frontal analysis of the adsorbable constituents is realized in an enclosure zone, as well as an elution of the adsorbable constituent by the non-adsorbable or least adsorbable constituent. Through separating the cuts in the zones as they exit the enclosure it is possible to recover fractions or cuts whose compositions are different from that of the feed.
These results are obtained without addition of a vector gas or a desorption agent. Throughout the entire duration of the process, the feed to the enclosure of the feed mixture is continuous. This process permits the obtention of one very pure fraction without the necessity of amplifying the separation by other enclosures operating in an identical manner.
This has no restrictive character and it is also possible in certain cases to dilute the load in the vector gas or amplify the separation between the adsorbable constituents by combining several enclosures.
The important feature of the process is the choice of high and low temperatures. In the absence of a correct choice of these two temperatures the three distinct zones defined herein-above do not form. The low temperature fixes the speed of the sorption front, which in this case is independent of the high temperature and the high temperature fixes the speed of the desorption front which is independent of the low temperature.
The choice of these temperatures may be made by calculating the speeds of the fronts when sufficient data on the adsorbable constituents is available, for example, the adsorption isotherms on the adsorbent used. This choice may also be made independently through separate adsorption or desorption experiments, while causing a thermal wave to propagate downstream from the sorption front or upstream the desorption front.
The existence of these two temperatures is a consequence of the choice of an adsorbent for which the adsorption isotherms of the constituents present in the load have initial gradients which decrease with the temperature.
In the process according to the invention heat is considered as a particular constituent which can be adsorbed or desorbed on a solid adsorbent. Thus for each adsorbable constituent of the mixture to be separated there may be defined, (without possibly for the least adsorbable in the case where the feed contains only adsorbable constituents) a particular temperature which is called here-after the inversion temperature T r .
When the mixture to be separated contains only adsorbable constituents (or non-adsorbable constituents) the inversion temperature T r is defined for each adsorbable constituent as being the temperature for which the product:
total pressure in the separation enclosure [expressed in atmosphere]×initial gradient of the adsorption isotherm [expressed in (atmosphere) -1 ] of the considered constituent
is equal to the quotient:
specific heat of the adsorbent-adsorbate system, (when the adsorbate is only formed from molecules of less adsorbable gas)/specific heat of the less adsorbable gas, (or the quotient: specific heat of the adsorbent/average specific heat of the non-adsorbable gases).
The lowest of the inversion temperatures is thus the highest limit of the range in which the low temperature of the system must be sought.
The highest of these inversion temperatures is thus the lowest limit of the range in which the high temperature of the system must be sought.
It is possible to affect the values of the inversion temperatures by the choice of the adsorbent, the total pressure and a gaseous dilution agent.
Finally the choice of the high and low temperatures depends on the content of the adsorbable constituents in the feed.
Herein-after are illustrated different non-limiting working methods applied to the case where the feed contains an adsorbable gas and a non-adsorbable gas.
The appropriate T c and T F temperatures have been chosen in relation to the adsorbent used and the composition of the feed.
1st Working Method--Description of the Cold Stage Per Se
The adsorbent is maintained in a column fed continuously by the feed brought to the high temperature, said feed containing an adsorbable constituent A and a non-adsorbable component B.
At instant t 0 the temperature of the feed is decreased in order to bring it to the low temperature T F which is then constantly maintained. This creates in the column a cooling thermal wave followed by a slower sorption front S and preceded by a faster desorption front DS. FIG. 1 shows the speed of these fronts at instant t 1 subsequent to t 0 such as they appear on a photograph of the column at instant t 1 .
This step is continued until the material located between the sorption and desorption fronts is displaced and exits from the column. This material contains only the non-adsorbable constituents B of the feed mixture. In FIG. 1 the arrow at the entry of the column shows the introduction of the load of composition X 0 . The unbroken lines represent the sorption front S and desorption front DS.
The broken line represents the evolution of the temperature from T F to T C . FIG. 2 shows in function of time the evolution of the temperature T 1 of feed, of the temperature T 2 of the gas at exit, of the composition X 1 of feed and the composition X 2 of the gas at exit.
Instant t 2 where the column is again completely saturated, but however, at low temperature T F , is noted.
2nd Working Method--Hot Stage Succeeding the Cold Stage
The column containing the adsorbent is fed continuously by the feed at high temperature. At the instant t 0 the operation proceeds as described in method No. 1. At the instant t 2 where the column is again completely saturated at the low temperature T F the temperature of the feed is again raised to bring it to high temperature T C . This results in the desorption of a part of the adsorbable gas previously adsorbed. At the same time the column heats up progressively. FIG. 3 gives an image of the fronts in the column at instant t 3 subsequent to t 2 . This step is pursued until the desorbed molecules are evacuated out of the column providing an enrichment, at the exit, in adsorbable gas. FIG. 4 shows in function of time the evolution of the temperature T1 of the charge, of the temperature T2 of the gas at the exit, of the composition X1 of the feed, and of the composition X2 of the gas at the exit. Instant t 4 where the desorbed molecules arrive at the exit of the column is noted.
3rd Working Method--Optimal Juxtaposition of a Hot Stage and a Cold Stage
The operation proceeds as in method No. 2 except that the load is brought to high temperature at the instant t' 2 before t 2 , chosen in such a manner that the molecules desorbed by the re-heating of the column arrive at the exit at the same time as the sorption front created during the step where the temperature of the load had been brought to T F . More precisely instant t' 2 is taken as equal to 2t 2 -t 4 . FIG. 5 shows in function of time the evolution of the temperature T1 of the feed, of the temperature T2 of the gas at the exit, of the composition X1 of the feed, and of the composition X2 of the gas at the exit. Instant t 5 where the column is again completely saturated by the feed at temperature T c is noted.
4th Working Method--Optimal Cyclic Chaining of the Hot and Cold Stages
The operation proceeds as in method No. 3, while renewing this operation at instant t' 5 chosen in such a manner that the desorption front, which is created when the feed is brought from T c to T F arrives at the exit of the column at the same time as the extremity of the enrichment front created at the preceding step where the temperature of the load was brought from T F to T c .
More precisely, the instant t' 5 is taken as equal to t 5 -t 1 +t 0 . FIG. 6 shows in function of time the evolution of the temperature T1 of the feed and of the temperature T2 of the gas at the exit, of the composition X1 of the feed and the composition X2 of the gas at the exit.
In indefinitely repeating the process a composition of gas is obtained at the exit, which cyclically varies if the temperature of the feed at the entry cyclically varies. The cycles are determined from the cold and hot steps considered separately.
5th Working Method--Recycling
The operation proceeds as in method No. 4 but a constant fraction of the out-put of exit 3 is recycled continuously in the feed X 0 ; this results in the amplification of the separation if the variations of composition and temperature at the entry are synchronised. FIG. 7 gives the flow-sheet of this working method.
6th Working Method--Disposition in a Cascade of Several Separation Enclosures
According to an embodiment of the invention, several enclosures E1, E2, E3, . . . EN are disposed in a cascade, the feed temperatures of said enclosures varying cyclically in such a way that each successively produces an enriched and an impoverished fraction in the adsorbable constituent. FIG. 8 gives a flow-sheet in the case where N=3. The feed is fed in an enclosure, in the present case E2. The enriched fraction S23 of enclosure E2 constitutes the feed of enclosure E3. The impoverished fraction S21 of enclosure 2 constitutes the feed of enclosure E1, B1, B2, B3 are the storage tanks.
Enclosure E3 produces a fraction enriched in adsorbable constituent SA.
Enclosure E1 operates as in method No. 4 and produces a fraction containing the non adsorbable constituent SB in a very pure state. The existence of a circuit of the enriched fraction rising from any enclosure K to enclosure K+1 until enclosure En is observed, which produces the adsorbable constituent, and a circuit of the impoverished fraction descending from any enclosure K to the preceding enclosure K-1 until enclosure E1 which produces the non-adsorbable constituent is also observed.
In order to operate the method according to the invention, it is necessary to choose for a given separation the adsorbate such that the initial gradient of the adsorption isotherms decrease quicker when the temperature increases, and thus allows the use of a low temperature and high temperature situated in a range easily obtained, for example, between 20° C. and 350° C.
In order to operate the method according to the invention the adsorbent is chosen in relation to the mixture to be treated among the mineral adsorbents such as active carbons, silica, alumina, alumino-silicates, metallic oxides or among the organic adsorbents such as polymers or copolymers, these adsorbents should be chosen in view of their adsorption cavity, the constituents of the feed, their selectivity and their sensibility to temperature in such a way that the inversion temperatures relative to each are found in an accessible range.
For each system constituted by the mixture to be separated and an adsorbent, it is possible, due to the criteria defined herein-above, to determine for a total given pressure, a low and a high temperature and the maximum concentration in the mixture of each of the adsorbable constituents, so that within the range of operating conditions as defined the process is applicable.
EXAMPLE
By way of non-limitative example the invention is illustrated by the operation of the process according to operating method No. 4 in the case where the mixture to be treated contains 95% isopentane, 4.5% n-pentane, 0.25% n-butane and 0.25% isobutane. The aim is to separate the branched hydrocarbons. Therefore, the adsorbent used is a molecular sieve of the 5A type, which adsorbs the n-butane and n-pentane but adsorbs neither the isopentane nor the isobutane. The inversion temperatures of the butane and pentane are in this case comprised between 250° C. and 300° C. for a total pressure of 1.2 bars. A low temperature of 64° C. and a high temperature of 340° C. are chosen. At the low temperature of 64° C. the content of n-pentane and n-butane in the feed is within the range where the process applies. The process uses a stainless steel cylindrical column having a diameter of 10 cm and a length of 1 m containing 5 kg of adsorbent in the form of rods having a length of 3 to 5 mm and a diameter of about 1.6 mm. The rate of feed is constant and equal to approximately 1.9 kg/h. The column is previously saturated at a temperature of 340° C. The head pressure in the column is about 1.2 bars. At instant t=0, when the column is uniformly saturated by the feed at 340° C., the feed temperature is suddenly brought to 64° C.
The desorption front created in the enclosure arrives at the exit in instant t 1 =20 minutes. At instant t 2 =1 hr 20 min the n-pentane content is only 0.1%. From instant t 3 =1 hr 25 min to instant t 4 =3 hr a gas is collected at the exit which contains less than 0.04% n-pentane and n-butane and more than 99.7% isopentane and more than 0.2% isobutane. During this period the temperature of the gas at the exit varies between 212° C. and 101° C. At instant t 5 =2 hr 10 min the temperature of the feed is brought again to 340° C. and maintained at this temperature. Between time t 6 =3 hr 0.5 min and t 7 =3 hr 30 min, the sorption front created when the temperature of the feed was at 64° C., and the desorbed molecules when the temperature of the feed was again brought to 340° C. exit together from the column. During this period the n-pentane content raises from 3.0 % to 15.3%. The n-butane content increases to 3.4% at the instant t 8 =3 hr 10 min and settles thereafter at about 0.25%. From instant t 7 to instant t 9 =4 hr 0.5 min the n-pentane of the gas at exit is never lower than 14.4%. the contents given in this description are volumic percentages. FIG. 9 shows in function of time the composition and the temperature of the effluent as measured at the exit of the column.
FIG. 10 gives an example of a flow-sheet of an industrial process according to the invention operating on the principle described in operating method No. 4. It appears from this figure that the operation of the process according to the invention requires no particular or special installation and may be realized from pre-existing structures. In FIG. 10:
PA, PB represents the compressors;
DA, DB the dryers;
CA, CB, C1, C2 . . . CN the condensors;
FA, FB the ovens;
FICA and FICB the flow controllers
A and B are the enclosures containing the adsorbent.
The process according to the invention may be applied to the purification of industrial gases before recycling or to the separation of the constituents of the mixture. The present invention is in no way limited to the operating methods described and represented; it may be adapted to numerous embodiments known to a man skilled in the art, according to the applications envisaged and without departing from the spirit of the invention.
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A process for continuously separating the constituents of a mixture characterized in that it consists in introducing the gaseous mixture in an enclosure containing a selective adsorption agent or adsorbent, and subjecting the said mixture to a cyclical series of hot and cold steps induced by sudden variations of temperature between a temperature T c called the "hot temperature" and a temperature T F called the "cold temperature" in order to create in the cold steps three distinct zones moving in the flow-direction at different speeds:
a zone of low-speed propagation comprising a sorption front in which the concentration of gas having the most adsorbable constituents decreases;
a zone called the "thermal wave" induced at times determined by the sudden cooling of the load mixture;
a desorption zone where the mixture is enriched in the most adsorbable constituents.
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RELATED APPLICATIONS
Priority is claimed of provisional application No. 60/138,539 filed in the U.S. Patent & Trademark Office on Jun. 10, 1999, the complete disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process of making the low sensitivity, high energy density solid oxidizer 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0 5,9 0 3,11 ]-dodecane, also known as “TEX”. The process provides several advantages over known processes, including faster reaction times with excellent yields and product purity.
2. Description of the Related Art
A synthesis route for preparing TEX is disclosed in U.S. Pat. No. 5,498,711, the complete disclosure of which is incorporated herein by reference. According to the '711 patent, TEX is synthesized by reacting 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine and derivatives thereof with a strong acid and a nitrate source at temperatures greater than ambient temperature, such as temperatures in a range of 50° C. to 70° C. The strong acid and nitrate source of preference are sulfuric acid and nitric acid, respectively. The reaction is exothermic and is allowed to continue for two to three hours. The mixture is then poured onto ice, and a solid precipitate is isolated and washed to give a mixture which contains the TEX. The reaction is shown below:
Purification can then be accomplished by heating the reaction product in nitric acid, washing with methanol, and/or washing with a base to neutralize excess acid. The pure product may be obtained by recrystallization according to standard procedures.
The synthesis route reported in the '711 patent produces TEX in yields and purities that constitute improvements over the known art. However, as is evident from the relatively long reaction times of 2 to 3 hours and the use of NO x scavengers, the '711 patent teaches not terminating the reaction until after TEX is precipitated out and NO x by-product gases are generated. The generation of NO x gases, such as NO 2 , is an autocatalyzing reaction that becomes rapid within a relatively brief period of time, with the actual period depending on various factors, such as piperazine derivative concentration and make-up of the acid bath. Rapid generation of NO x causes fume off of reactants and product, which lowers product yield and makes the process less conducive to applications in large-scale TEX production operations.
SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to address a need in the art by providing a method by which 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0 5,9 0 3,11 ]-dodecane (herein referred to as TEX) can be synthesized at a sufficiently high purity and yield to permit its large scale production in an economically feasible manner.
In accordance with the objects of this invention, these and other objects are accomplished by the provision of process in which TEX is prepared by reacting at least one suitable hexa-substituted piperazine derivative (preferably 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine and/or a derivative thereof) in a medium comprising at least one nitrate source and optionally at least one strong acid at temperatures equal to or greater than ambient temperature, with the reaction temperature preferably being in the range of from about 50° C. to about 80° C. During the initial stages of the reaction, which are highly exothermic, the temperature of the medium is maintained in a range of from about 50° C. to about 80° C. using cooling techniques. Subsequently, the initial exotherm ceases or substantially abates, at which point cooling can be terminated while still maintaining the reaction temperature in the range of from about 50° C. to about 80° C. Eventually, NO x generation commences via an exothermic autocatalytic reaction. Although the inventors do not wish to be bound by any theory, it is believed that the autocatalytic reaction is dependent upon there being a predetermined amount of water present in the medium. The reaction is stopped by cooling the medium to a temperature sufficiently low either to prevent onset of the NO x autocatalytic stage or, if the NO x autocatalytic stage has already commenced prior to the final cooling step, to terminate the autocatalytic generation of NO x . Preferably, the autocatalytic generation of NO x is terminated before a sufficient exotherm has been released to permit the medium (while not being cooled) to be raised in temperature by more than 5° C. The reaction product is precipitated in a conventional manner, preferably by cooling at room temperature, and purified to yield TEX.
Advantageously, because the heat source is removed prior to or just after the formation of NO x , the rapid release and fume off of NO 2 is avoided. Furthermore, unlike many conventional processes, a NO x scavenger, such as urea, may be omitted from the reaction to reduce the likelihood of by-product forming reactions. Moreover, unlike conventional processes, in a preferred embodiment the present invention is conducted in a medium which is free or substantially free of a strong acid other than nitric acid. Counter-intuitively, it has been found that the elimination of a strong acid, such as sulfuric acid, increases the TEX formation rate.
The present process can be conducted on a large manufacturing scale in which the exothermic reaction process is controllable, while directly yielding greater amounts of TEX in a high purity sufficient for use in formulating explosive compositions. These advantages are obtainable without requiring the heretofore extensive further purification or recrystallization steps.
Other objects, aspects and advantages of the invention will be apparent to those skilled in the art upon reading the specification and appended claims, which explain the principles of this invention.
DETAILED DESCRIPTION OF THE INVENTION
In the present process, TEX is prepared by addition of a predried mixture of a hexa-substituted piperazine derivative to a heated acid medium comprising at least one nitrate source and, optionally, at least one strong acid.
Hexa-substituted piperazine derivatives suitable for use in the present process are represented by the following general formula (1):
wherein —OR is a good leaving group and R is H, R″, —CR″O, —COR″, —COOR″, —SO 3 R″, —NO, —NO 2 , acetal (including aliphatic (e.g., formal), cycloaliphatic (e.g., cyclohexanal), and branched acetals (e.g., dimethylketal)), and cycloacetals; R′ is a nitrolyzable group such as —CR″O, —COR″, —SO 2 R″, —SO 3 M, —NO 2 , —NO, —COOR″, t-butyl, cyclohexyl, and isopropyl; M is an alkali metal, preferably lithium, sodium, or potassium; R″ is H, C 1 to C 10 alkyl, branched alkyl, cycloalkyl, and aryl (such as phenyl and substituted phenyl) and monocyclic heterocyclic moieties, and wherein each R, R′, or R″ can independently be the same or different. As used herein, phenyl substituents include, but are not limited to, C 1 to C 10 alkyl, branched alkyl, halogen, nitro, amino, substituted amino, alkoxy, acyl, and carbonyl containing moieties such as carboxyl, ester, ketone, etc. Exemplary, suitable monocyclic heterocyclic moieties contain one or more heteroatoms such as nitrogen, sulfur, and/or oxygen (e.g., triazinethiophenefuran). Representative hexa-substituted piperazine derivatives include, for example,1,4-bis(methylsulphonyl)-2,3,5,6-tetrahydroxypiperazine, disodium-2,3,5,6-tetrahydroxypiperazine-1,4-disulphonate, 1,4-diformyl-2,3,5,6-tetraacetoxypiperazine, and, 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine (THDFP). Of the above hexa-substituted piperazine derivatives, THDFP is the preferred starting material. THDFP is illustrated below by the following formula (2):
Typical hexa-substituted piperazine derivatives which may be used to synthesize TEX can be prepared by reacting glyoxal with an amide, sulfonamide, or sulfonate salt in known methods. Other hexa-substituted piperazine derivatives which may be used in the present invention are reported in Currie, A. C., et al., “Base-catalysed Reactions of Glyoxal. Part I. 1,4-Diformyl- and 1,4-Bismethylsulphonyl-Derivatives of 2,3,5,6-tetrahydroxypiperazines,” Journal of the Chemical Society (Sect. C), pp. 491-496 (1967) and Dinwoodie, A. H. et al, “Base-catalysed Reactions of Glyoxal. Part II. 2,3,5,6-Tetrahydroxypiperazine-1,4-disulphonic Acid Derivatives,” Journal of the Chemical Society (Sect. C), pp. 496-497 (1967).
As used herein, diacyltetraoxypiperazine derivatives also include TEX intermediate products, such as tetraoxadiazaisowurtzitane derivatives which may be prepared from diacyltetraoxypiperazine derivatives.
By preference, the present process also includes several features to reduce the amount of water present in the reaction mixture. The presence of water in the reaction mixture can affect the overall reaction by (a) increasing the NO x produced which increases reaction instability, and (b) decreasing the nitrating strength of the acid which, in turn, decreases yield of TEX.
The hexa-substituted piperazine derivative can be can be subject to a pre-drying treatment prior to addition to the acid medium to obtain, by preference, a finely ground composition. Suitable drying conditions include, for example, overnight drying or drying for about 24 hours under vacuum, typically about 10 mm Hg, at about 50° C. to about 60° C. The upper temperature is limited by the decomposition temperature of the reactants, although the upper temperature can be on the order of about 150° C. This predrying process removes residual water from these materials. As stated above, the predrying treatment results in an increased TEX yield.
The reaction vessel is optionally purged with an inert gas, and the reaction is preferably conducted in a range of from about 50° C. to about 80° C., more preferably about 50° C. to about 70° C. If the reaction is conducted at too low a temperature, for example, below about 50° C., then the formation of undesired side products is increased and yield of TEX is decreased. In contrast, too high a reaction temperature, for example, above about 80° C., results in increased reaction instability and likelihood of fume-off, increased NO x production, and lower TEX yield.
The medium to which the hexa-substituted piperazine derivative starting material is added preferably is preheated to a temperature of between about 55-60° C. Suitably the lower temperature of the medium does not fall below about 55° C. Preferably, the medium temperature is regulated to a maximum of approximately 80° C., although more preferably it is approximately 70° C.
Suitable nitronium ion sources include nitric acid and/or ammonium nitrate. Optionally, strong acids may also be used with the nitronium ion source. Representative strong acids include inorganic acids, such as sulfuric acid, oleum, nitric acid, or hydrohalo acids, such as, hydrochloric acid. Organic acids and anhydrides thereof, such as, trifluoroacetic acid (TFA), and trifluoroacetic anhydride (TFAA), are also suitable for use in the present invention. Preferably, the only strong acid present in the acid medium is nitric acid, and more preferably 100% concentration nitric acid. Where a strong acid other than nitric acid is used, the volumetric ratio of nitric acid to the combination of the other strong acids should be at least about 5:1, preferably about 10:1, and more preferably at least about 20:1. The ratio of nitrate source and strong acid (ml) to grams of hexa-substituted piperazine derivative starting material(s) preferably is at most about 8:1, and more preferably is in a range of from about 4:1 to about 5:1.
The present invention is preferably conducted in an acid medium which is free or substantially free (i.e., not more than 10 vol %) of a strong acid (other than nitric acid). Intuitively, it would seem that the rate of reaction could be increased by increasing the strong acid, e.g., sulfuric acid, concentration in the acid medium, since an increase in sulfuric acid concentration generates a corresponding increase in nitronium ion activity. However, the present inventors discovered, to their surprise, that high concentrations of strong acids, such as sulfuric acid, decrease the rate of TEX formation by promoting foaming during exothermic stages of the reaction.
An inert co-solvent may also be added to the acid medium prior to heating. The inert co-solvent acts as a thermal diluent and heat transfer agent by absorbing the heat generated by the exothermic reaction, boiling, and transferring the heat to a reflux condenser. The inert co-solvent further reduces the intensity of the exotherm and the probability of an uncontrollable reaction. Representative inert co-solvents include 1,2-dichloroethane, methylene chloride, and tetramethylene sulfone (sulfolane).
The hexa-substituted piperazine derivative can be added to the acid medium, or vice versa, at once or in a stepwise or continuous manner. The duration of each stage will depend on several factors, including reaction temperature and acid ratios. Although this invention is not thereby limited, the initial exotherm generally lasts for approximately 2-8 minutes, followed by a substantially non-exothermic stage of approximately 2-15 minutes, followed by the autocatalytic NO x stage.
The reaction product is precipitated by cooling, such as in an ice bath, followed by filtering and purifying. Currently preferred purification techniques include heating the reaction product in nitric acid, washing with methanol, and/or washing with a base to neutralize excess acid.
The pure product may be obtained by suitable separation techniques, such as crystallization or recrystallization techniques known to those skilled in the art. Typical crystallization solvents which may be used include acetonitrile, acetone, butyrolacetone, nitric acid, ethyl acetate, pyridine, DMSO, and DMF.
Typically, TEX yields are greater than 20% by weight based on the amount of piperazine starting material, and the purity is typically 98% or greater based on proton NMR analysis.
The TEX as obtained can be utilized in explosive compositions without the need for further purification or recrystallization steps. The use of TEX in explosive compositions is discussed in greater detail in U.S. Pat. No. 5,529,649, the complete disclosure of which is incorporated herein by reference. TEX may be used alone or in combination with conventional or novel solid explosive ingredients as the basis for formulating very high performance insensitive explosive compositions, such as taught in U.S. Pat. No. 5,587,553, the complete disclosure of which is incorporated herein by reference. For example, TEX may be used in combination with at least one binder, metal, and oxidizer, and optionally other explosive compounds to prepare low cost, castable explosives. Typical formulations may contain from about 5% to about 90% TEX, preferably from about 30% to about 90% TEX; from about 10% to about 30% binder; from about 0% to about 50% oxidizer; and from about 0% to about 30% reactive metal.
Representative inert polymeric binders include HTPB (hydroxy-terminated polybutadiene), PBAN (butadiene-acrylonitrile-acrylic acid terpolymer), PPG (polypropylene glycol), PEG (polyethylene glycol), polyesters, polyacrylates, polymethacrylates, CAB (cellulose acetate butyrate), or mixtures thereof. Representative energetic polymeric binders include PGN (polyglycidyl nitrate), poly-NMMO (nitratomethyl-methyloxetane), GAP (polyglycidyl azide), 9DT-NIDA (diethyleneglycol-triethyleneglycol-nitraminodiacetic acid terpolymer), poly-BAMO (poly(bisazidomethyloxetane)), poly-AMMO (poly(azidomethyl-methyloxetane)), poly-NAMMO (poly(nitraminomethyl-methyloxetane)), copoly-BAMO/NMMO, BAMO/AMMO, nitrocellulose, or mixtures thereof. The binder can optionally be halogenated, such as fluorinated ethylene propylene copolymer, chlorotrifluoroethylene and vinylidene fluoride copolymer, polyvinylidene fluoride, polydifluorochloroethylene, fluorinated polyethers, PVC, polytetrafluoroethylene, or mixtures thereof.
Representative oxidizers include AP (ammonium perchlorate), AN (ammonium nitrate), HAN (hydroxylammonium nitrate), AND (ammonium dinitramide), or mixtures thereof.
Representative reactive metals include aluminum, magnesium, boron, titanium, zirconium, or mixtures thereof.
Other explosives that can be used in combination with TEX include RDX (1,3,5-trinitro-1,3,5-triaza-cyclohexane), HMX (1,3,5,7-tetranitro-1,3,5,7-tetraaza-cycloocatane), NTO (3-nitro-1,2,4-triazol-5-one), NQ (nitroguanidine), HNIW (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0 5,9 0 3,11 ]dodecane), TATB (1,3,5-triamino-2,4,6-trinitrobenzene), and DADNE (1,1-diamino-2,2-dinitro ethane).
TEX and a small amount of binder may also be used to prepare high solids (>90% TEX) pressable or extrudable explosives. The pressable or extrudable explosives have a high solids content and contain up to about 98.5% TEX, preferably from 50% to 98.5% TEX, and most preferably from 80% to 98.5% TEX, or a combination of TEX and other explosive. The pressable or extrudable explosives can also contain inert and/or energetic plasticizers. Representative inert plasticizers include DOA (dioctyladipate), IDP (isodecylperlargonate), DOP (dioctylphthalate), DOM (dioctylmaleate), DBP (dibutylphthalate), oleyl nitrile, or mixtures thereof. Representative energetic plasticizers include BDNPF/BDNPA (bis(2,2-dinitropropyl)acetal/bis(2,2-dinitropropyl)formal), TMETN (trimethylolethanetrinitrate), TEGDN (triethyleneglycoldinitrate), DEGDN (diethyleneglycol-dinitrate), NG (nitroglycerine), BTTN (butanetrioltrinitrate), alkyl NENA's (nitratoethylnitramine), or mixtures thereof.
Melt cast explosives may be prepared by combining TEX with an energetic or inert material having a relatively low melt temperature (<120° C.). Representative meltable energetic materials include TNT (2,4,6-trinitrotouene) and TNAZ (1,3,3-trinitroazetidine). Other meltable energetic materials which may be used include AN/NQ eutectic or alkylammonium nitrate salts. Inert meltable materials such as polyethylene and hydrocarbon wax may also be used. The melt cast explosives may also contain a metal, oxidizer and other nitramine.
The following examples are offered to further illustrate the synthesis methods of the present invention. These examples are intended to be exemplary and should not be viewed as a limitation on the claims.
In the following examples, unless otherwise specified nitric acid (90% ACS Grade) and sulfuric acid (98%, ACS plus) from Fischer, nitric acid (100%) from Fluka, and THDFP from Parish Chemical Company were used without purification.
EXAMPLE 1
A mixture of 1000 ml of 90 vol % nitric acid (10 vol % water) and 100 ml oleum (20 wt % SO 3 ) was heated to 50° C. in a 2 liter jacketed reactor equipped with a mechanical stirrer. 228 g of THDFP were added in one lot. The solid dissolved, a colorless gas was evolved and the reaction temperature rose rapidly. Cooling was controlled (in a water bath of about 18° C.) so as to keep the temperature below 80° C. After 3.5 minutes the temperature was 78° C., the initial exotherm ceased and cooling was stopped. After 8 minutes the reaction had cooled to 64° C. but no precipitate had formed. After 8.5 minutes, the temperature rose to 65° C. and brown NOx evolution became apparent. The solution was rapidly dropped into a 12 liter jacketed reactor cooled to 0° C. The NOx evolution was quenched and a precipitate formed. The precipitate was filtered to give a white crystalline solid that was washed with water until the washings were neutral. The solid was dried and weighed. Yield 53.4 g (23.4% to weight of THDFP). Nmr analysis showed the solid to be >99% TEX.
EXAMPLE 2
50 ml of 100% nitric acid was heated to 45° C. in a 200 ml conical flask equipped with a magnetic stirrer on a water bath held at 55° C. 12.5 g of THDFP were added in one lot. The solid dissolved without foaming, a colorless gas was evolved and the temperature dropped to 40° C. Over 5 minutes the reaction temperature rose to 65° C. (while retaining in the water bath, which was maintained at 55° C.) and the acid refluxed. After 20 minutes the reaction temperature rose to 68° C., signifying the on-set of the NO x autocatalytic stage, without any precipitate apparent. The flask was then rapidly cooled to about 0° C. with ice water and a white precipitate formed. The precipitate was filtered and washed with water until the washings were neutral. The solid was dried and weighed. Yield 3.18 g (25.4% to weight of THDFP). Nmr analysis showed the solid to be >99.5 wt % TEX.
EXAMPLE 3
45 ml of 100% nitric acid and 5 ml of oleum (30 wt % SO 3 ) were mixed and heated to 45° C. in a 200 ml conical flask equipped with a magnetic stirrer on a water bath held at 55° C. 12.5 g of THDFP were added in one lot. The solid dissolved with some foaming apparent and the evolution of a colorless gas. Over 4 minutes the reaction temperature rose to 68° C. (while retaining in the water bath, which was maintained at 55° C.). After 10 minutes the reaction temperature dropped 64° C. (while retaining in the water bath, which was maintained at 55° C.). After 15 minutes the temperature rose to 68° C., signifying the on-set of the NO x autocatalytic stage, without any precipitate apparent. The flask was then rapidly cooled to about −5° C. with ice/acetone and a white precipitate formed. The precipitate was filtered and washed with water until the washings were neutral. The solid was dried and weighed. Yield 3.22 g (25.8% to weight of THDFP). Nmr analysis showed the solid to be >99.5 wt % TEX.
EXAMPLE 4-6
A mixture consisting of 1000 ml of 90 vol % nitric acid (10 vol % water) and 100 ml of oleum (30 wt % SO 3 ) was heated to about 50° C. in a 2 liter jacketed reactor equipped with a reflux condenser, a mechanical stirrer and a bottom outlet. 228 grams of THDFP were added in one lot. The temperature was monitored closely. The temperature/time profiles are shown in table 1 below. When the temperature of the reactants reached 55° C. tap water (temperature about 15° C.) was flushed through the reactor jacket to keep the reaction below 80° C. After the temperature of the reactants stopped rising the cooling was ceased and the reaction temperature was observed to continue decreasing for a short time. As soon as the temperature decrease stopped and a temperature rise of 1° C. was observed the reaction solution was drained into a 12 liter jacketed reactor that had been cooled to 0° C. to stop any further reaction. On rapid cooling a precipitate formed that was then filtered, washed and dried and found to be TEX by nmr analysis. This procedure was repeated twice (Table 1, Examples 5 and 6). In example 6, the temperature was allowed to rise to 81° C. Even though the temperature was brought down after the initial exotherm, a fume-off occurred that could not be quenched by cooling and the reactor could not be rapidlt drained into a cold tank due to the gas evolution in the boiling acid.
TABLE 1
Reaction temperature vs time for synthesis of TEX
Temperature (° C.)
Time (seconds)
Example 4
Example 5
Example 6
0
47
45
45
30
—
54
54
60
57
—
58
90
60
61
62
120
63
64
70
150
66
67
77
180
70
70
80
210
72
72
81
240
74
73
80
270
74
73
78
300
74
72
76
360
68
67
75 (fume off)
420
63
62
—
480
62
58
—
540
55
55
—
600
53
53
—
Reaction
Reaction
Reaction
quenched
quenched
quenched
at 600s
at 600s
at 360s
The foregoing detailed description of the preferred embodiments of the invention has been provided for the purpose of explaining the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. The foregoing detailed description is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Modifications and equivalents will be apparent to practitioners skilled in this art and encompassed within the spirit and scope of the appended claims.
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A process for preparing 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0 5,9 0 3,11 ]-dodecane involves reacting at least one hexa-substituted piperazine derivative with at least one nitrate source and optionally at least one strong acid and heating the mixture to a temperature sufficient to induce an exothermic initial stage of the between the hexa-substituted piperazine derivative and the nitrate source. The mixture is maintained at a temperature in a range of at least ambient to not more than about 80° C. during the exothermic initial stage and at least a portion of a subsequent non-exothermic intermediate stage of the reaction by cooling the mixture during at least a portion of the exothermic initial stage of the reaction so that the reaction proceeds in a controlled manner. The mixture is then cooled to a temperature sufficiently low to prevent commencement of an exothermic NO x autocatalytic stage.
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BACKGROUND OF THE INVENTION
The invention relates to a (foil) pack, especially for paper tissues, having a tear-open flap as an opening aid provided on the upper side with an adhesive tape (or adhesive label), and being limited by lateral perforation lines.
Paper tissues are usually offered in cuboidal packs made of very thin plastic foil or film. Such a pack generally contains ten folded paper tissues.
For some time now, the foil packs have been provided with tear-open aids, mainly of the reclosable type. An especially widespread foil pack of this type has a tear-open flap limited by perforation lines in the region of a (large-surfaced) front wall of the pack. This tear-open flap extends in the direction of an (upper, small-surfaced) end wall. An end region of the tongue-shaped tear-open flap is provided with an adhesive tape, which can be pulled off the front wall with an adhesive-free grip end, thus also pulling the tear-open flap. Herewith, an (upper) extraction opening for the tissues is exposed.
Other embodiments of such foil packs are also known, for example one having a reclosable tear-open aid provided with an adhesive tape in the region of an elongated side wall of the pack.
SUMMARY OF THE INVENTION
The invention is concerned with such cuboidal (foil) packs, especially for paper tissues. The object of the invention is to form a pack provided with a reclosable tear-open aid such that two things are guaranteed, namely an economical industrial production and easiest possible handling for the consumer.
In order to attain this object, the pack according to the invention is characterized in that the tear-open flap has an extension which extends in a wall transverse to the wall having the tear-open aid and which is connected to the adhesive tape (adhesive label) such that for opening the pack, first the extension and then the tear-open flap are moved into opening position.
Preferably, the extension of the tear-open flap is a folding flap within the adjacent and adjoining wall of the packs. When the pack is opened, the folding flap, via the adhesive tape, is therefore moved out of the closing or wall plane first. Then, the perforation limiting the tear-open flap is severed. Now, a unit formed by the tear-open flap and the adjoining folding flap can be moved for forming an extraction opening. Thus, an extraction opening is formed extending within the wall with the tear-open flap and within the adjoining transversely oriented wall. In the preferred embodiment of the invention, the tear-open flap is located in a large-surfaced front wall of the cuboidal pack, in a region next to a small-surfaced end wall. The extension adjoining the tear-open flap is an outer folding flap of the end wall or part of the same. Part of the adhesive tape is joined to the folding flap and furthermore to part of the face of the end wall and the adjoining rear wall. Hence, the pack is opened and in reverse order reclosed via the end wall by pulling the adhesive tape from the rear wall and lifting the outer folding flap and finally by operating the tear-open flap.
It is also of advantage to fold the blank for forming the pack such that in the region of the end wall, side flaps extending from the side walls are first folded against the pack contents and then trapezoidal longitudinal flaps are folded so as to partially overlap. The outer trapezoidal longitudinal flap adjoins to the tear-open flap of the front wall and is connected to the adhesive tape. The invention further provides that the side flaps can be severed from the outer longitudinal flap during the opening process by means of a perforation line.
In a particularly advantageous embodiment of the pack, the tear-open flap or its extension extends within the trapezoidal longitudinal flap of the end wall up to the free edge of the longitudinal flap, with a width being slightly smaller than that of the longitudinal flap 25. By means of appropriate, especially by diverging perforation lines (side perforations), a tear-open flap extending from the free edge of the longitudinal flap up to the front wall of the pack with corresponding extraction opening can be formed.
Further details of the invention are described below with reference to the drawings which show:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a perspective view of a preferred embodiment of a reclosable (foil) pack, especially for paper tissue,
FIG. 2 a perspective view of the pack according to FIG. 1 with opened flap
FIG. 3 a section of the foil web with blanks for a pack according to FIGS. 1 and 2,
FIG. 4 a perspective view of another embodiment of the pack with closed flap,
FIG. 5 the pack according to FIG. 4 with opened flap,
FIG. 6 a section of the foil web with blanks for the packs according to FIGS. 4 and 5,
FIG. 7 a perspective view of a third embodiment of the pack with closed flap,
FIG. 8 a front view of the pack according to FIG. 7 with opened flap,
FIG. 9 a section of a foil web with blanks for packs according to FIGS. 7 and 8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The pack according to FIGS. 1 and 2 is of cuboidal shape with a large-surfaced rectangular front wall 10 and a correspondingly formed rear wall 11. Inbetween front and rear wall are elongated side walls 12 and 13, an upper end wall 14 consisting of folding flaps and a correspondingly formed bottom wall 15. The pack formed this way is made of a rectangular blank 16 consisting of thin plastic foil or film of for instance 30μ or more. The pack serves for holding folded paper tissues 17 arranged in a stack. The blank 16 is shown in FIG. 3 as a section of a foil web 18. Surface portions for forming the above-described pack walls and folding flaps are marked by lines. The blank is folded over the side wall 12 around the stack of paper tissues 17 in a U-shaped manner. Side wall flaps 19 and 20 formed at the free edges overlap one another and are joined to one another for forming the (double-layered) side wall 13, especially by thermal sealing.
Blank portions projecting above and below form folding flaps for the end wall 14 and the bottom wall 15. Side flaps 21 and 22 extending from side walls 12 and 13 are first folded into the plane of end wall 14 and bottom wall 15. Herewith, triangular tabs 23, 24 are formed at the inside of longitudinal flaps 25 and 26. Because of the particular folding geometry, said longitudinal flaps 25, 26 are formed trapezoidally. First, the inner longitudinal flap 26 connected to the rear wall 11 is folded, pulling with it the assigned tabs 24. Then, the outer longitudinal flaps 25 are folded with the tabs 23 into the plane of the end wall 14 and bottom wall 15. Large portions of the longitudinal flaps 25, 26 cover one another, as is shown by FIG. 1.
The pack is equipped with a tear-open aid. For this purpose, a tear-open flap 27 (FIG. 2) is formed in the region of the front wall 10. This tear-open flap 27 directly adjoins the end wall 14, that is to say to a front edge 28 (FIG. 1) formed between front wall 10 and end wall 14. The tear-open flap 27 is laterally limited by perforations, namely by flap perforations 29, 30 (FIG. 1) in the present embodiment, these flap perforations 29, 30 extend at the edges of the front wall 10, specifically in the region of upright longitudinal edges 31, 32 of the pack. The length of the flap perforations 29, 30 is limited, so that a tear-open aid 27 of a relatively small height of for example 1 cm or more is formed.
A portion of the tear-open flap 27 extending beyond the front edge 28 is connected to part of the upper end wall 14, namely to the outer longitudinal flap 25. Consequently, this longitudinal flap 25 is moved out of and back into closing position together with the tear-open flap 27.
The tear-open aid also comprises an adhesive tape 33, which is here designed as a rectangular strip portion, but can also be of other geometrical shapes. One side of the adhesive tape is coated with a (durable) adhesive by means of which said adhesive tape is connected to the pack.
The adhesive tape 33 is attached to the pack in a special place or special relative position. At the free end of the adhesive tape 33 there is an adhesive-free grip flap 34 for operating the adhesive tape 33. A leg 35 of the same--with the grip flap 34--is connected to the rear wall 11. A further leg 36 extends in the region of the upper end wall 14, such that a major portion of this leg 36 of the adhesive tape 33 is connected to the longitudinal flap 25.
When the pack is opened, the grip flap 34 is grasped and then the leg 35 pulled off the rear wall 11. During the further process of operating the adhesive tape 33, the longitudinal flap 25 is lifted from the position in the plane of the front upper end 14. Thereafter, the tear-open flap 37 is severed out of the front wall 10 by destroying the perforation lines (flap perforations 29, 30). In a downwardly directed position of the tear-open flap 27 (with longitudinal flap 25 and adhesive tape 33), an extraction opening is exposed in the region of the front wall 10, said extraction opening in this embodiment extending across the full width of the front wall 10 and including a side tab portions of the upper end wall 14. Thus, an easy extraction of the paper tissues without any need of force is made possible.
The pack is reclosed by pivoting the tear-open flap 27 and the longitudinal flap 25 back into initial position and by sticking the adhesive tape 33 (leg 35) to the rear wall 11. The described opening process is made possible because the tabs 23 can be removed from the plane of the end wall 14 together with the longitudinal flap 25 which they are assigned to. For this purpose, perforation lines 38, 39 (FIG. 3) extending from the flap perforations 29, 30 are disposed in the region of a folding edge between the side flaps 21 and 22 on the one hand and the tabs 23 on the other hand. After the end wall 14 is folded, these perforation lines 38, 39 extend in the front edge 28 or parallel to the same. When the pack is opened by lifting the longitudinal flap 25, the perforation lines 38, 39 are severed, so that the tabs 23 are severed from the side flaps 21, 22 and lifted together with the longitudinal flaps 25 (FIG. 2).
The folding flaps forming the upper end wall 14 are expediently partially connected to one another gluing or sealing. In the region of the tabs 24, the longitudinal flap 26 can be connected to said tabs as well as to the side flaps 21 and 22 by sealing. It is also of advantage, if the outer longitudinal flap 25 is connected to one or several of the other folding flaps such that the connection is removed or destroyed when the pack is opened. The shown embodiment has a longitudinal flap 25 which is joined by a spot-shaped connection, namely by a spot-seal 40, to the inner longitudinal flap 26. When the pack is opened, namely when the longitudinal flap 25 is lifted, this spot-seal 40 is torn apart so that the longitudinal flap 25 is released. Additionally, the tabs 23 can be connected to the longitudinal flaps 25 by sealing.
FIGS. 4, 5 and 6 show details of a pack which mainly corresponds to the embodiment shown by FIGS. 1 to 3, the difference being the design of the tear-open aid. In the region of the upper end wall 14, an adjoining flap 42 is formed, being an extension of the tear-open flap 27 and also being limited by a perforation line 41. The middle region of this adjoining flap 42 is covered by the adhesive tape 33 or by the leg 36 assigned to the end wall 14. When the adhesive tape 33 is pulled off, first the adjoining flap 42 is torn out of the connection with the end wall 14 by removing the perforation line 41. Thereafter, the tear-open flap 42 is pulled off in the region of the front wall 10 in the described way.
In the presently discussed embodiment, the adjoining flap 42 limited by a curved perforation line 41 is part of the outer longitudinal flap 25. In order to improve stability, surface portions of this longitudinal flap 25 lying beyond the adjoining flap 42 can be (firmly) joined to the inner longitudinal flap 26 by sealing or the like.
A further development of the afore embodiment is shown by FIGS. 7 to 9. The tear-open aid which in this embodiment is also formed in the front wall 10 has an extension 43 being part of the longitudinal flap 25 of the adjoining upper end wall 14. This extension 43 extends up to a free edge 44 of the trapezoidal longitudinal flap. The width of the extension 43 is significantly smaller than the length of the longitudinal flap 25, so that when the pack is opened, side strips 45 of the longitudinal flap 25 are retained in the plane of the front wall 14 by means of a durable connection (thermal sealing, adhesive bonding) to the folding flaps of the end wall 14 lying underneath, namely to longitudinal flap 26 and side flaps 21, 22.
In the region of the longitudinal flap 25, the extension 43 of the tear-open flap 27 is limited by side perforations 46, 47, which diverge from the free edge 44 up to the front edge 28, where the side perforations 46, 47 merge into the flap perforations 29, 30 for laterally limiting the tear-open flap in the region of the front wall 10.
The shown preferred embodiment has side perforations 46, 47 in the region of the longitudinal flap 25 which form a rectilinear continuation of the flap perforations 29, 30 which are also converging here in direction of the front edge 28. Hence, these flap perforations 28, 29 form together with the side perforations 46, 47 rectilinear and continuous perforations (FIG. 9). Said flap perforations 29, 30 terminate in the region of the front wall 10 at the longitudinal edges 31, 32, so that in this region--at a distance from the front edge 28--there extends the extraction opening across the full width of the front wall 10. In a lateral region adjacent to the front edge 28, on the other hand, there remain, even when the pack is opened, corner tabs 48 which add to the stability of the pack.
The middle region of the longitudinal flap 25 corresponding to the width of the extension 43 is expediently provided on its bottom side with a coating 49 which prevents the longitudinal flap 25 or the extension 43 from being tightly sealed to folding flaps lying underneath. This coating 49 can be a lacquer coating, a printing or the like.
One of the reasons that the extraction opening 37 exposed in all embodiments guarantees easy access to the pack contents, i.e. to the respective foremost paper tissue 17, is that the longitudinal flaps 25, 26 are of a smaller width then the upper end wall 14. Because of this, the inner longitudinal flap is set back from the front edge 28 when the pack is open and thus enlarges the extraction opening 37 in this region.
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Folded paper tissues are generally packed in thin foil or film. The pack is provided with a tear-open aid having a tear-open flap (27) limited by perforation lines and an adhesive tape (33) partially covering the tear-open flap. For reasons of better handling and economical production of the pack, the tear-open flap (27) is connected to form a unit with part of the end wall (14), namely with an outer longitudinal flap (25) of the same or an adjoining flap (42) or extension (43) formed by the end wall, which can be moved with the aid of the adhesive tape into opening and closing position. In connection with the folding of the end wall (14), the design of the tear-open aid creates an advantageous extraction opening (37) by means of the given width of an inner longitudinal flap (26).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an injection device for a steam iron. This device comprises more particularly a nozzle mounted within an opening in a wall which forms a separation between a water reservoir and a vaporization chamber, said chamber being located beneath the reservoir when the iron is in service. The nozzle has an annular lip which delimits a communication orifice between the reservoir and the chamber. Said nozzle also has a skirt which surrounds the flow passage downstream of the lip with respect to the direction of flow. The device further comprises an injection plunger which is provided with a lateral recess, said plunger being axially displaceable within the orifice between a closed position in which the lip surrounds the plunger between a free end of this latter and the lateral recess, and an injection position in which the lip surrounds the plunger between the two axial ends of said lateral recess.
2. Description of the Prior Art
A known device of this type has already been disclosed in French patent No. FR-A-2,449,157. When the injection plunger moves from one end position to the other, it subjects the lip to flexural deformation and prevents scale formation. Since the smooth region is located beneath the axial recess under operating conditions, the plunger can be moved to the injection position simply by exerting downward pressure, which is a convenient procedure.
This simple construction is nevertheless attended by a disadvantage in that a sheath of scale tends to form beneath the lip around the smooth region of the injection plunger. In such a case, even if the user places the plunger in the injection position, the smooth region of the plunger which is surrounded by and joined to the sheath of scale prevents the water from reaching the vaporization chamber. If the plunger remains in the injection position over a long period of time, it may even be locked in this position as a result of scale formation.
Swiss patent No. CH-A-448,004 discloses an injection device having a nozzle comprising a concave conical seat followed by a calibrated cylindrical orifice at the lower end. A valve which is capable of moving along the axis of the nozzle cooperates with the seat and is adapted to carry in addition a pintle which is engaged within the calibrated orifice when the valve is in the closed position. On the contrary, when the valve is moved away from its seat, the pintle is located above the orifice and the water flows in principle at a rate which is determined by calibration of the orifice. When the valve returns to the closed position, the pintle causes a downward displacement of the scale deposit which may have formed within the orifice and prevents this orifice from subsequently becoming completely incrusted with scale if the device is not actuated for a certain length of time.
In order to overcome the difficulty which may be experienced when operating the valve if the scale forms an adhesive film between the pintle and the orifice, provision is made at the end of the pintle for a spherical bulge or head which is located beyond the orifice when the valve is closed. When the user again opens the valve, the pintle-head is intended to sweep the orifice and thus to produce a de-scaling action. This expedient, however, is not very effective. In point of fact, if the scale has the effect of subjecting the pintle to a braking action, it is difficult if not actually impossible to engage the head within the orifice. Furthermore, if the pintle is jammed within the orifice instead of being simply braked, the pintle-head which is located beyond the orifice cannot produce any action. Supposing finally that the pintle-head performs its function and causes the scale to move upwards to the region of the valve-seat, then either the scale will subsequently impair the leak-tightness of the valve in the closed position or else it will fall back into the orifice and will immediately re-incrust this latter.
SUMMARY OF THE INVENTION
The aim of the invention is thus to propose an injection device of the type mentioned at the outset, in which the sheath of scale which is liable to surround the smooth region of the injection plunger is effectively removed.
In accordance with the invention, the water injection device is distinguished by the fact that the skirt is flexible and that the plunger is provided axially and beyond its smooth region with an annular boss which is surrounded by the skirt in the closed position of the plunger.
By virtue of the flexibility of the skirt, scale can never cause complete jamming of the plunger. If the plunger is moved by hand to its closed position when it is surrounded by a deposit of scale within the skirt, the boss tends to cause displacement of the scale with the plunger. If resistance is encountered, this displacement has the effect of deforming the skirt, thus establishing favorable conditions for fragmentation of the layer of scale and detachment of said layer from the skirt. The fragments of scale then fall and will therefore no longer be liable to engage within the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features of the invention will be more apparent to those skilled in the art upon consideration of the following description and accompanying drawings, wherein:
FIG. 1 is a fragmentary view in side elevation showing a laundry iron in accordance with the invention, with an axial cross-section of the water injection device;
FIG. 2 is a view of the injection device in cross-section along the plane II--II of FIG. 1;
FIG. 3 is a view of the injection plunger in cross-section along the plane III--III of FIG. 1;
FIG. 4 is a view which is similar to FIG. 1 but shows the plunger in the injection position;
FIG. 5 is a view in cross-section along the plane V--V of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
In the example which is illustrated in the figures, the laundry iron comprises a casing 1 of plastic material mounted on a heating sole-plate 2. A vaporization chamber 3 is arranged between the top face of the heating sole-plate 2 and a sheet-metal wall 6b. The heating sole-plate 2 is traversed by steam distribution ducts (not shown in the drawings) through which the vaporization chamber 3 communicates with the exterior beneath the sole-plate 2.
The casing 1 contains a water reservoir 4, the bottom sheet-metal wall 6a of which is located above the top wall 6b of the chamber 3. There is formed between the walls 6a and 6b a hollow space 6c, the function of which is to prevent overheating of the water and formation of steam within the reservoir 4. The walls 6a and 6b are substantially horizontal in the service position of the iron in which the sole-plate 2 itself is horizontal. An opening 7 extends through the walls 6a and 6b, the nozzle 8 of a water injection device 9 being mounted within said opening. By means of this injection device, the water contained in the reservoir 4 is selectively fed drop-by-drop into the vaporization chamber 3 under the action of gravity.
The nozzle 8 comprises a tubular body 11 and the annular end portion of said body which is directed towards the reservoir 4 has an annular flange 12 which is applied around the opening 7 and beneath the bottom sheet-metal wall 6a which is adjacent to the reservoir 4. The bottom wall 6a is in turn provided around the opening 7 with a cylindrical collar 13 which is fitted within the body 11. A metallic tube 14 is crimped at the end nearest the chamber 3 on the circular edge of the plate 6b which is adjacent to the chamber 3, namely the edge which surrounds the opening 7. The tube 14 is force-fitted in the body 11 with zero clearance up to an annular wing 16 of the body 11, said wing being directed radially inwards. The body 11 is thus centered by the cylindrical collar 13 and the tube 14 and is positioned axially between said tube 14 and the sheet-metal wall 6a.
The wing 16 is provided with a flexible annular lip 17, the free edge of which defines a circular orifice 18 (as shown in FIG. 2). The lip 17 is displaced towards the reservoir 4 relatively to the sheet-metal wall 6b in order to be protected as far as possible from the heat generated by the heating sole-plate 2. On that face which is directed towards the vaporization chamber 3, the wind 16 carries within the metallic tube 14 a skirt 19 having a cylindrical internal wall, the diameter of which is larger than the diameter of the orifice 18. Over the greater part of its axial length, the skirt 19 is surrounded by a free space 20 which forms a radial separation between the skirt and the tube 14. The free space 20 extends up to a free end 33 provided on the skirt 19 towards the vaporization chamber 3, and thus communicates with chamber 3 around the skirt 19. The free end 33 projects out of the tube 14 towards the vaporization chamber 3. The body 11, the annular flange 12, the wing 16, the lip 17 and the skirt 19 are formed in a single block of silicone resin.
The injection device 9 further comprises a plunger 21 constituted by a rod having a generally cylindrical shape and formed of heat-resistant plastic material. The rod 21 extends along the axis X--X of the nozzle 8 and in particular of the orifice 18, this axis being perpendicular to the plane of the walls 6a and 6b and of the heating sole-plate 2. At the end remote from the sole-plate 2, the injection plunger 21 is attached to a push-rod 22 which is slidably mounted along the axis X--X within a sleeve 23. The push-rod 22 is connected to a thumb-control push-button 24 which projects from the top of the casing 1.
The injection plunger 21 is provided in the vicinity of the push-rod 22 with a lateral recess 26 constituted by a groove which is directed parallel to the axis X--X. The cross-sectional area of the groove 26 considered in a plane perpendicular to the axis X--X decreases in the direction of the heating sole-plate 2. This is apparent from the decreasing depth of the groove 26 in FIGS. 1 and 4. The injection plunger 21 has a smooth cylindrical region 28 between its groove 26 and the free end 27 which is directed towards the sole-plate 2. The diameter of the plunger 21 in the region corresponding to the groove 26 and in the region 28 is larger than the diameter of the orifice 18 prior to assembly of the plunger 21 and is smaller than the internal diameter of the skirt 19.
By means of a spring-loaded restoring device (not illustrated in the drawings), the injection plunger 21 continuously tends to return to a closed position (as shown in FIG. 1) in which the lip 17 surrounds the smooth cylindrical region 28 of the plunger 21. In this position, the plunger 21 shuts-off the orifice 18 and consequently prevents any flow of water to the vaporization chamber 3.
By depressing the push-button 24 (shown in FIG. 4), the user can displace the injection plunger 21 along the axis X--X until the lip 17 surrounds said plunger 21 in the region corresponding to the groove 26. From that moment onwards (as shown in FIGS. 4 and 5), the groove 26 permits a calibrated leak through the orifice 18, from the reservoir 4 to the vaporization chamber 3. Taking into account the non-constant cross-section of the groove 26, the rate of flow towards the vaporization chamber 3 is correspondingly higher as the plunger 21 is displaced towards the sole-plate 2 with greater force, which can be controlled by the user by varying the pressure exerted on the push-button 24.
In a device of this type, the flexible lip 17 is subjected to flexural deformation and consequently descaled as a result of the axial movements of the plunger 21. Moreover, thanks to the annular end 33 projecting towards the vaporization chamber 3, water reaching said end 33 falls down in the vaporization chamber 3 instead of creeping towards the tube 14 and forming scale there. Formation of scale is thus reduced. On the other hand, if despite this, a tubular deposit having a cross-sectional shape as shown in chain-dotted outline at 29 in FIG. 1 forms within the skirt 19 and if no arrangements are made to guard against this deposit 29, the plunger 21 is liable to be braked or even locked against any further displacements. Moreover, the scale deposit may form a water-tight seal between the skirt 19 and the plunger 21, thus preventing any flow even when the plunger 21 is in the injection position. In order to overcome this difficulty, consideration could be given to the possibility of placing the lip 17 in the plane of the plate 6b but this arrangement would carry a disadvantage in that the lip would be more exposed to heating by the sole-plate 2. Similarly, the plunger 21 would move too close to the sole-plate 2 in the injection position.
In accordance with the invention, the skirt 19 has a thickness in the radial direction which endows it with a certain degree of flexibility, taking into account the material (silicone resin) of which it is made. Furthermore, the plunger 21 is provided at the free end 27 which is directed towards the sole-plate 2 with an annular boss 31 which, when seen in cross-section along a plane which passes through the axis X--X, has the shape of an isosceles triangle, the base of which is parallel to the axis X--X. The external diameter of the boss 31 is smaller than the internal diameter of the skirt 19. Preferably, the boss 31 has an external diameter which enables it to pass through the lip 17 simply by elastic deformation of this latter, thus making it possible to remove the plunger 21 from the top of the iron for cleaning purposes.
When the plunger 21 is in the closed position, the annular boss 31 is surrounded by the skirt 19 (as shown in FIG. 1). Moreover, the distance between the boss 31 and the axial extremity 32 of the groove 26 nearest said boss 31 is greater than or equal to (equal in the example illustrated) the distance between the lip 17 and the annular extremity 33 of the skirt 19 at the downstream end nearest the sole-plate 2. Thus, as soon as the groove 26 engages within the lip 17, the boss 31 passes out of the skirt 19 and therefore does not interfere with the flow along this latter.
Supposing, for example, that the large deposit of scale 29 shown in FIG. 1 has formed within the skirt 19 after a long period of injection and that the user moves the injection plunger 21 back to the closed position. The movement of the boss 31 tends to displace the deposit 29 which has the effect of deforming the skirt 19, thus causing cracking and fragmentation of the scale deposit 29 and detaching this latter from the skirt 19. The fragments detached from the skirt 19 fall onto the sole-plate 2, thus permitting the desired movement of the plunger 21.
The fragments of scale are thus moved permanently away from the injection device.
Numerical examples are given below for certain dimensions of the injection device.
Diameter of the injection plunger 21 : 4 mm
External diameter of the annular boss 31 : 5 mm
Internal diameter of the skirt 19 : 7 mm
Axial dimension of the skirt 19 : 10 mm
Thickness of the skirt 19 : 1.5 mm.
As will readily be apparent, the invention is not limited to the example hereinabove described with reference to the accompanying drawings. On the contrary, many alternative arrangements can be made in this example without thereby departing either from the scope or the spirit of the invention.
From this it accordingly follows that the annular boss can be located at a point short of the free extremity of the plunger and may have a profile which is different from that described and illustrated.
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A water injection device for automatic de-scaling of steam irons comprises an axially displaceable injection plunger (21) which controls the communication between a reservoir (4) and a vaporization chamber (3) according to whether the flexible annular lip (17) of a nozzle (8) surrounds the plunger either in a smooth region (28) or in a laterally recessed region (26). A flexible skirt (19) surrounds the flow passage downstream of the lip (17). The injection plunger (21) terminates in an annular de-scaling boss (31) which is surrounded by the skirt (19) when the plunger is in the closed position.
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BACKGROUND OF THE INVENTION
[0001] (a) Field of the Invention
[0002] The present invention discloses an operative control unit being constituted directly by integrally operated multiple operative control devices of different types for driving individually different driving units, wherein the particular integrally combined operative control unit replaces the complicated central controller as well as the software and monitoring device thereby making the system become the characteristically simple and reliable operative control device.
[0003] (b) Description of the Prior Art
[0004] The interactive relationships among the conventional multiple output operative control units of different types are usually correspondingly treated by the central controller which has a more complicated structure.
SUMMARY OF THE INVENTION
[0005] The present invention discloses a mechanism linking the operative control devices of different types to constitute an integrally driven operative control unit for driving the individually different driving units.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a block schematic view of the application system of the present invention having the operative control unit being constituted by the integrally combined multiple operative control devices of different types.
[0007] FIG. 2 is a block schematic view of the application system in FIG. 1 being additionally installed with a driving interface device for indirectly driving the operative control device.
DESCRIPTION OF MAIN COMPONENT SYMBOLS
[0000]
101 : Operative control device
102 : Integrally combined operative control unit
103 Driving interface device
104 : Driving unit operative control interface
105 : Driving units
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The present invention discloses an operative control unit being constituted directly by integrally operated multiple operative control devices of different types for driving the individual different driving units so as to replace the complicated central controller as well as the software and monitoring device by the particular integrally operative control unit.
[0014] The interactive relationships among the conventional multiple output operative control units of different types are usually correspondingly treated by the central controller which has a more complicated structure.
[0015] The present invention is through a mechanism to link the operative control devices of different types so as to constitute an integrally driven operative control unit for driving the individually different driving units in order to improve the disadvantages of over complication of the conventional ones.
[0016] FIG. 1 is a block schematic view of the application system of the present invention having the operative control unit being constituted by the integrally combined multiple operative control devices of different types.
[0017] As shown in FIG. 1 , the integrally combined operative control unit ( 102 ) is mainly constituted by linking the multiple operative control units of different types ( 101 ) through the mechanism, wherein the operative control devices ( 101 ) are operated in the following one or more than one operating embodiments which includes:
[0018] (1) The operative control device ( 101 ) is directly manually operated; or
[0019] (2) The operative control device ( 101 ) is indirectly manually operated via the driving interface device ( 103 ); or
[0020] (3) The operative control device ( 101 ) is operatively controlled by the signal via the driving interface device ( 103 ) to commonly drive the operative control devices of different types ( 101 ), wherein the driving unit operative control interface ( 104 ) of the individually different driving unit ( 105 ) is operatively controlled by the individual operative control device of different types ( 101 ) so as to operatively control the individually different driving unit ( 105 ).
[0021] The aforesaid driving unit operative control interfaces ( 104 ) being operatively controlled by the individually different operative control devices ( 101 ) comprises at least two respective different driving unit operative control devices ( 104 ) according to the difference of individually operatively controlled driving units ( 105 ), wherein the selectable driving unit operative control devices ( 104 ) for use include:
[0022] Fuel throttle control device of the engine unit; or
[0023] Operative control device of hydraulic actuating unit; or
[0024] Operative control device of pneumatic actuating unit; or
[0025] Control device for motor unit operation; or
[0026] Control device for generator unit operation; or
[0027] Control device for power generation or motor unit functional operation on the same electrical machine; or
[0028] Control device of solenoid driving unit; or
[0029] Control device of mechanical stepped or step-less speed change mechanism unit.
[0030] The at least two selected operative control devices of different types ( 101 ) to constitute the integrally combined operative control unit ( 102 ) of the present invention are constituted by at least two directly manually operated operative control devices ( 101 ), or by the operative control devices ( 101 ) being indirectly operatively controlled via driving interface devices ( 103 ), or by the controlled operative control devices ( 101 ) being operatively controlled by the signal via the driving interface device ( 103 ); wherein the operative control device ( 101 ) includes that:
[0031] It is constituted by the stepless or multi-staged variable resistor device; or
[0032] It is constituted by the stepless or multi-staged variable capacitor device; or
[0033] It is constituted by the stepless or multi-staged variable inductor device; or
[0034] It is constituted by the stepless or multi-staged variable induction type electric potential device; or
[0035] It is constituted by the stepless or multi-staged variable magnetic resistor device (Hall component); or
[0036] It is constituted by the stepless or multi-staged variable optical sensing resistor device; or
[0037] It is constituted by the stepless or multi-staged optoelectronic transistor device of variable impedance; or
[0038] It is constituted by stepless or multi-staged opto-electro converter; or
[0039] It is constituted by changeable multi-staged switch; or
[0040] It is constituted by the ropes or linkage driven stepless or multi-staged variable engine-fuel modulating device; or
[0041] It is constituted by the motor driven stepless or multi-staged variable engine-fuel supply modulating device; or
[0042] It is constituted by the piezoelectric effect driven stepless or multi-staged variable engine-fuel supply modulating device; or
[0043] It is constituted by the solenoid driven stepless or multi-staged variable engine-fuel supply modulating device; or
[0044] It is constituted by the stepless or staged variable operative control device being operated for the functions of detecting or sensing the physical translation, sound, light, and electromagnetism, etc.
[0045] The multiple operative control device ( 101 ) of different types of the present invention to constitute the integrally combined operative control unit ( 102 ) are indirectly manually operated via the driving interface device ( 103 ), or operatively controlled by the signal via the driving interface device ( 103 ), such as that FIG. 2 is a block schematic view of the application system in FIG. 1 being additionally installed with a driving interface device for indirectly driving the operative control device, wherein the installed driving interface device ( 103 ) as shown in FIG. 2 is constituted by at least one of the following driving interface devices ( 103 ) including:
[0046] The hydraulically actuated driving interface device ( 103 ); or
[0047] The pneumatically actuated driving interface device ( 103 ); or
[0048] The electromagnetically actuated driving interface device ( 103 ); or
[0049] The motor actuated driving interface device ( 103 ); or
[0050] The engine power actuated driving interface device ( 103 ).
[0051] In practical applications, the aforesaid integrally combined operative control unit constituted by multiple operative control devices of different types is constituted by at least two individual operative control devices ( 101 ) including the manually operated operative control devices ( 101 ), or the operative control devices ( 101 ) being indirectly operatively controlled via driving interface devices ( 103 ), or the controlled operative control devices ( 101 ) being operatively controlled by the signal via the driving interface device ( 103 ), wherein driving methods of the mechanism linkage for integral operation include 1) linear, or 2) rotational, or 3) simultaneously linear and rotational operating methods and corresponding functioning mechanisms.
[0052] The aforesaid integrally combined operative control unit having multiple operative control devices of different types comprises at least two individual operative control devices ( 101 ) being linked by the mechanism to include the directly manually operated operative control devices ( 101 ), or the operative control devices ( 101 ) being indirectly operatively controlled via driving interface devices ( 103 ), or the controlled operative control devices ( 101 ) being operatively controlled by the signal via the driving interface device ( 103 ), and also include the one installed with switching devices;
[0053] The aforesaid integrally combined operative control unit having multiple operative control devices of different types being linked by mechanism for integral operation has at least two individual operative control devices ( 101 ) which are constituted by directly manually operated operative control devices ( 101 ), or by the operative control devices ( 101 ) being indirectly operatively controlled via driving interface devices ( 103 ), or by the controlled operative control devices ( 101 ) being operatively controlled by the signal via the driving interface device ( 103 ); wherein the operative control devices ( 101 ) are operated in the following one or more than one operating embodiments which include:
[0054] (1) The operative control device ( 101 ) is manually operated; or
[0055] (2) The operative control device ( 101 ) is indirectly manually operated via the driving interface device ( 103 ); or
[0056] (3) The operated operative control devices ( 101 ) are mixedly operated in the two operating embodiments of the direct manual operation and the indirect manual operation via the driving interface device ( 103 ).
[0057] In addition, one or more than one operating characteristics of the following can be optionally selected according to the needs of the operative control:
[0058] (1) For the integrally combined operative control unit having multiple operative control devices of different types of the present invention, wherein the starting points of the integrally operated operative control device of different types ( 101 ) can be the same or different; or
[0059] (2) For the integrally combined operative control unit having multiple operative control devices of different types of the present invention, wherein the closing points of the integrally operated operative control device of different types ( 101 ) can be the same or different; or
[0060] (3) For the integrally combined operative control unit having multiple operative control devices of different types of the present invention, wherein the linear changes of the integrally operated operative control device of different types ( 101 ) can be the same or different; or
[0061] (4) For the integrally combined operative control unit having multiple operative control devices of different types of the present invention, wherein the displacement position of the integrally combined driving mechanism at the linear change starting turning point of the integrally operated operative control device of different types ( 101 ) can be the same or different.
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The present invention discloses a simple and reliable operative control unit being constituted by at least two mechanism linked operative control devices of different types aiming to meet the demand for operating driving units of different types; wherein the multiple operative control devices of different types constituting the operative control unit are linked by mechanism to appear a particular relative relationship for replacing the central controller as well as relevant software and monitoring device so as to reduce the cost and promote the reliability.
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FIELD
[0001] The present disclosure relates generally to high tibial osteotomy. More particularly, the present disclosure relates to an implant and related technique for use in high tibial osteotomy.
BACKGROUND
[0002] 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.
[0003] High tibial osteotomy is a surgical procedure used to correct a malalignment in a tibia. Malalignment in a tibia can accelerate wear in the lateral or medial compartments of the knee and lead to degeneration. Malalignment can include a varus deformation or a “bow-legged” knee condition and a valgus deformation or a “knock-knee” condition. In this regard, a varus knee can cause the protective tissues of the knee to wear more on a medial aspect of the knee. Similarly, a valgus knee can cause the protective tissues of the knee to wear more on the lateral aspect of the knee. In either scenario, it is desirable to perform a high tibial osteotomy to correct the malalignment and position the tibia in a more neutral orientation.
[0004] In one procedure, a varus deformation can be corrected by making a single cut in the medial tibia. The tibia is opened and an implant is positioned within the opening. In another procedure, a valgus deformation can be corrected by making a pair of cuts in the medial tibia and removing a wedge of tibial bone. After the wedge of tibial bone is removed, the void is closed.
[0005] When performing a procedure to correct a varus deformation, typically a surgeon would need to select an implant from a set of implants that has an implant angle suitable for the needs of a particular patient. A large inventory of implants are typically necessary to accommodate a wide range of patients. Furthermore, some implants may not match a profile of the patient's tibia in the transverse plane. In this regard, a need exists to provide a more universal implant suitable for use with a wide range of patients and related method for performing high tibial osteotomy.
SUMMARY
[0006] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
[0007] An implant for use in high tibial osteotomy can include a central implant portion, a first side implant portion and a second side implant portion. The first and second side implant portions can be selectively rotatable relative to each other.
[0008] In one configuration, the first and second implant portions can be hingedly coupled relative to each other. The first side implant portion can include a first hinge arm that defines a first passage therein. The second side implant portion can include a second hinge arm that defines a second passage therein. The implant can further include a hinge post received by the first and second passages. The first and second implant portions can be configured to rotate about the hinge post.
[0009] In additional configurations, the central implant portion can include an arcuate body having an outer arcuate portion and an inner arcuate portion. The central implant can comprise a central solid portion and a central porous portion. The central solid portion can be disposed on the outer arcuate portion. The central porous portion can be disposed on the inner arcuate portion. The first side implant portion can include a first outer solid portion and a first inner porous portion. The first hinge arm can be provided exclusively by the first outer solid portion. The second side implant portion can include a second outer solid portion and a second inner porous portion. The second hinge arm can be provided exclusively by the second outer solid portion. In one example, the first and second side implant portions can be rotatably coupled to each other at a living hinge.
[0010] An implant for use in high tibial osteotomy can include a central implant portion, a first side implant portion and a second side implant portion. The central implant portion can have an arcuate body including a central solid portion and a central porous portion. The central solid portion can include a hinge post. The first side implant portion can have a first outer solid portion and a first inner porous portion. The first outer solid portion can include a first hinge arm that is rotatably coupled to the hinge post. The second side implant portion can have a second outer solid portion and a second inner porous portion. The second outer solid portion can include a second hinge arm that is rotatably coupled to the hinge post. The first and second side implant portions can be selectively rotatably coupled relative to each other.
[0011] According to other features, the central implant portion can further comprise a first upper wing connected to a first lower wing by a first central wall. The first upper wing, the first lower wing and the first central wall can define a first recess. The central implant can further include a second upper wing connected to a second lower wing by a second central wall. The second upper wing, the second lower wing and the second central wall can define a second recess.
[0012] According to additional features, the arcuate body of the central implant portion can include a convex central side and a concave central side. The first and second central walls can taper toward the convex central side. The first side implant portion can be at least partially received by the first recess. The second side implant portion can be at least partially received by the second recess. The implant can be formed as one unit by laser sintering.
[0013] A method of performing high tibial osteotomy according to the present disclosure can include providing an implant having a first superior surface and a second inferior surface. The first superior surface and the second inferior surface can define an implant angle therebetween. A correction angle of the tibia can be determined. A first cut can be made in the tibia. An angle of a second cut relative to the first cut can be determined based on a difference between the implant angle and the correction angle. The second cut can be made in the tibia. The tibia can be opened creating an opening for receipt of the implant. The implant can be inserted into the opening.
[0014] According to other features, a relief hole can be drilled into the tibia with a coring drill. A blade can be advanced through a slot in a guide arm. The blade can be advanced through a keyway defined in the coring drill. At least one of autograph and allograph bone matrix can be deposited into the opening prior to inserting the implant into the opening. The coring drill can remain at one position during the making of the first and second cuts.
[0015] Further areas of applicability of the present disclosure will become apparent from the description provided hereinafter. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0016] The present teachings will become more fully understood from the detailed description, the appended claims and the following drawings. The drawings are for illustrative purposes only and are not intended to limit the scope of the present disclosure.
[0017] FIG. 1 is a front perspective view of an implant for use in high tibial osteotomy constructed in accordance to one example of the present disclosure;
[0018] FIG. 2 is a front perspective view of the implant of FIG. 1 and shown with a first and second side implant portions rotated relative to each other about a hinge;
[0019] FIG. 3 is a front perspective view of a central implant portion of the implant shown in FIG. 1 ;
[0020] FIG. 4 is a front perspective view of the first side implant portion of the implant shown in FIG. 1 ;
[0021] FIG. 5 is a rear perspective view of the first side implant portion shown in FIG. 4 ;
[0022] FIG. 6 is a front perspective view of a second side implant portion of the implant shown in FIG. 1 ;
[0023] FIG. 7 is a rear perspective view of the second side implant portion of FIG. 6 ;
[0024] FIG. 8 is a front perspective view of an implant for use in high tibial osteotomy and constructed in accordance to additional features of the present disclosure;
[0025] FIG. 9 is a front perspective view of an implant for use in high tibial osteotomy and constructed in accordance to other features of the present disclosure;
[0026] FIG. 10 is a medial view of a left tibia shown with a guide arm in a first position and a blade making a first cut during a high tibial osteotomy procedure according to the present disclosure;
[0027] FIG. 11 is a cross-sectional view of the tibia taken along lines 11 - 11 of FIG. 10 ;
[0028] FIG. 12 is a medial view of the left tibia of FIG. 10 shown with the guide arm rotated to a second position and the blade making a second cut;
[0029] FIG. 13 is an anterior view of the left tibia of FIG. 10 shown with the implant positioned on a medial side ready for insertion into an opening of the tibia; and
[0030] FIG. 14 is an anterior view of the left tibia of FIG. 12 shown with the implant advanced into the opening of the tibia.
DETAILED DESCRIPTION
[0031] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. Although the following description is related generally to an implant for high tibial osteotomy, the implant and related technique is not so limited. In this regard, while the following discussion will be directed toward correcting a malalignment in a tibia, the same may be applied to correcting a malalignment in other long bones.
[0032] With initial reference to FIGS. 1 and 2 , an implant for high tibial osteotomy constructed in accordance to the present disclosure is shown and generally identified as implant 10 . As will become appreciated by the following discussion, the implant 10 may be used during a high tibial osteotomy procedure to correct a malalignment in a tibia. The implant 10 can generally include a central implant portion 12 , a first side implant portion 14 and a second side implant portion 16 . The implant 10 can further include a hinge 20 that can allow the first side implant portion 14 and the second side implant portion 16 to selectively rotate relative to each other. While the first and second side implant portions 14 and 16 are shown rotated outwardly an exemplary amount in FIG. 2 , it will be appreciated that the first and second side implant portions 14 and 16 may be rotated outwardly any given amount to specifically match a profile of a patient's tibia 22 ( FIG. 13 ) in a transverse plane. In this regard, the implant 10 can be adjustable to accommodate a tibial profile of a specific patient intraoperatively.
[0033] While the central implant portion 12 , the first side implant portion 14 and the second side implant portion 16 are shown separately in FIGS. 3-7 , they may be formed as a single unit such as during a laser sintering process. In this regard, as described herein, each of the central implant portion 12 , the first side implant portion 14 and the second side implant portion 16 include both solid portions and porous portions. The respective solid and porous portions can be integrally formed during laser sintering. Explained further, the respective solid and porous portions need not be specifically coupled together from distinctly formed pieces. Moreover, the central implant portion 12 , the first side implant portion 14 and the second side implant portion 16 can be formed as a hinged unit. In this regard, the central implant portion 12 , the first side implant portion 14 and the second side implant portion 16 are not required to be specifically assembled together. In one example, the implant can be formed of biocompatible metal such as titanium, titanium alloys, cobalt, cobalt alloys, chromium, chromium alloys, tantalum, tantalum alloys, and stainless steel. Other materials are contemplated.
[0034] With additional reference now to FIG. 3 , the central implant portion 12 will be further described. The central implant portion 12 generally includes an arcuate body 24 that generally includes a central solid portion 26 and a central porous portion 28 . The arcuate body 24 can have an upper portion 30 , a lower portion 32 and a connecting portion 34 . The upper portion 30 , the lower portion 32 and the connecting portion 34 of the arcuate body 24 can collectively provide an outer arcuate portion 40 and an inner arcuate portion 42 . The outer arcuate portion 40 and the inner arcuate portion 42 can generally provide a convex central side 46 and a concave central side 48 , respectively.
[0035] The upper portion 30 can include a first upper wing 50 and a second upper wing 52 . The lower portion 32 can include a first lower wing 54 and a second lower wing 56 . As shown in FIG. 3 , the first and second upper wings 50 and 52 form a continuous sweeping geometry. Similarly, the first and second lower wings 54 and 56 form a continuous sweeping geometry.
[0036] The connecting portion 34 can include a first central wall 60 and a second central wall 62 . The first and second central walls 60 and 62 can generally taper toward the convex central side 46 . The first upper wing 50 , the first lower wing 54 and the first central wall 60 can cooperate to form a first recess 66 . The second upper wing 52 , the second lower wing 56 and the second central wall 62 can cooperate to form a second recess 68 . A hinge post 70 can generally extend between the upper portion 30 and the lower portion 32 near the outer arcuate portion 40 . The hinge post 70 can be formed exclusively of solid material by the central solid portion 26 .
[0037] Turning now to FIGS. 4 and 5 , the first side implant portion 14 will be further described. The first side implant portion 14 generally includes a first arcuate body 74 that generally includes a first solid portion 76 and a first porous portion 78 . The first solid portion 76 can include a first outer solid portion 80 and a first hinge portion 82 . The first hinge portion 82 can include a first hinge arm 86 that defines a first passage 88 . The first porous portion 78 can include a first inner porous portion 90 and a first wall 92 .
[0038] Turning now to FIGS. 6 and 7 , the second side implant portion 16 will be further described. The second side implant portion 16 generally includes a second arcuate body 94 that generally includes a second solid portion 96 and a second porous portion 98 . The second solid portion 96 can include a second outer solid portion 100 and a second hinge portion 102 . The second hinge portion 102 can include a pair of second hinge arms 106 that collectively define a second passage 108 . The second porous portion 98 can include a second inner porous portion 110 and a first wall 112 .
[0039] With reference now to FIGS. 1-7 , the geometries of the central implant portion 12 , the first side implant portion 14 and the second side implant portion 16 will be described. In general, the first wall 92 ( FIG. 4 ) of the first side implant portion 14 can be nestingly received by the first recess 66 ( FIG. 3 ) of the central implant portion 12 . The hinge post 70 can be received by the first passage 88 of the first hinge arm 86 . The second wall 112 ( FIG. 7 ) of the second side implant portion 16 can be nestingly received by the second recess 68 ( FIG. 3 ) of the central implant portion 12 . The hinge post 70 can be received by the pair of second passages 108 of the respective second hinge arms 106 . The first hinge arm 86 can be received between the pair of second hinge arms 106 ( FIG. 1 ). It will be appreciated that the configuration of the hinge 20 is merely exemplary. In this regard, while the first side implant portion 14 is shown having one hinge arm 86 and the second side implant portion 16 is shown having two hinge arms 106 , the configuration may be reversed. Alternatively, each of the first and second hinge arms 86 and 106 may be formed of one or more hinge arms. Moreover, while the hinge post 70 has been described as part of the central implant 12 , the hinge post 70 may additionally or alternatively be incorporated on the first or second implant portion 14 or 16 .
[0040] With reference now to FIG. 8 an implant constructed in accordance to additional features of the present disclosure is shown and generally identified at reference 210 . The implant 210 can generally include a central implant portion 212 , a first side implant portion 214 and a second side implant portion 216 . The implant 210 can further include a hinge 220 that allows the first side implant portion 214 and the second side implant portion 216 to selectively rotate relative to each other. The hinge 220 of the implant 210 can include a living hinge. In this regard, the hinge 220 can deform to allow the first and second side implant portions 214 and 216 to rotate relative to each other.
[0041] The first side implant portion 214 generally includes a first arcuate body portion 230 that includes a first solid portion 232 and a first porous portion 234 . The second side implant portion 216 generally includes a second arcuate body portion 240 that includes a second solid portion 242 and a second porous portion 244 . The first solid portion 232 , the second solid portion 242 and the living hinge 212 can be formed of biocompatible metal. In this regard, the living hinge 212 can be a metal living hinge. Again, as with the implant 10 described above, the first and second side implant portions 214 and 216 can rotate about the living hinge 212 to any given position to specifically match a profile of a patient's tibia 22 ( FIG. 13 ) in the transverse plane.
[0042] With reference now to FIG. 9 an implant constructed in accordance to additional features of the present disclosure is shown and generally identified at reference 310 . The implant 310 can generally include a central implant portion 312 , a first side implant portion 314 and a second side implant portion 316 . The implant 310 can further include a hinge 320 that allows the first side implant portion 314 and the second side implant portion 316 to selectively rotate relative to each other. The hinge 320 of the implant 310 can include a living hinge. In this regard, the hinge 320 can deform to allow the first and second side implant portions 314 and 316 to rotate relative to each other.
[0043] The first side implant portion 314 generally includes a first arcuate body portion 330 that includes a first solid portion 332 and a first porous portion 334 . The second side implant portion 316 generally includes a second arcuate body portion 340 that includes a second solid portion 342 and a second porous portion 344 . The first solid portion 332 , the second solid portion 342 and the living hinge 312 can be formed of polymeric material such as ultra high molecular weight polyethylene. In this regard, the living hinge 312 can be a polymeric or plastic living hinge. Again, as with the implant 10 described above, the first and second side implant portions 314 and 316 can rotate about the living hinge 312 to any given position to specifically match a profile of a patient's tibia 22 ( FIG. 13 ) in the transverse plane.
[0044] With additional reference now to FIGS. 10-14 , an exemplary technique for high tibial osteotomy will be described. In general, the femoral-tibial alignment angle is desirable between 7 and 13 degrees. In the example shown, the tibia is a left tibia having a varus deformation. In this regard, the high tibial osteotomy discussed below will be performed to correct a “bow-legged” malformation. It will be appreciated that the implants and techniques described herein can be also applied for a valgus deformation to correct a “knock-kneed” malformation. To correct the varus deformation, the implant 10 can be advanced into an opening created on the medial side of the tibia 22 ( FIGS. 13 and 14 ).
[0045] At the outset, a surgeon can determine a correction angle 400 of the tibia 22 . In the example shown, the correction angle 400 ( FIG. 14 ) of the tibia 22 will be 10 degrees. In this regard, the medial side of the tibia will be raised 10 degrees. Next, an implant angle 402 ( FIG. 13 ) of the implant 10 can be determined. The implant angle 402 can be an angle between a superior surface 412 of the implant 10 and an inferior surface 414 of the implant. In the example provided, the implant angle 402 is 15 degrees. As will become appreciated, a modular implant 10 having an implant angle 402 of 15 degrees can be used in a variety of examples to correct various valgus and varus deformations. In this way, a modular implant 10 can be used for correcting malalignments on tibias for a wide range of patients.
[0046] Next, a cannulated coring drill 418 can be used to create a relief or datum hole 420 in the tibia 22 . The coring drill 418 can have a coring drill collar 422 that defines a keyway 430 . A blade 434 can then be used to make a first cut 440 ( FIG. 13 ) in the tibia 22 . In one example, the blade 434 can be guided through a slot 450 defined in a guide arm 452 pivotally coupled to the coring drill 418 . The datum hole 420 acts as a datum axis, which can constrain the guide arm and blade 434 across all degrees of freedom except rotation on the coronal plane.
[0047] Notably, the depth of cut in the lateral direction is limited by the coring drill collar 422 . Explained further, the blade 434 can be received by the keyway 430 ( FIG. 11 ) and inhibited from advancing further into the tibia 22 by the collar 422 . Other geometries of the keyway 430 are contemplated for inhibiting further lateral advancement of the blade 434 . The keyway 430 on the coring drill collar 422 can also catch debris created while advancing the blade 434 toward the coring drill collar 422 .
[0048] After the first cut 440 has been made, an angle 458 of a second cut 460 (relative to the first cut 440 ) can be determined. The angle of the second cut 460 will be the implant angle 400 (in this example 15 degrees) minus the angle of correction (in this example 10 degrees). The angle of the second cut 460 (relative to the first cut 440 ) in this example is 5 degrees.
[0049] The guide arm 452 can then be rotated about the drill 418 to the angle 458 of the second cut. In one example indicia can be provided on the guide arm and/or the coring drill collar 422 to assist in attaining the angle 458 . The second cut 460 can then be made using the blade 434 . Again, as with the first cut 440 , the blade 434 can be received by the keyway 430 to inhibit further advancing of the blade 434 into the tibia.
[0050] After the second cut 460 has been made, the blade 434 , guide arm 452 and coring drill 418 can be removed from the tibia. The tibia can then be “opened” to receive the implant 10 . The implant 10 can then be advanced into the opening. In some examples, the first and second side implant portions 14 and 16 can be rotated to substantially match an outer profile of the tibia in the transverse plane. As such, the implant 10 can address patient variability in the anterior-posterior direction. Bone filler 470 such as allograft, autograft or xenograft material can be optionally disposed inboard of the implant 10 .
[0051] As can be appreciated, the present teachings provide a single implant 10 , 210 or 310 that can be applicable for all tibial correction angles. In this way, the tibia 22 can be cut in any manner suitable to accommodate the implant 10 while still attaining any correction angle.
[0052] Exemplary embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, systems and/or methods, to provide a thorough understanding of exemplary embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that exemplary embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
[0053] The terminology used herein is for the purpose of describing particular example implementations only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “and/or” includes any and all combinations of one or more of the associated listed items. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore 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. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
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An implant for use in high tibial osteotomy can include a central implant portion, a first side implant portion and a second side implant portion. The first and second side implant portions can be selectively rotatable relative to each other. A method of performing high tibial osteotomy can include providing an implant having a superior surface and an inferior surface. The first superior surface and the second inferior surface can define an implant angle therebetween. A correction angle of the tibia can be determined. A first cut can be made in the tibia. An angle of a second cut relative to the first cut can be determined based on a difference between the implant angle and the correction angle. The second cut can be made in the tibia. The tibia can be opened creating an opening for receipt of the implant. The implant can be inserted into the opening.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims priority to U.S. Provisional Patent Application No. 61/450,420 filed on Mar. 8, 2011, which is incorporated herein by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of display shelving. More particularly, the present invention relates to a shelving system that incorporates low voltage light fixtures attached to one or more shelves.
BACKGROUND
[0003] In the retail environment, it is common for merchandise to be displayed on a series of adjustable shelves. Retail display shelving falls into two basic categories: (1) cases where shelves are supported by pins inserted into holes on each side of the case or (2) wall displays where a number of vertically oriented, slotted standards are attached to a wall and brackets having hooks designed to engage the slots support the shelves.
[0004] It is desirable to present the merchandise displayed on the shelves in a way that is attractive and easily visible to a potential customer. One way to increase the visibility of merchandise is to provide adequate lighting. In many retail environments, the primary source of lighting is provided by ceiling mounted fixtures. Specific products may also be highlighted or accented through the use of spot lights. When non-illuminated shelving is used, the upper shelves cast shadows that result in less than optimal lighting for the lower shelves.
[0005] There have been previous attempts to create shelving systems with integrated lighting, but those solutions present a number of shortcomings that the present invention seeks to address. Many such shelving systems essentially mounted existing light fixtures to the bottoms of already existing shelves. Such a solution presented the problem that each light fixture had a conventional plug that needed to be plugged into an outlet. For a system with fixed shelves, or shelves with a limited range of adjustment, the power cords could be relatively easily hidden. If the shelving has a broader range of adjustment, it is necessary to provide excess power cord, which is more difficult to hide.
[0006] As such, there is a need for a retail shelving system that incorporates lighting into the shelves such that the shelves may be quickly, easily, and safely reconfigured.
SUMMARY OF THE INVENTION
[0007] The present invention relates to an illuminated shelving system with integrated lighting for displaying items. The illuminated shelving system includes at least one shelf that is removably attached to a shelf support that supports the shelf in a horizontal position. The shelf support further includes a power strip to which the plug is removably attached and which provides electrical power to the light bar. At least one light bar is attached to at least one of the shelves and includes a power cable. An electrical plug is attached to the free end of the power cable. Each shelf includes a channel that encloses the power cable.
[0008] It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a front perspective view of one embodiment of an illuminated shelving system in accordance with the invention;
[0010] FIG. 2 is a perspective view of the illumination components of the shelving system of FIG. 1 ;
[0011] FIG. 3 is a perspective view of another embodiment of an illuminated shelving system in accordance with the invention;
[0012] FIG. 4 is a perspective view of a shelf of the shelving system of FIG. 3 ;
[0013] FIG. 5 is a detail perspective view of the shelf of FIG. 4 , showing the underside detail of the shelf; and
[0014] FIG. 6 is a section view of a lamp bracket in accordance with the shelving system of FIG. 3 , taken generally along the line 6 - 6 in FIG. 4 .
DETAILED DESCRIPTION
[0015] FIG. 1 is a perspective view of one embodiment of an illuminated shelving system in accordance with the invention. The shelving system 100 includes shelves 102 attached to a shelf support 103 , light strips 104 , light strip power cords 105 , cord channels 106 , and plugs 108 that connect to a power strip 110 that, in turn, is connected to a power source by a power cord 112 . As shown, the shelves 102 are removably attached to the shelf support 103 and may be adjusted as required by the retailer to provide the proper spacing for displaying products. The light strips 104 are array of light emitting diodes (LED), but other lighting technologies such as halogen, fluorescent, or incandescent lamps may also be used without departing from the present invention. The light strips 104 may provide continuous brightness across the light strip, or may be configured to illuminate only certain portions of the shelf. Such a configuration allows the light strips 104 to provide accent lighting if so desired.
[0016] The light strips 104 are removably attached to the bottom surface of as many of the shelves 102 as is desired. The light strips 104 may be attached to the shelf 102 by adhesive, hook and loop fastener, bracket, or other attachment means. Each light strip 104 may be removably attached to the power strip 110 .
[0017] FIG. 2 is another perspective view of the illuminated shelving system of FIG. 1 . FIG. 2 shows in greater detail how the lighting components themselves are interconnected. A light strip 104 is connected to a power strip 110 by a light strip power cord 105 and a plug 108 . As shown, the shelving system 100 includes a low voltage lighting system incorporating Light Emitting Diode (“LED”) lighting elements, including the power strip 110 , which is a low voltage power strip such that individual plugs are not necessary. Of course, other power strips may be used without departing from the invention. The power cord 105 and plug 108 may be separate components as shown in FIG. 2 , or may be created as a single component.
[0018] As shown, the power strip 110 is a continuous channel that provides much greater flexibility in terms of where the plug 108 is connected to the power strip 110 than a conventional electrical socket. Such flexibility allows the retailer to position the shelves 102 as desired without concern for where the plug 108 nay be connected to the power strip 110 . The plug 108 shown in the present embodiment is a “Twist and Lock” type, but other types may be used without departing from the invention. A cable channel 106 that guides the light strip power cord 105 from the light strip 104 to the power strip 110 is attached to the underside of each shelf 102 by double sided tape 114 . Other fastening means may also be used without departing from the invention.
[0019] FIGS. 3-6 are perspective views of another embodiment of an illuminated shelving system 200 in accordance with the invention. Electrically, the embodiment illustrated in FIGS. 1-2 and the present embodiment are identical. Rather than attaching the light bar 104 directly to the underside of each shelf 102 , however, the embodiment illustrated in FIGS. 3-6 includes a bracket 202 that is attached to the front edge of an existing shelf 201 . The bracket 202 includes mounts 208 for attaching the light strip 204 , which is electrically attached to a power strip 210 . The bracket 202 may be made of extruded plastic that allows some of the light to illuminate price labels attached to the front of the bracket 206 .
[0020] Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein.
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An illuminated shelving system is provided having light bars attached to the shelves. The light bars are electrically connected to a power strip that conducts electricity from a wall outlet to a plurality of light bars.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 102134612 and 103212139, filed in Taiwan, R.O.C. on 2013 Sep. 25 and 2014 Jul. 8, the entire contents of which are hereby incorporated by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The disclosure relates to a micropump, and particularly to a micropump with a separated pump body.
[0004] 2. Related Art
[0005] A conventional micropump structure has a membrane positioned on the top of a pump body, and an actuator mounted on the top of the membrane in integral. Typically, the actuator is a piezoelectric (PZT) plate.
[0006] In the micro electric mechanical engineering field, the micro fluid-detection and control components are widely used in the precision and automation industry. Particularly in the biomedical field, a used component should be discarded if part of it is in direct contact with body fluids, so as to prevent cross infection or detection errors.
[0007] However, the actuator and the membrane of the conventional micropump are integrated, consequently, when the membrane and pump body are discarded, the expensive actuator is also abandoned at the same time. Consequently, the conventional micropump is highly expensive, a problem requiring a solution.
SUMMARY
[0008] In view of this, the present invention provides a micropump with a separated pump body. This invention can efficiently solve the problem of high cost, while avoiding cross-infection.
[0009] This invention provides a micropump including a pump body and an actuator device.
[0010] The pump body includes a chamber, an inlet communicating with the chamber, an outlet communicating with the chamber and a covering membrane on the top of the chamber. The inlet and the outlet both communicate with the chamber on the opposite sides.
[0011] The actuator device abuts against the membrane. The actuator device includes an actuator and a transmitting post. The transmitting post extends a first end connected to the actuator and a second end abutting against the membrane.
[0012] The actuator drives the transmitting post to swing downwardly and upwardly, so as to depress the membrane to compress the volume of the chamber when downwards, and to recover the membrane to resume the volume of the chamber when upwards.
[0013] Since the pump body is separated from the actuator device, the pump body is disposable and can be replaced with a new one after use. Particularly when using in the medical field or when delivering body fluids, the disposable pump body of the micropump of this invention could avoid cross-infection of disease.
[0014] In one embodiment of the present invention, the first end of the transmitting post has a greater cross section area than that of the second end. Consequently, the transmitting post is easy to locate at the correct position on the membrane.
[0015] This invention also provides a pump body including a chamber, an inlet and an outlet both communicating with the chamber on the opposite sides, and a covering membrane on the top of the chamber. The pump body is disposable and can be replaced each time after use, but the expensive actuator device of the micropump can be reused more than once. Consequently, this invention could reduce the cost of each use of the micropump.
[0016] In one embodiment of the present invention, the membrane includes a first region corresponding to a top opening of the chamber, and a second region which encircling or surrounding the first region, wherein the first region having a higher top surface than that of the second region. Consequently, the deformation of the membrane occurs near the second region, which would enhance the resilience of the membrane when the transmitting post depresses the membrane, and the entire first region compresses the volume of the chamber, which would increase the volume change of the chamber and improve the micropump efficiency.
[0017] In one embodiment of the present invention, the transmitting post abuts against the first region of the membrane. The thickness of the first region is increased, and the transmitting post depresses the first region of the invention. This eliminates the problem caused by the traditional micropump in which the traditional actuator covers the membrane with viscose, the actuator impacts the membrane directly, and the membrane breaks down easily, shortening the lifetime of micropump.
[0018] In one embodiment of the present invention, the area of the first region is greater than or equal to 50% of the area of a top opening of the chamber. In another embodiment of the present invention, the area of the first region is greater than or equal to 66.7% of the area of the top opening of the chamber. In the other embodiment of the present invention, the area of the first region is between 66.7˜80% of the area of the top opening of the chamber. When the transmitting post moves downward to depress the membrane with the same force, the less deformation in the first region could cause the more volume change in the chamber. Consequently, this invention could improve the efficiency of the micropump.
[0019] In one embodiment of the present invention, the membrane is made from Polydimethyl siloxane (PDMS) material. The first region has a double thickness of that of the second region, which would result in more significantly different deformation between the first region and the second region.
[0020] In one embodiment of the present invention, the thickness of the second region is greater than 0.2 mm. In another embodiment of the present invention, the thickness of the second region is preferably between 0.3-0.5 mm. If the thickness of the membrane is insufficient, the membrane will not spring back or recover, due to lack of resilience.
[0021] The detailed features and advantages of the disclosure are described below in great detail through the following embodiments; the content of the detailed description is sufficient for those skilled in the art to understand the technical content of the disclosure and to implement the disclosure there accordingly. Based on the content of the specification, the claims, and the drawings, those skilled in the art can easily understand the relevant objectives and advantages of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus not limitative of the disclosure, wherein:
[0023] FIG. 1 is an exploded view of a micropump of a first embodiment of the disclosure;
[0024] FIG. 2 is an exploded view of the pump body of the first embodiment of the disclosure;
[0025] FIG. 3 is a sectional view of the chamber of the first embodiment of the disclosure;
[0026] FIG. 4 is a sectional view of the pump body of the disclosure;
[0027] FIG. 5 is a schematic view of the micropump is recovered from the disclosure;
[0028] FIG. 6 a schematic view of the micropump is compressed of the disclosure;
[0029] FIG. 7 is a schematic view of a micropump of a second embodiment of the disclosure;
[0030] FIG. 8 is an exploded view of a micropump of a second embodiment of the disclosure;
[0031] FIG. 9 is a sectional view of a micropump of a second embodiment of the disclosure;
[0032] FIG. 10 is a flow rate chart of 2a=7.5 mm of the disclosure; and
[0033] FIG. 11 is a flow rate chart of 2a=10 mm of the disclosure.
DETAILED DESCRIPTION
[0034] Please refer to FIG. 1 , which is an exploded view of a micropump of a first embodiment of the disclosure. As shown, the micropump includes a pump body 1 and an actuator device 9 .
[0035] The actuator device 9 abuts against the membrane 13 . The actuator device 9 includes an actuator 91 and a transmitting post 92 . The transmitting post 92 extends a first end 92 - 1 connected to the actuator and a second end 92 - 2 abutting against the membrane 13 . The actuator 91 is the power source of the micropump. The actuator 91 can be choosing from many elements based on different theorem. For example, Piezoelectric, Electrostatic, Thermo pneumatic, Electromagnetic and Shape memory alloy. In the first embodiment of the disclosure, the actuator 91 is a piezoelectric plat. The piezoelectric material has good performance of converting the electricity to the mechanical energy.
[0036] A micropump usually refers to a pump has a very small chamber radius size between (or below), 2.5 mm˜7.5 mm. As a result of the small size, the process to make the pump body is not easy. Therefore, in this embodiment, the first step of the manufacturing process, cutting (for example, etching or laser cutting) out of the appropriate shape on each substrate, and then combining said substrates to from the pump body. The substrate may choose from different material (for example, plastic or stainless steel.).
[0037] Please refer to FIG. 2 , which is an exploded view of the pump body of the first embodiment of the disclosure. The pump body 1 includes a first substrate 14 , a second substrate 15 and a membrane 13 . The first substrate 14 includes a chamber 10 as a through-hole, a first section inlet 11 a and a first section outlet 12 a. The second substrate 15 includes a second section inlet 11 b and a second section outlet 12 b.
[0038] The first substrate 14 and the second substrate 15 are to combine to form the pump body, so that the first section inlet 11 a communicates with the second section inlet 11 b to from an inlet 11 . The inlet 11 communicates with the chamber 10 . Similarly, the first section outlet 12 a communicates with the second section outlet 12 b to from an outlet 12 . The outlet 12 communicates with the chamber 10 . The membrane 13 covered on top of the chamber 10 .
[0039] Please refer to FIG. 3 , which is a sectional view of the chamber of the first embodiment of the disclosure. The first section inlet 11 a have large caliber of the end near by the chamber 10 , and the other end of the first section inlet 11 a have small caliber. Conversely, the first section outlet 12 a have small caliber of the end near by the chamber 10 , and the other end of the first section outlet 12 a have large caliber. This kind of design is “direction dependent flow resistance”, also call “diffuser/nozzle”.
[0040] The actuator 91 drives the transmitting post 92 to swing up and down. When the transmitting post 92 moves downward to press the membrane 13 , the volume of the chamber 10 is compressed, and the internal pressure of the chamber 10 is increased. Therefore, the fluid inside the chamber 10 would be squeezed out to both the inlet 11 and the outlet 12 , respectively. For the directional arrangement of the first section inlet 11 a and first section outlet 12 a (referred to FIG. 3 ), so as the fluid amount leaving the chamber 10 through the inlet 11 would be less than the fluid amount leaving the chamber 10 through the outlet 12 . Consequently, the fluid inside the chamber 10 is output through the outlet 12 .
[0041] Conversely, when the transmitting post 92 moves upward to recover the membrane 13 , the volume of the chamber 10 is recovered, and the internal pressure of the chamber 10 is decreased. Therefore, the fluid is input through the inlet 11 to the chamber 10 .
[0042] Please refer to FIG. 5 , which is a schematic view of the micropump recovered from the disclosure. The membrane 13 includes a first region 131 and a second region 132 around the first region 131 , and a top surface of the first region 131 is higher than a top surface of the second region 132 .
[0043] Please refer to FIG. 6 , which is a schematic view of the micropump compressed from the disclosure. Since the first region 131 is thicker than the second region 132 , the deformation of the first region 131 is smaller than the second region 132 . Since the transmitting post 92 moves downward to press the membrane 13 , the deformation of the membrane 13 focused on the second region 132 . Consequently, the resilience of the membrane 13 has been raised, the volume change of the chamber 10 has been increased, and the efficiency of the micropump has been improved.
[0044] The membrane 13 and the chamber 10 form an enclosed space (as shown in FIG. 5 ), the volume of the enclosed space is B, so we can also say that the volume of the chamber 10 is B. When the transmitting post 92 moves downward to press the membrane 13 , the volume of the chamber is B′ (as shown in FIG. 6 ). The efficiency formula is B-B′=R, where R is one of the ways to represent the efficiency of the micropump.
[0045] Since the deformation of the first region 131 is smaller than the second region 132 , so the R of the present invention is bigger than the R of the conventional micropump. In other words, in the present invention each swing of the actuator generates a greater volume change than the conventional micropump. This means the same number of swings can result in a greater flow rate.
[0046] Please refer to FIG. 7 , which is a schematic view of a micropump of a second embodiment of the disclosure. The transmitting post 92 has a greater surface area at the end connected the actuator 92 - 1 , the transmitting post 92 has a smaller surface area at the end against the membrane 92 - 2 . The power generated from the actuator 92 has a large area, is converted to the membrane 13 , which has a small area. Consequently, the micropump can complete the pumping action using the power generated by the actuator. Meanwhile, the transmitting post 92 can fix the position of the first region 131 correctly and easily.
[0047] Please refer to FIG. 8 , which is an exploded view of a micropump of a second embodiment of the disclosure. The shape of the first substrate 14 is a cylinder. There is a cavity on the top surface of the first substrate 14 ; is the cavity is chamber 10 . The inner wall of chamber 10 is a stair structure. From bottom to top, the inner wall is defined as a bottom-surface 14 c, a second-surface 14 b and a top-surface 14 c. The inlet 11 and the outlet 12 connect to the bottom-surface 14 c, respectively.
[0048] Please refer to FIG. 9 , which is a sectional view of a micropump of a second embodiment of the disclosure. A size of the membrane 13 is larger than the bottom-surface 14 c, but fits within the second-surface 14 b. The membrane 13 is fixed on the top surface of the second-surface 14 b and surrounded by the top-surface 14 c, thus membrane 13 . The membrane 13 includes the first region 131 and the second region 132 around the first region 131 . In the other words, the second region 132 located in the center of the membrane 13 . The membrane 13 could be one piece, but it is to be understood that the invention need not be limited to the disclosed embodiments. The membrane 13 could be combined with two pieces having different thicknesses or different materials.
[0049] The second substrate 15 includes an inlet valve 151 and a outlet valve 152 . The inlet valve 151 can prevent fluid outflow from the inlet 11 . The outlet valve 152 can prevent fluid inflow through the outlet 12 . Keeping the fluid unidirectional improves the performance of the micropump.
[0050] The inlet valve 151 is embedded into a surface of the second substrate 15 which is near the first substrate 14 . The outlet valve 152 is embedded into a surface of the first substrate 14 , which fairs from the chamber 10 .
[0051] The performance of the micropump relates to the first region 131 , the second region 132 and the size of the chamber 10 . The following paragraphs will discuss these elements.
[0052] The area of the first region 131 is greater than or equal to one half, which is 50 % of the area of the top opening of the chamber 10 . To raise the performance of the micropump, the area of the first region 131 must be of sufficient size. Under optimal conditions, the area of the first region 131 is greater than or equal to two third, which is percentage of 66.7%, of the area of the top opening of the chamber 10 . Under optimal conditions, the area of the first region 131 is between two third to four fifth, which is in percentage of 66.7˜80%, of the top surface area of the chamber 10 .
[0053] Please refer to FIG. 4 , which is a sectional view of the pump body of the disclosure. In the embodiment of the present invention, the membrane 13 is a round-shape. Therefore, the following discussion will concern a radius “a” of the chamber 10 and a radius “b” of the first region 131 . First, obtain a measured data as shown in FIG. 10 using the micropump with a chamber diameter (2a) of 7.5 mm. The X-axis of the chart represents the vibration frequency of the PZT plat (as the actuator 91 ), is 0 Hz to 140 Hz. The Y-axis represents the flow-rate of the micropump is 0 to 25 (g/min). The curve with symbol of “▾” represents a diameter (2b) of the first region is 7 mm. The curve “◯” represents a diameter (2b) of the first region is 6 mm. The curve with symbol of “” represents a diameter (2b) of the first region is 5.25 mm. When the radius ratio (b/a) is between 0.6 to 0.8, the performance of the micropump is good enough. However, if the radius ratio (b/a) is greater than 0.8, such as the curve with symbol of “▾”, of which the radius ratio (b/a) is 0.933, the micropump performance is reduced.
[0054] A second measured data as shown in FIG. 11 using the micropump with a chamber diameter (2a) of 10 mm. We can also obtain similar results as shown in FIG. 10 .
[0055] In the embodiment of the present invention, the membrane 13 is made of a PDMS (Polydimethyl siloxane), material. In the other embodiment of the present invention, the membrane 13 can also be made of PI, silica gel, PE, metal film and any other elastic material.
[0056] In the embodiment of the present invention, the thickness of the first region 131 is twice or more than twice the thickness of the second region 132 . If the first region 131 is too thin, the first region 131 would be broken upon being impacted by the transmitting post 92 .
[0057] In the embodiment of the present invention, if the thickness of the second region 132 is too great, the PZT plat would not have enough power to press downward the membrane 13 . If the thickness of the second region 132 is too small, when the PZT plat leaves the membrane 13 , it could not recover by itself and the micropump performance will be reduced. Consequently, the thickness of the second region 132 is greater than 0.2 mm. Under optimal conditions, the thickness of the second region is between 0.3-0.5 mm. If the thickness of the membrane 13 is insufficient, then the resilience of the membrane will also be insufficient.
[0058] While the disclosure has been described by the way of example and in terms of the preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.
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A micropump and a disposable pump body thereof are disclosed. The micropump includes the pump body and an actuator device. The pump body includes a chamber, an inlet communicating with the chamber, an outlet communicating with the chamber and a covering membrane on top of the chamber. The actuator device includes an actuator and a transmitting post. One of the two ends of the transmitting post connects to the actuator. The other end of the transmitting post abuts against the membrane. Since the pump body is separated from the actuator device, the pump body is disposable and can be replaced after use to avoid cross-infection of disease, particularly useful for medical liquid delivery.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Application No. 61/802,504, filed Mar. 16, 2013, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The described apparatuses and methods relate to the field of microchip handling and assembly. More particularly, the described apparatus and methods relate to the handling and assembly of microchips configured with solid edge-to-edge interconnects.
Description of Related Art
Generally, electronic systems are comprised of multiple discrete microchips. These microchips work together, along with other peripheral devices, to accomplish particular tasks. For the system to function, the discrete microchips must be electrically connected, both to each other and to any other components contained within the system. A wide variety of methods presently exists to accomplish this connectivity, including wire-bonding, bump-bonding, flip-chip, through-silicon-via (TSV), and chip-on-board. Each of these methods is specialized to function with an associated interconnect technology. Specialized assembly and packaging tools are used to handle, align, interconnect, and package microchips. These tools must be designed to accommodate the particular packaging and interconnection approach selected. As new interconnect technologies are created, it becomes necessary to develop new specialized methods and tools to effectively connect microchips using the new technology. Accordingly, there exists a need for new assembly methods and apparatuses that are capable of functioning with cutting-edge interconnect technologies.
SUMMARY OF THE INVENTION
The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended either to identify key or critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
With the creation of microchips configured with solid edge-to-edge interconnects, a need has arisen for new, specialized tools and methods to effectively connect discrete microchips together. For example, existing methods are incapable of the precision alignment required to connect multiple edge-based contact points. Further, existing methods are inadequate at reliably forming functional mechanical and electrical connections directly between adjacent microchips.
Accordingly, the described apparatuses and methods relate to the field of microchip assembly and handling, in particular to devices and methods for assembling and handling microchips manufactured with solid edge-to-edge interconnects, such as Quilt Packaging® interconnect technology. Specialized assembly tools are described that are configured to pick up one or more microchips, place the microchips in a specified location aligned to a substrate, package, or another microchip, and facilitate electrical contact through one of a variety of approaches, including solder reflow. This specialized assembly tooling performs heating functions to reflow solder to establish electrical and mechanical interconnections between multiple microchips.
In an embodiment, after two or more microchips have been positioned and interconnected on a package, the assembly tooling can finish either by sealing the package with a cover or sealant or by moving the assembled unit along for further processing.
In an embodiment, a device is capable of performing the precision alignment needed to join solid edge-to-edge interconnect structures and prevent lateral movement and pressure during solder reflow. In another embodiment, vacuum is used to hold multiple microchips in place while additional microchips of the same or varying geometries, sizes, and thicknesses are aligned into an interconnected array or quilt. In an embodiment, microchips can be assembled into such an array either on a stage and then reflowed or alternatively assembled directly on a package or substrate and reflowed. In an embodiment, microchips can be assembled either orthogonally or at other angles to one another. After assembly, the array of interconnected microchips can be moved into a package, onto a substrate or board, encapsulated, or otherwise protected by the application of a protective material, such as an epoxy or polymer.
To the accomplishment of the foregoing and related ends, certain illustrative aspects of the claimed subject matter are described herein in connection with the following description and the annexed drawings. These aspects are indicative of various ways in which the subject matter may be practiced, all of which are intended to be within the scope of the claimed subject matter. Other advantages and novel features may become apparent from the following detailed description when considered in conjunction with the drawings.
More specifically, disclosed herein is a method for interconnecting microchips comprising: (a) positioning a first microchip using a first manipulator, wherein the first microchip has a set of first nodules located on an edge of the first microchip; (b) securing the first microchip in place; (c) positioning a second microchip using a second manipulator, wherein the second microchip has a set of second nodules located on an edge of the second microchip; (d) moving the second microchip so that the set of second nodules is positioned proximate to the set of first nodules; (e) securing the second microchip in place; and (f) joining the set of first nodules to the set of second nodules to interconnect the first and second microchips.
The set of first nodules can be located closest to a top face of the first microchip. The set of second nodules can be located closest to a top face of the second microchip.
The first microchip and the second microchip can be positioned top-face down on a substrate. The substrate can include a conductive segment or contact that is joined to one nodule of the set of first nodules and one nodule of the set of second nodules when the first second microchips are positioned top-face down on the substrate.
The sets of first and second nodules can maintain the first and second microchips in spaced relation when the first and second sets of nodules and the conductive segment or contact are joined.
The edge of the first microchip can be defined by the intersection of a top face of the first microchip and a side of the first microchip. The edge of the second microchip can be defined by the intersection of a top face of the second microchip and a side of the second microchip.
The first microchip and the second microchip can be positioned top-face down on a substrate. The substrate can include a conductive segment or contact. The method can include joining the conductive segment or contact to one nodule of the set of first nodules and one nodule of the set of second nodules.
Each set of nodules can include at least one nodule.
Also disclosed herein is a microchip unit comprising: a first microchip having a set of first nodules located along and projecting from an edge of the first microchip, wherein the edge of the first microchip is defined at an intersection of a top surface and another surface of the first microchip; a second microchip having a set of second nodules located along and projecting from an edge of the second microchip, wherein the edge of the second microchip is defined at an intersection of a top surface and another surface of the second microchip; and a substrate having a conductive segment or contact. The first and second microchips are positioned top-face down on the substrate with the first and second sets of nodules joined with each other with the first and second microchips in spaced relation and with the conductive segment or contact joined to one nodule of the set of first nodules and one nodule of the set of second nodules.
A surface of at least one nodule of the first set of nodules can be generally coplanar with the top surface of the first microchip. A surface of at least one nodule of the second set of nodules can be generally coplanar with the top surface of the second microchip.
BRIEF DESCRIPTION OF THE DRAWINGS
The systems, devices, and methods may be better understood by referring to the following description in conjunction with the accompanying drawings. The components in the figures are not necessarily to scale and simply illustrate the principles of the systems, devices, and methods. For example, elements in the figures may be exaggerated in size to better aid in the understanding of the portrayed embodiments. The accompanying drawings illustrate only possible embodiments of the systems, devices, and methods and are therefore not to be considered limiting in scope.
FIG. 1 depicts a microchip including edge interconnects or nodules;
FIG. 2 depicts interconnecting two microchips on a substrate via edge interconnects or nodules on each substrate;
FIG. 3 depicts difficulties in interconnecting two microchips of different thicknesses on a substrate, where the edge interconnects or nodules are at different heights from the surface of the substrate;
FIG. 4 depicts interconnecting two microchips of different thicknesses on a substrate via edge interconnects or nodules on each substrate.
FIG. 5 depicts interconnecting two microchips using multiple manipulators;
FIG. 6A depicts two microchips aligned in three-dimensional space;
FIG. 6B depicts the two microchips of FIG. 6A interconnected in three-dimensional space;
FIG. 7 depicts four microchips interconnected or positioned to be interconnected together; and
FIG. 8 is a flow diagram of a method for interconnecting an arbitrarily large array of microchips.
DETAILED DESCRIPTION OF THE INVENTION
It is advantageous to define several terms before describing particular embodiments. It should be appreciated that the following definitions are used throughout this application.
Definitions
Where the definition of terms departs from the commonly used meaning of the term, the definitions provided below are intended, unless specifically indicated otherwise.
For the purposes of the present description, the term “direct electrical connection” refers to the direct contact between interconnect nodules or between an interconnect nodule and an electrical contact so that electrical conduction current may pass between them.
For the purposes of the present description, the term “electronic device” refers to electronic circuitry and any device that includes electronic circuitry. Examples of electronic devices include, but are not limited to, microchips, package systems, transistors, printed circuit boards (PCBs), amplifiers, sensors, inductors, capacitors, electrical connectors into which microchips may be plugged, etc.
For the purposes of the present description, the term “interposer” refers to any structure whose purpose is to extend or complete a conductive electrical connection between two electronic devices. In some embodiments, the conductive electrical connection between interconnect nodules or between an interconnect nodule and a contact may not be direct. For example, in some embodiments, a conductive material, such as solder, may electrically connect two interconnect nodules or an interconnect nodule with an electrical contact. Also, in some embodiments, connectors of various types may help conductively join interconnect nodules.
For the purposes of the present description, the term “microchip” refers to any kind of chip having microfabricated or nanofabricated systems built thereon. Microchips include not only conventional integrated circuits but also Microelectromechanical Systems (MEMS) chips and other related technologies.
For the purposes of the present description, the term “complementary nodules” refers to two microchips containing nodules arranged in a mirrored pattern to one another. In other words, two microchips with complementary nodules are capable of being aligned to form an electrical connection between the two microchips via the nodules.
DESCRIPTION
Aspects of the system and methods are described below with reference to illustrative embodiments. The references to illustrative embodiments below are not made to limit the scope of the claimed subject matter. Instead, illustrative embodiments are used to aid in the description of various aspects of the systems and methods. The description, made by way of example and reference to illustrative reference, is not meant to being limiting with regards to any aspect of the claimed subject matter.
Devices and methods described in this application are particularly well-adapted for use in joining microchips manufactured with solid edge-to-edge interconnects, such as Quilt Packaging® interconnect technology, and will be described in that context. However, it will become apparent that this description is not illustrative of the only utility of the described devices and methods.
The assembly of advanced system-in-package (SiP) designs using innovative packaging and interconnect technology requires substantial innovation in assembly and handling tools and methods. Current approaches for assembling and packaging microchips are wholly unsuited for advanced SiP designs. Accordingly, there exists a long-felt but unaddressed need for improved apparatuses and methods for precisely and reliably assembling advanced SiP designs.
FIG. 1 depicts a microchip 100 configured with solid edge-to-edge interconnects, such as those employed in microchips configured with Quilt Packaging® interconnect technology and described in U.S. Pat. Nos. 7,608,919 and 7,612,443 to Bernstein et al. which are incorporated herein by reference. “Quilt Packaging” is a U.S. registered trademark of Indiana Integrated Circuits, LLC, U.S. Registration No. 4214679.
As shown in FIG. 1 , nodules 102 made of metal or another conductive material are located along and extend from at least one edge 104 or surface 110 of microchip 100 . These nodules 102 are used to electrically and mechanically connect microchips together, either through a direct electrical connection or via an interposer (such as solder). As shown here, nodules 102 are located near the top face 106 (or surface) of microchip 100 . Generally, nodules 102 are either located contiguous to or a predetermined distance below top face 106 of microchip 100 . The placement of nodules 102 may be standardized for a single microchip (so that all of the nodules are located the same distance below top face 106 ) or across different microchips to facilitate alignment of nodules 102 on different microchips. However, one of skill in the art will appreciate that nodules 102 may be placed at any point along the edge 104 of the microchip 100 , so long as the two microchips to be joined have complementary nodules 102 .
Microchip 100 is depicted in face-up orientation, such that when microchip 100 is placed on a supporting surface 108 , the face closest to the nodules 102 (top face 106 ) is exposed. Conversely, a microchip would be termed face-down if top face 106 (the face closest to the nodules 102 ) were in contact with supporting surface 108 , such that top face 106 was not exposed. Placing two microchips 100 configured with complementary nodules 102 adjacent to one another, such that the nodules 102 of the first microchip 100 contact the nodules 102 of a second microchip 100 , forms a direct electrical connection between the two microchips. Alternatively, the nodules 102 may be positioned such that they are close together but not in direct physical contact, allowing an indirect electrical connection between the two microchips through an interposer (such as solder).
As described hereinafter, microchips may be joined together in a more permanent fashion to form a stable electrical and mechanical connection between them. An arbitrary number of microchips may be joined together to form an arbitrarily large array, allowing for electrical connections between each microchip and its neighbors. To facilitate the creation of electrical and mechanical connections between multiple microchips, in an embodiment, these nodules 102 are created with a coating of solder. This solder may further be used as an interposer to facilitate indirect electrical connections.
Referring to FIG. 2 , in one embodiment, a method is provided for connecting two microchips 200 a , 200 b . A manipulator 204 (such as a vacuum tool or a mechanical probe) places a first microchip 200 a face-up on a substrate 206 and maneuvers microchip 200 a into position. As used herein, the term “substrate” is a supporting surface or stage. Alternatively, first microchip 200 a could be placed into position on a package, for example, to allow two microchips to be simultaneously joined to each other and then immediately sealed into the package. In this instance, the package could be placed on substrate 206 and secured into position prior to the microchip being placed on or in the package.
Once first microchip 200 a has been correctly positioned, it is secured in place. In an embodiment, first microchip 200 a is secured in place by applying vacuum pressure via substrate 206 . For example, holes may be included in substrate 206 through which vacuum may be applied to the back-side of first microchip 200 a . The amount of vacuum applied through each hole or subset of holes may be individually controlled, allowing different amounts of vacuum to exist at different locations on substrate 206 . Accordingly, a higher vacuum pressure could be applied to one microchip while a lower vacuum pressure is applied to a second microchip—preventing the first microchip from moving while requiring a predetermined amount of force to move the second microchip. For example, the necessity of using a predetermined amount of force to overcome the vacuum and move the second microchip would decrease the likelihood of the second microchip accidently moving. Alternatively, first microchip 200 a may be held in place by manipulator 204 or another physical restraint, such as a clip, backstop or brace attached to the substrate 206 .
After first microchip 200 a is secured in place, a second microchip 200 b is then placed on substrate 206 by manipulator 204 and aligned with first microchip 200 a in the y-axis. In an embodiment, second microchip 200 b is lightly restrained against substrate 206 by applying vacuum through holes located in substrate 206 , so as to make it easier to perform the necessary fine adjustments to properly position second microchip 200 b . In another embodiment, physical features on substrate 206 (such as grooves, walls, etc.) are used to properly position second microchip 200 b and prevent it from moving in the y-axis. Manipulator 204 then moves second microchip 200 b along the x-axis until it is in contact with the first microchip. More specifically, second microchip 200 b may be moved along any path until nodules 202 b on second microchip 200 b are in contact with nodules 202 a on first microchip 200 a . In an embodiment, lateral pressure is applied between the first and second microchips 200 a , 200 b (for example, by manipulator 204 ) along the x-axis.
As improper alignment may result in some or all of nodules 202 failing to form electrical or mechanical connections, in an embodiment the alignment of two or more pairs of nodules 202 a , 202 b located at opposite edges of two microchips 200 a , 200 b are checked, for example, through the use of machine vision or electrical testing using a probe. As an example, if microchips 200 a , 200 b are slightly misaligned or if one of the microchips is skewed, a first pair of nodules 202 at one end of the set of nodules could be perfectly positioned for connection while the last pair of nodules (located at the opposite end of the chips) could be significantly misaligned. In an embodiment, larger nodules are created at each edge of the microchip to further facilitate proper x/y alignment.
Referring again to FIG. 2 , second microchip 200 b is then held securely in place similarly to first microchip 200 a . As will be apparent to one of skill in the art, multiple manipulators 204 could be used, for example, to secure or position both microchips 200 a , 200 b simultaneously or to enable microchips 200 a , 200 b to be held in place without the use of vacuum or another physical restraint on substrate 206 .
After the two microchips 200 a , 200 b have both been secured in place to substrate 206 , microchips 200 a , 200 b are connected together, both electrically and mechanically. In one embodiment, microchips 200 a , 200 b are connected through a solder reflow process. Nodules 202 a , 202 b , located along the edges of microchips 200 a , 200 b that are to be joined together, are coated in solder or a similar material prior to positioning the two microchips 200 a , 200 b together. Then, when the two microchips 200 a , 200 b are positioned together, nodules 202 a on first microchip 200 a are placed in contact with nodules 202 b on second microchip 200 b . Localized heat (e.g., from a hot air reflow gun, an infrared reflow gun, a soldering iron, a light bulb, or another localized heat source) is then applied to nodules 202 a , 202 b to melt the solder, allowing the solder on nodules 202 a to melt and merge with solder on nodules 202 b , forming multiple continuous connections between microchips 200 a , 200 b at each pair of nodules 202 a , 202 b . The heat is then removed from nodules 202 a , 202 b , allowing the reflowed solder to cool and solidify into an unbroken electrical and mechanical connection between the two microchips 200 a , 200 b.
Alternatively, heat can be applied to the entirety of both microchips 200 a , 200 b (e.g., by using heaters located in the substrate, heating the air surrounding microchips 200 a , 200 b , or another generalized heat source) to raise the temperature of both microchips 200 a , 200 b to some temperature T1 which is less than the melting point of the solder. A second, localized heat source is then used to raise the temperature of the solder on nodules 202 a , 202 b to a second temperature T2, which is at or above the reflow temperature of the solder. Among other advantages, this enables the solder to melt more quickly and avoids subjecting the entirety of both microchips 200 a , 200 b to high temperatures (such as T2), which could potentially damage microchips 200 a , 200 b . Additionally, a less intense localized heat source may be used to avoid damaging microchips 200 a , 200 b and to consume less power. In another embodiment, nodules 202 a , 202 b on microchips 200 a , 200 b are joined through a welding process, such as laser welding. Alternatively, melted solder or a conductive epoxy can be applied to nodules 202 a , 202 b to form direct or indirect connections between the microchips 200 a , 200 b.
After microchips 200 a , 200 b have been connected together to form a multi-chip device, post-processing, such as packaging, may be performed. If microchips 200 a , 200 b were connected together inside a package, the multi-chip device can then be directly connected to the package through a process such as wire-bonding. Alternatively, the multi-chip device may be encapsulated or otherwise protected by the application of a protective material, such as an epoxy or polymer.
Referring to FIG. 3 , the difficulties inherent to connecting two microchips 300 a , 300 b of different thicknesses is shown. In order to form a reliable electrical connection, nodules 302 a on first microchip 300 a must be properly aligned with nodules 302 b on second microchip 300 b . To form a direct electrical connection, each pair of nodules should be in direct physical contact with one another. Alternatively, an indirect electrical connection can be formed through the use of an interposer, such as solder. This allows an electrical connection to be established even if the nodules are slightly misaligned. As shown in FIG. 3 , when microchips of different thicknesses are to be connected together, it may be difficult or impossible to form a direct electrical connection between microchips 300 a , 300 b by placing them adjacent to one another in a face-up orientation, as nodules 302 a , 302 b will be located at different heights off substrate 304 . Further, as depicted in FIG. 3 , if the distance between the nodules 302 a on the first microchip 300 a and the nodules 302 b on the second microchip 300 b is great enough, it may be impossible to form a reliable electrical connection even with the use of an interposer.
Referring to FIG. 4 , a method of joining two or more microchips 400 a , 400 b of different heights to form a microchip unit is described. A first microchip 400 a is placed face-down on a substrate 406 (e.g., a stage, package, or printed circuit board) by a manipulator 404 and maneuvered into position. The substrate 406 may be composed of a material to which solder will not adhere (e.g., a non-metallic compound) to avoid having the microchips 400 a , 400 b inadvertently connected to the substrate 406 . Once it is properly positioned, first microchip 400 a is secured in place. Manipulator 404 then places a second microchip 400 b face-down on substrate 406 , aligns the two microchips 400 a , 400 b , and moves second microchip 400 b such that nodules 402 b are aligned with nodules 402 a on first microchip 400 a . In an embodiment, lateral pressure is applied along the x-axis between the first and second microchips 400 a , 400 b (for example, by the manipulator 404 ). Second microchip 400 b is then held securely in place similarly to first microchip 400 a . As will be apparent to one of skill in the art, multiple manipulators 404 could be used, for example, to secure or position both microchips 400 a , 400 b simultaneously.
As both microchips are located face-down, the nodules 402 a , 402 b are located the same distance above the substrate 406 regardless of whether the two microchips 400 a , 400 b are of equal thicknesses. This allows microchips manufactured from different materials (or wafers of varying thicknesses) to be joined, so long as the microchips have complementary nodules that are manufactured contiguous to or a predetermined distance below the top face of the respective microchip. As described above, modules 402 a , 402 b are then joined (e.g., by using solder reflow).
Also or alternatively, substrate 406 may include a conductive segment or contact 410 positioned in alignment with nodules 402 a , 402 b when microchips 400 a , 400 b are positioned as shown in FIG. 4 . In an embodiment, conductive segment or contact 410 may be connected to one or more other electronic devices of substrate 406 or disposed on substrate 406 . In an embodiment, conductive segment or contact 410 may be a conductive trace or contact on substrate 406 which in an embodiment may be a printed circuit board. Once nodules 402 a , 402 b are located in alignment with conductive segment or contact 410 as shown in FIG. 4 , nodules 402 a , 402 b and conductive segment or contact 410 are joined electrically in any suitable and/or desirable manner (e.g., via solder reflow). An advantage of nodules 402 a , 402 b in alignment with conductive segment or contact 410 is the facilitation of the visual inspection of nodules 402 a , 402 b and conductive segment or contact 410 after joining together, rework of a faulty joining together, and spacing between microchips 400 a , 400 b while simultaneously forming an electrical connection between nodules 400 a , 400 b and conductive segment or contact 410 thereby facilitating a flow of cooling fluid (air) between microchips 400 a , 400 b.
Referring to FIG. 5 , a method of joining two or more microchips 500 a , 500 b of different heights without using a stage or other surface is described. As shown in FIG. 5 , a first manipulator 504 a positions a first microchip 500 a in space. First microchip 500 a is then secured in place (e.g., by locking manipulator 504 a in place). A second manipulator 504 b positions a second microchip 500 b in space. For example, second manipulator 504 b will align the nodules 502 a , 502 b of the two microchips 500 a , 500 b along both the y- and z-axes. As will be clear to one of skill in the art, this allows for microchips of different thicknesses to be easily connected. Second manipulator 504 b is then prevented from moving in the aligned axes. Second manipulator 504 b then moves the second microchip 500 b along the x-axis until nodules 502 b on second microchip 500 b contact nodules 502 a on first microchip 500 a . One or both of manipulators 504 a , 504 b then apply lateral pressure between microchips 500 a , 500 b along the x-axis. Second microchip 500 b is then secured in space (e.g., by locking second manipulator 504 b from moving). Microchips 500 a , 500 b are then joined, for example, via solder reflow.
Referring to FIGS. 6A and 6B , a method of joining two or more microchips 600 a , 600 b into three-dimensional (3D) arrangements is described. A first microchip 600 a is positioned on a substrate 606 using a manipulator 604 and subsequently is secured in place. The first microchip 600 a is created with holes or sockets 602 a located along its top face 608 . In one embodiment, these holes are coated in solder. A second microchip 600 b is then positioned above first microchip 600 a by manipulator 604 . Each of the nodules 602 b along an edge 610 of second microchip 600 b is aligned with respective holes or sockets 602 a on first microchip 600 a . As described above, merely aligning a single nodule-hole pair may cause an inadequate or non-existent connection between some nodules 602 b and holes 602 a if microchips 600 b , 600 a are misaligned or skewed, as other nodule-hole pairs may be misaligned. Accordingly, in an embodiment, two or more nodule-hole pairs located at opposite ends of second microchip 600 b are checked to ensure proper alignment has been achieved.
As shown in FIG. 6B , nodules 602 b on second microchip 600 b are then moved into alignment and contact holes or sockets 602 a on first microchip 600 a and pressure is applied between the two microchips 600 a , 600 b , for example by the manipulator 604 to press nodules 602 b into holes 602 a . The two microchips 600 a , 600 b are then joined, for example by using solder reflow. Additional microchips can then be connected to either the first or second microchip 600 a , 600 b in similar fashion. In an alternative embodiment, first microchip 600 a could be held by a manipulator and positioned in space, without using a stage to support it. Second microchip 600 b could then be aligned and moved into alignment and contact with first microchip 600 a by a second manipulator. This process could be repeated for any number of microchips, thereby creating a three-dimensional array of interconnected microchips.
Referring to FIGS. 7 and 8 , a method of joining an arbitrary number of microchips is described. As shown in FIG. 7 , four microchips 700 a , 700 b , 700 c , 700 d may be joined into a 2×2 array by first creating two pairs 702 a , 702 b of connected microchips—joined together in any manner described herein. Then, the two pairs 702 a , 702 b of microchips are joined together, in any manner described herein, to form a single array composed of four interconnected microchips 700 a , 700 b , 700 c , 700 d.
As will be understood by one of skill in the art, an arbitrary number of microchips could be joined together in any manner described herein together in any manner described herein in similar fashion. For example, a system comprised of an odd number of microchips could be formed by first forming and connecting pairs of microchips and then joining a single unpaired microchip. Similarly, an arbitrary number of microchips of different shapes or sizes could be joined into an interconnected array using this technique. For example, nodules may be located along the interior edges of all microchips in the array, forming electrical and mechanical connections between all adjacent microchips and allowing each microchip to communicate directly with all adjacent microchips. Similarly, microchips may relay signals, so as to allow non-adjacent microchips in the array to communicate. Additional nodules could be formed along exterior edges, for example to allow additional microchips or other electrical devices to be connected to the array.
FIG. 8 depicts a generalized process for creating an arbitrarily large array of interconnected microchips. As described above, in step 800 , two microchips are joined (creating a pair of microchips). At step 802 , a determination is made if additional microchips need to be added to the array. If no microchips need to be added, then the process ends at step 810 . If more microchips need to be added, then a determination is made at step 804 whether there are two or more microchips to add. If so, then two microchips are joined into a pair at step 806 and are added to the array at step 808 . The process then repeats by checking whether more microchips need to be added at step 802 . Alternatively, if there is only a single microchip to add at step 804 , then the single microchip is added at step 812 and the process ends at step 814 .
As will be clear to one of ordinary skill in the art, the process described in FIG. 8 creates an array of microchips that is two microchips wide and an unlimited number of microchips long. Alternatively, the process may be modified to create an array of arbitrary size. For example, a 8×8 array of sixty-four square microchips could be created by first creating thirty-two pairs of microchips, as described above. Each pair (or 2×1 array) is then treated as a single microchip, and paired again to create sixteen 2×2 arrays. The process repeats, successively pairing microchips to create eight 4×2 arrays, four 4×4 arrays, two 8×4 arrays, and finally a single 8×8 array. A similar form of this process could be used to join microchips of any shape into an array of arbitrary size.
What has been described above includes examples of aspects of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art may recognize that many further combinations and permutations of the disclosed subject matter are possible. Accordingly, the disclosed subject matter is intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the terms “includes”, “has”, “having”, or variations in form thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
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Apparatuses and methods related to the field of microchip assembly and handling, in particular to devices and methods for assembling and handling microchips manufactured with solid edge-to-edge interconnects, such as Quilt Packaging® interconnect technology. Specialized assembly tools are configured to pick up one or more microchips, place the microchips in a specified location aligned to a substrate, package, or another microchip, and facilitate electrical contact through one of a variety of approaches, including solder reflow. This specialized assembly tooling performs heating functions to reflow solder to establish electrical and mechanical interconnections between multiple microchips. Additionally, the interconnected microchips may be arranged in an arbitrarily large array.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] None.
BACKGROUND OF THE INVENTION
[0002] Numerous hair curling devices have been introduced over the years. Hair curling devices come in a variety of configurations, sizes and materials. It is well known that the most efficient way to curl hair is with thermal energy. Hair can be curled in the absence of heat if the hair is wrapped around the curling device when it is wet and allowed to dry into a curl. However, waiting for hair to air dry takes a long time, making it inconvenient in today's fast paced world. In addition, rollers can be uncomfortable to wear, especially for long periods of time while waiting for hair to dry.
[0003] Most of the prior art hair curling devices employ an electrical heating means. A curling iron, while effective at curling hair quickly, gets extremely hot and can burn the hair and blister the skin, making it dangerous for the elderly and the young to use. In addition, a curling iron takes a long time to heat, possibly exposes the user to electric shock, and limits the user's movement to the range of the electric cord. Hot rollers, while they do not readily burn the skin or limit movement, are very hot to the touch and therefore hard to handle. In addition, hot rollers are heavy and have a tendency to fall out of the hair.
[0004] Microwave energy has been used as a means for heating hair curling devices. U.S. Pat. Nos. 6,064,051; 6,079,422; 5,988,182 and 6,352,080 provide curlers which may be heated directly in the microwave. The known curlers contain a microwave heatable material which transfers energy from the curler to the hair, causing the hair to curl. The curlers hold the hair in place with pins, clips, ties, surface protrusions or combs. In these cases, individual curlers are heated one at a time, immediately before being placed in the hair. If not placed immediately in the hair after being heated, the heat will dissipate from the curlers into the atmosphere. Also, the process of clipping, tying, or pinning the curler in place is cumbersome if being done by one person. This makes the process of heating and setting hair especially time consuming. Another problem with the prior art microwavable hair curlers is that they can be easily lost or misplaced.
[0005] It is well known in the art of cosmetology that curling hair at higher temperatures results in longer lasting curls. Unfortunately, heat is also known in the art to dry hair out, eventually causing split ends and breakage. In addition, heat can be dangerous to the skin. Thus, there continues to be a need for a hair curling device whose use of heat does not dry out the hair, is warm (not hot) to the touch, is capable of withstanding high temperatures without melting or scorching and is simple to wrap hair around and hold in place. The cylindrical roller shape of most prior art curlers gives the hair rigid, symmetrical and ultimately unnatural looking curls. In addition, though hair curlers specifically designed for microwave heating are known in the prior art, they are to be heated individually in the microwave oven in a cumbersome and time-consuming process. None of the prior art microwavable hair curling devices have been satisfactory. Thus, there exists a need for a hair curling system which is effective at curling, gentle on the hair, easy, safe and time-efficient to use, and capable of producing relaxed and natural looking curls.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention includes a microwavable hair curling device comprising a plurality of hair curlers for winding up human hair. Each curler contains a heat absorbent material which is surrounded by an elongate casing of flexible material with opposite first and second ends, and an axial length. The first and second ends of the curler are attachable to each other. The curlers are both stored and heated inside a carrier which functions as thermal insulating blanket. The thermal blanket insulates the curlers from heat loss when taken out of the microwave. The present invention also includes a method of curling human hair with a microwavable hair curling device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a perspective view of the hair curling device.
[0008] [0008]FIG. 2 is a perspective view of the carrier in a fully unrolled configuration exposing a set of microwavable hair curlers.
[0009] [0009]FIG. 3A is a side view of one embodiment of a hair curler of the present invention.
[0010] [0010]FIG. 3B is a perspective view of a section of the hair curler of FIG. 3A.
[0011] [0011]FIG. 4 is a perspective view showing the carrier in a partially unrolled configuration.
[0012] [0012]FIG. 5 is a rear view of a hair curler of the present invention placed in a section of hair.
[0013] [0013]FIG. 6A shows the hair curler placed near the end of a section of hair to be curled.
[0014] [0014]FIG. 6B shows the section of hair being wrapped around the hair curler of FIG. 6A.
[0015] [0015]FIG. 6C shows the ends of the hair curler fastened together alter the section of hair has been fully wrapped around the hair curler.
DETAILED DESCRIPTION
[0016] [0016]FIG. 1 is a perspective view of microwavable hair curling device 10 . Microwavable hair curling device 10 consists of a carrier 12 and a set of hair curlers 14 . Carrier 12 includes a thermal insulating blanket 16 which, as shown in FIG. 1, may be rolled into a cylindrical shape. Blanket 16 has an exterior surface 18 and an interior surface 20 (shown in detail in FIG. 2) made of fire retardant fabric. Straps 22 and 24 are attached on the exterior surface 18 of blanket 16 . Free ends 22 a and 22 b of strap 22 are tied together, as are free ends 24 a and 24 b of strap 24 to hold carrier 12 in its fully rolled cylindrical shape. Devices other than straps 22 and 24 , can be used to hold carrier 14 in its cylindrical shape so long as the device is fire retardant and microwave safe. Other embodiments of carrier 12 can be used as well. For example, blanket 16 may be simply by folded in half so that it forms a flat carrier instead of a cylinder.
[0017] Surfaces 18 and 20 and straps 22 and 24 of blanket 18 are made out of a microwave safe, fire-retardant fabric that is lightweight, flexible, machine washable and capable of withstanding microwave temperatures of at least about 250° F. without scorching or melting. Preferably blanket 16 is made out of fabrics with fire retardant properties such as NOMEX®, NOVEON®, MILLENIA™, KOTHMEX™ or KYNOL™ brand materials. Blanket 16 preferably is capable of withstanding microwave temperatures of at least about 600° F.
[0018] [0018]FIG. 2 shows the interior surface 20 of carrier 12 after thermal blanket 16 is fully unrolled. When blanket 16 is fully unrolled, carrier 12 reveals interior surface 20 , center strap 26 and a set of hair curlers 14 . Center strap 26 runs lengthwise down interior surface 20 of blanket 16 . Hair curlers 14 are held in place under center strap 26 . Curlers 14 will be discussed in more detail with reference to FIGS. 3A and 3B.
[0019] Interior surface 20 of blanket 16 is rectangular in shape having the following features: opposite first and second ends 28 and 30 , opposite first and second side edges 32 and 34 , length 36 , roll axis 38 , width 40 and seam 42 . To reveal interior surface 20 , blanket 16 is unrolled from first end 28 to second end 30 about roll axis 38 . When fully unrolled, interior surface 20 is about 29 inches long along length 36 . Interior surface 20 is about 8 inches wide along width 40 when measured between side edges 32 and 34 . First and second ends 28 and 30 run transverse to side edges 32 and 34 . Interior surface 20 and exterior surface 18 (see FIG. 1) are stitched together at seam 42 .
[0020] Center strap 26 is attached to interior surface 20 at the following five points: 38 , 40 , 42 , 44 and 46 , however different embodiments of the present invention may differ in the number of attachment points, so long as at least one curler 14 is able to fit in between them. In FIG. 2, 15 hair curlers 14 are secured under center strap 26 in between the aforementioned attachment points. When placed under strap 26 , curlers 14 are lined up side-by-side so that they are parallel to first and second ends 28 and 30 of interior surface 20 . Center strap 26 is preferably made out of the same microwave-safe material as blanket 16 . The fabric is lightweight, flexible, machine washable and capable of withstanding temperatures of at least about 250° F. Preferably, center strap 26 is made out of fabrics with fire retardant properties such as NOMEX®, NOVEON®, MILLENIA™, KOTHMEX™ or KYNOL™ brand materials. Hair curlers 14 may be held in place by devices other than center strap 50 so long as the device is microwave-safe, flexible, machine washable, and capable of holding curlers 14 side-by-side along interior surface 20 .
[0021] Attachment points 38 , 40 , 42 , 44 , and 46 of center strap 26 keep curlers 14 organized so that thermal blanket 16 may be easily rolled into a cylindrical shape without curlers 14 falling out and becoming lost or misplaced. Carrier 12 , complete with interior and exterior surfaces 20 and 18 of thermal blanket 16 , center strap 26 and exterior strands 22 and 24 , is designed to be microwave-safe, lightweight and machine washable. In addition, thermal blanket 16 is easy to roll and unroll, safe to use, easy to transport and an excellent place to store curlers in between uses.
[0022] [0022]FIG. 3A shows one embodiment of hair curler 14 . Hair curler 14 comprises the following features: outer casing 50 , axial curler length 52 , body 54 , opposite first and second ends 56 and 58 , first and second seams 60 and 62 , first fastener 64 and second fastener 66 . Hair curler 14 is shaped like a rod and is about 7.5 inches long when measured along axial length 52 and about 1.25 inches in width. Both first end 56 and second end 58 are flat in order to accommodate the placement of first and second fasteners 64 and 66 . The flat first and second ends 56 and 58 each measure about 2.25 long and 1.25 inches wide. The body 54 of curler 14 is not flat and has a total circumference of about 2.5 inches when measured around its center. First and second seams 60 and 62 separate body 54 of curler 14 from flat ends 56 and 58 . The body portion 54 of curler 14 measures about 3.5 inches along axial curler length 52 between first and second seams 60 and 62 . Outer casing 50 of hair curler 14 is made out of microwave safe, fire-retardant fabric that is lightweight, flexible, machine washable and capable of withstanding microwave temperatures of at least about 250° F. Preferably outer casing 50 is made out of fabric with fire retardant properties such as NOMEX®, NOVEON®, MILLENIA™, KOTHMEX™ or KYNOL™ brand materials.
[0023] Fasteners 64 and 66 are preferably made of hook and loop material, capable of withstanding microwave temperatures of at least about 250° F. First fastener 64 is disposed on the top of first end 56 while second fastener 66 is disposed on the bottom of second end 58 . First fastener 64 is preferably composed of tiny loops 68 while second fastener 66 is composed of tiny hooks 70 . Seams 60 and 62 protect ends 56 and 58 of curler 14 from getting too hot and damaging fasteners 64 and 66 . The hook and loop fastening device used in this embodiment may be replaced by other machine washable, microwave-safe fastening devices so long as both ends of the curler are capable of fastening together and the fastener does not melt or scorch under microwave heat.
[0024] [0024]FIG. 3B is a perspective view of a section of the hair curler 14 of FIG. 3A. The cross-section of hair curler 14 shows the following components: Outer casing 50 , body 54 , axial curler length 52 , first and second ends 56 and 58 , first and second seams 60 and 62 , first and second fasteners 64 and 66 , interior cavity 72 and heat absorbent material 74 . Outer casing 50 is the outermost layer of curler 14 and covers the entire curler 14 . Interior cavity 72 forms the inside of body 54 . Interior cavity 72 is filled with heat absorbent material 74 , preferably in the form of silica beads or other desiccant material.
[0025] A heat absorbent material 74 fills interior cavity 72 of hair curler 14 . Heat absorbent material 74 includes but is not limited to silica beads, buckwheat, flax seed, thermal gel, and any other desiccant material capable of releasing moisture when heated in the microwave. In one embodiment, heat absorbent material 74 is in the form of silica beads, specifically SiO 2 99.5%; Na 2 O 0.021%; Fe 2 O 3 0.02%; MgO 0.01%; Ca 0.04%; A 12 O 3 0.16%, and other compounds 0.01%. The grain size of each silica bead can vary from about 0.5 to 5.0 mm in diameter.
[0026] Silica beads are preferably used as heat absorbent material 74 because as a desiccant they adsorb moisture at room temperature and release moisture upon being heated in the microwave at temperatures of approximately 250° F. to 350° F. When using the preferred embodiment of the present invention, post-microwaved silica beads release moisture and heat through outer casing 50 of hair curler 14 into the hair shaft. Thus, hair curler 14 , when used according to the present invention, both moisturizes and curls hair at the same time. Once hair cools, which takes about five minutes, the curls are set and the curlers may be removed.
[0027] Hygiene is important in personal care, especially if several people in a family are using the same styling tool. Styling products, such as hair spray and gel, can build up on hair curling tools. The build up of old styling product on hair curling tools is unhygienic and not good for styling performance reasons. Fire retardant fabric and silica, as used in the present invention, are machine washable and make curling hair with the present invention more sanitary than conventional methods. In addition, fabric is gentle on the hair, unlike bristles, plastic and metal styling tools. Because the outer casing 50 of curler 14 is made of soft fabric and the shape of the curler 14 is not cylindrical, each curl produced by the present invention is unique—unlike curls produced by roller cylinders of consistent form and uniform shape.
[0028] To use the microwavable hair curling device 10 , carrier 12 is placed in a microwave oven in its fully rolled configuration. Once heated to a temperature capable of curling human hair, about two to three minutes on high heat, the rolled up carrier 12 is taken out of the microwave, untied and unrolled to expose one curler at a time. FIG. 4 is a perspective view of carrier 12 being used according to the present invention. FIG. 4 shows the following features: thermal blanket 16 , strap 22 and its free ends 22 a and 22 b , strap 24 and its free ends 24 a and 24 b , exterior surface 18 , interior surface 20 , center strap 26 , first end 28 , length 36 , roll axis 38 , and curlers 14 . Once carrier 12 is taken out of the microwave, free strands 22 a and 22 b and 24 a and 24 b are untied. Carrier 12 is then opened by unrolling thermal blanket 16 from first end 28 to second end 30 down its length 36 . Carrier 12 is preferably unrolled slowly so that only one curler is exposed at a time. FIG. 4 is an example of how carrier 12 is unrolled to reveal just one curler 14 at a time. FIG. 4 shows one curler 14 held in place against interior surface 20 under center strap 26 . The remaining curlers 14 , remain wrapped inside the rolled portion of carrier 12 where they stay warm while awaiting use.
[0029] To use the present invention, human hair is first divided into sections that the user wishes to curl. Immediately after exposing a warm curler 14 as shown in FIG. 4, said curler is removed from carrier 12 and placed in the section of hair the user wishes to curl, as shown in FIG. 5. FIG. 6A through FIG. 6C show the steps involved in using the present invention after a warm curler 14 has been removed from carrier 12 . FIG. 6A shows curler 14 placed at the end of a section of hair that a user wishes to curl. FIG. 6B shows wrapping a section of hair around the outer casing 50 of curler 14 . Hair may be wrapped in either direction, over or under curler 14 , depending on the desired curl. Once a section of hair is fully wrapped around curler 14 , the curler is fastened together to hold the curl in place. FIG. 6C shows a rear view of a user securing curler 14 in place by bending curler 14 along its axial length 36 and attaching fastener 64 to fastener 66 . Because hair is wound multiple times around hair curler 14 (see FIG. 6B and FIG. 6C), curler 14 will not fall out. Curler 14 is lightweight and easy to fasten in place. For each additional section of hair a user wishes to curl, another warm curler is removed from carrier 12 while the remaining curlers stay warm inside carrier 12 . Steps in FIG. 6A through FIG. 6C are repeated for each additional hair section. Once the wrapped hair cools (approximately 5 minutes), curlers 14 are removed, leaving a natural wavy curl that is easy to style.
[0030] The present invention provides a fast, safe, clean and easy way to curl hair. Whereas previous hair curling devices were effective at curling hair, their intense heat dried out the user's hair and posed a risk of burning the user's skin. In addition, devices heated with electrical heat put the user at risk of electrical shock and limited the user's movement to the range of the electric cord. The present invention solves these problems by providing a hair curling device whose use of heat does not dry out the hair, is warm (not hot) to the touch and is simple to wrap hair around and hold in place. In addition, the carrier of the present invention solves the cumbersome and time-consuming process of having to heat individual curlers in the microwave one at a time. The carrier allows all curlers to be heated together in the microwave in one easy step, and prevents the curlers from losing heat when they are taken out of the microwave. The carrier also provides a place to store curlers between uses so that the curlers are not lost or misplaced.
[0031] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A microwavable hair curling device comprising a plurality of hair curlers for winding up human hair. Each curler contains a desiccant material which is surrounded by an elongate casing of flexible material with opposite first and second ends, and an axial length. The first and second ends of the curler are attachable to each other. The curlers are both stored and heated inside of a microweavable carrier. The microwavable carrier insulates the curlers from heat loss, when taken out of the microwave.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to improved brakes.
(2) Description of the Prior Art
Conventional disc brakes comprising opposed actuator plates, steel balls movable in inclined ramps located in adjacent faces of the opposed actuator plates, rotating brake discs and non-rotatable stationary discs operate when a brake pedal connected by a linkage to the actuator plates to rotate relative to each other, which causes the steel balls to roll on the inclined ramps and thus push the actuator plates apart. This results in clamping the two sets of brake discs (i.e. stationary and rotatable) together to give a braking action.
However such conventional disc brakes have been found to be relatively disadvantageous in relation to uneven distribution of load when the stationary brake disc and the rotatable brake disc were clamped together which caused uneven wear on the brake linings. Also conventional disc brakes as described above tend to have the friction linings on the brake discs wearing out rather quickly with a need for consequential replacement.
Also when conventional disc brakes become well used, the steel balls will tend to wear a track in the ramps, and consequently increase the likelihood of the brakes jamming. One solution adopted to overcome this problem was the provision of raised lugs designed as wear bushings. Once the actuator plates were assembled inside a housing the lugs then fitted neatly in the housing. When the actuator plates are turned, the lugs then were designed to constantly assist in keeping the plates in the correct orientation (i.e. "true" or in line). The steel balls were also supposed to assist. However, it was found when the brakes became well used that the lugs were worn down and made a groove in the housing as well as the balls making a track in the ramps. Therefore eventually the friction discs jammed. Also the actuator plates jammed because they never seemed to remain parallel to each other and geometrically at right angles to their rotational plane at the same time. Thus the balls and lugs wore down after use, and the load stress points under rotation were concentrated in too small an area.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to provide brakes which alleviate the above-mentioned problems.
Another object of the invention is to provide brakes which are particularly well suited to trailers or caravans, but are also applicable to other vehicles, the brakes being particularly efficient, self-adjusting, and not liable to damage due to ingress of water, dust or other foreign matter.
Accordingly, the invention provides a brake assembly including a brake housing; a wheel shaft rotatable in the housing; an armature plate in the housing, secured to and rotatable with the shaft; a movable actuator in the housing movable rotatably from an inoperative position to an operative position closer to the armature plate; electromagnetic means adapted, when energised, to urge the actuator to rotate, with the armature plate, from inoperative to operative position; a rotatable brake disc in the housing, rotatable with the shaft; and a non-rotatable brake member in the housing; the actuator being adapted, when moved to operative position, to force the rotatable brake disc and the non-rotatable brake member into frictional contact to brake the rotation of the said disc and the shaft to which it is connected.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In order that exemplary embodiments will now be understood, reference is now made to the accompanying drawings, wherein:
FIG. 1 is a front view of the brake assembly in accordance with the invention;
FIG. 2 is a front view of the rear housing component of the brake assembly of FIG. 1;
FIG. 3 is a view along line A--A of FIG. 2;
FIG. 4 is a view of the actuating mechanism of the brake assembly of FIG. 1 which moves the movable actuator from the inoperative to the operative position;
FIG. 5 is a view of the movable actuator of the brake assembly of FIG. 1;
FIG. 6 is a view along line B--B of FIG. 5;
FIG. 7 is a view along line A--A of FIG. 5;
FIG. 8 is a side sectional view of the brake assembly of FIG. 1;
FIG. 9 is an exploded view of the brake assembly of FIG. 1;
FIG. 10 is a side sectional view of a modification of the brake assembly of FIG. 8; and
FIG. 11 is a side sectional view of another modification of the brake assembly of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in the drawings and in particular in FIG. 9, the brake assembly of the invention includes wheel hub 10 which is attached to drive shaft 21 by bolts 11. There is also provided wheel studs 12 which project outwardly through mating slots in wheel hub 10, and bolts 14 attaching cover plate 13 to the remainder of the brake housing. Bolts 14 fit through threaded holes 14A in cover plate 13.
Cover plate 13 also includes a shoulder or ledge 16A for accommodating bearing cone 16 and bearing cup 15. A seal 16B is also provided which locates on the front side of shoulder 16A as shown in FIG. 9.
Cover plate 13 may be bolted to a rear housing component 38 through bolts 14 which also engage in threaded holes 14B in component 38. In fact there is provided a peripheral flange 13A which engages with enlarged area 13B of peripheral flange 38A of rear housing component 38.
There is also provided bearing or bush 17, non-rotatable brake discs 18 which have a notch 18A to engage with a pin or appropriate part of the housing to prevent rotation, rotatable brake discs 19 having friction faces on both sides as shown, and a rotatable armature plate 20 having a frictional face or lining on its front face only as shown.
The brake assembly also includes a rotatable drive shaft 21 which is splined at 22 and threaded holes 11A for bolts 11 which interconnect shaft 21 with wheel hub 10. Another set of bearing cup 15 and bearing cone 16 is provided and also sealing gaskets 23.
There is also shown annular electromagnet 24 which is mounted in retaining plate 26. Electromagnet 24 is connected by line 25 to an appropriate source of power supply. Movable actuator plate 29 is attached to plate 26 via pin 28 which engages in bush 27. Pin 28 is welded or otherwise attached to plate 26 at dimple 28A.
Actuator plate 29 also includes rack 36, spring hole 31B, steel ball recess 37A, and spring retainer 30B. There is also shown slot 29B for bush 27 and shoulder 29A.
There is also shown lever arm 32 having pinion 35, slotted area 33, depending pin 34 and spring hole 31A whereby lever arm return spring 31 engages in both holes 31A and 31B.
Rear housing component 38 also has steel ball recess 37B, enlarged central body portion 39, peripheral flange 41, shoulder 40 and hole 30A for engaging with spring 30. There is also shown steel balls 37.
Also shown is lever 44 having a retaining cotter pin 45, and seal 43. Lever 44 fits over lever arm 32 and is retained in position by cotter pin 45. Shoulder 16A accommodates bearing cone 16.
The brake assembly housing defined by components 13 and 38 is substantially cylindrical and is fixed to an axle of a vehicle or otherwise to the vehicle's frame or chassis. Shaft 21 rotates in bearings formed by cone 16 and cup 15. A wheel (not shown) may be attached to wheel hub 10. The housing is filled with oil, and seals 16B and 43 prevent the escape of oil or ingress of dust or water. Sealing gaskets 23 may be used as adjusting shims to correctly preload the tapered bearings formed by cone 16 and cup 15. Discs 18, 19 and 20 are free to move on shaft 21 a limited distance rearwardly or frontwardly. Discs 18 cannot rotate because pin 34 engages in notch 18A.
The movable actuator plate or ring 29 and rear housing component 38 hold between them four balls 37 in equally spaced arrangement, each of the balls being partly within recess 37B in the rear housing component 38 and partly within recess 37A in the movable actuator ring 29. Each of these recesses is elongated, its major axis being substantially tangential to a circle centred on the axis of the ring, is of arcuate cross-section, and diminishes in depth from the middle to both ends. The two members 29 and 38, and their recesses, are such that when the movable ring 29 is at its median or inoperative position, each of the balls 37 is in the deeper middle parts of the two recesses 37A and 37B, and actuator ring 29 is fairly close to rear component 38; and when the movable actuator ring 29 is rotated to full extent in either direction, to either of its two operative positions, each of the balls 37 is rolled into shallow end parts of the two recesses 37A and 37B, and the actuator ring 29 is spaced furthest apart from housing component 38. The tension springs 30 interconnect the two members 29 and 38 and bias the movable ring 29 to its median or inoperative position.
The ferrous rotating armature plate 20 is made for engagement with the splines 22 of the shaft 21, and so rotatable with and slidable along the shaft.
In operation of the brake assembly as shown in FIGS. 1-9, when the brake assembly is operated by a rheostat, controller operated by a foot pedal, (or alternatively by a dyno system built into rotation of shaft 21 or any other suitable means) the electromagnet 24 is energised, further depression of the pedal increasing the amperage. The electromagnet 24, when energised, is attracted to rotating armature plate 20, and consequently torque is applied to plate 20. This in turn causes rotation of plate 26 which commences to rotate around shoulder 29A of actuator plate 29.
Bush 27 then rotates on pin 28 which is directly attached to plate 26 at 28A. The assembly of pin 28 and bush 27 then commences to rotate with plate 26 through slot 27A shown in FIG. 4. This assembly then engages with the periphery of slot 33 located in lever 32 and thus lever 32 moves which in turn causes movement of pin 34 which is integral with pinion 35. Pinion 35 then meshes with rack 36 which is integral with actuator plate 29. Plate 29 then rotates in the opposite direction to movement of pinion 35 and this causes movement of balls 37 from the inoperative to operative position as previously described. Then actuator plate 29 moves towards discs 18 and 19 causing frictional engagement between these discs. The braking effect is enhanced by the rotational movement of shaft 21.
The stationary discs 18 and rotatable discs 19 may have oil dispersal slots and holes provided in them (not shown) to assist in dispersal of oil away from the mating frictional surfaces of discs 18 and 19.
If desired the actuator plate 29 may be moved mechanically from the inoperative to the operative position and this may be achieved by movement of lever arm 44. Lever arm 44 has pin 45 attached thereto which must travel in a specified arc before engaging the periphery of slot 46 (shown in FIG. 4) and thus actuating pinion 35 which then causes movement of plate 29 as previously described. Thus the provision of lever arm 44 is useful as an emergency brake or hand brake.
The brake assembly illustrated in FIG. 10 includes a substantially cylindrical housing 50, closed at its outer end, its inner end being closed by an end plate 51 bolted to a peripheral flange about the housing. This housing is fixed to an axle of the vehicle or otherwise to the vehicle's frame or chassis. A shaft 52 is rotatable coaxially in the housing, in anti-friction bearings 53 in the housing and the end plate 51, and has at its outer end an attachment flange 54 to which a wheel (not shown) may be secured, a retainer 55 bolted to the inner end preventing the disengagement of the shaft. The housing is filled with oil, and appropriate oil seals 56 are provided to prevent escape of the oil or ingress of dust or water.
Coaxially mounted within the housing are a fixed actuator ring 57 and a movable actuator ring 58. The fixed actuator ring 57 is engaged upon an annular shoulder 59 on the closed end of the housing 50 and secured by screws (not shown), and is formed with a downwardly extending lug 60 with a notch 60A which is closely engaged by a pin 61 fixed in the housing and restraining the actuator ring 57 against rotation. The movable actuator ring 58 is also formed with a downwardly extending lug 58A with a notch 58B engaged with the pin 61, but in this case the notch 58B is wider, to permit the movable actuator ring a degree of rotational movement.
The fixed and movable actuator rings 57 and 58 hold between them four balls 63 in equally spaced arrangement, each of the balls being partly within a recess 64 in the fixed actuator ring 57 and partly within a recess 65 in the movable actuator ring 58. Each recess 64 and 65 is similar to recesses 37A and 37B described previously and ring 58 moves from an inoperative position to an operative position by movement of steel balls 63 in the same manner as movable actuator 29 relative to rear housing 38 as described previously.
The shaft 52 is splined, as indicated at 67, and there is mounted on the shaft adjacent to the housing end plate 51 a ferrous rotating armature plate 68, which is made for engagement with the splines of the shaft, and so rotatable with and slidable along the shaft. The movable actuator ring 58 is formed with two diametrically opposed lugs 69 through which are secured a pair of parallel pins 70 extending towards the armature plate 68, and on each of these pins there is slidably mounted an annular electromagnet 71, a compression spring 72 on the pin between the actuator ring and the magnet urging the magnet into contact with the armature plate.
Between the movable actuator ring 58 and the armature plate 68 is an annular brake ring 73 having a downwardly extending lug 74 notched for engagement with the pin 61, which restrains this brake ring against rotation.
Two similar brake discs 75 are provided, one between the armature plate and the brake ring 73, the other between this brake ring and the movable actuator ring. Each of the brake discs 75 is engaged with the splined shaft 52 for rotation with the shaft, and is slidable along the shaft. Each of the said discs is provided on both sides with annular sintered friction faces.
The brake in FIG. 10 may be operated by a foot pedal as described previously so that, when the pedal is depressed, the electromagnets 71 are energised, further depression of the pedal increasing the amperage. The magnets, when energised, are attracted magnetically to the rotating armature plate 68, and consequently torque is applied to the movable actuator ring 58 on which the magnets are mounted. The consequent rotational movement of the movable actuator ring to an operative position results in the balls 63 being rolled to shallow ends of the fixed and movable actuator rings 57 and 58 to move the ring 58 axially away from the ring 57, and to apply pressure to the arrangement of brake discs 75 and brake ring 73 between the movable actuator ring 58 and the armature plate 68. Friction between the movable actuator ring 58 and the near brake disc 75 applies further torque to the ring 58. The braking effect therefore will be very efficient.
It will be appreciated that the braking is applied equally to rearward motion as to forward motion of the vehicle.
In a modification of the invention shown in FIG. 11 the brake housing consists of two parts 50A and 51A both similar to housing parts 50 and 51 before described in FIG. 10 but arranged and bolted together to provide a housing of greater depth. In this embodiment the inner surface of housing part 50A contains recesses 64 and is therefore the equivalent of fixed actuator ring 57 described previously which was separate from the housing. Part 50A functions with associated movable actuator ring 58 and interposed balls 63 as before described. It will be noted in FIG. 11 that the same numerals are used to designate the same members as in FIG. 10.
The rotating armature plate 68 in this embodiment is located centrally within the housing as shown and two arrangements of rotating brake disc 75 with friction faces 78 and nonrotating brake ring 73 is shown. The movable actuator ring 58 is provided with an electromagnet 71 which is a single large annular magnet coaxial with movable actuator ring 58 and secured in an annular recess therein. The brake is applied by energising magnet 71 which is in magnetic engagement with armature plate 68.
It will be noted that in the FIG. 11 embodiment the retainer 55 is dispensed with the shaft 52 being larger at the centre than at the ends. Also the attachment flange 54 has been dispensed with and replaced by a separate attachment plate 54B which is bolted to shaft 52 as shown. These changes facilitate assembly of the braking system such as from the end defined by plate 54B and one can use variable size attachment plates to suit differently sized wheels.
In FIG. 11 the cam 76 is used to work the hand-brake only. The cam can also be used to function as an emergency brake. The cam lever 79 on shaft 80 works in the same fashion as pin 61 in FIG. 10 previously described but it may be held in an appropriate position by spring tension. By connecting a suitably set trigger device to lever 79 via a cable, the cam 76 could be used to apply the brakes mechanically by the lever pulling lever 79. This is useful for safety purposes with the cam providing a mechanical back up for the electromagnet system. The cam 76 engages in notch 77 in movable actuator ring 58 so that when the lever 79 is moved by the hand brake lever (not shown) the ring 58 is turned to apply the brake. In FIG. 11 there is also shown bearings 81 and seals 82.
In comparing the respective embodiments of FIGS. 1-9, 10 and 11, it is believed the leverage advantage of FIGS. 1-9 requires less effort than through the cam method shown in FIG. 11.
In the FIGS. 1-9 embodiments, when plate 13 is bolted to rear housing 38 and the correct shims 23 are used in conjunction with tapered bearings then shaft 21 in the form of a tubular sleeve will rotate coaxially and cannot disengage. The two members 13 and 38 are bolted in such a way so as to set the correct amount of preload on the bearings (e.g. by shims which also serve as sealing gaskets). Thus the need for threads, lock nuts etc. are substantially eliminated.
Also the FIGS. 1-9 embodiments show how it is practical to mount the cover plate 13 on a suitable axle and assemble the whole brake from the front in sequence.
It will also be appreciated that shoulder 41 is useful in ensuring that ring 29 rotates equally, evenly and symmetrically and forms the correct support for pin 34 and balls 37.
The outside of the housing may be fitted with fins for cooling purposes and the interior surface may have raised fins to locate the stationary discs 18.
If desired, hydraulic or other means may be provided for turning the movable actuator ring to apply the brake.
As shown in FIGS. 1-9 shaft 21 is in the form of a tubular sleeve which allows for insertion of the sleeve over a stub axle or protruding wheel axle and thereby this allows for the attachment of the brake of the present invention to existing wheel axles.
It will be appreciated that if desired the rotatable discs and stationary discs may be provided in the central part of the brake housing and a pair of movable actuators provided bounding the assembly of rotatable and stationary discs at each end of the housing wherein the steel balls engage in their corresponding recesses between each movable actuator and each end of the housing.
Brakes according to the invention will be found to be very effective in achieving the objects for which they have been devised. It will, of course, be understood that the particular embodiments of the invention herein described by way of illustrative example only may be subject to many modifications of constructional detail and design, which will be readily apparent to persons skilled in the art, without departing from the scope and ambit of the invention.
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This invention relates to a brake assembly having a brake housing and wheel shaft rotatable in the housing. There is provided an armature plate in the housing secured to and rotatable with the shaft. Also provided is a movable actuator in the housing movable rotatably from an inoperative position to an operative position closer to the armature plate. An electromagnet is provided either directly mounted to the movable actuator or indirectly via a mechanical linkage. When the electromagnet is energized it causes the actuator to rotate with the armature plate and thereby move to an operative position where it forces a stationary brake disc and rotatable brake disc into engagement to achieve a braking action. This engagement is released upon de-energization of the electromagnet.
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FIELD OF THE INVENTION
[0001] This invention relates to a terrestrial wavelength-division multiplexing (WDM) system in which the transmission is bidirectional along a single optical waveguide, such as a fiber.
BACKGROUND OF THE INVENTION
[0002] The demand for increasing channels in optical WDM systems has created interest in bidirectional systems in which a single wave guide, such as a fiber, is used to transmit optical signals in the two opposite directions along the fiber essentially to double the number of channels that can be transmitted along the fiber. There have been two principal issues that need to be addressed in the design of such systems. First there needs to be a wavelength channel allocation plan that provides adequate isolation between channels with a minimum of overlap. To this end there needs to be provided adequate spacing in the wavelengths of adjacent channels to maintain the necessary isolation between the channels. An important consideration has been the need to avoid especially four-photon mixing (FPM) between adjacent channels traveling in the same direction, a factor which imposes a limit on the spectral density of the system, where spectral density is defined as the number of channels that can be transmitted within a unit spectral interval under essentially error-free conditions. As is known, each set of two codirectional WDM channels generates multiple new optical signals overlapping in frequency with adjacent channels, thus generating in-band crosstalk that reduces error-free transmission. The efficiency of the FPM process for generating intervening channels is directly dependent on the wavelength spacing among the WDM channels. Low FPM penalty requires wide channel spacing among WDM channels for signals traveling in the same direction. However, counterdirectionally propagating channels do not contribute significantly to the FPM process so that the spacing in an equidistant WDM grid can be halved without an observable increase in the FPM penalty if one interleaves a set of counterpropagating WPM channels. This channel structure is known in the art as an interleaved bidirectional WDM architecture and allows for spectral densities essentially double those feasible for a comparable unidirectional channel structure.
[0003] However an interleaved bidirectional WDM architecture still requires separate transmitters, receivers and compound amplifiers to provide gain in each of the two opposite directions.
[0004] A problem that arises in such an architecture is that a signal propagating in a given direction will inevitably experience factors that result in some reflection of the signal that will cause part of it to travel in a direction opposite, or counter, to its original direction of propagation and so to affect deleteriously the signals of channels launched to propagate in such opposite direction. Such energy will be described as counterpropagating or counterdirectional energy.
[0005] Accordingly, design of a bidirectional interleaved WDM system requires special consideration, particularly in the construction of the optical amplifiers of the system, since they are generally used to provide both channel amplification and channel isolation among counterpropagating sets of channels.
[0006] The present invention presents a novel approach to the isolation need of counterpropagating reflected energy in such bidirectional WDM systems.
SUMMARY OF THE INVENTION
[0007] The invention provides novel forms of optical amplifier architecture to neutralize counterpropagating signals. More particularly, the invention involves inserting along the light wave paths suppression filters of appropriate spectral form, to be termed interleavers, to selectively pass in a given direction only one of the two sets of interleaved channels. In a preferred form, the interleaver is a four-port filter that passes channel signals of a first of two sets of spectrally interleaved signals that propagates in a given direction from an input port to an output port and continues the light appropriately along a path in the desired direction, but shunts counterdirectional propagating light entering the same input port to a different output port for attenuation or absorption. A device, typical of the kind that can serve as the interleaver, is the chromatic dispersion-free Fourier transform-based wavelength splitter described in a paper entitled “Chromatic dispersion free Fourier transform-based wavelength splitters for D-WDM” that was published in the Fifth Optoelectronics and Communications Conference IDECC 2001 Technical Digest, July 2000, pp. 374-375. Various arrangements will be described of particular design to suppress selectively counterpropagating light arising from reflections along the prescribed wave path.
[0008] In particular, a feature of the invention is a gain block for use in a WDM transmission system in which a first of two sets of optical channels of interleaved wavelengths propagates along a waveguide in one direction with low loss selectively and the second set of optical channels propagates along the same guide with low loss selectively in the direction opposite to the first direction. A characteristic of gain blocks in accordance with the invention is the inclusion of interleaver elements that are basically four-port elements is that the port at which a signal exits is a function both of the port at which it enters and the wavelength of the signal. By such inclusion there is substantially reduced the effect of reflections in the system that give rise to spurious signals that will be described as counterdirectional propagating signals, and that are of the wavelengths to be controlled by the interleaver.
[0009] The invention will be better understood from the following more detailed description taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a wavelength grid of two interleaved sets of equally spaced channels for propagating in opposite directions along a common waveguide, such as an optical fiber.
[0011] [0011]FIG. 2 shows in block diagram form a pair of WDM systems transmitting in opposite directions along a single fiber path in accordance with the prior art.
[0012] [0012]FIG. 3 shows a suitable interleaver in a four-port topological form for separating and/or combining optical channels into two different physical paths for use in the invention.
[0013] [0013]FIG. 4 shows the spectral response desired for the interleaver of FIG. 3 for east to west and west to east propagating of eight interleaved channels.
[0014] Each of FIGS. 5 - 12 is a different example of a gain block suitable for use in a bidirectional optical WDM transmission system in accordance with the invention.
DETAILED DESCRIPTION
[0015] [0015]FIG. 1 is a typical wavelength grid of interleaved channels in a bidirectional transmission system. The set of odd-numbered channels λ 1 , λ 3 , λ 5 , and λ 7 are transmitted selectively from left to right. The set of even-numbered channels λ 2 , λ 4 , λ 6 , and λ 8 are transmitted selectively from right to left. Channel energy of either set traveling in the direction opposite its assigned direction will be described as either counterdirectional or counterpropagating. The channels are desirably spaced apart essentially equally, the assigned wavelength increasing monotonically the higher the channel number.
[0016] [0016]FIG. 2 shows in block schematic form the basic elements of a typical optical bidirectional interleaved optical transmission system 10 in which a number of transmitters 11 A operating at odd-numbered channels supply a multiplexer 12 which combines the channel signals into a multichannel signal for transmission from left to right along the fiber waveguide 14 to the receivers 13 A by way of demultiplexer 15 A. At the other end of the waveguide there are a like number of transmitters operating at the even-numbered channels for supplying the waveguide with signals for transmission from right to left to receivers 13 B. To simplify the disclosure, such signals will be described as two sets of signals of interleaved wavelengths. The fiber is shown separated into three spans 14 A, 14 B, 14 C, although there is no real limit to the number of spans. Between the spans are located bidirectional gain blocks 17 A and 17 B. Each gain block includes a separate unidirectional optical amplifier (OA) for each direction. In addition to the bidirectional gain blocks 17 A, 17 B, separate unidirectional optical amplifiers 19 are positioned in the wave paths ahead of the multiplexers and demultiplexers. Optical routing elements, such as circulators 20 , are included appropriately along the fiber to direct the travel of odd-numbered input channels from left to right and the even-numbered input channels for travel from right to left. When use is being made of only three ports of a router, a three-port router can be used, although in the exemplary embodiments four-port routers are being included. As mentioned earlier, it will be convenient to describe the transmission of the light traveling in the desired direction as codirectional and any light traveling in the direction opposite that assigned, such as light redirected by reflection at a waveguide adjacent in its wave path, as counterdirectional. The gain blocks themselves, for example, may act as discontinuities to provide such reflection. Reflections can occur at various other points along the wave path and give rise to counterdirectional light. In addition, Raleigh-back scatter from the intrinsic nature of the fibers will always exist.
[0017] A difficulty with the basic system shown in FIG. 2 is that light traveling codirectionally along the wave path will tend to experience reflections so as to travel counterdirectionally. Such light will commingle with codirectional light and interact with it in a manner to impair the quality of the codirectional light by generating random crosstalk. It is such problems that the invention seeks to ameliorate.
[0018] [0018]FIG. 3 shows in symbolic form a four-port interleaver 30 of the kind that is used in the invention to ameliorate the problem. Odd-channel light entering at port A exits selectively at port D, while even-channel light entering there exits selectively at port C. Ports A and D shall be described as the assigned ports for signals of the odd-numbered channels and ports A and C as the assigned ports for the even-numbered channels. The operation is reciprocal, odd-channel light entering at port D exits selectively at port A, even-channel light entering at port C exits selectively at port A. Similar functionality exists for port B. Odd channel signals entering at port B will exit at port C, while even channel signals entering at port B will exit at port D.
[0019] [0019]FIG. 4 shows the spectral response desired for an interleaver for use in the invention in which the wavelength of the light is plotted along the X-axis and its transmittance is plotted along the Y-axis. The solid line 41 represents the codirectional transmissivity for the set of odd wavelengths between either of its two assigned pairs, (A-D) or (B-C). As seen, it is high at the odd wavelengths and low at the even wavelengths. The broken line 42 similarly represents the transmissivity for the set of even channels between its assigned pairs (A-C) (B-D). As seen, it is high at the even wavelengths and low at the odd wavelengths. As can be appreciated from the drawing, the two sets of channels have interleaved transmissivity characteristics, the reason for the choice of name for the element.
[0020] [0020]FIG. 5 shows a relatively simple pair gain block 50 for use with the invention for use when the interleavers included possess significant conversion loss even for the codirectional travel of light therethrough since the use permits recovery of the amplifier noise figure and signal power.
[0021] The gain block 50 comprises four optical amplifiers, two poled in each of the two directions. Amplifiers 51 A and 51 B are poled to amplify codirectional odd-channel light traveling from left to right. Amplifiers 52 A and 52 B are poled to amplify even-channel codirectional light traveling from right to left. Interleaver 53 A is interposed between amplifiers 51 A and 51 B. Interleaver 53 B is interposed between amplifiers 52 A and 52 B. Unused ports advantageously are terminated in a non-reflective manner. Amplifier 51 A supplies port A of interleaver 53 A and its port D supplies amplifier 51 B. Amplifier 52 A supplies port A of interleaver 53 C and its port C supplies amplifier 52 B. Circulators 54 A and 54 B are connected to the ends of the waveguide span between which the gain block is inserted. Circulator 54 A supplies input light to amplifier 51 A and circulator 54 B supplies input light to amplifier 52 A. Codirectional traveling light passes selectively through each interleaver and is amplified; most counterdirectional light fails to reach the input of the succeeding amplifier and so is suppressed.
[0022] The gain block 60 shown in FIG. 6 is more suitable for use where the interleaver introduces insignificant loss to codirectional light. In this case, there may be eliminated the optical amplifier ( 51 B, 52 B) used in the FIG. 5 block to amplify the codirectional light passing successfully through the interleaver. Accordingly the path for the codirectional odd-channel light comprises the optical amplifier 61 A and interleaver 63 A and the path for the codirectional odd-channel light comprises the optical amplifier 62 A and the interleaver 63 B. Circulators 64 A and 64 B are included at appropriate ends of the gain block.
[0023] [0023]FIG. 7 shows a gain block 70 that is characterized by the fact that counterdirectional light is blocked before it reaches an optical amplifier of the gain block. In this gain block 70 , the interleavers 71 A and 71 B are interposed at opposite ends of the gain block in the path of optical amplifiers 72 A and 72 B, respectively, to block the entry of counterdirectional light from entry into the amplifier.
[0024] An important consideration in systems in which a number of optical interleavers are cascaded because a number of spans are involved is in their spectral uniformity and isolation depth. FIG. 8 is an embodiment in which the gain block 80 employs a single interleaver, two circulators, a mirror and two optical amplifiers.
[0025] Input odd-channel light from the fiber 81 enters a first port of circulator 82 , exits through the second port of the circulator to enter port D of the interleaver 83 , and exits at port A to be reflected by the mirror 84 back into port A of interleaver 83 for exit at port D, entry into the circulator 82 for exit to enter the optical amplifier 85 for entry into a first port of circulator 86 and exit therefrom at the next port into the fiber 87 .
[0026] The even-channel signals enter from the fiber 87 at the input port of circulator 86 to exit at the next port for travel to port C of interleaver 83 and exit at port A for reflection by mirror 84 back into port A and exit at port C of interleaver 83 . This light then passes again through circulator 86 before entry into optical amplifier 88 . It exits from amplifier 88 for entry into the circulator 82 and exits therefrom into the fiber 81 for travel westward.
[0027] [0027]FIG. 9 shows, as another alternative, an arrangement 90 in which the interleaver is included after amplification of the signals. An input signal of odd channels supplied by input fiber 91 is applied to a port of circulator 92 for entry at port D and exit at port A of the interleaver 93 . After reflection from the mirror 94 it re-enters interleaver 93 at port A and exits at port D back into the circulator 92 for transfer to the optical amplifier 94 for amplification. After amplification it enters circulator 95 and exits into the output fiber 96 .
[0028] Signals of even-numbered channels are supplied from input fiber 96 to circulator 95 for exit into port B of interleaver 97 and exit at port C for reflection at mirror 98 . After reflection the signal re-enters interleaver 97 at port C and exits at port B for entry into circulator 95 . It exits from the circulator 95 to enter into optical amplifier 99 . After amplification the signal enters circulator 92 and exits into output fiber 91 .
[0029] [0029]FIG. 10 illustrates a gain block 100 that provides four passages through separate interleavers for even stronger suppression of crosstalk caused by counterdirectional light.
[0030] Odd-numbered channels propagating to the right are supplied from fiber 101 by way of circulator 102 to the D port of interleaver 103 for exit at its port A. They then enter port A of interleaver 104 and exit at its port D and then pass through optical amplifier 105 A. After amplification they enter interleaver 106 by way of port A and exit at port D to pass on to the interleaver 107 . They enter by port C and exit by port B and then pass through the circulator 108 to the output fiber 109 .
[0031] The even-numbered channels enter from input fiber 109 , pass through the circulator 108 , enter interleaver 107 by way of port A and exit at port C. They then enter interleaver 106 by port D and exit by port B to pass through optical amplifier 105 B. After amplification they pass into interleaver 104 entering at port C and exiting at port A after which they enter interleaver 103 by way of port A and exit therefrom by way of port C. From there they propagate through circulator 102 to output fiber 101 .
[0032] In the case where there are available bidirectional optical amplifiers that can be used for amplification in either direction of travel therethrough by the even- and odd-numbered channels, architecture of the kind shown in FIG. 11 and FIG. 12 becomes feasible.
[0033] In the gain block 110 of FIG. 11, the odd-numbered channels traveling eastward are supplied from input fiber 111 to the port A of interleaver 112 for exit at port D for passage through circulator 113 for travel to the input of the bidirectional amplifier 114 for passage therethrough and into a port of the circulator 115 for exit therefrom and entrance into port A of interleaver 116 for exit at port D and passage into the output fiber 117 for further eastward travel. The even-numbered channels traveling westward are supplied to port D of the interleaver 116 for exit at port B and entrance into a port of circulator 115 for exit therefrom for amplification. Upon exiting from the amplifier 114 , the even-numbered channels enter a port of circulator 113 and exit therefrom to enter port C of the interleaver 112 to exit at port A to continue westward along fiber 111 .
[0034] In the architecture of the gain block 120 of FIG. 12, a mirror is used to replace one of the interleavers and one of the circulators. This may alleviate problems arising from the need of spectral alignment between separate interleavers. In gain block 120 , odd-numbered channels are supplied from input fiber 121 to port A of the interleaver 122 to exit at port D for entrance into circulator 123 for passage therethrough to enter the bidirectional amplifier 124 for amplification. After exit therefrom, the signal light is reflected back by mirror 125 for re-entry into the bidirectional amplifier 124 for further amplification. After amplification, the signal light passes through the circulator 123 and enters port C of the interleaver 122 to exit at port B to pass on to the fiber 126 for further travel.
[0035] The even-numbered channels are supplied by fiber 126 to port B of the interleaver 122 for exit at port D and entry into circulator 123 . From circulator 123 , the light channels pass into the bidirectional amplifier 124 for amplification. After amplification, the exiting light is made incident on mirror 125 for reflection and re-entry into the bidirectional amplifier 124 for further amplification. After amplification, the exiting light passes through the circulator 123 for entry into port C of interleaver 122 and exit therefrom by way of port A into fiber 121 for further travel there along.
[0036] It is to be understood that the various embodiments described are intended to be exemplary of the basic principles involved and that various other embodiments may be devised by a worker in the art without departing from the basic principles of the invention.
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A bidirectional WDM optical system in which crosstalk between interleaved channels of different wavelengths is suppressed by the inclusion in the amplifier gain block of four-port filters that discriminate on the basis of the wavelength of the interleaved signals passing through the four port filters.
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TECHNICAL FIELD
This invention relates to shoes for hoofed animals, and more particularly to a shoe and method of shoeing hoofed animals using ultraviolet-cured acrylic material.
BACKGROUND ART
For years farriers have practiced the skill of shoeing hoofed animals with no substantial changes in the techniques employed. The usual procedure of shoeing a hoofed animal is to trim the keratinous portion of the hoof to the required length, and then an iron shoe is forged to match the trimmed hoof. Once the shoe has cooled, the shoe is attached to the hoof utilizing nails hammered through holes in the shoe into the hoof so that the nails project through the hoof wall. The projecting nails are then cutoff and cleated over as necessary.
The above process is generally most satisfactory, however, this method can cause many foot and leg ailments in the animal. For example, if when shoeing, a nail penetrates the sensitive part of a foot or if the animal casts off a shoe, leaving some nails projecting from the bottom of the hoof and on which the animal subsequently steps acute problems can be caused. Furthermore, an animal with brittle horn material sometimes cannot be shod because the nails would split the material. Although attempts have been made to eliminate the metal shoe and/or nails, they have proved unacceptable for general use.
Plastic shoes have been proposed to eliminate the metal shoe. However, such plastic shoes have failed due to the ineffectiveness and reliability of the adhesive utilized to attach the plastic shoe to the hoof. Adhesive fails under normal circumstances including an exposure to water, shock, repeated flexing, extremes of temperature and other conditions during use. The methods and equipment employed in an attempt to produce a practically acceptable cure time have not been successful even with the inclusion of heat generating devices within the adhesive or heat conducting apparatus in contact with the adhesives.
A further method is suggested in U.S. Pat. No. 3,476,190 issued on Nov. 4, 1969 and entitled "Hoof-Covering and Method of Its Manufacture" which discloses casting a plastic shoe directly onto the hoof of an animal. Special treatment of the hoof is required by providing borings or openings in the hoof in which the plastic material flows for binding of the shoe to the hoof. Additionally, a mold must be fixed around the hoof of the animal rendering the molding process difficult and time consuming.
A need has thus arisen for a plastic shoe for a hoofed animal which can be cured in place with minimal cure time and which positively adheres to the hoof of the animal. The method of shoeing the hoofed animal must be simple and should be one that does not require significant hoof preparation prior to the shoeing operation.
DISCLOSURE OF THE INVENTION
In accordance with the present invention, an ultraviolet-cured shoe and method of shoeing a hoofed animal is provided which substantially eliminates the problems heretofore associated with shoeing procedures.
In accordance with the present invention, a method of shoeing a hoofed animal is provided. The method includes forming a mold having the general configuration of a shoe for the hoof. The mold is filled with a liquid plastic material, and the hoof of the animal is placed in the liquid filled mold. The liquid material is cured by exposing the material to ultraviolet light such that the material solidifies and is bonded to the hoof of the animal without any intervening adhesive material. The hoof with attached shoe is then removed from the mold.
In accordance with another aspect of the present invention, a shoe for attachment to the hoof of an animal is provided. The shoe comprises ultraviolet-cured acrylic material which is cured while the hoof is in contact with the acrylic material, such that the hoof and acrylic material are bonded when cured.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further advantages thereof, reference is now made to the following Detailed Description taken in conjunction with the accompanying Drawings, in which:
FIG. 1 is a diagrammatic illustration of the present casting mold and housing utilized in practicing the method of the present invention;
FIG. 2 is a sectional view taken generally along sectional lines 2--2 of FIG. 1 including the hoof of an animal placed within the present casting mold;
FIG. 3 is a sectional view taken generally along section lines 3--3 of FIG. 2;
FIG. 4 is a bottom plan view of a hoof and the shoe of the present invention;
FIG. 5 is a side elevational view of a hoof fitted with an additional embodiment of the shoe of the present invention including a resilient material;
FIG. 6 illustrates a side elevational view of a hoof fitted with an additional embodiment of the shoe of the present invention including cleats; and
FIG. 7 illustrates a casting mold and housing for forming the shoe illustrated in FIG. 6.
DETAILED DESCRIPTION
Referring to FIG. 1, a casting mold and housing utilized to practice the method of the present invention for casting a shoe in accordance with the present invention is illustrated, and is generally identified by the numeral 10. Although the present method and shoe will be discussed in connection with a shoe for a horse, it is understood that the present method and shoe can be utilized for any type of hoofed animal. Casting mold and housing 10 includes a casting mold, generally identified by the numeral 12 which is generally configured in the shape of a horseshoe. Casting mold 12 includes a bottom wall 14, sidewalls 16 and 18 and top walls 20 and 22. Casting mold 12 is formed of plexiglas or other similar material and is transparent.
Casting mold 12 is disposed within a housing, generally identified by the numeral 30 having a bottom wall 32 (FIG. 2), sidewalls 34 and 36 and end walls 38 and 40. Casting mold 12 is supported centrally within housing 30 and above bottom wall 32 utilizing supports 42, 44 and 46.
Disposed within housing 30 and between casting mold 12 and bottom wall 32 of housing 30 are ultraviolet bulbs 50 and 52. Bulbs 50 and 52 are mounted within sockets 54 and 56 respectively, which provide power received from a power supply and timer 60 for energizing bulbs 50 and 52. Power supply and timer 60 are connected to sockets 54 and 56 using wires 62.
The material utilized for molding the shoe of the present invention is supplied from a material supply source 64 via a delivery tube 66 to casting mold 12. The material enters casting mold 12 through an aperture 68. The material utilized for forming the shoe of the present invention includes a composite resin material that includes a monomer such as, for example, an acrylic monomer, that may be polymerized when exposed to ultraviolet light. Included in the composite mixture is an initiator for the polymerization such as a benzoin alkyl ether, where the alkyl group is commonly a methyl or ethyl group. Additionally, the present invention can be utilized with materials that are light cured utilizing visible light. Such materials include a composite resin mixture composed of monomers such as, for example, a urethane dimethacrylate and ethylene glycol dimethacrylate. Initiators sensitive to visible light such as a diketone, for example, camphoroquinone, in combination with an organic amine are included in the composite mixture. A light source such as a quartz halogen lamp may be filtered to eliminate all but visible light for use in the curing process. The acrylic material is injected into casting mold 12 in a liquid state and is subsequently cured through exposure to ultraviolet light. The curing time can be set utilizing power supply and timer 60.
In order to ensure that the entire casting mold 12 is exposed to ultraviolet light generated by bulbs 50 and 52, the interior surfaces of housing 30 are coated with a mirror-like surface. As more clearly shown in FIG. 2, the interior of bottom wall 32 of housing 30 includes a mirrored surface 70, the interior surfaces of sidewalls 34 and 36 include a mirrored surface 72 and 74, respectively, and the interior surfaces of end walls 38 and 40 include a mirrored surface 76 and 78, respectively.
Referring simultaneously to FIGS. 1, 2 and 3, the method of the present invention for shoeing a hoofed animal will now be described. FIGS. 2 and 3 illustrate the placement of a horse hoof 80 within housing 30 and above casting mold 12. The bottom of hoof 80 is placed along top walls 20 and 22 of casting mold 12 which supports the hoof above casting mold 12. The area of hoof 80 between sidewalls 16 and 18 comes in contact with the liquified acrylic material supplied by material supply source 64. The acrylic material penetrates into the porous interstities of hoof 80 and upon curing becomes bonded to hoof 80. The resulting shoe formed utilizing the method of the present invention is illustrated in FIG. 4.
FIG. 4 illustrates the bottom of hoof 80 (FIGS. 2 and 3) including a shoe 82 formed from ultraviolet-cured acrylic material and which is bonded to hoof 80. FIG. 4 also illustrates the sole 84 and frog 86 of hoof 80. Therefore it can be seen that the method of the present invention merely requires the placing of a hoof of an animal into casting mold 12, such that the hoof comes into contact with the acrylic material in the liquified state. Upon energization of bulbs 50 and 52, the acrylic material solidifies and becomes bonded to hoof 80. Minimal preparation of hoof 80 is required prior to its insertion into casting mold 12. The underside of hoof 80 may be smoothed prior to insertion into casting mold 12; however, any unevenness in this surface is compensated for by casting mold 12. The duration that ultraviolet bulbs 50 and 52 are energized is controlled by power supply and timer 60. The timer setting may be selected based upon the type of acrylic material utilized and is well known to one skilled in the art. Shoe 82 (FIG. 4) once cured, can only be removed by the mechanical cutting of the shoe-hoof combination from hoof 80.
Shoe 82 can be fabricated and sized utilizing a casting mold 12 of various sizes depending upon the hoof size and type of animal to be shoed. Additionally, the thickness of shoe 82 can be made relatively thin such that shoe 82 is lightweight, but extremely durable. Shoe 82 can be reinforced in the molding process of the present invention by combining fiberglass, carbon particles or the like with the acrylic material prior to curing. The addition of reinforcing material increases the tensile strength of shoe 82.
Referring now to FIG. 5, an additional embodiment of the present shoe 82 is illustrated. FIG. 5 illustrates hoof 80 having a shoe 90 which includes an elastomeric tread 92. Elastomeric tread 92 may be adhesively bonded to shoe 90 which is fabricated utilizing the procedure described above. Alternatively, the elastomeric tread 92 may be inserted in the bottom of casting mold 12 and the acrylic material placed directly on top of the elastomeric material within casting mold 12. In this manner, elastomeric material 92 becomes bonded to shoe 90 which in turn becomes bonded to hoof 80. A tread design may also be formed in bottom wall 14 of casting mold 12, such that a tread is molded into shoe 82 at the time of curing.
FIG. 6 illustrates a further embodiment of the present invention which illustrates hoof 80 including a shoe 94 having cleats 96. Cleats 96 may be molded from acrylic material comprising the same material of shoe 94 in a manner as described above.
Referring to FIG. 7 wherein like numerals are utilized for like and corresponding components previously described with respect to FIG. 1, a casting mold 100 for fabricating shoe 94 (FIG. 6) is illustrated. Casting mold 100 includes channels 102 formed within bottom wall 14 for forming cleats 96 (FIG. 6). Alternatively, metal spikes may be inserted within channels 102 which are then integrally molded into shoe 94 when the liquid acrylic is placed within casting mold 100.
An additional embodiment of the present invention includes the application of the acrylic material directly to the hoof 80 without the use of mold 12. The acrylic material would be rendered thicker and applied with a putty knife to hoof 80 prior to polymerization. The hoof 80 and acrylic material would then be exposed to the light source for curing.
Therefore it can be seen that the present invention including a shoe and a method of shoeing a hoofed animal which provides for a relatively thin shoe that is easily attached to the hoof of an animal without the use of mechanical fasteners or adhesives. The shoe of the present invention is fabricated directly onto the hoof of an animal such that the shoe becomes an integral part of the hoof. The underside of the hoof may include various coverings including resilient material in the form of various tread designs, cleats or smooth surfaces depending upon the type of surface the animal will be traveling upon.
Whereas the present invention has been described with respect to specific embodiments thereof, it will be understood that various changes and modifications will be suggested to one skilled in the art and it is intended to encompass such changes and modifications as fall within the scope of the appended claims.
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A method of shoeing a hoofed animal is provided and includes the step of forming a mold (12) having a general configuration of a shoe for the hoof (80). The mold (12) is filled with a liquid acrylic material (64). The hoof (80) of the animal is placed within the mold (12). The acrylic material is cured utilizing ultraviolet light (50, 52), such that the liqid acrylic material solidifies and is integrally joined to the hoof (80) without any intervening adhesive or mechanical attachment. The hoof (80) is then removed from the mold (12).
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This application is a §371 of International PCT Application PCT/FR2006/051049, filed Oct. 18, 2006.
BACKGROUND
1. Field of the Invention
The present invention relates to a pressurized-gas filling and distribution head and to a tank equipped with such a head.
2. Related Art
The supply of gas to gas-consuming devices, for example fuel cells, presents numerous problems. In particular, it is important to simplify and secure the supply by, in particular, working along the principle of exchanging an empty tank for a full tank.
This problem is all the more sensitive because the current trend is to increase service pressures with a view to offering a better ratio between the mass of stored gas and the overall mass of the tank, combined with smallness of size.
In addition, such systems are becoming more widespread, involving use of the gas by non-specialists (professionals such as nurses, laboratory workers, for example, or by the general public such as DIY enthusiasts, motorists, etc.).
One objective of the systems for storing fluid and of the devices for filling them and/or for tapping fluid off from them, is to make the handling operations needed to exchange an empty tank for a full tank easier. The storage systems have in addition implicitly to provide a level of safety that allows the handling operations to be performed by non-specialists while at the same time improving the safety and productivity in tank processing centers.
It is known practice for gas to be stored in liquid form. In known solutions (CO 2 for example), this is performed quite naturally and does not require the use of special facilities. In most cases (for example that of hydrogen), however, it is necessary to maintain temperature conditions such that the use of special facilities is compulsory (thermal insulation, control of boiling or “boil-off”). This operation makes the solution for storing liquid somewhat irrelevant because it is far too complicated and ill suited to the idea of exchanging an empty one for a full one.
Solutions for storing gas in gaseous form conventionally include cylinders equipped with a simple valve which, if open, places the user in direct contact with the storage pressure. It is therefore necessary, in order to use the gas, to connect up equipment (pressure regulators, flow meters, etc.) and this entails tooling and tricky operations. These operations become all the more risky when the user is not a professional (with the risk of leaks, forcible expulsion of parts, etc.).
Lightweight small-sized gas refills are known, these proposing a solution which is to provide the canister with a valve that has no actuating member, but the disadvantage with these is that the gas is delivered at the storage pressure.
In order to guard against the risks associated with the high pressure, canisters or cylinders may be equipped with a regulating valve which, as far as the user is concerned, allows him access only to a reduced pressure. This solution has the disadvantage of creating a protruding part on the cylinder. This protruding part therefore needs to be protected. This protection is generally formed by a bonnet. On the whole, the weight and size are increased and incorporating the cylinder into the application that requires the gas may lack simplicity.
Furthermore, most reserves of gas delivered to customers need to be mobile. In an extreme case, the self-contained gas source may have to be deployed and to accompany the gas-consuming application, for example to supply a fuel cell at an isolated site or to accompany fire fighters attending an emergency.
Each customer or customer family has its own specific requirements that have to be met as best possible. The consequence of this is to make the industrial organization more complicated because it is necessary to manage a wide variety of products (fluid/tank pairing and fluid delivery conditions).
One problem that needs to be solved is, on the one hand, to offer the user and/or the operator means that make it easier for him to transport and to handle a reserve of gas and, on the other hand, to offer the user means that will allow him to customize the design of a reserve of gas in order to meet the requirements of his particular application and to allow the operator flexibility that will allow him to manage the variety of products needed to meet the requirements of his customers.
Of the solutions for storing gas in gaseous form, cylinders equipped with a simple valve are favored by the operators and by industry for questions of managing the population of cylinders. If open, the simple valve places the user directly in contact with the fluid at its storage pressure. It is therefore necessary, in order to use the gas, to connect up hardware (pressure regulator, flow meter, etc.) which demands tooling and tricky operations, accompanied by the risks involved in this type of operation when the user is not a professional. This solution is therefore not favored by the end-user.
Better favored by the end-user is the regulating valve attached to the cylinder delivering the fluid as the pressure needed by the application. However, use of such a regulating valve places significant constraints upon industry particularly in terms of managing the population of cylinders, maintenance, interface with the filling equipment, etc.
In known designs for storing gas under pressure, the valve incorporates a regulating device which is positioned inside the volume of the cylinder (cf. for example EP-A-1316755). These known devices make it possible in part to limit the volume of the valve but require the user to perform numerous handling and coupling operations in order to fill and tap off from the cylinder.
Thus, none of the aforementioned existing solutions simultaneously considers these specific requirements of industry and those of the customer.
it is one object of the present invention to alleviate all or some of the disadvantages recalled hereinabove of the prior art.
SUMMARY OF THE INVENTION
To this end, the invention relates to a gas filling distribution head intended to be placed in the orifice of a pressurized-gas storage tank, the head comprising a mounting portion intended to be housed in the orifice of the tank and a pressure-regulating portion housing a pre-regulating device, the pre-regulating device being positioned relative to the mounting portion such that it is housed at least partially inside the tank when the head is in the mounted position, the head comprising a filling circuit extending between a first end provided with a filling orifice and a second end intended to communicate with the inside of the tank, a tapping-off circuit ( 22 , 23 , 283 , 32 , 6 ) extending between a first end intended to communicate with the inside of the tank and a second end provided with a tapping-off orifice.
BRIEF DESCRIPTION OF THE FIGURES
Other particulars and advantages will become apparent from reading the below description which is given with reference to the figures in which:
FIGS. 1 and 2 depict external views in isometric projection of one exemplary embodiment of a tank according to the invention, respectively with and without a casing covering the external surface of the tank 1 .
FIG. 3 is a view in longitudinal section on a larger scale of the upper part of the tank of FIG. 2 .
FIG. 4 is an external view in isometric projection of one exemplary embodiment of a filling connector, particularly for a tank according to FIGS. 1 and 2 .
FIG. 5 is a view in longitudinal section of the filling connector of FIG. 4 .
FIG. 6 is a view in longitudinal section of the filling connector of FIG. 4 connected to the tank of FIG. 2 .
FIGS. 7 and 8 are external views in isometric projection of an exemplary embodiment of a head for delivering fluid according to the invention.
FIG. 9 is an external view in isometric projection of the head delivering fluid of FIGS. 7 and 8 , equipped with an outlet coupling.
FIG. 10 is a view in longitudinal section of the delivery head of FIGS. 7 and 8 , equipped with its outlet coupling.
FIG. 11 is a view in longitudinal section of the delivery head of FIG. 10 equipped with its outlet coupling and mounted on a tank according to FIG. 2 .
FIG. 12 is a view in longitudinal section of the gas delivery head mounted on the tank.
FIG. 13 shows a section of the casing used to protect the tank.
FIG. 14 depicts a schematic and partial view from above of the internal mechanism of the delivery head of FIGS. 7 and 8 .
FIG. 15 shows an embodiment that includes a bypass portion ( 375 ).
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, the filling orifice coincides with the tapping-off orifice.
Furthermore, the invention may have one or more of the following features:
the head comprises an isolating member such as an isolating valve, the isolating member is positioned relative to the mounting portion so that it is at least partially housed inside the volume of the tank when the head is mounted in position in the orifice of a tank, the isolating member is formed in such a way that it can be opened and/or closed by an actuating element external to the head, the isolating member is housed at least partially inside the volume of the head and is accessible to an actuating element external to the head via an access orifice formed in the head, the access orifice providing access to the isolating member coincides with the orifice intended both for filling and for tapping-off, the isolating member is positioned downstream of the pre-regulating device on the tapping-off circuit ( 22 , 23 , 283 , 32 , 6 ) between the first end and the second end of the tapping-off circuit ( 22 , 23 , 283 , 32 , 6 ), the isolating member is positioned downstream of the pre-regulating device in a path from the inside of the tank to the outside of the tank, the isolating member and the pre-regulating device are positioned in one and the same duct along which fluid flows between the inside and the outside of the tank, such that the filling and the emptying of the tank are performed more or less along one and the same axis and via this same duct, the tank comprises a connection interface intended to collaborate removably with a device for controlling the filling of the tank and/or the delivery of fluid from the tank, the connection interface comprises an internal portion housed inside the body of the filling head and in that the isolating member is positioned at least partially within the portion housed inside the internal portion of the interface, the isolating member comprises a body capable of moving relative to the head and able to collaborate for the purposes of being open or for the purposes of being closed with a seat, the isolating member comprising a free downstream end capable of being pushed in order to open or close it, the isolating member is capable of translational movement, the pre-regulating device comprises a movable shutter member capable of collaborating for the purposes of being open or for the purposes of being closed with a seat, a first return means urging the valve element toward its closed position against the seat, the valve element being urged into its open position by a free-regulating piston urged by a second return means.
Another object of the invention is to propose a tank for pressurized fluid, comprising a casing delimiting a storage volume and provided with an orifice for communicating with the inside of the tank, the tank comprising a filling and distribution head positioned at the orifice, according to any one of the features mentioned hereinabove or hereinafter.
Furthermore, the invention may include one or more of the following features:
the tank comprises a casing delimiting a storage volume and provided with an orifice for communicating with the inside of the tank, the tank comprising a filling and distribution head positioned at the orifice, characterized in that the head is a head according to any one of the preceding features, and in that the isolating member and the pre-regulating device are positioned in one and the same duct along which fluid flows between the inside and the outside of the tank, the filling and the emptying of the tank being performed more or less via one and the same orifice and along one and the same axis that more or less coincides with the axis of the tank, the filling ( 6 , 8 , 32 , 283 , 23 , 22 ) and tapping-off circuits ( 22 , 23 , 283 , 32 , 6 ) have at least one portion in common, the pre-regulating device comprises a two-way valve mechanism selectively allowing the pressure-regulated gas to leave the tank or high-pressure gas to enter the tank depending on the pressure differential across the two-way valve mechanism, the pre-regulating device comprises a pre-regulating valve urged toward a seat and subjected to the opposing force of a pre-regulating piston, the pre-regulating piston comprises an internal duct connected, on the one hand, to the isolating member and, on the other hand, to a low-pressure chamber situated at the junction between the seat and the said pre-regulating piston, the filling circuit ( 6 , 8 , 32 , 283 , 23 , 22 ) comprises a bypass portion ( 375 ) that bypasses the pre-regulating device to prevent filling gas from passing through the pre-regulating device during filling.
According to other possible features, the invention proposes a device for controlling the filling of and/or the tapping-off from the tank comprising a body provided with a connection end provided with attachment means intended to collaborate with complementary attachment means belonging in particular to a connection interface of a tank for pressurized fluid, a valve-opening member that can move relative to the body, actuating means capable selectively of moving the valve opening member between a rest position and a work position, that alleviates all or some of the above disadvantages.
To this end, the device for controlling the filling of and/or the tapping-off from the tank is essentially characterized in that it comprises a body provided with a connection end provided with attachment means which are intended to collaborate with complementary attachment means belonging in particular to a connection interface of a tank for a pressurized fluid, a valve-opening member capable of moving relative to the body, actuating means capable selectively of moving the valve-opening member between a rest position and a work position, characterized in that, in the work position, one end of the opening member projects out of the body beyond the connection end so as to allow the valve-opening member to dip down inside a volume of a complementary connection interface.
Furthermore, the invention may have one or more of the following features:
the complementary attachment means comprise projecting pins and/or mating housings so as to form a fastening of the bayonet type, the device comprises removable means of locking the attachment means, the attachment means comprise housings substantially in the shape of cranked slots having an open first end intended to allow a pin to enter and exit the housing and a second end that forms a closed end designed to accommodate the pin in the attached position, the removable means of locking comprising at least one end forming an end stop in at least one housing, the end stop being able to move between an immobilizing first position between the two ends of the housing, and a retracted second position allowing travel between the two ends of the housing, the device comprises return means that urge the end stop into its immobilizing position, the end stop being capable of being moved into its retracted position either under the pressure of a pin inserted from the first end of the housing or by pulling on the locking means using a region for grasping, the device comprises a fluid inlet orifice, a first safety valve, and a fluid pressure regulating member, the first safety valve and the pressure regulating member being connected in parallel to the inlet orifice via a duct, the outlet of the pressure regulating member is connected to a second safety valve and to a fluid outlet orifice leading to the outside of the device, the second safety valve and the fluid outlet orifice are connected in parallel to the outlet of the pressure regulating member via respective pipes, the isolating member comprises a body able to move relative to the head and capable of collaborating for the purposes of being open or for the purposes of being closed with a seat, the isolating member comprising a free downstream end capable of being pushed in order to open or close it, the isolating member is capable of translational movement, the pre-regulating device comprises a moving valve element capable of collaborating for the purposes of being open or for the purposes of being closed with a seat, a first return means urging the valve element toward its closed position against the seat, the valve element being urged toward its open position by a pre-regulating piston urged by a second return means, the tank comprises a so-called “low pressure” chamber downstream of the pre-regulating device, the isolating member and the pre-regulating valve are able to move more or less along the same axis, the connection interface comprises an external portion projecting out of the tank and provided with attachment means intended to collaborate with complementary attachment means belonging to a device for controlling the filling and/or the tapping-off, the external portion comprises a concave accommodating region intended to accommodate and to guide a tubular end of a control device, the filling head comprises a tell-tale device indicating the fill status of the tank and comprising at least one duct in communication with the inside of the tank, a moving indicator member subjected, on the one hand, to the pressure inside the tank via the duct and subjected, on the other hand, to the influence of a return means, the position of the moving indicator member being correlated with the pressure inside the tank, the filling head comprises a safety discharge device comprising a port, the port comprising a first end connected to the outside of the tank and blocked off by a closure means that can melt under the action of heat and/or when a determined pressure is exceeded, and a second end connected to the inside of the tank, the tank comprises removable and/or deformable protective means forming a removable screen between the outside of the tank and the isolating member, the tank comprises an axis of almost symmetry that is longitudinal, and in that the attachment means of the external portion of the interface are directed or positioned along the longitudinal axis of symmetry, the low-pressure chamber is connected to the internal portion of the interface via a passage that passes through the pre-regulating piston, the additional attachment means are formed respectively on the end walls and on the external portion of the connection interface.
Another object of the invention is to propose an assembly comprising a tank and a device for controlling the filling of the tank and/or the tapping-off of fluid from the tank, according to any one of the preceding or following features.
Other particulars and advantages will become apparent from reading the following description which is given with reference to the figures in which:
FIG. 1 depicts an oblong tank body 1 having a cylindrical main part 10 and two substantially dome-shaped ends, one lower 11 and one upper 12 . The rounded upper end 12 has a filling and distributing head 2 . As depicted, the filling and distribution head 2 in particular comprises a connection interface 3 , a tell-tale indicating the fill level 4 , an anti-knock shield and a central orifice 6 providing access to the inside of the tank 1 .
FIG. 2 shows an alternative form of the gas storage assembly (tank 1 ) according to the same embodiment, with an optional casing 100 more or less entirely covering the external surface of the tank 1 . The casing 100 (or jacket) is designed to protect the tank 1 against any knocks or droppage.
The oblong casing 100 of dimensions tailored to the tank 1 has its rounded lower end 111 made to correspond to the lower end 11 of the tank 1 . The cylindrical central part of the casing 100 hugs the cylindrical part 10 of the tank 1 . The rounded upper end 112 of the casing for its part covers the upper end 12 of the tank 1 .
Slots 102 on the periphery of the upper end 112 of the casing allow the casing 100 to be slipped over the tank 1 .
At the upper end of the casing in particular, a collar 103 fitted with a closure 104 (of the touch-and-close type or press-stud type or any other equivalent means) may be provided to hold the casing 100 in place on the tank 1 .
The casing 100 on its periphery has ergonomic imprints 101 making the whole easy to hold. The casing 100 is preferably made of thermoformed high-density foam but any other material such as neoprene, an elastomeric material, etc. may be considered.
Reference is now made to FIG. 3 in which the tank 1 comprises a sealed internal casing 13 (or “liner”), for example made of aluminum alloy or the like, intended to contain the fluid and particularly gas under pressure. The casing 13 is reinforced on its external surface by a winding of carbon fiber filaments 14 bonded together with epoxy resin or any other equivalent means.
An oblong filling head 2 is positioned in the tank 1 , at the orifice of the tank 1 , inside the casing inner 13 .
The body 20 of the filling and distribution head 2 is mechanically connected to the casing 13 by virtue, for example, of a screw thread 21 collaborating with a tapped thread formed on the casing 13 . An annular seal 7 is positioned in a groove formed in the casing 13 . The groove lies at the upper end of the casing 13 and is enclosed by the body 20 of the filling and distribution head 2 so as to provide sealing between the body 20 and the inside of the tank 1 .
The filling and distribution head 2 in its lower part comprises a pre-regulating cartridge 22 which is screwed into its body 20 by virtue of a screw thread/tapped thread system 221 .
Downstream of the pre-regulating cartridge 22 (toward the top of the cartridge 22 ), the filling and distribution head 2 comprises a low-pressure chamber 23 . Sealing between the inside of the tank 1 and the low-pressure chamber 23 is afforded by the combination 222 of an O-ring and of anti-extrusion rings positioned between the cartridge 22 and the body 20 of the head 2 .
The pre-regulating cartridge 22 comprises, working from upstream to downstream (that is to say from its lower part toward its upper part in FIG. 3 ), a filter 24 , a threaded ring 25 and a pre-regulating valve 26 . The filter 24 is held in the cartridge 22 by an elastic ring 241 housed in a groove 223 formed in the body of the cartridge 22 .
The pre-regulating valve 26 is subjected to the action of a spring 261 moving it toward a seat 27 held in the cartridge 22 under the action of the threaded seat holder 271 . The valve 26 is subjected to the force of the valve spring 261 and to the force of the pressurized gas.
The upper end of the valve 26 is equipped with a stem 261 extending upward and the end of which is in contact with a pre-regulating piston 28 . The piston 28 for its part is urged toward the valve 26 by a spring 281 . Because of the force of the spring 281 and the action of the gas on the cross section 282 of the piston 28 , the valve 26 acts as a pressure regulator.
During phases in which gas is tapped off from the tank 1 , the gas contained in the tank 1 under high pressure passes, while its pressure is being reduced, through the pre-regulating cartridge 22 toward the low-pressure chamber 23 .
The pressure-regulated gas then passes through the piston 28 via a drilling 283 formed in the body of the piston, to emerge in a chamber 32 situated in the body of a connection interface 3 . The connection interface 3 is mounted at the upper end of the head 2 .
The chamber 32 comprises an isolating valve 8 which is sealed with respect to the inside of the tank by a seal that seals against the body 30 of the connection interface 3 .
The default setting of the isolating valve 8 is closed. The isolating valve 8 is, for example, a valve of a conventional type, such as a valve comprising a fixed tubular body and a rod capable of moving inside the body to make the valve allow the passage of fluid or prevent the passage of fluid depending on the position of the rod.
The valve 8 can be actuated by a valve driver external to the head, that is to say belonging to an external actuating means that can be attached to the head 2 . The valve driver system described in greater detail hereinafter may belong to a system that receives the storage assembly or to a gas distribution head or to a cylinder filling connector.
The upper end of the connection interface 3 projects out from the filling and distribution head 2 of the tank 1 .
This outer part of the connection interface 3 comprises four projecting pins 35 (bayonets) positioned 90° apart to allow for attachment of a receiving system belonging to a storage assembly or to a gas distribution head or to a filling connector. Of course, this exemplary embodiment is nonlimiting, particularly given the considerable number of conceivable combinations of number, shape and position of pins and corresponding polarizing (that is to say geometrical identity) options available. In addition, other attachment means that perform the same function are conceivable, including screw/nut connections, a latch lock lever, a retractable catch, etc.
The outer part of the connection interface 3 comprises a tubular housing forming an accommodating region 36 the purpose of which is to accept and to guide a mating tubular end of a receiving system or of a gas distribution head or of a filling connector as described hereinafter.
To this end, the mating tubular end of the control member intended to be connected to the tank 1 comprises an O-ring seal and possibly an anti-extrusion ring to ensure the continuity of the seal between the control device and the tank 1 .
The external part of the connection interface 3 preferably comprises a removable protective membrane 33 intended to avoid the ingress of particles or dirt into the accommodating region 36 and that might cause the system to malfunction. The membrane 33 is, for example, made of precut shape-memory polymer. The membrane is, for example, held at the inlet of the accommodating region 36 by a plastic anti-impact shield 34 . Of course, any other form of embodiment for protecting the inlet of the accommodating region is conceivable, for example a film that has to be punctured, or a sticker that has to be removed, or the like.
Thus, when the tubular end of a control device (receiving system or gas distribution head or a filling connector) is introduced into the receiving region 36 , the precut membrane 33 will move aside against the surface 37 of the connection interface 3 . For example, the shape-memory protective membrane 33 is precut into four “petal-shaped” lobes. As it enters, the male tubular end of a control device will push the four lobes back against the surface 37 of the connection interface 3 . The lobes will automatically return to their initial position ( FIG. 3 ) when this same tubular end is extracted.
The tank 1 comprises a tell-tale 4 comprising a body 41 screwed into the body 20 of the device of the filling and distribution head 2 by means of a screw thread system 47 . Sealing between the tell-tale and the filling head 2 is provided by means of a stressed metal seal 42 . A moving spindle 43 is guided in the body 41 of the tell-tale 4 . Sealing between the spindle 43 and the body 41 is afforded by the combination 45 of an O-ring seal and of an anti-extrusion ring.
The spindle 43 of the tell-tale 4 is subjected to the opposing forces of a return spring 44 and of the pressure of the gas contained in the tank 1 carried through the tell-tale 4 via a screw thread 21 and drillings 46 .
When the action of the gas pressure exceeds the force of the return spring 44 , the end of the spindle 43 emerges into a viewing chamber 48 formed in the body 41 of the tell-tale 4 . Thus, the tell-tale indicates that the gas store is full (the pressure of the gas contained in the tank 1 is optimal). If not, the end of the spindle 43 does not emerge into a viewing chamber 48 , this indicates that the gas store is not full (the pressure of the gas contained in the tank 1 is below the optimum pressure).
A safety device (of the type that melts under the action of heat and/or discharge valve, rupture disk, etc. type) may be fitted to the tank 1 via a port 9 formed in the body 20 of the filling and distribution head 2 . This safety device may be fed with the gas contained in the tank 1 via a cut 92 machined in the screw thread 21 and via drillings 91 .
FIGS. 4 and 5 illustrate a filling connector that has a body 300 , a connection interface 303 and a control lever 302 . The body 300 is connected to the end of a filling hose 317 by a screw thread 318 (for example a tapered screw thread sealed with PTFE (polytetrafluoro-ethylene) tape).
The filling hose 317 supplies the filling circuit ( 317 , 319 , 8 , 32 , 283 , 23 , 22 ) via a filling pipe 319 . The filling pipe 319 is dirt free thanks to a filter 315 held in place in the body 300 under the effect of an elastic ring 316 held captive in a groove formed in this same body.
A manual control lever 302 that can rotate about a spindle 330 is capable of transmitting a translational movement to a valve driver 310 via a cam 320 which rubs against a wear plate 312 . Of course, the pivoting manual lever 302 may be replaced by any analogous system, for example an automatic control.
There is a spring 311 in the body 300 in order constantly to keep the end 321 of the valve driver 310 held against the wear plate 312 in contact with the cam 320 .
To ensure the continuity of the cross section for the passage of gas through the filling pipe 319 , the exterior surface 322 of the valve driver 310 is of hexagonal cross section while the cylindrical surface 323 has two flats. The dynamic sealing of the valve driver 310 with respect to the body 300 is provided by a combination 313 of an O-ring seal and of an anti-extrusion ring, these being held in their housing by a gland 314 .
As depicted more specifically in FIG. 6 , the connection interface 303 of the filling connector collaborates with the connection interface 3 of the tank 1 .
More specifically, the projecting pins 35 (bayonets) of the connection interface 3 of the tank 1 enter channels or millings 304 in the connection interface 303 of the filling connector. The pins 35 position themselves in the respective housings 306 at the closed ends of the cranked channels 304 .
As they enter the channels 304 , the pins push and temporarily retract a safety catch 305 . When the pins are in their housing 306 , the catch 305 is returned to its initial locking position under the action of a spring 309 . In this way, the catch 305 traps two diametrically opposed pins 35 in their respective housings 306 b . In this position, the filling connector is locked onto the tank 1 .
The filling connector has a tubular end 308 which becomes housed in the accommodating region 36 of the connection interface 3 of the tank 1 . Sealing between these two surfaces (the tubular end 308 and the accommodation region 36 ) is provided by the combination 307 of a seal and of an anti-extrusion ring.
To open the valve 8 of the tank 1 , the lever 302 is actuated in such a way that the cam 320 via the wear plate 302 acts on the valve driver 310 transmitting to it a translational movement that is passed on to the stem 82 of the valve 8 .
The valve driver 310 therefore projects relative to the tubular end 308 and relative to the filling connection so as to allow it to dip down into the head 2 housed in the tank 1 in order to actuate the valve 8 .
The cam 320 comprises a flat surface 325 that allows this position to remain stable. The valve closure 8 has to be performed manually by performing the reverse operation on the control lever 302 .
The filling fluid can then be injected into the filling connector via the pipe 319 .
The filling fluid passes in succession through the open valve 8 , the chamber 32 and the drilling 283 of the pre-regulating piston 28 . The surface 282 of the piston 28 is therefore subjected to the pressure of the gas which is stronger than the force of the spring 281 . This gas pressure moves the piston which thus moves free of the end of the stem 261 of the pre-regulating valve 26 .
The pre-regulating valve 26 is therefore opened by the action of the pressure of the gas passing through the pre-regulating cartridge 22 in the opposite direction in order to return to the tank 1 . As an alternative, the filling circuit may short circuit the pre-regulating system.
At the end of the filling operation, once the high pressure in the filling pipe has been dumped, the pre-regulator can be reactivated. The valve 8 is closed again by action on the control lever 302 of the filling connector.
Once all of the gas contained in the entire filling circuit ( 6 , 8 , 32 , 283 , 23 , 22 ) (the entire volume downstream of the valve 8 ) has been dumped, the filling connector can be uncoupled through a process that is the reverse of the one described hereinabove.
To uncouple the filling connector, the control 301 of the catch 305 has to be pulled manually against the force of the spring 309 in order to free the protruding pins 35 (bayonets) from their housings 306 and 306 b following the path of the cranked milled slots 304 . The tubular end 308 comes free of the accommodating region 36 , the precut membrane 33 returns to its original position preventing particles or dirt from entering.
FIGS. 7 and 8 illustrate a removable gas delivery head 150 comprising a control to open up the flow rate of gas 250 , an annular knob to shut off the flow rate of gas 350 , access 450 to the outlet coupling naturally closed off by a shutter to prevent contamination and a connecting interface 516 . The gas delivery head 150 also comprises medium-pressure and low-pressure discharge valve discharge louvers 115 and a location 65 for information intended for the user and which may be in the form of a digital display offering customized autonomy information (or pressure gage or any other known means).
FIG. 9 illustrates the gas delivery head 150 according to the same embodiment, equipped with an outlet coupling 75 the orifice 70 of which is connected to a hose (not depicted) supplying the application.
Advantageously, the head 150 is shaped in such a way that
if the outlet coupling 75 is not connected, it is impossible to lock the control to open the flow rate of gas 250 , if the outlet coupling 75 is connected to the removable gas delivery head 150 , it is possible to lock the control to open up the flow rate of gas 250 , the shutting-off of the flow rate of gas being controlled by action on the annular knob 350 and a control 415 for unlocking the outlet coupling 75 is accessible, if the outlet coupling 75 is suddenly disconnected while the control to open up the gas is active, the latter control is immediately disconnected.
FIG. 10 depicts details of the gas delivery head according to the same embodiment. The case that protects the delivery head 150 is made up of two half-shells 511 joined together by clips and two screws 135 . The delivery head 150 contains, on the one hand, a body 512 comprising the various active gas-delivery components and, on the other hand, the user interface controls. In particular, the delivery head 150 comprises a control to open up the flow rate of gas 250 , an annular knob to close off the flow rate of gas 350 , and an access 450 providing access to the outlet coupling 75 .
The lower part of the body 512 ends in a tubular end 514 with an O-ring seal 515 and a component 516 displaying symmetry of revolution which in this instance has four millings 161 positioned 90° apart. Of course, the invention is not restricted to this configuration and any other combination of number and positions of millings may be considered.
The lower part of the body 512 forms a connection interface that can collaborate with and be attached to the coupling interface of a tank 1 as described hereinabove and illustrated in FIG. 11 . In FIG. 11 , the gas delivery head 150 mates with and extends the protective jacket 100 of the tank 1 .
Passing through the body 512 is a valve driver 17 which is dynamically sealed with respect to said body 512 by an O-ring seal 172 .
The upper end of the valve driver 17 comes into contact with the spindle of the control to open up the flow rate of gas 250 when the latter is pressed and locked.
The spindle of the control to open up the flow rate of gas 250 may thus transmit a translational movement to the valve driver 17 which itself passes this translational movement on to the valve stem 8 of the tank 1 described hereinabove. The valve driver 17 therefore projects beyond the lower part of the body 512 to enter the head 2 of the tank 1 , so as to open up the flow rate of gas.
The fluid stored in the tank 1 then enters the body 512 by the annular orifice 121 . The annular orifice 121 simultaneously, via the transverse drilling 122 , supplies a medium-pressure safety valve 123 and a pressure-regulating stage 58 .
The medium-pressure safety valve 123 comprises a discharge valve 124 the opening of which is determined by the calibration force of a spring 125 . The medium-pressure safety valve 123 is formed in such a way as to allow surplus pressure to be discharged through the louvers 115 formed in the two half-shells 511 .
The pressure-regulating stage 58 comprises a mechanism enclosed in a cartridge 88 which is screwed into the body 512 and sealed with respect to the latter by an O-ring seal 881 .
Gas enters the pressure-regulating stage 58 by passing through a filter 881 held by an elastic ring 582 held captive in a groove formed in the body 512 . The entry of gas into the pressure-regulating stage 58 is also via the passage around a spacer piece 83 that allows the fluid to arrive radially and uniformly at a pressure-regulating valve 84 .
As a result of the force of a valve spring 85 and of the action of the gas, the pressure-regulating valve 84 collaborates with a seat 86 . The seat 86 is held in place in the cartridge 88 under the action of a threaded seat holder.
The valve 84 is equipped with a stem 841 extending upward and the end of which is in contact with a metal bellows 89 . The metal bellows 89 is held in a sealed manner inside the body 12 under the combined action of a screw-on cap 891 and an O-ring seal 893 . The valve 84 is subjected to the force of a pressure-regulating spring 891 preloaded by a pressure-regulating screw 892 and the force of the gas on the cross section of the metal bellows 89 . Thus, the valve 84 regulates pressure.
Advantageously, the pressure-regulating screw 892 is adjustable so as to allow the user to vary the spring force and therefore the pressure regulation.
As depicted schematically in FIG. 14 , a drilling 200 , 355 , formed in the body 12 allows the pressure-regulated gas to pass from inside the metal bellows 89 to an outlet connection 95 ( FIG. 10 ).
At the same time, the drilling 200 , 211 formed in the body 12 allows the pressure-regulated gas to pass between the metal bellows 89 and a low-pressure discharge valve 201 (of the same type as the valve 123 described hereinabove).
The set points at which the discharge valves 123 and 201 open are chosen to suit the requirements of the application. The medium-pressure valve 123 is, for example, rated to discharge pressures in excess of 20 bar to the outside while the low-pressure discharge valve 201 is rated to discharge pressures in excess of 400 mbar to the outside.
The outlet connection 95 is screwed in a sealed fashion into the body 12 . This male outlet connection comprises a skirt 591 containing a shut-off device 592 which is closed by default and sealed against the said skirt 591 by the action of a spring 93 .
The shut-off device 592 prevents, on the one hand, the ingress of particles and dirt into the gas circuit when the outlet coupling 75 is not connected. In addition, the shut-off device 592 prevents any flow of fluid to the atmosphere in the event either of forced action on the opening control 250 while the outlet coupling 75 is not connected, or if the outlet coupling 75 becomes disconnected.
The outlet coupling 75 is made up of a body 71 containing a shut-off member 72 . The shut-off member 72 is subjected to the action of a spring 73 so that by default it is closed and sealed against said body 71 .
This shut-off member 72 on the one hand prevents the ingress of particles and dirt into the gas circuit when the outlet coupling 75 is not connected and on the other hand prevents the fluid contained in the supply pipe of the application from being dumped to the atmosphere if said outlet coupling 75 becomes disconnected. When the outlet valve 75 is connected to the male outlet connection 95 , on the one hand, the circuit becomes sealed under the action of an O-ring seal and, on the other hand, the circuit is opened by virtue of the mutual actions of the two shut-off members 72 and 592 .
The tank 1 comprises a pre-regulating device incorporated into its neck and, possibly, also incorporated into this same neck, an isolating member. Thus, the very high pressure (the storage pressure) is isolated and the user is protected. The projecting part of the tank contains no high pressure and need not be protected by a bonnet.
The unique inlet/outlet connection interface of this tank is of the quick-coupling type and requires no tooling. Advantageously, this tank 1 can be refilled only with a special-purpose filling connection that collaborates with the unique connection interface of the tank. Access to this interface is found along the main axis of the tank 1 , making it possible to conceive of automated filling solutions.
The idea of the automatic dispensing of these canisters, cylinders or tanks may be conceived of for applications both professional and for the general public. Delivery of gas entails either inserting the cylinder, canister or tank into a receiving housing equipped with means of opening the valve and of regulating the gas to suit the application, or connecting a special-purpose head provided with these very means.
Making the connections on the axis of the tank simplifies the handling operations and implicitly improves safety. The interfacing between cylinders, canisters or tanks and the accommodating system or special head is performed in such a way that the connection can be made only if the gas being delivered is actually that expected by the application.
FIG. 12 depicts the gas delivery head 150 mounted on its gas source (tank 1 ) as described hereinabove. The tank 1 is guided and enclosed in another type of protective jacket 100 with an attached bottom 133 . The protective jacket 100 is hollow and on its interior surface has at least one region comprising longitudinal flexible strips 328 (cf. FIG. 13 ).
The strips 328 secured to the internal wall of the jacket 100 both immobilize the tank in said jacket 100 and compensate for geometric variations thereof resulting in particular from its internal pressure and its manufacturing tolerances. Furthermore, the strips 328 are able to absorb the energy generated if the tank thus clad is dropped or knocked.
The attached bottom 133 of the casing 100 has a helical screw thread 331 intended to be screwed into a helical cut 321 in the body of the jacket 100 . The removable bottom 133 thus makes it easier to mount and secure the tank 1 in said protective jacket 100 . In addition, the removable bottom 133 means that customary maintenance operations performed on the tank 1 will not be impeded.
The upper part of the jacket 100 may comprise a female recess 522 to position and rotationally index the tank 1 with respect to said jacket 100 . In this way, it is possible for example to make the tell-tale that indicates the capacity and the safety members (the discharge valve, the safety feature that melts under the action of heat, the rupture disk, etc.) of said tank 1 tally with corresponding openings in its protective jacket 100 .
The invention can be applied to any uses of fluid that demand a great flexibility of use, a good compromise between lightness of weight, size and capacity (autonomy). For example, the gaseous hydrogen for a portable or mobile fuel cell, medical gases, and gases for analysis and laboratory use.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.
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The invention relates to a gas filling and distribution head ( 2 ) which is intended to be disposed in a hole in a pressurized gas storage tank. The inventive head ( 2 ) includes a mounting segment ( 21 ) which is intended to be housed in the hole in the tank and an expansion segment which houses a pre-expansion device ( 22 ), said pre-expansion device ( 22 ) being arranged in relation to the mounting segment ( 21 ) such as to be housed at least partially inside the tank when the head is in the mounted position. The head ( 2 ) also includes: a filling circuit which extends between a first end which is equipped with a filling hole ( 6 ) and a second end which is intended to communicate with the interior of the tank, and an extraction circuit which extends between a first end which is intended to communicate with the interior of the tank and a second end which is equipped with an extraction hole. The invention is characterized in that the filling hole ( 6 ) is aligned with the extraction hole.
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FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] This invention was made with government support under Contract No. DMI-0318901 awarded by the National Science Foundation. The United States Government has certain limited rights to at least one form of the invention.
CROSS REFERENCE TO RELATED APPLICATIONS
[0002] None.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to an infrared detector having photocurrent responses from near infrared to very long wavelength infrared at normal and oblique incidences. Specifically, the invention is a quantum-well infrared photodetector composed of group III-V nitrides.
[0005] 2. Description of the Related Art
[0006] Infrared detectors are found in a wide variety of imaging applications, including night vision goggles, surveillance satellites, and seekers. Technical advances continue to increase the resolution and range of infrared systems and to lower their operational costs.
[0007] Second-generation infrared systems include two-dimensional focal plane arrays functioning as either photon or heat detectors. Photon detector systems include mercury cadmium telluride (MCT) elements in a pixelized arrangement so as to detect long-wavelength infrared (LWIR, 8-12 μm), and MCT and indium antimonide (InSb) elements in a pixelized arrangement so as to detect medium-wavelength infrared (MWIR 3-5 μm). Heat or thermal detectors include microbolometers and pyroelectric sensors. Such devices do not require cooling and therefore are lighter and less expensive than photon detectors. However, microbolometers and pyroelectric sensors are resolution and range limited.
[0008] Third-generation infrared systems are separable into three distinct design approaches, namely, large format two-dimensional focal plane arrays, multi-spectral detection and correlation at two or more wavelengths, and longer wavelength sensing.
[0009] Exemplary third generation detectors include multi-spectral MCT, antimonide-based devices, and quantum-well infrared photodetectors (QWIPs). MCT technology has been demonstrated in focal plane arrays having as many as four million pixels sensing infrared wavelengths up to 17 μm. However, large format focal plane arrays suffer uniformity and operability problems in the range of LWIR. Theoretically, antimonide-based devices are wavelength tunable and capable of quantum efficiencies exceeding 80%. However, material and surface problems limit detector performance in practical applications. QWIPs facilitate large format focal plane arrays and multiple spectral detection in the range of MWIR and LWIR. However, arsenide-based devices, such as those described and claimed by Gunapala et al. in U.S. Pat. No. 6,734,452 B2 and U.S. Pat. No. 6,211,529 B1, have a low quantum efficiency (10-20%), require cooling, and fail to detect infrared around 37 μm.
[0010] Both second and third generation devices are unable to absorb normal incident light. Gratings and beveled edges are employed to correct this deficiency. However, both approaches increase complexity and cost and degrade performance by increasing crosstalk.
[0011] While nitride-based compositions have been applied to multiple quantum wells in light emitting diodes and lasers, application to far infrared detectors is not found in the related arts. Furthermore, quantum well structures within diodes and lasers are simply too conductive for far infrared detection. For example, a quantum well within a typical diode or laser has an electron concentration exceeding 10 18 cm −3 , thereby reflecting infrared light at wavelengths above 33 μm. Since wavelengths as high as 100 μm are needed for some far infrared detector applications, it is desired to have a free electron concentration less than 10 18 cm −3 .
[0012] What is currently required is an infrared detector with improved sensitivity and capable of operating at higher temperatures so as to extend the operational range of imaging systems.
SUMMARY OF THE INVENTION
[0013] An object of the present invention is to provide a quantum-well infrared photodetector with improved sensitivity.
[0014] Another object of the present invention is to provide a quantum-well infrared photodetector capable of detecting long-wavelength infrared.
[0015] Another object of the present invention is to provide a quantum-well infrared photodetector having a lower cost as compared to arsenide-based devices.
[0016] The present invention includes a substrate, a buffer layer, a first conductive layer, a multiple quantum well, an optional blocking layer, and a second conductive layer. Substrate is composed of a monocrystal oxide or carbide, examples including sapphire (Al 2 O 3 ) and silicon carbide (SiC), respectively. Substrate may be removed after fabrication. Remaining layers are composed of group III-V nitride compounds. First and second conductive layers are electrically connected to a current sensing device.
[0017] Group III-V nitrides are comprised of elements selected from group III, namely, aluminum (Al), gallium (Ga), and indium (In) and the group V element nitrogen (N). Nitride-based compositions include binary alloys, examples including gallium nitride (GaN) and aluminum nitride (AlN), ternary alloys, examples including aluminum gallium nitride (AlGaN) and indium gallium nitride (InGaN), and quaternary alloys, an example being aluminum indium gallium nitride (AlInGaN). Group III-V nitrides have a wide band gap range so as to cover a wavelength band from visible to ultraviolet light.
[0018] Alternate embodiments of the present invention include a doped binary alloy along first and second conductive layers and/or wells, a binary or ternary alloy along buffer layer, and alternating layers of binary, ternary and quaternary alloys within the multiple quantum well.
[0019] Several advantages are offered by the present invention.
[0020] First, the invention increases the electron effective mass thereby reducing leakage current. Current leakage has two primary sources, namely, thermionic emissions (TE), resulting from the direct excitation of electrons to the continuum band, and field-induced emissions (FIE), due to thermally assisted tunneling. TE leakage is reduced as it is inversely related to electron effective mass. Likewise, FIE leakage is reduced since tunneling probability is proportional to exp[−A(m*)½], where A is a constant related to barrier height and electric field and m* is the electron effective mass.
[0021] Second, the invention minimizes effects of dislocations and interfaces thereby achieving a higher quantum efficiency-mobility-lifetime product (ημτ product) than group IV, non-nitride group III-V, group II-IV and telluride-based compositions. Group III-V nitrides achieve a ημτ product in the range of 10 −1 to 10 cm 2 /V.
[0022] Third, the invention responds to normally incident infrared light.
[0023] Fourth, the invention functions in the broad wavelength window from 2 μm to over 80 μm.
[0024] Fifth, the invention is easier to manufacture and process as compared to compositions including arsenic, mercury, and cadmium, and more environmentally friendly.
[0025] Sixth, the invention achieves a higher signal-to-noise ratio than similar infrared sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Details of the present invention are described in connection with the accompanying drawings, in which:
[0027] FIG. 1 is a schematic diagram of the present invention showing a single quantum-well infrared photodetector.
[0028] FIG. 2 is a schematic diagram of the present invention showing a single quantum-well infrared photodetector with optional blocking layer between second conducting layer and multiple quantum well.
[0029] FIG. 3 is a schematic diagram of a focal plane array composed of a plurality of quantum-well infrared photodetectors.
[0030] FIG. 4 is a schematic diagram describing the operational principle of a quantum-well infrared photodetector.
[0031] FIG. 5 is an example chart of responsivity versus wavelength showing photocurrent response of a quantum-well infrared photodetector for short to long wavelength infrared at normal incidence.
[0032] FIG. 6 is an example chart of responsivity versus wavelength showing photocurrent response of a quantum-well infrared photodetector for very long wavelength infrared at normal incidence.
REFERENCE NUMERALS
[0000]
1 Detector
2 Substrate
3 Buffer layer
4 First conducting layer
5 Multiple quantum well
6 Barrier
7 Well
8 Second conducting layer
9 a - 9 b Contact
10 Current sensing device
11 a - 11 b Lead
12 Blocking layer
21 Focal plane array
22 Detector
23 Row
24 Column
25 Height
26 Width
DESCRIPTION OF THE INVENTION
[0051] FIGS. 1 and 2 describe exemplary embodiments of the present invention. FIG. 3 describes the application of detectors 1 in FIGS. 1 and 2 to a focal plane array 21 . FIG. 4 graphically represents the functional performance of devices shown in FIGS. 1 and 2 . FIGS. 5 and 6 describe the performance of the present invention at near to long and very long wavelengths, respectively. Drawings are not to scale.
[0052] Referring now to FIG. 1 , a detector 1 is shown having a substrate 2 , a buffer layer 3 , a first conducting layer 4 , a multiple quantum well 5 , and a second conducting layer 8 . Layers are contacting and attached in the order described. Conductive contacts 9 a and 9 b are provided along one surface of the first conducting layer 4 and second conducting layer 8 , respectively. Each contact 9 a and 9 b is thereafter electrically connected to a lead 11 a and 11 b, respectively. Leads 11 a and 11 b are electrically connected to a current sensing device 10 . Leads 11 a, 11 b and current sensing device 10 include elements understood in the art.
[0053] Referring now to FIG. 2 , the detector 1 is shown having a blocking layer 12 between, contacting, and attached to the second conducting layer 8 and multiple quantum well 5 . The blocking layer 12 can be used to further optimize the signal from the detector 1 .
[0054] The multiple quantum well 5 is composed of barriers 6 and wells 7 arranged in a layered fashion, as shown in FIGS. 1 and 2 . Layers are contacting and attached. The number of wells 7 or periods within a design is performance and application dependent. Although more periods are generally desired, too many may induce structural disorder within the multiple quantum well 5 . As such, it was preferred to have no more than 100 wells 5 because of the limitations inherent to presently known deposition technologies. However, it is recognized that more wells 5 may be possible as such technologies mature.
[0055] The thickness of barriers 6 and wells 7 is likewise performance dependent. In general, the heavier electron effective mass of group III-V nitrides allows for thinner barriers 6 as compared to those described in the art. For example, a barrier 6 having a thickness up to 100 nm was adequate for many applications. Preferred embodiments favored a thickness from 15 nm to 40 nm so as to minimize material and growth time and to approximate the tunneling probability of gallium arsenide (GaAs) at a thickness greater than 40 nm. A well 7 having a thickness from 1 nm to 10 nm was likewise adequate for many applications. However, it was preferred to have a well 7 with thickness from 3 nm to 6 nm and a barrier height of 300 meV or less for long infrared detection applications.
[0056] TABLE 1 identifies materials applicable to the various layers within embodiments in FIGS. 1 and 2 .
TABLE 1 Layer Composition Preferred Substrate (2) Oxides Sapphire Carbides SiC Binary III-V nitrides GaN Buffer layer (3) Binary III-V nitrides Ternary III-V nitrides First conducting Binary III-V nitrides Doped GaN layer (4) Ternary III-V nitrides Quaternary III-V nitrides Multiple quantum Binary/Binary III-V nitrides well (5) Ternary/Ternary III-V nitrides Quaternary/Quaternary III-V nitrides Binary/Ternary III-V nitrides Ternary/Quaternary III-V nitrides Binary/Quaternary III-V nitrides Ternary/Binary III-V nitrides Quaternary/Ternary III-V nitrides Quaternary/Binary III-V nitrides Barrier (6) Binary III-V nitrides GaN Ternary III-V nitrides AlGaN Quaternary III-V nitrides Al x In y Ga 1-x-y N Well (7) Binary III-V nitrides GaN Ternary III-V nitrides InGaN Quaternary III-V nitrides Al x In y Ga 1-x-y N Second Binary III-V nitrides Doped GaN conducting layer Ternary III-V nitrides (8) Quaternary III-V nitrides Blocking Binary III-V nitrides GaN layer (12) Ternary III-V nitrides AlGaN Quaternary III-V nitrides
[0057] TABLE 2 summarizes exemplary thickness ranges and electron concentrations for each layer. Specified thickness values are not limiting and highly design and performance dependent.
TABLE 2 Layer Thickness (nm) Typical Electron Concentration Substrate (2) ≦7,000 Buffer layer (3) ≦100 First conducting ≦3,000 ≧10 18 cm −3 layer (4) Barrier (6) ≦100 <1 × 10 17 cm −3 Well (7) ≦10 >1 × 10 17 cm −3 Second conducting ≦3,000 ≧10 18 cm −3 layer (8) Blocking layer (12) ≦100 ≦10 17 cm −3
[0058] While a variety of known manufacturing methods are applicable to fabricating the detector 1 , it was preferred to use a metal oxide chemical vapor deposition (MOCVD) process for the epitaxial growth of nitride-based materials.
[0059] The process described below was employed to establish quality of growth, ημτ product, electron mobility and concentration, and growth and etch rates. While specific materials are referenced, the described method is applicable to other material systems in TABLE 1.
[0060] Substrate 2 is comprised of a composition capable of nitride growth. While a variety of compositions are known and used within the art, it was preferred for the substrate 2 to have a monocrystal structure and composed of either an oxide or carbide, examples including Al 2 O 3 and SiC, respectively. It was likewise possible for the substrate 2 to be a binary group III-V nitride, one example being GaN. Substrates 2 were fabricated via processes known within the art.
[0061] Next, a buffer layer 3 composed of undoped GaN or InGaN or AlN was grown onto the substrate 2 . Undoped GaN was applied via a MOCVD process including ammonia and TMG using parameters and procedures understood in the art. Undoped InGaN was applied via a MOCVD process including ammonia, TMG, and thimethylindium (TMI), also using parameters and procedures understood in the art. For example, a 20 nm thick buffer layer 3 of GaN or InGaN or AlN was achieved by the steps including high temperature (1030° C.) anneal in ammonia and layer growth at low temperature (550° C.).
[0062] Next, a first conducting layer 4 was grown onto the buffer layer 3 . For example, a 2,000 nm thick layer of GaN was grown onto the surface of the buffer layer 3 opposite the substrate 2 at a temperature of 1030° C. It was preferred to have the first conducting layer 4 doped with silicon so as to have an electron concentration (EC) of at least 10 18 cm −3 . Ohmic contact to the multiple quantum well 5 was provided through the first conducting layer 4 . The first conducting layer 4 may also function as a reflection mirror for long wavelength infrared so as to increase response of the detector 1 .
[0063] Next, the growth temperature was lowered to the range of 750° C. to 800° C. for growth of barriers 6 and wells 7 within the multiple quantum well 5 . The multiple quantum well 5 was fabricated via the sequential and separate growth of barrier 6 and well 7 layers. While a wide thickness range is possible for barriers 6 and wells 7 , it was preferred to have a barrier 6 with a thickness less than 100 nm and a well 7 with a thickness no greater than 10 nm. For example, multiple quantum wells 5 having a total thickness from 200 nm to 500 nm were demonstrated composed of InGaN wells 7 each having a thickness of 3 nm to 6 nm and GaN barriers 6 each having a thickness of 15 nm to 40 nm.
[0064] Films were examined for electrical and photoluminescence via techniques understood in the art. For example, photoluminescence measurements quantified band edge luminescence, Hall Effect measurements quantified electron mobility and concentration, and x-ray diffraction (XRD) qualified the microstructure. Films having an electron concentration (EC) greater than 10 18 cm −3 were rejected. Band edge luminescence and XRD were used to estimate band gap energy and lattice constants for InGaN films. It was desired for the films to have a high photoconductivity-to-dark-conductivity ratio. Photoconductivity spectra measurements from visible to UV, via methods understood in the art, were used to reveal defect states within band gaps and surface recombinations.
[0065] It was preferred for the electron concentration (EC) in wells 7 to exceed that in the barriers 6 . For example, typical barriers 6 were undoped and had an electron concentration less than 5×10 17 cm −3 . In thermal equilibrium, electrons from the GaN barriers 6 are transferred to the InGaN wells 7 . Preferred wells 7 had an electron concentration greater than 5×10 17 cm −3 . Electron concentrations were found to be dependent on the mole fraction of indium, growth temperatures, and relative thickness between wells 7 and barriers 6 . In some embodiments, it may be desired to dope the wells 7 with silicon to further increase the electron concentration differential between barriers 6 and wells 7 .
[0066] Next, a second conducting layer 8 was grown onto the multiple quantum well 5 opposite of the first conducting layer 4 . For example, a 150 nm thick layer of GaN was grown onto the surface of the barrier 6 opposite of the substrate 2 at a temperature of 1030° C. It was preferred to have the second conducting layer 8 doped with silicon so as to increase the electron concentration to at least 10 18 cm −3 . Ohmic contact to the multiple quantum well 5 was provided through the second conducting layer 8 .
[0067] An optional blocking layer 12 can be used between multiple quantum well 5 and second conducting layer 8 in some embodiments. For example, a 20 nm thick layer of undoped GaN may be grown onto the surface of the multiple quantum well 5 opposite of the first conducting layer 4 at a temperature of 1030° C. Thereafter, a second conducting layer 8 was grown onto the blocking layer 12 via the method described above. Ohmic contact to the multiple quantum well 5 should be maintained between multiple quantum well 5 and second conducting layer 8 .
[0068] First conducting layer 4 , multiple quantum well 5 , second conducting layer 8 , and optional blocking layer 12 were each inspected by one or more of the methods described above. Photoluminescence measurements were used to quantify band edge luminescence, Hall Effect measurements to quantify electron mobility and concentration, and x-ray diffraction (XRD) to qualitatively assess the microstructure. Band edge luminescence and XRD were used to estimate band gap energy and lattice constants. Photoconductivity spectra measurements from visible to UV, via methods understood in the art, were used to reveal defect states within band gaps and surface recombinations.
[0069] Contacts 9 a and 9 b were provided on first conducting layer 4 and second conducting layer 8 , respectively, to facilitate ohmic contact between the mentioned layers and leads 11 a and 11 b. The surface of both first conducting layer 4 and second conducting layer 8 were etched using reactive ion etching in a chlorine plasma, a method known within the art, to expose the underlying n-type GaN layer. A conductive metal, preferably a double layer gold-titanium film, was thereafter deposited onto the exposed surface via evaporation, also a method understood in the art. Contacts 9 a and 9 b may be annealed after deposition to improve their contact properties.
[0070] The etch process may include photoresist methods understood in the art. For example, a photoresist mask may be applied onto selected surface regions of the second conductive layer 8 . Thereafter, a chlorine-based plasma is used to etch the unmasked regions of the GaN to expose an underlying GaN layer. Thereafter, a second mask procedure may be applied to the GaN that later separate top and bottom contact regions. Thereafter, metal is evaporated and deposited onto non-masked and masked regions. A metal lift-off process is then performed so as to leave metal contacts 9 a and 9 b in the desired locations.
[0071] Referring now to FIG. 3 , a focal plane array 21 is shown including a plurality of detectors 22 arranged in rows 23 and columns 24 and mounted onto a single wafer. Each detector 22 was preferred to be dimensionally identical so as to have a common height 25 and width 26 . It was likewise preferred for detectors 22 to have a height 25 and width 26 at least five times the wavelength to be detected and small as possible so as to maximize their density within an array. For example, a detector 22 having a nominal height 25 and width 26 of 50 μm enabled a pixelized array as large as 512-by-512 detectors 22 on a 50.8 mm diameter wafer.
[0072] While detectors 22 may be individually manufactured and thereafter assembled into a focal plane array 21 , it was preferred to fabricate large dies, one example being a 50.8 mm wafer with 256-by-512 sensors. Thereafter, the wafer was diced, via a mechanical method understood in the art, to form an individual array.
[0073] Indium bumps may be applied to serve as electrical interconnections between detectors 22 and a read-out unit cell (ROIC), one example being an Amber series ROIC, following metallization and dicing steps described above. Indium is preferred since it remains ductile at the temperature of liquid helium and forms a good bond at room temperature. Evaporation and liftoff methods understood in the art are used to fabricate indium bumps. Before evaporation of the indium bump, an under bump metallurgy (UBM) layer is deposited to anchor the indium bump to the lead 9 a , 9 b . It is desired to achieve a bump having a nearly uniform height. Next, flip-chip bonding using a flip-chip aligner secured the detector 22 to the ROIC. The gap between focal plane array 21 and ROIC is a function of bonding pressure and bump height. Next, an underfill is applied between focal plane array 21 and ROIC to improve the mechanical strength of the now bonded focal plane array 21 and ROIC assembly and to minimize thermal expansion there between. Likewise, underfill protects both focal plane array 21 and ROIC from moisture and other contaminants and may mitigate shock and vibration effects. Thereafter, the substrate 2 is abrasively polished via methods understood in the art. Polishing may remove stresses induced by thermal expansion which accumulate during manufacture. Furthermore, polishing may eliminate optical crosstalk between pixels, and significantly enhance optical coupling of infrared radiation into the detector 22 , since a sapphire-based substrate 2 is generally not transparent beyond 7,000 nm. Finally, the focal plane array 21 and ROIC are bonded onto a lead-free ceramic chip carrier (LCCC) via a die-bonding method understood in the art. Input/output metal pads on the ROIC are connected to pins along the LCCC by a wire bonding process, also understood in the art.
[0074] Referring now to FIG. 4 , a single well 7 is shown between a pair of barriers 6 such that the vertical axis represents energy and the horizontal axis represents position. In principle, electrons within the well 7 have an initial energy, E 0 , corresponding to a ground state. Electrons within the well 7 are excited to a state having an energy, E 1 , when infrared light is absorbed by the multiple quantum well 5 . Excited electrons contribute to the photocurrent response perpendicular to the plane of the multiple quantum well 5 , thus sensing infrared light. Likewise, transitions from donor or defect levels to sub-band levels, or from donor levels to continuum states, or from sub-band levels to continuum states, also contribute to infrared sensing.
[0075] The performance of the detector 1 is tailored to the specific application via the composition of layers so as to yield the desired performance. The multiple quantum well 5 is optimized via material composition, element content, and thickness. For example, barriers 6 may be composed of a binary alloy, a ternary alloy, including aluminum gallium nitride (AlGaN), or a quaternary alloy, including indium gallium aluminum nitride (InGaAlN). Aluminum and indium content may be varied to tailor the performance of individual barriers 6 . It was preferred for the content of indium not to exceed 20%, on a molar basis. Likewise, wells 7 may be composed of a binary alloy, one example being gallium nitride (GaN), a ternary alloy, one example being InGaN, or a quaternary alloy.
[0076] Transition energies (E 1 -E 0 ) are greatly influenced and controlled by the thickness and height of the barrier 6 and the thickness of the well 7 . Each barrier-well pair has a thickness and height at which the first excited state exhibits an energy level just at the top of the barrier 6 . The first excited state is no longer a bound state when the quantum well is thin and exhibits energies deep into the well 7 when the quantum well is thick. The latter reduces the probability of tunneling through the barrier 6 .
[0077] The group III-V nitride AlInGaN possesses a built-in electric field thereby allowing the effective height of the barrier 6 to be lower in multiple quantum wells 5 . During electron transfer, wells 7 are generally negatively charged and barriers 6 are positively charged resulting in an electric field pointing from barrier 6 to well 7 . The resulting electric potential is lower in the well 7 than in the barrier 6 , and resultantly the electron energy (eV) is higher in wells 7 than in the barriers 6 . The effectively lower height for barriers 6 moves the transition energy to lower wavelengths and aligns the first excited state to the top of the barrier 6 .
[0078] Referring now to FIG. 5 , an exemplary responsivity profile is shown for a detector 1 without blocking layer 12 composed of group III-V nitrides having a GaN/InGaN multiple quantum well 5 . Infrared response curves were measured using a FTIR system. Responsivity was calculated using a geometrical factor of ten corresponding to a solid angle of 0.2π and flux covering the detector 1 in a full and uniform fashion. In practice, the incident light covered an area wider than the active area of the detector 1 so that actual responsivity may be a factor of 2 higher.
[0079] In FIG. 5 , the photocurrent response is shown for 10 mV, 30 mV, and 50 mV under normal incidence. Several observations are noteworthy. The termination of spectra at 22 μm is an artifact of the KRS window. Peak responses are seen at 2.0 μm, 12.5 μm, 14 μm and 20 μm. The spike at 8 μm is attributed to noise. The level response at 13.5 μm is due to LO-phonon absorptions in GaN. The absence of a response around 16-17 μm may be due to TO-phonon absorptions in GAN or a significant decrease of the absorption from sub-band levels. The drop-off at 12 μm is attributed to the first interference minima corresponding to 2 (n)(d), where n is the refractive index and d is the overall GaN film thickness.
[0080] The selection rule prohibits optical absorption for normally incident light by a quantum well. However, detectors 1 described in FIGS. 1 and 2 were responsive to infrared light at normal and oblique incidences. While not intending to be bound by theory, several explanations are possible. It is possible that an inhomogeneous distribution of indium within the quantum well alters the translational symmetry along quantum well directions so that dipole terms in x and y directions are no longer zero. It is also possible that quantum boxes are embedded within the quantum wells and responsive to normally incident light.
[0081] Referring now to FIG. 6 , an exemplary responsivity profile is shown for a detector 1 without blocking layer 12 composed of group III-V nitrides having a GaN/InGaN multiple quantum well 5 . Spectral measurements were taken for the detector 1 mounted at normal incidence with a white polyethylene FIR window having an OPD of 0.05 cm/s. The threshold wavelength of the detector 1 is approximately 65 μm for a forward bias of 0.1V. A threshold wavelength for a reverse bias voltage was not obtained, since response peaks were observed around 68 μm and 88 μm. A responsivity as high as 350 mW/A was observed under reverse bias. Responsivity is not symmetric with respect to the bias, eight times higher at reverse bias than at forward bias, indicating the presence of a built-in electric field.
[0082] Signal peaks at 2 μm and 8-12 μm were observed at forward and reverse bias. The responsivity peak at 2 μm is believed to result from a donor-to-continuum transition or a defect-to-continuum transition in the InGaN wells 7 . Peaks in the range of 8 to 12 μm are attributed to a bound-to-bound transition in the multiple quantum well 5 . Identified peaks beyond 20 μm are signals rather than noise as they are nearly identical in forward and reverse bias. Furthermore, interference is unlikely because the sapphire substrate 2 is non-transparent beyond 7 μm. These peaks may arise from bound to continuum transitions.
[0083] The description above indicates that a great degree of flexibility is offered in terms of the present invention. Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
INDUSTRIAL APPLICABILITY
[0084] As is evident from the above explanation, the described invention provides low noise, high resolution and operability, and high pixel uniformity. The robustness of the invention improves image quality achieved by and range of focal plane arrays composed of group III-V nitride elements.
[0085] Accordingly, the described invention is expected to be utilized as detectors in focal plane arrays for night vision, navigation, weather monitoring, security, surveillance, defense systems, and chemical and biological detection.
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A quantum-well infrared photodetector (QWIP) is presented. The photodetector includes a substrate, a buffer layer, a first conductive layer, a multiple quantum well, an optional blocking layer, and a second conductive layer. Substrate is composed of a monocrystal which may be removed after fabrication. Remaining layers are composed of group III-V nitrides, including binary, ternary, and quaternary compositions. Alternate embodiments of the present invention include a doped binary alloy along first and second conductive layers, a binary alloy along buffer and blocking layers, and alternating alloys of binary, ternary and quaternary compositions within the multiple quantum well. The present invention responds to infrared light at normal and oblique incidences, from near infrared to very far infrared.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention lies in the field of heat transfer apparatus. More particularly it concerns improving the heat transfer in a convection section of a furnace, by the addition of metal strips which are heated by convection from the flowing combustion gases, and which radiate heat to the pipes carrying the fluid to be heated in the furnace.
2. Description of the Prior Art
In the process industries, where fluid raw materials are converted into more useful or more valuable products through application of heat energy in well known manners to the raw materials, structures which are called "heaters" are employed.
A heater is composed of a furnace or combustion volume; burners to inject fuel into the furnace, in calculated manners, for provision of a supply of heat energy, such as may be required, and a sinuous tubular passage through the burner-heated areas. The tubular passage is entirely within the heated volume and spaced from the furnace structure.
The tubular passage is for closed transport of the fluid to be heated through the furnace areas where, due to burner-produced heat energy, the fluid, as it flows through the tubular passage, receives heat energy through a process which is typically identified as heat transfer -- that is, the heat energy which is supplied to the furnace areas passes through the wall of the tubular passage to enter the flowing fluid. Such heat-energy transfer results in increase in the state of molecular motion with the flowing fluid, and since absolute temperature varies as the square of the average molecular motion, the temperature of the flowing fluid is caused to rise to a preferred or required level.
In such processing action, it is not possible to recover all of the burner-produced heat for transfer to the flowing fluid, since residual combustion gases, vented to atmosphere after all possible heat recovery, are at temperature which is hundreds of degrees above the temperature of fuel and air supplied for burning. This residual gas temperature (stack temperature) is useful in that, because of it, the stack or chimney can produce `draft` or less-than-atmospheric pressure inside the furnace. The less-than-atmospheric pressure inside the furnace causes a required quantity of air to be drawn into the furnace for mixture with the fuel to permit fuel burning or combustion to occur to a required degree. However, the heating of stack gases results in heat-energy loss such that efficiency of heat recovery (thermal efficiency) seldom exceeds 82% and is typically in the order of 75% or less.
Prior to the fuel/energy crisis, and when supplies of fuel were both plentiful and cheap, there was small concern if the thermal efficiency of a process heater was slightly greater than 70%, and many furnace/heater installations were designed for 70%+ efficiency (not 80%+). These, or many of these, are still in operation to the great distress of their operators because of excessive fuel requirement, when fuel cost has increased many times, and is no longer plentiful. For the average heater, fuel costs per year have increased by hundreds of thousands of dollars, and this amounts to precious fuel wastage.
Design factors of the furnace or heater determine the thermal efficiency to be expected, and 1975 design practice dictates stack temperature at 400° F. rather than 800° F. upward, for added conservation of 11% of fuel burned for a required service, or more. But this is for heaters now being built. For existing heaters there is reason to improve thermal efficiency, as is obvious, but at very great expense for alteration, and at the expense of serious loss of product because the heater cannot be operated during the time the heater is being modified which may take up to 7 days.
In the art of process heater design, and to provide reasonable nomenclature, the heater, per se, is considered as three separate sections. These are the "radiant" section, the "convection" section, and the "stack" section.
Nomenclature for the three sections is based on the service performed by separate sections. Heat transfer is either through radiant effects; through convective effects or both, while the stack vents combustion gases to atmosphere while providing draft for induction of combustion-supporting air, or maintenance of less-than-atmospheric pressure within the heater structure. Preponderance of heat transferred is in the radiant section (typically 80% of total heat transferred) with smaller quantities of heat (typically 20%) transferred in the convection section. This heat transfer relative state is due to two factors. The first is that, in reference to relative heat transfer per square foot of tubular heat transfer surface, the higher combustion chamber temperature, plus effects of radiant heat transfer, plus certain convection effect causes greatest heat transfer to occur in the "radiant" section area. Even if the "radiant" and "convection" heat transfer surface areas should be equal, a significant preponderance of heat transfer would occur in the "radiant" areas. The "radiant" areas are defined as the areas which can "see" the burner flames and radiant combustion chamber surfaces, where these surfaces are typically formed of refractory material. The "convection" areas are defined as areas of tubular heat transfer surfaces which cannot see the burner flames or radiant combustion chamber surfaces. In all areas, there is some heat transfer by both mechanisms, according to the relative emissivities and temperatures of the radiant heat sources.
Emissivity denotes ability to emit radiation of energy as heat. The emissivity of heated gases (due to the presence of binary molecules such as CO 2 , H 2 O and SO 2 --SO 3 ) is quite small and is typically 0.05, while the emissivity of refractory surfaces can be considered, typically, as 0.80 or greater (16 times greater or more). Radiant heat is as infra-red emission which is predominantly absorbed by, but partially reflected from the tubular heat transfer surfaces, according to the absorptivity of the surfaces. Relative absorptivity of surfaces is according to Kirchoff's Law which teaches that ability to emit is equal to ability to absorb. Radiant heat transfer between bodies is according to the Stefan-Boltzmann Law (Perry's Chemical Engineers' Handbook).
Convective heat transfer is due to flow of fluids, where the quantity of heat energy transferred is proportional to flow mass-velocity and temperature difference, and in the case of process heaters, the fluid is heated combustion gases from which a significant portion of combustion heat has been removed.
Thus, the convection section becomes a part of process heaters as means for final recovery of combustion heat (an `economizer`) as the combustion gases are compelled to give up heat energy as they move toward final venting to atmosphere, and total loss of residual heat energy, but in many existing process heaters, the convection section is far from adequate for suitable heat recovery. As has been pointed out, very expensive and time-consuming means for added heat recovery are available for these heaters. But in many cases, because of either high cost or because of lost process time, there is great reluctance to apply these means to heaters, and as a result, the heater operation is both wasteful of fuel and more expensive.
Earlier delineation of heater nomenclature as the "radiant section" as the "convection section" is convenient but not accurate. Radiation of heat energy between two adjacent bodies immediately begins to occur when the temperature of one body exceeds the temperature of the adjacent body. Heat energy transferred is related to the fourth-powers of the absolute temperatures; it is also proportional to emissivity and absorptivity.
SUMMARY OF THE INVENTION
As has been discussed, radiant heat transfer is most effective, and any improvement in convected heat transfer, without the addition of convective heat transfer area, is best realized through addition of radiant heat transfer to convection areas such as they may be. Combustion gases, which contain binary gases, have the very low radiant factor of 0.05 typically, so a form of enhanced radiant effect is to be had through addition of material which is combustion gas-heated and has far more emissive surface to convection areas. The emissivity of steels ranges from 0.79 to 0.94 (Process Heat Transfer, Kern, McGraw-Hill). Emissivity of the stainless-steels, which are required for heat resistance, average at 0.80. Thus, through the addition of steel surfaces to convection areas, radiant heat transfer is increased in the ratio of 0.80/0.05 to result in increased heat transfer in these areas, for greater total heat recovery and greater thermal efficiency in heater operation.
It is a primary object of this invention to provide an apparatus which can be installed in a furnace in the convection section, at minimum cost, and minimum shut down time, whereby the heat transfer efficiency from the combustion gases venting to the stack can be improved.
This and other objects are realized and the limitations of the prior art are overcome in this invention by providing a plurality of metal strips of the proper composition to withstand temperature, etc. These strips are loosely hung on and supported by the horizontal pipes which are in the furnace, and through which flow the fluids to be heated by the furnace.
The strips are supported on the pipes and thread diagonally between the pipes. They are attached to horizontal strips which rest on the top row of the pipes. The strips are maintained with their surfaces vertical, so as to minimize the reduction in cross sectional area of the space through which the combustion gases flow. A plurality of such sets of strips are placed on the pipes. These are spaced from each other in equal, or in random, spacings, as desired, and in a number such that the more the better, provided the presence of additional sets of strips does not increase the flow resistance to the point where additional stack height or other means is required to provide the input of sufficient combustion air for the furnace.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of this invention and a better understanding of the principles and details of the invention would be evident from the following description taken in conjunction with the appended drawings in which:
FIG. 1 illustrates an elevation view of the convection section of a furnace showing the heating pipes in cross section, and the presence of the apparatus of this invention.
FIG. 2A illustrates a plan view of a portion of the apparatus which is added to the furnace.
FIG. 2B illustrates a cross section of one strip taken along the plane 2--2 of FIG. 1.
FIG. 3 is a plan view of the apparatus taken along the plane 3--3 of FIG. 1.
FIG. 4 is a sketch of a prior art furnace showing in a general way the relative parts of the furnace in which the principle heat transfer is by radiation and by convection.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1 there is shown a vertical cross section through the convection section of a furnace, in which a plurality of pipes 10 are shown in spaced position in a series of horizontal planes. Each of the pipes is connected at its ends to adjacent pipes, so as to form a continuous, sinuous conduit for the passage of a fluid to be heated in the furnace. These pipes are placed within a portion of the furnace comprising walls 16 of suitable material, and lined 14 with ceramic as necessary, and as is well known in the art. As will be shown in FIG. 4, the hot products of combustion flow in accordance with the arrows 30 vertically through and in contact with the surfaces of the pipes 10, and up to a stack which is not shown in FIG. 1 but is indicated in FIG. 4.
As previously discussed, the purpose of this invention is to increase the heat transfer from the combustion gases 30, to the pipes 10 and to the fluid within the pipes. The heat transfer from the gases to the pipes is mainly by convection, and involves actual contact with the surface of the pipe, since the ability of the cooled combustion gases to radiate energy is minimal.
A plurality of thin planar strips 20 of metal are supported by a strip 18 which rests with its plane vertical, on top of the top row of pipes 10.
Supported from the top strip 18 are a plurality of strips 20A, 20B, 20C . . . 20N which are attached loosely to one surface of the strip 18, and hang at an angle to the vertical, resting on the pipes as indicated. There is a second set of strips 22A, 22B . . . 22N which are supported from the strip 18 at its opposite surface, and which hang at an opposite angle, and are supported by the pipes as indicated in FIG. 1. Of course, the particular arrangement and spacing and angles of the strips as they are supported from the strip 18 will depend materially on the particular arrangement of pipes and their spacing in rows and columns.
In general, however, a planar arrangment of metal surfaces is desired, with as much surface area as possible, such that with the vertically flowing combustion gases heat will be transferred by convection from the gases to the strips to raise their temperature, and hopefully raise their temperature higher than the temperature of the pipes, so that net heat will be radiated from the strips to the pipes.
Referring now to FIG. 4, which is a prior art illustration, there is shown, as a typical example, a furnace 50 having a radiant section comprising a housing of walls 56, floors 53 and ceiling 55. There are a plurality of burners 54 injecting combustible fluid into the furnace for its combustion therein, and to provide a flow of air to the burners for the combustion. The air is inducted into the burning zone due to the draft created by the flow of hot products of combustion up through the convection section 63 and to the stack 58, to the atmosphere.
The furnace is provided for the purpose of heating some liquid, such as crude oil, in a refinery, for example. The oil flows into the furnace through pipe 59 and through a plurality of sections which are interconnected indicated by the numeral 60. These are placed in the upper portion of the heater in an area called the convection section, because pipes in that area are not in direct view of the luminous radiating surfaces of the furnace walls 56. The pipes 60 are in the coolest portion of the system, and are connected through a pipe 61 to a series of pipes 62, 64, 66, and to an outlet 68. The pipes 62, 64, 66 are mounted in planes which are parallel to but separated from the walls and roof of the furnace. The purpose of this is to provide for free flow of flame and combustion gases around the pipes so that the gases might transfer heat by convection to the walls and the pipes, and also so that the pipes will receive heat from the radiating walls of the furnace.
It is the pipe sections 60 in the convection section of the heater that can benefit most by the improvement of this invention, and this is the area of the heater to which this invention is directed.
Choice of metal for the strips is based upon the consideration of the temperature to be expected and the emissivity characteristic of the metal to be chosen as the radiant material. The character of the metal must remain substantially constant with increased life to provide sufficient duration of operation to make the installation practical. Stainless steel is an ideal material.
FIG. 3 illustrates a plan view of the pipes 10, and the plurality of strips 18 spaced along the length of the pipes.
As shown in FIG. 2A the strips 20, 22 can be loosely attached to the horizontal strip 18 by pins as shown, or by screws and nuts, by cotter pins and the like.
FIG. 2B illustrated how the hot combustion gases 28 flowing parallel to the surfaces of the strip 22 will transfer heat by convection to the strips, thus raising their temperatures and permitting them to radiate heat to the pipes.
While the strips are shown in this description as diagonally hanging strips, with vertical plane, they may be configured in other ways, particularly if the pipes are arranged in another order.
Also thin sheets of metal 21 may be hung along the walls 14, spaced from the walls so as to permit the flow of combustion gases 23 on both sides of the sheet.
While the invention has been described with a certain degree of particularity it is manifest that many changes may be made in the details of construction and the arrangement of components. It is understood that the invention is not to be limited to the specific embodiments set forth herein by way of exemplifying the invention, but the invention is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element or step thereof is entitled.
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Apparatus for improved recovery of heat from combustion gases in the convection section of a furnace by improved radiant heat transfer. Thin strips of selected metals are arrayed and supported on the fluid carrying pipes in the furnace, in such a way that interference to the vertical flow of combustion gases is held to a minimum. The metal strips are heated by flow parallel to their surfaces of the combustion gases. Heat is radiated from the metal strips to the pipes with a consequent increase of heat transfer to the fluid within the pipes.
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This application is a continuation-in-part of U.S. application Ser. No. 09/802,981 filed Mar. 12, 2001, now U.S. Pat. No. 6,435,122.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recessed line holder for a boat fender. More specifically, the recessed line holder provides a passage through which a line is fed. Once the line has been fed through the line holder, the line is secured to position the boat fender at a desired location.
2. Background Art
When a boat is being docked, it is common to position several fenders along the side of the boat so that the fenders are positioned between the side of the hull of the boat and the dock to cushion any impact. Quite commonly these fenders are elongate cylindrical members that are connected at one or both ends to a rope that in turn is tied or attached by tying the rope around the railing of the boat. The ropes used to secure the fender are usually fed through either a grommet or other hook on the fender.
Various structures have been used as boat fenders, especially for absorbing impact and protecting the boat following docking contact. Such bumpers or fenders commonly assume the configuration of cylinders or rollers and are commonly suspended by lines along the sides of the boat hull. The fenders are principally designed to absorb impact although they have some braking action from frictional contact of the elastomeric material with the docking structure.
Any device or system that is used on a boat should also be reliable, easily stowable (if it is to be stowed) and also convenient to mount or dismount (or connect or disconnect) if that is part of the function of the device. Further, nautical devices should be easy to use and function as intended.
In some instances the grommet or passage, through which the rope is inserted, is located on a tab or periphery surface connected to the fender itself. This tab or periphery surface is subject to potential damage while in storage or actual use of the fender. Since the tab is formed outside the perimeter of the main fender, it may not be manufactured to withstand higher stresses involved with the fender's usage.
Still other fenders have grooves circumventing the perimeter of the structure wherein a rope is wrapped around the fender and a piling of a dock or bulkhead. However, these fenders may become dislodged from the ropes that bind the fender to the dock or bulkhead. Thus, the fender may fall into the water. Similarly, these fenders are difficult to properly position, especially when considering changing tides. These fenders also pose a potential problem with docks that do not have pilings in which to secure such devices.
There is a need for an improved boat fender that provides a means for reliably securing the fender in a position to protect the boat. The fender must also facilitate repositioning in accordance with changing conditions.
SUMMARY OF THE INVENTION
The present invention provides an improved boat fender that reliable protects a boat from damage by a docking structure and centers on the pole or piling of the docking structure.
It is an object of the present invention to provide a boat fender with an outer surface designed to enhance its centering ability with respect to a pole or piling. It is also the object of this invention to prevent slipping out of position and away from the pole or piling while moored to a dock by using a recessed line holder to secure the fender to a line.
The invention achieves the above-stated objectives by providing a bumper structure for a floating vessel, containing an elongated resilient member having a first end and a second end along a longitudinal direction. The resilient member having an outer surface defining a circumference circumscribing the longitudinal direction and at least one recessed line holder positioned on at least one of the circumference circumscribing the longitudinal direction, the first end, and the second end. The recessed line holder is substantially contained within said circumference.
The recessed line holder includes a nook formed from the outer surface depressing inward toward a geometric center of the bumper structure, wherein a first side and a second side are formed along the nook and a bridge connecting the first and second sides such that a passage is formed between a bottom surface of the bridge and the nook.
It is yet another object of the invention to provide a boat fender or bumper that is either inflatable or non-inflatable.
It is yet another object of the invention to provide a boat fender or bumper that may be made of at least one of PVC (e.g., 30 oz., 42 oz.), rubber, foam, or any suitable elastomeric or resilient material.
These and other objectives will be achieved with reference to the following drawings and associated description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the boat fender according to the preferred embodiment of the present invention.
FIG. 2 is a partial view of the recessed line holder of the boat fender of FIG. 1 .
FIG. 3 is a profile view along line 3 — 3 of FIG. 2 showing the long axis of a passageway formed between the bridge and the nook.
FIG. 4 is a profile view along line 4 — 4 of FIG. 2 showing the short axis of a passageway formed between the bridge and the nook.
FIG. 5 is a profile view of an alternate embodiment showing the recessed line holder and the boat fender as a solid object.
FIG. 6 is a profile view of yet another embodiment showing the bridge as a solid structure in combination with a hollow, inflatable boat fender.
FIG. 7 a illustrates a cross sectional view of the boat fender having a circular shape.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the attached drawings, the present invention will now be described in the environment of usage for the boat fender of this invention.
FIG. 1 shows a preferred embodiment of this invention whereby the boat bumper or fender 10 comprises a first end 12 , and a second end 14 with a main body portion 16 extending along a longitudinal length from the first end 12 to the second end 14 . Recessed line guides 18 are located in the main body portion 16 along a surface to facilitate the use of a line 19 in securing the boat fender 10 to a pole or boat (not shown). A plurality of recessed line guides 18 may be formed anywhere on the boat fender 10 . In the preferred embodiment as best seen in FIG. 1, the recessed line guides 18 are located on a top surface of the main body portion 16 . However, it is important to note that one skilled in the art may similarly place the recessed line guides on bottom surface or the back surface of the main body portion 16 . This would allow the boat fender 10 to be suspended in any number of positions to best protect the boat from damage.
The boat fender shown is FIG. 1 is an irregular shape, it should be appreciated that the shape of the boat fender is not an essential element of the invention. The boat fender may be completely circular, or any other shape desired by an individual. Thus the shape as illustrated in the Figures should not be considered as limiting when viewing the invention as a whole.
Even further, the recessed line guides may also be formed on the first end 12 and second end 14 as well, or may be formed to suspend the fender in either a vertical or horizontal position. Recessed line guides formed on the first and second ends 12 , 14 would allow the boat fender to hang suspended with the longitudinal length in the vertical direction.
The recessed line guides or holders 18 will now be described with reference to FIGS. 2-4. FIGS. 2-4 show a line or rope 19 engaging the recessed line guide 18 of FIG. 1 . The line 19 is passed under a bridge 20 formed from the main body portion 16 . The recessed line guide 18 begins where the outer surface 22 of the main body portion 16 depresses inward toward the geometric center of the main body portion 16 to form a nook 24 in the bottom of the recessed line guide 18 . The nook 24 is defined by a concave bottom surface. The nook 24 is made from the same material as that of the boat fender 10 . Centered approximately in the middle and above the nook is the bridge 20 . The bridge 20 is also formed from the same material as that of the entire boat fender 10 . The top surface 22 a of the bridge 20 is flush with the outer surface 22 of the main body portion 16 . This allows the entire boat fender 10 to have a smooth external surface. This arrangement minimizes the necessary space for the boat fender 10 to be stored when not in use and also limits extraneous appendages that may be damaged over time.
The boat fender 10 is formed of materials adequate to endure the rigors and hazards associated with docking structures. The boat fender 10 is preferably a resilient plastic substance; however, any material that exhibits the qualities necessary to withstand the rigors associated with use of the boat fender 10 may also be employed, such as elastomeric materials. The boat fender 10 may be provided with at least one friction abutment member 13 having a higher durability than a material forming the outer contour of the boat fender 10 . The boat fender 10 may be inflatable through a valve 11 positioned on body of the boat fender 10 . The exact positioning of the valve is not critical to the invention. Those skilled in the art can determine the positioning of the valve depending on specific needs.
If the boat fender 10 is inflatable, they the boat fender 10 has an interior chamber 30 as seen in FIGS. 3 and 4. In this instance, the bridge 20 also has a chamber 32 that is openly connected with the interior chamber 30 of the boat fender so that fluid can freely flow therebetween. When the boat fender is inflated, air (or other fluid) fills the interior chamber 30 and then flows into the chamber 32 of the bridge. When the boat fender 10 is deflated, the air is forced out of the interior chamber 30 and chamber 32 to reduce the profile of the boat fender 10 .
In an alternative embodiment shown in FIG. 5, the boat fender 10 is made from an elastomeric material. In this instance, the interior of the boat fender 10 is filled with the material. The bridge 200 is constructed from the same material as that of the boat fender 10 . A rope 190 is then capable of being inserted through the recessed line holder 180 as shown in the figure.
In FIG. 6, yet another embodiment of the present invention is illustrated. Here, the boat fender 300 has a recessed line holder 380 that includes a bridge 320 formed as a solid mass. The boat fender 300 has a hollow chamber 300 in order to allow the fender 300 making the fender inflatable. The bridge 320 is formed from the same material as that of the fender 300 .
Although the present invention has been shown and described with references to several preferred embodiments, it will be understood that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention. For example, the material of the present invention may be varied and selected according to the environment and usage envisioned for the particular boat and its environment. The fender may be inflatable or non-inflatable. In addition, the specific materials used to form the boat fender 10 may be selected from any material having sufficient resiliency and deformability, such as PVC (e.g., 30 oz. core mill or 42 oz. core mill), rubber, plastic, foam, etc. The recessed line holder may be constructed as a solid bridge, i.e., without a chamber, while the boat fender is made with an interior chamber thus rendering the boat fender as inflatable.
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A boat fender with a recessed line holder to permit an individual to adjust the positioning of the boat fender to a desired length. The recessed line holder is flush with the outer surface of the boat fender to create a smooth outer surface. The recessed line holder has a bridge under which a rope is inserted through a passage. The rope may then be tied off or secured to another fender.
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CROSS REFERENCE TO RELATED APPLICATIONS
More than one reissue application has been filed for the reissue of U.S. Pat. No. 6 , 320 , 574 . The reissue applications are application Ser. No. 10 / 720 , 001 ( the present application ), ( Ser. No. 11 / 408 , 528 ) and ( Ser. No. 11 / 408 , 669 ) all of which are divisional reissues of U.S. Pat. No. 6 , 320 , 574 .
RELATED APPLICATIONS
The present application is related to co-pending U.S. Patent Application entitled, “A Method and Apparatus for Upscaling an Image”, Filed Concurrently with the present application, Serial Number UNASSIGNED, Attorney Docket Number: PRDN-0001, and is incorporated in its entirety herewith.
The present application is also related to and is a continuation of application Ser. No. 08/803,824 filed Feb. 24, 1997, now U.S. Pat. No. 5,796,392, entitled, “Method and Apparatus for Clock Recovery in a Digital Display Unit.”
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to graphics system, and more specifically to a method and apparatus for recovering a clock signal associated with an analog display data received in a digital display unit (e.g., flat-panel monitor) of a graphics system.
2. Related Art
Digital display units are often used to display images. A flat-panel monitor generally used in lap-top computers is an example of such a digital display unit. A flat-panel monitor typically receives a source image from a graphics controller circuit and displays the source image. Flat-monitors which are being increasingly deployed with desk-top computers is another example of such a digital display unit. The source image is usually received in the form of analog data such as RGB signals well-known in the art.
Digital display devices often need to convert the received analog data into a sequence of pixel data. The need for such a conversion can be appreciated by understanding the general layout of a typical digital display device, which is explained below.
Digital display devices generally include a display screen including a number of horizontal lines. FIG. 1A is a block diagram illustrating an example display screen 100 . Each horizontal line (shown as 101 through 106 ), in turn, is divided into several discrete points, commonly referred to as pixels. Pixels in the same relative position within a horizontal line may be viewed as forming a vertical lien (shown as dotted line 108 ).
The number of horizontal and vertical lines defines the resolution of the corresponding digital display device. Resolutions of typical screens available in the market place include 640×480, 1024×768 etc. At least for the desk-top and lap-top applications, there is a demand for increasingly bigger size display screens. Accordingly, the number of horizontal display lines and the number of pixels within each horizontal line has also been generally increasing.
Thus, to display a source image, the source image is divided into a number of points and each point is displayed on a pixel. Each point may be represented as a pixel data element. Display signals for each pixel in display 100 may be generated using the corresponding display data element. However, as noted earlier, the source image may be received in the form of an analog signal. Thus, the analog data needs to be converted into pixel data for display on a digital display screen.
It is helpful to understand the typical format of the analog data to appreciate the usual conversion process. Generally, each source image is transmitted as a sequence of frames, with each frame including a number of horizontal scan lines. Image is generated on display screen 100 by displaying these successive frames.
Usually, a time reference signal is provided in parallel to divide the analog signal into horizontal scan lines and frames. In the VGA/SVGA environments known in the art, the reference signals include VSYNC and HSYNC. The VSYNC signal indicates the beginning of a frame and the HSYNC signal indicates the beginning of a next source scan line. The relationship between HSYNC and the analog signal data is illustrated further with reference to FIG. 1 B.
Signal 150 of FIG. 1B represents an analog display data signal in time domain. Analog signal 150 represents a display image to be generated on display screen 100 . The display signal portions 103 B, 104 B, 105 B etc. represent display data on corresponding horizontal lines 103 A, 104 B, and 105 B respectively. The portions shown as straight lines correspond to a ‘retrace’ period, which signifies the transition to a next horizontal line.
Such transitions are typically indicated by another signal (e.g., HSYNC signal in computer displays). Pulses 103 B, 104 B, and 105 B represent such transitions. Thus, after a transition, the display portion of the signal may be sampled a number of times. The exact number may be proportional to the number of pixels on each horizontal line on display screen 100 . Each display portion is generally sampled the same number of times to generate samples for each pixel.
Thus, to convert the source image received in analog signal form to pixel data suitable for display on a digital display device, each horizontal scan line is converted to a number of pixel data. For such a conversion, each horizontal scan line of analog data is sampled a predetermined number of times. The sampled value is represented as a number, which constitutes a pixel data element.
Each horizontal scan line is typically sampled using a sampling clock signal. That is, the horizontal scan line is usually sampled during each cycle of the sampling clock. Accordingly, the sampling clock is designed to have a frequency such that the display portion of each horizontal scan line is sampled a desired number of times. The desired number can correspond to the number of pixels on each horizontal display line of the display screen. However, the desired number can be different that the number of pixels on each horizontal display line.
Using the sampling scheme described above, each horizontal scan line of a source frame is represented as a number of pixel data. It will be readily appreciated that the relative position of source image points needs to be properly maintained when displaying the source image. Otherwise, some of the lines will appear skewed in relation to the other on the display screen.
To maintain a proper relative position of the source image pixels, the sampling clock may need to be synchronized with the reference signal. That is, assuming for purposes of explanation that HSYNC signal is used as a time reference, the beginning of sampling of analog data for a horizontal display line may need to be synchronized with HSYNC signal pulse. Once such a synchronization is achieved, the following pixels in the same horizontal lines may also be properly aligned with corresponding pixels in other lines.
Phase-locked loop (PLL) circuits implemented using analog components have conventionally been used to achieve such a synchronization. FIG. 2 is a block diagram of an example PLL circuit 200 which is implemented for such a synchronization. In addition, PLL circuit 200 generates the sampling clock signal also. PLL circuit 200 includes phase detector 210 , filter 220 , amplifier 230 , voltage controlled oscillator (VCO) 240 , and frequency divider 250 . Phase detector 210 compares a time reference (e.g., VSYNC) received on line 102 and sampling clock (more accurately, a signal having a predetermined fraction of the sampling signal) received on line 251 . The two signals are referred to as f 1 and f 2 for brevity.
Phase detector 210 provides on line 212 a signal having a difference of the frequencies of f 1 and f 2 . The signal on line 212 may also include several harmonics of the difference frequency. Filter 220 is generally designed as a low pass filter to eliminate undesirable components. When the frequencies f 1 and f 2 are close, but not equal, line 223 will carry a signal with the difference frequency. VCO 240 is designed to generate a signal with a predetermined frequency. However, the frequency is altered depending on the voltage level received on line 234 .
Amplifier 230 amplifies the signal on line 223 to provide a desired level of voltage on line 234 to modify the frequency of VCO 240 . The voltage level is generated so as to achieve a synchronization of the frequencies f 1 and f 2 . Frequency divider 250 divides the frequency of clock signal received on line 245 by a factor of n. By choosing an appropriate value of n, analog signal data for each horizontal source scan line can be sampled a desired number of times. The signal on line 245 can be used for such a sampling.
However, it is well known in the art, the reference frequency (HSYNC) can vary by a slight value from an average frequency during normal operating conditions. In addition, the reference frequency can drift over a prolonged period of time due to, for example, temperature changes in the circuits generating the analog source image data. Further, jitter may be present in both the reference signal and the clock signal generated by the analog PLL.
In general, it is desirable that the PLL of FIG. 2 track the long term drifts while eliminating the jitters. This may be achieved by having a PLL circuit with low bandwidth (e.g., 100 to 1000 Hz). However, such a low bandwidth generally requires a capacitor having a large size, which may be hard to integrate into a relatively small-sized integrated circuits.
Some prior approaches have placed the capacitor external to the integrated circuit, with the capacitor being coupled to the integrated circuit by pads. One problem with this approach is that noise is introduced into the analog PLL loop due to the external couplings. Analog PLLs are generally sensitive to such noises, leading to instability in the PLL loop. Without a low bandwidth in the loop, PLL 200 may be unable to track deviations in the reference signal closely, which may be unacceptable in some situations as explained below.
Deviations of about 5 to 20 nano-seconds in time reference period can be common in a typical graphics environment. These deviations are usually more problematic for larger size display screens. To illustrate this point with an example, a 640×480 size display screen has a pixel processing period (i.e., average time to display each pixel) of 40 nano-seconds, while a large 1280×1080 size monitor can have a pixel processing period of about 8-9 nano-seconds. A deviation of 20 nano-seconds may not have a perceptible impact on the display of a 640×480 screen due to the relatively larger pixel processing period, whereas the same amount of deviation can cause the display on the large monitor to be skewed by two pixels.
Such a skew between lines is generally perceptible for the human eye and the resulting display quality may be unacceptable. The display quality is further exacerbated if the number of such skews is larger. As is well known in the art, the display quality problems can be ameliorated by a circuit which can track the time reference signal more closely. Therefore, what is needed is a circuit which tracks the time reference signal closely.
SUMMARY OF THE INVENTION
The present invention is directed to a clock recovery circuit implemented in a digital display unit. The digital display unit receives an analog signal data and an associated time reference signal. Together, they represent an image to be displayed on a digital display screen usually provided in the digital display unit.
The clock recovery circuit provides a sampling clock based on the time reference signal. The sampling clock is used to sample the analog signal data, and the resulting pixel data is used to generate display signals on the display screen.
The clock recovery circuit includes a digital phase-locked loop (PLL). The bandwidth of the PLL can be instantaneously changed because of the digital implementation. In addition, the long term frequency and the temporary phase fluctuations are tracked using different control loops. As a result, considerable flexibility is available to a designer to track the time reference signal.
Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described with reference to the accompanying drawings, wherein:
FIG. 1A is a block diagram of an example display screen including several pixels arranged in horizontal rows;
FIG. 1B is a diagram of a signal shown in time domain illustrating an example time reference signal for an analog display data;
FIG. 2 is a block diagram of a conventional PLL circuit implemented using analog components;
FIG. 3 is a block diagram illustrating an embodiment of the clock recovery circuit of the present invention;
FIG. 4 is a block diagram of a digital PLL circuit illustrating independent loops for tracking frequency and phase;
FIG. 5 is a block diagram of an example analog filter to filter undesirable frequency components from the output of the digital PLL;
FIG. 6 is a block diagram of an example implementation of a digital PLL in one embodiment of the present invention;
FIG. 7 is a block diagram of an example graphics system implemented in accordance with the present invention; and
FIG. 8 is a block diagram of an example digital display unit in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
1. Overview and Discussion of the Invention
The present invention is described in the context of clock recovery circuit 300 ( FIG. 3 ) which includes digital PLL circuit 310 and analog filter 320 . The output of PLL circuit 310 is coupled to the input of analog filter 320 . PLL circuit 310 is implemented using digital components and signals.
In operation, PLL circuit 310 receives as input a time reference 301 and generates output signal 312 . While generating the output signal, PLL signal 310 attempts to synchronize the output signal 312 with time reference. Analog filter 320 filters any undesirable spectral components in the output signal 312 and provides the filtered signal as input to PLL circuit on input 302 .
PLL circuit 310 is implemented using digital components and a designer is provided considerable flexibility to specify the degree or manner in which output signal 312 should track reference signal 301 . Due to such a flexibility, the bandwidth of PLL circuit 310 can be dynamically varied such that PLL circuit 310 can be made to adequately track reference signal 301 . Such a close tracking may prevent relative skewing among the display lines.
As PLL circuit 310 is implemented using digital components, the circuit can be implemented to have a narrow bandwidth loop. Conventional analog PLLs may require large capacitors to implement an equivalent circuit. As already explained in the background section, integration of large capacitors into a semiconductor integrated circuit may be problematic.
Analog filter 320 can be conventional and is implemented using analog components in a known way. The output signal of analog signal corresponds to the clock (e.g., sampling clock) synchronized with the time reference REF. The output signal is divided by K, where K may correspond to the number of samples taken per each horizontal source image line.
Before describing the invention in great detail, it is useful to describe an example environment in which the invention can be implemented. The details of implementation and operation of clock recovery circuit 300 are then explained in detail.
2. Example Environment
In a broad sense, the invention can be implemented in any graphics system having a digital display unit. Such systems include, without limitation, lap-top and desk-top personal computer systems (PCS), work-stations, special purpose computer systems, central purpose computer systems, and many others. The invention may be implemented in hardware, software, firmware, or combination of the like. One or more embodiments which can use the clock recovery circuit of the present invention is described in the co-pending application entitled, “A Method and Apparatus for Upscaling an Image”, which is referred to in the section above entitled “Related Applications.”
FIG. 7 is a block diagram of computer system 700 in which the present invention can be implemented. Computer system 700 is only an example of a graphics system in which the present invention can be implemented. Computer system 700 includes central processing unit (CPU) 710 , random access memory (RAM) 720 , one or more peripherals 730 , graphics controller 760 , and digital display unit 770 . All these components communicate over bus 750 , which can in reality include several physical buses connected by appropriate interfaces.
Graphics controller 760 generates analog image data and a corresponding reference signal, and provides both to digital display unit 200 . The analog image data can be generated, for example, based on pixel data received from CPU 710 or from an external encoder (not shown). In one embodiment, the analog image data is provided in RGB format and the reference signal includes the VSYNC and HSYNC signals well known in the art and explained above. However, it should be understood that the present invention can be implemented with analog image data and/or reference signals in other formats. For example, analog image data can include video signal data also with a corresponding time reference signal.
Digital display unit 770 can include a display screen having pixels as explained with reference to FIG. 1 A. Digital display unit 770 includes a clock recovery circuit in accordance with the present invention. Using the clock recovery circuit, digital display unit 770 samples the analog signal data. The manner in which analog signal data is sampled if a sampling clock is provided to generate pixel data is well known in the art. Due to the clock recovery circuit of the present invention, digital display unit 770 may display an image corresponding to the analog signal data without a relative skewing of the lines.
CPU 710 , RAM 720 and peripherals 730 are conventional in one embodiment of the present invention. CPU 710 can be, for example, a processor such as a Pentium Processor available from Intel Corporation. RAM 720 represents the system/main memory for storing instructions and data. The instructions and data may be read from a peripheral device such a hard-disk. CPU 710 executes the instructions using the data to provide various functions. As a part of executing the instructions, CPU 710 may send commands to graphics controller 710 , which generates analog display signal data in a known way. The manner in which an example embodiment of digital display unit 770 displays the image corresponding to the analog display signal will be explained in further detail below.
3. Example Embodiment of Digital Display Unit 770 of the Present Invention
In one embodiment, digital display unit 770 is implemented to operate with a computer system. Digital display unit 770 can be in the form of a flat-panel monitor used in lap-top (note-book computers), a flat-monitor used in desk-top computers and workstations, among other forms. However, it will be apparent to one skilled in the relevant arts how to implement a digital display unit for other graphics system environments such as flat monitor television systems by reading the description provided herein.
FIG. 8 is a block diagram of digital display unit 770 including analog-to-digital converter (ADC) 810 , upscaler 820 , panel interface 830 , clock generator circuit 850 , and display screen 100 . The output line of ADC 810 is coupled to the input line of upscaler 820 . The output line of upscaler 82 is coupled to panel interface 831 . The output of panel interface is coupled to display screen 100 . Clock generator circuit 850 is coupled to ADC 810 , upscaler 820 , panel interface 830 .
In operation, ADC 810 receives analog signal data on line 801 and a sampling clock signal on line 851 . ADC 810 is conventional and samples the analog signal data according to the sampling clock signal. ADC 810 provides the pixel data on line 812 to upscaler 820 .
Upscaler 820 uses the pixel data received on line 812 to optionally upscale the image represented by the pixel data. The image may be upscaled, for example, due to the lager size of display screen 100 . An embodiment of upscaler 820 is described in co-pending application entitled, “A Method and Apparatus for Upscaling an Image”, which is referred to above in the section entitled “Related Applications.” In the co-pending application, upscaler 820 may be described as including the clock generation circuit 850 also.
Clock generator 802 generates the clock signals to ADC 810 , upscaler 820 and panel interface 830 . The individual clock signals may have different frequencies depending on the overall design. One or more the individual clock signals may be synchronized with time reference signal 802 by using the clock recovery circuit of the present invention. The manner in which different frequencies may be computed in one embodiment is also described in the co-pending application entitled, “A method and apparatus for upscaling an image.”
In one embodiment, time reference signal 802 may correspond to HSYNC signal. In another embodiment, time reference signal 802 may correspond to VSYNC signal. However, it should be understood that time reference signal 802 may correspond to any other signal (including a combination of HSYNC and VSYNC) as suited in the specific environment.
Display screen 100 is explained in detail above. Display screen 100 may be implemented using any digital screen technologies such as active/passive liquid crystal display (LCD) technologies. Panel interface 830 is designed to generate display signals to display image on display screen 100 . Panel interface 830 can be implemented in a known way to generate display signals to display screen 100 from the pixel data received from upscaler 820 .
The manner in which the clock recovery circuit synchronizes (or attempts to synchronize) the generated clock with the time reference will now be explained in detail. Specifically, PLL circuit 310 will be explained first. Then, analog filter 320 will be explained. For purpose of illustration, the time reference will be assumed to include a HSYNC signal. However, the present invention can be practiced with other types of reference signals as well.
4. Overview of Digital PLL Circuit of the Present Invention
FIG. 4 is a block diagram illustrating internal blocks of an example embodiment of digital PLL circuit 310 . PLL circuit 310 includes phase and frequency detector (PFD) 410 , frequency correction logic 420 , phase correction logic 430 , adders 440 and 450 , DTO 460 and DAC 470 . Phase correction logic 430 and frequency correction logic 420 are connected to the output of PFD 410 . First adder 440 is coupled to the output of frequency correction logic 420 . The output of first adder is coupled to second adder 450 . Second adder is also coupled to phase correction logic 430 . The output of second adder 450 is coupled to DTO 460 . The output of DTO is in turn connected to digital to analog converter 470 .
In operation, PFD 410 compares the phase and frequency of time reference (HSYNC) signal and feedback signal. PFD 410 is conventional and generates signals on EARLY and LATE lines depending on whether reference signal lags or leads the feedback signal. In one embodiment, a pulse is generated according to the lead or lag and the duration of the pulse is proportional to the amount of lead or lag.
The resynchronization process is achieved by having two separate blocks for correcting long term frequency drifts and phase jitters in the reference signal. By having two separate blocks, the designer may have more control over the resynchronization process.
In general, frequency correction logic 420 is designed to correct the long term frequency drifts in the reference signal. The frequency drifts generally correspond to a change in the reference frequency, typically in the range of few hertz. The drifts can be a result of, for example, temperature fluctuations in the source system generating the source image. Frequency correction logic 420 can be advantageously designed to track the reference signal over a prolonged period.
Adder 440 adds (subtracts) the frequency correction number provided by frequency correction logic 430 to Pnom frequency. Pnom corresponds to an expected frequency of the sampling clock and is used during the frequency acquisition phase. Frequency acquisition phase refers to a time duration during which the PLL loop is stabilizing and locking with the frequency of the reference signal. By providing the Pnom signal, the frequency acquisition period can be decreased.
However, digital PLL 310 can operate without Pnom signal. In this case, the frequency acquisition can take an extended period of time. After the frequency acquisition period is complete, Pnom may not be used. Phase correction logic 430 tracks phase fluctuations in the time reference. The output of phase correction logic 430 represents the degree (or amount) of phase by which the clock signal being generated should be corrected due to the phase difference between time reference signal and feedback signal.
The output of adder 440 represents the current frequency of the loop. The outputs of phase correction logic 420 and adder 440 are added using adder 450 . Thus, the output of adder 450 represents the total of Pnom, frequency correction provided by frequency correction logic 420 , and phase correction provided by phase correction logic 430 . This total represents how far the phase in DTO 460 is advanced per DTO clock cycle. This total can change during each reference clock cycle.
DTO 460 is conventional and is also known as a phase accumulator. DTO 460 generates as an output a ramp signal having a fundamental frequency and other undesirable spectral components. The fundamental frequency represents the frequency of the clock which is synchronized with the time reference signal. The spectral frequencies are undesirable as they may contribute to clock jitter. Accordingly, these spectral frequencies are eliminated using the analog filter 320 . DAC 470 converts the digital output of DTO into an analog form suited for processing by analog filter. Analog filter 320 is explained in further detail below. Before describing analog filter 320 in detail, an implementation of digital PLL circuit 310 is explained first.
5. An Implementation of Digital PLL
From the overview provided above, several alternative embodiments of digital PLL can be implemented without departing from the scope and spirit of the present invention. One of such embodiments will now be described with reference to FIG. 6 .
FIG. 6 is a block diagram illustrating the design and operation of an example implementation of digital PLL circuit 310 . PLL circuit 310 includes several components and signals interconnecting the components. Each component and signal will be explained in further detail below. Broadly, PLL circuit 310 will be described in three separate sections: (1) phase comparison, (2) frequency correction, and (3) phase correction.
As to phase comparison, PFD 603 has two output signal lines early 604 and late 605 indicating whether the feedback signal (FBACK) is early or late in phase in relation to time reference signal REF. In one embodiment, PFD 603 generates a pulse on early 604 , with the pulse having a duration which is proportional to the phase by which FBACK signal is early in comparison to REF signal. The pulse duration is measured in number of reference clock periods, where reference clock refers to a clock of which PLL circuit 310 operates. The pulses on early signal 604 and late signal 605 will be generally referred to as an error pulse. Late signal 605 is similarly explained.
PFD 603 stops comparing REF and FBACK signal when STOP signal is asserted. When the comparison is stopped, both LATE and EARLY signals are unasserted. Charge/discharge control 650 causes STOP signal to be asserted when the phase correction integrator can overflow. Comparison signal limiter 610 causes STOP signal to be asserted when the phase difference exceeds a predetermined number.
As to the frequency correction, frequency correction control 620 , multiplexor 630 , adder 627 and flip-flops 625 operate to provide the frequency correction. When PLL circuit is initialized (e.g., during the beginning of phase acquisition) as indicated by INIT signal, frequency correction control 620 causes multiplexor 630 to select as output the value on input having number 2. At the same time, A/S (Add/Subtract) signal is asserted to low, causing adder 627 to be set to a zero value by subtracting current accumulator value from itself.
Frequency correction control 620 then causes multiplexor 630 to select the Pnom value. Pnom corresponds to an expected frequency of the sampling block being generated. Accordingly, the frequency acquisition period is reduced to a few cycles assuming that the REF signal has a frequency which is in slight deviation from the expected frequency. Without Pnom, frequency acquisition may take several cycles.
After frequency acquisition, frequency correction control 620 causes Fdp value to be selected by multiplexor 630 . The Fdp value is added/subtracted during each reference clock cycle there is the error pulse. Addition of the Fdp value causes the clock frequency to be increased and subtraction causes the clock frequency to be decreased.
Fdp value is provided from a register. The Fdp value represents the loop bandwidth. A higher value of Fdp implies that the PLL 310 will respond faster to changes and lower value implies that the PLL 310 will be more stable. However, as the Fdp value can be changed instantaneously (i.e., within a reference clock cycle) by setting the register, the loop bandwidth can also be changed instantaneously.
Accordingly, a designer of the digital PLL 310 is given considerable flexibility to change the loop bandwidth depending on the specific situation. For example, during phase acquisition loop, Fdp value can be set fairly high, and it can be set to a low value once the loop stabilizes. In addition, Fdp can be based on adaptive schemes which base individual Fdp values on the historical values of phase corrections. The manner in which Fdp value is set in one embodiment will be explained below. Frequency correction control 620 enables FC-CE signal only during the length of the error pulse. The output of flip-flop 625 represents the current average frequency of the clock being generated.
As to the phase correction, phase correction is broadly explained first. Charge/discharge control 650 along with the associated circuitry may be viewed as a leaky integrator, but implemented in digital domain. The integrator is charged to a level using the PPDP value. The level to which it is charged depends on the duration of the error pulse length. After it is charged, the integrator is slowly discharged using the NPDP value. The NPDP value is smaller in value in comparison to PPDP value and thus the discharge occurs during an extended period of time. The phase correction is performed during the discharge cycles. The manner in which charging and discharging are performed is explained in further detail below. The manner in which NPDP and PPDP values are computed in one embodiment will then be explained.
Charge/discharge control 650 , multiplexor 655 , adder 660 , and flip-flop 665 together determine the charge on the integrator. It should be noted that flip-flop 665 (and other flip-flops described here) in reality includes several flip-flops, with each flip-flop storing one bit. The value in adder 660 is cleared at the beginning of each time reference cycle (e.g., when a HSYNC pulse is received). The PPDP value is added to adder 660 during each reference cycle (i.e., the internal clock of PLL) the error pulse is present. If the result of the addition exceeds a predetermined threshold, the integrator is determined to have overflown, and the integrator overflow detector 673 causes the STOP signal coupled to PFD 603 be asserted. When the end of the error pulse is encountered, flip-flop 665 stores a value indicative of the charge on the integrator.
After the charging is complete, the discharge phase is begun. Phase correction of the clock is performed during the discharge phase. During the discharge phase, charge/discharge control 650 causes NPDP value subtracted iteratively from accumulator 660 during each reference clock cycle. During each discharge clock cycle, inactive REMINDER signal causes NPDP value to be selected by multiplexor 652 . Also, phase correction control 675 provides PCORR signal so as to gate the output of AND logic 677 to adder 680 . Otherwise, PCORR signal is set at low signal level (logical value of 0) to set the output of AND logic 677 to zero. Phase correction control 675 asserts the A/S input of adder 680 to cause the output of adder 677 to be added or subtracted. The value is added if the REF signal is ahead of FBACK signal and subtracted otherwise.
As NPDP value is subtracted during each reference clock cycle, it is possible that the result after the subtraction may be a negative number. In this case, the clock signal has been over corrected. Accordingly, sign and zero crossing detector 670 detects that the phase has been over corrected and causes charge/discharge control 650 to take corrective action. The negative number is stored in flip-flop 674 .
Charge/discharge control 650 asserts REMINDER signal to 1 to cause multiplexor 652 to select the value stored in flip-flop 674 . The selected value to provided to added 680 , which corrects the overcorrection. Phase correction control 675 switches the value on the A/S input to adder 680 . That is, if previously the a 0 value is provided, a value of 1 is provided when forwarding the overcorrection parameter.
The operation of DTO has been explained above with reference to FIG. 4 and will not be repeated here in the interest of conciseness. Briefly stated, DTO 460 generates as an output a ramp signal representing phase of a fundamental frequency and other spectral components such as images resulting from the digital sampling. The fundamental frequency represents the frequency of the clock which is synchronized with the time reference signal. The spectral components are undesirable as they may contribute to clock jitter. The remaining portion of the circuit is designed to eliminate these other frequencies while preserving the fundamental frequency.
LUT 690 is conventional and translates the phase output of DTO 460 to an amplitude value. The phase value may be converted to either a sine wave or a triangle as is also known well in the art. DAC 695 converts the output of LUT 690 to an analog signal for suitable processing by analog filter 320 . An embodiment of analog filter 320 is explained later.
It is again noted, that the above description of FIG. 6 is merely an example implementation and it will be apparent to one skilled in the art to implement various modifications without departing from the scope and the spirit of the present invention. In the above description, Pnom, NPDP and PPDP values have been described to be used. One example way of computing these parameters is explained.
6. Computation of the loop parameters
Pnom can be calculated based on the number of reference clocks in the hor line (Hor_Rcount):
Hor_Rcount−Th/Trclk (1)
where Trclk represents the clock period of reference clock and Th represents the horizontal period (time between two successive Hsync pulses).
Pnom=srs_htotal*Qdto/Hor_Rcount (2)
Here, Qdto is DTO module, (i.e., 2**n, where n is the number of bits in DTO). It should be noted that Pnom isn't dependent on locking scheme. That is, the clock signal can be locked on HSYNC, VSYNC, or the like.
Positive slope (Charging) parameter for phase correction loop is derived from Pnom. It is also independent of the locking scheme. Kpdp controls damping of phase correction loop. For optimal tracking it may be set to 3 or 3.
Ppdp=Pnom/Kpdp (3)
Negative slope parameter (discharging) is derived from Ppdp. NPDP is usually close to Ppdp if loop is unlocked and several times smaller (8 . . . 16) if loop is locked (to minimize phase jumps).
Npdp=Ppdp/Knpdp (4)
Knpdp=2 . . . 16
Frequency correction parameter is dependent on locking scheme. It means amount of frequency adjustment per one Rclk phase tracking error.
If the FBACK signal is locked on HSYNC pulses as a time reference
Fdp=Pnom/(Kfdp*Vdiv*Hor_Rcount) (5a)
If FBACK signal is locked in Vsync pulses as a time reference
Fdp=Pnom/(Kfdp*Vtotal*Hor_Rcount) (5b)
Here Vdiv is vertical Hsync divider (1 . . . n). If Vdiv is 1, every Hsync is used for comparison. If Vdiv is 2, every other Hsync is used, etc. Vtotal is number of lines in the source frame if VSYNC locking is used.
7. Analog Filter 320
As noted above, analog filter 320 is designed to preserve the fundamental frequency generated by DTO while eliminating the other frequencies. Analog filter 320 can be implemented using active or passive filters or using a phase-locked loop as is well-known in the art. An example embodiment of analog filter 320 is illustrated with reference to FIG. 5 .
Analog filter 320 is conventional and includes a DAC reconstruction filter 510 . Schmidt trigger 520 slices the sine-wave in a known way to convert the sine-wave into digital signal (two level quantization). The PLL loop comprising PFD 530 , charge pump 540 , loop filter 550 , VCO 560 , and divider 580 is designed to eliminate all the undesirable frequencies, while preserving the fundamental frequency. The value of N in divider 580 is kept relatively small (at or below 8). VCO 560 may be designed to generate sampling clock signal, which can be used to sample the analog signal data. Dividers 570 and 580 may be used to shift the Vco frequency into the operating range of Vco 560 .
Thus, the output of analog filter 320 includes filtered signal with well-suppressed spurious spectral components.
16. Conclusion
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A clock recovery circuit in a digital display unit for recovering a time reference signal associated with analog display data. The clock recovery circuit includes a phase-locked loop (PLL) implemented in digital domain and an analog filter to eliminate any undesirable frequencies from the output signal of the PLL. The PLL includes independent control loops to track long term frequency drifts of the time reference signal and the transient phase differences respectively. By providing such independent control loops, the generated clock can be better synchronized with the time reference signal.A system and method for displaying an analog source image by a digital display unit. A converter circuit generates a plurality of digital source image elements from an analog source image based upon a sampling clock signal synchronized with a time reference signal associated with the analog source image. A scaler unit receives the digital source image elements in accordance with a first clock signal, scales the source image elements independently in both vertical and horizontal directions to form destination image elements, and provides the destination image elements to the display unit in accordance with a second clock signal. The first clock signal and the second clock signal are arranged such that a source frame rate and a destination frame rate are substantially equal.
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BACKGROUND OF THE INVENTION
The invention relates to a distributed threshold voltage field effect transistor (DTV-FET) wherein a first field effect transistor (FET) and a second FET are coupled in series and a voltage is applied to the gate of the first FET.
A low off-current is a very important factor for amorphous-silicon field-effect transistors (a-Si FETs) used in active matrices. This is because a high off-current causes various problems in FET-addressed liquid-crystal displays, such a degradation of optical image quality.
The Distributed Threshold Voltage Field Effect Transistor (DTV-FET) was recently proposed (Uchida and Matsumura, Jpn. J Appl Phys 27 L2379 (1988)) under these circumstances. It incorporates a structured channel of amorphous-silicon (a-Si:H) or poly-silicon such that the channel has a changing local threshold voltage Vt from source to drain. The effect of this is to increase the separation (in gate voltage terms) between electron conduction and hole conduction. This increased separation is called the DTV-FET effect. The advantage of this effect is that it allows a larger choice of voltages ranges that can be used, giving greater design freedom. This freedom can be used for instance to counter a non-uniform distribution of transistor characteristics within an active matrix, or to increase the choice of liquid crystals that can be used. Also, the reduction in off current that occurs as a result of the DTV-FET effect leads to an improved performance of active matrix LCD displays.
The simplest way to realize the DTV-FET is, as shown in FIG. 8, to externally connect two normal transistors in series and apply the gate voltage Vg plus a constant offset voltage Vos to the transistor on the drain side.
A second method to fabricate the DTV-FET is, as shown in FIG. 9a, to dope part of the channel. The channel region denoted "n - a-Si" is nominally undoped, but the region denoted "n a-Si" is moderately doped. At moderate doping levels, the effect of the doping is to shift the characteristics (in gate voltage terms) without altering their shape. Hence the threshold voltage distribution is a step function along the channel. This then results in the DTV-FET effect.
FIG. 9b shows an equivalent circuit of the DTV-FET shown in FIG. 9a which is formed by connecting two uniform FETs, Q s and Q d , in series. FIG. 9c shows one example of off-characteristics of DTV-FET shown in FIG. 9a wherein the dotted curves are those of the individual uniform FETs.
As outlined above, the DTV-FET structures proposed so far achieve the DTV-FET effect either by using an extra offset voltage as DTV-FET in FIG. 8 or by doping part of the channel as one in FIG. 9a.
The disadvantage of the first method is that it requires application of at least a third voltage to what is in effect a four terminal device. This means that in the circuit in which the transistor is incorporated (for example, the liquid crystal display's active matrix) additional scan lines have to be used to lead the extra voltage to the transistor. The fabrication of these additional scan lines increases production cost an their presence increases the chance of display failure due to, for example, cross-over shorts. Furthermore, the area occupied by the additional scan lines reduces the display's aperture ratio.
The second method of creating the DTV-FET by doping part of the channel avoids the need for an extra voltage and the problem of the additional scan lines. However, the amplitude of the distribution in VT and therefore the magnitude of the DTV-FET effect, is limited by the relatively small shift in threshold voltage that can be obtained by doping (see, for example, Uchida and Matsumura, MRS Symp Proc. 149 247 (1989).
SUMMARY OF THE INVENTION
It is one of the objects of the invention to provide a new DTV-FET with a substantial DTV-FET effect which needs neither an externally applied additional voltage nor the doping method for its production.
To achieve this object, the DTV-FET according to the invention is characterized in that:
(a) the voltage is a pulse voltage whose on-time and off-time are respectively t on and t off ,
(b) a first capacitor with capacitance C 1 and a second capacitor with capacitance C 2 are coupled in series between the junction point of the first field effect transistor and the second field effect transistor and the gate of the first field effect transistor,
(c) a non-linear resistor whose resistivity is R on during t on and R off during t off is coupled between respective gates of the first field effect transistor and the second field effect transistor,
(d) the junction point of the first capacitor and the second capacitor is coupled to the gate of the second field effect transistor,
(e) time constant R on (C 1 +C 2 ) is enough smaller than t on , and
(f) time constant R off (C 1 +C 2 ) is enough larger than t off , whereby a biased voltage is formed on the gate of the second field effect transistor during t off .
The invention is based on the following recognition. In the applications mentioned, the transistors always operate under pulsed driving conditions. It is therefore possible to use RC circuits to create temporary offset voltages between two or more gates, which will be explained with FIGS. 4a and 4b. A pulsed wave form as shown in FIG. 4b is applied at node 1 and appears unchanged at node 2. If the time constant of RC circuit 3 is of the same order as either t on or t off , a time dependent voltage will appear between node 2 and node 4. Furthermore, by using a non-linear device such as, for example, a diode for the resistance in the RC circuit, these offset voltages can be made to depend on whether the device is in an "on" or in an "off" stage. For example, if R is low during t on but high during t off , the offset voltage between node 2 and 4 will exist only during t off . Therefore the DTV-FET can be obtained by connecting node 2 to the gate of a first field effect transistor which constitutes a main gate and node 4 to the gate of a second field effect transistor which constitutes a transient gate.
When a symmetrical DTV-FET is required in which the DTV-field effect transistor effect is obtained under both positive and negative drain voltage, the following two DTV-FETs are necessary. One of them is characterized in that another field effect transistor whose gate is coupled to the second field effect transistor is coupled to the first field effect transistor in series.
The other one of the symmetrical DTV-FETs is characterized in that another field effect transistor whose gate is coupled to the first field effect transistor is coupled to the second field effect transistor in series.
It is desirable that the non-linear resistor is a diode in the DTV-FET.
The DTV-FET which is suitable especially for the LCD matrix is characterized by comprising:
(a) first gate electrode provided on a substrate,
(b) first insulator layer partly covering the gate electrode,
(c) second gate electrode provided on the first insulator,
(d) second insulator layer covering the first gate electrode and the second gate electrode except a window provided on the second gate electrode,
(e) semiconductor layer provided on the second insulator layer,
(f) two contacts provided on one part of the semiconductor layer, and
(g) two contacts provided on the other part of the second insulator layer, one of which is connected between the semiconductor layer and the second gate electrode, and the other of which is connected between the semiconductor layer and the first gate electrode.
The DTV-FET whose structure is simple is characterized by comprising:
(a) gate electrode provided on a substrate,
(b) first insulator partly covering the gate electrode,
(c) first semiconductor layer covering both the first insulator and part of the gate electrode,
(d) second insulator provided on the first semiconductor layer transient gate,
(e) second semiconductor layer whose conductive type of the channel is opposite to one of the first semiconductor layer, and
(f) two contacts provided on the second semiconductor layer.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described in greater detail with reference to several embodiments and the drawing, in which:
FIG. 1 shows the DTV-FET of the present invention;
FIG. 2 shows wave forms of Vg and Vg' in the DTV-FET of FIG. 1;
FIG. 3 shows source-drain current as function of V off for the DTV-FET in FIG. 1;
FIG. 4a, 4b are drawings to explain the basic idea of the present invention;
FIG. 5a and 5b show modified embodiments of the DTV-FET in FIG. 1;
FIG. 6 shows the structure of the DTV-FET to realize the circuit in FIG. 1;
FIG. 7 shows another structure of the DTV-FET in FIG. 1;
FIG. 8 shows the first conventional way to realize a DTV-FET;
FIG. 9a shows the second conventional way to realize a DTV-FET;
FIG. 9b is an equivalent circuit of the DTV-FET shown in FIG. 9a;
FIG. 9c shows off-characteristics of the DTV-FET shown in FIG. 9a;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the DTV-FET of the present invention based on the above-mentioned recognition. The main gate potential Vg at node 5 is a pulsed drive form as illustrated in FIG. 2. In this wave form it is assumed that the circuit is required to work in an n-channel mode, i.e. the on voltage V on is larger than the off voltage V off . A similar description can also be made using the reverse condition of p-channel transistors and an inverted gate voltage wave form.
The potential illustrated in the upper waveform of FIG. 2 is applied directly to a main gate, the gate of transistor 6. The gate potential Vg' of transistor 7, a transient gate potential, is determined by the RC circuit of capacitors 8 and 9 and non-linear resistor 10. This non-linear resistor has the property that when node 30 is negative with respect to node 5, its resistivity has a low value R on , but when the voltage difference across non-linear resistor 10 is positive, its resistivity has a large value R off . The non-linear resistor 10 can be fabricated by a diode, a transistor, etc.
In the present invention, the values of C 1 , C 2 , R on and R off are chosen in relation to t on and t off such that:
R.sub.on (C.sub.1 +C.sub.2)<<t.sub.on (1)
R.sub.off (C.sub.1 +C.sub.2)>>t.sub.off (2)
However, for easier understanding of the operation of DTV-FET in FIG. 1, hereat, the following condition is employed for explanation:
R.sub.on (C.sub.1 +C.sub.2)≈t.sub.on
R.sub.off (C.sub.1 +C.sub.2)≈t.sub.off.
Before time t 1 potential Vg' is equal to main gate potential V off . At time t 1 main gate potential Vg switches to V on and, due to capacitors 8 and 9, Vg' switches to V off +C 1 /(C 1 +C 2 ) (V on -V off ). The resistivity of non-linear resistor 10 is low (R on ) and potential Vg' quickly rises to V on with a time constant R on (C 1 +C 2 ). By time t 2 , Vg' is once again equal to the potential on the main gate. The main gate potential then switches off, Vg' drops to V on -C 1 /(C 1 +C 2 ) (V on -V off ), now the resistivity of the non-linear resistor becomes high (R off ) and potential Vg' decays to V off with a larger time constant R off (C 1 +C 2 ).
In the previous paragraph, RC time constants similar to t on and t off have been used, but if
R.sub.on (C.sub.1 +C.sub.2)<<t.sub.on
R.sub.off (C.sub.1 +C.sub.2)>>t.sub.off.
as proposed above, then
Vg'=V.sub.on during t=t.sub.on (3)
Vg'=V.sub.on -C.sub.1 /(C.sub.1 +C.sub.2)(V.sub.on -V.sub.off) .sub. during t=t.sub.off (4)
Indicated by the dashed line in FIG. 2, this condition results in a DTV-FET effect because the situation described is equivalent to having a step function in Vt during t off . In reality, during the off-time, when a negative gate potential is applied at node 5 in the circuit in FIG. 1, Vg' is always larger than Vg by Vos as shown by two full lines in the bottom of FIG. 2. This means that the circuit device of the present invention works as DTV-FET without additional voltage supply unlike the conventional one as shown in FIG. 8.
The DTV-FET effect of the circuit device in FIG. 1 is illustrated in FIG. 3. The full line (curve c) shows the current between source 11 and drain 12 during t off as a function of V off under the condition that R on =O and R off =inf.; capacitors 8 and 9 are equal, C 1 =C 2 ; drain voltage Vd=10 V and the gate voltage during the on-time V on =10 V.
For comparison, curve a shows the characteristic if the RC circuit is short circuited out, i.e. Vg'=Vg at all times. This curve a represents in effect the conventional (non DTV-FET) transistor. Curve b shows the characteristic if the gate of transistor 6 is also connected to Vg'. By comparing curves a and c in FIG. 3, the DTV-FET effect of the present invention can be seen clearly, i.e. the range over which the transistor is effectively off is substantially increased. This means that the DTV-FET of the present invention has wider range of off-state than the conventional DTV-FET shown in FIG. 9a which is manufactured by a doping method.
FIGS. 5a and 5b show modified embodiments of the DTV-FET of FIG. 1 which are essential if such device is to be applied to active matrix displays. As mentioned before, in active matrix addressing, operation under both negative and positive drain voltage is required, which needs a symmetrical DTV-FET. To achieve this, either a transient gate must also be created under the source contact, or a normal transistor placed at the drain contact. In FIG. 5a, an extra transistor 13 has been added on the left, the gate of this extra transistor is connected to the transient gate potential Vg'. In FIG. 5b, the extra transistor 13 is placed on the right and its gate connected to the gate potential Vg. For these circuits, the strict distinction between source and drain disappears and the circuits will show a DTV-FET effect for both a negative and a positive potential difference between contacts 14 and 15.
The circuit in FIG. 1 can, of course, be realized by using standard components like discrete FETs and capacitors. However, in the LCD active matrix, the area occupied by the different components and the extra fabrication steps required to provide interconnections between them will decrease the display aperture, increase production cost, and decrease yield.
In the following will be provided two structures to realize the DTV-FET in FIG. 1 which are suitable for the LCD active matrix. Shown in FIG. 6 is an example of the DTV-FET structure according to the present invention. On substrate 26 of, for example, glass, is provided gate electrode 16 of, for example Cr. This gate electrode 16 is partially covered by first insulator layer 17 of, for example SiNx, and partly covered by second insulator layer 19, also of, for example SiNx. The transient gate electrode 18 of, for example Mo, is provided on top of first insulator layer 17 and covered by second insulator layer 19 except for a window which has been provided to give electrical contact between transient gate electrode 18 and contact 21. On top of second insulator layer 19 is provided semiconductor layer 20 of, for example a-Si:H and contacts 21, 22, 23, 24 and 25 of, for example A1, are provided on semiconductor layer 20.
Transistor 6 in FIG. 1 is comprised in region T1 of gate electrode 16 as gate, second insulator layer 19 as gate dielectric, semiconductor layer 20 as active layer, and contacts 23 and 24 as source and drain respectively. The transistor 7 in FIG. 1 is comprised in region T2 of transient gate electrode 18 as gate, second insulator layer 19 as gate dielectric, semiconductor layer 20 as active layer and contacts 24 and 25 as source and drain respectively. Capacitor 8 in FIG. 1 is comprised in region T2 of gate electrode 16 as bottom plate, first insulator layer 17 as dielectric and transient gate electrode 18 as top plate. Finally capacitor 9 in FIG. 1 is comprised in region T2 of transient gate electrode 18 as bottom plate, second insulator layer 19 as dielectric and semiconductor layer 20 as a top capacitor plate.
The function of contact 24, which acts as drain for transistor 6 and as source for transistor 7, is to provide a connection between the regions of the active layer 20 in which the channels of transistors 6 and 7 are located and to bridge the region where the first insulator layer is not covered by transient gate 18. The length of contact 24 is determined by the length of this latter region and will be zero if this region does not exist.
During operation, potential Vg is applied to gate electrode 16, potential Vs to contact 23 and potential Vd to contact 25 as shown in FIG. 6.
In the DTV-FET in FIG. 6, non-linear resistor element 10 in FIG. 1 is provided by the transistor in region T3 which comprises gate electrode 16 as gate, second insulator layer 19 as gate dielectric, semiconductor layer 20 as active layer, source contact 21 and drain contact 22. Gate and drain of this transistor are electrically connected, and this transistor represents a low resistivity R on between gate electrode 16 and transient electrode 18 when the gate potential is at V on , and a high resistivity R off when the gate potential is at V off . More specifically, when, for instance, active layer 20 is used in an n-channel mode as would be the case for a-Si:H, then, during t on , when the potential of contact 21 is lower than the potential Vg of gate electrode 16 and contact 22, an electron accumulation layer will be formed in semiconductor layer 20 and the transistor will operate in pinch-off mode and have a low resistivity. However, when the voltage difference between contacts 21 and 22 is negative, no electron accumulation layer will be formed and a high resistivity condition exists, as required by the specification of non-linear resistor 10.
The transconductance function used to calculate the results in FIG. 3 was based on an inverted staggered amorphous silicon thin film transistors T 1 , T 2 , with a 2100 A thick silicon nitride gate insulator layers 17, 19, an active layer 20 thickness of 800 A and A1 source and drain contacts 21-25. The aspect ratio W/L was 10.
A second structure of the DTV-FET according to the present invention is shown in FIG. 7. As before, on substrate 26 of, for example, glass, is provided gate electrode 16 of, for example, Cr, which is partly covere by first insulator layer 17 of, for example SiNx.
The distinguishing feature of the structure of FIG. 7 with respect to the one illustrated in FIG. 6, is that transient gate 18 covers both first insulator layer 17 and part of the gate electrode 16. Furthermore, transient gate 18 is a semiconductor, for example p-type a Si:H, of the opposite conductive type of the conductive type of the channel in active layer 20, which is for example, n-channel conduction in a Si:H. Second insulator layer 19 of, for example, SiNx and active layer 20 are layered on top of transient gate 18.
Contacts 23 and 25 of, for example Al, which act as source and drain respectively, are provided on top of the active layer 20. As in the structure of FIG. 6, during operation, potential Vg is applied to gate electrode 16, potential Vs to contact 23 and potential Vd to contact 25.
All elements except the non-linear resistor provided in the structure illustrated in FIG. 7 are formed in similar way to the structure illustrated in FIG. 6. That is to say, transistor 6 is comprised in region T1 of the portion of the transient gate electrode 18 which lies directly on gate electrode 16 as gate, second insulator 19 as gate dielectric, semiconductor layer 20 as active layer, contact 23 as source and the middle of the active layer 20 as virtual drain. Transistor 7 is comprised in region T2 of the portion of transient gate electrode 18 sandwiched between the first and second insulator layers 17, 19 as gate, second insulator layer 19 as gate dielectric, semiconductor layer 20 as active layer, contact 25 as drain and the middle of active layer 20 as virtual source. Capacitor 8 is provided in region C1 shown in FIG. 7 by gate electrode 16 as bottom plate, first insulator layer 17 as dielectric and the portion of transient gate layer 18 sandwiched by the first and second insulator layers 17, 19, as a top plate. Capacitor 9 is, as shown in region C2 in FIG. 7, build up out of the same part of transient gate 18 as bottom plate, second insulator layer 19 as gate dielectric and finally active layer 20 as a top plate.
Non-linear resistor element 10 in FIG. 1, shown in NL in FIG. 7, is provided by transient gate layer 18 itself. The difference in R on and R off of this doped semiconductor layer derives from the difference in hole and electron conduction within this layer. When, for instance, the channel of the transistor in active layer 20 is of an electron enhancement type and the conductive type of the transient gate is therefore p-type, then during the on-time t on the gate potential Vg will be such that a positive potential difference exists between transient gate 18 and active layer 20. This potential difference results in an electron accumulation channel in the active layer as intended, but it also induces a hole accumulation in the transient gate. This hole accumulation causes a low resistance R on between the portion of the transient gate sandwiched between the first and second insulator layer in region T2 and the portion of the transient gate which lies directly on the main gate in region T1.
During the off-time t off , when the potential difference between active layer 20 and gate electrode is reversed, the positive charge of the accumulated holes flows quickly from transient gate 18 sandwiched between the two insulator layers 17, 19 on the right hand side, and the potential there drops to Vg'=C 1 /(C 1 +C 2 ) Vg (notation from FIG. 1 and Vs=Vd=0). However, after that, the resistivity of semiconductor layer 18 is determined by electron minority carrier conduction in the p-layer which will have a high value R off . Thus the resistivity of the transient gate layer 18 in FIG. 7 conforms to the specification of the non-linear resistor 10 in FIG. 1. It is understood that the p-layer must be sufficiently thin, such that complete majority carrier depletion can take place.
With reference to the structures in both FIGS. 6 and 7, it is noted that the elements building up capacitor 9 and transistor 7 are identical. Furthermore, it is recognized that because the top plate of capacitor 9 is formed by active layer 20, the top plate of capacitor 9 is not at a single potential but changes continuously between the potential of contact 25 on the right hand side, to the potential of contact 24 on the left hand side in the case of FIG. 6, and the potential of the middle of active layer 20 in the case of FIG. 7.
In the above structures the Al contacts are applied directly onto the semiconductor layer, however, in present a-Si:H TFT technology, n + -type doped semiconductor layers and layers of alternative metals like Cr are sometimes inserted between the a-Si:H semiconductor and the Al. Such added features and process steps are not precluded by this invention.
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A distributed threshold voltage TFT has a first FET and a second FET connected in series with the first point between the first and the second FET via a series circuit of a first capacitance and a second capacitance. The gate of the second FET is connected to the junction point between the first and the second capacitance and to the gate of the first FET via a non-linear resistance with a low R on and a high R off . Leakage currents can be kept very low in this DTV FET without an extra external voltage and/or without extra doping.
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BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to a process for producing a glycidyl ester of acrylic acid or methacrylic acid (hereinafter sometimes collectively referred to as "Glycidyl Methacrylate, etc.") which ester is widely used as a starting raw material for industrial use for resin modifiers, thermosetting coating materials, adhesives, textile treating agents, antistatic agents, ion exchange resins and the like.
2. Description of the Related Arts
In recent years, Glycidyl Methacrylate, etc. with a minimized content of chlorine have been required in the fields of coating materials, electronic materials, textile materials and the like from the viewpoints of coating characteristics, electrical characteristics, safety, etc.
Glycidyl Methacrylate, etc. have heretofore been produced generally by any of the following three processes.
(1) The process which comprises the steps of reacting acrylic acid or methacrylic acid (hereinafter sometimes collectively referred to as "Methacrylic Acid, etc.") with epichlorohydrin in the presence of a quaternary ammonium salt to produce a 3-chloro-2-hydroxypropyl ester of Methacrylic Acid, etc. and dehydrochlorinating the resultant ester with an alkali (refer to Japanese Patent Publication No. 34010/1971 and Japanese Patent Application Laid-Open No. 5713/1973).
(2) The process which comprises the steps of reacting Methacrylic Acid, etc. with epichlorohydrin in the presence of a quaternary ammonium salt to produce a 3-chloro-2-hydroxypropyl ester of Methacrylic Acid, etc. and subjecting the resultant ester to transesterification with an epoxy compound (refer to Japanese Patent Publication Nos. 9005/1966 and 10575/1978 and Japanese Patent Application Laid-Open No. 95216/1975).
(3) The process which comprises the steps of reacting Methacrylic acid, etc. with an alkali to produce an alkali metal salt of Methacrylic Acid, etc., subsequently reacting the resultant alkali metal salt with epichlorohydrin in the presence of a quaternary ammnonium salt and dehydrochlorinating the resulting reaction product (refer to Japanese Patent Publication Nos. 28762/1970 and 4006/1973 and Japanese Patent Application Laid-Open No. 39423/1973).
The above-mentioned processes (1) and (2) necessitate a troublesome step of treating the reaction liquid with an alkali hydroxide or like step in order to obtain Glycidyl Methacrylate, etc. in high yield and with minimized content of chlorine impurities such as a 3-chloro-2-hydroxypropyl ester of 1,3-dichloropropanol or 2,3-dichloropropanol and Methacrylic acid, etc.
On the other hand, the process (3) suffers the disadvantage of unfavorable economical efficiency in that there is a fear of causing polymerization of the alkali metal salt of Methacrylic Acid, etc. at the time of drying and so there is need for installing an expensive spray dryer or the like in order to achieve a high yield and for preparing-the aqueous solution of the alkali metal salt of Methacrylic Acid, etc. in a separate apparatus.
In order to solve such problem there is disclosed in Japanese Patent Publication Nos. 13470/1989 and 20152/1989 a process for producing a glycidyl ester of acrylic acid or methacrylic acid which comprises the steps of suspending a carbonate and/or bicarbonate of an alkali metal and Methacrylic Acid, etc. in an excess amount of epichlorohydrin to cause a neutralization reaction while air is blown thereinto; azeotropically distilling away outside the reaction system, the water formed by neutralization along with the epichlorohydrin to produce an alkali metal salt of Methacrylic Acid, etc.; subsequently adding a quaternary ammonium salt as a catalyst to the reaction system to react the alkali metal salt with the epichlorohydrin; adding water to the resulting reaction liquid after the completion of the reaction and washing the reaction liquid to separate the water layer from the organic layer; and subsequently distilling the organic layer. According to this process, it is possible to synthesize Glycidyl Methacrylate, etc. with ease in high yield.
However, in the case where the halogenated alkali and glycidol that are formed by the reaction are washed away with water, 1,3-dichloropropanol is formed in a large amount, which can not be separated from Glycidyl Methacrylate, etc. by means of distillation because of its boiling point being close to that of Glycidyl Methacrylate, etc. In addition, since a side reaction is brought about such as the formation of epichlorohydrin in the course of distillation, the Glycidyl Methacrylate, etc. to be formed as the objective product is made to contain high concentrations of epichlorohydrin and hydrolyzable chlorine, Moreover, the process suffers the drawback that the yield of Glycidyl Methacrylate, etc. is lowered by the dissolution of Glycidyl Methacrylate, etc. in the water layer and the hydrolysis of the same.
Even in the case of the alkali metal salt formed by the reaction being filtered off, impurities such as glycidol can not be removed in spite of the non-formation of 1,3-dichloropropanol and accordingly, both the resultant crude Glycidyl Methacrylate, etc. and the refined Glycidyl Methacrylate, etc. after the distillation are made to contain glycidol in a large amount. Such Glycidyl Methacrylate, etc. that contains glycidol in a large amount involves the problem that the degree of polymerization is not enhanced when it is subjected to radical polymerization, the preservation stability thereof is worsened, or the like, thereby causing deterioration of the performance when made into a coating material or resin. The above-mentioned problem necessitates an additional water washing step requiring a troublesome procedure for the purpose of removing the glycidol as disclosed in Japanese Patent Application Laid-Open No. 235980/1992, whereby the process is made industrially disadvantageous.
Further, the crude Glycidyl Methacrylate, etc. produced by any of the foregoing processes (1), (2) or (3), which is generally refined by distillation, also involves the problem that the side reactions take place in the course of distillation as represented by the reaction formulae (a), (b) and (c) (set forth hereinbelow) by the influence of the catalyst which can not be completely removed by filtration and water washing, and the by-produced epichlorohydrin, glycerol ester of methacrylic acid, glycidol and the like lower the purity and yield of the objective product. ##STR1##
In order to solve the aforesaid problems, there are proposed a method in which a heteropolyacid or an alkali salt thereof is added to the crude Glycidyl Methacrylate, etc., followed by distillatory separation (Japanese Patent Application Laid-Open No. 255273/1988); a method in which an alkali hydroxide in powder form is added to the crude Glycidyl Methacrylate, etc., followed by distillation (Japanese Patent Application Laid-Open No. 102217/1977); a method in which the reaction liquid is subjected to stripping with an oxygen-containing gas in the presence of quaternary ammonium salt, followed by distillation (Japanese Patent Application Laid-Open No. 187682/1992); and like methods.
The Glycidyl Methacrylate, etc. that are produced by the above-mentioned process usually contain about 300 to 10,000 ppm of epichlorohydrin, about 3,000 to 20,000 ppm of glycidol and about 3,000 to 10,000 ppm of hydrolyzable chlorine. The above residual glycidol and chlorine bring about the deterioration of coating material characteristics and electrical characteristics in the fields of coating materials, electronic materials and textile materials and the problem of eruption of the skin, and in recent years the residual epichlorohydrin has caused the problems of carcinogenicity and the deterioration of working environment.
It is hoped therefore, that the impurities such as glycidol and chlorine compounds including epichlorohydrin be removed as much as possible from the Glycidyl Methacrylate, etc.
As a process for producing glycidyl methacrylate capable of suppressing the content of epichlorohydrin therein to at most 100 ppm, there is disclosed a method in which water administration is carried out at the time of the reaction of an alkali metal salt of methacrylic acid with epichlorohydrin, the resultant reaction liquid is washed with diluted aqueous solution of sodium hydroxide and distillation with steam treatment is carried out (Japanese Patent Application Laid-Open No. 2818/1995). However, this method involves the problems of necessitating water regulation within a narrow range, requiring a plurality of washing steps, causing change in the properties of initial boiling components by water and thus complicating the steps. It can not be said, therefore, that this method is an industrial method excellent in economical efficiency.
There is disclosed, as a process for producing Glycidyl Methacrylate, etc. completely free from a chlorine component, a process in which an ester of Methacrylic Acid, etc. and glycidol are subjected to transesterification (Japanese Patent Application Laid-Open Nos. 18801/1972, 11542/1980, 102575/1980 and 1780/1994). This process, however, still involves the problems of poor storage stability of glycidol, liability to polymerization of the same etc.
There is also proposed a method in which allyl methacrylate or the like is epoxidized (Japanese Patent Publication No. 6289/1972 and Japanese Patent Application Laid-Open Nos. 183275/1986, 92962/1993 and 116254/1994). There still remains therein the problems of expensive starting raw materials, increasing number of steps and unfavorable economical efficiency.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide a process for producing a highly pure glycidyl ester of acrylic acid or methacrylic acid by overcoming the various shortcomings of the foregoing prior arts.
Other objects of the present invention will become obvious from the contents of this specification hereinafter disclosed.
As a result of intensive research and investigation made by the present inventors in order to achieve the aforesaid objects, it has been found that highly pure Glycidyl Methacrylate, etc. is obtained in high yield in an economically advantageous manner which contains 300 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less of harmful epichlorohydrin; 3000 ppm or less, preferably 2000 ppm or less, more preferably 1000 ppm or less of glycidol; and 3000 ppm or less, preferably 2000 ppm or less, more preferably 1000 ppm or less of hydrolyzable chlorine through a process for producing a glycidyl ester of any of acrylic acid and methacrylic acid which comprises the steps of neutralizing any of acrylic acid and methacrylic acid and at least one member selected from the group consisting of carbonates of alkali metals and bicarbonates of the same in an excess amount of epichlorohydrin while an oxygen-containing gas is blown into the liquid reaction system; subjecting water formed by the neutralization and epichlorohydrin to azeotropic distillation to discharge them outside the reaction system and to form an alkali metal salt of any of acrylic acid and methacrylic acid; subsequently adding a queternary ammonium salt as a catalyst to the reaction system to react said alkali metal salt of said acid with the epichlorohydrin and thus synthesize the glycidyl ester of said acid; then after the completion of the esterification reaction, cooling the liquid reaction product while recovering part of the excess epichlorohydrin under reduced pressure; thereafter adding aqueous solution of an alkali hydroxide to the liquid reaction product to separate the same into aqueous layer and organic layer; adding a catalyst deactivator to the resultant organic layer and subsequently distilling the organic layer to separate the glycidyl ester of said acid while blowing an oxygen-containing gas into the organic layer.
DESCRIPTION OF PREFERRED EMBODIMENTS
The epichlorohydrin, that is, excess amount of epichlorohydrin to be used in the present is preferably selected in such an amount that it is present in the reaction system at the time of neutralization reaction and at the time of esterification reaction in a molar amount of 1 to 10 times, preferably 3 to 7 times based on Methacrylic Acid, etc. An amount thereof less than the aforesaid lower limit brings about a decrease in the yield of the product due to poor agitational property of the slurry of an alkali metal salt of Methacrylic acid etc., whereas that more than the upper limit gives rise to an increase in the amount of impurities such as chlorine and lowering in economical-efficiency.
The carbonates of alkali metals and bicarbonates of the same to be used in the present are exemplified by sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate. They are used in an amount of at least one equivalent, usually preferably 1.0 to 1.7 equivalent of Methacrylic acid, etc.
Examples of the quaternary ammonium salts to be used as a reaction catalyst include tetramethylammonium chloride, trimethylethylammonium chloride, dimethyldiethylammonium chloride, methyltriethylammonium chloride, tetraethylammonium chloride, trimethylbenzylammonium chloride and triethylbenzylammonium chloride, of which are preferably usable tetramethylammonium chloride, tetraethylammonium chloride, triethylbenzylammonium chloride and trimethylbenzylammonium chloride. The quaternary ammonium salt may be used alone or in combination with at least one other optional species. The amount of the aforesaid salt to be used is usually 0.01 to 1.5 mol % based on the Methacrylic Acid, etc.
In carrying out the process according to the present invention, it is preferable that a polymerization inhibitor be present in the reaction system in any and all of the neutralization reaction, esterification reaction and distillation. Such polymerization inhibitor may be optionally selected for use from the conventional polymerization inhibitors of amine, phenols, phosphorus, sulfur or transition-metal series. The above-mentioned esterification reaction in the present invention can be put into practice under the conventional conditions.
In the process according to the present invention, part of the excess epichlorohydrin is recovered under reduced pressure after the esterification reaction. The amount of the epichlorohydrin to be recovered is 5 to 80%, preferably 10 to 60%, more preferably 20 to 40% by weight based on the excess epichlorohydrin to be used. A recovery amount thereof less than 5% by weight results in insufficient separability between the aqueous layer and organic layer, whereas that more than 80% by weight gives rise to the problem of worsenening the slurry properties of th liquid reaction product.
As the aqueous solution of an alkali hydroxide to be added to the liquid reaction product after the completion of the esterification reaction, recitation is made of the aqueous solution of at least one alkali hydroxide selected from sodium hydroxide, potassium hydroxide, calcium hydroxide and the like. The concentration of the aqueous solution is preferably 1 to 15%, more preferably 3 to 10% by weight. The amount of the aqueous solution of the alkali hydroxide to be used therein is 50 to 500 g, preferably 100 to 400 g, more preferably 150 to 300 g per one mole of the Methacrylic Acid, etc. The temperature of the crude Glycidyl Methacrylate, etc. to which the aqueous solution of the alkali hydroxide is added, is 0° to 80° C., preferably 10° to 60° C., more preferably 20° to 40° C.
In the process according to the present invention, the aqueous solution of the alkali hydroxide is added to the liquid reaction product to separate it into the aqueous layer and organic layer, and thereafter a catalyst deactivator is added to the organic layer thus obtained. There is used, as the catalyst deactivator, at least one member selected from sodium salts and calcium salts each of alkylsulfonic acid, alkylbenzenesulfonic acid, phosphotungstic acid and phosphomolybdic acid. The amount of the catalyst deactivator to be used is 1 to 70 mol %, preferably 5 to 50 mol %, more preferably 10 to 30 mol % based on the catalyst to be used.
The oxygen-containing gas to be used in the above-mentioned reaction and distillation according to the present invention is exemplified by air and a mixture of oxygen and nitrogen, and preferably has an oxygen content of 1 to 30% by volume. The amount of the oxygen-containing gas to be used is 0.1 to 500, preferably 1 to 300, more preferably 5 to 100 milliliter (mL)/min in terms of flow rate at 20° C. under atmospheric pressure per 1 kg of Glycidyl Methacrylate, etc.
The distillation procedure in the present invention can be put into practice by optionally selecting a condition.
According to the process of the present invention, it is made possible to produce in high yield, a highly pure glycidyl ester of acrylic acid or methacrylic acid which is minimized in the contents of epichlorohydrin, glycidol and hydrolyzable chlorine.
In the following the present invention will be described in more detail with reference to comparative examples and working examples, which however shall not limit the present invention thereto.
In the working examples and comparative examples, measurements were made of the purities of the starting raw materials and the objective product by GC, and of the content of hydrolyzable chlorine by the procedure described hereunder as Reference Example 1.
In the working and comparative examples, the purities (%) of the starting raw materials and the objective product, and ppm are indicated unexceptionally by purities (% by weight), and ppm on weight basis, respectively.
REFERENCE EXAMPLE 1
(Measurement Method of the Content of Hydrolyzable Chlorine)
About one mL of sample of Glycidyl Methacrylate, etc. as the product is accurately weighed in a 100 mL Erlenmeyer flask. Then 10 mL of refined methanol and 10 mL of pure water are placed in the flask to dissolve the product. Moreover, 10 mL of 5N aqueous solution of potassium hydroxide is introduced in the flask and thereafter the flask is connected to a reflux cooler and is heated in a hot water bath (90° to 100° C.) for 30 minutes to thermally decompose the product in the flask under stirring. Then the flask is taken out from the hot water bath and allowed to cool to room temperature. After the cooling the flask is disconnected from the reflux cooler, the content in the flask is neutralized with 4N nitric acid solution after adding thereto a few drops of phenolphthalein as the indicator, followed by the addition thereof in an excess amount of one mL. After the flask is mounted to an automatic titration apparatus, the content in the flask is titrated with N/1000 silver nitrate solution. A blank measurement is simultaneously made to calculate the content of hydrolyzable chlorine by the following formula.
Content of hydrolyzable chlorine (%)= (A-B)×N×f×3.546!/s
where,
A: amount of N/1000 silver nitrate solution used in titrating the sample (mL)
B: amount of N/1000 silver nitrate solution used in titrating the blank (mL)
N: normality (0.001)
f: factor of N/1000 silver nitrate solution
S: amount of weighed sample (g)
EXAMPLE 1
A 100 liter (L) stainless steel-made reaction vessel was charged with 72.0 kg of epichlorohydrin, 5.86 kg of sodium carbonate anhydride and 0.06 kg of phenothiazine to form a liquid reactant, which was raised in temperature with air blown thereinto at a rate of 1.0 L/min. When the reaction temperature reached 110° C., 8.0 kg of methacrylic acid was added to the reactant over a period of 40 minutes. Soon after the start of the addition, the epichlorohydrin and water were azeotropically distilled out and discharged-outside the reaction system. After about 30 minutes from the end of the addition, the reaction temperature was raised to 115° C. and the azeotropic distillation almost ceased, when the azeotropic distillate was obtained including 20.43 kg of epichlorohydrin layer and 1.2 kg of aqueous layer. Subsequently 0.03 kg of tetramethylammonium chloride was added to the liquid reactant to proceed with the reaction at 115° C. for one hour, while air was continuously blown thereinto at a rate of 1.0 L/min.
After the completion of the reaction, the resultant liquid reaction product was cooled to 30° C. while a part of excess epichlorohydrin (25%) was recovered under reduced pressure and subsequently incorporated with 20 kg of 3% aqueous solution of sodium hydroxide with stirring for 5 minutes. After the stoppage of air blowing, the liquid reaction product was allowed to stand to be separated into an oil layer and an aqueous layer. The oil layer was incorporated with 0.005 kg of sodium p-toluenesulfonate as a catalyst deactivator. Thereafter, epichlorohydrin was distilled away under reduced pressure and the liquid reaction product was subjected to vacuum distillation while air was blown thereinto at a rate of 0.2 L/min. As a result, there was obtained the objective glycidyl methacrylate in an amount of 12.3 kg having 98.5% purity, 76 ppm epichlorohydrin, 900 ppm glycidol and 550 ppm hydrolyzable chlorine at 93% yield.
EXAMPLE 2
The procedure in Example 1 was repeated for the synthesis of glycidyl methacrylate except that 40 g of sodium phosphotungstate was used as a catalyst deactivator in place of sodium p-toluenesulfonate, and air was blown into during the distillation at a rate of 1 L/min instead of 0.2 L/min.
As a result, there was obtained the objective glycidyl methacrylate in a yield of 90.5%, having 99.1% purity, 55 ppm epichlorohydrin, 960 ppm glycidol and 755 ppm hydrolyzable chlorine.
EXAMPLE 3
A 100 liter (L) stainless steel-made reaction vessel was charged with 72.0 kg of epichlorohydrin, 5.86 kg of sodium carbonate anhydride and 0.06 kg of phenothiazine to form liquid reactant, which was raised in temperature with air blown thereinto at a rate of 2.0 L/min. When the reaction temperature reached 110° C., 8.0 kg of methacrylic acid was added to the reactant over a period of 30 minutes. Soon after the start of the addition, the epichlorohydrin and water were azeotropically distilled out and discharged outside the reaction system. After about 30 minutes from the end of the addition, the reaction temperature was raised to 115° C. and the azeotropic distillation almost ceased, when the azeotropic distillate was obtained including 21.64 kg of epichlorohydrin layer and 1.16 kg of aqueous layer. Subsequently 0.045 kg of tetraethylammonium chloride was added to the liquid reactant to proceed with the reaction at 115° C. for one hour, while air was continuously blown thereinto at a rate of 2.0 L/min.
After the completion of the reaction, the resultant liquid reaction product was cooled to 30° C. while a part of excess epichlorohydrin (30%) was recovered under reduced pressure and subsequently incorporated with 22 kg of 5% aqueous solution of sodium hydroxide with stirring for 5 minutes. After the stoppage of air blowing, the liquid reaction product was allowed to stand to be separated into an oil layer and an aqueous layer. The oil layer was incorporated with 0.005 kg of sodium p-toluenesulfonate as a catalyst deactivator. Thereafter, epichlorohydrin was distilled away under reduced pressure and the liquid reaction product was subjected to vaccum distillation while air was blown thereinto at a rate of 0.4 L/min. As a result, there was obtained the objective glycidyl methacrylate in an amount of 12.1 kg having 98.7 purity, 68 ppm epichlorohydrin, 950 ppm glycidol and 515 ppm hydrolyzable chlorine at 91.3% yield.
COMPARATIVE EXAMPLE 1
A 100 liter (L) stainless steel-made reaction vessel was charged with 72.0 kg of epichlorohydrin, 5.86 kg of sodium carbonate anhydride and 0.06 kg of phenothiazine to form liquid reactant, which was raised in temperature with air blown thereinto at a rate of 1.0 L/min. When the reaction temperature reached 110° C., 8.0 kg of methacrylic acid was added to the reactant over a period of 30 minutes. Soon after the start of the addition, the epichlorohydrin and water were azeotropically distilled out and discharged outside the reaction system. After about 30 minutes from the end of the addition, the reaction temperature was raised to 115° C. and the azeotropic distillation almost ceased, when the azeotropic distillate was obtained including 19.32 kg of epichlorohydrin layer and 1.12 kg of aqueous layer. Subsequently 0.03 kg of tetramethylammonium chloride was added to the liquid reactant to proceed with the reaction at 115° C. for one hour, while air was continuously blown thereinto at a rate of 1.0 L/min.
After the completion of the reaction, the resultant liquid reaction product was cooled to 30° C. while a part of excess epichlorohydrin (38%) was recovered under reduced pressure and subsequently incorporated with 22 kg of water with stirring for 5 minutes. After the stoppage of air blowing, the liquid reaction product was allowed to stand to be separated into an oil layer and an aqueous layer. The oil layer was incorporated with 0.005 kg of sodium p-toluenesulfonate as a catalyst deactivator. Thereafter, epichlorohydrin was distilled away under reduced pressure and the liquid reaction product was subjected to vaccum distillation while air was blown thereinto at a rate of 0.2 L/min. As a result, there was obtained the objective glycidyl methacrylate in an amount of 12.0 kg having 98.1% purity, 592 ppm epichlorohydrin, 650 ppm glycidol and 7200 ppm hydrolyzable chlorine at 91% yield.
COMPARATIVE EXAMPLE 2
The procedure in Example 1 was repeated for the synthesis of glycidyl methacrylate except that 40 g of sodium phosphotungstate was used as a catalyst deactivator in place of sodium p-toluenesulfonate and nitrogen was blown into during the distillation at a rate of 0.2 L/min in place of air. As a result, polymerization took place during the distillation, thereby failing to produce glycidyl methacrylate.
COMPARATIVE EXAMPLE 3
The procedure in Example 1 was repeated for the synthesis of glycidyl methacrylate except that air was not blown into at the time of the reaction. As a result, polymerization took place during the reaction, thereby failing to separate the reaction product into aqueous layer and oil layer, and produce glycidyl methacrylate.
COMPARATIVE EXAMPLE 4
The procedure in Example 3 was repeated for the synthesis of glycidyl methacrylate except that any catalyst deactivator was not added prior to the distillation. As a result, residual catalyst exerted adverse influence and thus there was obtained the objective glycidyl methacrylate in a yield of only 89.3%, having 98.2% purity, 1220 ppm epichlorohydrin, 840 ppm glycidol and 420 ppm hydrolyzable chlorine.
COMPARATIVE EXAMPLE 5
The procedure in Comparative Example 1 was repeated for the synthesis of glycidyl methacrylate except that any catalyst deactivator was not added prior to the distillation. As a result, residual catalyst exerted adverse influence and thus there was obtained the objective glycidyl methacrylate in a yield of only 86.8%, having 97.3% purity, 9400 ppm epichlorohydrin, 480 ppm glycidol and 3810 ppm hydrolyzable chlorine.
COMPARATIVE EXAMPLE 6
A 100 liter (L) stainless steel-made reaction vessel was charged with 72.0 kg of epichlorohydrin, 5.86 kg of sodium carbonate anhydride and 0.06 kg of phenothiazine to form liquid reactant, which was raised in temperature with air blown thereinto at a rate of 1.0 L/min. When the reaction temperature reached 110° C., 8.0 kg of methacrylic acid was added to the reactant over a period of 30 minutes. Soon after the start of the addition, the epichlorohydrin and water were azeotropically distilled out and discharged outside the reaction system. After about 30 minutes from the end of the addition, the reaction temperature was raised to 115° C. and the azeotropic distillation almost ceased, when the azeotropic distillate was obtained including 18.82 kg of epichlorohydrin layer and 1.22 kg of aqueous layer. Subsequently 0.03 kg of tetramethylammonium chloride was added to the liquid reactant to proceed with the reaction at 115° C. for one hour, while air was continuously blown thereinto at a rate of 1.0 L/min.
After the completion of the reaction and the stoppage of air blowing, the resultant liquid reaction product was cooled to 30° C. and subsequently filtered to remove halogenated alkali. Thereafter the filtrate was returned in the reaction vessel, and epichlorohydrin was distilled away under reduced pressure and the filtered liquid reaction product was subjected to vaccum distillation while air was blown thereinto at a rate of 0.2 L/min. As a result, there was obtained the objective glycidyl methacrylate in an amount of 11.5 kg having 97.9% purity, 3940 ppm epichlorohydrin, 16520 ppm glycidol and 6800 ppm hydrolyzable chlorine at 87.2% yield.
COMPARATIVE EXAMPLE 7
The procedure in Comparative Example 6 was repeated for the synthesis of glycidyl methacrylate except that after the filtered liquid reaction product was returned in the reaction vessel, it was incorporated with 0.005 kg of sodium p-toluenesulfonate as a catalyst deactivator and subsequently, epichlorohydrin was distilled away under reduced pressure and the liquid reaction product was subjected to vaccum distillation while air was blown thereinto at a rate of 0.2 L/min. As a result, there was obtained the objective glycidyl methacrylate in a yield of only 89.6%, having 97.2% purity, 680 pm epichlorohydrin, 19970 ppm glycidol and 3300 ppm hydrolyzable chlorine.
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There is disclosed a process for producing a glycidyl ester of acrylic acid or methacrylic acid which comprises the steps of neutralizing acrylic acid or methacrylic acid with a carbonate or a bicarbonate of an alkali metal in an excess amount of epichlorohydrin while an oxygen-containing gas is blown into the liquid reaction system; subjecting water formed by the neutralization and epichlorohydrin to azeotropic distillation to discharge them outside the reaction system and to form an alkali metal salt of acrylic acid or methacrylic acid; adding a quaternary ammonium salt as a catalyst to the reaction system to react the alkali metal salt of the acid with the epichlorohydrin and thus synthesize the glycidyl ester of the acid; cooling the liquid reaction product while recovering part of the excess epichlorohydrin under reduced pressure; adding aqueous solution of an alkali hydroxide to the liquid reaction product to separate into aqueous layer and organic layer; adding a catalyst deactivator to the organic phase; and subsequently distilling the organic layer to separate the glycidyl ester of the acid while blowing an oxygen-containing gas into the organic layer. The above process makes it possible to efficiently produce a highly pure glycidyl ester of acrylic acid or methacrylic acid in high yield with minimized contents of impurities.
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TECHNICAL FIELD
The present invention relates generally to operation of nonvolatile memory arrays and specifically to operations of nonvolatile memory arrays over a wide range of operating frequencies with low power consumption below a critical frequency.
BACKGROUND ART
Non-volatile memory devices, such as electrically erasable and programmable read only memories (EEPROMs), comprise core arrays of memory cells including a variable threshold transistor. Each memory cell can include a number of transistors; at least one of which will be a variable threshold (i.e., programmable) transistor.
With reference to FIG. 1 , a portion 100 of a prior art memory array includes a plurality of memory cells 101 ; each of the plurality of memory cells 101 includes a pair of transistors, a select transistor 101 A and a variable threshold transistor (i.e., a floating gate transistor) 101 B. According to one version of the prior art, the select transistor 101 A is an n-channel enhancement transistor, and the floating gate transistor 101 B is an n-channel native transistor. Other kinds of the plurality of memory cells 101 each including a greater number of transistors are known in the prior art as well. Additionally, various arrangements of the plurality of memory cells 101 are known, such as NAND EEPROM and NOR EEPROM arrays.
The plurality of memory cells 101 is each interconnected by a plurality of wordlines lines 103 , a plurality of sense lines 105 , and a plurality of bitlines 107 . In particular, drains of the each of the select transistors 101 A are connected to one of the plurality of bitlines 107 . A gate of each of the select transistors 101 A and the floating gate transistors 101 B is each connected to one of the plurality of wordlines 103 and sense lines 107 respectively.
In FIG. 2 , a non-volatile memory arrangement 200 of the prior art includes a read select transistor 201 , a read select line 201 A, a sense amplifier 203 , a data bus 203 A, and a wordline decoder 205 . The non-volatile memory arrangement further includes one each of the select transistors 101 A and the floating gate transistors 101 B from FIG. 1 . As was the case in FIG. 1 , according to an n-channel implementation of the select 101 A and the floating gate 101 B transistors, the drain of the select transistor 101 A will be connected to one of the plurality of bitlines 107 , and respective gates of the select 101 A and the floating gate 101 B transistors are connected respectively to one of the plurality of wordlines 103 and sense lines 105 . The wordline 103 is driven by a word line decoder 205 .
The read select transistor 201 is connected to the read select line 201 A. When a read operation is active, the read select transistor 201 is turned on, thereby electrically connecting the bitline 107 to the data bus 203 A. The data bus 203 A, in turn, is connected to the sense amplifier 203 . When the non-volatile memory arrangement 200 is subject to a read operation, a conductive state of the memory cell 101 is queried by connecting the bitline 107 to the sense amplifier 203 and applying appropriate bias voltages to the selected bitline 107 , sense line 105 , and wordline 103 . If the select transistor 101 A is turned on and the bias voltage applied to the sense line 105 exceeds a threshold of the floating gate transistor 101 B, current will flow from the bitline 107 to ground through the memory cell 101 and the sense amplifier 203 will detect a “low” state. Conversely, if the bias voltage applied to the sense line 105 does not exceed the threshold of the floating gate transistor 101 B, then no current will flow through the memory cell 101 , and the sense amplifier 203 will detect a “high” state. While the sensing approach just described provides an operable memory arrangement, power consumption levels which characterize this approach are disadvantageous.
Power requirements of a contemporary memory sense amplifier are indicated in the dynamic power requirement, P dyn , as a function of operating frequency, f op , graph 300 of FIG. 3 . A constant sense amplifier consumed power trace 301 is indicative of a minimum power requirement, per wordline, any time the sense amplifier 203 ( FIG. 2 ) is in an operational mode. A minimum sense amplifier power, P min , is determined by
P min =V dd ·I SA
where V dd is the system voltage and I SA is the sense amplifier current. A linear expression of total memory array power without sense amplifiers, P array , 303 is governed by
P array =C core ·V dd 2 ·f op
where C core is determined from a total gate-source capacitance, C gs , value of each of the memory transistors within the plurality of memory cells 101 ( FIG. 1 ). A total dynamic power requirement 305 is then determined by
P dyn =( C core ·V dd 2 ·f op )+( V dd ·I SA )
which is merely a summation of the constant amplifier consumed power 301 and the linear expression of total memory array power without sense amplifiers 303 .
The dynamic power, P dyn , is a function of one variable—operating frequency, f op . Other functional dependencies, C core , V dd , and I SA , are all fixed for a given memory array configuration. Therefore, it is desirable to minimize the total dynamic power requirement, especially in situations where either the operating frequency is variable during memory array operation or a given memory array is adaptable to a range of operating frequencies within a given circuit.
SUMMARY
An automatic address transition detection (ATD) circuit and method is described herein which allows a memory device to operate over a wide range of frequencies; the circuit and method provide for operation under reduced power consumption of the device if the device is operating in accordance with a low system clock frequency (less than, for example, 1 MHz). The reduction in power consumption derives from operating sense amplifiers within the memory device with a steady-state bias current only as compared with a higher-level of current needed for reading a state of memory cells. Therefore, in a system operating at a relatively low clock frequency, the higher-level of current is supplied to the sense amplifiers only at times when they are needed for reading memory cells.
The automatic ATD circuit operates, in one embodiment, with a first delay circuit configured to accept a system clock pulse as an input and produce a delayed version of the system clock pulse as an output. The delay to the system clock is performed to allow a frequency comparison in a later part of the circuit. A rising-edge detection circuit operates when the delayed system clock is received and senses a rising-edge of the delayed system clock pulse. A pulse output from the rising-edge detection circuit feeds into a second delay circuit; the second delay circuit produces an output pulse where a period of the pulse is determined by delay characteristics of the sense amplifier and is thus independent of system clock frequency. The pulse is compared to the system clock frequency. If the system clock frequency is above a determined frequency, the automatic ATD circuit is disabled. If the clock frequency is below the determined frequency, the automatic ATD circuit is enabled and provides a sense amplifier enable signal only when a memory cell read is required.
In an exemplary embodiment of a method of operating the automatic ATD circuit, steps involve delaying an input system clock signal by a first delay period; generating a first pulse (e.g., a rising-edge pulse) based on a the delayed input system clock signal; determining a second delay period based on delay characteristics of the sense amplifier (i.e., sense amplifier characteristics of a time to turn on, a charge delay time, and a time to turn off); producing a critical signal pulse based on the generated pulse and the determined second delay period; and comparing a first period of the system clock signal to the second delay period of the critical signal pulse. If a result of the comparison determines that the first period is shorter than the second period, an address transition detection (ATD) disable pulse is produced. If a result of the comparison determines that the first period is longer than the second period, an address transition detection (ATD) enable pulse is produced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a portion of a prior art non-volatile semiconductor memory core arrangement.
FIG. 2 is a prior art non-volatile semiconductor memory arrangement, which includes a conventional sense amplifier arrangement.
FIG. 3 is a graph indicating dynamic power requirement of a prior art conventional sense amplifier arrangement as a function of operating frequency.
FIG. 4 is a graph indicating dynamic power requirements of a sense amplifier arrangement in accordance with the present invention, also indicated as a function of operating frequency.
FIG. 5A is a block diagram of an exemplary embodiment of an automatic address transition detection (ATD) circuit in accord with the present invention as used in a memory circuit.
FIG. 5B is a block diagram of an exemplary embodiment of the automatic ATD circuit of FIG. 5A .
FIG. 5C is a schematic diagram of an exemplary embodiment of a pulse-edge detector circuit as employed in the automatic ATD circuit of FIG. 5B .
FIG. 5D is a schematic diagram of an exemplary embodiment of a sense amplifier critical pulse generator circuit as employed in the automatic ATD circuit of FIG. 5B .
FIG. 5E is a schematic diagram of an exemplary embodiment of a transimpedance amplifier circuit as employed in the sense amplifier of FIG. 5A .
FIG. 6 is an exemplary timing diagram of the automatic ATD circuit of FIG. 5A .
FIG. 7 is an exemplary timing diagram of the automatic ATD circuit of FIG. 5A wherein a variable system clock frequency is employed.
DETAILED DESCRIPTION
With reference to FIG. 4 , power requirements of a memory sense amplifier in accordance with the present invention are indicated in the dynamic power requirement, P dyn , as a function of operating frequency, f op , graph 400 . A constant sense amplifier consumed power trace 401 is indicative of a minimum power requirement any time a sense amplifier is in operational mode, i.e., constantly activated. In the present invention, the sense amplifiers are frequently operating in a residual-power mode, described infra. A residual-power mode, P res , trace 403 is determined by
P res =m·V dd ·I SA,bias
where m is an integer related to a total number of bits within a wordline. Therefore, typically m is set equal to 8, 16, or 32. A linear expression of total memory array power without sense amplifiers, P array , 405 is governed by
P array =( C core ·V dd 2 ·f op )+( m·V dd ·I SA,bias )
Unlike the prior art, the dynamic power requirement here has two sets of linear traces. A first trace 405 relates to a reduced dynamic power requirement for a memory array without full sense amplifier operation and a second trace 407 relates to a reduced dynamic power requirement for a memory array with full sense amplifier operation. Both the first 405 and the second trace 407 dynamic power requirement occur prior to a critical frequency, f cr , 409 . The critical frequency relates to a “slow mode” of memory cell operation and is inversely related to a critical access period, T cr , such that
f cr =T cr −1
The critical access period term T cr will be developed shortly with reference to FIGS. 5B and 5D , infra. Dynamic power requirements are reduced at frequencies less than f cr due to a partial sense amplifier controlled power-down described in detail herein. At higher operational frequencies, that is, greater than f cr , the present invention operates with a dynamic power requirement similar to the prior art. Thus, a first high frequency operation trace 411 and a second high frequency operation trace 413 are indicative of dynamic power requirements without and with sense amplifier operation, respectively.
Automatic Address Transition Detection (ATD) Circuit
With reference to FIG. 5A , an exemplary embodiment 500 of the present invention includes an automatic ATD circuit 501 , a sense amplifier 503 , a sense amplifier bias circuit 505 , and a DQ flip-flop 507 . The embodiment is interspersed with other portions of a memory array as will be recognized by one of skill in the art. The other portions of the memory array are shown merely to provide a schematic relationship of the present invention to a typical memory array.
Below a “critical frequency,” f cr , the automatic ATD circuit 501 senses whenever an address change occurs and provides a sense amplifier enable, SA_EN, signal to activate sense amplifiers within the memory array. A user can change a system clock frequency over a large range but a system-clock-independent SA_EN signal is determined by the automatic ATD circuit 501 without operator intervention. The automatic ATD circuit 501 senses when an address (ADDR) signal transitions and sends a signal for the sense amplifier to turn on, allowing for time periods sufficient for ramp-up of current to the sense amplifier and charging of the sense amplifier lines (i.e., the sense amplifier is activated during a valid data out period. The critical frequency, f cr , is defined by particular characteristics within a given memory array circuit as explained in detail, infra. Above the critical frequency, the automatic ATD circuit 501 sends a constant SA_EN signal, allowing sense amplifiers to be constantly activated.
With reference to FIG. 5B an exemplary embodiment 501 A of the automatic ATD circuit 501 of FIG. 5A includes a delay circuit 511 , a rising-edge detection circuit 513 , a critical period delay element 515 , a first DQ flip-flop 517 , an optional DQ flip-flop 519 , and an OR gate 521 .
A skilled artisan will recognize that the delay circuit 511 may be constructed in various ways. For example, an appropriate delay may be achieved by constructing an even number of inverters is series; the higher a number of inverters placed in series, the greater the delay. The initial time delay is chosen to allow a comparison of the SYS_CLK to an output of the critical period delay element 515 , thus allowing any positive edge-triggered flip-flop to be used as a time comparator or phase detector. Therefore, if a signal input to the “D” input of the first DQ flip-flop 517 is “0” when the SYS_CLK goes high, then the system period is not short enough to disable SA_EN. Consequently, the automatic ATD detection circuit 501 remains in the “SLOW MODE” of operation ( FIG. 4 ). Details of exemplary embodiments of the rising-edge detection circuit 513 and the critical period delay element 515 are given in FIGS. 5C and 5D , respectively. Determination of whether the optional DQ flip-flop 519 is included in the automatic ATD circuit 501 A will depend upon a range of SYS_CLK frequencies to which the circuit is subjected and overall stability considerations (e.g., when a period of the SYS_CLK is close to the critical period, T cr ). Such stability considerations are determinable by a skilled artisan (e.g., by circuit simulation).
Operation of the exemplary automatic ATD circuit 501 A is independent of a frequency of the system clock, SYS_CLK input. Instead, the exemplary automatic ATD circuit 501 A simply relies on the frequency of the SYS_CLK signal to determine when to produce a sense amplifier enable, SA_EN, signal and a duration of the signal.
Timing diagrams of FIG. 5B indicate a SA_EN signal for two different SYS_CLK frequencies, f 1 and f 2 . Recall that a period is simply an inverse of a clock frequency; thus
f 1 = 1 T 1
The automatic address transition detection circuit 501 A compares frequencies of the SYS_CLK and an output of the critical period delay element 515 . An SA_EN signal is therefore produced only if a negative edge of the SAE_CR pulse (i.e., an output of the critical period delay element 515 ) occurs before a subsequent rising-edge of the SYS_CLK. T cr is thus chosen to be longest period that will, overall, allow the sense amplifier 503 ( FIG. 5A ) to be on for the least amount of time possible, thereby saving power, but long enough in time to determine a memory cell state after an ATD signal occurs. Details of determination of the critical period, T cr , and relationships between the ADDR and SA_EN are developed with reference to FIGS. 5D and 6 , infra.
Operation of the Automatic ATD Circuit (f 1 <f cr )
For a SYS_CLK frequency f 1 , a value of f 1 is such that T 1 >T cr . In this case, a SYS_CLK signal, shown at “A,” is delayed, “B,” by the delay circuit 511 . A single pulse, at “C,” is produced as an output of the rising-edge detection circuit 513 . The single pulse at “C” is input to the critical period delay element 515 . A resultant pulse from the critical period delay element, at “D,” having a period T cr , produces a SAE_CR pulse which is one of at least two signal inputs to the OR gate 521 . (Details of the critical period delay element 515 are provided with reference to FIG. 5D , infra.) The SYS_CLK initiates the pulse train at “D” and also provides an enable signal to the first DQ flip-flop 517 (as well as the optional DQ flip-flop 519 if present) on a rising-edge 523 of the f 1 SYS_CLK signal. Since the resultant pulse from the critical period delay element, at “D,” is low, a “0” is latched into the first DQ flip-flop 517 . As long as a period of the SYS_CLK is greater than T cr , (i.e., a frequency of the SYS_CLK is less than the critical frequency, f cr (FIG. 4 )), then an SA_EN signal will only be produced when an address transition detection (ATD) occurs.
Operation of the Automatic ATD Circuit (f 2 >f cr )
For a SYS_CLK frequency f 2 , a value of f 2 is such that its related period T 2 <T cr . In this case, a high frequency SYS_CLK signal, at “A,” is again delayed, shown at “B,” by the delay circuit 511 . As shown at “C,” a single pulse is produced as an output of the rising-edge detection circuit 513 . The single pulse at “C” is input to the critical period delay element 515 . The resultant pulse (i.e., the same pulse as describe supra with respect to the SYS_CLK frequency at f 1 ) from the critical period delay element, at “D,” having period T cr , produces a SAE_CR pulse which is input to the OR gate 521 . The SYS_CLK still initiates the pulse train at “D” and also provides an enable signal to the first DQ flip-flop 517 (and the optional DQ flip-flop 519 ) on a rising-edge 525 of the f 2 SYS_CLK signal. Here however, since the resultant pulse from the critical period delay element, at “D,” is high, a “1” is latched into the first DQ flip-flop 517 . Consequently an SA_EN signal appears high at an output of the OR gate 521 .
Operation of the Rising-Edge Detection Circuit
With reference to FIG. 5C , an exemplary embodiment of a rising-edge detection circuit 513 A includes a first inverter 531 , a second inverter 533 , a PMOS transistor 535 , an NMOS transistor 537 , a third inverter 539 , and a AND gate 541 . Additionally included are analog components; a resistor having a value “r” and a capacitor having a value “c.” The rising-edge detection circuit 513 A is thus a hybrid analog-digital circuit. A combination of the PMOS transistor 535 and the NMOS transistor 537 essentially act as an inverter element. However, a combined effect of the resistor and capacitor produce a time constant, τ, such that a minimum time delay value, ∂ min , is the product of the resistive and capacitive values multiplied by the natural log value of “2.” Thus
∂ min =rc ·[ln(2)]
where ∂ min neglects minimal effects of digital component propagation delays. Consequently, any signal through the lower inverter leg portion of the rising-edge detection circuit 513 A will be further delayed in comparison to the signal traveling through the upper leg due to the lower leg analog components. For example, assuming a rising-edge appears at an input to the rising-edge detection circuit 513 A, a “fast 1” is produced at point “A.” After the first inverter 531 , a resulting “0” makes its way to the bottom leg, causing the PMOS transistor 535 to act as a pull-up device, creating a “1” as an input to the third inverter 539 . However, due to the delay going through the resistive and capacitive analog components, the signal is delayed by ∂ min prior to passing through the third inverter 539 . At point “B,” a “slow 0” (or, otherwise put, a lingering “one”) is present due to the analog delay. Thus, a signal output from the AND gate 541 produces a narrow pulse only at times when both the top leg and bottom leg each are producing a high signal. A width, w, appropriate as an input to the critical period delay element 515 ( FIG. 5B ), may thus be chosen through proper selection of the resistive and capacitive elements.
Operation of the Critical Period Delay Element
With reference to FIG. 5D , an exemplary embodiment of a critical period delay element 515 A produces an output pulse having a width Δt based on the input pulse trigger from the rising-edge detection circuit 513 . A critical period, T c , is determined (for example, by circuit simulation) such that
T C =t on +t SA — delay +t off
where t on , t SA — delay , and t off will be defined with reference to FIG. 6 , infra. The critical period delay element 515 A includes a PMOS transistor 551 , an NMOS transistor 553 , a resistor, a capacitor, and an inverter 555 . The critical period delay element 515 A functions similarly to the lower leg of the rising-edge detection circuit 513 A. Here, Δt=RC·[ln(2)], where “R” and “C” are resistive and capacitive values respectively that are chosen to give a pulse width Δt equal to the critical period, T C . The minimum width, w, of the input pulse output from the rising-edge detection circuit 513 A ( FIG. 5C ) is chosen to be long enough to fully discharge the capacitor. For this application, a value of the input pulse width, w, is typically less than 5 nanoseconds with an exemplary value of 3 nanoseconds minimizing total circuit delays. A trip point voltage, V tp , at point “A” sufficient to cause the inverter 555 to change states is simply
V tp = V dd 2
where V dd is the system supply voltage.
Sense Amplifier Design
With reference to FIG. 5E , an exemplary sense amplifier 503 A is based on a transimpedance amplifier design, described in detail in U.S. Pat. No. 5,493,533, to Emil Lambrache (the inventor of the present invention described herein). U.S. Pat. No. 5,493,533 is hereby incorporated by reference in its entirety.
In brief, the sense amplifier 503 A is designed such that an output voltage, V out , is a function of a transimpedance transfer function, Z f , input current, I in , a reference current, I ref , and the supply voltage, V dd , according to the formula
V out = Z f ( - I in + I ref ) + V dd 2
and V out is a digital output voltage based on analog current inputs where I in =I cell when reading a programmed memory cell such that
V out = { 0 ; for I in ≥ I ref when I in = I cell V dd ; for I in ≥ I ref when I in = 0 ( erased cell )
Further design considerations include determining a transimpedance transfer function, Z f , such that
Z ref · I ref = V dd 2
and determining a reference current I ref such that
I ref = I cell 2 ,
where I cell ≅10 μA for a typical programmed memory cell.
Representative Timing Diagrams
With reference to FIG. 6 , an exemplary timing diagram of the automatic ATD circuit of FIG. 5A has a sense amplifier current graph, I SA that begins to ramp up to a steady sense amplifier bias current, I SA — bias , as soon as a read enable, READ_EN, signal is asserted. Depending upon characteristics of the sense amplifier circuit, the sense amplifier bias current achieves a steady-state condition typically within 1 μs–10 μs. An address transition signal, ADDR[n:1], may be asserted after the SYS_CLK goes high. Upon detection of an ADDR[n:1] signal, the automatic ATD control circuit 501 ( FIG. 5A ) sends an SA_EN signal to the sense amplifier 503 , causing charge to be pumped into the sense amplifier (i.e., charge capacitor gate-to-source, C g-s to pump an electron charge into a channel of the transistor). A time delay, t on , occurs while the sense amplifier is being charged. There is an additional delay, t SA — delay , that occurs while sense amplifier lines to the memory cell are charging. After the lines are fully charged, an SA_CLK signal is asserted, allowing a data output, D out , to be latched into the DQ flip-flop 507 ( FIG. 5A ). D out will be valid until the SA_EN signal goes low, forcing the sense amplifier current to return to an I SA — bias condition after a slight delay period, t off , where charge is bled off. Thus, a significant power savings may be realized by employing the automatic ATD control circuit. For example, if a low speed SYS_CLK operation has a frequency of 1 MHz and an SA_EN signal of 100 nsec is sufficient to enable data from a memory cell, then only
100 n sec 1 μsec = 10 %
of the power required to keep a sense amplifier at full power constantly is utilized by adoption of the present invention. Therefore, the critical time period, T c , noted above with regard to FIG. 5D (recall that T c =t on +t SA — delay +t off ) is calculated based on the delay times referenced in the I SA graph.
Note further that as the SYS_CLK frequency increases to a frequency slightly greater than t SA — delay , there is no advantage in turning the sense amplifier off as an inherent charge wasted (indicated by an integration of the hatched areas “A” representing charge pumped in during t on and charge bled off during t off ) is greater than any possible energy savings. However, the SYS_CLK frequency may be constantly changed and the automatic ATD control circuit 501 will determine an optimal timing determination for turning the sense amplifier on or off or leaving the sense amplifier on constantly. This automatic determination feature is exemplified with reference to FIGS. 5B and 7 .
FIG. 7 indicates a SYS_CLK at a first frequency until point “A” whereupon the SYS_CLK switches to a second frequency. At point “B” the SYS_CLK changes to a third frequency (or back to the first frequency). An EDGE DETECT graph indicates an output from the rising-edge detection circuit 513 (point “C” in FIG. 5B ). Note that both a width of the edge detect pulse and an SAE_CR signal are constant despite a change in the SYS_CLK frequency. For example, note that at a rising-edge of the SYS_CLK at a first rising-edge time 703 1 , an output of the critical period delay element 515 (point “D” in FIG. 5B ) goes high and returns to “0” prior to the next rising-edge of the SYS_CLK pulse at a second rising-edge time 703 2 . Thus the circuit is operating in a low power operation mode, keeping the sense amplifier in a low power mode (i.e., “SLOW MODE,” FIG. 4 ) by supplying operational current to the sense amplifier only as long as needed. However, at point “B” where the SYS_CLK frequency changes to a frequency greater than the critical frequency, f cr , ( FIG. 4 ) such that the SAE_CR pulse is unable to return to “0” prior to a subsequent rising clock edge of the SYS_CLK at a third rising-edge time 7033 . Thus, the output of the first flip-flop 517 which is an ATD_DISABLE signal is asserted at the third rising-edge time 703 3 and remains high during a period of high frequency operation 705 continuing through subsequent rising-edge times 703 4 , 703 5 . The optional DQ flip-flop 519 creates a second ATD_DISABLE signal in case the first one has a glitch when f is approximately equal to f cr and the first DQ flip-flop 517 is left in a metastable state. During the second low frequency operation period 707 , the automatic ATD control circuit 501 restarts the low power operation mode beginning at a fourth rising-edge time 703 6 .
In the foregoing specification, the present invention has been described with reference to specific embodiments thereof. It will, however, be evident to a skilled artisan that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. For example, skilled artisans will appreciate that the DQ flip-flops of FIG. 5B may be substituted with other components to achieve a similar time comparison function. For example, a Schmitt trigger could be used in place of the optional DQ flip-flop 519 of FIG. 5B . Further, other circuits may be substituted for the rising-edge detection circuit 513 A and the critical period delay element 515 A of FIGS. 5C and 5D respectively. Further, the rising-edge detection circuit may be reconfigured, with appropriate timing considerations, to operate on a falling-edge of the clock. The resistors and capacitors described herein may similarly be substituted by appropriate resistive and capacitive elements as known in the art. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
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An automatic ATD control circuit operates with a first delay circuit accepting a system clock pulse as an input and producing a delayed version of the system clock pulse as an output. The delay to the system clock is performed to allow a frequency comparison in a later part of the circuit. An edge detection circuit operates when the delayed system clock is received and senses an edge of the delayed system clock pulse. A pulse output from the edge detection circuit feeds into a second delay circuit; the second delay circuit produces an output pulse where a period of the pulse is determined by delay characteristics of the sense amplifier and is thus independent of system clock frequency. The pulse is compared to the system clock frequency. If the system clock frequency is above a determined frequency, the automatic ATD control circuit is disabled.
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TECHNICAL FIELD
The present invention relates to a suspension mechanism in automatic washing machines with horizontal axis, loaded from the front or from the top, providing the positioning of the tub ( 2 ) and its vibratory movement in the cabinet ( 1 ).
Automatic washing machines are electrical appliances wherein the clothes loaded into a cylindirical drum ( 3 ) are washed by the agitation/fluctuations created by the rotation of the drum ( 3 ). The basic functions of the machine such as water and detergent intake, washing, rinsing, spindrying and water discharge are performed automatically and according to a predetermined program. Washing machines with horizontal axis are characterized in that the rotational axis of the drum ( 3 ) wherein the laundry is loaded, is parallel or inclined at an angle smaller than 45° to the ground. There are two major types of automatic washing machines with horizontal axis, with regard to the location of the loading door, namely front-loading and top-loading machines. In the front-loading machines with horizontal axis, the opening axis of the loading door is perpendicular to the axis of the drum ( 3 ) rotary axis and it is perpendicular or at some angle to the floor in front of the cabinet ( 1 ), depending on whether the drum ( 3 ) rotary axis is parallel or at a certain angle to the floor. Whereas in the top-loading horizontal axis machines, the door is on top of the cabinet ( 1 ) and its opening axis is parallel to and above the drum ( 3 ) rotary axis.
The tub assembly comprising the drum ( 3 ) vibrates due to the non-uniform and unbalanced distribution of the laundry in the drum ( 3 ) because of such processes as inserting the clothes in the water and taking them out, and dropping them down from certain heights with the rotary motion of the drum ( 3 ) during the washing cycle and the laundry taking a lumpy form during rinsing and spinning operations. The suspension mechanism is an arrangement consisting of such components as springs ( 4 ), dampers ( 5 ) and the like, to be used for the purpose of damping (suppressing) these vibrations and transferring them to the cabinet ( 1 ) of the machine so that the user will not be disturbed.
STATE OF ART RELATED TO THE INVENTION
The components making up the automatic washing machines with horizontal axis can be classified in general terms as: a cabinet ( 1 ), moving tub ( 2 ) assembly, suspension mechanism and water connection parts.
The cabinet ( 1 ) is provided with the detergent dispenser, control panel, laundry loading door, pump, water inlet and outlet hoses. As mentioned above, the laundry loading door is in front of the cabinet ( 1 ) in front-loading machines and is on top of the cabinet ( 1 ) in top-loading machines.
The moving tub assembly consists of; a drum ( 2 ), counter weights fixed on the drum ( 2 ), a roller bearing at the rear surface of the tub ( 2 ), a cylindrical shaft passing through the said roller bearing and making rotating movement, a flange fixed to this shaft, a geometrically symmetric drum ( 3 ) connected to the shaft by means of the said flange, a heater placed between the outer surface of the drum ( 3 ) and the inner surface of the tub ( 2 ), an electrical motor mounted below or behind the tub ( 2 ) or in the roller bearing, moment transmission components such as belt, pulley, gear assembly, etc., providing the transmission of the motor movement to the shaft-flange-drum group. The drum ( 3 ) rotates around its axis of symmetry, by means of these moment transmission components in case the motor is below the tub ( 2 ), and by means of the rotative movement transmitted directly to the shaft, in case it is above the roller bearing. On the inner surface of the drum ( 3 ) wherein the laundry is loaded, are a plurality of baffles and on its outer surface are a plurality of small holes/piercings. In some machines, on the front and/or rear surfaces there are balancing components with moving small masses therein.
The moving tub assembly making vibratory movements in the machine, is connected to the cabinet ( 1 ) by means of a suspension mechanism consisting of such components as spring ( 4 ) and damper ( 5 ). In the suspension mechanisms formed by the conventional technique, one or more spring (s) [ 4 ] and/or damper (s) [ 5 ]; and/or spring-damper which functions as spring and damper, are used. By means of elastic bellow, placed on the body ( 1 ) between the loading door and the front surface of the tub, water is retained in the tub ( 2 ), prevented to leak out of the tub ( 2 ) during the operation of the machine.
Washing is a process provided by the rotational movements of the drum ( 3 ) to left or to right, and by its stopping and waiting for a certain period without rotating, after controlling such parameters as direction, speed, time period, angle of rotation; amount, type, temperature of the washing water; type, amount of chemical cleaning agents are controlled. During this process, the rotative speed of the drum ( 3 ) is such that it will not allow the laundry within the drum are spinned on the wall of the drum due to the centrifugal force and rotate together with the drum. The baffles on the inner surfaces of the drum ( 3 ) provide the movement, raising and dropping and tumbling of the laundry inside the drum during washing and can also serve to circulate the water within the drum.
During the rinsing cycle, following the washing cycle, generally the drum ( 3 ) will rotate together with the laundry it contains, under the effect of centrifugal force: however it is rotated at low speeds so that an excessive imbalance will not be created because of the high amount of water. During this process an important portion of water remained in the laundry is discharged into the tub ( 2 ) under the effect of the centrifugal forces created by the rotation of the drum ( 3 ), out of the drum holes. Controls are made in order to determine the rotational speed of the drum ( 3 ) wherein a high speed spinning will be realized.
After the completion of washing and rinsing phases, during the spinning cycle some more of the remaining water in the drum is discharged into the tub ( 2 ) through the drum ( 3 ) holes, due to the high centrifugal forces created by the high speed rotation of the drum. Then water accumulated in the tub ( 2 ) is evacuated from the machine by means of a pump and the water discharge hose.
In the patent application No. EP 0 655 111 system consisting of metal cables with elastic, anti-impact and anti-vibration properties developed for supporting a rotary unit within a fixed frame, is explained. However, this system is completely different from the invention disclosed in this application in such points as its being metallic, its being connected to the tub and body at a single point and its basically functioning as a spring.
TECHNICAL PROBLEMS AIMED TO BE SOLVED BY THE INVENTION
The tub assembly including the drum ( 3 ) makes vibratory movements in the cabinet ( 1 ) in the washing cycle during the rotation of the drum, due to the immersion of the laundry into the washing water and taking it out and to the dropping of the laundry from certain heights within the drum i.e tumbling of the laundry: and in rinsing and spinning cycles, the non-uniform distribution of the laundry taking lumpy forms within the drum ( 3 ).
In the known suspension mechanisms; the resistance parameters of the springs ( 4 ) and damping parameters of the dampers ( 5 ), taken into consideration together with weight of the moving tub assembly and the resistance and/or damping parameters of such components as the bellows placed between the tub assembly ( 2 ) and the cabinet ( 1 ), or water hoses etc., should be “rigid” enough so that the tub assembly can easily make vibratory movements without hitting the fixed components, but it should also be ‘soft’ enough to transmit the forces created due to vibration without causing the cabinet ( 1 ) to move on the floor. In other words, a “too rigid” suspension mechanism decreases the vibration of the tub assembly but increases the possibility of the cabinet ( 1 ) moving on the floor whereas a too ‘soft’ suspension mechanism reduces the possibility of its moving oil the floor but causes an increase in the vibratory movements of the tub assembly and subsequently the possibility of hitting the fixed components.
Another parameter defining the resistance/damping properties of the suspension mechanism and preventing it from being “too soft” is the necessity of preventing the tub assembly from sinking too much into the cabinet ( 1 ) and consequently preventing the centers of the drum ( 3 ) rotational axis and the laundry loading gate on top of the cabinet ( 1 ) from being differentiated. In such a case, the rubber bellow-like gasket placed between the laundry loading gate and the drum ( 3 ) will be worn out and/or will draw the resistance/damping parameters of the suspension mechanism to unwanted levels due to its excessive deformation.
The objective of the present invention is to provide the suspension of the tub assembly in such a manner that it can vibrate freely in the body, by using the elastic bands ( 6 ) instead of the suspension mechanism components such as spring ( 4 ), damper ( 5 ) etc. that arc used in the conventional systems or together with them. The required resistance and damping parameters are obtained by sizing the bands ( 6 ) appropriately, by the elasticity of the bands and (or by their reciprocal movements with friction on the tub ( 2 ) as shown in FIG. 6, consequently the vibrations of the tub assembly are suppressed and transmitted to the fixed exterior cabinet ( 1 ) of the machine so that they would not disturb the user.
Another objective of the present invention is to make the suspension mechanism “softer” than the stiffness degree implemented by the existing technique, in other words, to reduce the resistance/damping parameters of the suspension mechanism, with or without the suspension mechanism components such as spring ( 4 ), damper ( 5 ) etc. that are used in the conventional systems, so that the bellow component located between the loading door and the drum ( 3 ) will not be worn off and it will not draw the resistance/damping parameters of the suspension mechanism to unwanted levels due to its excessive deformation. In this way the impact of the tub assembly to the fixed components will be prevented and it will be possible to reduce the movement of the cabinet ( 1 ) on the floor so that the sinking of the tub assembly into the cabinet ( 1 ) due to the weight of the washing water taken into the tub ( 2 ) during the operation of the washing machine and consequently the differentiation between the centers of the drum ( 3 ) rotational axis and the loading door will the prevented.
Yet another objective of the present invention is the use of elastic bands ( 6 ) being the subject matter of the invention, in the place of such suspension mechanism components as spring ( 4 ), damper ( 5 ) etc. without using them. In this way, it will be possible to reduce the size of the space required between the structure body ( 1 ) and the tub assembly due to the geometrical structures of the known suspension mechanism components; consequently, to reduce the total volume and weight of the machine; or with the same body ( 1 ) dimensions, to provide the utilisation of the gained extra volume for other purposes; to carry the production and installation procedures of the suspension mechanism in a more economical way than the conventional technique from the standpoint of cost and time.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 a , is the perspective view showing the use of one band ( 6 ) lying on a plane to traverse the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 1 b , is the perspective view showing the use of two bands ( 6 ) each one lying on two separate planes traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )).
FIG. 1 c , is the perspective view showing the use of one band ( 6 ) lying on a plane crossing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )) longitudinally,
FIG. 1 d , is the perspective view showing the use of two bands ( 6 ) each lying on two separate planes crossing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )) longitudinally,
FIG. 2 a , is the perspective view showing the use of two bands ( 6 ) lying on a plane traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 2 b , is the perspective view showing the use of four bands ( 6 ) each pair lying on two separate planes traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 2 c , is the perspective view showing the use of two bands ( 6 ) lying on one plane crossing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )) longitudinally;
FIG. 2 d , is the perspective view showing the use of four bands ( 6 ) each pair lying on two separate planes crossing the geomiietrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )) longitudinally;
FIG. 3 a , is the perspective view showing the use of three bands ( 6 ) lying on a plane traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 3 b , is the perspective view showing the use of six bands ( 6 ) three each lying on two separate planes traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 4 a , is the perspective view showing the use of four bands ( 6 ) lying on a plane traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 4 b , is the perspective view showing the use of eight bands ( 6 ) four each lying on two separate planes traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ));
FIG. 5 a , is the perspective view showing the use of two bands ( 6 ) lying on a plane traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ) and two bands ( 6 ) lying on a plane crossing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )) longitudinally;
FIG. 5 b , is the perspective view showing the use of four bands ( 6 ) two each lying on two separate planes traversing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ) and four bands ( 6 ) two each lying on two separate planes crossing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 )) longitudinally;
FIG. 6 a , shows the connection of the bands ( 6 ) to the tub ( 2 ) in a rigid way, in a perspective view;
FIG. 6 b , shows the connection of the bands ( 6 ) to the tub ( 2 ) in a rigid way, movably on the tub, in a perspective view;
FIG. 6 c , show the connection of a separate part incorporated to the center of the bands ( 6 ) so that it can move over the tub ( 2 ), in a perspective view;
FIG. 6 d , show the connection of a separate part incorporated to the center of the bands ( 6 ), on their upper and lower surfaces so that it can move over the tub ( 2 ), in a perspective view;
FIG. 7 a , shows schematically the connection of the fastening parts ( 8 a , 8 b ) joined to the ends of the bands ( 6 ) by attaching them to a long pin ( 9 b ) to which other bands can also be fastened in such a manner that they are mutually opposed and side by side, to the cabinet ( 1 ).
FIG. 7 b , shows schematically the connection of the fastening parts ( 8 a , 8 b ) joined to the ends of the bands ( 6 ) by attaching them to a pin ( 9 a ) slightly longer than the width of the bands on which only two bands are attached; in such a manner that they are mutually opposed and side to side to the cabinet ( 1 );
FIGS. 7 c and 7 e , shows schematically the connection of the fastening parts ( 8 c , 8 d and 8 e , 8 f ) joined to the ends of the bands ( 6 ) so that they mutually interlock with each other, to the cabinet ( 1 ), by attaching them to a long pin ( 9 b ) to which other bands can also be fastened, in two embodiments of the invention;
FIGS. 7 d and 7 f , shows schematically the connection of the fastening parts ( 8 c , 8 d and 8 e , 8 f ) joined to the ends of the bands ( 6 ) so that they mutually interlock with each other, to the cabinet ( 1 ), by attaching them to a pin ( 9 a ) that is slightly longer than the width of the bands on which only two bands are attached, in two embodiments of invention;
FIGS. 8 a - 8 d show bands formed of cables, thin wires, in cylindrical form, and in braided form, respectively.
DESCRIPTION OF THE INVENTION
The suspension mechanism according to the invention, consists of the connection of the moving tub assembly within the machine to the cabinet ( 1 ) by using one or more elastic bands (s) ( 6 ) made of preferably but not limited to, elastomer based elastic material, lying on one or more plane (s) traversing and/or crossing longitudinally the geometrical axis of the tub ( 2 ) (and the rotational axis of tile drum ( 3 )) or, are perpendicular and/or parallel with regard to the floor.
In the suspension mechanism of the invention;
The bands ( 6 ) may be used in the place of the suspension mechanism components of the conventional technique, such as spring ( 4 ), damper ( 5 ), etc. or together with them;
Some or all of the bands can be connected rigidly so that they support the weight of the tub assembly or they can be connected loosely so that some or all of them will start functioning only after some movement of the tub assembly;
Bands can be of any cross section, preferably with a rectangular cross section and are dimensioned to provide the required resistance and damping properties;
The bands can have a continuous cross section or have discontinuities with holes of various sizes;
Two or more of the bands ( 6 ) on the same plane are connected in parallel and/or at a small angle with regard to each other.
The connections ( 7 ) of the bands ( 6 ) to the tub ( 2 ) can be realised on the tub ( 2 ) peripheral iron sheet and/or front and rear iron sheets, at one or more points; in such a manner that:
one or more bands (s) are connected to the tub ( 2 ) rigidly by using a complementary piece ( 7 a ) (FIG. 6 a ), and/or
by using a complementary piece ( 7 b ) to allow one or more bands (s) to make reciprocal movements on the tub (FIG. 6 b ) and/or
by using a complementary piece ( 7 c ) to allow one or more band (s) joined by a different piece ( 7 e ), to make reciprocal movements on the tub ( 2 ) (FIG. 6 c ), and/or
by using a complementary piece ( 7 d ) to allow one or more pieces (s) ( 7 f ) fastened to the lower and/or upper surfaces of one or more bands (FIG. 6 d ).
Both ends ( 8 ) of the bands ( 6 ) are formed by various production techniques to make their connection to the cabinet ( 1 ) possible or are fixed to the intermediary pieces ( 8 a , 8 b , 8 c , 8 d , 8 e , 8 f ) which are formed for this purpose.
These intermediary pieces, as shown in FIG. 7, form a set when they are attached on a pin ( 9 ) in an opposing position, in such a manner that they are side by side ( 8 a , 8 b ) or that they interlock with each other ( 8 c , 8 d , or 8 e , 8 f ). For the fixation of these bands ( 6 ) onto the cabinet ( 1 ), the cabinet is provided with some components with which one or more band end (s) will be engaged. These components ( 9 ) shown in FIG. 7 can be in the form of:
pin-like components slightly wider than the width of the bands ( 6 ), on which each band end ( 6 ), is attached separately; or
pin-like components ( 9 a ) slightly wider than the width of the bands ( 6 ), on which mutually opposed two band ( 6 ) ends are attached side-by-side or interlocking with each other; or
pins ( 9 b ) extending from the front to the rear side on which one or mutually opposed two band ( 6 ) ends at different planes (e.g. at two different planes in the front and at the back of the tub ( 2 )) are attached side-by-side or interlocking with each other.
For illustrative purposes:
FIGS. 1 a and 1 b show respectively the use of one band ( 6 ) each at one and two planes perspectively;
FIGS. 2 a and 2 b show respectively the use of two bands ( 6 ) each pair at one and two planes perspectively;
FIGS. 3 a and 3 b show respectively the use of three bands ( 6 ) each three at one and two planes perspectively;
FIGS. 4 a and 4 b show respectively the use of four bands ( 6 ) each four at one and two planes perspectively;
In these examples, the tub assembly has a cylindrical structure that is parallel to the ground and the connection plane of the bands ( 6 ) traverses the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis). In case the tub assembly is positioned as inclined at an angle smaller than 45° to the ground, the connection planes of the bands may also be inclined at a certain angle towards the ground, traversing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) the same way, or can be perpendicular to the ground and consequently traversing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) at a certain angle.
FIGS. 1 c and 1 d show respectively the use of one band ( 10 ) each, crossing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) longitudinally at one and two planes. whereas FIGS. 2 c and 2 d show respectively the use of two bands ( 6 ) each, crossing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) at one and two planes.
Each connection detail shown as examples in FIGS. 1 , 2 , 3 and 4 , can be used separately or in combination with each other. FIG. 5 a , presented as an example of referred combination forms, is the perspective view showing the use of two bands ( 6 ) on a plane traversing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) and the use of two bands ( 6 ) on a plane crossing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) longitudinally; whereas FIG. 5 b is the perspective view of the use of two bands each ( 6 ) on two separate planes traversing the tub ( 2 ) geometrical axis (and drum ( 3 ) rotational axis) and the use of two bands ( 6 ) each lying on two separate planes crossing the geometrical axis of the tub ( 2 ) (and the rotational axis of the drum ( 3 ) longitudinally.
In a specific embodiment shown in FIGS. 1 a and 1 b , wherein the bands ( 6 ) of the invention are used in addition to (as supplementary) such components as spring ( 4 ), damper ( 5 ), etc., one or more elastic bands ( 6 ) with following properties are used:
Connected to the cabinet ( 1 ) from bath ends and to the tub ( 2 ) from at least one point at the intermediary region, so that they extend below the tub ( 2 ) inside the cabinet ( 1 )
When there is no water in the tub ( 2 ), loose enough not to have any resistance/damping effect on the tub in the position where the drum ( 3 ) axis and the front door axis coincide with each other;
When the tub ( 2 ) is filled with water, the tub assembly sinks down and is supported by these bands which apply a certain force to avoid the tub assembly from further sinking down,
These bands loosen again after the water in the tub ( 2 ) is discharged and the tub assembly rises up again and thereafter the bands do not apply any force on the tub assembly during rinsing and spinning phases.
It will be appreciated that the bands may also be formed of cables 10 or thin wires 11 . Additionally, the bands may be in cylindrical form as illustrated in FIG. 8 c at 12 or it may be in braided form as illustrated at 13 in FIG. 8 d .
MODE OF APPLYING THE INVENTION TO INDUSTRY
Due to the present invention, it has been possible to reduce the total volume occupied by the washing machine and therefore to reduce its weight without changing the capacity of washing. Thus;
transportation of the machine from the production plant to the sales point and from the sales point to the user s property becomes more economical and easier;
accomodation and/or displacing of the machine in such volumes as kitchen, bathroom etc. of the user is easier.
In case the machine cabinet ( 1 ) according to the invention is manufactured with the same dimensions as the conventional machines, it is also possible to place the laundry loading door higher and consequently in a more ergonomical way than those in the conventional machines and to use the additional volume provided by this way for other purposes.
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The present invention relates to a suspension mechanism in automatic washing machines with horizontal axis, consisting of connecting the moving tub assembly ( 2 ) with cabinet ( 1 ), using one or more elastic band(s) ( 6 ) on one or more plane(s) crossing the tub ( 2 ) geometrical axis, (and drum ( 3 ) rotary axis) laterally or longitudinally. Some or all of the bands may be connected in a stretched manner so that they could support the weight of the tub assembly or they may be connected loosely so that they will start to operate after some movement of the tub assembly. The resistance and damping parameters for the suspension mechanism are provided by properly dimensioning the bands, and by their reciprocal movements with friction on the tub and/or by their own elasticity.
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BACKGROUND OF THE INVENTION
This application is a continuation-in-part of prior U.S. application Ser. No. 434,182, filed Oct. 14, 1982, now U.S. Pat. No. 4,486,539.
The present invention relates to a kit for the detection of microbial nucleic acids and a method for identifying said nucleic acids using a one-step sandwich hybridization technique.
In traditional microbial diagnostics the presence of a microbe in a given sample is demonstrated by isolating the microbe in question. After enrichment cultivations, the microbe is identified either on the basis of its biochemical properties or its immunological properties. Both methods of identification require that the microbe in the sample be viable. Such identification can be laborious and time-consuming. Indeed, the detection of certain viruses, requiring sophisticated biochemical purification or tissue culture techniques, can take as long as 4 to 6 weeks.
The purpose of this invention is to provide a diagnostic kit for detecting the nucleic acid of a microbe in a sample with the aid of a sensitive and specific nucleic acid hybridization technique. The nucleic acid may be of two types, deoxyribonucleic acid (DNA) or ribonucleic acid (RNA).
Nucleic acid hybridization is an old and well known method for investigating the identity of nucleic acids. Hybridization is based on complementary base pairing. When single-stranded nucleic acids are incubated in solution, complementary base sequences pair to form double-stranded stable hydrid molecules. The double-stranded hybrid molecules can be separated from the single-stranded molecules by chemical means.
Some methods based on the identification of nucleic acid(s) have already been applied to microbial diagnostics. Enterotoxigenic Escherichia coli has been identified from fecal samples by colony hybridization using the gene for toxin production as a probe. Positive hybridization has been demonstrated by autoradiography (see Moseley et al., Journal of Infectious Diseases, Vol. 142, pp. 892-898 (1980). Grunstein and Hogness have reported a method for detecting nucleic acids by colony hybridization in Proc. Natl. Acad. Sci. USA, Vol. 72, pp. 3961-3965 (1975). Hybridization has also been used as a method to distinguish between Herpes simplex virus type 1 and type 2 after enrichment cultivation (see Brautigam et al., Journal of Clinical Microbiology, Vol. 12, pp. 226-234 (1980). In the latter method, the double-stranded hybrid was separated from the single-stranded nucleic acid by affinity chromatography.
Brandsma and Miller have identified DNA from cells infected with Epstein-Barr virus by hybridizing filters containing immobilized Epstein-Barr virus DNA with a radioactive probe, positive hybridation being detected by autoradiography as described in Proc. Natl. Acad. Sci. USA, Vol. 77, pp. 6851-6855 (1980).
The present invention is an improvement over the two-step hybridization technique, also called the sandwich hybridization technique, described by Dunn and Hassell in Cell, Vol. 12, pp. 23-36 (1977). The sandwich hybridization test described by Dunn et al. is a true two-step hybridization test necessitating two separate hybridization steps. A first hybridization occurs between the nucleic acid affixed onto the solid support and the sample nucleic acid, followed by extensive washing of the solid support. A second hybridization occurs between the washed nucleic acid on the support and a radioactive nucleic acid probe.
The two-step sandwich technique has been used for studying nucleic acids which are inherently single-stranded, that is RNA or single-stranded DNA. If the nucleic acids are double-stranded or double-stranded having been rendered single-stranded, the presence of complementary strands results in the annealing of the nucleic acids, thereby at least partially preventing the hybridization of the labelled probe in the second hybridization step. The present invention avoids the drawbacks of the two-step sandwich hybridization technique by employing a competitive one-step sandwich hybridization technique. Because of this fact the one-step sandwich hybridization technique is more sensitive than the two-step sandwich hybridization technique. Furthermore, it is more rapid to perform and requires less hybridization mixture and washing solution. Consequently the one-step sandwich hybridization technique is more suitable for routine diagnostics.
SUMMARY OF THE INVENTION
A highly sensitive one-step sandwich hybridization technique has been developed for the detection of nucleic acids. A given microbe or microbial group can be detected from a crude sample by its double-stranded or single-stranded nucleic acids. One-step sandwich hybridization requires the simultaneous addition of two purified nucleic acid reagents for each microbe or group of microbes to be identified. The reagents are two distinct single-stranded nucleic acid fragments isolated from the genome of the microbe to be identified, which fragments have no extensive sequence homology in common (i.e. do not cross-hybridize) but preferably are situated close together in the genome and are produced by using the established recombinant DNA techniques. One of the nucleic acid fragments is affixed onto a solid carrier, preferably a nitrocellulose filter, and the other fragment, also in single-stranded form, is labelled with a suitable label. After the sample nucleic acids to be identified are rendered single-stranded, they are contacted with single-stranded nucleic acid reagents. Annealing of complementary base pairs results in the formation of double-stranded hybrids, i.e. nucleic acid sample/labelled reagent and nucleic acid sample/reagent affixed to solid carrier.
The invention encompasses nucleic acid fragments prepared by conventional vectors, hosts, ligases, transcriptases and cultivation and separation procedures. Typical vectors are plasmids, cosmids and bacteriophages, such as the plasmids pBR322, pUB110, λ-phage and bacteriophage M13 mp 7. It is particularly useful to employ two separate vectors, one for the solid carrier affixed nucleic acid reagent and another for the labelled nucleic acid reagent in order to avoid the occurrence of residual vector sequences, thereby minimizing hydridization background. It is preferred to produce the fragments by using restriction enzymes such as BamHI, Pst I, EcoRI and XhoI. Representative nucleic acid fragments contain a range of base pairs from at least 10 base pairs to several thousand base pairs. Nucleic acid fragments of 300 to 4000 base pairs are preferred. The length of the fragments are relatively unimportant so long as the fragments can cross-hybridize with the sample nucleic acid to form stable hybrids.
Once nucleic acid fragments have been prepared, nucleic acid fragments are affixed to a solid carrier. Suitable solid carriers are nitrocellulose sheets or conventional modified paper, such as nitrobenzoyloxymethyl paper or diazobenzyloxymethyl paper as described by Wahl et al. in U.S. Pat. No. 4,302,204 or aminobenzoyloxymethyl paper described by Rabbini et al. in U.S. Pat. No. 4,139,346. Nylon membranes and modified nitrocellulose might be used as well. The only limitations on the solid carrier is that it must be capable of affixing nucleic acids in single-stranded form such that the single-stranded nucleic acids are available to hybridize with complementary nucleic acids and that the carrier can be easily removed from the hybridization mixture.
Nucleic acid fragments are labelled with radioisotopes, such as 125 I and 32 P, fluorochromes, chromogens and enzymes. Lanthanide chelates detected by delayed fluorescence and described in U.S. Pat. No. 4,374,120 and U.S. Pat. No. 4,374,120 are suitable labels, as well as the biotin-avidine labels described by J. J. Leary, et al. in P.N.A.S., Vol. 80, pp. 4045-4049 (1983). When a radioactive label is used, it is preferred to use one with specific activity of 10 7 to 10 9 cpm/μg DNA.
The kit described in this invention can in principle be used for the identification of DNA- or RNA-containing organisms, such as viruses, bacteria, fungi and yeasts. The kit has the specific advantage of simultaneously detecting specific bacteria anf viruses from a mixed sample regardless of whether the microbes contain DNA or RNA. By suitable combination of reagents it is possible to develop kits such that each microbe to be identified has its own specific solid carrier and labelled nucleic acid reagent. All the filters included in the reagent combination can be added to the sample simultaneously, along with the labelled nucleic acid reagents. When hybridization has taken place, the solid carriers are washed and their labelling is measured. The technique is highly sensitive.
Kits of this invention can be used, e.g. in medical microbiology, veterinary microbiology and food hygiene investigations and microbial diagnostics of plant diseases. Suitable sample materials are animal and plant tissue homogenates, blood, feces and nasal and urethral mucous. It can be estimated that the kit is sufficiently sensitive to detect microbe levels normally present in clinical samples. Preliminary enrichment of the microbe present in the sample by cultivation is of course possible before the identification test and in some cases would be essential. The kit is also suitable for the investigation of samples from which the microbe can no longer be cultivated but which contain considerably amounts of microbial debris (e.g. after the commencement of antibiotic treatment), or when cultivation of the microbe is particularly laborious and difficult (e.g. anaerobic bacteria, which are present in large numbers in suppurative samples in the case of infections caused by anaerobes).
Representative kits of the invention can be used to detect the nucleic acid(s) present in the following:
Respiratory infections:
(a) Bacteria: β-hemolytic streptococci (group A), Hemophilus influenzae, pneumococci, Mycoplasma pneumoniae, mycobacteria
(b) Viruses: influenza A, influenza B, parainfluenza (types 1, 2 and 3), respiratory syncytial virus, adenoviruses, coronaviruses, rhinoviruses
Diarrhoeas:
(a) Bacteria: salmonellae, shigellae, Yersinia enterocolitica, enterotoxigenic, E. coli, Clostridium difficile, campylobacter
(b) Viruses: rotaviruses, parvoviruses, adenoviruses, enteroviruses
Venereal diseases:
(a) Bacteria: Neisseria gonorrhoeae, Treponema pallidum, Chlamydia trachomatis
(b) Viruses: Herpes simplex virus
(c) Yeasts: Candida albicans
(d) Protozoa: Trichomonas vaginalis
Sepsis:
(a) Bacteria: β-hemolytic streptococci (group A), pneumocci, enterobacteria
Food hygiene:
(a) Bacteria: salmonellae and Clostridium perfringens.
The specificity of the diagnostic kit can be limited to a defined microbial group (e.g. salmonella bacteria) or broadened to a wider microbial group (e.g. enterobacteriaceae) by selecting particular nucleic acid fragments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The nucleic acid reagents required in the one-step sandwich hybridization technique are produced by recombinant DNA technology. The recombinant plasmids used as nucleic acid reagents in the one-step hybridization technique of this invention are cloned into the host Escherichia coli K12 HB 101. Deposits of recombinant plasmids have been made in the Deutsche Sammlung von Mikroorganismen (DSM), Grisebachstrasse 8, D-3400 Goettingen, Germany (Federal Republic) and in the National Public Health Institute (KTL), Mannerheimintie 166, Helsinki, Finland. The deposit numbers are as follows:
______________________________________Plasmid DSM KTL______________________________________pKTH1201 DSM 2823 EH 231 (KTL)pKTH1201 DSM 2824 EH 230 (KTL)pKTH45 DSM 2821 EH 254 (KTL)pKTH312 DSM 2822 EH 232 (KTL)______________________________________
The recombinant phage mKTH 1207 was deposited at DSM and KTL under deposit numbers, DSM 2828 and EH 256 (KTL), respectively. The following describes the reagent production and test procedures for Example 1.
Reagents
Adenovirus type 2 (Ad 2 ) (ATCC VR-846) was obtained from KTL, the National Public Health Laboratory located in Helsinki, Finland. Ad 2 was cultivated and purified and its DNA was isolated in accordance with the procedure set forth by Petterson and Sambrook in the Journal of Molecular Biology, Vol. 73, pp. 125-130 (1973). The DNA was digested with BamHI-restriction enzyme obtained from Bethesda Research Laboratories (BRL), which enzyme cuts the DNA into four reproducible fragments. Two of these fragments were inserted into the BamHI-site of the vector plasmid pBR322 (BRL) with the aid of T4-ligase (BRL). The fragments were not separated before ligation, but the insert was in each case identified only after cloning. The bacterial host, E. coli HB101 (K12) gal - , pro - , leu - , hrs - , hrm - , recA, str R , F - , obtained from KTL, was transformed with the plasmid DNA composed of recombinant plasmids, i.e. molecules which had accepted fragments of the adenovirus DNA, by the procedure set forth in Cohen et al. in Proc. Natl. Acad. Sci. USA, Vol. 69, pp. 2110-2114 (1972).
Bacterial clones which contained recombinant plasmids were chosen. Ampicillin and tetracycline resistance were transferred to the bacterium by the pBR322-plasmid (Bolivar et al., Gene, Vol. 2, pp. 95-113 (1977)). Bacteria containing the recombinant plasmid were sensitive to tetracycline, because the BamHI-restriction site was within the tetracycline gene and the foreign DNA inserted into this region destroyed the gene. The insert of the plasmid was characterized after plasmid enrichment by determining the size of the restriction fragments after BamHI digestion using agarose gel electrophoresis. Adjacent BamHI D- and C-fragments of the Ad 2 -DNA were chosen as reagents (Soderlund et al., Cell, Vol. 7, pp. 585-593 (1976).
The preferred recombinant plasmids, Ad 2 C-pBR322 or pKTH1201, assigned deposit No. DSM 2823 at the DSM and deposit No. EH231 at the KTL, and Ad 2 D-pBR322 or pKTH 1202, assigned deposit No. DSM 2824 at the DSM and deposit No. EH230 at the KTL, were cultivated and purified by conventional methods, see for example Clewell and Helinski in Proc. Natl. Acad. Sci. USA, Vol. 62, pp. 1159-1166 (1969).
The recombinant plasmid Ad 2 D-pBR322 was used as the filter reagent. It was not necessary for purposes of the invention to remove the plasmid sequences. However, for the radioactive labelling, the nucleic acid was separated from pBR322-DNA after BamHI-digestion with the aid of agarose gel electrophoresis. The C-fragment was isolated from LGT-agarose (Marine Colloids, Inc.) by phenol extraction or electro-elution (Wieslander, Anal. Biochem., Vol. 98, pp. 305-309 (1979) and concentrated by ethanol precipitation.
It was particularly expedient to subclone the nucleic acid fragment chosen for labelling in a separate vector, in order to avoid the hybridization background resulting from the direct hybridization with the filter of the residual plasmid sequences, contaminating the labelled nucleic acid reagent. The single-stranded DNA-phage M13 mp7 (BRL) could be used as an optimal vector (Messing et al., Nucleic Acids Research, Vol. 9, pp. 309-323 (1981)).
Attachment of DNA to the filter
The recombinant plasmid Ad 2 D-pBR322 was denatured to a single-stranded form and nicked randomly at several sites by treatment with 0.2N NaOH for 5 minutes at 100° C., whereafter the DNA was chilled and, immediately prior to transference to the filter, neutralized and pipetted to the transfer solution, 4×SSC medium on ice (SSC=0.15M NaCl, 0.015M Na-citrate). The filters (Schleicher and Schull BA85 nitrocellulose) were thoroughly wetted in 4×SSC solution for about 2 hours before the application of DNA. The DNA was attached to the filter in a dilute solution (0.5-1.0 μg/ml) by sucking the solution through the filter in a weak vacuum. The filter was capable of absorbing DNA up to about 180 μg/cm 2 (see Kafatos et al., Nucleic Acids Research, Vol. 7, pp. 1541-1552 (1979)). DNA concentrations of between 0.5 μg DNA/2.5 cm diameter of filter and 1.0 μg DNA/0.7 cm diameter of filter were used. After DNA filtration the filters were washed in 4×SSC, dried at room temperature and finally baked in a vacuum oven at 80° C. for 2 hours. Since the DNA on the filters was stable, the filters were stored for long periods at room temperature (Southern, Journal of Molecular Biology, Vol. 98, pp. 503-517 (1975)).
Labelling of the radioactive nucleic acid fragment
The radioactive label used was the 125 I-isotope, which was quantitated by gamma counters. Since the half-life of the isotope is 60 days, the utilization period of 125 I-labelled reagents is about 4 months.
"Nick-translation" labelling
This method displaces one of the nucleotides in the nucleic acid with a radioactive one, whereby upon replication the whole DNA molecule is labelled. This was carried out according to the method published by Rigby et al. in the Journal of Molecular Biology, Vol. 113, pp. 237-251 (1977). The DNA was labelled in a solution containing a 125 I-labelled deoxynucleoside triphosphate such as 125 I-dCTP (Radiochemical Centre, Amersham: >1500 Ci/mmol) as substrate. Under optimal conditions a specific activity of 10 9 cpm/μg DNA was obtained. The labelled DNA was purified from nucleotides remaining in the reaction mixture by simple gel filtration, e.g. using BioGel P30 (BioRad).
Other labelling methods
The single-stranded nucleic acid reagent produced in M13 mp7-phage was labelled by chemical iodination, in which the reactive 125 I was added covalently to the nucleic acid (see Commerford, Biochemistry, Vol. 10, pp. 1993-2000 (1971) and Orosz et al., Biochemistry, Vol. 13, pp. 5467-5473 (1974)). Alternatively, the nucleic acid was made radioactive by end-labelling with radioactive nucleotides by the terminal transferase (see Roychoudhury et al., Methods of Enzymology, Vol. 65, pp. 43-62 (1980)).
Reagents for microorganisms containing RNA
The reagent preparation described above has related to microbes whose genetic material is in the form of DNA. In the case of RNA viruses, the cloning of genome fragments took place after a DNA copy (cDNA) of the virus RNA was made with the aid of reverse transcriptase, followed by DNA-polymerase, to copy the second DNA strand, therafter the DNA was cloned as described above (see Salser, Genetic Engineering, Ed. Chakrabarty, CRC Press, pp. 53-81 (1979)).
The most suitable cloning method is chosen depending on the microbe used. The hosts as well as the vectors vary. For example, vector possibilities include the λ-phage, other plasmids, cosmids, cloning e.g. in bacterial hosts such as Bacillus subtilis and Escherichia coli (Recombinant DNA, Benchmark Papers in Microbiology, Vol. 15, Eds. Denniston and Enqvist, Dowden, Hutchinson and Ross, Inc. (1981) and Ish-Horowicz et al., Nucleic Acids Research, Vol. 9, pp. 2989-2998 (1981)).
Performance of the test
Sample treatment
The nucleic acid to be identified is released from a microbe or from infected cells by mechanical or chemical (lysozyme and EDTA) means. Virus genomes are isolated, for example, by treating the viral sample with 1% sodium dodecylsulphate (SDS). The proteins which protect the viral genome are removed by conventional procedures, for example, by proteinase K treatment (1 mg/ml, 37° C., 60 minutes). If the sample contained larged quantities of viscous high molecular weight cellular DNA, the cellular DNA is sheared by sonication or by passing it through a fine needle.
Hybridization
The nucleic acids of the sample are rendered single-stranded by boiling for about 5 minutes and quick cooling at 0° C. A hybridization mixture is added to the denatured nucleic acid sample and this mixture is pipetted onto a solid carrier, e.g. a nitrocellulose filter, in the hybridization vessel. There are many hybridization mixtures which are suitable for one-step sandwich hydridization; see the hybridization mixtures described by Denhardt in Biochem. Biophys. Research Communications, Vol. 23, pp. 641-646 (1966) and by Wahl et al. in U.S. Pat. No. 4,302,204. A representative hybridization mixture is 50% formamide (deionized, stored at -20° C.) in a 4×SSC with Denhardt solution, containing 1% SDS and 0.5 mg/ml DNA (salmon sperm or calf thymus). The single-stranded nucleic acid hybridizes with a combination of purified nucleic acid reagents, one of which is labelled and one of which is affixed to a solid carrier. Hybridization occurs in a single step and typically at a temperature of 37° C. over a period of 16-20 hours.
Washing
After hybridization has taken place, the solid carrier is removed from the hybridization vessel and carefully washed by a dilute SSC solution, preferably 0.1×SSC. It is essential that the washing solution contains SDS to inhibit any nuclease activity of the sample.
Measuring
The amount of radioactive label remaining on the washed carrier is measured by conventional methods, e.g. a scintillation or a gamma-counter. An alternative method for measuring radioactivity is autoradiography. If fluorescent or enzymatic labels are employed, they are measured by numerous conventional methods.
Background is measured by the use of suitable controls, i.e. a solid carrier containing no nucleic acid at all, a solid carrier containing thymus nucleic acid or some other indifferent nucleic acid, and a solid carrier containing all relevant reagents but no sample nucleic acids.
The invention is illustrated by the following examples:
EXAMPLE 1
The sandwich hybridization method in accordance with the invention detected viral DNA in a solution as well as viral DNA in infected cells.
HeLa cells were infected with type 2 adenovirus. The cells were then disrupted by treatment with 1% SDS, followed by digestion with 1 mg/ml proteinase K enzyme (Sigma) for 30 minutes at 37° C. Before denaturation the sample was passed through a fine needle. For the details concerning the filters, nucleic acid reagents and hybridization, refer to the text of Table 1.
TABLE 1______________________________________ Filters (cpm) Adeno(1) Calf thymus(2) Blank(3)______________________________________SamplesAdenovirus type 2 DNA 9000 49 --(BRL) (500 ng)HeLa cells (6 × 10.sup.5) 8200 -- --infected with adenovirusFilters:(1) Ad.sub.2 D-pBR322-plasmid, 2 μg(2) Calf thymus DNA 1 μg (Boehringer Mannheim)(3) Blank (no DNA)Labelled nucleic acid reagent:Ad.sub.2 -BamHI C-fragment, purified, specific activity 90 ×10.sup.6cpm/μg (200000 cpm .sup.125 I/reaction)Hybridization:50% formamide, 4 × SSC, Denhardt solution, containing 0.5mg/ml salmon sperm DNA and 1% SDS for 16 hours at 37° C.Washing:0.1 × SSC for 40 minutes at room temperature______________________________________
Adenovirus DNA fragments hybridized to adenovirus type 2 DNA and to adenovirus DNA from HeLa cells infected with adenovirus as shown in the above Table 1. The hybridization background radiation was measured in a tube containing only the filter and the labelled nucleic acid reagent, without the sample. The background radiation came from the pBR322 sequences which occurred in the labelled nucleic acid reagent. These sequences hybridized directly with the filter without the mediation of the sample. The filters containing calf thymus and no DNA were used in the test as controls, indicating on the one hand the specificity of hybridization and on the other the level of the nonspecific background radiation arising, e.g. from insufficient washing. The values appearing in Table 1 were corrected by subtraction of the reagent background, obtained by carrying out a similar hybridization but without sample. The background due to the reagents was subtracted from the cpm-values hybridized to the filters.
EXAMPLE 2
The sandwich hybridization method in accordance with the invention detected viral RNA in solution and in infected cells.
The model single-stranded RNA-virus used was the Semliki Forest virus, prototype strain, obtained from the London School of Hygiene and Tropical Medicine. Using the virus genome as a template cDNA was produced, which was cloned into the pstI site of pBR322 plasmid as described by Garoff et al. in Proc. Natl. Acad. Sci. USA, Vol. 77, pp. 6376-6380 (1980). The recombinant plasmid, called pKTH312, was deposited at DSM under the deposit No. DSM 2822 and at KTL under deposit No. EH 232. The insert of this plasmid, originating from the virus genome, is about 1400 nucleotides long, and is derived from the structural protein area, approximately from nucleotide 200 to nucleotide 1600. The whole recombinant plasmid pKTH312 was linearized with EcoRI restriction enzyme (BRL) since the sequence originating from the Semliki Forest virus did not contain recognition sites for the EcoRI-enzyme. The linearized plasmid was cut into two fragments using XhoI-enzyme (BRL). The restriction site of the latter was located within the Semliki Forest virus sequence. The larger EcoRI-XhoI-fragment A (about 3900 base pairs) was attached to the filter and the smaller fragment B (about 1850 base pairs) was labelled with 125 I using the nick-translation technique.
BHK-21 cells were infected with Semliki Forest virus. Semliki Forest virus (30 μg) was disrupted with SDS before the test. The infected cells were handled as described in Table 1.
TABLE 2______________________________________ Filters (cpm) Semliki Forest virus(1) Calf thymus(2) Blank(3)______________________________________SamplesSemliki Forest 3340 -- 33virus 30 μgCells infected with 2698 8 10Semliki Forest virus(5 × 10.sup.5)Non-infected cells 10 5 8Filters:(1) EcoRI-XhoI-fragment A (1.2 μg) of the pKTH312 plasmid(2) Calf thymus DNA 1 μg(3) Blank (no DNA)Labelled nucleic acid reagents:EcoRI-XhoI-fragment B of the plasmid pKTH312, specific activ-ity 90 × 10.sup.6 cpm/μg DNA (200,000 cpm .sup.125 I/reaction).Hybridization:See text of Table 1.Washing:See text of Table 1.______________________________________
Semliki Forest virus specific fragments hybridized to Semliki Forest virus RNA and to Semliki Forest virus RNA from the BHK-21 cells infected with Semliki Forest virus as shown in the above Table 2. The values given in the table have been corrected for reagent background, obtained from a similar hybridization without sample.
EXAMPLE 3
Viral messenger RNA was detected in solution and in infected cells with the aid of the sandwich hybridization method.
The filter hybridization reagents were produced from SV40-virus DNA (BRL) by cutting the DNA into two parts using PstI-enzyme (Boehringer Mannheim) as described by Lebowitz and Weissman in Current Topics in Microbiol. Immunol., Vol. 87, pp. 43-172 and the fragments were isolated and purified by agarose gel electrophoresis. Fragment A (4000 base pairs) was radioactively labelled with 125 I by nick-translation and fragment B (1220 base pairs) was attached to the filter.
The DNA fragments were chosen so that each contained areas coding for both early and late messengers. Thus fragment B contained about 700 bases from the structural protein gene VP1 and over 600 bases from the gene for early messengers. Because the DNA of SV40 virus is in itself a covalently closed ring, it cannot be detected by the test before linearization. Therefore, when infected cells were used as the sample it was possible to test how well the method was adaptable to the detection of RNA copies of the viral genome. As can be seen from the results in Table 3, the test was excellently suited to the investigation of infected cells. The table also demonstrated that the same reagents could be used to investigate both the viral DNA and mRNA made from it.
SV40-virus DNA (BRL) was linearized with EcoRI restriction enzyme (BRL). CV1-cells (Biomedical Centre, Upsala University) were infected with SV40-virus (obtained from Chou and Martini, NIH, Bethesda) and the cells were harvested 40 hours after infection. Treatment of the sample was as described in Table 1.
TABLE 3______________________________________ Filters (cpm) SV40(1) Calf thymus(2) Blank(3)______________________________________SamplesTest 1SV40 viral DNA (50 ng) 20061 159 104(linearized)No sample -- -- --Test 2CVI-cells infected with 30814 294 580SV40-virus 40 hoursafter infection (10.sup.6cells)Non-infected cells -- -- --Filters:(1) The shorter fragment PstI B (0.2 μg) of the circular SV40-virus DNA digested with PstI-restriction enzyme(2) Calf thymus DNA 1 μg(3) Blank (no DNA)Labelled nucleic acid reagent:The longer PstI A-fragment of the SV40-virus DNA, specificactivity 28 × 10.sup.6 cpm/μg DNA (200,000 cpm.sup.125 I/reaction)Hybridization:See text of Table 1. The time for the hybridization was 40hours.Washing:See text of Table 1.______________________________________
SV40 fragments hybridized to SV40 viral DNA and to viral nucleic acids from CV1-cells infected with SV40 virus as shown in Table 3. The values presented in the table have been corrected for reagent background, obtained from a similar hybridization carried out without sample.
EXAMPLE 4
Bacillus amyloliquefaciens was detected by sandwich hybridization.
The reagents were fragments of the α-amylase gene of B. amyloliquefaciens E18 (Technical Research Centre of Finland, VTT), which were isolated for the purpose of this test from the recombinant plasmid pKTH10 (see Palva et al., Gene, Vol. 15, pp. 43-51 (1981)) by treatment with restriction enzyme and subsequent agarose gel electrophoresis. The fragments used for this test were the ClaI-EcoRI fragment (460 base pairs) (ClaI Boehringer Mannheim) and the EcoRI-BamHI fragment (1500 base pairs). The EcoRI-BamHI fragment was attached to the filter and the ClaI-EcoRI fragment was labelled with 125 I by nick-translation.
Bacterial samples were treated with lysozyme (67 μg/ml) for 30 minutes at 37° C. and 5 mM EDTA was added to the E. coli samples. SDS was added to all the samples (final concentration 2%) and the samples were passed twice through a fine needle to reduce their viscosity before being denatured by boiling as described in the text relating to handling of samples.
As can be seen from Table 4, the B. amyloliquefaciens was identifiable by sandwich hybridization on the basis of the single α-amylase gene. E. coli gave a result in this test which was indistinguishable from the background.
TABLE 4______________________________________ Filters (cpm) α-amylase(1) Calf thymus(2) Blank(3)______________________________________SamplespKTH10-plasmid-DNA 5773 47 --(linearized) 1 μgNo sample -- -- --E. coli HB101 (10.sup.9) -- -- --Bacillus amylolique- 3377 -- --faciens (3 × 10.sup.9)Bacillus amylolique- 2871 -- --faciens (10.sup.9)Filters:(1) The EcoRI-BamHI fragment of the α-amylase gene from plasmid pKTH10, 0.35 μg(2) Calf thymus DNA, 1 μg(3) Blank (no DNA)Labelled nucleic acid reagent:The ClaI-EcoRI fragment of the α-amylase gene from plasmidpKTH10, specific activity 35 × 10.sup.6 cpm/μg (200,000 cpm.sup.125 I/reaction)Hybridization:See text of Table 1.Washing:See text of Table 1.______________________________________
The values appearing in the table have been corrected for reagent background, obtained from a similar hybridization without sample.
EXAMPLE 5
A reagent combination kit in accordance with the invention detected specific viral and bacterial nucleic acids in a given sample.
The samples investigated in this test were cells infected by three viruses (adenovirus, SV40 virus and Herpex simplex virus) and a sample containing Bacillus amyloliquefaciens bacteria. As shown in Table 5, the following reagents were all simultaneously added to each sample: 5 filters, each containing one type of DNA from SV40 virus, adenovirus, Bacillus amyloliquefaciens, α-amylase gene and calf thymus, a filter containing no DNA at all, and 200,000 cpm of each of the following labelled nucleic acid reagents: SV40 virus, adenovirus and α-amylase gene DNA reagent.
Cell samples infected with SV40 virus and adenovirus have been described in Tables 3 and 1, respectively. 10 6 Vero cells were infected with Herpes simplex virus type 1. The cells were harvested 20 hours post infection when cytopathic effect was observed.
TABLE 5______________________________________ Filters (cpm) SV40 Adeno α-amylase Calf Blank (1) (2) (3) thymus(4) (5)______________________________________SamplesCells infected 18390 2 13 22 31with SV40 virus(10.sup.6)Cells infected -- 8750 5 13 --with adenovirustype 2 (6 × 10.sup.5)Cells infected -- -- -- 5 13with Herpexsimplex virus(10.sup.6)Bacillus 15 8 6500 16 5amylolique-faciens (10.sup.9)Non-infected -- -- -- -- --cellsFilters:(1) See Table 3.(2) See Table 1.(3) See Table 4.(4) Calf thymus DNA, 1 μg(5) Blank (no DNA)Labelled nucleic acid reagents:SV40 virus as in Table 3Adenovirus as in Table 1α-amylase gene as in Table 4Hybridization:See text of Table 1.Washing:See text of Table 1.______________________________________
Table 5 has shown that it is possible, without division or dilution of the sample, to investigate simultaneously a series of microbes by adding a suitable reagent combination to the sample. The filters were recognized by a sign such as a mark or tag, which identified the sequence it contained.
The values in the table were corrected for reagent background, obtained by carrying out a similar hybridization without sample.
EXAMPLE 6
DNA was detected in purified E. coli DNA samples and in disrupted E. coli cells by the sandwich hybridization method in accordance with the invention.
DNA from E. coli K12 HB101 was isolated according to the method described by Marmur in the Journal Molecular Biology, Vol. 3, pp. 208-218 (1961). The DNA was denaturated by treating with 7 mM NaOH at 100° C. for 5 min.
The E. Coli cells were treated with the following solutions: 500 μg/ml lysozyme, 70 mM EDTA at 37° C. for 30 min. and 0.25% SDS at +65° C. The free DNA was denaturated by boiling in 14 mM NaOH at +100° C. for 5 min.
The reagents were prepared from the outer membrane protein A-gene of Escherichia coli, called the ompA-gene. The hybrid plasmids pKTH40 and pKTH45, used as the starting materials, were prepared from the pTU100 plasmid described by Henning et al. in Proc. Natl. Acad. Sci. USA, Vol. 76, pp. 4360-4364 (1979).
The plasmid pKTH45 was deposited under deposit No. DSM 2821 at DSM and under deposit No. EH254 at the KTL in Helsinki, Finland. This plasmid was attached to the filter. It contained 740 base pairs from the 5'-terminal end of the ompA-gene inserted into the pBR322-plasmid.
The plasmid pKTH40 contained 300 base pairs from the 3'-terminal end of the ompA-gene and the immediately following 1400 base pairs from the genome of E. coli. The pKTH40 plasmid was cleaved with the BamHI restriction enzyme to retrieve the DNA fragment of E. coli, which contained the 1700 base pairs mentioned above. This fragment was transferred to the single-stranded bacteriophage M13mp7 in accordance with the conventional methods, see for example Messing et al. in Nucleic Acids Research, Vol. 9, pp. 309-321 (1981), Heidecker et al. in Gene, Vol. 10, pp. 69-73 (1980) and Gardner et al. in Nucleic Acids Research, Vol. 9, pp. 2871-2888 (1981).
The recombination-phage mKTH1207 was deposited under deposit No. DSM 2828 at DSM and under deposit No. EH256 at the KTL. This recombination-phage was labelled with an 125 I-isotope as described under the heading "Other labelling methods" and was used as a probe in the sandwich hybridization method.
As shown in Table 6, the E. coli was identifiable by sandwich hybridization on the basis of the outer membrane protein A-gene.
TABLE 6______________________________________ Filters (cpm) ompA(1) Calf thymus(2) Blank(3)______________________________________SamplesE. coli K12 HB101 DNA 282 -- --(a) 2 × 10.sup.7E. coli K12 HB101 DNA 2206 -- --(a) 2 × 10.sup.8E. coli K12 HB101 cells 1113 -- --(b) 2 × 10.sup.7E. coli K12 HB101 cells 2327 12 5(b) 2 × 10.sup.8(a) number of DNA-molecules(b) number of cellsFilters:(1) pKTH45 plasmid 1.088 μg (2 × 10.sup.11 molecules)(2) Calf thymus DNA 1.088 μg(3) Blank (no DNA)Labelled nucleic acid reagent:mKTH1207, specific activity 8 × 10.sup.7 cpm/μg DNA(200,000 cpm/reaction)Hybridization:4 × SSC, 1 × Denhardt solution without BSA (bovine serumalbumin), containing 200 μg/ml Herring sperm DNA and 0.25%SDS, at +65° C. for 17.5 hoursWashing:See text of Table 1.______________________________________
The values presented in the table have been corrected for reagent background, obtained from a similar hybridization without sample.
EXAMPLE 7
Two studies (A and B) were conducted to compare one-step sandwich hybridization with two-step sandwich hybridization.
The reagents used were adenospecific filters containing 0.4 μg DNA, control filters containing calf thymus DNA or no DNA, adenospecific probes having a specific activity of 10 8 cpm/μg, (200,000 cpm/reaction), and adenovirus type 2 DNA (0.2 ng, 0.5 ng, 1 ng and 2 ng) to be used as the sample DNA. The hybridization mixture contained 6×SSC, 0.02% Ficoll and 0.02% polyvinylpyrrolidone, 0.2% SDS and 200 μg/ml of denatured herring sperm DNA. The hybridization was carried out at a temperature of 65° C. for a period of 20 hours, whereupon the filters were washed with a solution (50° C.) of 0.1×SSC containing 0.2% SDS for a period of 2 hours. The radioactivity was quantitated by a Wallac Compugamma counter.
In the Study A, the one-step sandwich hybridization was carried out under the conditions described above by simultaneously incubating the sample DNA with the adenospecific filters and with the probe DNA. In the Study B, the first-step of the two-step sandwich hybridization was carried out by incubating the sample DNA with the adenospecific filters. After the initial 20 hour incubation period and subsequent washing of the filters, the second-step of the two-step sandwich hybridization was carried out by incubating the washed filters with the probe DNA. After a 20 hour incubation period, the filters were washed and counted.
The results of Studies A and B are set forth as follows:
______________________________________Sample cpm incorporatedAdeno-DNA (ng) A B______________________________________0.2 54 20.5 123 331 265 1382 438 310______________________________________
The background reading, that is the radioactivity on the adenospecific filter in a reaction without sample DNA, was 70 cpm. This background reading was substracted from the above values. Values above 50 cpm were positive indicating the presence of adenoviral DNA in the sample.
The sensitivity of Study A (one-step sandwich hybridization) is 0.2 ng, whereas the sensitivity of Study B (two-step sandwich hybridization) is 0.6 ng. In other words, the one-step sandwich hybridization reaction is about three times as sensitive as the two-step sandwich hybridization reaction. The time needed to carry out the one-step sandwich hybridization reaction was a period of 20 hours for hybridization and 2 hours for washing while the time needed to carry out the two-step sandwich hybridization reaction was a period of 20 hours for the first hybridization and 2 hours for washing plus the additional time needed for the second hybridization, that is approximately 20 hours for the second hybridization and 2 hours for washing. This translates into approximately 24 hours additional time. Thus, one-step sandwich hybridization is about two times as fast as the two-step sandwich hybridization. The quantities of reagents, hybridization mixtures and washing solutions were reduced by one-half in the one-step sandwich hybridization reaction.
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This invention relates to a kit for the detection of microbial nucleic acids and a method for identifying the nucleic acids using a one-step sandwich hybridization technique. The technique requires two complementary nucleic acid reagents for each microbe or group of microbes to be identified.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of Provisional Patent Application No. 61/462,290, filed on Jan. 31, 2011 by Brad Karalius and Todd Karalius.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
Not applicable
ABSTRACT OF THE DISCLOSURE
A modular cutting board system comprised of a plurality of cutting boards is disclosed. In this invention, individual cutting boards can be retentively conjoined to other cutting boards of the same or similar make through magnetic holding force, provided by magnetic assemblies disposed in the non-working surface sides of the cutting boards, to produce a larger working surface. The use of magnetic assemblies in place of magnets alone to increase holding force and prevent magnetic interference with steel utensils. Other optional embodiments include rubber gaskets to produce watertight seals and complementary protrusions and recessions to aid in alignment at the conjoining sides. Importantly, this plurality of cutting boards can be easily detached from a conjoined state and into individual cutting boards. This quality of the present invention improves sanitation through easier cleaning and also facilitates storage, compared to large and unwieldy cutting boards.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to kitchenware, specifically to a modular cutting board system. The modular cutting board system is comprised of a plurality of cutting boards where individual cutting boards, all of the same or similar make, can be retentively conjoined together by magnetic force to thereby expand the working surface. The magnetic force is provided by magnetic assemblies and magnetically attractive members disposed in the sides of these cutting boards.
2. Description of Prior Art
Cutting boards are produced in varying sizes that are designed to cater to the size requirements of a specific job. Typically, consumers will purchase various sizes of cutting boards for their kitchens to cover the wide range of tasks performed. Large cutting boards are often needed, but are difficult to clean in small sinks and store in cramped areas. In food industry settings, very large cutting boards are needed and cannot be washed in a sink or dish washer due to their excessively large sizes, thereby compromising sanitation. The present invention seeks to the aforementioned issues by disposing magnetic assemblies in the sides of cutting boards, thereby allowing two or more cutting boards to be conjoined. into a single larger working surface through magnetic assembly-to-magnetic assembly or magnetic assembly-to-steel communication. This feature allows these separate cutting boards to be conjoined using magnetic force. Subsequently, the boards can be detached with ease through the application of physical force in the direction perpendicular to the magnetic communication. This quality of the present invention allows the user to assemble an appropriately-sized working surface to cater to the job at hand. This invention also improves sanitation because large assembled working surfaces can be broken down and cleaned in sinks or dishwashers, as opposed to very large cutting boards that cannot fit in sinks or dishwashers. Additionally, this invention facilitates storage, compared to large and unwieldy cutting boards.
U.S. Pat. No. 6,460,841, issued to Bruce A. Durr, describes cutting boards that may be attached to one another using a rigid connection formed by interlocking keyed tongues and grooves, and includes attachable handles. Additionally, U.S. Pat. No. 4,756,519, issued to Curt L. Lilja, allows for two or more cutting boards to be conjoined through mutually-opposing, vertically-extending recesses and projections, and includes the option of a knife guide attachment. U.S. Pat. No. 6,715,748, issued to Ted Thompson and Mike Neshat, also allows for additional cutting boards to be attached, but does so through structural hinge pins on a non-wooden board, with focus on using the invention for outdoor use. The present invention, however, offers an improvement over the described prior art in that magnetic forces are used as the fastening mechanism instead of unaesthetic tongues, grooves, recesses, projections, or pins. The present invention is also potentially not as susceptible to wear and tear at the conjoining interfaces as the described prior art due to its simplified geometry at the conjoining interfaces.
Magnets have been used in earlier cutting board patents, but their function is entirely different from the administered use intended in the present invention. U.S. Pat. No. 7,125,011, issued to Kevin W. McLaughlin, uses magnet bases attached onto a polymer backing that allows for the cutting boards to be stored on refrigerators. Alternatively, U.S. Patent 20100019430, issued to Ralph J. Ferone, uses magnets to attach a cutting board to a base unit with sufficient spacing between the cutting board and base unit so that a food collection tray may be positioned beneath the cutting board, but does not mention the use of magnets to secure cutting boards directly to one another. Additionally, U.S. Patent 20090014935, issued to Lingdong Zeng, uses magnets for attaching food type-specific cutting board panels atop a base unit. Also, U.S. Patent 20090283952, issued to Jenna Sellers, uses magnets to facilitate holding cutting board panels together in a stacked orientation.
U.S. Pat. No. 4,273,318, issued to Brian H Crowhurst describes a food preparation appliance where a food chopping board is attached by magnetic means to a food tray. Extending from this concept using what Bruce A. Durr teaches in U.S. Pat. No. 6,460,841, someone having ordinary skill in the art could modify Crowhurst's teachings to incorporate Durr's teachings to produce a modular cutting board system that uses magnets in the conjoining mechanism. Importantly, it would take an additional, crucial step to produce what the present invention teaches: to use magnetic assemblies as the conjoining mechanism. This further product feature not only allows for a series of cutting boards to be magnetically conjoined to each other, but effectively replaces larger magnets that would have otherwise been necessary to ensures that the holding force will be sufficiently strong for the task at hand and, in contrast to these larger magnets. minimizes magnetic communication with utensils such as steel knives over the work surface, and finally protects brittle magnets during the conjoining action.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a cutting board system that uses magnetic attraction from magnetic assemblies as the mechanism for conjoining cutting boards to produce a single larger working surface. Magnetic assemblies will focus the magnetic fields on the exposed magnet surfaces so that greater holding strength may be achieved. This feature will also ensure that steel utensils are substantially uninfluenced by the magnets during their operation on the cutting board working surfaces.
Another object of the invention is to allow for the cutting boards to be detached from one another by light-to-moderate physical force so that they may be cleaned and stored with greater ease than a large cutting board.
Another object of the invention is to provide the option of elastomer gaskets attached to one or both sides of the cutting boards to be conjoined, resulting in a potentially watertight seal at the conjoining interface.
Another object of the invention is to provide complementary protrusions and recessions on opposing sides of cutting boards that are to be conjoined so that these cutting boards may be aligned horizontally and vertically when conjoined.
BRIEF SUMMARY OF THE INVENTION
The present invention is a modular cutting board system comprised of a plurality of similar cutting boards that can be conjoined through magnetic force from magnetic assemblies. The magnetic assemblies will be positioned within the non-working surface skies of the cutting boards, on at least one dimension, with their magnetic poles facing outwards from these sides. This invention will allow a person to choose the number of retentive-conjoining-capable cutting boards required for the size of the task at band. In practice, where one cutting board can accomplish a task requiring a small work area, such as, slicing cheese, attaching an additional cutting board or multiple additional cutting boards would enable the preparation of a large serving of food items. Furthermore, this plurality of conjoined cutting boards can be easily detached into individual cutting boards. This quality of the present invention results in easier cleaning of these cutting boards and consequently improved sanitation, as well as easier storage, compared to large and unwieldy cutting boards.
Although many options for magnetic materials exist, magnetic assemblies are used in the present invention for a variety of benefits. Magnetic assemblies, for example a cylindrical magnet contained within a steel cup, commonly referred to as a pot magnet, concentrate magnetic fields on the magnetic assembly surfaces This results in a pull force that is vastly stronger than that of the magnet alone. This feature is crucial because without the use of magnetic assemblies, substantially larger magnets would need to be used, but such larger magnets may not be cost effective, may not fit in the small space allotted for the cutting board conjoining mechanism, and, due to their more dispersed magnetic fields, will dangerously interact with ferromagnetic knives on the cutting board cutting surface. In contrast, magnetic assemblies can reduce the magnetic field strength in the directions towards the working surfaces of the cutting boards. This characteristic can result in a negligible amount of magnetic communication with steel knives that may be used on the cutting board working surfaces. Furthermore, neodymium magnets are preferred in this invention for their superior strength.
Elastomer or plastic gaskets may also but not necessarily be attached to either or both conjoining surfaces of the cutting boards to provide a watertight, or near watertight, seal at this interface. The attachment of these gaskets may be permanent or removable so that they may be removed to be cleaned separately or replaced.
The cutting board sides housing the magnetic assemblies or magnetic assemblies and magnetically attractive members may also but not necessarily feature complementary protrusions and recessions. These complementary protrusions and recessions can act as alignment guides when conjoining the cutting boards together and also hold them together in proper alignment once conjoined.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is an isometric view of two cutting boards, designed in accordance with the claims of the present invention, where complementary pot magnetic assemblies, per their magnetic pole orientations, are positioned along only the dimensionally longer sides of the cutting boards.
FIG. 2 is a side view of two cutting boards, designed in accordance with the claims of the present invention, where complementary pot magnetic assemblies, per their magnetic pole orientations, are positioned along only the dimensionally longer sides of the cutting boards.
FIG. 3 is an isometric view of a pot magnetic assembly, which is one type of magnetic assembly that provides the holding force necessary for conjoining cutting boards described in the present invention.
FIG. 4 is an isometric view of two cutting boards, designed in accordance with the claims of the present invention, where complementary pot magnetic assemblies, per their magnetic pole orientations, are positioned along only the dimensionally longer sides of the cutting boards and gaskets are attached to one of these longer sides of each cutting board.
FIG. 5 is a side view of two cutting boards, designed in accordance with the claims of the present invention, where in the left cutting board two protrusions are featured along the pot magnetic assemblies-containing side of the cutting board. These protrusions aid in the alignment of this cutting board with a second cutting board, shown on the right, possessing both complementary recessions and complementary pot magnetic assemblies when the cutting boards are conjoined.
FIG. 6 is a side view of a two cutting boards, designed in accordance with the claims of the present invention, where complementary sandwich magnetic assemblies, per their magnetic pole orientations, are positioned along only the dimensionally longer sides of the cutting boards.
DETAILED DESCRIPTION OF THE INVENTION
Each cutting board, made out of a food grade material, including wood, wood composite, bamboo, paper composite, rubber, plastic, acrylic, glass, stone or metal. It is preferred that the cutting board material is a structurally stable material, such as edge grain wood panels, bamboo, bamboo plywood, wood composite, paper composite, rubber, plastic, acrylic, glass, stone, or metal because the mechanism for conjoining the cutting boards is dependent upon each cutting board maintaining its original geometry. Each cutting board will also be rectangular or square in shape, with one or more magnetic assemblies disposed in either the non-working surface lengthwise, widthwise, or all sides of the cutting board. The magnetic assemblies will be set at standard distances along the sides of each cutting board so that one cutting board's magnetic assemblies will be aligned with an adjacent cutting board's magnetically attractive members to form a retentive connection between these cutting boards. This connection thereby expands the total working surface. In this arrangement, cutting boards can be connected to each other in either the “x”or “z”dimensions, according to the perspective of a person facing towards a work station.
The magnetically attractive members mentioned above may be oppositely magnetized magnetic assemblies or opposing steel faces. The magnetic assemblies may be positioned approximately flush with the sides in which they are embedded, including being recessed a very small distance from these sides to ensure that the conjoining sides make flush contact before the magnetic assemblies do. Additionally, the magnetic assemblies on a given side of one cutting board may instead be positioned protruding outward from in the side in which they are embedded. The oppositely magnetized magnetic assemblies or opposing steel faces on another cutting board would then be recessed to the same distance as the described protruding magnetic assemblies, or vice versa, to aid in cutting board alignment when conjoining is performed. Alternatively, a given side of a cutting board that contains magnetic assemblies positioned approximately flush to the sides in which they are embedded may instead contain one or more structural protrusions. These protrusions would interact with complementary recesses in the side of another cutting board that contains oppositely magnetized magnetic assemblies or opposing steel faces, also seated approximately flush to the sides in which they are embedded. These features would again aid in cutting board alignment when conjoining is performed because the protrusions and complementary recessions would act as guides to properly align the cutting boards.
FIG. 1 shows an isometric view of two cutting boards that are designed in accordance with the claims and general vision of the present invention. Here, one set of magnetic assemblies with like-poles (e.g. pot magnetic assemblies with north poles as their outer steel ring and south poles as their magnet faces) facing outward ( 1 ) is positioned in one side ( 2 ) of each cutting board. The complementary pair of magnetic assemblies pot magnetic assemblies with south poles as their outer steel ring and north poles as their magnet faces in this scenario) is not visible in this figure. The non-magnetic assembly containing sides ( 3 ) of each cutting board are unimportant towards the functionality of the present invention. The top faces, or bottom faces, of the cutting boards ( 4 ) will serve as the working surfaces for where cutting or food preparation is performed. Importantly, this depiction is Only one visioning of the claims of the resent invention and does not represent the full scope of the claims listed herein.
The mechanism by which these cutting boards described in FIG. 1 may be conjoined offers several benefits over conjoining mechanisms utilized by the prior art. The lack of slots, hives, or other non-magnetic structural locking mechanisms; the cutting boards'sides angled 90 degrees from the working surface faces; and the strength of the magnetic fields projected from the cutting boards'magnetic assemblies will create a near seamless union at the interface between the cutting boards of the present invention. The cutting boards of the present invention also have less potential for wear and tear due to the simple rectangular geometry of these cutting boards. Additionally, there is an aesthetic value to the magnetic conjoining mechanism of the present invention over the prior art because pins, hinges, grooves, cutaway slot, or puzzle-like protrusions are not used.
FIG. 2 shows an enlarged view of how the two cutting boards of FIG. 1 are positioned just prior to conjoining. Here, the side ( 2 ) of the cutting board shown on the left is embedded with the north pole-outer-steel-ring-facing-outward pot magnetic assemblies ( 1 ) flush with that side. The south pole-outer-facing-outward magnetic assemblies are embedded flush in the other side of this cutting board and are not shown in this figure. The second cutting board of the same make is shown on the right and the depicted cutting board side ( 6 ) is embedded with south-pole-outer-steel-ring-facing outward magnetic assemblies ( 5 ). As such, each cutting board will have the capacity to conjoin with any other cutting board of the same or similar make, contingent upon the placement of magnetic assemblies or magnetic assemblies and opposing steel faces along the cutting boards’sides. The depicted slight recessing of magnets in these cutting boards will allow for a flush fit between the cutting boards when conjoined. Importantly, this depiction is only one visioning of the claim of the present invention, and does not represent the full scope of the claims listed herein.
FIG. 3 shows a close-up representation of a pot magnetic assembly ( 1 ) to provide clarity as to how this given magnetic assembly operates. The magnet ( 7 ) here is oriented with its south pole facing outward. The steel cup ( 8 ), which is magnetized by the magnet such that the north pole faces outward, protrudes slightly beyond the magnet. This magnetic assembly achieves a stronger holding force and an overall more concentrated magnetic field than its magnet alone and therefore effectively replaces a larger magnet that would have approximately equal holding force but a more dispersed magnetic field.
FIG. 4 shows an isometric view of two cutting boards, designed in accordance with the claims and general vision of the present invention, where gaskets ( 9 ) are attached to one of the longer sides of each of the cutting boards. The complementary pairs of magnetic assemblies ( 1 and 5 ; 5 not shown) are recessed to a very small degree within the cutting board sides in which they are embedded. This recessing creates a distance gap between the complementary pairs of magnetic assemblies when the cutting boards are conjoined. A potentially watertight seal will be achieved when the cutting boards are conjoined because the complementary pairs of magnetic assemblies will attract each other and pull the cutting boards together, closing the distance gap and compressing the elastomer gasket between the coupled cutting boards. Importantly, this depiction is only one visioning of the claims of the present invention and does not represent the full scope of the claims listed herein.
FIG. 5 shows an enlarged view of two cutting boards and their sides that may be conjoined. The first cutting board, shown on the left, features additional protrusions ( 10 ) from the side ( 2 ) that contains the north-pole-outer-steel-ring-facing-outward magnetic assemblies ( 1 ). The south-pole-outer-steel-ring-facing-outward magnetic assemblies are embedded in the other side of this cutting board and are not shown in this figure; this side also features complementary recessions to these depicted protrusions. The second cutting board of the same make, shown on the right, is instead shown with the cutting board side ( 6 ) that is embedded with south-pole-outer-steel-ring-facing-outward magnetic assemblies ( 5 ). This side features additional recessions ( 11 ) that are complementary in their geometry to the protrusions ( 10 ). These complementary protrusions and recessions are shown as tapered cylinders. This tapering allows for an initial margin of error when bringing the cutting boards together but results in tight alignment once the cutting boards are conjoined. These complementary protrusions and recessions also aid in holding proper alignment of the conjoined cutting boards. Alternatively, complementary concave and convex hemispheres, ridges and troughs, or similar structures may also be used to aid in such alignment. Importantly, this depiction is only one visioning of the claims of the present invention, and does not represent the full scope of the claims listed herein.
FIG. 6 shows an enlarged view of two cutting boards and their sides that may be conjoined, where sandwich magnetic assemblies, instead of pot magnetic assemblies shown in FIG. 1 , are used as the conjoining mechanism. Here, the first cutting board, shown on the left, shows two sandwich magnetic assemblies disposed flush with one side ( 2 ). The near sandwich magnetic assembly ( 13 ) is oriented such that the bar magnet ( 15 ) magnetizes the top steel plate ( 16 )to project the north pole outwards from its face and the bottom steel plate ( 17 ) to project the south pole outwards from its face. The far sandwich magnetic assembly ( 14 ) uses this same construction, except that it is inverted such that the top steel plate projects the south pole outwards from its face ( 17 ) and the bottom steel plate projects the north pole outwards from its face ( 16 ). The second cutting board, shown on the right, also. shows these two sandwich magnetic assemblies disposed flush in one side ( 6 ), but in reverse order where the near sandwich magnetic assembly ( 14 ) has its steel plates magnetized south-over-north due to the inversion of the bar magnet ( 18 ), and the far sandwich magnetic assembly ( 13 ) is magnetized north-over-south. The positioning of these sandwich magnetic assemblies in this side ( 6 ) of the cutting board shown on the right is therefore magnetically complementary to the depicted side ( 2 ) of the cutting board shown on the left and thus these cutting boards are capable of retentively conjoining together. In fact, the side ( 2 ) and its disposed sandwich magnetic assemblies ( 13 , 14 ) shown on the left is the same exact make as the side ( 6 ) with its disposed sandwich magnetic assemblies ( 14 , 13 ) shown on the right and only appears different because it is rotated 180 degrees on the axis that runs parallel with this side. The opposite sides of each of these cutting boards are also of the same make but are not in view in this figure. As such, both cutting boards shown are of the same exact make and only differ in their placement in space. A benefit of this make is that one cutting board can be conjoined to another cutting board lengthwise along their sandwich magnetic assembly-containing sides, regardless of which side ( 2 , 6 ) is chosen and which working surface face ( 4 ) is up or down for each cutting board, as these sides are always magnetically complementary to one another. Importantly, this depiction is only one visioning of the claims of the present invention and does not represent the full scope of the claims listed herein.
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A modular cutting board system comprised of a plurality of cutting boards is disclosed. In this invention, individual cutting boards can be retentively conjoined to other cutting boards of the same or similar make through magnetic holding force, provided by magnets disposed in the non-working surface sides of the cutting boards, to produce a larger working surface. This invention allows for the optional use of magnetic assemblies in place of magnets alone to increase holding force and prevent magnetic interference with steel utensils. Other optional embodiments include rubber gaskets to produce watertight seals and complementary protrusions and recessions to aid in alignment at the conjoining sides. Importantly, this plurality of cutting boards can be easily detached from a conjoined state and into individual cutting boards. This quality of the present invention improves sanitation through easier cleaning and also facilitates storage, compared to large and unwieldy cutting boards.
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SUMMARY
It is a primary object of the present invention to provide a carrier by which a CB radio may be conveniently supported and carried on the body of the user and which includes a portable power pack for supplying electric current to the radio while supported in the carrier.
Another object of the invention is to provide a unit capable of being utilized for converting a CB radio normally mounted in a vehicle into a portable unit which may be carried on the body of a user and powered by an electric source forming a part of the unit.
Still a further object of the invention is to provide such a unit having means for detachably supporting an aerial connected to the CB radio.
Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing illustrating a presently preferred embodiment thereof, and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the power pack and carrier in use;
FIG. 2 is an enlarged fragmentary perspective view of the lower portion of the carrier with the pocket open;
FIG. 3 is an enlarged fragmentary plan view showing the housing of the power pack in an open extended position and with the battery holder removed therefrom, and
FIG. 4 is an enlarged fragmentary vertical sectional view taken through the power pack and showing the aerial mounted thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more specifically to the drawings, the power pack and carrier in its entirety and comprising the invention is designated generally 5 and includes a carrier 6 and a power pack 7.
The carrier 6 includes an elongated shoulder engaging strap 8 having a buckle 9 attached to one end thereof and to which the other end of the strap is detachably and adjustably connected. The strap 8 has a lower portion 10 including complementary side portions 11 each having an upper loop 12 and a lower loop 13. An upper strap 14 extends through the loops 12 and the lower strap 15 extends through the loops 13. A panel or wall member 16 is provided with sleeves 17 at upper and lower ends thereof and on its innerside through which portions of the straps 14 and 15 extend.
Opposite sides of the two end portions of the straps 14 and 15 are provided with VELCRO fasteners 18 by means of which the ends of each strap can be adjustably secured together to combine with the strap portions 11, panel 16, and a portion 19 of the strap 8 which extends between the lower loops 13, to form a pocket 20 having an open upper end 21, formed by the strap 14 and the upper portion of the panel 16, and a closed lower end formed by the strap portion 19.
A conventional CB radio 22, FIG. 1, is positioned against the innerside of the panel 16. The ends of each strap 14 and 15 are then connected together to snugly embrace the radio 22 which is disposed with its back end resting on the strap portion or pocket bottom 19 and with its front end, having the controls 23 and the microphone connection, disposed in or protruding from the open end 21 of the pocket 20. The shoulder strap 8 is then positioned over one shoulder of the user, as illustrated in FIG. 1, and with the strap ends adjusted so that the pocket 20, containing the radio 22, will be located on the other side of the body of the user at approximately the level of the waist. The pocket 20 is disposed so that the panel or wall 16 constitutes the outer or exposed side of the pocket, as clearly illustrated in FIG. 1.
The power pack 7 includes a housing 24 formed in part by the wall member 16. The housing 24 also includes a hood member 25 a part of which is stitched or otherwise secured at 26 to the outer side of the wall member 16 and another, remote part of which has a tab or extension 27 which is detachably connected by another VELCRO fastener 28 to another part of the outer side of the wall 16.
The hood 25 is preferably lined with a sheet of plastic 29. A pair of conventional contact posts 30 are secured in and extend through a wall of the hood 25. The hood 25 contains a conventional battery holder or clip 31 which supports a plurality of conventional dry cell batteries 32 which are connected together in series. Conductors 33 which are connected to inner ends of the posts 30 lead from positive and negative terminals of the clip 31 for connecting the batteries 32 to said posts 30. The clip 31, containing the batteries, is contained in the hood 25 between the wall 16 and a pad 34 of a yieldable foam insulating material which fills the outer part of said hood, as seen in FIG. 4. A spacer member 35 is secured across the outer side of the wall 16 and is disposed in the cavity of the housing 24 to support the battery clip 31 out of contact with the posts 30.
A rigid plate 36 is contained in the outer part of the hood 25, between its outer surface and the lining 29. A rigid bar 37 extends outwardly from the plate 36 through an opening 38 of the hood 25.
A conventional aerial 39 has a bracket 40 forming the base thereof and to which is connected a stationary clamp jaw 41. A spring clamp 42 which is pivotally supported on the bracket 40 has a jaw 43 which is spring urged toward the jaw 41 for clamping the bar 37 therebetween, to mount the aerial 39 detachably on the power pack housing 24, as illustrated in FIGS. 1 and 4. A cable 44, leading from the aerial 39, is connected by its coupling 45 to the conventional aerial connection, not shown, at the rear end of the radio 22. Said coupling 45 extends through an opening 46, FIG. 2, in the strap portion 19. Two conductors 47 from the radio 22 are detachably clamped in the outer ends of the posts 30 to complete the electrical connection between the batteries 32 and the radio 22.
The batteries 32 provide a combined voltage of at least twelve volts for powering the radio 22 which thus functions as a portable transmitting and receiving unit and is supported by the carrier 6 connected to the power pack 24 and aerial 39.
The carrier may be formed of various flexible materials including fabrics, leather and plastic. Other types of fasteners may be substituted for the VELCRO fasteners and various other modifications and changes are contemplated and may be resorted to without departing from the function or scope of the invention.
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A carrier in which CB radios of different sizes can be detachably secured for convenience in carrying. The power pack, consisting of a plurality of dry cell batteries connected together in series and a battery holder forming a part of the carrier, provides a portable power source for the radio. The carrier is constructed to be supported by a part of the body of the user and is provided with means for detachably supporting an aerial connected to the radio.
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This is a continuation of application Ser. No. 193,301, filed Oct. 28, 1971, now abandoned.
RELATED APPLICATIONS
No related applications are copending.
BACKGROUND OF INVENTION
The present invention relates to a system and process for effecting the rapid charging of a battery of sealed storage cells. The present invention also relates to an assembly for permitting the rapid charging of a battery of sealed storage cells comprising a charger and means incorporated in the battery cooperating with the charger to control the latter.
It will readily be understood that a battery of storage cells will satisfy a wider range of application requirements, whether in industrial or in everyday life, if it is capable of being rapidly recharged. The physical problems relating to the rapid charging of sealed storage cells are concerned essentially with the inner pressure of the sealed storage cell and the temperature thereof; an excessively high internal pressure or an excessively high temperature may result in damage to the storage cell. In order not to exceed the safe limiting value permitted for the pressure, it is necessary to know that the charging state of the battery, determined by the value of its charging parameters such as the voltage across the terminals of the storage cell or cells and their temperature. These two charging parameters, i.e. temperature of the storage cell or cells and charging voltage, are not independent; during the final phase of rapid charging, the internal temperature of the storage cell increases, as does also the voltage across the terminals of the battery, and the problem which arises is how to interrupt the rapid charging rate at an opportune instant. This instant should be, on the one hand, sufficiently late to ensure that the battery or cell is either completely charged, or else charged to a sufficient percentage of its total charge and, on the other hand, of course, should be sufficiently timed to ensure that the battery will not be damaged.
Some known processes for the rapid charging of storage cells consist in charging the storage cell at a rapid rate and partially discharging it extremely rapidly and at extremely short intervals during charging, in such manner as to monitor the potential difference across the terminals of the storage cells. In the case of sealed nickel-cadmium storage cells, this known process makes it possible to interrupt high rate charging before the potential of the negative electrode reaches the threshold corresponding to hydrogen evolution. However, the devices for the carrying into effect of these processes are complex and costly. Other processes also have been proposed for the rapid charging of sealed storage cells; for example, one of the said processes, disclosed in French Pat. No. 1,565,095, filed on the 26th Apr. of 1968 in the name of GENERAL ELECTRIC COMPANY, and corresponding to U.S. Pat. No. 3,531,706 consists in charging the battery during every other half-wave, measuring the voltage across the terminals of the storage cells during the other half-wave during which the battery is not being charged, detecting the temperature of the storage cells with the aid of a blade thermistor and, with the aid of a blade switch opening the charging circuit before there is any risk of damage to the cell. The disclosed device of this specification, although it permits rapid charging of sealed storage cells, nevertheless has the disadvantage that it does not afford adequate reproducibility to permit the employment of the same charger for charging a plurality of batteries.
On the other hand, when a rapid charger is connected to the a. c. mains, it is current practice to feed the charger through intermediary of a magnetic leakage transformer or through the intermediary of a conventional transformer and a stabilization inductance. For a charger designed to charge a battery of storage cells of relatively high power, equipment of this kind is heavy and a charger fitted with a transformer represents a weight which renders the utilization thereof inconvenient in practice.
The present invention makes it possible to obviate these disadvantages and provides a rapid-charging device for sealed storage cells which is of great simplicity and has a high degree of reliability. The novel device or system permits the charging of the storage cell or battery during a reduced period of time for obtaining almost complete charging. Furthermore, the device or system is equipped with a slow charging circuit permitting the completion of charge after rapid charging has been halted. The device or system according to the invention comprises means for reliably interrupting rapid charging before the occurrence of any risk of damage to the cell or cells. Finally, according to an embodiment of the invention, the charger is readily transportable due to the elimination of the feed transformer.
BRIEF SUMMARY OF INVENTION
The process according to the invention is characterized in that it comprises: comparing, in permanent fashion, the voltage across the terminals of the battery during, the passage of the rapid-charging or high rate current with a reference voltage which varies in accord with the battery temperature; providing in permanent manner, during the duration of battery charging, a continuous signal which changes its magnitude when the voltage across the terminals of the battery has become higher than the said reference voltage, and is utilized for interrupting the rapid charging when the said signal changes its magnitude.
The invention also relates to an assembly or system for the rapid d. c. type charging of a sealed storage cell or battery of sealed storage cells, characterized in that it comprises: means incorporated in the battery and in thermal contact with the said storage cell or cells for producing a reference voltage varying with the temperature of the storage cell or cells; a charger comprising a rapid charging circuit incorporating a circuit breaker and a circuit for triggering the said circuit breaker, said circuit incorporating a means for permanently comparing the said reference voltage and the voltage across the terminals of the battery during the passage of the rapid charging current, means connected to the comparison means for permanently supplying a continuous signal to the terminals of the said circuit breaker, in such manner as to open the circuit breaker upon change of magnitude of the said continuous signal.
The assembly or system according to the invention has, preferably, one and/or the other of the following features: the said means incorporated in the battery comprises an assembly of series-connected diodes; the said means comprises furthermore an adjusting resistor in series with the assembly of diodes; the said assembly of diodes and the adjusting resistor are connected across the terminals of a Zener diode through intermediary of a resistor in such manner that a constant current flows therethrough during charging; the said battery is furthermore provided with a safety thermostat acting on the said circuit breaker of the said charger.
The invention also relates to a constant-current charger for a sealed storage cell or battery of sealed storage cells characterized in that it comprises a rapid charging circuit incorporating a circuit breaker and a circuit for triggering the said circuit breaker incorporating a means for permanently comparing the voltage across the terminals of the battery with a reference voltage during the passage of rapid charging current, means connected to the said comparison means for permanently supplying a continuous signal to the terminals of the said circuit breaker, in such manner as to open the circuit breaker upon changing of magnitude of the said continuous signal.
According to an advantageous embodiment of the invention, the rapid charger is characterized in that it comprises furthermore, connected in parallel with the rapid charging circuit, a slow charging circuit for charging the battery at the slow rate when the period of rapid charging is terminated.
The charger according to the invention has, preferably, one and/or the other of the following features or characteristics: the said circuit breaker is a thyristor, which is conductive in the rapid charging state and is blocked in the slow charging state; the said comparison means is constituted by a differential amplifier having two transistors comparing the said reference voltage with a fraction of the voltage across the terminals of the battery, obtained by means of a divider bridge; the said fraction of the voltage across the terminals of the battery is obtained by means of a resistive divider bridge and is filtered by means of a condenser; the said means for permanently supplying the said continuous signal is constituted by a transistor connected across the terminals of the circuit of the trigger or gate of the said thyristor and to the said differential amplifier through the intermediary of a two-transistor circuit providing for a clear change of state in the said transistor connected across the terminals of the thyristor trigger; the said transistor is connected across the terminals of the trigger circuit of the said thyristor through intermediary of a capacitor.
According to a further advantageous mode or embodiment, the charger according to the invention is characterized in that it is connected to the a.c. mains through the intermediary of a transformer and a rectifier bridge.
According to a further advantageous mode of embodiment, the charger according to the invention is characterized in that the said thyristor forms part of a power circuit connected to the a.c. mains and comprising, in series with the said thyristor, a monophase rectifier bridge, an inductor and a current regulation circuit and a diode in parallel with the said rectifier bridge and the thyristor. Furthermore in this case, the charger comprises a circuit for exciting the thyristor connected to the said power circuit, comprising a single-junction transistor associated with a transistor circuit varying the angle of excitation of the said thyristor to compensate for the variations in the input voltage of the power circuit, in such manner as to maintain constant the charging current of the battery.
Preferably, the said current-regulating circuit comprises a shunt connected to a differential transistor-type amplifier.
Finally, the invention also relates to a battery of sealed storage cells designed to undergo rapid charging, characterized in that it comprises an assembly of silicon diodes in thermal contact with the storage cells, connected in series and in series with an adjusting resistor, the voltage across the terminals of the diodes and of the adjusting resistor being taken as a reference voltage for service in interrupting rapid charging.
Other objects, features and characteristics of the invention are described hereinbelow, in examples, which are entirely non-limitative, of the assembly according to the invention and with reference to the accompanying drawings, wherein:
FIG. 2 shows plots of the curves of the voltage across the terminals of the cells and of their temperature as a function of time, during rapid charging;
FIG. 2 shows the zone, under voltage, of interruption of rapid charging as a function of the temperature of the storage cells;
FIG. 3 shows a general block wiring diagram of an assembly or system embodying the invention;
FIG. 4 shows the electronic diagram of the assembly or system permitting rapid charging, according to the invention, and
FIGS. 5A and 5B show a variant of the assembly or system also according to the invention.
DETAILED DESCRIPTION
Referring to the drawing, FIG. 1 shows, during rapid charging of sealed storage cells of the type specified, the curves 4 and 5 representing respectively, the voltage across the terminals of the storage cells and their temperature as a function of time. With regard to this selective example, during the first fifty minutes the voltage across the terminals of the element curve 4 exhibits first of all a zone of slow ascent, then a zone or rapid ascent before attaining a maximum, whereafter it decreases. In order to obtain this curve (by way of illustration) the test was voluntarily prolonged, it being understood that it is advisable to interrupt rapid charging approximately at the center of the zone of rapid ascent before attaining the maximum, i.e., in the case of this figure, between 50 and 55 minutes; in fact, when the maximum is attained, there is a risk of exceeding the pressure and temperature safety threshold of the battery and there is a danger that the battery may be damaged.
The curve 5, corresponding to the variations in the temperature as a function of time, also exhibits a zone of relatively slow ascent and a zone of rapid ascent; equally apparent is the necessity to interrupt the rapid charging current in the zone of rapid ascent, corresponding to the similar zone of rapid ascent of the voltage curve 4.
In the diagram of FIG. 2 wherein rapid charging interruption voltage and temperature of the cells are plotted, zone 1 represents the zone of interruption of rapid charging with respect to sealed nickel-cadmium storage cells. It will be noted that zone 1 is located below the curves 2 and 3 representing respectively, the maximum charging voltages which can be attained by the sealed nickel-cadmium storage cells of two types, representing the extreme utilization possiblities, and intended to be charged by a battery charger according to the invention. The cut-off zone 1 indicates at what voltage, for a given temperature, it is necessary to interrupt the rapid charging of the storage cells.
FIGS. 1 and 2 show a certain dependency between the temperature and the voltage of the storage cells. The employment of the two parameters thus tied with each other, i.e. voltage and temperature, is essential for achieving the rapid charging of sealed storage cells and for interrupting rapid charging at the opportune moment.
The assembly according to the invention makes it possible to obtain almost complete charging during an extremely short period of time, less than 1 hour in the case of the example selected. After this period of rapid charging, and as will be set forth hereinbelow, it is possible to complete charging at a slower rate, so as to obtain complete charging.
FIG. 3 shows a block diagram of the assembly or system according to this invention. The block 20 represents the charger according to the invention and the block 19 of the battery of sealed storage cells intended to be charged. Reference numeral 10 represents a source of voltage; in this example, what is concerned is a source of a.c. voltage. The source of voltage 10 is connected to a rectifier device 11. The rapid charging circuit 14 is connected to the rectifier 11 through intermediary of the circuit breaker 12. Reference numerals 15 and 16 designate the terminals of the battery. As a variant, a slow charging circuit 13 is connected across the terminals of the assembly comprising the circuit breaker 12 and the rapid charging circuit 14. Reference numeral 17 designates a device connected in the battery and supplying a voltage reference at its output; the said device is an element which is responsive to the temperature of the storage cells, in such manner that the reference voltage which is supplied is variable with the temperature of the storage cells. The device 17 is connected to a comparator 18, which is also connected across the terminals 15 and 16 of the battery. The comparator 18 is connected to a trigger device 21 which, finally, acts on the circuit breaker 12.
The functioning of the assembly or system according to the invention is as follows: At the commencement of charging, the circuit breaker 12 is closed and the battery is charged by the rapid charging circuit 14. In accordance with the explanation given hereabove with reference to FIGS. 1 and 2, while the rapid charging current remains practically constant, the charging voltage increases in course of time; similarly, the temperature of the cells increases during rapid charging. It follows that the reference voltage delivered by the device 17 varies and, in this case, increases. According to the invention, the device 17 is selected in such manner that the reference voltage which it supplies undergoes variations with temperature which are substantially analogous to the variations shown in FIG. 2 of the charging circuit cut-off voltage as a function of temperature. This is a considerable advantage of the invention in affording a reference voltage which varies with temperature, as indicated. In fact, in a predetermined charging state close to complete charging of the battery, the charging voltage across the terminals 15 and 16 exceeds the reference voltage supplied by 17. The comparator then transmits information to the device 21, which triggers the opening of the circuit breaker 12. The trigger device 21, which will be better understood in the course of the subsequent description, transmits, in reality, a continuous signal to the circuit breaker which, depending on the magnitude of the said signal, will first of all be closed and then will be open. During the charging of a battery, the circuit breaker is opened only once; thus charging is first of all rapid, and is subsequently slow.
FIG. 4 shows the electronic diagram of an assembly or system permitting rapid charging according to the invention. The feed of the charging circuit is effected with the aid of a magnetic leakage transformer 22. The said transformer is connected to a diode-type rectifier circuit 23. The said rectifier is connected across the terminals 15 and 16 of the battery through intermediary of the thyristor 27. The circuit of the thyristor gate or trigger is fed by the auxiliary winding 47 of the transformer 22 and comprises the diode 24 having the function of a half wave rectifier, and a filter constituted by the resistor 25 and the capacitor 26. Reference numeral 29 designates the transistor energizing the trigger; the resistors 38 and 39 are trigger resistors. When the thyristor 27 is blocked, the charging current flows through the resistor 28 being reduced thereby. The resistor 55 is the emitter resistor of the transisitor 29.
The diodes 41, 42, 43 and 44 are mounted in the battery 19 and responsive to its temperature. The resistor 45, connected in series therewith, is an adjusting resistor. The resistors 35 and 37 constitute a voltage divider bridge connected across the terminals 15 and 16 of the battery; the fraction of the said voltage thus obtained is adjustable by means of the potentiometer 36. When the charger 20 is connected across the terminals 15 and 16 of the battery, the diodes 41, 42, 43 and 44 constitute a portion of a circuit fed by the Zener diode 40 and comprising the resistor 34, the Zener diode 40 being connected to the negative terminals by means of the resistor 50. The transistors 32 and 33 are connected as a common transmitter and their circuit comprises, in conventional manner, the resistors 57, 58 and 59. The fraction of the battery voltage supplied by the divider bridge is filtered by the capacitor 60. The said amplifier provided by transistors 32-33 is connected to the control transistor 29 through intermediary of a second differential amplifier grouping comprising the two transistors 30 and 31, connected as a common emitter; the common terminal of the emitter thereof is connected to one of the terminals of the Zener diode 40 through intermediary of the resistor 53; their respective bases are connected to the same point through intermediary of resistors 51 and 52. The collector of 31 is fed by the resistor 56 and the collector of the transistor 30 is connected to the base of the transistor 29 by the resistor 54. The battery 19 comprises furthermore a safety thermostat 46 connected so as to be capable of blocking the thyristor 27 in the event of excessive heating.
The mode of functioning of the circuit shown in FIG. 4 is as follows: during high-rate charging, the thyristor 27 is conductive. During low-rate charging, the thyristor 27 is blocked and charging is effected through the resistor 28. During rapid charging, the thyristor trigger is fed by the auxiliary winding 47 of the transformer 22, to render the thyristor conductive.
During low-rate charging, the feed of the trigger is interrupted by blocking of the transistor 29. The voltage control is effected by the differential amplifier comprised of paired transistors 32 and 33, which compares a fraction of the battery voltage with the reference voltage. The reference voltage is supplied by the diodes 41, 42, 43 and 44 contained in the battery and in thermal contact with the storage cells, and charged with constant current via the resistor 34, from the constant-voltage tapped across the terminals of the Zener diode 40. The variation in the reference voltage as a function of the battery temperature is provided by varying the direct voltage drop of the diodes 41 to 44 enclosed in the battery. For as long as the fraction of the voltage across the terminals of the battery tapped at the sliding contact of 36 is lower than the reference voltage, the transistor 33 is conductive. It provides for polarization of the transistor 30 which polarizes the transistor 29; the thyristor trigger 27 is fed and it is conductive. When the battery voltage attains the value of the cut-off voltage, the voltage taken off at the sliding contact of the potentiometer 36 becomes equal to the reference voltage. The transistor 32 commences to be conductive and the transistor 33 commences to be blocked. At this instant, the transistor 31, polarized by the transistor 32, becomes conductive and produces an increase in the voltage across the terminals of the resistor 35. This cumulative effect provides for clearly-defined passage of the transistor 32 into the conductive state and of the transistor 33 into the blocked state. The transistors 30 and 29 are blocked and the trigger of the thyristor 27 is no longer fed and it becomes blocked. The voltage shift permitting a new rapid-charging flow is such that the latter is able to occur only if alternating supply cut-off of sufficient duration produces an interruption in low-rate charging.
It should be noted that the capacitor 26 associated with the resistor 25 constitutes a filter, in such manner that the trigger of the thyristor 27 is permanently triggered by a continuous signal. Furthermore, the double differential amplifier comprised of pairs of transistors 32, 33 and 30, 31 affords extremely clear blocking of the control transistor 29 and transition from rapid charging to slow charging is itself very clear and definite. It is an advantage of the present invention that it provides a circuit breaker -- the thyrister 27 -- for the rapid-charging circuit which is permanently controlled by a continuous signal. It should, furthermore, be noted that the capacitor 60 filters the battery voltage fraction at the input of the differential amplifier 32, 33 in such manner that the instant at which the battery voltage fraction exceeds the cut-off voltage supplied by the diodes is ascertained with a high degree of sensitivity.
On the other hand, it should also be noted that the voltage across the terminals of the battery is taken off across the terminals 15 and 16 and is then directly measured by means of the differential amplifier, in such manner as to prevent any voltage drop in connections and to guarantee a high degree of sensitivity in the device or system.
Furthermore, the charging circuit according to the invention comprises a safety thermostat 46 which if dangerous temperatures occur operates to short-circuit the trigger of the thyristor 27 and the charger passes over to the low charging rate. The said thermostatic device 40 guarantees protection of the battery against the following defects: an anomaly in the circuit comprising the diodes 41 to 44; a breakdown in the voltmeter control circuit; failure of the battery voltage to increase at the end of charging after storage for a long period of time.
The diodes 41 to 44 comprise a resistor 45 connected in series in such manner as to compensate for the variations in direct voltage of the diodes for different batteries, with a view to achieving the highest possible degree of precision in respect of the reference voltage. It is one of the advantages of the mode of regulation afforded by the adjusting resistor 45 that one end of the same charger may be used for the charging of a plurality of different batteries.
FIGS. 5A and 5B, together illustrate a variant of the charger according to the invention. The problem of the weight of a charger of this kind has already been discussed hereinabove. A charger according to the invention, intended for the charging of a battery of storage cells of relatively reduced power necessitates a transformer of relatively low weight and involves no particular transport problems; on the contrary, however, in order to charge a battery of relatively high power, the employment of a conventional power circuit (transformer and rectifier bridge) provides a weight and bulk which are incompatible with easy mobility of the apparatus. However, a transformer which has been specially designed for utility with the rapid charger according to the invention could weigh 30 to 40% less than a conventional transformer, but even this reduction in mass will nevertheless be inadequate or insufficient for practical purposes.
The embodiment of FIGS. 5A and 5B obviates these drawbacks.
FIG. 5A shows a novel circuit permitting power supply of the rapid charger according to the invention. The circuit shown in FIG. 5A is directly connected to the circuit of FIG. 5B by the connections of lines A, B, C and D of both Figures.
Reverting to FIG. 5A, the power circuit comprises: a monophase rectifier bridge fed directly by the a.c. power mains and comprising the diodes 93, 94, 95 and 96; the thyrister 27', triggering the charging rate change; the inductor 98; a recovery diode 97; and a current regulating shunt 102.
The power circuit is connected via lines B and A across the terminals 15' and 16' of the battery 19' (FIG. 5B) which is to be charged.
The energizing circuit for the thyristor 27' comprises a transformer 92 having a 1:1 ratio and providing for isolation of the control circuit for the thyristor 27.
This control circuit comprises a single-junction transistor 64 functioning with the aid of resistors 80 and 82; the trigger of the thyristor 27' is connected to the transistor 64 via the resistor 81. The capacitor 79 is charged by the transistor 63 associated with the resistors 74, 75, 76, 77, 78 and 83. The transistor 62, associated with the resistors 69, 71 and 72, with the capacitor 70 and the diode 73, is an amplification stage intermediate between the transistor 63 and the differential amplifier composed of the transistors 101 and 61 associated with the resistors 65, 66 and 68, and with the potentiometer 67. The elements of FIG. 5B -- save for the relay 111 bearing reference numerals like those of FIG. 5 but primed -- have been described in the course of the description given with reference to FIG. 4 and operate in like manner. The mode of functioning of the device or system of FIGS. 5A and 5B follows:
The battery 19' is fed during charging by the power circuit comprising the rectifier bridge having diodes 93, 94, 95 and 96 and also the diode 97. The thyrister control circuit is fed with rectified current via the transformer 92 and bridged diodes 88, 89, 90 and 91.
The single-junction transistor 64 energizes the thyristor 27' with the phase angle corresponding to the charging rapidity of the condenser 79. The charging of the condenser 79 is effected via the transistor 63. The resistor 83 permits, in the absence of regulation, compensation of the input voltage value, by varying the angle of excitation of the thyristor 27'.
Regulation of the current is effected with the aid of the differential amplifier constituted by transistors 101 and 61.
The differential amplifier controls the transistor 62 which varies the voltage applied to the charging circuit of the capacitor 79, in such manner as to adjust the thyristor energization angle, so as to maintain the charging current of the battery at a constant value.
The change of charging rate is triggered, as in the case of the circuit shown in FIG. 4, by the transistor 29' which takes off a portion of the dividing current from the current regulating differential amplifier. Under rapid charging conditions, the transistor 29' is conductive. Regulation of rapid charging is effected with the aid of the potentiometer 36', after having previously regulated the charging current to the low rate via the potentiometer 67.
The triggering of the control circuit providing for the change in charging rate was described in the description with reference to FIG. 4.
The present improvements provide a rapid charger for sealed storage cells, of reduced bulk and weight. By way of example, for a 7 ampere-hour battery, the weight of the needed transformer 92 is reduced from approximately 14 kg. to 4 kg. The value of the power consumed in the a.c. mains by the said charger and also the value of the effective current flowing through the circuit do not exceed the corresponding values for a transformer-type charger. Regulation of the charging current is ± 2% at the high rate and ±15% at the low rate.
In order to prevent accidental shock by contact between the operator and an element under voltage, the device or system of FIGS. 5A and 5B is completed by two safety relays, the control windings of which are designated 111 and 112 respectively. For as long as the battery tap 15'a is not connected to the circuit, the charging circuit is isolated from the mains by the gaps at two contacts 113 and 114 of the relay 112. When the battery tap is in position, the contacts are inaccessible. The coil or relay 111 is then fed with continuous voltage off at the terminals of Zener diodes 84 and 85 through intermediary of studs 15 and 15a of the tap, which are then interconnected.
The contact of the relay 111 produces excitation of the relay 112, the particular coil-feed circuit of which has been designed to provide for the excitation and holding of the relay starting from an input voltage of approximately 100 V, and in order to prevent excessive heating when the input voltage is 140 V.
The resistor 115, shunted by the capacitor 116, is connected in the coil circuit when the relay 112 is triggered. The said resistor 115 produces a voltage drop approximately equal to that of the coil of relay 112. The capacitor 116 cancels the voltage drop of the resistor 115 at the instant of excitation of the relay. The resistor 117 limits the discharge current of the capacitor in the rest contact of the relay.
The invention may be industrially applied to a charger for sealed storage cells permitting the obtaining of almost complete charging in an extremely short period of time. The type of charger described hereinabove is advantageously employed for the charging of sealed nickel-cadmium storage cells. With a charger according to the invention, it becomes possible to charge a plurality of batteries, even of different power.
Although the device or system just described would appear to be most advantageously employed for the carrying into practice of the invention, it will be understood that various modifications may be made thereto within the scope of the appended claims without departing from the invention; some of the said elements, for example, could be replaced by other elements capable of fulfilling the same technical functions. There is no intention, therefore, of limitation to the exact disclosure herein presented.
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A system and method for effecting rapid safe charging of sealed storage cells embodying a charger to supplying a rapid high rate charging current to the cells or battery of cells with interruption but once during charging, at an optimum time to prevent cell or battery damage, the timing of this interruption being effected by change in magnitude of a continuous control signal by means incorporated in the cell or battery. This magnitude changes when voltage across the cell terminals increases above a reference voltage that varies with change in battery or cell temperature, the change in said magnitude of the control signal serving to effect interruption of rapid charging. Subsequent to this interruption charging at a slower rate proceeds to complete the charge of the sealed cell or battery of such cells.
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This application is based on an application number 2002-057148 filed in Japan, the content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved card handling device for magnetic cards with one or more magnetic strips as well as integrated circuit bearing smart cards, hereinafter referred to as an integrated circuit card, or IC card, and a card recycling device. The present invention handles IC cards of either contact or non-contact access technologies.
2. Description of Related Art
A card handling device for magnetic cards and integrated circuit bearing cards is disclosed in Japanese Laid Open patent application No. 10-49725 and includes a card slot, magnetic card handling device, an IC card handling device, and a card storing device for both magnetic and IC cards. The guide of the magnetic card handling device pivots about an axis to allow the magnetic card to be drawn by gravity into a recycling unit.
In the prior art, a magnetic card handling device pivots a predetermined angle on the rotating shaft used as a drive in the card transporting device. The prior art discloses a compact structure, including both the card handling device and the card recycling device in one body.
However, this structure is complex making assembly and maintenance difficult because the rotating shaft for the transporting device is shared as the pivot axis of the magnetic handling device. The magnetic card occurs in two varieties denoted JIS-1 type (JIS-X-6302-1) and JIS-2 type (JIS-6302-2). The JIS-1 type has a magnetic strip on the reverse side of the card, while the JIS-2 type has a magnetic strip on the obverse side, or front face, of the card.
The magnetic heads for reading and writing are located facing the magnetic strips and may physically contact the magnetic strips. The magnetic heads are moveable in operation. The magnetic heads are located opposite from each other, grasping the card between the heads, and providing support for the grasped card to keep it from dropping.
If one of the heads moves, the card is released. If the magnetic heads touch each other without an intervening card present, the magnetic heads may be damaged. Some card handling devices are small in size allowing their use, for example, in ticket vending machines.
SUMMARY OF THE INVENTION
The present invention is directed to a card handling and recycling device.
The card handling and recycling device, includes a card receiving unit which can accept a card inserted from a position external to the device and optionally return the card to a position external to the device, a magnetic card reading and writing unit, a movable integrated circuit card reading and writing unit, a card recycling unit, and a card transporting unit for moving the card selectively within the card handling device along a card transporting passageway.
The card receiving unit, magnetic card reading and writing unit, integrated circuit card reading and writing unit, and card recycling unit are aligned along the card transporting passageway. The integrated circuit card handling unit pivots, block the card transporting passageway, and allowing a card traveling along the card transporting passageway to be diverted into a storage area for recycling the card.
The term card herein applies individually to a card with one or more magnetic strips, an IC card, a smart card, or other card which may be written to and read from using either contact or non-contact means. The phrase card handling comprehends card transporting as described herein, and includes reading and writing. Thus, a card handling and recycling device, or more simply card handling device, includes all aspects of the invention as herein described.
BRIEF DESCRIPTION OF THE DRAWINGS
The exact nature of this invention will be readily apparent from consideration of the following detailed description in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of the card handling and recycling device of the embodiment;
FIG. 2 is a perspective view of the card handling and recycling device the embodiment showing the internal configuration of components;
FIG. 3 is a cross-sectional view of the card handling and recycling device of the embodiment;
FIG. 4 is a cross-sectional view of the card handling and recycling device of the embodiment showing the device operated in the recycling mode;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein to specifically provide a card handling and recycling device. The term card herein applies individually to a card with one or more magnetic strips, an IC card, a smart card, or other card or carrier which may be written to and read from using either contact or non-contact means.
Referring to the view of FIG. 1 , the card handling device 1 includes a card receiving unit 10 with a rectangular slot 11 , a magnetic card handling unit 20 , an IC card handling unit 40 , and a card transporting unit 59 . The card handling device 1 has a frame 6 which includes side frame members 2 and 3 , with cross frame members 4 and 5 mounted between side frame members 2 and 3 .
Referring to the view of FIG. 3 , the card receiving unit 10 , the magnetic card handling unit 20 , and the IC card handling unit 40 are suitably aligned along a card transporting passageway 7 .
Referring to the view of FIG. 2 , the magnetic card handling unit 20 is explained. The magnetic card handling device 20 includes a first magnetic head 21 which in this embodiment uses JIS-1 type cards and a second magnetic head 22 which uses JIS-2 type cards. Alternatively, the first magnetic head 21 and second magnetic head 22 maybe of either type, JIS-1 or JIS2, or they may both be the same type. In the case where only one magnetic head is present in an embodiment, the magnetic head may be of either type.
The first magnetic head 21 can read and write a magnetic strip on a magnetic card, and is fixedly carried near the middle of a lower leaf spring 23 . One end of the lower leaf spring 23 is fixed at a bracket (not shown) and the other end can slide on the bracket. The lower leaf spring 23 is located below the transporting passageway 7 and is aligned so that the sliding end of the leaf spring slides along the direction as the passageway to maintain alignment of the magnetic head 21 with a magnetic card in the transporting passageway 7 . The first magnetic head 21 is mounted so that, when a magnetic card is not presently located for reading or writing by at the magnetic head, the sensing portion of the first magnetic head extends upward slightly above the path traversed by the bottom edge of a magnetic card which is located for reading and writing by the first magnetic head.
The second magnetic head 22 can read and write a magnetic strip on a magnetic card, and is fixedly carried near the middle of an upper leaf spring 24 . One end of the upper leaf spring 24 is fixed at a bracket (not shown) and the other end can slide on the bracket. The upper leaf spring 24 is located above the transporting passageway 7 and is aligned so that the sliding end of the leaf spring slides along the direction as the passageway to maintain alignment of the magnetic head 22 with a magnetic card in the transporting passageway 7 . The second magnetic head 22 is mounted so that, when a magnetic card is not presently located for reading or writing by at the magnetic head, the sensing portion of the second magnetic head extends downward slightly below the path traversed by the upper edge of a magnetic card which is located for reading and writing by the second magnetic head.
The first magnetic head 21 and the second magnetic head 22 are located opposite to each other, and slightly displaced along the card transporting passageway 7 so that magnetic head 21 may contact magnetic head 22 without damage. The magnetic card handling unit 20 may contain either or both of magnetic head 21 or magnetic head 22 , as a magnetic card reading and writing unit, so that magnetic cards of all types may be used.
The first transporting unit 25 is located along the card transporting passageway 7 between the card receiving unit 10 and either or both of magnetic head 21 or magnetic head 22 . The first transporting unit 25 includes a first driving roller 26 which is located below the card transporting passageway 7 and a first pressing roller 27 which is located above the transporting passageway 7 . The first driving roller 26 includes a first rotating shaft 28 which is supported near each end oppositely by side frame members 2 and 3 . Upon first rotating shaft 28 are mounted rollers 29 a and 29 b which are fixed near opposite ends of first rotating shaft 28 .
Rollers 29 a and 29 b each comprise a cylindrical body covered by a ring as an outer surface. The cylindrical body is composed of a harder substance like resin or metal, while the ring around the cylindrical body is composed of a softer material such as rubber. Because magnetic cards and IC cards are the same length and width but may have different thicknesses, the rubber on the rings can be changed to accommodate a desired card thickness. First pressing roller 27 provides resilient support so that cards of different thicknesses may be handled.
The first pressing roller 27 includes a shaft 31 which is fixed in a removable supporting box 30 and rollers 32 a and 32 b which are attached and rotate at the end of shaft 31 . The composition of rollers 32 a and 32 b is the same as that of rollers 29 a and 29 b . Roller 32 a is located above roller 29 a , separated from roller 29 a by less than the thickness of the anticipated card so that the card may be suitably grasped between rollers 29 a and 32 a . Similarly, roller 32 b is located above roller 29 b , separated from roller 29 b by less than the thickness of an anticipated card so that the card may be suitably grasped between rollers 29 b and 32 b.
First driving roller 26 and first pressing roller 27 are located oppositely on either side of the card transporting passageway 7 . The first pressing roller 27 has contact with the first driving roller 26 , but the card is not damaged since the rubber ring is easily deformable.
Referring to the view of FIG. 3 , the IC card handling device is explained. The IC card handling device 40 includes a card guiding unit 41 and an IC card reading and writing unit 42 . The IC card reading and writing unit 42 can handle either contact or non-contact IC card types. The card guiding unit 41 comprises a channel-like shape, bounded by a pair of plates 44 and 45 which pivot on-the third rotating shaft 43 and are fixed at the side wall of baseboard 46 . This channel extends along the card transporting passageway 7 . The baseboard 46 is located slightly below the card transporting passageway 7 . The end of rod 48 pivots on pin 47 which is fixed at plate 44 .
The other end of rod 48 can pivot on shaft 51 of crank 50 which is fixed to the output shaft of motor 49 with gears. The moving unit 52 of the card guiding unit 41 includes pin 47 , rod 48 , motor 49 with gear, crank 50 and shaft 51 . The moving unit 52 moves the card handling unit 40 away from alignment with the card transporting passageway 7 . The motivating force for moving unit 52 may be either a linear motor, a pneumatic cylinder, or a solenoid. The IC card handling unit 40 may be moved parallel to the card transporting passageway 7 .
A communication unit 53 , comprising a thin antenna, for non-contact IC cards is fixed at moving plate 54 located above baseboard 46 . The contactor 55 for contact type IC cards, is fixed at moving plate 54 above baseboard 46 . The moving plate 54 can move along the card transporting passageway 7 a predetermined distance toward the side of the magnetic card handling unit 20 . The moving plate 54 is pressed against the side of the magnetic card handling unit 20 by a spring (not shown) and is limited by a stopper (not shown) at the horizontal section of the guiding groove 56 .
Referring to the view of FIG. 3 , projection 57 is fixed at the end of the moving plate 54 which is opposite the magnetic card handling unit 20 and extends orthogonally into the card transporting passageway 7 . The slanting surface 57 b and opposite side 57 a of projection 57 can move across the card transporting passageway 7 .
Referring to the view of FIG. 3 , the second transporting unit 60 is located between the magnetic card handling unit 20 and the IC card handling unit 40 . The second transporting unit 60 includes a second driving roller 61 which is located below the card transporting passageway 7 and a second pressing roller 62 which is located above the card transporting passageway 7 . The second driving roller 61 includes rollers 64 a and 64 b mounted on a second rotating shaft 63 . The rollers 64 a and 64 b are similar to the rollers 29 a and 29 b.
The second rotating shaft 63 is supported on each end by side frame members 2 and 3 allowing rotation of the rotating shaft 63 . Second pressing roller 62 includes rollers 66 a and 66 b which rotate on shaft 65 . Rollers 66 a and 66 b are similar to rollers 32 a and 32 b . Shaft 65 is attached to the removable supporting box 30 . Guiding board 67 is located above and below the card transporting passageway 7 between the card receiving unit 10 and the second transporting unit 60 .
The guiding plate 69 is fixed at the under section of plates 44 and 45 which are located below the card transporting passageway 7 . Bend section 69 a is shaped continuously with guiding plate 69 , a portion of the guiding plate, on the side away from the magnetic card handling unit, is bent downward. Thus, the guiding plate 69 has two sections, the unbended section of guiding plate 69 and the bended section 69 a , which relatively planar surfaces yet which are not aligned in the same plane with each other. Referring to the view of FIG. 4 , when the integrated circuit card handling unit 40 pivots at the third rotating shaft 43 , the plane of the guiding plate 69 crosses the plane of the card transporting passageway 7 at an acute angle described by the initial and final positions of the integrated circuit handling unit 40 while pivoting. The plane of the downward bended section 69 a crosses the plane of the transporting passageway at an angle which is larger than the acute angle at which the plane of the unbended section of the guiding plate 69 crosses the plane of the transporting passageway 7 .
The recycling storage area 39 is located directly below the IC card handling unit 40 . With this arrangement, the length of the card handling device 1 is shorter in length but taller in height. The third transporting unit 70 is located on the IC card handling unit 40 on the side opposite to the magnetic card handling unit 20 .
The structure of the third transporting unit 70 is the same as that of the first transporting unit 25 and the second transporting unit 60 . The third transporting unit 70 includes the third driving roller 71 which is located below the card transporting passageway 7 . The third pressing roller 72 is located directly above the third driving roller and above the card transporting passageway 7 .
The third driving roller 71 is rollers 74 a and 74 b which are fixed at the third rotting shaft 43 . The third rotating shaft 43 is supported near each end by side frame members 2 and 3 . The third pressing roller 72 includes rollers 76 a and 76 b which rotate on shaft 75 . Rollers 76 a and 76 b are made of the same structure as rollers 32 a and 32 b . Shaft 75 is supported by side frame members 2 and 3 .
The distance between the first transporting unit 25 and the second transporting device 60 is such that the card may be supported by both units. The distance between the second transporting unit 60 and the third transporting unit 70 is such that a card may be supported by the second driving roller 61 and second pressing roller 62 , shortly after it passes through the third driving roller 71 and third pressing roller 72 .
When a new card is dispensed to the rectangular card slot 11 , a card dispensing device is mounted at the right side of the third transporting unit 70 . If new cards are not dispensed, the third transporting unit 70 is not included in the card handling device 1 , and only shaft 43 is included. The transporting unit 59 includes the first transporting unit 25 and the second transporting unit 60 . If new cards are dispensed, the transporting unit 59 includes the third transporting unit 70 . The function of the transporting unit 59 is to transport the card to a predetermined direction. The transporting unit 59 may be changed to a different type of moving elements such as a drive belt or other suitable technology.
Referring to the view of FIGS. 1 and 2 , the driving unit 80 of the first transporting unit 25 , the second transporting unit 60 , and the third transporting unit 70 is explained. The timing pulley 83 is fixed on an output shaft 82 of motor 81 with a gear which is located below the card transporting passageway 7 between the second transporting unit 60 and the IC card handling unit 40 .
Timing belt 86 functionally connects timing pulley 83 and timing pulley 84 which is mounted on the second rotating shaft 63 . Timing belt 88 functionally connects timing pulley 84 and timing pulley 87 which is mounted on the second rotating shaft 28 . The timing belt 90 functionally connects timing pulley 83 and timing pulley 89 which is mounted on the third rotating shaft 43 . The first driving roller 26 , the second driving roller 61 , and the third driving roller 71 all rotate synchronously and at the same speed because the timing pulleys 83 , 84 , 87 , and 89 are the same diameter. The driving unit 80 may be changed to another type which rotates the transporting unit 59 at the same speed.
The shutter unit 91 includes plate 92 which is located between the card receiving unit 10 and the first transporting unit 25 and solenoid 93 which moves plate 92 . When the card handling device 1 is active, plate 92 is located outside of the card transporting passageway 7 . After a card is inserted into the card receiving unit 10 , the second sensor 95 , which is located between the first transporting unit 25 and the second transporting unit 60 gets a non-detection situation, plate 92 protrudes into the card transporting passageway 7 .
When the second sensor 95 detects the card again, plate 92 is moved and goes out of the card transporting passageway 7 . The first sensor 96 and second sensor 95 are photo-electrical type in the embodiment, but may be another type with similar functionality.
Next, the operation of the card handling device 1 is explained. First, the handling of a magnetic card is explained. When the card handling device 1 is active, and a card isn't inserted, plate 92 is located outside the card transporting passageway 7 . When a card C is inserted into the rectangular card slot 11 and is moved into the card transporting passageway 7 , it is detected by the first sensor 96 . Upon detection, motor 81 starts and rotates the first transporting unit 25 , the second transporting unit 60 , and the third transporting unit 70 , operated through the driving unit 80 .
Referring to the view of FIG. 3 , when the card handling device 1 is first activated, the first driving roller 26 , the second driving roller 61 , and the third driving roller 71 are rotated in the clockwise direction. Card C is held between the first driving roller 26 and the first pressing roller 27 and thereby transported towards the right when the driving rollers 26 , 61 , and 71 are rotated in the clockwise direction. In this moving process, card C moves between the first magnetic head 21 and the second magnetic head 22 and moves between the second driving roller 61 and the second pressing roller 62 . The first magnetic head 21 reads the data on the JIS-1 type. The second magnetic head 22 reads the data on the JIS-2 type.
Card C is further transported to the right by the second transporting unit 60 . The end of card C arrives in the IC card reading and writing unit 42 . When the first sensor 96 ceases detecting card C, plate 92 is moved into the card transporting passageway 7 by solenoid 93 , and theft is prevented.
The leading end of card C makes contact with the end face 57 a of projection 57 , and moving plate 54 is moved towards the right by card C. When the trailing end of card C passes through the second sensor 95 , the second sensor 95 becomes non-detecting of card C. Motor 81 is stopped based on the end of the detection condition. In this situation, the moving plate 54 moves to the standby position by card C (shown in solid line of FIG. 3 ). The trailing end of card C is held by the second driving roller 61 and the second pressing roller 62 . In this standby situation of card C, a main device handles a predetermined operation, and afterwards it outputs a returning signal.
Motor 81 is reversed based on the returning signal, and the first driving roller 26 , the second driving roller 61 , and the third driving roller 71 rotate in the counter clockwise direction through driving unit 80 . Therefore, card C is transported in the direction of the rectangular card slot 11 by the second transporting unit 60 . On the way, card C moves between the first magnetic head 21 and the second magnetic head 22 and is securely transported by the first transporting unit 25 to the opening of the rectangular card slot 11 in the card receiving unit.
In this process, either or both of the first magnetic head 21 or the second magnetic head 22 may write onto magnetic card C. When the first sensor 96 detects the end of card C, solenoid 93 is excited, and plate 92 is moved to the outside of the card transporting passageway 7 . Also, card C is transported towards the rectangular card slot 11 . Card C is drawn out from card slot 11 , and when the first sensor 96 indicates a non-detection condition, the motor 81 is stopped.
Next, the handling of an integrated circuit card, or IC card, is explained. Integrated circuit card C is inserted into the rectangular card slot 11 and is transported towards the integrated circuit card handling unit along the card transporting passageway 7 by the first transporting unit 25 and the second transporting unit 60 . Therefore, moving plate 54 is kept at the standby position. In this situation, a contactor of the non-contact type integrated circuit card connects with contactor 55 . When the contact type IC card is used, data is recorded using the communication unit 53 .
The integrated circuit card is handled for reading, writing, or both. When the card access is completed, the returning signal is asserted. Motor 81 is then reversed, and the first driving unit 26 , the second driving roller 61 , and the third driving roller 71 all rotate in the counter-clockwise direction through driving unit 80 . Therefore, the card C is transported towards the rectangular card slot 11 by the second transporting unit 60 and the first transporting unit 25 .
Next, recycling of the card C is explained. The process is started after the card C reaches the standby position. When the recycling signal is received by the control unit, the motor 81 is reversed. Card C is then transported towards card slot 11 by second transporting unit 60 and first transporting unit 25 . When first sensor 96 detects the presence of card C, motor 81 is stopped.
Next, motor 49 rotates which causes the card guide 41 to pivot in the clockwise direction on third rotating shaft 43 as shown in FIG. 3 through output shaft 51 together rotation of crank 50 , rod 48 and pin 47 , causing the card guide 41 to rise as shown in FIG. 4 .
The completed upward motion of card guide 41 is then detected by a sensor on plate 45 (not shown), and the sensor outputs a detecting signal. Motor 49 is stopped based on the detecting signal. Therefore, plane of the guiding plate 69 crosses the plane of the card transporting passageway 7 .
Afterwards motor 81 rotates, and card C is transported towards the right as shown in FIG. 3 . Therefore card C is guided by guiding plate 69 and slants to the right and falls down into a recycling section 39 outside of the second transporting device 60 . The transported card is deflected into the recycling section 39 by striking the lower surface of the guiding elate 69 . In this situation, card C is forcibly diverted downwards because the cross angle of the bend section 69 a is larger. The card naturally falls however the transporting section is short. A storing device of cards is located at the recycling storage area 39 (not shown).
The control unit waits a predetermined amount of time based on the time required for card C to fall into the recycling storage area 39 , afterwards motor 81 is stopped. Next, motor 49 rotates, output shaft 51 moves downwards together the rotation of crank 50 . On the other hand, IC card handling device 40 rotates in the counter clockwise direction and becomes level as shown in FIG. 3 and is detected by a sensor (not shown), and motor 49 is stopped.
Next, dispensing a new magnetic card is explained. A new card is transported from a card storing section (not shown) which is located to the side of the third transporting unit 70 adjacent to the integrated card handling unit, on a line opposite from the magnetic card handling unit. The new card is transported towards card slot 11 by the third transporting unit 70 .
As the new card is traveling along the card transporting passageway, the end of the new card pushes the slanting surface 57 B. The moving plate 54 moves along transporting passageway 7 afterwards it is guided by a slanting section of guiding groove 56 and is pushed away from transporting passageway 7 . Thus, the projection 57 is away from transporting passageway 7 , and the new card passes through under projection 56 . Afterwards, the card passes through the second transporting device 60 and the first transporting device 25 to be dispensed from card slot 11 . When first sensor 96 indicates the card is not detected, the motor 81 is stopped, and dispensing of the new card finishes. In the process, the new card is recorded by either of or both the first magnetic head 21 and second magnetic head 22 .
Next, dispensing a new integrated circuit card is explained. A new integrated circuit card is transported towards card slot 11 by the third transporting device 70 , the second transporting device 60 , and the first transporting device 25 . When the first sensor 96 detects the presence of the new integrated circuit card, motor 81 is stopped and then starts again. As has been previously described, the new integrated circuit card pushes the projection 57 and is kept at the standby position and for recording data, afterwards it is dispensed towards card slot 11 .
In an alternative embodiment, the order of the magnetic card handling unit 20 and the integrated circuit handling unit 40 may be interchanged so that the magnetic card handling unit pivots to block the card transport passageway 7 to similarly divert a card from the transport unit into the recycling storage area 39 .
An external control unit receives the signals from the sensors and operates the solenoid, the driving unit 80 , and the motors 49 and 81 .
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A card handling and recycling device, including a card receiving unit which can accept a card inserted into the device and optionally withdraw the card out of the device, a magnetic card reading and writing unit, a movable integrated circuit card reading and writing unit, and a card transporting unit for selectively moving the card within the card handling device along a card transporting passageway. The card receiving unit, magnetic card reading and writing unit, integrated circuit card reading and writing unit, and card transporting unit are aligned along the card transporting passageway. Recycling of cards is accomplished by pivoting the integrated circuit card handling unit so that a transported card will be deflected by a guide plate into a recycling storage area.
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TECHNICAL FIELD
[0001] This invention relates to compositions useful for treating various surfaces including fibers, textiles, paper, hair, and human skin. More particularly, it relates to compositions and methods for treating metal, paper, and textiles which compositions comprise an amphoteric surfactant derived from ethyleneamines, long-chain fatty acids, and acrylic acid. According to one preferred form of the invention the ethyleneamine used as a raw material from which the surfactant is derived is tetraethylenepentamine.
BACKGROUND
[0002] U.S. Pat. No. 5,322,630 provides a method of acidizing a subterranean formation with an acqueous acid solution wherein the acid solution contains corrosion inhibiting amounts of an amine derivative prepared by reacting an unsaturated carboxylic acid with (a) fatty amine or polyamine, or (b) a fatty amido amine or polyamine, or (c) a fatty imidazoline amine or polyamine. The derivative is characterized by the absence of primary amino groups, and preferably contains only tertiary amino groups. Disclosed therein are amphoteric derivatives of a broad range of fatty polyamines, fatty amidoamines, fatty imidazolines and polyamines which are disclosed as being useful as oilfield corrosion inhibitors.
[0003] U.S. Pat. Nos. 6,004,914; 6,200,938; and 6,369,007 teach amphoteric derivatives of aliphatic polyamines, such as diethylenetriamine or triethylenetetramine reacted with long chain fatty acids, esters or triglycerides from various natural or synthetic sources are effective in the softening/texture modification of substrates such as paper, textiles, human skin surfaces and hair tresses, as well as in applications for metal working and lubrication. The polyamines are first reacted with fatty acids, esters or triglycerides derived from various animal, vegetable or synthetic sources ranging in molecular distribution from butyric through erucic acids (e.g. milkfat, soy bean oil, rapeseed oil) to form polyamines or imidazolines; they are then further reacted with unsaturated or halogenated carboxylic acids, carboxylated epoxy compounds or acid anhydrides (e.g. acrylic acid, itaconic acid, chloroacetic acid, maleic anhydrides octadecenyl anhydride) to form the various amphoteric structures.
SUMMARY OF THE INVENTION
[0004] The present invention relates to amphoteric surfactants that are useful in various applications including paper softener, fabric softener, metal working and lubrication. An amphoteric surfactant of the present invention may be made by reacting tetraethylene pentamine (“TEPA”) with 2.5 to 3.0 moles of a fatty acid to form an intermediate amide compound which is then converted to an amphoteric compound by reacting it with 1 to 2 moles of an unsaturated acid species selected from the group consisting of: maleic acid, maleic anhydride, vinyl sulfonic acid, 2-methyl vinyl sulfonic acid, allylsulfonic acid, and acrylic acid. Thus, the present invention concerns compositions of matter useful for treating paper, textiles, and human skin comprising an amphoteric surfactant represented by the formula:
[0005] in which x is any integer selected from the group consisting of 4, 5, and 6; R 1 in each occurrence is independently any alkyl group having between 5 and 25 carbon atoms, whether straight-chain, branched, cyclic, saturated or unsaturated; R 2 in each occurrence is independently selected from the group consisting of: 1) hydrogen; 2) any saturated or unsaturated aliphatic mono- or di-carboxylic acid moiety having one or more carboxyl functional groups and having one or more straight-chain or branched, saturated or un-saturated aliphatic chains containing from 2 to 20 carbon atoms; 3) any saturated or unsaturated aliphatic mono sulfonic acid moiety having one or more —SO 3 H functional groups and having one or more straight-chain or branched, saturated or un-saturated aliphatic chains containing from 2 to 20 carbon atoms; and 4) a radical of the formula:
[0006] in which R 1 has the same meaning as that ascribed to it above.
[0007] According to another embodiment, a composition according to the invention comprises a mixture of at least two components each of which comprise different amphoteric surfactants which are represented by the formula:
[0008] in which R 1 in each occurrence is independently any alkyl group having between 5 and 25 carbon atoms, whether straight-chain, branched, cyclic, saturated or unsaturated; R 2 in each occurrence is independently selected from the group consisting of: 1) hydrogen; 2) any saturated or unsaturated aliphatic mono- or di-carboxylic acid moiety having one or more carboxyl functional groups and having one or more straight-chain or branched, saturated or un-saturated aliphatic chains containing from 2 to 20 carbon atoms; 3) any saturated or unsaturated aliphatic mono sulfonic acid moiety having one or more —SO 3 H functional groups and having one or more straight-chain or branched, saturated or un-saturated aliphatic chains containing from 2 to 20 carbon atoms; and 4) a radical of the formula:
[0009] in which R 1 has the same meaning as that ascribed to it above. According to yet a further embodiment, the above-described mixture comprises:
[0010] a) a first amphoteric surfactant, having a value for x of 4;
[0011] b) a second amphoteric surfactant, having a value for x of 5;
[0012] c) a third amphoteric surfactant, having a value for x of 6,
[0013] with the first amphoteric surfactant being present in any amount between 8.0% and 20.0%; the second amphoteric surfactant being present in any amount between 25.0% and 45.0%; and the third amphoteric surfactant being present in any amount between 35.0% and 60.0%, with all percentages being calculated on a weight basis with respect to all of the amphoteric surfactants present which are defined by the above formula.
DETAILED DESCRIPTION
[0014] An amphoteric surfactant of the present invention is exemplified by the use of TEPA as a raw material, and other amphoteric surfactants according to the invention are readily prepared using the same general procedure but with ethyleneamines such as pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, etc. An amphoteric surfactant according to the invention may be prepared by first reacting TEPA as a starting material with 2.5 to 3 moles fatty acids, to form an intermediate substituted TEPA polyamide. According to one preferred form of the invention, 3 moles of fatty acid are reacted with 1 mole of TEPA to yield the triamide. According to a preferred form of the invention, the polyamide is subsequently reacted with 1 to 2 moles of an unsaturated acid species such as acrylic acid or vinylsulfonic acid to form an amphoteric surfactant. According to one preferred form of the invention, 2 moles of acrylic acid are reacted with one mole of polyamide, which is preferably a triamide. The resulting amphoteric compounds are useful as softeners for tissue paper, fabrics, hair and skin. The resulting amphoteric compounds are also useful as lubricants in metalworking.
[0015] The general reaction scheme for producing an amphoteric surfactant useful in accordance with the present invention is set forth below:
[0016] In reaction (I), one mole of tetraethylenepentamine is caused to be reacted with three moles of the mono-carboxylic acid in which R may be any C 1 through C 25 alkyl group, whether straight-chain, branched, cyclic, saturated or unsaturated. In the case of unsaturated carboxylic acids used as reactant with TEPA, the present invention contemplates the use of both cis- and trans-isomers. According to one preferred form of the invention, the reactant carboxylic acid is oleic acid, although any other carboxylic acid having between about 7 and 25 carbon atoms may be used, or mixtures thereof. The product of the reaction between three moles of the carboxylic acid and TEPA is the triamide shown in formula (II):
[0017] in which the R portion is supplied by the oleic acid.
[0018] This structure represents the predominant product of such reaction according to the invention. In practice, a mixture of positional isomers is formed with the carboxylic acid residue being substituted upon the various possible positions of substitution having an active hydrogen atom at which the acid function of the carboxylic acid is capable of reacting, as is known to those skilled in the art. When fewer than three moles of acid are reacted per mole of TEPA, the resulting product is a mixture of isomers substituted at the first and second; first and third; first and fourth; first and fifth; second and third; and second and fourth positions. The present invention embraces all such positional isomers and mixtures thereof.
[0019] Subsequent reaction of the polyamide shown in formula (II) with an unsaturated acid, such as, but not limited to, acrylic acid according to the formula (III):
[0020] yields an amphoteric surfactant according to the invention, as described generally by formula (0) previously shown, and shown structurally in formula (IV):
[0021] for the case where one mole of acrylic acid is reacted. When an unsaturated sulfonate such as vinylsulfonic acid or allylsulfonic acid is employed, the carboxylic acid group in the above structure is replaced by the group —SO 3 H thus providing an amphoteric surfactant with a sulfonate anionic portion. The structure above represents the predominant product of such reaction according to the invention. In practice, a mixture of positional isomers is formed with the acrylic residue being substituted upon the various possible positions of substitution having an active hydrogen atom at which the unsaturated function of the acrylic acid is capable of reacting, as is known to those skilled in the art. When more than one mole of acrylic or other unsaturated carboxylic or sulfonic acid is reacted, more than one of the possible positions is substituted. The present invention embraces all such positional isomers. Monomers other than acrylic acid may of course be employed in the role just described for acrylic acid, including unsaturated acid species selected from the group consisting of maleic acid, maleic anhydride, vinyl sulfonic acid, 2-methyl vinyl sulfonic acid, and allylsulfonic acid.
[0022] According to one preferred form of the invention, oleic acid is reacted with TEPA at 144° C. for about 6-10 hours and is subsequently reacted with acrylic acid in the presence of propylene glycol or polyethylene glycol at about 105° C. for about 8 hours, or until the reaction is complete. The structures of the reaction product are easily confirmed using NMR and IR spectroscopy.
[0023] The following examples are illustrative of the present invention and should not be construed as being delimitive thereof in any way. In general, any polyalkylene polyamine can be reacted with a fatty acid to yield an amide which is subsequently reacted with acrylic acid to yield an amphoteric surfactants useful in treating hair, skin, paper, textiles and fibers according to the invention.
EXAMPLE 1
Preparation of TEPA+3 Moles Oleic Acid (TEPA Triamide)
[0024] 505.8 grams (1.8 moles) of oleic acid is charged to a 1 L round bottom flask equipped with a mechanical stirrer and nitrogen purge. 113.6 grams (0.60 moles) tetraethylene pentamine (“TEPA”) is slowly added with stirring under nitrogen at such a rate that the temperature is not permitted to exceed 120° C. Following the addition the temperature of the contents of the flask are maintained at 120° C. for 30 minutes, after which time the heat is increased to cause the reactor contents to reach 144° C., at which temperature the reactor contents are maintained for 6 hours further. Condensate is collected in a Dean-Stark trap (theoretical=32.4 ml). The reaction is considered to be complete when the acid number is below 10 meq/gram (acid numbers referred to in this specification are measured by titrating an aqueous sample using aqueous base which is about 0.1 N to a phenolphthalein end point and calculating the acid number using the relation:
meq/gram=(( B )×( N )×56.1)/(weight of sample in grams)
[0025] in which B=the total number of milliliters of base used; and
[0026] N=the Normality of the base used.
[0027] The resulting product is a waxy solid at room temperature. Total yield=93.0% of theoretical, as determined by NMR and IR spectra. The resulting product is a waxy solid at room temperature. Total yield=93.0% of theoretical, as determined by NMR and IR spectra.
EXAMPLE 2
Preparation of TEPA Triamide Amphoteric Surfactant
[0028] To a 3-neck 1 L round bottom flask equipped with a mechanical stirrer, nitrogen purge, and addition funnel is charged 130.6 grams of propylene glycol and 98.3 grams (0.1 moles) of the oleic acid triamide of TEPA prepared from example 1 above. The contents of the flask are heated with stirring to 90° C. until the contents became homogeneous. 7.2 grams (0.1 mole) of acrylic acid are added slowly, and the contents of the flask are maintained at 105° C. for 3 hours. Alternatively, the reaction may be terminated when at least 90% of the acrylic acid has reacted, as determined by quantitative IR spectroscopy.
EXAMPLE 3
Preparation of Ethyleneamine E-100+3 Moles TOFA (E-100 Triamide)
[0029] Ethyleneamine E-100 (Huntsman Corp.) is a mixture of tetraethylenepentamine (10-15% TEPA), pentaethylenehexamine (33-38% PEHA) and hexaethyleneheptamine (45-54% HEHA). 516.4 grams of tall oil fatty acid (“TOFA”) is charged to a 1 L round bottom flask. under nitrogen purge. 162.6 grams of Ethylenamine E-100 is slowly added with stirring under nitrogen, the temperature being kept below 120° C. throughout the addition. Following the addition, the temperature of the contents of the flask is maintained at 120° C. for 30 minutes. Then the temperature is increased to 144° C. and maintained at 144° C. for an additional six hours. The reaction is considered to be complete when the acid number is below 10.
EXAMPLE 4
Preparation of Ethyleneamine E-100 Triamide Amphoteric Surfactant
[0030] To a 3-neck 1 L round bottom flask equipped with a mechanical stirrer, nitrogen purge, and addition funnel is charged 120.6 grams of propylene glycol and 98.3 grams (0.1 moles) of the oleic acid triamide of TEPA prepared from example 3 above. The contents of the flask are heated with stirring to 90° C. until the contents became homogeneous. 6.5 grams (0.090 mole) of acrylic acid are added slowly, and the contents of the flask are maintained at 105° C. for 3 hours. Alternatively, the reaction may be terminated when at least 90% of the acrylic acid has reacted, as determined by quantitative IR spectroscopy.
Softness Tests for Tissue Paper
[0031] One important aspect of tissue paper for use in personal care such as facial tissue and bathroom tissue is the softness of such papers. In order to evaluate the effect of a compound according to the present invention, several test solutions were made up as follows:
[0032] Sample 1: 48% (TEPA+3 moles oleic acid+2 moles acrylic acid) 52% propylene glycol.
[0033] Sample 2: 48% (TEPA+2.5 moles oleic acid+1.5 moles acrylic acid) 52% propylene glycol.
[0034] Sample 3: 48% (TEPA+2 moles oleic acid+2 moles acrylic acid) 52% propylene glycol.
[0035] Sample 4: 48% (TEPA+2 moles oleic acid+1 moles acrylic acid) 52% propylene glycol.
[0036] Sample 5: 48% (TEPA+3 moles oleic acid+1 moles acrylic acid) 52% propylene glycol.
[0037] Sample 6: 70% of sample 1 mixed with 30% of SURFONIC® E-400 MO (“monooleate”).
[0038] Sample 7: 70% of sample 2 mixed with 30% of SURFONIC® E-400 MO.
[0039] Sample 8: 70% of sample 3 mixed with 30% of SURFONIC® E-400 MO.
[0040] Sample 9: 70% of sample 4 mixed with 30% of SURFONIC® E-400 MO.
[0041] Sample 10: 70% of sample 5 mixed with 30% of SURFONIC® E-400 MO.
[0042] Sample 11: pure SUFRONIC® E-400 MO (SURFONIC® products are available from Huntsman Corporation)
[0043] Control 1: 48% (diethylenetetramine “DETA”+2 moles TOFA (tall oil fatty acid)+1 mole acrylic acid)+52% propylene glycol.
[0044] Control 2: 70% of control 1+30% SUFRONIC® E-400 MO.
[0045] In the above samples, the terminology reminiscent of “(TEPA+2 moles oleic acid+2 moles acrylic acid)” means the amphoteric surfactant produced by reacting TEPA with 2 moles of oleic acid, and subsequently reacting the product thereof with 2 moles of acrylic acid. The various compositions descried above in samples 1-5 were prepared by simple mixing of the specified amount of glycol and amphoteric surfactant. Similarly, for examples 6-10 the specified amounts of materials were blended together. SUFRONIC® E-400 MO is an ethoxylated oleic acid surfactant available from Huntsman Company LLC of Houston, Tex.
[0046] Solutions for treating tissue paper were prepared by making up a 1.0% solution of each of the above samples in water. Evaluations of the effect of each solution were made by immersing a swatch of untreated tissue in each of the 1.0% aqueous solutions containing the material in the samples above. The treated tissue swatches were held in the solution for one minute, and withdrawn. The treated tissue swatches were then dried in an oven at 25° C. The tissues so treated were evaluated for their softness to the touch by several members of our research staff and each given a rating based on the scale: 0=poor/harsh texture; 1=fair; 2=good; 3=very good; 4=excellent/very soft texture. The results of the softness testing is tabulated in the table I below:
TABLE I softness feel test results Sample ID Softness DI Water 0 Sample 6 2.4 Sample 7 2.4 Sample 8 1.2 Sample 9 1.8 Sample 10 3.8 Sample 11 1.4 Sample 5 4.0 Control 1 2.5 Control 2 2.4
[0047] Sample 6 and sample 7 are comparable to the prior art; however, sample 10 and sample 5 are superior to the prior art. In the graph below is the surface response curve for the above samples. It can be seen from the contour plot below of the softness test results that the maximum performance occurs with 3 moles of oleic acid and 1 mole of acrylic acid:
[0048] Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations thereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto. Accordingly, the presently disclosed invention is intended to cover all such modifications and alterations, and is limited only by the scope of the claims which follow.
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Provided herein are amphoteric surfactants derived from ethyleneamines, which surfactants are useful in treating paper, fibers, textiles, hair, and human skin, to impart softness-to-the-touch properties thereto.
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[0001] This invention relates to a new apparatus and method for producing a new product useful as a blown in insulation and made of a orientable polymer (preferably heat setable), e.g. PET, and the new product itself.
BACKGROUND OF THE INVENTION
[0002] Insulation products made from polymer fibers are not new as there are several products in the marketplace, however, most of these applications are for clothing apparel and the like. Blown-in insulation of homes and buildings generally use fiberglass or cellulose.
[0003] There are environmental hazards and inefficiencies using these other materials. For example, fiberglass and cellulose will break apart into fine particles when put through conventional blow-in insulation equipment. These fine particles are hazardous to human beings upon breathing large quantities thereof. In addition, both materials, fiberglass and cellulose, are inferior to polymer (specifically PET) fibers for performance in insulation value and other measurable physical characteristics (such as cycling through wet and dry conditions).
[0004] In the present invention polymer fiber is made by way of a preferred process generally called melt blowing. This method is known in the plastics converting industry as a method to form small diameter fibers. U.S. Pat. No. 5,582,905 assigned to the assignee of the present application discloses a method of making continuous fibers, collecting the fibers and making a batt (lofted in the z direction).
[0005] Fiber (and products) made from the melt blowing process have typically been limited by the properties generated from the melt blow process.
OBJECT OF THE INVENTION
[0006] It is an object of the present invention to overcome the environmental disadvantages of the prior art blown in insulation and to provide an environmentally safe stable lofted polymer insulation having an insulation value superior to the prior art.
SUMMARY OF THE PRESENT INVENTION
[0007] Products of the present invention typically are continuous fibers laid out in a thin web sheet (veil) in the X and Y directions with little or no loft (Z direction).
[0008] The new product of this invention disclosed herein is a non-lofted veil made from a fiber that, produced as a non-lofted veil with fibers in the X and Y direction, is processed to improve its properties and then is cut into short segments (l to 30 mm long) compactly bundled for expansion on location. A significant portion of the fibers of these segments extend in the Z direction upon compaction. When the final product is made the fibers are substantially evenly dispersed into the X, Y and Z directions.
[0009] The present invention enhances the quality of the fiber and the end product (mass of fibers). Specifically, high levels of orientation (in fibers, it is generally monoaxial orientation) and crystallinity are the properties desired for fibers used in insulation product such as blown-in attic insulation. Products such as filtration media where the fibers are enclosed within a structure can utilize even smaller fibers.
[0010] Disclosed is a fiber product for blown-in insulation, made by way of several steps including orientation via the hot air followed by quenching to lock in orientation. Additional orientation is added downstream to the fibers and web by way of further heating mechanical actions including crystallization of the oriented fiber. The fiber is oriented 3 (or more) times during the process under different conditions.
[0011] Specifically a controlled web (veil), essentially a 2 direction (X and Y) product, is produced in which the fibers are oriented twice in the X direction and then a fractional component of the oriented X direction is redirected to lay in the Y direction. This is accomplished by use of the hot air flow in the X direction and the turbulent currents created by that flow and presence of a mechanical roller.
[0012] Nodal points (where 2 fibers cross each other and fast with each other at that point) are created in the X and Y vector (X=machine direction, Y=cross machine direction) to create more and stronger Z direction fiber in the blown-in product.
[0013] Following this the cutting and compaction of the web directs a substantial portion of the fibers into the Z direction which is then packaged. Subsequently blowing (expanding) the product randomizes the X, Y and Z direction fibers to create random matrixes. The physical connections to build loft comes about as individual packets are expanded with multiple nodes within each packet. Loft comes about when each packet builds on one another with physical entanglements generated thru the expansion process making the connections between packets.
[0014] The invention provides:
[0015] a) a new product in the form of a blown-in insulated material made from short polymer fibers with respect to which several intermediate steps in the overall process give the final product key performance characteristics; b) the product is made by way of a modified melt blowing system with modifications providing higher levels of orientation and thermal stability to the fibers, small intermediate compressed packets for better handling and final low bulk density with high loft and high insulating value product; and c) new hardware adapted to work the molecules of the fiber to achieve the blown-in insulation product.
[0016] In order to maximize the properties of the fiber and the product (blown-in insulation) the new blown-in product has several steps by which it is formed.
[0017] The process comprises:
[0018] 1) Fiber formation with a 1 st orientation;
[0019] 2) 2 nd orientation of the fiber;
[0020] 3) Redirection of some fibers to the Y direction, nodes created
[0021] 4) Quench to lock in orientation
[0022] 5) Additional crystallization to the fiber
[0023] 6) Coating the fiber
[0024] 7) 3rd orientation of fiber
[0025] 8) Cutting fiber (multiple layers)
[0026] 9) Compacted packets of fiber
[0027] 10) Packaged (compressed) packets
[0028] 11) Re-expanded fiber expands around nodes (and entanglements).
[0029] According to the invention there is provided a method of producing a non-lofted fiber veil of an orientable polymer for the production of insulation for blown-in applications having X, Y and Z vector directions of the fibers comprising: a) melt blowing the polymer to form molten fibers; b) using a high velocity air flow to orient molecules of the fibers along the length of the fibers, the X vector direction; c) placing the fibers on a mechanical roller adjacent the air flow which is spinning at a rate to provide additional orientation of the molecules of the fibers in the X vector direction as the fibers move across the air flow to the roller; d) using air flow turbulence and roller placement to displace some said fibers into the Y vector direction; and e) cooling the roller to solidify the fibers while on the roller to form the non-lofted fiber veil.
[0030] More specifically according to the invention there is also provided a method of producing a non-lofted fiber veil of an orientable polymer for the production of insulation for blown-in applications having X, Y and Z vectors comprising: a) extruding the polymer by melt blowing to form molten fibers; b) directing a high velocity hot air flow around the extruded fibers with both the air flow and the length of the fibers having the same direction, the X vector direction, to carry the fibers in said direction and to orient the molecules of the fibers along the X vector direction of the fibers; c) locating a mechanical roller adjacent to the fibers being carried in said direction; d) placing the fibers on the roller which is spinning in a direction to carry the fibers away from the air flow; e) choosing a rate of rotation of the roller whereby force generated by the air flow pushing in said direction and the fibers moving across the air flow to the roller yields additional orientation of the molecules of the fibers in the X vector direction; f) placing the roller so that the placement of the roller and turbulence created by the air flow causes a percentage of the fibers to be displaced into a transverse direction, the Y vector; and g) cooling the roller to quench the fibers, after orientation of the molecules thereof subsequent to removal of the fibers from the air flow as they pass over the roller to prevent loss of orientation of the molecules, to form the non-lofted fiber veil.
[0031] Also a feature of the invention is the product of the methods of the previous two paragraphs.
[0032] Also according to the invention there is provided an apparatus for producing a non-lofted fiber veil of an orientable polymer for the production of insulation for blown-in applications having X, Y and Z vector directions of the fibers comprising:
[0033] a) a melt blowing station for blowing the polymer to form molten fibers encompassed by using a high velocity air flow to orient molecules of the fibers along the length of the fibers, the X vector direction; b) a mechanical roller adjacent the air flow arranged to spin at a rate to provide additional orientation of the molecules of the fibers in the X vector direction as the fibers leave the air flow to reach to the roller; and together with air flow turbulence and placement of the roller, to displace some said fibers into the Y vector direction; and c) cooling means associated with the roller to solidify the fibers while on the roller to form the non-lofted fiber veil.
[0034] The invention further provides a non-lofted oriented polymer insulation for blown-in applications comprising multiple layers of oriented polymer veils compressed together and cut to form R-Buds of multiple layers of polymer fibers entangled and connected by nodes expandable upon installation to provide a blown-in insulation.
[0035] Also the invention provides an R-Bud for use in forming a matrix of insulation for blown-in applications of an orientable polymer comprising multiple superimposed layers of non-lofted veils, formed by fibers of said polymer disposed in both of X and Y vectors of X, Y and Z vectors, the veils being interconnected by fibers extending along the Z vector.
[0036] The invention also includes a blown-in insulation comprising a plurality of R-Buds according to the preceding paragraph each expanded to produce the insulation as a matrix of expanded R-Buds.
[0037] The invention further provides a method of producing a blown-in insulation from an orientable polymer comprising: a) producing a plurality of non-lofted veils each having a plurality of fibers of the polymer extending and interconnected in X and Y vectors of X, Y and Z vectors; b) superimposing the-veils and compressing these together to produce interconnection of the layers along the Z vector; c) cutting the interconnected layers into a plurality of R-Buds; and d) expanding the R-Buds, at the time of installation of the insulation, to form blown in insulation comprising a large plurality of the R-Buds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention will now be described, by way of example, with reference to the accompanying drawings in which:
[0039] [0039]FIG. 1 is a diagrammatic schematic of apparatus according to the invention also illustrating the steps of the method according to the invention;
[0040] FIGS. 2 is a sketch showing the veil in the X and Y direction with node points 38 and 40 which continue to remain intact after cutting and compaction as shown in FIGS. 3-10; and
[0041] [0041]FIGS. 3-10 are diagrammatic sketches, micro-photographs and a drawing showing a combination of features all illustrating features of the blown and expanded R-Buds providing for their stable entanglement to provide a lofted insulation.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0042] The apparatus illustrated in FIG. 1 comprises a melt blowing die apparatus 2 for melt blowing molten synthetic fibers entrained in a curtain 4 of air 6 emitted vertically at high speed parallel to the spun fibers at a temperature of about 600° F. ±100° F. The fibers extend primarily in an x direction and may comprise a polyester (i.e. PET) issuing from the nozzles of the apparatus 2 with a diameter of typically about 0.2 to 0.5 mm. These fibers are attenuated, oriented and fibrillated by the curtain of hot air to a statistical mean of about 5 to 15 microns (NOTE 1000 microns=1 mm) while at the same time molecular orientation takes place as the hot air quickly cools to an orientation temperature of about 200° F.
[0043] One of the major limitations to melt blowing in the prior art is that the hot air remains in contact with the fiber. The hot air keeps the fiber above Tg (glass transition temperature) which relaxes the molecules within the fiber thus reducing the orientation of the fiber. Better orientation can be achieved if the fiber after orientation is quenched. This locks in the orientation of the molecules otherwise orientation is lost through relaxation.
[0044] In view of this the fibers are removed from the air stream forming a loop 8 extending to a cold roller 10 rotating in the direction of arrow 12 . The loop 8 provides a second orientation of the fibers which are then quenched on the roller 10 to lock in the orientation. At this stage the fibers form a substantially single layer web- or veil 14 with the majority of fibers in the x direction and some fibers extending in the Y direction of the veil comprising 10-20% of the fibers and with virtually no fibers extending in the Z direction (e.g. out of the plane of the veil).
[0045] It should be noted that there are two types of crystallinity; that induced by mechanical stretching and that formed by thermal energy. It is desirable to form high levels of mechanical crystallinity (orientation) first, and maintain these orientation levels (so as not to lose them through thermal relaxation) and then induce thermal crystals. Standard melt blowing processes give too low a level of orientation and gives thermal crystallization at the wrong time and in a poor manner.
[0046] For insulation products, a higher level of orientation is desired. This orientation will improve physical strength and toughness of the fiber as well as enhancing thermal stability of the fiber. The higher the orientation one can impart to the fiber the thinner the fiber diameter can be made so that the fiber and the mass of fibers will not collapse under its own weight. In turn, building a matrix of fine fibers allows a better insulating product as the matrix impedes the flow of air thus providing greater insulating value.
[0047] A characteristic of PET (and some other crystalline resins) is that it can be oriented which increases the crystallinity level via mechanical action but with PET one can also add crystallinity by way of adding thermal energy that allows crystals to grow. The term heat setting is used in the PET industry to describe crystalline growth through the addition of thermal energy. If the molecules are allowed to relax during heat setting then orientation will be lowered. With standard melt blowing, a good portion of the orientation is lost due to the thermal temperatures of the hot air used to draw the fiber, as the fiber is not restrained. In addition, exposure of the fiber to the hot air yields thermal crystallization. Thermal crystallization without good orientation yields a fiber that is brittle. In addition, the thermal relaxation of orientation causes the fiber diameter to increase as the ‘memory’ of the fiber tries to bring the fiber to its original (larger) fiber diameter. The increased thickness of the fiber is ineffective for insulation and filter products as it changes the bulk density of the final product.
[0048] Thus one or more veils 14 is then passed through a heat setting station 16 in which the veil 14 is restrained in both the X and Y directions to prevent shrinkage while being heated to crystallize the fibers using hot air represented by arrows 18 . Other heating sources could be used i.e. infra red, radio frequency, etc. The restraint is shown diagrammatically at 20 and may comprise webs, plates, veil edge gripping devices, veil gripping porous conveyers etc.
[0049] Following heat setting additional veils 14 are added in overlapping manner to be fed together to a coating station 22 which may comprise coating rollers between which the multiple veils pass to be coated by a lubricant (i.e. a short chain polymer). The multiple veils leave the coating station still extending primarily only in the X and Y directions.
[0050] After coating the multiple veils are passed through a tow forming station 24 to a tow cutting station 26 . The amount of coating can be used to control density in the final blown product. The tow is formed by pressing the multiple veils together in the Y direction to produce an overlapping fiber tow having X, Y and Z dimensions using control plates, rollers, etc. to produce a tow having substantially identical Y and Z dimensions. The cutting station 26 can operate faster than the supply rate of the veils supplied by the coating station 22 thereby cold drawing and further increasing molecular orientation of the fibers and decreasing their diameters.
[0051] The cutting station comprises a standard cutter unit which is adjusted as to speed and tension to cut the tow into compact R-Buds 28 of a desired tightness or density. The cutting operation also increases the proportion of fibers extending in the Z direction. The R-Buds are each of a basically rectangular packet configuration which are then compactly packaged at a packaging station 30 into bags for distribution to an end user.
[0052] The end user who is to install blown-in insulation may use a standard blown insulation installer 32 to expand the R-Buds 28 and add transport air to produce expanded packets of insulation from the R-Buds 28 which become entangled with one another to produce a stable lofted insulation 34 free of binders and brittle components coated only with a lubricant coating.
[0053] The lofted material is suitable not only for thermal but also sound insulation and is also useful as a fibration material among many other potential environmentally non-hazardness uses.
[0054] The re-expansion results in the actual installed product. The final bulk density can be controlled by the amount of mechanical action, velocity of air, coating material or coating amount. The expansion takes place when the R-Buds are put into a mechanical action machine which via a scouring action and the use of air to blow the product takes the compacted R-Buds and expands them into a product that is a 3 dimensional random matrix comprising fibers in equal proportion in the X, Y and Z directions. The bulk density can range from 0.25 to 2 lbs per cubic foot.
[0055] Typical Densities, in lb/cu.ft, of articles
[0056] Veil 0.8+/−.l
[0057] R-Buds
[0058] 12.5+/−5
[0059] Packaged R-Buds
[0060] 17.5+/−5
[0061] Expanded
[0062] 0.25−0.5
[0063] Standard mean fiber diameters from melt blowing operations range from 10 to 50 microns. In insulation, it is better to have smaller diameters but strong fibers. The range of fiber diameters for insulation products will vary depending on final application specifications but can generally be characterized into 2 groups; 1 to 10 micron average diameter and sub-micron 0.1 to 1 micron average. It has been found that for the blown-in insulation product a preferred statistical mean diameter should be in the 2 to 7 micron range.
[0064] The term density can apply to several areas. The individual fiber has a density that is often measured to calculate the degree of crystallization. The term bulk density is used to describe the density of the mass of fibers. For shipping and other purposes, a high bulk density is preferred so as to save space, freight, etc. When the product is used as an insulating material a low bulk density is preferred so as to be cost efficient. The blown-in insulation product also has a yield factor whereby the fiber diameter is critical to thermal insulation efficiency and cost. A smaller fiber diameter which for the same weight per given volume will yield more fibers thus better insulation than a larger diameter fiber.
[0065] For example a product may have the same fiber density and bulk density but very different yield with different fiber diameters. This yield is important to creating a matrix to trap airflow thus providing insulating value. Example: one fiber with a diameter of 0.015 mm and 10 mm long with a density of 1.35 grams/cc has a total mass of 2.4×10 −6 grams. Using the same fiber density, mass and length and adjusting the diameter to 0.0075 mm (half the original) then 4 fibers can be made instead of the one. Nine (9) fibers can be made from the same mass if the diameter is adjusted to 0.005 mm (5 microns). [Note: 1.000 micron=1 mm)
[0066] Thus it is easily determined that the smaller fibers will give a more complex matrix if the fibers are suitably randomized in the X, Y and Z directions. Please note though, at average fiber diameters of less than 3 microns the fiber strength begins to become too weak to support itself in a stand-alone condition/position.
[0067] Referring now to FIGS. 2-10 various nodes and entanglement of the veil and expanded R-Buds 28 is illustrated with reference to the various mechanisms providing a stable lofted product. The redirected Y vector fiber is important to the final product. Interaction of the Y direction fibers with the X direction fibers is very important so as to create a ‘veil’ (web). This veil is made of X and Y fibers that hang together forming a web. The X and Y fibers hang together by several means. The intersections at which they meet are called nodes. These nodes can be formed by several means; entanglements (including twistings) 38 , friction/hang ups 40 , welding 42 , intermolecular attraction 44 due to polarity of the molecules, etc.
[0068] Entanglements are those fibers that wrap around another. Friction/hang ups are where the two fibers intersect and slide until caught at a node. This would be similar to a branch falling from a tree and getting caught in the limbs of a tree (where the limbs intersect the body or larger limb). Weld points are created when the hot fibers touch one another and then are frozen in place by the cold roller. Intermolecular attraction is present in several forms. When oriented a molecule will have a degree of polarity created. The opposite poles will attract and keep fibers together. Further, the fibers rubbing against one another creates static, which in turn, will keep the fibers bonded together.
[0069] The X direction fibers are more oriented than the Y direction fibers but even the Y vector fibers have a degree of orientation and thus have better strength than non-oriented fibers.
[0070] The micro-photographs of FIGS. 8, 9 and 10 illustrate the complexity of intermixed mechanisms controlling the stability of the lofted product after expansion.
[0071] The preferred insulation material is one that is composed of fibers that are thermally stable and have good strength and stiffness. Fibers that are weak will yield under a force. Fibers that are not thermally stable will collapse (due to gravitational force) or distort (shrinkage) upon exposure to elevated temperatures. Fibers that are brittle will break when exposed to any force. In turn, when the fibers are affected the entire insulation product is impacted thus the produce fails.
[0072] A fiber that has good orientation and has been given thermal stability (such as heat setting) will provide a fiber that will make up a good insulation product.
Thermal Orientation Crystallization Result Low High Brittle fiber Low Low Produce collapses when exposed to higher temps High Low Product shrinks and distorts when exposed to higher temps High High Stable/strong product
[0073] The preferred method of the present invention comprises:
[0074] 1. First orientation of fiber: Fiber formation has remained the same as described in previous patent applications assigned to the assignee of the present application. The fiber is extruded from a die which has a multitude of openings (holes, or the like) on the order of 0.5 mm in diameter. This hot extrudate is pushed out of the die hole and forms a molten fiber. High velocity air (e.g. hot for PET or cold for polypropylene) is directed around the newly formed fiber with both air and fiber directed in the same axis. (For this discussion; vertical direction) This air quickly carries the molten fiber downwardly and begins to orient the fiber;
[0075] 2. Second orientation: Instead of keeping the fiber in the hot air until collected, a mechanical roller is located such that it is adjacent to the stream of fibers. See FIG. 1. The fibers are placed on the roller which is spinning. The downward force of the air orients the fiber. The preferred process is such that the fiber forms somewhat of an ‘J’ shape with a half loop at the bottom of the airflow. This force generated by the air pushing downwardly and the fiber trying to move across the airflow yield to produce more orientation as the fiber has restraints and cannot relax. This can be controlled by the vertical and horizontal position of the rollers.
[0076] 3. Y direction: Due to the placement of the roller and the turbulence created by the flow of air a percentage of individual fibers are displaced into the Y vector. The % and diameters of the Y direction fibers can be managed by the RPM and location of the roller relative to the fiber formation;
[0077] 4. Quench: The rotating roller is cool to cold from internal cooling. This cold temperature quenches the oriented molecules in place. Further, the molecules are removed from the hot air to prevent relaxation (loss of orientation) of the molecules. The roller may be designed, i.e. as a corkscrew. to place the Y vector fibers in tension;
[0078] 5. Added crystallization: Depending on the specifications, the fibers may need additional thermal crystallization once they have been orientated. To add thermal crystallization, the fibers are restrained in both the X and Y directions while heat is applied. After sufficient time has elapsed to achieve desired crystallization the fibers have to be quenched while still restrained;
[0079] 6. Coating: To enhance the cutting, compacting and re-expansion of the fibers, it is sometimes desirable to coat the fibers with a lubricant. This lubricant allows faster cutting and compaction and allows a lower installed density upon re-expansion of the fibers;
[0080] 7. Third orientation: Third orientation of the fibers is performed when the fibers are put into the cutter (tow cutter) that can run at a higher speed than the roller feeding it. The fibers are cold drawn adding additional-orientation to the fiber;
[0081] 8. Cutting: Cutting the fiber is accomplished by use of device called a tow cutter. To get optimum performance, several veils are laid on top of one another and then bunched together to form a unit that is like a narrow non-woven rope. The bunching of the veils creates further complexion to the orientation of the fibers. Further entanglements form additional nodes. These bunched veils are cut into packets on the order of 0.400 inches+/−0.300 inches in height;
[0082] 9. Compacting: The fibers are purposely compacted in the tow cutter. This is accomplished by changing the machine process conditions so that discrete 3 dimensional rectangles with compacted fibers are formed. The compacted fibers are formed into an R-Bud. The dimensions of the R-Bud are approximately 0.125 inch wide and 0.375 inch in depth. These packets (R-Buds) are loosely compacted such that friction or the like mechanical action will cause them to come apart. It should be noted that the R-Buds are formed from the veil so that upon dissecting the R-Buds one finds portions of a mini-veil. The fibers are running in the X, Y and now Z directions relative to the R-Bud. The Z direction fibers are important to note as when the R-Bud is expanded into blown in insulation, the fibers then form a 3 dimensional matrix;
[0083] 10. Packaging: For ease of shipment the R-Buds are packaged into a secondary package and some additional compression is added to increase the bulk density. This will ease the cost of freight and handling; and
[0084] 11. Expanding: Expanding the R-Buds via a machine that will expand the R-Buds around the nodes and entanglements to produce a stable lofted product made up of a matrix of the expanded R-Buds, with superior insulating values due to the random 3D matrix of fibers created around the nodes.
[0085] Reference Numerals
[0086] 2 melt blowing apparatus
[0087] 4 curtain
[0088] 6 air
[0089] 8 loop
[0090] 10 roller
[0091] 12 arrow
[0092] 14 veil
[0093] 16 heat setting station
[0094] 18 heat arrows
[0095] 20 restraint
[0096] 22 coating station
[0097] 24 tow forming station
[0098] 26 cutting station
[0099] 28 R-Buds
[0100] 30 packaging sation
[0101] 32 blow installer
[0102] 34 lofted insulation
[0103] 38 entanglement nodes
[0104] 40 hang up nodes
[0105] 42 welded nodes
[0106] 44 static bond nodes
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A method of producing a non-lofted fiber veil of an orientable polymer for the production of insulation, e.g. thermal, for blown-in applications, having X, Y and Z vector directions of the fibers comprising, melt blowing the polymer to form molten fibers, having molecules oriented along the length of the fibers, the X vector direction, placing the fibers on a roller spinning at a rate to provide additional orientation of the molecules of the fibers, displacing some said fibers into the Y vector direction, and cooling the fibers while on the roller to form the non-lofted fiber veil. Also included is the product of the method, a blown in insulation, intermediate products, an apparatus and a method of producing a product for blown-in installation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an endless intermediate transfer belt to which multiple toner images formed of a single color on multiple image forming members are overlappingly transferred. The toner images form a multi-colored image which is transferred to a transfer material. An image forming apparatus including the intermediate transfer belt, an image forming method using the intermediate transfer belt and a method of manufacturing the intermediate transfer belt are also described.
2. Description of the Background
To obtain multi-colored images by using an image forming apparatus such as a photocopier and a printer, the following processes are typically used:
(1) Forming images of a single color on image bearing members; (2) Sequentially overlappingly transferring each color image to an intermediate transfer belt serving as intermediate transfer medium; and (3) Electrostatically transferring the image on the intermediate transfer belt to a transfer material simultaneously.
The image forming apparatus mentioned above has been improved with regard to the speed of photocopying and the image quality and is now expected to have the same image quality as that of printing machines with regard to multiple-color overlapped images.
Published unexamined Japanese Patent Application No. (hereinafter referred to as JOP) 2002-244391 discloses an image forming apparatus which can prevent registration shift during intermediate transfer by controlling the rotation speed of multiple image bearing members and the surface speed of an image transfer belt to form images with good quality without color shift.
In addition, JOP11-109761 discloses an intermediate transfer belt for use informing electrophotographic images which is flow-cast to form an endless belt by centrifugal-molding single-layer structured materials formed of thermosetting resins having a high temperature resistivity such as polyimides, polyamideimides and electroconductive carbon which is dispersed in the resin.
Further, JOP 2003-145561 discloses a technology by which aromatic polyimides having an inflexible structure are highly drawn to orient molecules.
However, the inventions mentioned above have the following drawbacks.
It is practically impossible to eliminate the difference between the rotation speed of multiple image bearing members and the surface speed of an intermediate transfer belt, even after these speeds are controlled. Registration shifts of color images on an intermediate transfer belt thus tend to occur, especially when the belt has a low elasticity modulus. As a result, good image quality is not obtained.
In recent years, more and more photocopiers and printers include a four-tandem engine system (significantly increasing speed), in which a color image is formed in one pass, instead of a single engine system (printing speed is slow), in which a transfer drum must rotate four times to form one color image.
However, since a four color toner image is formed on an intermediate transfer belt in one pass, there is a color shift in the image finally obtained because of slackening between the right hand side portion and the left hand side portion of the intermediate transfer belt, and flexure of the belt between each transfer drum. These problems are caused by transient decrease in the speed of the intermediate transfer belt due to the contact between the intermediate transfer belt and transfer drums for each color.
In addition, in JOP 2003-145561, the technology disclosed therein is not applied to an intermediate transfer belt using a polyimide resin to which an electroconductive agent such as carbon black is added. When this disclosed technology is applied to such an intermediate transfer belt, since a filler represented by black carbon, etc., is mixed in the polyimide film as an electroconductive agent and imparts semi-conductive properties. Thus charged toner particles can be transferred from a transfer drum to an intermediate transfer belt because of this filler. This is true for the case of transfer to a printing paper.
SUMMARY OF THE INVENTION
The present inventors recognized a need exists for an endless intermediate transfer belt for use in forming electrophotographic images which can prevent slackening of the intermediate transfer belt and a registration shift of color images formed thereon, an image forming apparatus having the intermediate transfer belt, and an image forming method using the intermediate transfer belt.
Accordingly, an object of the present invention is to provide an endless intermediate transfer belt for use in forming electrophotographic color images which can prevent slackening of the intermediate transfer belt and a registration shift of images formed thereon to improve the quality of color images formed by using a tandem engine system. In addition, the present invention has another object of providing an image forming apparatus having the intermediate transfer belt mentioned above and an image forming method using the intermediate transfer belt mentioned above.
Briefly these objects and other objects of the present invention as hereinafter will become more readily apparent and can be attained by an intermediate transfer belt including a drawn component not greater than 98% of which is imidized. The intermediate transfer belt is used in an electrophotographic image forming process in which a toner image of each color formed on plurality of image bearing members is overlappingly transferred to the intermediate transfer belt to form a multi-colored image thereon and then the multi-colored image is transferred to a transfer material.
As another aspect of the present invention, an intermediate transfer belt is provided which is prepared by a process including the steps of transferring a mixture of a solution of a thermosetting resin and a particulate electroconductive material into a centrifugal mold, rotating the centrifugal mold to form a film attached to an inner periphery thereof, thermally imidizing the film to have an imidization ratio not greater than 98%; and drawing the film to entirely harden the film and to form the intermediate transfer belt. The intermediate transfer belt is used in an electrophotographic image forming process in which a toner image of each color formed on plurality of image bearing members is overlappingly transferred to the intermediate transfer belt to form a multi-colored image thereon, which is transferred to a transfer material.
It is preferred that the drawing is performed in the circumferential direction of the film.
It is still further preferred that the drawing is performed in the circumferential direction of the film to a drawing magnification power of 1.01 to 1.10.
It is still further preferred that the film is drawn by a drawing base at a constant drawing speed in the circumferential direction thereof while the film is rotated.
It is still further preferred that the drawing is performed in the axial direction of the film.
It is still further preferred that the drawing is performed in the axial direction of the film to a drawing magnification power of 1.01 to 1.20.
It is still further preferred that the drawing is performed in the circumferential direction and the axial direction of the film.
It is still further preferred that the drawing is performed in the circumferential direction and the axial direction of the film to a drawing magnification power of from 1.01 to 1.15.
It is still further preferred that, while the film is rotated, the film is drawn by a chucking portion of a drawing device in a direction different from the rotation direction of the film.
It is still further preferred that the mixture for forming the endless intermediate transfer belt is a polyamic acid solution.
It is still further preferred that the thermal imidizing is performed at a temperature range of from 25 to 220° C.
It is still further preferred that the drawing is performed in a temperature range of from 25 to 220° C.
It is still further preferred that the intermediate transfer belt has an elasticity modulus of from 7,000 to 15,000 MPa.
It is still further preferred that the intermediate transfer belt has a surface resistivity ρs of from 1.0×10 10 to 1.0×10 13 Ω.
It is still further preferred that the intermediate transfer belt has a volume resistivity ρv of from 1.0×10 5 to 1.0×10 11 Ωcm.
As another aspect of the present invention, an image forming apparatus is provided which includes the following: an image bearing member configured to bear a latent electrostatic image; a charging device configured to charge a surface of the image bearing member; a developing device configured to develop the latent electrostatic image with a toner; a cleaning device configured to remove residual toner on the image bearing member; an intermediate transfer belt configured to transfer the toner image on the image bearing member to form an image thereon and to transfer the toner image onto a recording material, the intermediate transfer belt, a fixing device configured to fix the toner image on the recording material. The intermediate transfer belt is prepared by the following: transferring a mixture of a solution of a thermosetting resin and a particulate electroconductive material into a centrifugal mold; rotating the centrifugal mold to form a film attached to an inner periphery thereof; thermally imidizing the film to have an imidization ratio not greater than 98%; and drawing the film to entirely harden the film and to form the intermediate transfer belt.
As another aspect of the present invention, an image forming method is provided which includes the following steps; irradiating an image bearing member with a laser beam to form a latent electrostatic image on the image bearing member; developing the latent electrostatic image with a toner; removing residual toner on the image bearing member; first transferring the toner image to an intermediate transfer belt; second transferring the toner image on the intermediate transfer belt to a recording material; and fixing the toner image on the intermediate transfer belt upon application of heat and pressure. The intermediate transfer belt is prepared by the following process: transferring a mixture of a solution of a thermosetting resin and a particulate electroconductive material into a centrifugal mold; rotating the centrifugal mold to form a film attached to an inner periphery thereof; thermally imidizing the film to have an imidization ratio not greater than 98%; and drawing the film to entirely harden the film and to form the intermediate transfer belt.
As another aspect of the present invention, a method of manufacturing an intermediate transfer belt is provided which includes the following steps: transferring a mixture of a solution of a thermosetting resin and a particulate electroconductive material into a centrifugal mold; rotating the centrifugal mold to form a film attached to an inner periphery thereof; thermally imidizing the film to have an imidization ratio not greater than 98%; and drawing the film to entirely harden the film and to form the intermediate transfer belt. The intermediate transfer belt is used in an electrophotographic image forming process in which a toner image of each color formed on plurality of image bearing members is overlappingly transferred to the intermediate transfer belt to form a multi-colored image thereon, which is transferred to a transfer material.
These and other objects, features and advantages of the present invention will become apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the detailed description when considered in connection with the accompanying drawings in which like reference characters designate like corresponding parts throughout and wherein:
FIG. 1 is a schematic perspective diagram illustrating an example of a method of drawing the endless intermediate transfer belt of the present invention for use in electrophotography in its circumferential direction;
FIG. 2 is a perspective diagram illustrating an example of the drawing device which draws the intermediate transfer belt of the present invention having an endless form for use in electrophotography in its circumferential direction;
FIG. 3 is a schematic perspective diagram illustrating an example of a method of drawing the endless intermediate transfer belt of the present invention for use in electrophotography in its axial direction;
FIG. 4 is a perspective diagram illustrating an example of the drawing device which draws the endless intermediate transfer belt of the present invention for use in electrophotography in its axial direction;
FIGS. 5A to 5F are diagrams illustrating a preparation method of the endless intermediate transfer belt of the present invention for use in electrophotography;
FIG. 6A is a plan view illustrating an electrode for measuring;
FIG. 6B is a longitudinal section illustrating a surrounding of an electrode portion;
FIG. 7 is a schematic lateral view illustrating an example of the image forming apparatus using the endless intermediate transfer belt of the present invention for use in electrophotography; and
FIG. 8 is a diagram illustrating an example of an image printed by the image forming apparatus using the endless intermediate transfer belt of the present invention for use in electrophotography.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below in detail with reference to several embodiments and accompanying drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.
Polymers for use in an intermediate transfer belt for use in electrophotography process performed by a color photocopier are required to have good flame resistance, strength and electric stability. Polyimide resins are excellent materials in terms of strength, thermal resistance and friction chargeability. In embodiments of the present invention, an endless intermediate transfer belt for use in electrophotography may be manufactured using polyimide resins.
Polyimide resins are synthesized from its precursor, i.e., polyamide acids. Polyamide acids have a characteristic in that a polyamide acid change to a polyimide upon application of heat or by a catalyst through imide ring closure and is dissolved in a particular solvent.
In the present invention, various kinds of electroconductive particulate materials or particulate materials having a low electric resistance are used as materials to control the resistance of the intermediate transfer belt. For example, metal powder and metal suboxide powder of tin oxide and indium oxide, and preferably carbon black powder can be used. Also these can be used in combination and nonvolatile liquid having a low electric resistance can be also mixed therewith. In one embodiment, carbon is dispersed in a polyamide acid solution (hereinafter referred to as mixed polyamic acid solution).
Carbon can be typified into acetylene black, oil furnace black, thermal black, channel black, etc. Acetylene black is obtained by thermal decomposition in a furnace where acetylene has been preliminary heated. Oil furnace black can be prepared by blowing oil into a furnace to perform incomplete combustion by controlling the amount of air, and subsequent to cooling down, capturing the carbon with a cyclone, etc. Thermal black can be obtained by alternately heat reserving and heat decomposing natural gas in a regenerative heater in a temperature range of from 200 to 1,700° C. Channel black can be obtained by blowing natural gas flame onto a long strip iron plate and attaching carbon thereto. Materials having a specific gravity close to that of polyamic acid and not much different from that of a resin may be used as electroconductive materials.
There is no specific limitation to the selection of carbons for use in the endless intermediate transfer belt for use in forming electrophotographic images. However, when an intermediate transfer belt having a high surface resistance is desired, carbon providing a high electroconductivity when added in a small amount, such as acetylene black (manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) and ketchen black EC (manufactured by Lion Corporation), may be avoided.
Carbon may be dispersed by supersonic dispersion methods, ballmill dispersion methods, sandmill dispersion methods, etc. Typically, instead of directly dispersing carbon in a polyamide acid solution, carbon is dispersed in N-methyl pyrrolidone (hereinafter referred to as NMP) and the resultant carbon dispersion solution is mixed with a polyamide acid solution. A carbon solution in which carbon having a particular particle diameter is dispersed is thus prepared.
FIG. 5 illustrates a manufacturing method of an endless intermediate transfer belt of the present invention for use informing electrophotographic images. As illustrated in FIGS. 5A and 5B , a predetermined amount of a polyamide acid solution 31 , which is a mixture of a polyamide acid solution 29 and a carbon dispersion solution 30 , is first poured into a centrifugal mold. The mixture is poured while the centrifugal mold is slowly rotated. When pouring the mixture is complete, the rotation speed of the centrifugal mold is gradually increased to a predetermined rotation speed. The centrifugal mold is rotated at the predetermined speed for a predetermined period of time.
In one embodiment, as illustrated in FIG. 5C , the polyamide acid mixture solution 31 is poured into a cylinder mold 33 serving as a centrifugal mold by way of a pouring tube 32 . The cylinder mold 33 has an inner diameter of 100 mm and a length of 250 mm. The cylinder mold is rotated at 10 rpm while the polyamide acid mixture solution 31 is poured until the mixture is completely poured.
Next, as illustrated in FIG. 5D , when pouring is finished, the rate of rotation of the cylinder mold 33 is increased to 400 rpm. Thereafter, the cylinder mold 33 is gradually heated to 100° C. by a heater having a sheet form 34 . The temperature is kept near 100° C. to volatilize the solvent from a polyamide acid mixture solution layer 31 a , which is applied to the inner circumference of the cylinder mold 33 . In one embodiment, the cylinder mold 33 is not heated by a heater having a sheet form 34 , and can be heated by a heating furnace, etc.
The organic solvent evaporates while the centrifugal mold is rotated so that the polyamide acid is increasingly solidified, resulting in formation of a film having a cylindrical form.
In one embodiment, two-axis roll drawing is performed in the temperature range of from 25 to 220° C. in which polyamide acid solution is changed to polyimide through imide ring closure (i.e. partially imidization). When this two-axis-roll drawing is performed at too high a temperature, solidification occurs along with partial imidization, which is not suitable for drawing. In contrast, when this two-axis-roll drawing is performed at too low a temperature, the obtained film does not sufficiently support itself so that it is impossible to draw the obtained film.
In one embodiment, the drying temperature range for drawing is from 80 to 170° C. When the temperature is too high, the surface which is partially imidized is not uniform. When the temperature is too low, the film to be drawn does not have enough strength to support itself.
Next, the device and the method for use in drawing are concretely described.
After sufficiently volatilizing the solvent from the polyamide acid mixture solution layer 31 a , the belt 31 b finished with primary drying is removed from the cylinder mold 33 . The film finished with the primary drying is a partially imidized film (i.e., in a partially solidified state) and also is in a rubber state in which the solvent composition is still contained in a large amount. The film in this rubber state can be subject to swelling treatment using a solvent if necessary.
Next, drawing in the circumferential direction is performed. The belt 31 b removed from the cylinder mold 33 is set on a drawing device for use in drawing in the circumferential direction. The base of the drawing device is moved in the circumferential direction at a particular drawing speed until the belt is drawn while the belt is rotated.
In one embodiment, the drawing magnification power is from 1.01 to 1.10. When the drawing magnification power is too large, the surface property of the belt deteriorates. When the drawing magnification power is too small, the value of the elasticity modulus is not improved by drawing.
While drawing, the partially imidized belt is rotated at a constant speed by a rotation roller. The drawing device base is moved at a speed as low as possible. The diameter of the rotation roller contained in the drawing device may be as large as or less than the diameter of a roller to which the intermediate transfer belt is installed in an image forming apparatus.
The belt can be drawn to the axial direction. A film which has finished with primary drying and achieved a partially imidized state is set on a device for use in drawing in the axial direction to a drawing magnification of from 1.01 to 1.20 as illustrated in FIG. 4 . In addition a partially imidized film which is finished with the circumferential direction drawing can be also set on a device for use in drawing in the axial direction to a drawing magnification of from 1.01 to 1.15.
The partially imidized belt is drawn in the axial direction by a chucking portion remodeled based on a manually-driven drawing device while the partially imidized belt is rotated at a constant speed by a rotation roller.
The method of drawing the belt is not limited to the method mentioned above. The belt can be drawn by other methods such as a tender method and a tube method. The belt can be drawn in a direction different from the circumferential direction by a tender. In one embodiment, the drawing temperature range for drawing is from 25 to 220° C. This drawing temperature can be arbitrarily set depending on conditions.
In one embodiment, the diameter of the rotation roller contained in the drawing device is as large as or less than the diameter of a roller to which the intermediate transfer belt is installed in an image forming apparatus. It is possible to control the thickness of the belt by controlling the outer diameters of the center portion and the end portion of the roller. Thereby, it is possible to prevent deviation of the thicknesses of the center portion and the end portion after drawing.
The physicality of the film can be improved by the drawing treatment mentioned above. The reason why the mechanical strength of the film is improved is that after sufficiently volatilizing the solvent from the polyamide acid mixture solution layer 3 l a (i.e., after primary drying is finished), the arrangement of polyamic acid molecules is aligned in one direction by drawing, resulting in amelioration of the mechanical strength of the film.
The mechanical strength of a film can be controlled by uniformly aligning the molecular orientation. Namely, the strength of an endless intermediate transfer belt for use in forming electrophotographic images can be controlled by controlling the drawing magnification power and the drawing direction.
After the drawing treatment mentioned above, the polyamide acid belt 31 b is set on an imidization mold 37 as illustrated in FIG. 5E . Next, as illustrated in FIG. 5F , the polyamide acid belt 31 b set on the imidization mold 37 is set in a furnace 38 , the temperature of which is maintained to be 300° C. and heated for 20 minutes to obtain a wholly aromatic polyimide belt. The polyamide acid film which has finished with drawing treatment may be further heated for imide ring closure to further improve its characteristics such as thermal resistance, chemical resistance and mechanical strength. This imide ring closure is performed by heating and the solvent remaining in the polyamide acid film is thoroughly evaporated and removed.
The imide ring closure can be performed by heating the film at the temperature mentioned above for the time mentioned above while still rotating the film after the partial imidization treatment and two-axis roll treatment. Also, the imide ring closure can be performed by removing the polyamic acid film from the centrifugal mold, coating the film on a cylindrical imidization mold prepared separately and entirely heating the film and the mold by way of a heating means such as hot air.
The polyimide film thus obtained is suitably processed to a variety of applications. As in the present invention, when the polyimide film is used as an endless intermediate transfer belt for use in the electrophotographic process performed by, for example, a color photocopier, the film is severed to a required length and a member to prevent twisting of the film is set on both open ends thereof if necessary.
In addition, the range of the surface resistivity of the obtained intermediate transfer belt is from 1.0×10 10 to 1.0×10 13 Ω. When the surface resistivity is too high, electric charges are present only on the surface of the intermediate transfer belt and do not move inside the intermediate transfer belt so that the electric field is weak. When the surface resistivity is too low, the electric charges tend to flow in the lateral direction. The range of the volume resistivity of the obtained intermediate transfer belt is from 1.0×10 5 to 1.0×10 11 Ωcm. When the volume resistivity is too high, electric charges are present only on the surface of the intermediate transfer belt and do not move inside the intermediate transfer belt so that the electric field is weak. When the volume resistivity is too low, the electric charges tend to flow in the lateral direction.
Having generally described embodiments of this invention, further understanding can be obtained by reference to certain specific examples which are provided herein for the purpose of illustration only and are not intended to be limiting.
EXAMPLES
The present invention is further concretely described with reference to examples below. The examples below are with regard to belts formed of a polyimide but belts formed of other resin materials can be also used.
FIG. 8 is a diagram illustrating color shifts of color images. Color shift occurring when two line images are formed is described as an example.
In the case of a two-line image in which four colors are overlapped, unless the distances between the two lines for each color are the same, a color shift occurs in the two-line image.
It is not likely that the distance between the two lines formed on a transfer drum for each color varies since the two lines are written on the transfer device for each color with the same writing device.
When the surface speed of each image forming member 1 a , 1 b , 1 c and 1 d matches the surface speed of an intermediate transfer belt 10 (shown in FIG. 7 ) at the transfer portion (i.e., when writing and transferring are synchronized), the images are transferred and overlapped on the intermediate transfer belt 10 from each image bearing member while the distances illustrated in FIG. 8 are maintained as the same, resulting in no occurrence of color shift (shown in FIG. 8( b )).
However, when the surface speed of each image forming member 1 a , 1 b , 1 c and 1 d does not match the surface speed of an intermediate transfer belt 10 at the transfer portion, the line distances on each image bearing member 1 a , 1 b , 1 c and 1 d vary when the image is transferred onto the intermediate transfer belt 10 . Therefore, a color shift occurs as illustrated in FIG. 8( a ).
Example 1
As illustrated in FIG. 5A , a base material 29 and a solution 30 were prepared. In the base material 29 , a polyamide acid was dissolved in NMP such that the amount of the polyamide acid was 20 weight %. In the solution 30 , ASAHI #60H (N-658) (furnace black manufactured by Asahi Carbon Co., Ltd.) was dispersed in NMP. Several kinds of solution can be mixed in each of the base material 29 and the solution 30 .
Next, as illustrated in FIG. 5B , the base material 29 was mixed with the solution 30 in which ASAHI #60H (N-568) was dispersed (hereinafter this mixture is referred to as a polyamide acid mixture solution 31 ). The composition was that ASAHI #60 (N-258) was 22 phr (solid portion) based on the solution portion of the polyimide.
Next, as illustrated in FIG. 5C , the polyamide acid mixture solution 31 was poured to the cylinder mold 33 contained in a centrifugal mold through a pouring tube 32 . The cylinder mold had an inner diameter of 124 mm and a length of 250 mm. When the polyamide acid mixture solution 31 was poured, the cylinder mold 33 was rotated at 10 rpm and this rotation speed was not changed until the pouring was finished.
When the pouring was finished, the rotation speed of the cylinder mold 33 was increased up to 400 rpm as illustrated in FIG. 5D . Thereafter, while the cylinder mold 33 was gradually heated up to 100° C. by a heater having a sheet form 34 and the temperature was kept near 100° C. to volatilize the solvent of the polyamide acid solution layer 31 a coated on the inner circumference of the cylinder mold 33 .
Next, after sufficiently volatilizing the solvent of the polyamide acid mixture solvent layer 31 a , a polyamide acid belt (i.e., a partially imidized belt) 31 b was removed from the cylinder mold 33 , set on a drawing device of drawing the belt in the circumferential direction indicated by arrow A in FIG. 2 , and heated at 120° C. Thereafter the belt was heated at 220° C.
Then, the base of the drawing device was moved at a constant drawing speed to a predetermined drawing magnification power while the partially-imidized belt was rotated. The predetermined drawing magnification power was 1.05 in this case.
After the polyamide acid belt 31 was drawn in its circumferential direction, the polyamide acid belt 31 was set on a device by which the belt was drawn to its axial direction indicated by arrow B in FIG. 4 . The polyamide acid belt 31 b was drawn to a predetermined drawing magnification power by a chucking portion remodeled based on a manually-driven drawing device while the polyamide acid belt 31 b was rotated by a rotation roller. In this example, the polyamide acid belt 31 b was repetitively drawn until the drawing magnification power reached 1.07.
As illustrated in FIG. 5E , the polyamide acid belt 31 b was set on an imidization mold 37 . The imidization mold 37 was then put into a furnace 38 the temperature of which was maintained at 300° C. (as illustrated in FIG. 5F ), and heated for 20 minutes to obtain an intermediate transfer belt.
The elasticity modulus of the intermediate transfer belt manufactured by the processes mentioned above was measured based on JIS-K7127 using a Shimadzu AGS-50A measurement device. The measuring result was that the elasticity moduli in the circumferential direction and in the axial direction were 8,100 MPa and 8,200 MPa, respectively.
The surface resistivity and volume resistivity of the intermediate transfer belt were measured based on JIS-K6911 using a ring electrode 21 and a pillar electrode 22 , as illustrated in FIG. 6A . Based on JIS-K6911, the surface resistivity and the volume resistivity were calculated by using the following formulae:
ρ v=πd 2 /4 t×R v
ρ s =π( D+d )/( D−d )× R s
In these formulae, ρv represents volume resistivity (MΩcm), ρs represents surface resistivity (MΩ), d represents the outer diameter of the pillar electrode (cm), t represents the thickness of the target to be measured, Rv represents volume resistivity (MΩ), D represents the inner diameter of the ring electrode on the surface, Rs represents the surface resistivity (MΩ), and π represents the ratio of the circumference of a circle to the diameter of the circle.
As illustrated in FIG. 6B , the ring electrode 21 and the pillar 22 were concentrically located on the measuring side of the insulation board 24 . The resistance between the ring electrode 21 and the pillar electrode 22 was defined as Rs. When measuring the resistance, an earth electrode 23 was provided on the side opposite to the side to be measured. The surface resistivity of the intermediate transfer belt has a surface resistivity ρs of 6.02×10 11 Ω when the surface resistivity was measured by this measuring method. The resistance between the pillar electrode and its facing electrode was defined as Rv. The volume resistivity ρv of the intermediate transfer belt was 9.03×10 9 Ωcm when the surface resistivity was measured by this measuring method.
Imidization ratio of the intermediate transfer belt was determined based on the peak intensity ratio measured by a transmission method using FT/IR (ATR) SpectrumGX device (PERKIN ELMER).
(Imidization ratio)=(A1780/A1500)/(Aimd 1780/Aimd 1500)×100 In the relationship mentioned above, A1780 represents the absorption intensity based on 1780 cm −1 imide linkage peak of a sample before heat treatment, A1500 represents the absorption intensity based on 1500 cm −1 benzene ring peak of a sample before heat treatment, Aimd 1780 represents the absorption intensity based on 720 cm −1 imide linkage peak of a heat treatment film before drawing, and Aimd 1500 represents the absorption intensity based on 1500 cm −1 benzene ring peak of a heat treatment film before drawing.
The imidization ratio measured by this method was 90%.
An image forming apparatus illustrated in FIG. 7 include the following: photoreceptor drums ( 1 a , 1 b , 1 c and 1 d ), which are charged substances functioning as image bearing members; chargers ( 2 a , 2 b , 2 c and 2 d ) to charge the photoreceptor drums; an irradiation portion (not shown) to irradiate the charged photoreceptor drums to form images thereon; developing devices ( 3 a , 3 b , 3 c and 3 d ) to develop the irradiated images on the irradiated photoreceptor drums with a toner; an intermediate transfer belt 10 to receive the transfer of the toner images developed by the developing devices; photoreceptor cleaners ( 4 a , 4 b , 4 c and 4 d ) to clean the photoreceptor drums; primary transfer rollers ( 5 a , 5 b , 5 c and 5 d ); an intermediate transfer belt driving roller 6 ; an intermediate transfer belt pressing roller 7 ; an intermediate transfer belt opposing roller 8 ; a transfer roller 9 ; a transfer belt cleaner (not shown) to clean the intermediate transfer belt 10 ; and a fixing device (not shown) to fix the toner images transferred onto a transfer material from the intermediate transfer belt 10 .
The developing devices mentioned above have a developing device 3 a for black color, a developing device 3 b for cyan color, a developing device 3 c for magenta color and a developing device 3 d for yellow color.
When the line images illustrated in FIG. 8 were photocopied by the image forming apparatus mentioned above, since there was no speed difference among the photoreceptor drums, the registration shift of each color image did not occur and clear and good images were obtained.
Example 2
The intermediate transfer belt of Example 2 was obtained in the same manner as in Example 1 except that, after volatilizing the solution from the polyamide acid mixture solution layer 31 a , the polyamide acid belt (i.e., partially imidized belt) 31 b was removed from the cylinder mold 33 and set on a drawing device illustrated in FIG. 2 and the temperature was set to 80° C. Imidization ratio was not greater than 90%.
The obtained intermediate transfer belt showed good self-support property. The elasticity modulus of the intermediate transfer belt was measured. The elasticity modulus in the circumferential direction was 7,100 MPa and the elasticity modulus in the axial direction was 7,500 MPa. The intermediate transfer belt had a surface resistivity ρs of 5.12×10 11 Ω and a volume resistivity ρv of 8.12×10 9 Ωcm.
When the line images illustrated in FIG. 8 were photocopied using the image forming apparatus, since there was no speed difference among the photoreceptor drums, the registration shift of each color toner image did not occur and good, clear images were obtained.
Example 3
The intermediate transfer belt of Example 3 was obtained in the same manner as in Example 1 except that, after sufficiently volatilizing the solution of the polyamide acid mixture solution layer 31 a , the polyamide acid belt (i.e., partially imidized belt) 31 b was removed from the cylinder mold 33 and set on a drawing device illustrated in FIG. 2 and the temperature was set to 60° C. The imidization ratio was not greater than 90%.
Although it took a relatively long time in comparison with Example 2, the obtained intermediate transfer belt showed good self-support characteristics. The elasticity modulus of the intermediate transfer belt was measured. The elasticity modulus in the circumferential direction was 7,000 MPa and the elasticity modulus in the axial direction was 7,200 MPa. The volume resistivity ratio of the belt was measured. The intermediate transfer belt had a surface resistivity ρs of 7.12×10 11 Ω and a volume resistivity ρv of 8.92×10 9 Ωcm.
When the line images illustrated in FIG. 8 were photocopied using the image forming apparatus, since there was no speed difference among the photoreceptor drums, the registration shift of each color image did not occur and clear and good images were obtained.
Example 4
The intermediate transfer belt of Example 4 was obtained in the same manner as in Example 1 except that the drawing in the circumferential direction was not performed. The elasticity modulus of the intermediate transfer belt was measured. The elasticity modulus in the circumferential direction was 7,200 MPa and the elasticity modulus in the axial direction was 7,400 MPa. The intermediate transfer belt had a surface resistivity ρs of 6.12×10 11 Ω and a volume resistivity ρv of 9.12×10 9 Ωcm.
When the line images illustrated in FIG. 8 were photocopied using the image forming apparatus, since there was no speed difference among the photoreceptor drums, the registration shift of each color image did not occur and good, clear images were obtained.
The intermediate transfer belt of Example 5 was obtained in the same manner as in Example 1 except that the drawing in the axial direction was not performed. The elasticity modulus of the intermediate transfer belt was measured. The elasticity modulus in the circumferential direction was 7,500 MPa and the elasticity modulus in the axial direction was 7,300 MPa. The intermediate transfer belt had a surface resistivity ρs of 6.17×10 11 Ω and a volume resistivity ρv of 9.17×10 9 Ωcm.
When the line images illustrated in FIG. 8 were photocopied using the image forming apparatus, since there was no speed difference among the photoreceptor drums, the registration shift of each color image did not occur and good, clear images were obtained.
Comparative Example 1
The sample belt of Comparative Example 1 was obtained in the same manner as in Example 1 except that, after pouring the polyimide acid solution, the film was imidized without drawing the film after drying the film up to 100° C. The elasticity modulus of the intermediate transfer belt was measured. The elasticity modulus in the circumferential direction was 3,500 MPa and the elasticity modulus in the axial direction was 3,200 MPa.
When the line images illustrated in FIG. 8 were photocopied using the image forming apparatus, primary transfer of each color toner image was performed well, but each color toner image did not overlap well with the other toner color images. That is, each color toner image was not properly transferred. Therefore, color shifts occurred in the color image on a transfer paper, resulting in failure to obtain good color images.
Comparative Example 2
The sample belt of Comparative Example 2 was obtained in the same manner as in Example 1 except that, after pouring the polyimide acid solution, the drying temperature was up not to 100° C. but to 180° C. The elasticity modulus of the intermediate transfer belt was measured. The elasticity modulus in the circumferential direction was 2,550 MPa and the elasticity modulus in the axial direction was 2,210 MPa.
When the line images illustrated in FIG. 8 were photocopied using the image forming apparatus, primary transfer of each color toner image was performed well, but each color toner image did not overlap well with the other color toner images. That is, each color toner image was not properly transferred. Therefore, color shifts occurred in the color image on a transfer paper, resulting in failure to obtain good color images.
Comparative Example 3
After pouring the polyamide acid mixture solution, drying was performed not up to 100° C. but at 23° C. The result was that a film was not formed. That is, the strength necessary to be drawn was not obtained, i.e., drawing was not performed.
According to the endless intermediate transfer belt obtained in Examples mentioned above, uniform belts in which carbon is well dispersed can be obtained by using a polyamic acid mixture as the base material. As a result, endless belts having an excellent elasticity modulus can be obtained.
In addition, by drying the polyamide acid belt in the temperature range of from 25°C. to 220° C. to imidize the belt, the strength of the belt is strong enough to have good self-supporting characteristics and an imidized film having a uniform surface can be obtained.
Further, by drawing the polyamide acid belt in the temperature range of from 25° C. to 220° C., the film can be optimally drawn without solidifying during drawing.
Furthermore, by limiting the drawing magnification power of the polyamide acid belt in the circumferential direction to from 1.01 to 1.10, a belt having an excellent elasticity modulus can be obtained. When forming an image by using this belt, registration shift of each color toner image does not occur and thus good, clear images can be obtained.
Also, by limiting the drawing magnification power for the polyamide acid belt in the axial direction to from 1.01 to 1.10, a belt having an excellent elasticity modulus was obtained. When forming an image by using this belt, registration shift of each color toner image did not occur and thus good, clear images were obtained.
In addition, as for Examples mentioned above, since the belt has an elasticity modulus of from 7,000 to 15,000 MPa, an intermediate transfer belt having a high elasticity modulus and an excellent mechanical strength can be obtained. Good images without a registration shift in each toner image can be obtained by such an intermediate transfer belt.
Further, since such a belt has a surface resistivity ρs of from 1.0×10 10 to 1.0×10 13 Ω, a good electrophotographic process, i.e., a good transfer process irrespective of the difference in Q /M of a toner, can be performed and thus a good image can be obtained.
Furthermore, since such a belt has a volume resistivity ρv of from 1.0×10 5 to 1.0×10 11 Ω, a good electrophotographic process, i.e., a good transfer process irrespective of the difference in Q/M of a toner, can be performed and thus a good image can be obtained.
This document claims priority and contains subject matter related to Japanese Patent Applications No. 2004-130354 and 2005-117179, filed on Apr. 26, 2004, and Apr. 14, 2005, respectively, each of which are incorporated herein by reference.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth therein.
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An intermediate transfer belt and an image forming apparatus including the belt may include a drawn component not greater than 98% of which is imidized. The intermediate transfer belt may be used in an electrophotographic image forming process in which a toner image of each color formed on plurality of image bearing members is overlappingly transferred to the intermediate transfer belt to form a multi-colored image thereon. The multi-colored image is transferred to a transfer material.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention herein is directed to a ceiling structure and, more particularly, to an attachment technique for fastening suspension runners to an overlying roof deck system.
2. Description of the Prior Art
There is commercially available on the open market a fluted metal deck which is sold by H. H. Robertson Company, under their trade name "QL-99". This roof deck system contains a plurality of flutes and along both edges of the bottom of each flute there is provided ridges. It is with these ridges that the invention herein is meant to cooperate so as to form a mounting structure for the attachment of a suspended ceiling system or other items to the Robertson roof deck.
U.S. Pat. No. 3,300,912 discloses a ceiling system which uses a metal deck. It is noted that the deck must be provided with peninsular segments 43 which are used as the connecting points for the hanger wires of a suspended ceiling system.
U.S. Pat. No. 3,606,720 discloses a metal roof structure which utilizes a clip to fasten structural elements to the metal decking material. U.S. Pat. No. 3,296,751 is a structure similar to the aforesaid patent wherein a clip structure is mounted on a deck-like structure for the purpose of fastening other structural elements to the deck-like structure.
SUMMARY OF THE INVENTION
The invention herein consists of a strap structure which is used in combination with a Robertson roof deck or similar type deck. This type of deck has a corrugated cross section with a plurality of flutes. The flutes are uniformly spaced and form open regions between the adjacent flutes. At the bottom of each flute there is provided a little ridge in the side of the flute. The sheet metal strap herein is designed to be bowed into the open region between two flutes and the ends of the strap are snapped into two facing ridges on two adjacent flutes. The strap is provided with apertures to which may be fastened hanger wires or hanger brackets to carry different structures such as the suspension runners of a ceiling suspension system.
The invention herein provides for the elimination of other more complicated hanger structures for suspended ceiling members relative a metal roof deck. It also eliminates the need of building-in connection points in the metal roof deck so that tie points will be available to fasten a hanger wire directly to the metal roof deck.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an end view of a metal roof deck with the strap invention therein;
FIG. 2 is a top view of the strap invention herein;
FIG. 3 is a modification of the structure of FIG. 1 wherein a hanger bracket is used instead of a hanger wire in conjunction with the strap invention herein;
FIG. 4 is an end view of the structure of FIG. 3; and
FIG. 5 is a perspective view of the hanger strap used in the embodiment of FIGS. 3 and 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The H. H. Robertson Company manufactures a fluted metal deck which they sell under the trade name "QL-99". This particular fluted floor or roof deck is shown in FIG. 1 as element 2. The fluted roof deck is actually a corrugated metal structure which has a series of flutes 4 with their bottoms 6 extending in one common plane. The flutes are uniformly spaced approximately 12 inches apart and have therebetween gaps 8 about 7 inches wide. Along the bottom edges of the flutes there are provided ridges 10 with the ridges of two adjacent flutes 6 facing each other across the gap 8. The flutes and ridges are provided in the metal deck for the purpose of keying to the roof deck a concrete which is poured upon the upper surface of the Robertson roof deck 2.
The invention herein takes advantage of the existence of the ridges 10 and their position on either side of the flutes 4, and, the fact that two adjacent flutes have the ridges 10 facing each other across the gap 8. As shown in FIG. 1, a sheet metal strap 12 is fastened to the Robertson roof deck. A top view of the strap is shown in FIG. 2. The strap is normally made approximately 11/2 inches wide, approximately 8 inches long and is normally made from No. 20 gauge steel. This strap 12 is provided with two apertures 14. The length of the strap is greater than the spacing between two adjacent ridges 10. The sheet metal strap is bowed into the gap 8 between two adjacent flutes 6 and the ends of the strap are engaged in the ridges 10 as shown in FIG. 1. The strap is thus held in place with a concave configuration which is facing downwardly into the area below the roof deck. In the embodiment of FIG. 1, a conventional hanger wire 16 is passed through the two apertures 14 and the end of the hanger wire is wrapped about the body of the hanger wire to hold the wire in position relative to strap 12. The other end of the hanger wire 16 is fastened to a conventional inverted T-bar ceiling runner structure 18. This is a conventional ceiling suspension member which normally has a plurality of apertures therein. The other end of the hanger wire 16 is passed through one of the apertures of the conventional inverted T-bar runner and wrapped about itself so that the wire will be fastened to the inverted T-bar runner. Generally, the conventional inverted T-bar runner has a vertical web and horizontal flanges on either side of the web. On the horizontal flanges ceiling boards are positioned. In the embodiment of FIG. 1, the horizontal flanges would be elements 20 and they would be positioned on either side of the vertical web 22. Ceiling boards 24 would then rest upon the horizontal flanges 20. A plurality of runner members would be put into position and the horizontal flanges of all the runner members would be put in a common plane so as to form a support gridwork for a ceiling system. The hanger wires are used to adjust the spacing on the conventional inverted T-bar runner from the Robertson roof deck and to permit adjustment of individual runners so that all of the horizontal flanges of all of the runners end up in a common plane.
FIG. 3 is another embodiment of the invention herein utilizing the same sheet metal strap 12. The embodiment of FIG. 3 differs from the embodiment of FIG. 1 in that a different type runner structure and hanger structure is utilized. In the embodiment of FIG. 3, a conventional C runner 26 is utilized. In FIG. 4 there is shown the cross section of the conventional C runner 26 and, as can be seen in that figure, the cross section of the runner is basically that of a square sided C. On the lower flange 28 of the C runner, the ceiling boards would be supported. The upper flange 30 of the C runner is the element which will be engaged by the means which clamps the runner in position relative the roof deck structure.
FIG. 5 is a showing of the hanger structure or clamp means 32 which is utilized to fasten the C runner to the Robertson roof deck. As can be seen in FIg. 5, the hanger 32 is a generally U-shaped wire 34 having two legs 36 with the ends of the wires 38 turned in against the legs 36. The hanger structure has the two legs 36 passed down through the apertures 14 in the sheet metal strap 12 and then the structure turned 90° so that the U portion of the body 34 of the clamp will be resting upon the sheet metal strap as shown in FIG. 3. The legs 36 of the clamp are now in position to engage the flange 30 of the C runner.
As shown in FIG. 3, the flange 30 of the C runner engages the bottom 6 of the Robertson roof deck. The legs 36 of the clamp means can now engage the flange 30 and hold the C member in position up against the Robertson roof deck. The structure of FIG. 3 differs from the structure of FIG. 1 wherein the FIG. 1 runner structure is supported below the Robertson roof deck, whereas the FIG. 3 runner structure is clamped up against the bottom of the flutes of the Robertson roof deck. In both cases, the sheet metal strap 12 is bowed between the ridges 10 of the Robertson roof deck to provide an anchor point for receiving the support wire or hanger structure which is utilized to hold the ceiling runner in position. It is obvious that the C runner of the embodiment of FIG. 3 could be replaced by conventional Z or H runners which are known in the art.
By increasing the thickness of the sheet metal strap 12 to increase its strength, the strap could be used to support other objects, such as water or drain pipes, conduit, ductwork, light fixtures, etc.
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A conventional corrugated deck material is used with many roof structures. A strap structure is provided for engaging the corrugations of the deck material so that a conventional ceiling suspension runner for a suspended ceiling system may be suspended from the strap structure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and apparatus for processing recyclable materials. More particularly, the present invention relates to a system and apparatus for sorting and temporarily storing recyclable materials, in which the apparatus includes an intake header box and a plurality of routing channels connected to the header box. During use, a user deposits one or more recyclable items into the intake header box, and the user then presses a selected button to control routing of the deposited item to a pre-sorted storage area. Even more particularly, the present invention relates to a system and apparatus of the type described in which the routing channels are made from modular units, so that the apparatus can be modified or adapted to meet the needs of different users, or the changing needs of a single user.
2. Description of the Background Art
Recycling of certain materials such as, for example, glass, cans, and plastics, among other materials, is becoming more popular in today's increasingly environmentally-conscious society. Many communities now have facilities and equipment to pick up recyclable materials at curbside.
A number of different sorting and storage systems are known for processing recyclable materials. Examples of some of the known sorting and storage systems, for recycling used materials, include those described in U.S. Pat. No. 5,366,097 (Hazlewood), U.S. Pat. No. 5,425,458 (Gilcreest et al.), U.S. Pat. No. 5,447,017 (Becher et al.), U.S. Pat. No. 6,119,869 (Geiman), U.S. Pat. No. 6,141,945 (Becher), and U.S. Pat. No. 6,443,057 (Gazzoli).
Although the known sorting and storage systems have some utility for their intended purposes, a need still exists in the art for an improved modular sorting and storage system and apparatus for processing recyclable materials in the home or in a small business environment. In particular, there is a need for an improved recyclable material processing system which will overcome difficulties encountered with the known art.
SUMMARY OF THE INVENTION
The present invention provides an improved modular system, method and apparatus for processing recyclable materials. An apparatus according to the invention is usable to sort recyclable materials and to temporarily store recyclable materials in separate storage containers by material type, according to input from a user. In one embodiment, the apparatus includes an intake portion, which extends through an exterior building wall and into an interior room of the building, and a routing and storage portion which is disposed outside of the building.
In a first illustrative embodiment of the present invention, a modular apparatus for receiving and sorting recyclable materials is provided, including a hollow intake header box having an inlet door and defining a temporary holding area therein, and a plurality of routing ducts operatively attached to, and extending away from the intake header box. The routing ducts may use passive gravity feed as a mechanism for moving an item therethrough. The apparatus also includes a distribution mechanism operatively connected to the header box. The distribution mechanism is either disposed inside of the header box, or is situated between the header box and the plurality of routing ducts.
The apparatus for receiving and sorting recyclable materials according to the first illustrative embodiment also includes a plurality of selection buttons, either disposed on or operatively connected to the header box, for allowing a user to selectively indicate a material type corresponding to a recyclable item placed in the header box, and to control operation of the distribution mechanism for routing the item to the proper storage receptacle.
The apparatus according to the present invention may also include a plurality of storage receptacles, with a respective one of the storage receptacles disposed at a lower end of each of the routing ducts. Optionally, the storage receptacles may be made substantially sealable, in order to inhibit entry of insects, rodents, and other animals.
According to one embodiment of the present invention, a reflective mirror is mounted in the header box, in order to allow a user to view a reflected image therein of the sorting and distribution area of the system. The mirror enables the user to determine if there is any blockage or interference inside the system from inside a house without having to go outside of the house.
The apparatus for receiving and sorting recyclable materials according to the first illustrative embodiment is constructed using a plurality of interchangeable modular components, so that the apparatus can be adjustably adapted to different applications, depending on the needs of different users, or on the changing needs of a single user.
Many of the interchangeable modular components are made with a hinge-like structure, including a plate portion having a substantially straight peripheral edge, and a plurality of regularly spaced-apart cylindrical tube sections attached to the peripheral edge of the plate portion. Each of the tube sections has a longitudinal axis which is disposed substantially parallel to the peripheral edge to which it is attached. The spaced-apart cylindrical tube sections are adapted to cooperatively intermesh with the spaced-apart cylindrical tube sections of another adjacent modular component, at which point the adjacent modular sections can be interconnected as described below.
When the tube sections of adjacent modular components are intermeshed and aligned with one another, the adjacent components can be connected in one of two ways. The first way of connecting the intermeshed tube sections is to slidably place a rod inside of the aligned tube sections, and the second, alternate way of connecting the intermeshed tube sections is to place an outer, external tube which has a longitudinal portion thereof removed, so that it has a C-shaped cross-section, over and partially covering a substantial exterior portion of the aligned tube sections.
Selected components of the interchangeable modular components may include substantially rectangular plate portions. Other selected components of the interchangeable modular components may include substantially triangular plate portions, or other polygonal plate portions having flat edges.
Optionally, some or all of the plate portions of the interchangeable modular sections may be formed from a translucent or transparent plastic material.
For a more complete understanding of the present invention, the reader is referred to the following detailed description section, which should be read in conjunction with the accompanying drawings. Throughout the following detailed description and in the drawings, like numbers refer to like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an apparatus for receiving and sorting recyclable materials according to a first illustrative embodiment of the present invention;
FIG. 2 is a rear plan view of the apparatus of FIG. 1 , modified to have an enlarged storage area at a central portion thereof;
FIG. 3 is a side elevational view of the apparatus of FIGS. 1-2 , also showing a wall of a building through which part of the apparatus extends;
FIG. 4A is a top plan view of a rectangular modular unit which is a component of the apparatus of FIGS. 1-3 ;
FIG. 4B is a side plan view of the rectangular modular unit of FIG. 4A ;
FIG. 4C is an enlarged detail view of an edge portion of the rectangular modular unit of FIG. 4B ;
FIG. 5 is a top plan view of a pair of modular units of FIG. 4A placed side by side;
FIG. 6 is a top plan view of the modular units of FIG. 4B , moved into an aligned configuration, and also showing a connecting rod for joining the modular units together;
FIG. 7 is a top plan view of two right triangular modular sections which are also components of the apparatus of FIGS. 1-3 ;
FIG. 8 is a top plan view of an equilateral triangular modular section which is another component of the apparatus of FIGS. 1-3 ;
FIG. 9A is a side plan detail view of an intake header, including an angled mirror, which is another component of the apparatus of FIGS. 1-3 ;
FIG. 9B is a front plan detail view of the intake header box of FIG. 9A ;
FIG. 10 is a rear plan view of an apparatus for receiving and sorting recyclable materials according to a second illustrative embodiment of the present invention;
FIG. 11 is a perspective view of a storage container which is a component part of the apparatus of FIGS. 1-3 , shown with a cover thereof in a closed position;
FIG. 12 is a second perspective view of the storage container of FIG. 11 , with a handle depressed in order to release a latching assembly for the cover;
FIG. 13 is a third perspective view of the storage container of FIGS. 11-12 , with the cover being pivotally lifted away from a main body of the container; and
FIG. 14 is a detail view of the handle and latching mechanism of the storage container of FIGS. 11-13 .
DETAILED DESCRIPTION
It should be understood that only structures considered necessary for clarifying the present invention are described herein. Other conventional structures, and those of ancillary and auxiliary components of the system, are assumed to be known and understood by those skilled in the related art.
The present invention provides an improved modular system, method and apparatus for processing recyclable materials. An apparatus according to the invention is usable to sort and separate recyclable materials according to input from a user, and to temporarily store the sorted recyclable materials in separate storage containers by material type.
Referring now to FIGS. 1-3 of the drawings, a first illustrative embodiment of an apparatus for processing recyclable materials is shown generally at 20 . In the embodiment of FIGS. 1-3 , the apparatus 20 includes an intake portion 22 , part of which is adapted to extend through a building wall W ( FIG. 3 ) and into an interior room of a building, such as a single family home, small business, or similar application. The apparatus 20 also includes a routing and storage portion 24 which is adapted to be disposed outside of the building.
In an alternative application of the apparatus 20 , it could be free standing and not associated with a building or other structure. Due to the modular nature of the components making up the apparatus 20 , it may be made large or small, wide or narrow, short or tall, etc, to conform to the environment in which it is used. In addition, after installation in a setting, it may easily be modified, as needed, to fit changing requirements of a user.
In the embodiment of FIGS. 1-3 , the apparatus 20 is usable for receiving, sorting and temporarily storing recyclable materials, such as glass (sorted by color), plastic of different grades, metal cans, etc. The apparatus 20 includes a hollow intake header box 25 , having an inlet door 27 and defining a temporary holding area therein, and a plurality of routing ducts 26 , 28 , and 30 , operatively attached to, and extending away from the intake header box 25 . Within header box 25 is a mirror 29 pivotally mounted by a hinge 14 to the rear wall 25 b of the header box 25 and adjustably supported by a chain 15 attached to the rear wall 25 b of the header box 25 . The mirror 29 has a reflective surface 29 a such that reflective surface 29 a provides a user with a reflected view of the routing ducts 26 , 28 , and 30 and distribution mechanism 32 , from inside the house upon which the system 20 is mounted, without having to go outside to view the entire system 20 .
The routing ducts 26 , 28 , and 30 may use passive gravity feed as a mechanism for moving an item therethrough. Each of the routing ducts 26 , 28 , 30 may have a door 31 formed in a lower section thereof to provide access to a storage receptacle 44 ( FIG. 3 ) disposed therein, and this door 31 may be provided with a unique handle and latch mechanism 33 , as discussed further below. The storage receptacles 44 are disposed above ground level, as shown in FIG. 3 .
The storage receptacles 44 may be formed in different sizes, if desired, to accommodate expected storage needs for different materials. As an example of this, FIG. 2 illustrates that a central routing duct 28 may be made larger at the bottom end thereof than adjacent routing ducts 26 , 30 if it is anticipated that there will be a need for a larger storage receptacle 44 therein. This is just one example of how the modular nature of the apparatus 20 allows it to be made adaptable to accommodate the needs of different users, or the changing needs of a single user.
The apparatus 20 for receiving and sorting recyclable materials according to the first illustrative embodiment also includes a distribution mechanism 32 operatively connected to the header box 25 . The distribution mechanism 32 may be disposed inside of the header box, or alternatively, the distribution mechanism 32 may be situated between the header box and the plurality of routing ducts. The distribution mechanism 32 may include mechanical and/or electromechanical components, and includes at least one movable routing gate. Optionally, the distribution mechanism 32 may include a first selectively operable routing gate situated proximate a first side wall of the header box as shown in FIG. 2 , and a second selectively operable routing gate situated proximate a second side wall of the header box, as shown in FIG. 10 . In addition, if desired, the distribution mechanism 32 may include an optical scanner for reading a code on a recyclable item, to indicate the type of material in the header box 25 .
As seen best in FIG. 9B , the apparatus 20 for receiving and sorting recyclable materials according to the first illustrative embodiment also includes a plurality of selection buttons such as those shown at 34 - 41 , operatively connected to the header box 25 , for allowing a user to selectively indicate a material type corresponding to a recyclable item 45 placed in the header box, and thereby to control operation of the distribution mechanism 32 for routing the item to the proper storage receptacle 44 . The mirror 29 with reflective surface 29 a provides a user with a reflected view of the routing ducts 26 , 28 and 30 allowing a user to view any obstruction within the routing ducts 26 , 28 and 30 and the distribution mechanism 32 .
The apparatus according to the present invention may also include a plurality of storage receptacles 44 , with a respective one of the storage receptacles disposed at a lower end of each of the routing ducts 26 , 28 , 30 . Optionally, the storage receptacles 44 may be made substantially sealable, in order to exclude insects, rodents, and other animals.
The apparatus 20 for receiving and sorting recyclable materials according to the first illustrative embodiment is constructed using a plurality of interchangeable modular components, so that the apparatus can be adjustably adapted to different applications, depending on the needs of different users, or on the changing needs of a single user. Examples of some illustrative modular components include a square component 46 , as shown in FIGS. 4A-4C , and a plurality of triangular components such as those shown at 48 and 50 in FIGS. 7-8 .
Many of the interchangeable modular components are made with a hinge-like structure, and this structure will now be discussed in relation to the square component of FIGS. 4A-4C and 5 - 6 . The hinge-like structure of each modular component, as illustrated by the square component 46 , includes a plate portion 52 having a substantially straight peripheral edge 54 , and a plurality of regularly spaced-apart cylindrical tube sections 56 attached to the peripheral edge of the plate portion. Each of the tube sections 56 has a longitudinal axis, such as that shown at 58 in FIG. 4A , which is disposed substantially parallel to the peripheral edge 54 to which it is attached.
Referring now to FIGS. 5-6 , it will be seen that the spaced-apart cylindrical tube sections 56 along a straight edge portion of the modular component 46 are adapted to cooperatively intermesh with another plurality of spaced-apart cylindrical tube sections 56 ′ of another adjacent modular component 46 ′, at which point the adjacent modular sections 46 , 46 ′ can be interconnected. This can be done repeatedly to create appropriate three-dimensional structures which, in turn, can be joined together to form the apparatus 20 .
When the tube sections of adjacent modular components 46 , 46 ′ are intermeshed and aligned with one another, the adjacent components can be connected in one of two ways. The first way of connecting the intermeshed tube sections 46 , 46 ′ is to slidably place a rod 60 inside of the aligned tube sections, as shown in FIG. 6 . A second, alternate way of connecting the intermeshed tube sections is to place an outer, external tube 62 ( FIG. 4C ) which has a longitudinal portion thereof removed, so that it has a C-shaped cross-section, over and partially covering a substantial exterior part of the aligned tube sections 56 , 56 ′.
As previously noted, some selected components of the interchangeable modular components may include square or substantially rectangular plate portions. Other selected components of the interchangeable modular components may include substantially triangular plate portions.
Optionally, some or all of the plate portions 52 of the interchangeable modular sections may be formed from a translucent or transparent plastic material. If desired, the tube sections 56 may also be formed of plastic.
Referring now to FIGS. 11-13 , a storage receptacle 44 is shown having a removable cover 64 , where the cover includes a main plate 66 , and a handle and latch mechanism 33 connected to the main plate. The handle and latch mechanism 33 on the cover 64 of the storage receptacle 44 shown in FIGS. 11-13 is substantially similar to the handle and latch mechanism used on the access doors 31 of the apparatus 20 , and shown in FIG. 1 .
The handle and latch mechanism 33 includes a hollow support member 65 , which is provided as a three-sided rectangular box rigidly affixed on top of the main plate 66 of the cover 64 . The support member 65 has a hollow cutout formed in the top thereof to provide clearance for the handle 67 , and is also open on the side thereof facing away from the handle.
The handle 67 is pivotally attached to the support member 65 at a pivot connection 70 , which may be provided as a rivet, or as a nut and bolt connection. The handle 67 is a generally L-shaped member, which includes a handgrip portion 68 extending outwardly away from the support member 65 , and a connecting arm 72 , integrally attached to the handgrip portion 68 and extending inwardly inside of the support member 65 . A spring 74 is provided extending between the handle 67 and a movable plate 69 of the handle and latch mechanism 33 . An innermost end of the connecting arm 72 is, in turn, pivotally attached to a linking member 75 , and this linking member is affixed to the movable plate 69 .
An arcuate locking lip 76 is integrally affixed to an outermost portion of the movable plate 69 , and this locking lip extends around an edge of a plurality of tube sections 56 at an edge of a side panel of the container 44 . The arcuate locking lip 76 is sufficiently rounded that when it is in abutting contact with the tube sections 56 , the cover 64 is temporarily locked in a closed position over the top of the container 44 , as illustrated in FIG. 11 .
However, as illustrated in FIG. 12 , when the handgrip portion 68 of the handle 67 is pressed inwardly, that pushes the linking member 75 outwardly and causes the movable plate 69 and the attached locking lip 76 to also move outwardly, away from the tube sections 56 . This disengages the locking lip 76 from the side wall of the container 44 , and permits the cover 64 to be pivotally lifted away from the main body of the container 44 , thus opening the container.
An advantage of the above-described design for the handle and latch mechanism 33 is that when the gripping section 68 of the handle 67 is used to lift and carry the entire storage container 44 , the upward lifting motion on the handle 67 , coupled with the natural downward pull of gravity on the container, tends to pull the movable plate 69 and attached locking lip 76 inwardly, and to easily keep the cover 64 in locked engagement with the main body of the container 44 .
Referring now to FIG. 10 of the drawings, a second illustrative embodiment of an apparatus for processing recyclable materials is shown generally at 120 . The apparatus 120 according to the second embodiment is substantially similar to the apparatus 20 according to the first embodiment as previously described, except as specifically described as different herein.
In the embodiment of FIG. 10 , the apparatus 120 includes an intake portion 122 , part of which is adapted to extend through a building wall W ( FIG. 3 ) and into an interior room of a building, such as a single family home, small business, or similar application. The apparatus 120 also includes a routing and storage portion 124 which is adapted to be disposed outside of the building.
In the embodiment of FIG. 10 , the apparatus 120 for is usable for receiving, sorting and temporarily storing recyclable materials, such as glass (sorted by color), plastic of different grades, metal cans, etc. The apparatus 120 includes a hollow intake header box 125 , having an inlet door (similar to that shown at 27 in FIG. 9B ) and defining a temporary holding area therein, and a plurality of routing ducts 126 - 130 , operatively attached to, and extending away from the intake header box 125 . The routing ducts 126 - 130 may use passive gravity feed as a mechanism for moving an item therethrough. Each of the routing ducts 126 - 130 may have a door formed in a lower section thereof to provide access to a storage receptacle 44 ( FIG. 3 ) disposed therein.
The apparatus 120 for receiving and sorting recyclable materials according to the second illustrative embodiment also includes a distribution mechanism 132 operatively connected to the header box 125 . The distribution mechanism 132 may be disposed inside of the header box 125 , or alternatively, the distribution mechanism 132 may be situated between the header box and the plurality of routing ducts 126 - 130 . The distribution mechanism 132 may include mechanical and/or electromechanical components, and includes at least one movable routing gate. Optionally, the distribution mechanism 132 may include an optical scanner for reading a code on a recyclable item, to indicate the type of material in the header box 125 .
Although the present invention has been described herein with respect to a number of specific embodiments, the foregoing description is intended to illustrate, rather than to limit the invention. Those skilled in the art will realize that many modifications of the preferred embodiment could be made which would be operable. All such modifications, which are within the scope of the claims, are intended to be within the scope and spirit of the present invention.
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A system and apparatus for processing recyclable materials, including a header box, a plurality of routing channels connected to the header box, and a temporary storage container for each routing channel. During use, a user deposits one or more recyclable items into an intake header box, and the user then presses a selected button, corresponding to the material of the item, to control routing of the deposited item to a pre-sorted storage area. The header box includes a mirror, showing the routing channels, to allow a user to determine if the system is clear or blocked. The routing channels are made from modular units, so that the apparatus can be modified or adapted to meet the needs of different users, or the changing needs of a single user.
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RELATED APPLICATIONS
This application claims the benefit of priority under 35 U.S.C. 119(e) to pending U.S. non-provisional application Ser. No. 12/030,203 itself claiming priority to provisional No. 60/889,525, filed on Feb. 2, 2007, the entire contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to light fixtures, luminaires, lamps, or other light emitting devices used for illumination. The system and methods are particularly applicable to collimated light sources such as incandescent and discharge lamps with parabolic reflectors or solid state lighting sources. The system and methods are also particularly effective with arrays of light sources such as those often used in solid state lighting.
BACKGROUND
The invention relates to improved performance of light fixtures. Light fixtures are also commonly referred to as luminaires and represent a complete lighting unit consisting of a lamp(s) electrical controls (when applicable), together with the parts designed to distribute the light, to position and protect the lamps, and to connect the lamps to the power supply. Additionally, a light fixture converts a light source into an illuminated object that may be viewed directly and should contain optical technology to make this a pleasant experience for humans. Often this requires diffusing or re-directing light in order to reduce the brightness of a light source or create a larger or more uniform light emitting surface.
For most lighting applications, principal functions of a light fixture are to aesthetically modify the appearance of light sources and to control the distribution of emitted light. A number of optical components such as diffusers, lenses, reflectors, and louvers are commonly used for these purposes. Often times, collimation of light is desirable to reduce the beam angle output of a luminaire in order to increase the intensity of projected light. Narrow beam outputs are commonly created by the use of parabolic reflectors that are commonly used with incandescent, fluorescent, and metal halide lamps. Narrow beam angle LED light sources are commonly created through combinations of primary and secondary optics. In many cases, a polymer material is used as an encapsulant of the LED chip and forms a domed lens. Injection molded secondary optics that further collimate the light output of an LED package are also commonly used. Some of these are parabolic type reflectors and others use total internal reflection (TIR) to redirect light and collimate light. Typical collimating optical components creates a desirable increase in intensity within the beam angle but also boost peak brightness of a luminaire and create high contrast background for the eye, creating objectionable glare and impairing vision. Most standard collimating optical elements produce a symmetrical beam angle output. Asymmetrical collimating components exist but require significant technical expertise and time to design. Additionally, collimating components are typically manufactured by injection molding and the time and expense of producing accurate tooling for injection molding is significant. A particular asymmetrical collimating component is limited in use to providing a very specific optical output when coupled to a very specific light source. Therefore, when developing a product line of commercial luminaires it is advantageous for a luminaire manufacturer to utilize pre-existing standard collimating optical components or design as few custom collimating optics as possible.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a pendant light fixture and represents an embodiment of the invention.
FIG. 2 is an angled view of a pendant light fixture and represents an embodiment of the invention.
FIG. 3 is a view of a wall sconce light fixture and represents an embodiment of the invention.
FIG. 4 is a side view drawing of a pendant light fixture configured as an embodiment of the invention.
FIG. 5 is a cross-section side view drawing of the same pendant light fixture embodiment as shown in FIG. 4 .
FIG. 6 is a side view drawing of a bulb-like embodiment feasible for use as a downlight or pendant light fixture.
FIG. 7 is a cross-section side view drawing of an embodiment with the same exterior side view as shown in FIG. 6 .
FIG. 8 is an cross-section side view drawing of an alternative embodiment with the same exterior side view as shown in FIG. 6 .
FIG. 9 is an alternative downlight or pendant embodiment with a patterned light scattering region.
DETAILED DESCRIPTION
The features and other details of particular embodiments of the invention will now be more particularly described. It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The illustrations are not drawn to scale in order to illustrate particular features and properties. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. All parts and percentages are by weight unless otherwise specified.
DEFINITIONS
For convenience, certain terms used in the specification and examples are collected here.
“Diffuse” and “diffusing” as defined herein includes light scattering or diffusion by reflection, refraction or diffraction from particles, surfaces, or layers or regions.
“Diffuser Plate” and “Diffuser Film” and “Diffuser” are referred to herein as optical elements that provide a scattering or diffusion property to one or more light rays. The change in angle of a light ray may be due to refraction, internal forward and backward scattering, or diffraction. As suggested here a diffuser plate (or film) may be thin and may incorporate many layers or regions providing different properties. A diffuser plate may incorporate other features or materials in the volume or on one or more surfaces that impart a desired optical, thermal, mechanical, electrical, or environmental performance.
“Optical throw” as defined herein refers to the linear distance from the light fixture or light source to the region with the largest illuminance in the illumination pattern.
“Optically coupled” is defined herein as condition wherein two regions or layers are coupled such that the intensity of light passing from one region to the other is not substantial reduced by Fresnel interfacial reflection losses due to differences in refractive indices between the regions. “Optical coupling” methods include methods of coupling wherein the two regions coupled together have similar refractive indices or using an optical adhesive with a refractive index substantially near or in-between the regions or layers. Examples of “Optical coupling” include lamination using an index-matched optical adhesive, coating a region or layer onto another region or layer, or hot lamination using applied pressure to join two or more layers or regions that have substantially close refractive indices. Thermal transfer is another method that can be used to optically couple two regions of material.
“Anisotropic ratio” as defined herein refers to the ratio between the FWHM diffusion angle in the machine direction of a diffuser film and the FWHM diffusion angle in the axis perpendicular to the machine direction.
“See through” as defined herein refers to the phenomenon that can be described differently depending on the context. When one refers to scattering or diffusion in a diffractive sense, one can speak of diffraction orders, although for traditional symmetric and asymmetric diffusive mediums the non-zero diffractive orders do not have well-defined angular ranges. However, one can refer to the un-deviated light as the zero order when passing through a diffuser. One may refer to “see through” as the zeroth ordered light that is un-scattered or un-diffracted after passing through a diffusing medium. A perfectly clear film will be referred to as having significant see-through and a hazy film will be referred to as having little or no see-through. See through is also commonly referred to as specular transmission.
“Clarity” is defined as the ratio of the amount of unscattered light to transmitted light expressed as a percentage using a ring sensor at the exit port of a haze meter as defined by ASTM D1003 standard and BYK documentation referring to Transmission, Haze, and Clarity definitions. The relation between the amount of unscattered light (IC-IR) and transmitted light (IC+IR) is expressed in percentage or
Clarity = 100 % · ( IC - IR ) ( IC + IR )
where the light intensity in the inner ring is IC and the intensity of the light in the outer ring sensor is IR. Clarity generally refers to the amount of low-angle scattered light. It is used here as one metric to quantify “see through.” The Clarity measurement effectively describes how well very-fine details can be seen through the optical element. The see-through quality is determined in an angle range smaller than 2.5 degrees and the measurement of clarity depends on the distance between sample and observed object.
“Uniformity” is defined as one minus the standard deviation divided by the arithmetic average of the values. An ideal sample with perfect uniformity will have a uniformity value of 1.
“Illumination Uniformity” is defined as the uniformity of the illuminated area.
“Illuminated area” is defined as the area enclosed by the boundary where the intensity of the illumination falls to 50% of its peak value.
“Hot spot” refers to local fluctuations that have significant luminance differences (contrast) between two neighboring regions.
DETAILED DESCRIPTION
In one embodiment of this invention, a light fixture comprises a light source, a collimating element, an optical cavity and a multi-functional non-imaging optical component (MNOC) comprising an anisotropic light scattering film. In another embodiment of this invention, the MNOC further comprises a surface relief feature which redirects a portion of the incident light.
Backward Scattering
In one embodiment of this invention, a volumetric anisotropic scattering diffuser with scattering properties in the backwards direction is used to further increase the uniformity of the light fixture in a spatial, radial, or linear pattern. In a further embodiment, the backscattering is substantially isotropic to provide improved uniformity along at least two spatial axes and increases the illumination uniformity or preferentially scatter light within one or more planes to provide more even illumination of a wall. In one embodiment, the scattering is anisotropic such that light is scattered backward with a larger FWHM in a plane parallel to the optical axis than within a plane perpendicular to the optical axis. In a particular embodiment, the asymmetry ratio (the ratio of the full-width-half maximums) of the light scattered backward is greater than 2. In a further embodiment, the ratio is greater than 10. In an additional embodiment, the ratio is greater than one selected from the following group consisting of 50, 80, 100. In one embodiment, the scattering is anisotropic such that light is scattered backward with a larger FWHM in a plane perpendicular to the optical axis than within a plane parallel to the optical axis.
In a further embodiment, the diffuse reflectance (specular component excluded) is greater than 5%. In a further embodiment, the diffuse reflectance is greater than one chosen from the group consisting of 10%, 20%, 50%, 75%.
Light Profile Incident on Anisotropic Diffuser
In one embodiment of this invention, the light incident on an anisotropic diffuser is substantially collimated. The light may be collimated by primary optics such as a reflector cup or encapsulant, secondary optics such as the molded plastic lenses or reflective plastic optics, or through the use of photonic crystalline structures on an LED die or through the use of laser diodes or other substantially collimated light sources. In one embodiment, the degree of collimation is 5 degrees FWHM. In a further embodiment, the collimation is one selected from the group consisting of 10 degrees, 20 degrees, 30 degrees, 60 degrees, 100 degrees, or 120 degrees. When the light source is substantially collimated, the light can be directed such that a pre-determined amount of the light does not pass through the anisotropic diffuser and illuminates in a spot-like pattern for applications such as spot-lighting or pendant light fixture, down-lighting, or track-lighting applications.
Surface Features
In one embodiment of this invention, a surface with relief features is disposed near the volumetric anisotropic scattering region. Example surface relief features includes a prismatic film, microlens array, and other surface relief features and it can be optically coupled to the anisotropic diffuser or embossed directly into or upon. These features can increase the off-axis intensity at an angle larger from the optical axis within one or more planes. In a further embodiment, the incident light is directed through a total angle larger than one selected from the group consisting of 10 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees, 160 degrees. More than one surface feature region may be used. In a further embodiment, the optical efficiency of the system is increase through the use of surface relief features to the increased coupling into the film due to the reduced angle of incidence. In one embodiment, the transmission of the surface relief region is greater than one selected from the group consisting of 80%, 85%, 90%, 94%, 96% as measured according to ASTM D1003 with the light incident on the relief surface. In one embodiment, the transmission of the surface relief region combined with the volumetric anisotropic region is greater than one selected from the group consisting of 70%, 80%, 85%, 90%, 94%, 96% as measured according to ASTM D1003 with the light incident on the relief surface.
Improved Light Fixture Properties
In one embodiment, the spatial luminance uniformity is increased. This uniformity, measured as % non-uniformity, may be less than 70%, 50%, 30%, 20%, 10%, or 5%. In another embodiment, the spatial luminance uniformity is greater along one axis than a second axis. The asymmetric uniformity can allow increased optical efficiency by reducing the un-necessary diffusion for elements, components, or fixtures that are linear or other predetermined shape. This can create fixtures with increased spatial luminance along a predetermined axis, thus making the component or system more efficient due to the more efficient control of light delivery. In a further embodiment, the uniformity of illumination when using substantially collimated light sources is greatly increased. Similarly as above, the spatial luminance color uniformity can be improved when using non-uniform color light sources or arrays of light sources such as red, green and blue LED's. In one embodiment, the spatial luminance color uniformity is increased such that the Δu′v′ (calculated according to VESA flat panel display measurement Standard Version 2.0) is less than 0.2 across the angular profile containing the FWHM of illumination. In a further embodiment, the Δu′v′ is less than one selected from the group consisting of 0.1, 0.04, 0.02, 0.01. The uniformity of a fixture using a two-dimensional array of light sources that would normally have a two-dimensional non-uniformity pattern can be improved to have increased luminance or color uniformity along one or more axes. In one embodiment, the non-uniformity asymmetry ratio (measured by the ratio of the non-uniformities) is less than 2 or 5 or 10 or 30 or 50 or 80 for either the luminance non-uniformity or the ratio of the Δu′v′ along two axes.
In a further embodiment of this invention, the illuminance uniformity is increased. The illuminance uniformity, measured as % non-uniformity, may be less than 70%, 50%, 30%, 20%, 10%, or 5%. In another embodiment, the illuminance uniformity is greater along one axis than a second axis. The asymmetric illuminance uniformity can allow increased optical efficiency by reducing the un-necessary diffusion for elements, components, or fixtures that are linear or other predetermined shape. This can create fixtures with increased luminance along a predetermined axis, thus making the component or system more visible and have regions of increased luminance. In a further embodiment, the uniformity of a fixture using a two-dimensional array of light sources that would normally have a two-dimensional non-uniformity pattern can be improved to have increased uniformity along one or more axes. In one embodiment, the non-uniformity asymmetry ratio (measured by the ratio of the non-uniformities) is less than 2 or 5 or 10 or 30 or 50 or 80.
The illuminance color uniformity can be improved when using non-uniform color light sources or arrays of light sources such as red, green and blue LED's. In one embodiment, the illuminance color uniformity is increased such that the Δu′v′ (calculated according to VESA flat panel display measurement Standard Version 2.0) is less than 0.2 across the angular profile containing the FWHM of illumination. In a further embodiment, the Δu′v′ is less than one selected from the group of 0.1, 0.04, 0.02, and 0.01. The color uniformity of a fixture using a two-dimensional array of spatially varying colored light sources that would normally have a two-dimensional non-uniformity pattern can be improved to have increased luminance or color uniformity along one or more axes. In one embodiment, the non-uniformity asymmetry ratio (measured by the ratio of the non-uniformities) is less than 2 or 5 or 10 or 30 or 50 or 80 for either the luminance non-uniformity or the ratio of the Δu′v′ along two axes.
Air-Base Waveguide
In one embodiment of this invention, an air-based waveguide is utilized with a volumetric diffuser in order to provide increased transmission through the waveguide and reduced component cost and weight. In a further embodiment, more light is directed along the optical axis from the light source due to reflections off of the polymer based structure or matrix due to a higher refractive index. In one embodiment, the refractive index greater than 1.48 or 1.53 or 1.587 or 1.67 such that a more significant grazing incidence reflection occurs. In a further embodiment of this invention, the air-based waveguide reduces the percentage of light transmitted into a film or component by increasing the reflectance. As a result, the component can provide controlled transmission as well as controlled reflection. In one embodiment, the increased reflection re-directs a portion of the incident light such that the uniformity is increased along one or more axes, planes, or within a predetermined region of the surface emitting area of the fixture or solid angle of illumination.
Off-Axis Light Redirection
In one embodiment of this invention, the light is incident at an angle onto the light redirecting component comprising a volumetric anisotropic diffuser such that a virtual image of the source is created. The image can be created by surface relief features, or volumetric anisotropic diffusion such that the high luminance along one or more axis suggests that the light emitting source is directly behind the component when viewed. As a result, the fixture has the appearance of an increased luminance light fixture. In one embodiment, the anisotropic diffuser scatters light such that the light is re-directed by an greater than one selected from the group of 10 degrees, 20 degrees, 40 degrees, 60 degrees, 90 degrees, 120 degrees.
Radial Light Re-Direction
In one embodiment of this invention, an anisotropic volumetric diffuser is used to scatter the incident light along a radial direction by using either a curved anisotropic region or a curved light source or array of light sources. In one embodiment, the anisotropic diffuser is positioned and shaped such that it is substantially parallel to the major optical axis. Typically, incident light from substantially collimated sources reaching an anisotropic diffuser will scatter light into an illumination pattern that is not symmetric or spatially uniform. The radial symmetry from the radial output of the light source and the radial symmetry of the curved anisotropic diffuser can create a more symmetric, and optically efficient light output pattern. Similarly, a curved array of light sources used with a curved anisotropic volumetric diffuser can create an efficient light pattern of a desired shape or a desired spatial luminance pattern.
Clarity
In one embodiment of this invention, the clarity of the MNOC is improved such that the optical transmission is increased and the virtual image has increased clarity. The clarity can be greater than 20%, 50%, 70%, 90% or 95%.
Examples
The pendant light fixture of FIG. 1 contains 3 primary optical components utilized in providing control of light distribution in 3 axes; x, y, and z. The substantially collimated light source 11 is created from the LED 12 and the collimating reflector 13 . The multi-functional non-imaging optical component 14 is disposed in a cylindrical shape parallel to the optical axis and is contained within a transparent support tube 15 . The collimated light source may have a beam angle of less than 120 degrees. Illustrated in the drawing is an MR16 lamp containing multiple LEDs with beam angles of ten degrees. Versions of MR-16 lamps are commercially available with a wide range of beam angles, both with LED light sources utilizing primary and/or secondary optic collimating lenses or as incandescent (including halogen) light sources with parabolic type reflectors for collimation. MR-16 lamps are well suited for pendant fixtures as they provide a small point light source and their standard package size of lamp plus reflector is approximately 2 inches in diameter.
The Multifunctional Nonimaging Optical Component (MNOC) 14 performs multiple functions, including but not limited to control over the luminance of the fixture as well as the illumination output (illuminance). It can contain surface relief features on one or more surfaces, may be a combination of optical films and may contain volumetric anisotropic or isotropic optical regions or components. Volumetric anisotropic diffusers, the different types and methods of creation are described in U.S. patent application Ser. Nos. 11/282,551 and 60/870,262, the entire contents of which are incorporated herein by reference. The MNOC may function as an air-core waveguide designed to internally reflect light 18 along the optical path. This light 18 combines with the direct light 17 from the substantially collimated source 11 to contribute to the light directed downwards. The portion of the light 16 incident on the MNOC that is anisotropically scattered into larger angles from the optic axis provides output radial to the optical path of the collimated light source(s) which can be controlled in intensity and distribution orientation by the use of a diffuser. The diffuser may have asymmetric properties that not only control the photometric distribution of light from the fixture but also control the visual appearance of the light fixture. The illustrated example of FIG. 1 contains a highly asymmetric volumetric diffusing film with anisotropic beam angles of approximately 50 to 1 as measured with an essentially perfectly collimated green laser light source of 532 nm wavelength. In this embodiment the diffuser is oriented with the larger diffusion axis oriented parallel to the optical path. In this orientation, light 16 that exits radially is preferentially scattered in an upward and downward orientation. This is also illustrated in the embodiment of FIG. 2 by an angled view. The substantially collimated light source 21 is created from the LED 22 and the collimating reflector 23 . The first multi-functional non-imaging optical component 24 is disposed in a cylindrical shape parallel to the optical axis (similar to 14 in FIG. 1 ) and is contained within a transparent support tube 25 . The anisotropically scattered light profile 26 creates increases the linear uniformity while providing illumination from the fixture into larger angles from the optical axis. This is useful in providing more uniformly lighting a space, reducing contrast caused by light and dark zones of illumination, and reducing glare. In this embodiment the diffuser is in the form of a polymer film which is curled into a cylinder shape and fitted inside a clear polymer tube. Alternatively, the clear tube can be eliminated and the diffuser film itself can form a desired waveguide shape. The shape of the waveguide is illustrated as an open ended cylinder but a number of other shapes substantially tubular in nature are possible such as rectangular tubes, curved tubes, and tubes deviating in direction from the center of the optical path. Other forms and methods for created the shape during the production or post forming of the diffuser can be used such as those understood in the polymer and plastic forming industry. Varying the shape and dimensions of the MNOC provides control of the light output of the fixture. The diameter or length of the component can increased to provide tailored optical luminance or color properties or specific illuminance properties.
The asymmetric diffusion properties of the MNOC 14 create a unique visual image when viewed as part of the light fixture. The image of the light source(s) is extended along the optical path, appearing more tightly concentrated along the centerline of the MNOC 14 as the distance from the light source increases (tapers if off-axis). Asymmetric diffusers with extremely low diffusion in one axis provide the MNOC 14 with substantially high clarity enabling the interior of the MNOC to be visible but appearing stretched in one dimension. If multiple light sources are used each form creates a separate image. If multicolor LEDs are used, each LED creates a separate linear image of differing color providing a useful aesthetic effect for some applications.
In one embodiment of this invention, more than one MNOC is used to provide a specific light output distribution. Additional lenses or MNOC's may optionally be added anywhere along the optical path to further control the light distribution and appearance of the light fixture. As illustrated in FIG. 2 , a second MNOC 27 positioned at the end of the tube 25 farthest from the light source to serves not only as an optical lens but an end cap for the tube 25 to prevent dust and internal contamination. In the illustrated embodiment of FIG. 2 this MNOC 25 may contain an anisotropic diffuser to provide beam shaping of the light output that propogates the entire length of the tube 25 . A lens positioned at the other end of the tube 25 closest to the collimated light source 21 can be used to control the image of the light source that become asymmetrically elongated in appearance by the MNOC 27 . This gives greater control over the visual appearance of the light fixture and improves the light output pattern while providing a controlled increase in uniformity in a linear direction parallel to the tube 25 .
The wall sconce light fixture of FIG. 3 contains components utilized in providing control of light distribution in 3 axes; x, y, and z. Light from a linear array of LED's 32 is incident on the major wall surface of the sconce 32 and the top and bottom surfaces containing MNOC's 33 . The desired optical output of a wall sconce varies depending on specific application but the illustrated example is configured to provide distributions generally useful in wallwashing type applications. Two sets of optical systems are shown oriented with optical paths facing in opposite directions. These can be substantially different to provide unique and differentiated products.
FIG. 4 and FIG. 5 show a pendant light fixture embodiment with a LED light source 42 within a collimating light source 41 in which the light redirecting region 45 is optically coupled to a light transmissive wall 44 with a portion of the light transmissive wall having no optical coupling to the light transmissive wall. In the uncoupled section, light from example optical path A enters the light transmissive wall and is propagated within the light transmissive wall by total internal reflection. When the light enters a light redirecting region, a portion of the light is scattered and exceeds the critical angle of total internal reflection, causing a light outcoupling portion 46 a to outcouple out of the light fixture. Some of the light continues to propagate by internal reflection and subsequently outcouples in a different area of the light redirecting region, for example the light outcoupling portion 46 b . A portion of the light on example optical path A propagates out the end of the light transmissive wall as light output portion 47 . Light on example light path B is reflected within the collimating light source 41 and then propagates through the optical cavity 51 without further reflection and outputs as example light output portion 48 . In one embodiment, the light redirecting region is applied to the light transmissive wall as a coating of comprising regions of differing index of refraction. The light transmissive wall can be comprised light transmitting material such as optically clear polymer or glass. Acrylic, polycarbonate, polyurethane, and silicone are example of common optically clear polymers.
FIG. 6 and FIG. 7 show a light fixture embodiment feasible for use as either a downlight or a pendant. The light transmissive wall 44 forms a bulb shape. A LED light source 42 is located within a collimating light source 41 . The light redirecting region 45 is optically coupled to a light transmissive wall 44 with a portion of the light transmissive wall having no optical coupling to the light transmissive wall. In the uncoupled section, light from example optical path A enters the light transmissive wall and is propagated within the light transmissive wall by total internal reflection. When the light enters a light redirecting region, a portion of the light is scattered and exceeds the critical angle of total internal reflection, causing a light outcoupling portion 46 a to outcouple out of the light fixture. Some of the light continues to propagate by internal reflection and subsequently outcouples in a different area of the light redirecting region, for example the light outcoupling portion 46 b . A portion of the light on example optical path A propagates out the end of the light transmissive wall as light output portion 47 . Light on example light path B is reflected within the collimating light source 41 and then propagates through the optical cavity 51 without further reflection and outputs as example light output portion 49 after diffusing in the light redirecting region. In one embodiment, the light redirecting region is applied to the light transmissive wall as a coating of comprising regions of differing index of refraction. The optical cavity 51 is typically filled with air but other light transmissive gases or a vacuum are possible substitutes.
FIG. 8 shows an alternative embodiment of FIG. 6 and FIG. 7 in which the light transmissive wall forms a bulb shape which provides some light guiding effect on light output portion 50 .
FIG. 9 shows an alternative embodiment in which the light redirecting region optically coupled to the light transmissive wall is patterned. This can be done for aesthetic reasons, to provide more uniform luminance, or to give further control of light distribution output.
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A novel light fixture comprises a light source, a collimating element, an optical cavity and a multi-functional non-imaging optical component to control light distribution. The present invention provides a system and method of controlling the output of light from a light fixture. One or more volumetric anisotropic diffusing components can be utilized to control both the photometric distribution and visual appearance of the light fixture. A high degree of optical control is obtained with durable components that can be easily customized to optimize optical performance in light fixtures designed as pendants, wall sconces, wallwashers, downlights, and tasklights. The luminance and color uniformity as well as the illuminance and color uniformity of illumination can be controlled and improved.
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This is a continuation-in-part of Ser. No. 791,444, filed Apr. 27, 1977, now abandoned, which is in turn a continuation of Ser. No. 500,782, filed Apr. 26, 1974, also abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in electrochemical cells or batteries and more particularly to zinc halogen cells or to batteries of cells preferably using chlorine as the halogen and excluding fluorine but it may be iodine or bromine preferably in gaseous form. Such a cell or battery may be as described in United Kingdom Letters Patent Specification No. 1,258,502, U.S. application Ser. No. 804,215, now U.S. Pat. No. 4,105,829.
2. Description of Prior Art
British Pat. No. 1,258,502, U.S. application Ser. No. 804,215 describes a cell or a battery of cells, the cell comprising a casing, a porous halogen storing electrode forming the cathode, a zinc bearing electrode forming the anode, the electrode being immersed in a liquid zinc halide electrolyte solution, a halogen gas inlet to the casing, a gas flow-path in the casing from the gas inlet to the interstices of the halogen storing electrode, and positive and negative electric conductors leading from the electrodes to terminals accessible to the outside of the casing. The cell is in a halogen gas circuit including a halogen gas cylinder, a pressure regulated valve to control the flow of gas from the cylinder to the casing interior, an ultra violet lamp for the removal of undesirable gases such as hydrogen from the circuit, and a halogen gas liquifier connected to the cylinder, the latter being in the circuit between the valve and the liquifier. An aqueous return may be provided from the liquifier to the cell to return water, which normally has other constituents, into the cell or battery electrolyte. The porous carbon electrode acting as a cathode is made up of a number of electrode structures each comprising a substrate of anodizable metal selected from the metals of Group IV(A) and Group V(A) of the Periodic Table according to Mendeleef having permanently associated therewith at least one coherent stratum of substantially porous carbon. The preferred anodizable metal is titanium. The substrate is preferably in the form of an open mesh such as expanded metal, an apertured sheet of the metal or a porous sheet of the metal having a pore size for example of 3-25 thousandths of an inch diameter, and perferably having a pore size larger than the size of the carbon particle in the crumb, which is the preferred form of the carbon particles and binder. When titanium is used, it is preferable to use titanium of commercial purity having mechanical hardness of I.M.I cp 115 or 130. Zinc bearing electrode forming the anode may be formed by a titanium mesh as for the cathode which is coated or otherwise treated with zinc. The crumb is pressed onto the substrate at a pressure of at least 2 tons psi.
The cathode may be made up of the electrode structure, the spaces in each cathode between adjacent cathode structures being used to supply the chlorine gas to the surfaces of the porous carbon of the structure.
In such a cell or battery during discharge the halogen e.g. chlorine in gaseous form, is supplied to the cathode from the external storage system and on recharging, the halogen gas is liberated on the surfaces of the cathode, rises to the surface of the electrolyte, escapes or is removed from the cell casing, compressed and stored for reuse in a subsequent cycle. The gas may be treated to remove hydrogen and other impurities before it passes to the storage capacity. In operation the halogen gas if frequently wet which necessitates the use of materials inert to the corrosive gas for making the ancillary equipment such as ducts and storage capacities, e.g. high pressure cylinders used in the aforesaid cells or batteries.
It has been found in operating such cells under an internal pressure equal to atmospheric pressure the cell is polarisation limited in output due to the diffusion rate limitation of the halogen e.g. chlorine into the electrolyte solution.
The main object of the present invention is to provide a cell or battery of the zinc halogen type in which the power to weight ratio is increased.
It is known that the solubility of chlorine gas in zinc chlorine solution is a function of the temperature and pressure in the space within which the halogen and zinc chloride are contained, so that an increase in pressure within the space permits a greater concentration of the chlorine in solution where it becomes the active cathode. It is also known that solvents exist for the halogens which exhibit this function at ambient temperatures and pressures, suitable solvents for chloride for example being carbon tetrachloride and sulphuryl chloride and such solvents can be in liquid or solid form. It is also known that chlorine gas at normal atmospheric temperatures e.g. 2°-28° C. is liquified at a pressure of about 75 lbs/sq.in but at any pressure above 148° C. chlorine is unliquifyable.
SUMMARY
According to the present invention a rechargeable zinc halogen electric current producing cell comprising a casing, at least one gaseous halogen cathode support structure within said casing and formed of a substrate of anodizable metal or alloy selected from the metals of Groups IVA and VA of the Periodic Table according to Mendeleef having permanently mounted thereon a coherent stratum of crumb-like porous carbon, a zinc containing anode within said casing, a separator in said casing separating said cathode support structure and said anode to prevent cathodic halogen molecules contacting said anode but permitting the passage of halogen ions, a zinc halide electrolyte within said casing in substantial surface contact with said gaseous halogen in said cathode support structure and with said anode, the internal casing temperature and pressure being such as to maintain said halogen in a gaseous state at any pressure in excess of two atmospheric pressures with a minimum temperature within said casing of 2° C. and a halogen circuit including means for storing said gaseous halogen liberated at said cathode support structure on recharge and means to supply gaseous halogen to said cathode support structure on discharge.
DESCRIPTION OF PREFERRED EMBODIMENTS
Preferably the cell is operated at a pressure between 2 and 10 atmospheres.
The halogen e.g. chlorine may be contained either in solution in the electrolyte or in any solvent present in addition to the electrolyte and such cells may be operated at elevated pressures in excess of atmospheric pressure up to pressures of several atmospheres providing the halogen remains in gaseous form except where dissolved.
The cell may include a solvent for the halogen, a suitable solvent being carbon tetrachloride or sulphuryl chloride although any halogen solvent may be used which is inert to the constituents of the cell. Where the halogen solvent is employed, this may be contained in cavities in the cathode support structure.
Means may be provided to agitate as by stiring the electrolyte to assist in the diffusion of the ions into and out of contact with the porous carbon of the cathode support structure during cell operation.
Any of the metals of the Groups IVA and VA of the Periodic Table according to Mendeleef or any alloys of them may be used, the preferred metal is titanium since that is the most readily available and the least expensive. It is preferably used in open mesh or expanded metal form. The porous carbon is preferably formed as described in U.S. Ser. No. 839,057 filed Oct. 3, 1977, now U.S. Pat. No. 4,166,870 so that it is of a crumb-like formation having a myriad of voids in which the gaseous halogen e.g. chlorine makes gas-liquid contact with the zinc halogen electrolyte. By using pressure-temperature conditions within the casing which while maintaining the halogen in gaseous condition, the pressure should be in excess of 2 atmospheres but preferably not in excess of 10 atmospheres thereby increasing the solubility of the chlorine in the electrolytes. In addition due to a lowering of the surface tension between the gaseous chlorine and the liquid electrolyte a larger solid liquid gas interface or reaction-zone is created significantly reducing the electrode impedance and permitting greater electrical output. The minimum temperature with the casing is about 2° C. Moreover the cell performance increases as the pressure rises and as a result the halogen tends to be more miscible with the electrolyte. There is an optimum pressure of cell operation at any temperature and electrolyte concentration and therefore a conventional sensor means is preferably provided in the cell to control the pressure so that despite variations of these parameters the pressure is maintained at the optimum value.
The halogen cathode storage structure and the anode must be kept separate to prevent contact of halogen gas with the anode and any suitable separator may be employed which is made of material impervious to halogen molecules but permits halogen ions to pass in the electrolyte operation on charge and discharge of the cell.
Since the chlorine attack on the zinc anode must be contained it is preferred to construct the cell so that the pressure is equalised on both sides of the separator. This is achieved by making the separator sufficiently flexible to accommodate any pressure difference on its opposite i.e. cathodic and anodic sides: alternatively a liquid non-miscible to the electrolyte and non-reactive to the halogen and having a low solubility to chlorine such as fluorinated hydrocarbons e.g. dichlorodifluoromethane may be floated and maintained over the surface of the electrolyte surrounding the anode which must be completely immersed in the electrolyte so that the zinc anode will be immune to chlorine attack. In such cases the separator need not divide the cell hermetically into two compartments containing the cathodic and anodic sides of the cell.
The cell casing may have a halogen outlet and inlet communicating with a halogen storage capacity inside or outside the casing. The heads of the cathodes where several cathodes are used may be interconnected by suitable manifolds or ducting or passages leading to and from the cathodes and the halogen storage capacity within or exterior to the cell casing.
While the halogen during charge may be liberated on the outer side of the cathode and/or within the hollow interior of a hollow cathode, means should be provided to collect the halogen and pass it to the storage capacity and when the storage capacity operates under elevated pressure a solvent for the halogen may be incorporated in the halogen storage capacity. Such storage capacity may retain the halogen at high pressures with or without a solvent for the halogen and the halogen may be retained in the storage capacity as liquid halogen.
The halogen storage capacity may be external to the cell casing and receive the halogen from the cell under pressure generated by electrolysis during charge or recharge, and deliver it through cavity type electrodes to the porous carbon surfaces thereon during discharge.
If desired means may be provided, such as a mechanical stirring mechanism, for stirring up the chlorine solvent within the cell thus assisting in the diffusion of the chlorine into or out of the cell or within the cell.
Also if desired an emulsifying agent may be provided in the cell to aid emulsification of the halogen e.g. chlorine solvent with the electrolyte whether it is in liquid or gelled form.
In one embodiment of the invention the cells are each made with head spaces above the electrolyte and above or forming part of the chlorine electrode, i.e. the cathode, and in an assembly of cells to form a battery these head spaces may be connected together with a manifold. This manifold may form a chlorine storage space or be connected to a separate chlorine storage space disposed in the cell, or outside the cell.
Such a storage space may contain the chlorine solvent and the whole cell system operates under pressure of 1 to 10 atmospheres providing that the chlorine within the cell casing is in gaseous form.
Where the chlorine storage capacity is external to the cell, either in the casing or outside the casing, the chlorine may be passed to the storage space from the cell by a pump or through a non-return valve, the chlorine pressure being generated by electrolysis during charge. During discharge the chlorine is delivered from the storage capacity through the cathodes which are formed with an internal cavity to receive the gas and permit it to pass through the porous carbon of the cathode to the outside thereof.
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A zinc halogen cell having a zinc containing anode and a halogen consuming cathode, comprising a casing capable of withstanding above atmospheric pressure within which the cathode and anode are disposed and containing a zinc halide solution electrolyte incorporating means for storing the halogen liberated at the cathode on recharge and for supplying the halogen to the cathode on discharge.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. Ser. No. 12/718,739, filed Mar. 5, 2010, now allowed, which is a divisional of U.S. Ser. No. 12/115,416, filed May 5, 2008, now U.S. Pat. No. 7,691,644, issued on Apr. 6, 2010, which is a divisional of U.S. Ser. No. 10/948,358, filed Sep. 22, 2004, now U.S. Pat. No. 7,378,285, issued on May 27, 2008, which claims priority benefit of U.S. Provisional Application No. 60/505,092, filed Sep. 22, 2003. The contents of these applications are incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to an assay for detecting and differentiating multiple analytes, if present, in a single fluid sample, including devices and methods therefor.
BACKGROUND OF THE INVENTION
[0003] The field of rapid diagnostic testing has evolved for many years to permit the detection of analytes in a variety of sample types. The use of polyclonal antibodies was followed by the use of monoclonal antibodies to generate assays with high specificity for a number of analytes, including hormones, blood cells, drugs and their metabolites, as well as the antigens of infectious agents including Strep A, Strep B, Chlamydia, HIV, RSV, influenza A and influenza B and many others. The visible signal generated by enzyme-catalyzed reactions or by the accumulation of a visible signal at the level of a test line has also resulted in rapid development of highly sensitive results. Many of the rapid immunoassay-based tests include a solid housing encasing a test strip. However, recently, immunochromatographic assays have been manufactured which do not have solid housings. Such tests, referred to as dipsticks, can be dipped directly into a tube containing a pre-determined amount of the liquid sample of interest. The extremity of the dipstick containing a sample-receiving pad is generally brought in contact with a liquid sample, and the liquid migrates up the flow path. Advantages of the dipstick format include ease of use and minimum handling, which reduces the opportunities for contamination and procedural errors, and lowers manufacturing costs.
[0004] One disadvantage of current immunochromatographic dipsticks is that they can only detect the presence of a single analyte. Often these devices are limited because there is no provision to mark the location of possible multiple test lines along the flow path. In the field of chemical urinalysis, dipsticks carrying multiple pads, each specific for a urine analyte to be detected and measured, the dipstick is dipped into the urine sample, then removed from the container, blotted to eliminate excess urine, and applied against a template in order to read the results. These devices are capable of evaluating multiple analytes, but are problematic. For example, such devices increase the chances of contamination by carry-over of material from one device to another, with the consequence of potentially inaccurate results. Moreover, this format exposes the user to potential contamination via removing the strip from the urine sample, blotting it on an absorbent paper, which becomes contaminated, applying it against the template, which often is the exterior wall of the product container, thereby contaminating the product package itself. Further, as indicated, an external template is required to read results.
[0005] It is recognized in a variety of fields that the use of single analyte rapid tests is often limiting, for example, because only one analyte at a time can be evaluated. The advantage of rapidity is therefore challenged by the limitation of current assays as adjuncts to the diagnosis of a disease state. For instance, the pediatric units have to make differential diagnostics of Flu A, Flu B, RSV and other upper respiratory viruses, on infants that are in need of urgent care. The availability of rapid test panels would greatly facilitate the doctors' efforts to diagnose the condition, and therefore to take the appropriate course of action faster, more easily, and at lower cost. To date, no such assay has been developed that allows the differential diagnostic of two or more analytes on a single test strip, in a minimally involving procedure.
[0006] In summary, chemical urinalysis dipstick assays have been used for many years to determine the presence (or amount) of multiple analytes in a urine sample; however, the technology used to perform such assays not only has undesirable use characteristics but is not readily transferable to immunologic based assays (dipstick or lateral flow) which require flow of sample through the assay device rather than immersion of the device (in particular immersion of the test portion of the device) into a sample. For example, with respect to the use of chemical urinalysis dipsticks, the fact that they must be submerged into the urine sample, removed and blotted of excess urine then placed in physical contact (or very close proximity) with an external, typically reusable (and hence contaminable), test results panel (i.e., template) is not just undesirable but unsafe, particularly if the sample contains contagious agents such as virus or bacteria. Further, because immunologic based assays typically employ at least two, generally sequential reactions (for example a labeling followed by a capture (test) reaction), they are not amenable to submersion into a sample in the same manner as the chemical urinalysis dipsticks. Thus, there is a need in the art for devices and methods that addresses these problems in the art. The present invention addresses these and other related needs in the art.
SUMMARY OF INVENTION
[0007] The present invention provides analytical devices, particularly immunoassay devices, capable of determining the presence and/or amount of multiple analytes in a fluid sample, permitting more complete diagnosis or analysis of said sample. Advantageously, the present devices may be formatted as dipsticks or lateral flow devices, in either case not requiring an external test results panel for determination of test results. By positioning the multiple test and/or control zones in predetermined patterns on the test devices in accordance with the present invention, the need for an external test results panel, or even markings on a test device housing, is eliminated. By way of example, in a preferred embodiment, a single control zone is positioned between two test zones, each test zone testing for the presence or amount of a different analyte. It has heretofore been assumed that a control zone must be located downstream of a test zone in order function as control zone. However, the present inventors have discovered that such is not necessary and, rather, that one or more control zones may be employed in immunoassay devices not only to provide an indication of assay completion and/or operability but also of the relative location of one or more test lines, thereby permitting rapid differentiation of analytes within a fluid sample in a single immunoassay test device.
[0008] In an embodiment of the present disclosure, a device is provided for the detection of multiple analytes in a fluid sample, which device comprises: a matrix defining an axial flow path, the matrix comprising: i) a sample receiving zone at an upstream end of the flow path that receives the fluid sample, ii) a label zone positioned within the flow path and downstream from the sample receiving zone, said label zone comprising one or more labeled reagents which are capable of binding one or more analytes to form labeled analytes and are mobilizable in the presence of fluid sample, iii) one or more test zones positioned within the flow path and downstream from the label zone, wherein each of the one or more test zones contain means which permit the restraint of a different labeled analyte in each test zone or a combination of different labeled analyte in a single test zone, and wherein restrained labeled analyte is detectable within each test zone, and iv) one or more control zones positioned within the flow path and downstream from the label zone, wherein the one or more control zones incorporate means which permit the indication of the completion of an assay. In the most frequent embodiments, the device incorporates means to restrain and thereby detect two or more different labeled analytes in a sample. Also, in frequent embodiments, the device comprises a dipstick assay device. In occasional embodiments, the device comprises two or three or more test zones and two or more control zones.
[0009] The present device permits the detection of multiple analytes in a sample without reference to an external template. Moreover, frequently the device comprises a dipstick assay that lacks an external housing. In general, the analytes comprise analytes of interest and further comprise those provided herein, among others. Frequently, the present devices are useful for assaying a particular panel of analytes. Also frequently, the present devices are useful to simultaneously detect two or more different analytes in a sample. On occasion the present device and methods are useful to detect a panel of analytes of interest selected from an influenza panel (comprising test zones containing reagents capable of restraining a selection of influenza A, influenza B, respiratory syncytial virus (RSV), adenovirus, rhinovirus and/or parainfluenza virus), a panel comprising one or more of streptococcus pneumoniae, mycoplasma pneumoniae and/or Chlamydia, an HIV panel, a Lupus panel, an H. Pylori panel, a toxoplasma panel, a herpes panel, a Borrelia panel, a rubella panel, a cytomegalovirus panels, a rheumatoid arthritis panel, or an Epstein-Barr panel, among others.
[0010] In one preferred aspect. each of the one or more test zones lie in fluid communication with one another. Moreover, in another aspect, the one or more test zones lie in fluid communication with one or more control zones. In a further aspect, the presently contemplated devices do not utilize one or a plurality of wells, rather a matrix defining an axial flow path is utilized. In a frequent embodiment, a device in accordance with the present disclosure contains a single sample receiving zone that lies in fluid communication with the one or more test zones.
[0011] In frequent embodiments, the control zone is positioned between the one or more test zones. In occasional embodiments, the positioning of the control zone between the one or more test zones comprises positioning one control zone between two test zones. Also in occasional embodiments, the positioning of the control zone between the one or more test zones comprises multiple test zones and multiple control zones, wherein each control zone is positioned between two test zones, in an alternating arrangement. Frequently, the control zone is positioned upstream of a test zone. Also frequently, the control zone is positioned downstream of a test zone. In occasional embodiments, the control zone is positioned downstream of each or all of the one or more test zones. In another embodiment, the test and control zones are positioned in an alternating format within the flow path beginning with a test zone positioned upstream of any control zone.
[0012] In one embodiment, each of the one or more test zones contain means comprising an immobilized reagent capable of specifically binding a unique analyte. Thus, in this embodiment, each of the one or more test zones contain an immobilized reagent capable of specifically binding a particular analyte, wherein each of the immobilized reagents is capable of binding a different analyte than any other immobilized reagent within another test zone in the device. These means can comprise any of a variety of specific binding pair members as described elsewhere herein. On occasion, the means which permit the restraint of a different labeled analyte in each test zone comprise an immobilized capture reagent.
[0013] In one aspect, the test zones can be provided in any of a variety shapes and configurations with the limitation that each particular test zone is detectably distinguishable from other test zones, if present, and the control zone(s) in the presence of labeled analyte, if present, restrained in that test zone. In a related aspect, the control zones can be provided in any of a variety shapes and configurations with the limitation that each particular control zone is detectably distinguishable from other control zones, if present, and the test zones upon completion of an assay.
[0014] In another embodiment, the label zone comprises multiple labeled reagents, wherein each of the multiple labeled reagents is capable of specifically binding a unique analyte. In occasional embodiments, the labeled reagent is a reagent capable of binding any or all of the multiple analytes, if present, in the sample. Frequently, each of the labeled reagents is detectably distinguishable from one another. Also frequently, the label component of the labeled reagent is selected from the group consisting of a chemiluminescent agent, a particulate label, a colloid label, a colorimetric agent, an energy transfer agent, an enzyme, a fluorescent agent and a radioisotope. In occasional embodiments, the labeled reagents comprise different colored labeled reagents. For example, the labeled reagent can comprise 2, 3, 4, 5, or 6 or more different colored particulate reagents. Particulate label colors comprising red, blue, black, purple, and other high-contrast colors are frequently utilized in the present embodiments. In frequent embodiments, the colored particulate label comprises a colored latex particulate label. In another frequent embodiment, the colored label comprises a Carbon, Gold or Selenium colored colloid label. On occasion, the use of different colored particulate labeled reagents allows for the detection of multiple analytes via the observation of different detectable signals (e.g., different colors) in any one or more of the one or more test zones as a result of the restraint of different labeled analyte in each test zone. In a less occasional embodiment, the labeled reagent can comprise a mixture of any of a variety of detectable labeling schemes in one device such that each analyte can become labeled by a different labeled reagent to provide a different detectable signal.
[0015] In occasional embodiments, a test zone may contain one or more immobilized reagents capable of specifically binding a unique analyte, such that multiple labeled analytes may become restrained and detectible in the test zone. In this embodiment there may be multiple analytes of interest for the device, however, frequently only one of these analytes is present, if at all, at one time in the fluid sample. Thus, multiple labeled reagents are useful in this embodiment which are both analyte specific and detectably distinguishable (i.e., different colors). For example, a device of the present embodiment is capable of detecting Influenza A or influenza B antigen, if present, in a single sample. In the case of influenza A, a red-colored labeled reagent that is capable of specifically binding influenza A may be used, which would result in the development of a red-colored test zone after completion of the assay of a fluid sample containing influenza A analyte. In the case of Influenza B, a blue-colored labeled reagent that is capable of specifically binding influenza B may be used, which would result in the development of a blue-colored test zone after completion of the assay of a fluid sample containing influenza B analyte. One of skill in the art would recognize that the colors may be alternated and/or other detectibly distinguishable labeling means contemplated herein may be utilized. Frequently, such test zones can be deposited as single zones containing a mixture of capture reagents, or as adjacent zones of single capture reagents. On occasion, in the present embodiment, multiple analytes of interest are present together in the fluid sample, which then become labeled subsequent to contact with the device and restrained in the test zone. Thus, multiple labeled analytes may be restrained in a single test zone.
[0016] In another embodiment, the sample receiving zone and the label zone comprise separate components in fluid-flow contact. In a frequent embodiment, the one or more test zones and the control zone are positioned within a test region. Moreover, frequently, the sample receiving zone, label zone and the test region comprise separate components in fluid-flow contact. Also frequently, the test region comprises nitrocellulose or other material suitable for immobilization of test and control reagents, and/or is laminated on a plastic backing material. On occasion, the matrix is positioned within a housing comprising a support and optionally a cover, wherein the housing contains a sample-receiving aperture and one or more observation ports. In occasional embodiments, the control zone comprises a mark that is detectable within the test region when the test region is in a moist state. In this embodiment the test region comprises a material that is opaque in a dry state and transparent in a moist state such that the mark become visible as the liquid sample moistens the test region.
[0017] In a further embodiment, the device is capable of detecting influenza A and/or influenza B, if present, in a single sample. In occasional embodiments, each of the multiple analytes are selected from the group consisting of a toxin, an organic compound, a protein, a peptide, a microorganism, a bacteria, a virus, an amino acid, a nucleic acid, a carbohydrate, a hormone, a steroid, a vitamin, a drug, an antibody, and a hapten.
[0018] In another further embodiment, the number of control zones is represented by the variable “n” and the number of test zones is represented by the variable “n+1,” and wherein the test zones and control zones are positioned in a series comprising an alternating format, wherein the zone arranged at the most downstream position in the series comprises a test zone. The variable “n” often refers to 2 test zones. However, on occasion, the variable “n” refers to between 2 to about 5 test zones. Thus, on occasion, 2, 3, 4, 5 or more test zones are positioned on the device. Frequently, each of the test zones permit the restraint of a different analyte. On occasion, a device is provided that is capable of detecting a number of different analytes represented by the variable “n,” wherein the number of control zones and the number of different analytes capable of being detected by the device are equal. Also on occasion, a device is provided that is capable of detecting a number of different analytes represented by the variable “n+1,” wherein the number of test zones and the number of different analytes capable of being detected by the device are equal.
[0019] In frequent embodiments a device for the detection of multiple analytes in a fluid sample is provided, wherein the device comprises: a matrix defining an axial flow path, the matrix comprising: i) a sample receiving zone at an upstream end of the flow path that receives the fluid sample; ii) a label zone, within the flow path and downstream from the sample receiving zone, comprising a first and second labeled reagent, each of which specifically bind an analyte to form a labeled analyte and are mobilizable in the presence of fluid sample; and iii) a test region comprising a first test zone, a second test zone and a control zone, wherein the control zone is positioned between the first and second test zones within the flow path, wherein each of the first and second test zones contain means which permit the detection of a different analyte in each test zone, and wherein the control zone incorporates means which allow for the indication of the completion of an assay. In occasional embodiments, the first zone is positioned upstream from the control zone within the flow path and the second zone is positioned downstream from the control zone within the flow path.
[0020] In another embodiment, methods are provided for the detection of one or more analytes in a fluid sample. For example, a method is provided for the detection of multiple analytes in a fluid sample, comprising: i) contacting a device of the type described above with a fluid sample suspected of containing one or more analytes, and wherein each of the one or more test zones in the device contains means which permit the restraint of a different labeled analyte or combination of labeled analytes in each test zone; and ii) detecting one or more labeled analytes restrained in the one or more test zones. Frequently the device comprises a dipstick-type device. In general, the analytes of interest comprise those provided herein, among others. Frequently, the present methods are useful for assaying a particular panel of analytes. Also frequently, the present methods are useful to simultaneously detect two or more different analytes in a sample. Commonly the present devices and methods are utilized to diagnose a medical condition. Also commonly, the present devices and methods aid in guiding therapeutic decisions. On occasion, the present method steps may be practiced at different locations, and by different entities.
[0021] These and other features and advantages of the present invention will be apparent from the following detailed description, examples and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1(A-J) depicts various example configurations of the test and control zones within the presently contemplated devices. The arrow in each Figure indicates the general direction of fluid sample flow after initial contact with the device. The boxes containing vertical lines and/or the diagonal lines depict control zones, and the boxes containing crosshatched lines depict test zones. FIG. 1 (A-J) further depicts the sample receiving zone [1], the label zone [2] and the test region [3]. The present devices are not intended to be limited to the aspects indicated in the depicted embodiments, other configurations are contemplated. Moreover, the depicted aspects are not necessarily presented to scale.
[0023] FIG. 2 is a graph depicting the ratio of test zone and control zone signals for different volumes of sample in exemplary devices.
DETAILED DESCRIPTION OF THE INVENTION
[0024] For clarity of disclosure, and not by way of limitation, the detailed description of the invention is divided into the subsections that follow.
A. DEFINITIONS
[0025] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this invention belongs. All patents, applications, published applications and other publications referred to herein are incorporated by reference in their entirety. If a definition set forth in this section is contrary to or otherwise inconsistent with a definition set forth in the patents, applications, published applications and other publications that are herein incorporated by reference, the definition set forth in this section prevails over the definition that is incorporated herein by reference.
[0026] As used herein, “a” or “an” means “at least one” or “one or more.” The use of the phrase “one or more” herein does not alter this intended meaning for the terms “a” or “an.”
[0027] As used herein, “disease or disorder” refers to a pathological condition in an organism resulting from, e.g., infection or genetic defect, and characterized by identifiable symptoms.
[0028] As used herein the term “sample” refers to anything which may contain an analyte for which an analyte assay is desired. The sample may be a biological sample, such as a biological fluid or a biological tissue. Examples of biological fluids include urine, blood, plasma, serum, saliva, semen, stool, sputum, cerebral spinal fluid, tears, mucus, amniotic fluid or the like. Biological tissues are aggregate of cells, usually of a particular kind together with their intercellular substance that form one of the structural materials of a human, animal, plant, bacterial, fungal or viral structure, including connective, epithelium, muscle and nerve tissues. Examples of biological tissues also include organs, tumors, lymph nodes, arteries and individual cell(s).
[0029] “Fluid sample” refers to a material suspected of containing the analyte(s) of interest, which material has sufficient fluidity to flow through an immunoassay device in accordance herewith. The fluid sample can be used as obtained directly from the source or following a pretreatment so as to modify its character. Such samples can include human, animal or man-made samples. The sample can be prepared in any convenient medium which does not interfere with the assay. Typically, the sample is an aqueous solution or biological fluid as described in more detail below.
[0030] The fluid sample can be derived from any source, such as a physiological fluid, including blood, serum, plasma, saliva, sputum, ocular lens fluid, sweat, urine, milk, ascites fluid, mucous, synovial fluid, peritoneal fluid, transdermal exudates, pharyngeal exudates, bronchoalveolar lavage, tracheal aspirations, cerebrospinal fluid, semen, cervical mucus, vaginal or urethral secretions, amniotic fluid, and the like. Herein, fluid homogenates of cellular tissues such as, for example, hair, skin and nail scrapings, meat extracts and skins of fruits and nuts are also considered biological fluids. Pretreatment may involve preparing plasma from blood, diluting viscous fluids, and the like. Methods of treatment can involve filtration, distillation, separation, concentration, inactivation of interfering components, and the addition of reagents. Besides physiological fluids, other samples can be used such as water, food products, soil extracts, and the like for the performance of industrial, environmental, or food production assays as well as diagnostic assays. In addition, a solid material suspected of containing the analyte can be used as the test sample once it is modified to form a liquid medium or to release the analyte. The selection and pretreatment of biological, industrial, and environmental samples prior to testing is well known in the art and need not be described further.
[0031] As used herein, the term “specifically binds” refers to the binding specificity of a specific binding pair. “Specific pair binding member” refers to a member of a specific binding pair, i.e., two different molecules wherein one of the molecules specifically binds with the second molecule through chemical or physical means. The two molecules are related in the sense that their binding with each other is such that they are capable of distinguishing their binding partner from other assay constituents having similar characteristics. The members of the specific binding pair are referred to as ligand and receptor (antiligand), sbp member and sbp partner, and the like. A molecule may also be a sbp member for an aggregation of molecules; for example an antibody raised against an immune complex of a second antibody and its corresponding antigen may be considered to be an sbp member for the immune complex.
[0032] In addition to antigen and antibody specific binding pair members, other specific binding pairs include, as examples without limitation, biotin and avidin, carbohydrates and lectins, complementary nucleotide sequences, complementary peptide sequences, effector and receptor molecules, enzyme cofactors and enzymes, enzyme inhibitors and enzymes, a peptide sequence and an antibody specific for the sequence or the entire protein, polymeric acids and bases, dyes and protein binders, peptides and specific protein binders (e.g., ribonuclease, S-peptide and ribonuclease S-protein), metals and their chelators, and the like. Furthermore, specific binding pairs can include members that are analogs of the original specific binding member, for example an analyte-analog or a specific binding member made by recombinant techniques or molecular engineering.
[0033] An sbp member is analogous to another sbp member if they are both capable of binding to another identical complementary sbp member. Such an sbp member may, for example, be either a ligand or a receptor that has been modified by the replacement of at least one hydrogen atom by a group to provide, for example, a labeled ligand or labeled receptor. The sbp members can be analogous to or complementary to the analyte or to an sbp member that is complementary to the analyte.
[0034] If the specific binding member is an immunoreactant it can be, for example, an antibody, antigen, hapten, or complex thereof. If an antibody is used, it can be a monoclonal or polyclonal antibody, a recombinant protein or antibody, a chimeric antibody, a mixture(s) or fragment(s) thereof, as well as a mixture of an antibody and other specific binding members. The details of the preparation of such antibodies and their suitability for use as specific binding members are known to those skilled in the art.
[0035] “Antigen” shall mean any compound capable of binding to an antibody, or against which antibodies can be raised.
[0036] “Antibody” refers to a polypeptide substantially encoded by an immunoglobulin gene or immunoglobulin genes, or fragments thereof. The recognized immunoglobulin genes include the kappa, lambda, alpha, gamma, delta, epsilon, and mu constant regions, as well as myriad immunoglobulin variable region genes. Light chains are classified as either kappa or lambda. Heavy chains are classified as gamma, mu, alpha, delta, or epsilon, which in turn define the immunoglobulin classes, IgG, IgM, IgA, IgD, and IgE, respectively. Typically, an antibody is an immunoglobulin having an area on its surface or in a cavity that specifically binds to and is thereby defined as complementary with a particular spatial and polar organization of another molecule. The antibody can be polyclonal or monoclonal. Antibodies may include a complete immunoglobulin or fragments thereof. Fragments thereof may include Fab, Fv and F(ab′)2, Fab′, and the like. Antibodies may also include chimeric antibodies or fragment thereof made by recombinant methods.
[0037] “Analyte” refers to the compound or composition to be detected or measured and which has at least one epitope or binding site. The analyte can be any substance for which there exists a naturally occurring analyte specific binding member or for which an analyte-specific binding member can be prepared. e.g., carbohydrate and lectin, hormone and receptor, complementary nucleic acids, and the like. Further, possible analytes include virtually any compound, composition, aggregation, or other substance which may be immunologically detected. That is, the analyte, or portion thereof, will be antigenic or haptenic having at least one determinant site, or will be a member of a naturally occurring binding pair.
[0038] Analytes include, but are not limited to, toxins, organic compounds, proteins, peptides, microorganisms, bacteria, viruses, amino acids, nucleic acids, carbohydrates, hormones, steroids, vitamins, drugs (including those administered for therapeutic purposes as well as those administered for illicit purposes), pollutants, pesticides, and metabolites of or antibodies to any of the above substances. The term analyte also includes any antigenic substances, haptens, antibodies, macromolecules, and combinations thereof. A non-exhaustive list of exemplary analytes is set forth in U.S. Pat. No. 4,366,241, at column 19, line 7 through column 26, line 42, the disclosure of which is incorporated herein by reference. Further descriptions and listings of representative analytes are found in U.S. Pat. Nos. 4,299,916; 4,275,149; and 4,806,311, all incorporated herein by reference.
[0039] “Labeled reagent” refers to a substance comprising a detectable label attached with a specific binding member. The attachment may be covalent or non-covalent binding, but the method of attachment is not critical to the present invention. The label allows the label reagent to produce a detectable signal that is related to the presence of analyte in the fluid sample. The specific binding member component of the label reagent is selected to directly bind to the analyte or to indirectly bind the analyte by means of an ancillary specific binding member, which is described in greater detail hereinafter. The label reagent can be incorporated into the test device at a site upstream from the capture zone, it can be combined with the fluid sample to form a fluid solution, it can be added to the test device separately from the test sample, or it can be predeposited or reversibly immobilized at the capture zone. In addition, the specific binding member may be labeled before or during the performance of the assay by means of a suitable attachment method.
[0040] “Label” refers to any substance which is capable of producing a signal that is detectable by visual or instrumental means. Various labels suitable for use in the present invention include labels which produce signals through either chemical or physical means. Such labels can include enzymes and substrates, chromogens, catalysts, fluorescent compounds, chemiluminescent compounds, and radioactive labels. Other suitable labels include particulate labels such as colloidal metallic particles such as gold, colloidal non-metallic particles such as selenium or tellurium, dyed or colored particles such as a dyed plastic or a stained microorganism, organic polymer latex particles and liposomes, colored beads, polymer microcapsules, sacs, erythrocytes, erythrocyte ghosts, or other vesicles containing directly visible substances, and the like. Typically, a visually detectable label is used as the label component of the label reagent, thereby providing for the direct visual or instrumental readout of the presence or amount of the analyte in the test sample without the need for additional signal producing components at the detection sites.
[0041] The selection of a particular label is not critical to the present invention, but the label will be capable of generating a detectable signal either by itself, or be instrumentally detectable, or be detectable in conjunction with one or more additional signal producing components, such as an enzyme/substrate signal producing system. A variety of different label reagents can be formed by varying either the label or the specific binding member component of the label reagent; it will be appreciated by one skilled in the art that the choice involves consideration of the analyte to be detected and the desired means of detection. As discussed below, a label may also be incorporated used in a control system for the assay.
[0042] For example, one or more signal producing components can be reacted with the label to generate a detectable signal. If the label is an enzyme, then amplification of the detectable signal is obtained by reacting the enzyme with one or more substrates or additional enzymes and substrates to produce a detectable reaction product.
[0043] In an alternative signal producing system, the label can be a fluorescent compound where no enzymatic manipulation of the label is required to produce the detectable signal. Fluorescent molecules include, for example, fluorescein, phycobiliprotein, rhodamine and their derivatives and analogs are suitable for use as labels in such a system.
[0044] The use of dyes for staining biological materials, such as proteins, carbohydrates, nucleic acids, and whole organisms is documented in the literature. It is known that certain dyes stain particular materials preferentially based on compatible chemistries of dye and ligand. For example, Coomassie Blue and Methylene Blue for proteins, periodic acid-Schiff s reagent for carbohydrates, Crystal Violet, Safranin O, and Trypan Blue for whole cell stains, ethidium bromide and Acridine Orange for nucleic acid staining, and fluorescent stains such as rhodamine and Calcofluor White for detection by fluorescent microscopy. Further examples of labels can be found in, at least, U.S. Pat. Nos. 4,695,554; 4,863,875; 4,373,932; and 4,366,241, all incorporated herein by reference.
[0045] “Signal producing component” refers to any substance capable of reacting with another assay reagent or with the analyte to produce a reaction product or signal that indicates the presence of the analyte and that is detectable by visual or instrumental means. “Signal production system”, as used herein, refers to the group of assay reagents that are needed to produce the desired reaction product or signal.
[0046] “Observable signal” as used herein refers to a signal produced in the claimed devices and methods that is detectable by visual inspection. Without limitation, the type of signal produced depends on the label reagents and marks used (described herein). Generally, observable signals indicating the presence or absence of an analyte in a sample may be evident of their own accord, e.g., plus or minus signs or particularly shaped symbols, or may be evident through the comparison with a panel such as a color indicator panel.
[0047] “Axial flow” as used herein refers to lateral, vertical or transverse flow through a particular matrix or material comprising one or more test and/or control zones. The type of flow contemplated in a particular device, assay or method varies according to the structure of the device. Without being bound by theory, lateral, vertical or transverse flow may refer to flow of a fluid sample from the point of fluid contact on one end or side of a particular matrix (the upstream or proximal end) to an area downstream (or distal) of this contact. The downstream area may be on the same side or on the opposite side of the matrix from the point of fluid contact. For example, in vertical flow devices of the present invention, axial flow may progress vertically from and through a first member (top to bottom) to a second member and from there on to an absorbent medium. By way of further example, and as will be appreciated by those of skill in the art, in a vertical flow device configured, for example, as a dipstick, a fluid sample may flow literally up the device, in which case however, the point of first contact of the fluid sample to the device is nonetheless considered the upstream (i.e., proximal) end and the point of termination of flow the downstream (i.e., distal) end.
[0048] “Absorbent material” as used herein refers to material used in vertical flow devices and assays that allows and promotes sample flow through the first and second members. Such materials may be as described in, e.g., U.S. Pat. No. 4,632,901, such as, for example, fibrous materials such as cellulose acetate fibers, cellulose or cellulose derivatives, polyester, or polyolefin. Generally, the absorbent material, as used herein, should maintain direct or intimate contact with the second member in order to promote fluid flow therethrough. Contemplated absorbent materials having fluid absorptive qualities are generally compressible and may be compressed in devices of the present invention to ensure contact with the second member or positive control element.
[0049] As used herein the phrase “mark that is detectable within the test region when the test region is in a moist state” refers to the type of mark described, for example in U.S. patent application Ser. No. 09/950,366, filed, Sep. 10, 2001, currently pending and published as U.S. Patent Application Publication No. 20030049167, and 10/241,822, filed Sep. 10, 2002, currently pending and published as U.S. Patent Application Publication No. 20030157699.
[0050] As used herein the terms “upstream” and “downstream” refer to the direction of fluid sample flow subsequent to contact of the fluid sample with a representative device of the present disclosure, wherein, under normal operating conditions, the fluid sample flow direction runs from an upstream position to a downstream position. For example, when fluid sample is initially contacted with the sample receiving zone, the fluid sample then flows downstream through the label zone and so forth.
[0051] As used herein the phrase “completion of an assay” refers to axial flow of applied liquid sample suspected of containing one or more analytes through a representative device, downstream of at least one test zone and at least one control zone. Thus, as used herein multiple assays could be completed in a single device which comprises multiple pairs of alternating test and control zones. More commonly, the phrase completion of assay refers to axial flow of applied liquid sample suspected of containing one or more analytes through a representative device, downstream of all test and control zones on or in the device.
B. TEST DEVICES
[0052] The present description provides for the development and use of single or multiple control zones in a single immunoassay device that are positioned in a predetermined manner relative to individual test zones thereby allowing easy identification of each of the one or more analytes of interest tested for in the device. The present description further provides for the making of control zones of various shapes, physical or chemical identities, and colors. In part, the use of such control zones allows for immunoassay devices, particularly including dipsticks, that are easy to use, and allow for the identification of multiple analytes during a single assay procedure.
[0053] The present description further provides means to build a rapid, multi-analyte assay, which is needed in many fields of environmental monitoring, medicine, particularly in the field of infectious disease. For example, contemplated devices include those useful for the differential diagnosis of Flu A or Flu B, which may result in different treatments, or the differential diagnosis of Flu A. Flu B, and/or RSV in one step. Such devices permit the use of a single sample for assaying multiple analytes at once, and beneficially allows for a considerable reduction of the hands-on time and duration of the diagnostic process for the benefit of the doctor, or user in general.
[0054] A variety of analytes may be assayed utilizing devices and methods of the present disclosure. In a particular device useful for assaying for one or more analytes of interest in a sample, the collection of analytes of interest may be referred to as a panel. For example, a panel may comprise any combination (or all of) of influenza A, influenza B, respiratory syncytial virus (RSV), adenovirus, and parainfluenza virus. Another panel may comprise testing for a selection of one or more of upper respiratory infection including, for example, streptococcus pneumoniae, mycoplasma and/or pneumoniae. Yet another panel can be devised for the diagnosis of sexually transmitted disease including, for example, Chlamydia, Trichomonas and/or Gonorrhea.
[0055] On occasion a panel may optionally include a variety of other analytes of interest, including SARS-associated coronavirus, influenza C; a hepatitis panel comprising a selection of hepatitis B surface Ag or Ab, hepatitis B core Ab, hepatitis A virus Ab, and hepatitis C virus; a phospholipids panel comprising a selection of Anticardiolipin Abs (IgG, IgA, and IgM Isotypes); an arthritis panel comprising a selection of rheumatoid factor, antinuclear antibodies, and Uric Acid; an Epstein Barr panel comprising a selection of Epstein Barr Nuclear Ag, Epstein Barr Viral Capsid Ag, and Epstein Barr Virus, Early Antigen; other panels include HIV panels, Lupus panels, H. Pylori panels, toxoplasma panels, herpes panels, Borrelia panels, rubella panels, cytomegalovirus panels, and many others. One of skill in art would understand that a variety of panels may be assayed via the immunoassays described herein. See, e.g., C URRENT P ROTOCOLS IN I MMUNOLOGY (Coligan, John E. et. al., eds. 1999).
[0056] Other fields of interest include the diagnosis of veterinary diseases, analysis of meat, poultry, fish for bacterial contamination, inspection of food plants, restaurants, hospitals and other public facilities, analysis of environmental samples including water for beach, lakes or swimming pool contamination. Analytes detected by these tests include viral and bacterial antigens as well as chemicals including, for example, lead, pesticides, hormones, drugs and their metabolites, hydrocarbons and all kinds of organic or inorganic compounds.
[0057] The present disclosure provides a test device, particularly immunoassay devices, for determining the presence or absence of multiple analytes in a fluid sample. In general, a test device of the present disclosure includes a matrix defining an axial flow path. Typically, the matrix further includes a sample receiving zone, a label zone, a test zone and a control zone. In frequent embodiments, a test region comprises the test and control zones. In a related embodiment, the matrix further includes an absorbent zone disposed downstream of the test region. Moreover, in preferred embodiments, the test region, which comprises the test and control zones, is observable.
[0058] Numerous analytical devices known to those of skill in the art may be adapted in accordance with the present invention, to detect multiple analytes. By way of example, dipstick, lateral flow and flow-through devices, particularly those that are immunoassays, may be modified in accordance herewith in order to detect and distinguish multiple analytes. Exemplary lateral flow devices include those described in U.S. Pat. Nos. 4,818,677, 4,943,522, 5,096,837 (RE 35,306), 5,096,837, 5,118,428, 5,118,630, 5,221,616, 5,223,220, 5,225,328, 5,415,994, 5,434,057, 5,521,102, 5,536,646, 5,541,069, 5,686,315, 5,763,262, 5,766,961, 5,770,460, 5,773,234, 5,786,220, 5,804,452, 5,814,455, 5,939,331, 6,306,642. Other lateral flow devices that may be modified for use in distinguishable detection of multiple analytes in a fluid sample include U.S. Pat. Nos. 4,703,017, 6,187,598, 6,352,862, 6,485,982, 6,534,320 and 6,767,714. Exemplary dipstick devices include those described in U.S. Pat. Nos. 4,235,601, 5,559,041, 5,712,172 and 6,790,611. It will be appreciated by those of skill in the art that the aforementioned patents may and frequently do disclose more than one assay configuration and are likewise referred to herein for such additional disclosures. Advantageously, the improvements described are applicable to various assay, especially immunoassay, configurations.
[0059] In a frequent embodiment, the sample receiving zone accepts a fluid sample that may contain analytes of interest. In another embodiment, the sample receiving zone is dipped into a fluid sample. A label zone is located downstream of the sample receiving zone, and contains one or more mobile label reagents that recognize, or are capable of binding the analytes of interest. Further, a test region is disposed downstream from the label zone, and contains test and control zones. The test zone(s) generally contain means which permit the restraint of a particular analyte of interest in each test zone. Frequently, the means included in the test zone(s) comprise an immobilized capture reagent that binds to the analyte of interest. Generally the immobilized capture reagent specifically binds to the analyte of interest. Although, on occasion, the means which permit the restraint of a particular analyte of interest in each test zone comprise another physical, chemical or immunological means for specifically restraining an analyte of interest. Thus, as the fluid sample flows along the matrix, the analyte of interest will first bind with a mobilizable label reagent in the label zone, and then become restrained in the test zone. In occasional embodiments, the test region is comprised of a material that is opaque in a dry state and transparent in a moist state. Thus, when a control zone comprising a mark on the device is utilized, this mark is positioned about the test region such that it becomes visible within the test region when the test region is in a moist state.
[0060] In another preferred embodiment, the fluid sample flows along a flow path running from the sample receiving zone (upstream), through the label zone, and then to the test and control zones (together comprised in a test region) (downstream). Optionally, the fluid sample may thereafter continue to the absorbent zone.
[0061] In one embodiment, the sample receiving zone is comprised of an absorbent application pad. Suitable materials for manufacturing absorbent application pads include, but are not limited to, hydrophilic polyethylene materials or pads, acrylic fiber, glass fiber, filter paper or pads, desiccated paper, paper pulp, fabric, and the like. For example, the sample receiving zone may be comprised of a material such as a nonwoven spunlaced acrylic fiber, i.e., New Merge (available from DuPont) or HDK material (available from HDK Industries, Inc.). In a related embodiment, the sample receiving zone is constructed from any material that is capable of absorbing water.
[0062] In another embodiment, the sample receiving zone is comprised of any material from which the fluid sample can pass to the label zone. Further, the absorbent application pad can be constructed to act as a filter for cellular components, hormones, particulate, and other certain substances that may occur in the fluid sample. Application pad materials suitable for use by the present invention also include those application pad materials disclosed in U.S. Pat. No. 5,075,078, incorporated herein by reference.
[0063] The functions of the sample receiving zone may include, for example: pH control/modification and/or specific gravity control/modification of the sample applied, removal or alteration of components of the sample which may interfere or cause non-specific binding in the assay, or to direct and control sample flow to the test region. The filtering aspect allows an analyte of interest to migrate through the device in a controlled fashion with few, if any, interfering substances. The filtering aspect, if present, often provides for a test having a higher probability of success and accuracy. In another embodiment, the sample receiving zone may also incorporate reagents useful to avoid cross-reactivity with non-target analytes that may exist in a sample and/or to condition the sample; depending on the particular embodiment, these reagents may include non-hCG blockers, anti-RBC reagents, Tris-based buffers, EDTA, among others. When the use of whole blood is contemplated, anti-RBC reagents are frequently utilized. In yet another embodiment, the sample receiving zone may incorporate other reagents such as ancillary specific binding members, fluid sample pretreatment reagents, and signal producing reagents.
[0064] In a further embodiment, the sample receiving zone is comprised of an additional sample application member (e.g., a wick). Thus, in one aspect, the sample receiving zone can comprise a sample application pad as well as a sample application member. Often the sample application member is comprised of a material that readily absorbs any of a variety of fluid samples contemplated herein, and remains robust in physical form. Frequently, the sample application member is comprised of a material such as white bonded polyester fiber. Moreover, the sample application member, if present, is positioned in fluid-flow contact with a sample application pad. This fluid flow contact can comprise an overlapping, abutting or interlaced type of contact. In occasional embodiments, the sample application member may be treated with a hydrophilic finishing. Often the sample application member, if present, may contain similar reagents and be comprised of similar materials to those utilized in exemplary sample application pads.
[0065] In another embodiment, the test device is configured to perform an immunological analysis process. In yet another embodiment, the liquid transport along the matrix is based upon capillary action. In a further embodiment, the liquid transport along the matrix is based on non-bibulous lateral flow, wherein all of the dissolved or dispersed components of the liquid sample are carried at substantially equal rates and with relatively unimpaired flow laterally through the matrix, as opposed to preferential retention of one or more components as would occur, e.g., in materials that interact, chemically, physically, ionically or otherwise with one or more components. See for example, U.S. Pat. No. 4,943,522, hereby incorporated by reference in its entirety.
[0066] One purpose of the label zone is to maintain label reagents and control reagents in a stable state and to facilitate their rapid and effective solubilization, mobilization and specific reaction with analytes of interest potentially present in a fluid sample.
[0067] In one embodiment, the label zone is comprised of a porous material such as high density polyethylene sheet material manufactured by Porex Technologies Corp. of Fairburn, Ga., USA. The sheet material has an open pore structure with a typical density, at 40% void volume, of 0.57 gm/cc and an average pore diameter of 1 to 250 micrometers, the average generally being from 3 to 100 micrometers. In another embodiment, the label zone is comprised of a porous material such as a nonwoven spunlaced acrylic fiber (similar to the sample receiving zone), e.g., New Merge or HDK material. Often, the porous material may be backed by, or laminated upon, a generally water impervious layer, e.g., Mylar. When employed, the backing is generally fastened to the matrix by an adhesive (e.g., 3M 444 double-sided adhesive tape). Typically, a water impervious backing is used for membranes of low thickness. A wide variety of polymers may be used provided that they do not bind nonspecifically to the assay components and do not interfere with flow of the fluid sample. Illustrative polymers include polyethylene, polypropylene, polystyrene and the like. On occasion, the matrix may be self-supporting. Other membranes amenable to non-bibulous flow, such as polyvinyl chloride, polyvinyl acetate, copolymers of vinyl acetate and vinyl chloride, polyamide, polycarbonate, polystyrene, and the like, can also be used. In yet another embodiment, the label zone is comprised of a material such as untreated paper, cellulose blends, nitrocellulose, polyester, an acrylonitrile copolymer, and the like. The label zone may be constructed to provide either bibulous or non-bibulous flow, frequently the flow type is similar or identical to that provided in at least a portion of the sample receiving zone. In a frequent embodiment, the label zone is comprised of a nonwoven fabric such as Rayon or glass fiber. Other label zone materials suitable for use by the present invention include those chromatographic materials disclosed in U.S. Pat. No. 5,075,078, which is herein incorporated by reference.
[0068] In a frequent embodiment, the label zone material is treated with labeled solution that includes material-blocking and label-stabilizing agents. Blocking agents include bovine serum albumin (BSA), methylated BSA, casein, nonfat dry milk. Stabilizing agents are readily available and well known in the art, and may be used, for example, to stabilize labeled reagents. In frequent embodiments, employment of the selected blocking and stabilizing agents together with labeled reagent in the labeling zone followed by the drying of the blocking and stabilizing agents (e.g., a freeze-drying or forced air heat drying process) is utilized to attain improved performance of the device.
[0069] The label zone generally contains a labeled reagent, often comprising one or more labeled reagents. In many of the presently contemplated embodiments, multiple types of labeled reagents are incorporated in the label zone such that they may permeate together with a fluid sample contacted with the device. These multiple types of labeled reagent can be analyte specific or control reagents and may have different detectable characteristics (e.g., different colors) such that one labeled reagent can be differentiated from another labeled reagent if utilized in the same device. As the labeled reagents are frequently bound to a specific analyte of interest subsequent to fluid sample flow through the label zone, differential detection of labeled reagents having different specificities (including analyte specific and control labeled reagents) may be a desirable attribute. However, frequently, the ability to differentially detect the labeled reagents having different specificities based on the label component alone is not necessary due to the presence of defined test and control zones in the device, which allow for the accumulation of labeled reagent in designated zones.
[0070] In one embodiment, a nonparticulate labeling scheme is contemplated. In these devices, a label which is a dyed antibody-enzyme complex is utilized. This dyed antibody-enzyme complex can be prepared by polymerizing an antibody-enzyme conjugate in the presence of enzyme substrate and surfactant. See, e.g., WO 9401775. Generally, the label zone contains detectible moieties comprising enzyme-antibody conjugate, particulate labeled reagents, or dye labeled reagents, metal sol labeled reagents, etc., or moieties which may or may not be visible, but which can be detected if accumulated in the test and/or control zones. The detectible moieties can be dyes or dyed polymers which are visible when present in sufficient quantity, or can be, and are preferred to be particles such as dyed or colored latex beads, liposomes, metallic or non-metallic colloids, organic, inorganic or dye solutions, dyed or colored cells or organisms, red blood cells and the like. The detectible moieties used in the assay provide the means for detection of the nature of and/or quantity of result, and accordingly, their localization in the test zones may be a function of the analyte in the sample. In general, this can be accomplished by coupling the detectible moieties to a ligand which binds specifically to an analyte of interest, or which competes with an analyte of interest for the means which permit the restraint of an analyte of interest positioned in the test zone(s). In the first approach, the detectible moieties are coupled to a specific binding partner which binds the analyte specifically. For example, if the analyte is an antigen, an antibody specific for this antigen may be used; immunologically reactive fragments of the antibody, such as F(ab′)2, Fab or Fab′ can also be used. These ligands coupled to the detectible moieties then bind to an analyte of interest if present in the sample as the sample passes through the labeling zone and are carried into the test region by the fluid flow through the device. When the labeled analyte reaches the capture zone, it is restrained by a restraint reagent which is analyte-specific, label/detectible moiety-specific, or ligand-specific, such as an antibody or another member of a specific binding pair. In the second approach, the conjugate or particulate moieties are coupled to a ligand which is competitive with analyte for an analyte-specific restraint reagent in a test zone. Both the analyte from the sample and the competitor bound to the detectible moieties progress with the flow of the fluid sample to the test region. Both analyte and its competitor then react with the analyte-specific restraint reagent positioned in a test zone. The unlabeled analyte thus is able to reduce the quantity of competitor-conjugated detectible moieties which are retained in the test zone. This reduction in retention of the detectible moieties becomes a measure of the analyte in the sample.
[0071] The labeling zone of immunoassay devices of the present invention may also include control-type reagents. These labeled control reagents often comprise detectible moieties that will not become restrained in the test zones and that are carried through to the test region and control zone(s) by fluid sample flow through the device. In a frequent embodiment, these detectible moieties are coupled to a member of a specific binding pair to form a control conjugate which can than be restrained in a separate control zone of the test region by a corresponding member of the specific binding pair to verify that the flow of liquid is as expected. The visible moieties used in the labeled control reagents may be the same or different color, or of the same or different type, as those used in the analyte of interest specific labeled reagents. If different colors are used, ease of observing the results may be enhanced. Generally, as used herein, the labeled control reagents are also referred to herein together with analyte specific labeled reagents or labeled test reagents as “labeled reagent(s).”
[0072] The test region is frequently comprised of a material such as cellulose, nitrocellulose, nylon, or hydrophilic polyvinylidene difluoride (PVDF). Hydrophilic polyvinylidene difluoride (PVDF) (available from Millipore, Billerica, Mass.). The term “nitrocellulose” is meant any nitric acid ester of cellulose. Thus suitable materials may include nitrocellulose in combination with carboxylic acid esters of cellulose. The pore size of nitrocellulose membranes may vary widely, but is frequently within about 5 to 20 microns, preferably about 8 to 15 microns. However, other materials are contemplated which are known to those skilled in the art. In a frequent embodiment, the test region comprises a nitrocellulose web assembly made of Millipore nitrocellulose roll laminated to a clear Mylar backing. In another embodiment, the test region is made of nylon. In less occasional embodiment, the test region is comprised of a material that can immobilize latex or other particles which carry a second reagent capable of binding specifically to an analyte, thereby defining a test zone, for example, compressed nylon powder, or fiber glass. In an occasional embodiment, the test region is comprised of a material that is opaque when in a dry state, and transparent when in a moistened state. Preferably, the test and control zones may be constructed from any of the materials as listed above for the test region. Often the test and control zones form defined components of the test region. In a particularly preferred embodiment, the test and control zones are comprised of the same material as the test region. Frequently, the term “test region” is utilized herein to refer to a region in/on a device that comprises at least the test and control zones. To provide non-bibulous flow, these materials may be and preferably are treated with blocking agents that can block the forces which account for the bibulous nature of bibulous membranes. Suitable blocking agents include bovine serum albumin, methylated bovine serum albumin, whole animal serum, casein, and non-fat dry milk, as well as a number of detergents and polymers, e.g., PEG, PVA and the like. Preferably the interfering sites on the untreated bibulous membranes are completely blocked with the blocking agent to permit non-bibulous flow there through. As indicated herein, the present disclosure envisages a test device with multiple test and control zones.
[0073] The test region generally includes a control zone that is useful to verify that the sample flow is as expected. Each of the control zones comprise a spatially distinct region that often includes an immobilized member of a specific binding pair which reacts with a labeled control reagent. In an occasional embodiment, the procedural control zone contains an authentic sample of the analyte of interest, or a fragment thereof. In this embodiment, one type of labeled reagent can be utilized, wherein fluid sample transports the labeled reagent to the test and control zones; and the labeled reagent not bound to an analyte of interest will then bind to the authentic sample of the analyte of interest positioned in the control zone. In another embodiment, the control line contains antibody that is specific for, or otherwise provides for the immobilization of, the labeled reagent. In operation, a labeled reagent is restrained in each of the one or more control zones, even when any or all the analytes of interest are absent from the test sample.
[0074] In a less occasional embodiment, a labeled control reagent is introduced into the fluid sample flow, upstream from the control zone. For example, the labeled control reagent may be added to the fluid sample before the sample is applied to the assay device. In frequent embodiments, the labeled control reagent may be diffusively bound in the sample receiving zone, but is preferably diffusively bound in the label zone.
[0075] Exemplary functions of the labeled control reagents and zones include, for example, the confirmation that the liquid flow of the sample effectively solubilized and mobilized the labeled reagents deposited in the label zone, that a sufficient amount of liquid traveled correctly through the sample receiving zone, label zone, and the test and control zones, such that a sufficient amount of analyte could react with the corresponding specific label in the label zone, migrate onto the test region comprising the test and control zones, cross the test zone(s) in an amount such that the accumulation of the labeled analyte would produce a visible or otherwise readable signal in the case of a positive test result in the test zone(s). Moreover, an additional function of the control zones may be to act as reference zones which allow the user to identify the test results which are displayed as readable zones.
[0076] Since the devices of the present invention may incorporate one or more control zones, the labeled control reagent and their corresponding control zones are preferably developed such that each control zone will become visible with a desired intensity for all control zones after fluid sample is contacted with the device, regardless of the presence or absence of one or more analytes of interest.
[0077] In one embodiment, a single labeled control reagent will be captured by each of the control zones on the test strip. Frequently, such a labeled control reagent will be deposited onto or in the label zone in an amount exceeding the capacity of the total binding capacity of the combined control zones if multiple control zones are present. Accordingly, the amount of capture reagent specific for the control label can be deposited in an amount that allows for the generation of desired signal intensity in the one or more control zones, and allows each of the control zones to restrain a desired amount of labeled control reagent. At the completion of an assay, each of the control zones preferably provide a desired and/or pre-designed signal (in intensity and form). Examples of contemplated pre-designed signals include signals of equal intensities in each control zone, or following a desired pattern of increasing, decreasing or other signal intensity in the control zones.
[0078] In another embodiment, each control zone will be specific for a unique control reagent. In this embodiment, the label zone may include multiple and different labeled control reagents, equaling the number of control zones in the assay, or a related variation. Wherein each of the labeled control reagents may become restrained in one or more pre-determined and specific control zone(s). These labeled control reagents can provide the same detectible signal (e.g., be of the same color) or provide distinguishable detectible signals (e.g., have different colored labels or other detection systems) upon accumulation in the control zone(s).
[0079] In yet another embodiment, the control zones may include a combination of the two types of control zones described in the two previous embodiments, specifically, one or more control zones are able to restrain or bind a single type of labeled control reagent, and other control zones on the same test strip will be capable of binding one or several other specific labeled control reagents.
[0080] In one embodiment, the labeled control reagent comprises a detectible moiety coupled to a member of a specific binding pair. Typically, a labeled control reagent is chosen to be different from the reagent that is recognized by the means which are capable of restraining an analyte of interest in the test zone. Further, the labeled control reagent is generally not specific for the analyte. In a frequent embodiment, the labeled control reagent is capable of binding the corresponding member of a specific binding pair or control capture partner that is immobilized on or in the control zone. Thus the labeled control reagent is directly restrained in the control zone.
[0081] In another embodiment, the detectable moiety which forms the label component of the labeled control reagent is the same detectible moiety as that which is utilized as the label component of the analyte of interest labeled test reagent. In a frequent embodiment, the label component of the labeled control reagent is different from the label component of the labeled test reagent, so that results of the assay are easily determined. In another frequent embodiment, the control label and the test label include colored beads, e.g., colored latex. Also frequently, the control and test latex beads comprise different colors.
[0082] In a further embodiment, the labeled control reagent includes streptavidin, avidin or biotin and the control capture partner includes the corresponding member of such specific binding pairs, which readily and specifically bind with one another. In one example, the labeled control reagent includes biotin, and the control capture partner includes streptavidin. The artisan will appreciate that other members of specific binding pairs can alternatively be used, including, for example, antigen/antibody reactions unrelated to analyte.
[0083] The use of a control zone is helpful in that appearance of a signal in the control zone indicates the time at which the test result can be read, even for a negative result. Thus, when the expected signal appears in the control line, the presence or absence of a signal in a test zone can be noted.
[0084] In still further embodiment, a control zone comprising a mark that becomes visible in the test region when the test regions is in a moist state is utilized. Control zones of this type are described in U.S. patent application Ser. No. 09/950,366, filed, Sep. 10, 2001, currently pending and published as U.S. Patent Application Publication No. 20030049167, and 10/241,822, filed Sep. 10, 2002, currently pending and published as U.S. Patent Application Publication No. 20030157699.
[0085] In occasional embodiments, one or more control zones of this type are utilized. In another embodiment, a combination of control zones of the type utilizing labeled control reagents and control zone and of the type that display the control zone when in a moist state can be used. This allows a simple way to formulate control zones while allowing to use a reagent-based control zone to ascertain that the re-solubilization and mobilization of the reagents in the label pad process has been effective, and that the specific reactions took place as expected, all along the path defined by the sample pad, label pad, test strip and absorbent pad. The present embodiment includes the use of one or more control zones that become visible when the test region is in the moist state for each of the control zones of an assay, except the control zone on the distal or downstream end of the test strip.
[0086] As indicated above, labeled test reagents are further provided which frequently comprise a test label coupled to a member of a specific binding pair that is capable of specifically binding an analyte of interest. Thus, in general, multiple labeled test reagents are positioned in the label zone, each of which is specific for a predetermined analyte of interest.
[0087] Test zones of the present description include means that permit the restraint of an analyte of interest. Frequently, test zones of the present description include a ligand that is capable of specifically binding to an analyte of interest. Alternatively, test zones of the present description include a ligand that is capable of specifically binding the labeled reagent bound to an analyte of interest. In practice, a labeled test reagent binds an analyte of interest present in a fluid sample after contact of the sample with a representative device and flow of the fluid sample into and through the label zone. Thereafter, the fluid sample containing the labeled analyte progresses to a test zone and becomes restrained in the test zone. The accumulation of labeled analyte in the test zone produces a detectible signal. Frequently, devices of the present disclosure incorporate one or more test zones, each of which is capable of restraining different analytes, if present, in a fluid sample. Thus, in representative embodiments two, three, four, five or more (labeled) analytes of interest can be restrained in a single or different test zones, and thereby detected, in a single device.
[0088] The present devices may optionally further comprise an absorbent zone that acts to absorb excess sample after the sample migrates through the test region. The absorbent zone, when present lies in fluid flow contact with the test region. This fluid flow contact can comprise an overlapping, abutting or interlaced type of contact. In an occasional embodiment, a control region (end of assay indicator) is provided in the absorbent zone to indicate when the assay is complete. In this embodiment, specialized reagents are utilized, such as pH sensitive reagents (such as bromocresol green), to indicate when the fluid sample has permeated past all of the test and control zones. Alternatively, the end of assay control region may be effected by applying a line of soluble ink on the test region after all of the test and control zones, and at the interface with the absorbent zone. In general, the liquid front moving through the capture zone will solubilize the ink and transfer it into the absorbent. The resulting color change will be seen in an observation window above the absorbent zone, signifying end of assay. Thus, these types of control regions are not specific for a particular analyte. Generally, the absorbent zone will consist of an absorbent material such as filter paper, a glass fiber filter, or the like.
[0089] In an occasional embodiment, the fluid sample must be processed or treated prior to contact with the device to ensure accurate detection of at least one of the multiple analytes of interest. In this embodiment, a reagent, such as an extraction solution, may be used to prepare the sample. Alternatively, reagents can be added to the test device after initial contact with the fluid sample. For example, the sample is introduced to the device, and thereafter a reagent, such as a developer solution, is added to complete the assay.
[0090] FIG. 1 provides various representative configurations of the presently contemplated devices. Although not specifically limited to dipstick type assays, these configurations may be incorporated in a dipstick-type assay among other types of immunoassay devices contemplated herein. The arrow in each Figure indicates the general direction of fluid sample flow after initial contact with the device. The boxes containing vertical lines and/or the diagonal lines depict control zones, and the boxes containing crosshatched lines depict test zones. The sample receiving zone [1], the label zone [2] and the test region [3] are also depicted. The present disclosure is not intended to be limited to the configurations depicted in FIG. 1(A-J) . These views are merely provided for illustrative purposes. For example, the test and control zones are not necessarily of the same shapes and sizes depicted in FIG. 1 . Further, the sample receiving zone, the label zone and test region are not necessarily presented to scale. FIG. 1A depicts a device having two test zones and a single control zone, wherein the control zone is situated between the test zones within the flow path. FIG. 1B depicts a device having three test zones and two control zones, wherein the control zones are situated between the test zones within the flow path. Further, in FIG. 1B , the second test zone is situated between the two control zones within the flow path. FIG. 1C depicts a device having four test zones and two control zones, wherein the control zones are situated between the test zones within the flow path. Further, in FIG. 1C , the second and third test zones are adjacent without a control zones between these zones. FIG. 1D depicts a device having two test zones and a single control zone, wherein the control zone is situated downstream of the test zones within the flow path. FIG. 1E depicts a device having two test zones and a single control zone, wherein the control zone is situated upstream of the test zones within the flow path. FIG. 1F depicts a device having four test zones and three control zones, wherein the control zones are situated between the test zones within the flow path in a alternating fashion. FIG. 1G depicts a device having five test zones and one control zone, wherein the control zone is situated between the second to last and last test zones within the flow path. Further, in FIG. 1G , the first through fourth test zones are adjacent to one another without having control zones between each test zone. FIG. 1H depicts a device having three test zones and one control zone, wherein the control zone is situated between the second and third test zones within the flow path. FIG. 1I depicts a device having four test zones and three control zones (wherein two control zones are comprised of the same labeled-control reagent and binding reagent specific pair (or alternatively, are comprised of motifs that become visible when the test zone is moist), but one control zone (as indicated by the diagonal lines) is comprised of one distinct pair of labeled control reagent and control zone binding reagent). FIG. 1J depicts a device having four test zones and three control zones (wherein one control zone is comprised of the same labeled-control reagent and binding reagent specific pair (or alternatively, are comprised of motifs that become visible when the test zone is moist), but two control zones (as indicated by the diagonal lines) are comprised of one distinct pair of labeled control reagent and control zone binding reagent). Frequently, when two types of control zones or pairs of control zones reagents are used, each control zone may be colored differently. Other device configurations within the scope of the present disclosure are contemplated. For example, although not depicted, the present disclosure contemplates a device having one test zone and one control zone, wherein multiple analytes can be detected within the test zone.
[0091] Those of skill in the art will recognize that a variety of direct and indirect assay formats may be employed in the present devices. In a frequent embodiment, a direct assay format is utilized. Direct assays are exemplified by those that detect the presence of an antigen in a sample, as well as those that detect the presence of an antibody in a sample.
[0092] As provided above, particular devices of the present invention include a support. The support in these devices provides a convenient platform for performance of the assay. However, the composition and shape of the support are not critical and may vary. Occasionally, the support may be comprised of a plastic or nylon material.
[0093] In frequent embodiment, the present devices are in the form of a dipstick. Generally, dipsticks of the present invention are functionally analogous to the lateral assays described herein excepting the method of contacting a fluid sample. In embodiments configured as a dipstick, the matrix and support will generally be located on one end of the dipstick. The configuration of such devices will allow the device to be dipped or contacted with a fluid sample with one end of a matrix i.e., the sample receiving zone. After contacting the fluid sample, the sample preferably migrates in an axial flow path through the matrix from the sample receiving zone to the label zones and test region. Alternatively, the devices of the present invention may be shaped so that samples may be applied to the device by means other than dipping, e.g., application of controlled amounts of sample by pipettes or the like.
[0094] The present invention is further described by the following examples. The examples are provided solely to illustrate the invention by reference to specific embodiments. These exemplifications, while illustrating certain specific aspects of the invention, do not portray the limitations or circumscribe the scope of the disclosed invention.
EXAMPLES
Exemplary Test Device for Distinguishing Influenza A from Influenza B
[0095] An immunoassay device for use in determining the presence of and distinguishing between multiple analytes was constructed in accordance with the present invention. In particular, an immunoassay dipstick capable of diagnosing influenza and distinguishing between influenza A and influenza B infection was prepared. Those of skill in the art are familiar with the general methods for preparation of immunoassay dipstick devices (see, e.g., U.S. Pat. No. 5,712,172) as well as other lateral flow immunoassays. The exemplary device described herein may likewise be so constructed.
[0096] The exemplary test device comprised a sample pad containing sample conditioning reagents, a label pad containing monoclonal antibody against Influenza A nucleoprotein covalently bound to red colored latex microparticles (Duke Scientific), a monoclonal antibody against Influenza B nucleoprotein covalently bound onto red colored latex microparticles, and an unrelated protein (in this example, biotinylated BSA) bound to blue latex microparticles (Duke Scientific). The device was assembled, in order, as a sample pad in fluid communication with a label pad in fluid communication with a test pad (observation zone) in fluid communication with an absorbent pad at the device end. The pads were laminated, using 3M adhesive, onto a Mylar backing, in sequence and in fluid communication to allow lateral flow from one pad to the next. A strip of plastic material, comprising a cutout (“window”) over the observation zone, was then laminated on top of the device leaving a portion of the sample pad exposed for sample application. This plastic cover served the purpose of securing the pads in place and in overlapping contact with one another, so that fluid communication was maintained there between. Additionally, the plastic material was selected to provide sufficient rigidity to the final device to allow convenient handling by the user and to isolate the areas of the dipstick that are moistened during the testing process.
[0097] The observation zone was made of a Highflow Plus nitrocellulose membrane from Millipore laminated onto a white Mylar backing. Test and control reagents were deposited, using standard techniques, onto the observation zone membrane in the form of 3 lines, each perpendicular to the flow of sample and in order upstream to downstream as follows: anti-Flu B monoclonal antibodies against a second epitope of the Influenza B nucleoprotein at a concentration of about 3 mg/ml in phosphate buffer was deposited as the a first test zone; at about 3 mm downstream of the first test zone, a control zone was formed by depositing streptavidin labeled BSA; and at about 3 mm downstream of the first control zone a second test zone was formed by depositing an antibody against a second epitope of the Influenza A nucleoprotein (again, at a concentration of about 3 mg/ml in phosphate buffer). Thus, the two test zones and one control zone were configured as illustrated in FIG. 1A .
[0098] Once the test and control reagents were deposited and dried onto the nitrocellulose membrane, the membrane was rendered non-bibulous by treatment with a blocking solution. As discussed above, non-bibulous flow allows the components of interest in the assay to move at substantially the same rate along the test strip without preferential retention of such components. This facilitates flow of a sufficient quantity of labeled material across the test and control zones, such that positioning of the control line upstream of the second test line does not interfere with the effectiveness or reliability of the control zone.
[0099] At the end of the test device, the observation zone is in fluid contact with a pad of absorbent material, in this example, made of absorbent cellulosic paper (Whatman).
[0100] As is common in the industry, the concentration of each component was optimized during development of the test to allow the assay to reach the required sensitivity while avoiding non-specific binding. For instance, the colored latex/anti-Influenza A antibody conjugate was diluted serially and deposited onto label pads that were dried, assembled into functional strips, and tested with liquid samples of the viral nucleoprotein at concentrations ranging from 7.5 ng/ml to 100 ng/ml. The lowest concentration of conjugate allowing detection of the 7.5 ng/ml solution of the nucleoprotein was selected as optimal. The optimal concentration of anti-Influenza B antibody/colored latex conjugate was similarly optimized. The optimum concentration of the control protein/colored latex conjugate was selected to provide a line clearly visible to the eye after normal incubation of the assay. To construct the final product, the optimized label (conjugate) solutions were mixed together then applied to and dried on the label pad using standard techniques.
[0101] The size/capacity of the absorbent pad was optimized to ensure that a sufficient amount of sample liquid would move through the test strip and across the two test and one control zones to product a visible, accurate signal when as little as 7.5 ng/ml of Influenza A and 7.5 ng/ml of Influenza B nucleoproteins were present in the sample.
Test of Exemplary Device
[0102] To confirm that positioning of a control zone upstream of a test zone would not compromise the accuracy of a device according to the present invention, two devices were created and compared to one another. Both devices were constructed as described above, except that each was constructed with only an Influenza A test zone (single analyte). In one device, the control zone was located upstream of the test zone and in the second device the control zone was located downstream of the test zone. A sample of Influenza A nucleoprotein at a relatively low concentration (sufficient to generate a visible signal of about 0.030 O.D. measured on an optical density scanner after a 10 minute incubation) was prepared and applied to each device. FIG. 2 shows the ratios between the O.D. values of the test zone and the control zone for different volumes of sample for each of the two devices. Increasing sample volumes were used, ranging from 25 uL up to 300 uL, facilitating identification of the minimum sample volume required to generate sufficient signal for the assay to meet design specifications. The graph in FIG. 2 clearly shows that the ratios of the signals generated by the test zone and control zone in the two devices are virtually identical regardless of the position of the test zone relative to the control zone.
[0103] The above examples are included for illustrative purposes only and are not intended to limit the scope of the invention. Many variations to those described above are possible. Since modifications and variations to the examples described above will be apparent to those of skill in this art, it is intended that this invention be limited only by the scope of the appended claims. Citation herein of publications or documents is not intended as an admission that any of the foregoing is pertinent prior art.
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The present invention relates generally to an assay for detecting and differentiating multiple analytes, if present, in a single fluid sample, including devices and methods therefore.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/197,294, filed Apr. 14, 2000, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a manually operated dispensing device for delivering ophthalmic solution to the surface of an eye in a desired spray pattern with an impact pressure on the eye that is comfortably tolerated by an individual.
[0003] Traditionally, eye wash with an ophthalmic solution such as an isotone (0.9%) solution of sodium chloride, have been performed by pouring a relatively large amount of solution into the eye. The solution is conventionally maintained in a flexible container, the sealing of which is broken when the solution is to be used. Thereafter, the flexible container is held above the contaminated eye and the container is squeezed to allow a flow of solution into the eye. Although the result most often is good, the eye being adequately rinsed, the method suffers from a number of drawbacks. The amount of solution which flows out of the flexible container when it is squeezed is undesirably high, resulting in a loss of solution and an undesirable wetting of clothes etc. In this regard an excess of solution used does not improve the rinsing of the eye. Also, a certain free space is required above the eyes of the individual to be treated, in order for the container to be held above the eyes. Moreover, each container can only be used once since, when the seal has been broken, the sterilization of the solution remaining in the container is destroyed.
[0004] In U.S. Pat. No. 5,152,435 there is shown a manually operated dispensing pump intended to provide a precise quantity of ophthalmic solution to the surface of an eye in a desired spray pattern with an impact pressure on the eye that is comfortably tolerable by an individual. By the pump, the solution is pumped from a nonpressurized container. Although the object of the pump as shown is to provide a desired diverging spray pattern with a low impact pressure, it has been found that the spray flow from a manually operated pump, operatively connected to a nonpressurized container, is difficult to control. The resulting spray flow depends too much on the person using the pump, which means that too weak a press or too hard a press on the actuator button will result in undesired flow properties, such as spray pattern, droplet size and impact pressure, in the flow which is produced. Moreover, when the pump has not been used for some time, the actuator button must be pressed down a number of times before solution has been transported through the pipe all the way up to the nozzle. This means that the delivery of solution takes some time, time which may be crucial for the recovery of the eye.
[0005] From SE 451 295 there is known another device for delivering ophthalmic solution to the surface of an eye. The device exhibits a container for the solution which container also contains a drive gas capsule. When the device is to be used, the capsule is penetrated and the drive gas is brought to expand inside a rubber pouch. By the expansion of the rubber pouch, the solution is brought to form a spray flow via a nozzle. The device has at least the drawbacks that it can only be used once, and that instructions are needed in order for the individual to understand how to use the device. It is easy to understand that an individual who has received chemical or physical contamination in the eyes, cannot read information on the device, which means that there is a risk of misuse of the device, leading to a fatal result for the eyes.
[0006] For other types of dispensing devices, such as nose sprays, shaving foam, cosmetic sprays, etc., it is known to use a “bag-in-can” concept in order to achieve a pressurized dispensing device without the use of halogenated compounds in the drive gas. The “bag-in-can” concept includes a pressure container having a closed bottom and an open top defining a neck, for accommodating a pressurized gas and a sealed, flexible pouch. The pouch, which accordingly is accommodated inside the container is made of an essentially diffusion proof barrier material and exhibits a valve which is integrated with a mounting cup adapted to fit the neck of the container. When the container is to be filled with liquid and drive gas, the drive gas is filled into the container first. Thereafter, the open neck of the container is sealed by the mounting cup being crimped onto the neck of the container. Now, the liquid is filled into the pouch via the valve in the mounting cup, so that a desired total pressure is achieved inside the pouch/container. Although the “bag-in-can” concept has been known for some time, it has not been suggested to use the concept in connection with a manually operated dispensing device for delivering ophthalmic solution to the surface of an eye.
[0007] None of the above identified prior art devices is directed to a manually operated dispensing device for delivering ophthalmic solution to the surface of an eye, which device can be used to deliver the solution in a desired non-excessive spray pattern, with a desired impact pressure and a desired droplet size, very soon after an eye contamination has occurred, without the need of special instructions for the use of the device, and which device can be used over and over again while retaining the sterilization of the solution.
[0008] Therefore, it is a primary object of the present invention to provide a manually operated pressurized dispensing device for delivering ophthalmic solution to the surface of an eye, very soon after an eye contamination has occurred, without the need of special instructions for the use of the device, and which can be operated from any position.
[0009] It is a further object of the present invention to provide a manually operated pressurized dispensing device for delivering ophthalmic solution to the surface of an eye, in a desired non-excessive spray pattern, with a desired impact pressure and desired droplet size.
[0010] It is a further object of the present invention to provide a manually operated pressurized dispensing device for delivering ophthalmic solution to the surface of an eye, which device can be used over and over again while retaining the sterilization of the solution.
SUMMARY OF THE INVENTION
[0011] The manually operated dispensing device of the present invention is provided for delivering ophthalmic solution to the surface of an eye, in a desired non-excessive spray pattern, with a desired impact pressure and desired droplet size, very soon after an eye contamination has occurred, without the need of special instructions for the use of the device, over and over again while retaining the sterilization of the solution.
[0012] The device according to the invention comprises a pressure container having a closed bottom and an open top defining a neck, for accommodating a pressurized gas and a pouch; a sealed pouch, for said ophthalmic solution, made of a barrier material and exhibiting a valve which is integrated with a mounting cup adapted to fit the neck of the container; and an actuator adapted to fit the mounting cup of the sealed pouch, comprising a nozzle member including a cylindrical tube member, adapted to interact with the valve, and an actuator button for activating the interaction between the nozzle member and the valve, in order to accomplish said desired spray pattern.
[0013] The nozzle member of the present pressurized dispensing device is designed to give said desired non-excessive spray pattern, with a desired impact pressure and a desired droplet size. Especially, this is achieved by the design of the cylindrical tube member, which exhibits a venturi passageway including a nozzle outlet which creates a conical spray pattern which diverges at an angle α in the range of between 6 and 12° from the longitudinal axis C of the venturi passageway. By this nozzle member, being operatively connected with the pouch inside the container, there is provided a flow of said ophthalmic solution of 1-20 ml/10 sec, preferably 2-16 ml/10 sec, at a major droplet size of 20-400 μm, preferably 35-90 μm. A small droplet size will efficiently give a large specific rinsing surface of the spray and also the impact pressure will be low for each droplet, thus creating a comfortable spray pattern to the eye. An impact pressure of at least 0.1 g/cm 2 but not more than 1 g/cm 2 has proven to be efficient, yet comfortable to the eye.
[0014] By the bag-in-can concept, there is provided a pressurized device, adapted to give a very even and constant flow of the solution, without the use of halogenated drive gas. Moreover, the compressed drive gas, which normally consists of nitrogen gas or air, does not come in contact with the solution inside the pouch. The pouch is beneficially designed in an essentially diffusion proof multi-layer laminate, known per se and preferably comprising polypropylene (PP), oriented polyamide (OPA), aluminum (ALU) and polyethylene (PET). Advantageously, but not necessarily, the pouch is provided with longitudinal sealing edges, protruding at least 5 mm, preferably at least 7 mm, and even more preferred at least 10 mm from a filling body of the pouch. The filling body of the pouch has a lateral dimension, in its filled state, which is fairly equal or somewhat larger than a lateral dimension of said container. By the sealing edges (or flanges), the pouch is, to some extent, secured inside the container. This is the case since the protruding sealing edges will be pressed against the inner wall of the container. To further improve the securing of the pouch, in order for the connection between the mounting cup and the pouch not to let go if the container is dropped into the floor or the like, the inner surface of the container and/or the outer surface of the pouch may be provided with a friction enhancing surface.
[0015] Thanks to the device having an appearance identical to a conventional pressurized can (normally including a halogenated drive gas), there is not needed any special instructions for the use of the device. This means that any person who has received chemical or physical contamination in the eyes, may use the device directly, without hesitation about how to use it. Moreover, the ophthalmic solution will be delivered immediately, when the actuator button is being pressed down, which means that no time is lost before the eyes can be rinsed. A further major advantage is that no free space above the eyes of the individual is required for treatment, since the shower can be activated from any position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0017] [0017]FIG. 1 is a perspective view of a pouch which is integrated with a mounting cup, for mounting on the neck of the can.
[0018] [0018]FIG. 2 is a cross-sectional view of the can and pouch with a nozzle member to be used, in order to provide the desired spray flow.
[0019] [0019]FIG. 3 is a cross-sectional view of the dispensing device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0021] In FIG. 1 there is illustrated a pouch 1 to be accommodated inside a pressure container. The pouch comprises a bag 4 , which is flat in its unfilled state, and which is formed by an essentially diffusion-proof multi-layer laminate. The volume of the bag 4 is 30-400 ml, the two most preferred volumes being 75 ml and 200 ml, respectively. At the lower end 2 of the bag, there is a folded, preferably double-folded, edge. Along the longitudinal edges of the bag 4 , there are sealing edges 3 , normally consisting of welded edges. According to a preferred embodiment of the invention, these sealing edges 3 exhibit a certain width, which will result in a fictional securing of the bag inside the container. At the upper end of the bag 4 , there is arranged a mounting cup 5 , which is sealingly connected, preferably welded, to the bag 4 at a connection member 6 . In this regard, the bag should not be too big, in order for the bag 4 not to let go from the connection member 6 if the device is dropped onto the floor. The connection member 6 consist of a preferably plastic tube, accommodating a conventional non-return valve 6 A (see FIG. 2) including a spring—valve body—valve seat assembly, which as is well known per se opens up when the valve body 6 A is forced out of contact with the valve seat 6 B, counteracting the resilient force of the spring. The exit of the connection member 6 , for the ophthalmic solution contained in the bag, is a small hole 7 in the mounting cup 5 . The top part of the mounting cup 5 consists of a metal cup 8 , provided with a double walled circumference, below which there is arranged a gasket (not shown).
[0022] In FIG. 2 there is illustrated a cross sectional view of the portion of a container with a pouch and a preferred actuator/nozzle member 9 for the device according to the invention. The nozzle member 9 is preferably made of a plastic material and exhibits a lower connection part 10 , adapted to fit the inner part of the mounting cup 5 . The nozzle member 9 further comprises a centrally arranged cylindrical tube member 11 , extending essentially all the way down to and through the lowermost part 10 of the nozzle member 9 , and exhibiting an open end 11 A at that location. The tube end 11 A abuts the upper surface of the valve body 6 A, which is arranged with grooves (not shown, but known per se). When the valve body 6 A is moved downwardly out of contact with the seat (e.g. rubber ring) the solution in the pouch can move into the tube 11 via said grooves. The tube member 11 exhibits a bend 12 , level with a nozzle outlet 13 . After the bend 12 , the tube member 11 extends essentially horizontally towards the nozzle outlet 13 . Between the bend 12 and the outlet 13 there is arranged a kind of a screening device 14 , which as is known per se can guarantee the desired flow even if any undesired particle would enter the tube 11 . At the nozzle outlet, there is provided a venturi passageway 13 , including a constriction which forms the smallest diameter of the tube member. Thereby, there is achieved a desired conical spray pattern from the nozzle outlet 13 . The cylindrical tube member 11 normally exhibits a diameter of about 1-2 mm, and a smallest diameter, at the venturi passageway 13 , of less than 1 mm, preferably 0.05-0.7 mm for an isotone solution of sodium chloride. Depending on the type of solution, especially depending on its viscosity, the smallest diameter of the venturi passageway is optimized together with the pressure inside the container and the volume of the bag in order to yield a spray time of normally 5-15 minutes.
[0023] The actuator/nozzle member 9 also includes an actuator surface 15 , for the pressing with a finger of an operator. FIG. 2 also shows a side view of a cylindrical pressure container (or can) 16 , which preferably is made of aluminum or steel and which suitably is designed to withstand an internal pressure of at least 12 bar, preferably at least 18 bar. The volume of the container is 1 liter at the most, preferably 500 ml at the most. The two most preferred volumes are 140 ml and 335 ml, respectively. The container 16 is provided with an open top 17 defining a reinforced neck with a diameter that corresponds to a diameter of the double walled circumference of the mounting cup 5 . Accordingly, as can be seen from FIG. 2, the mounting cup 5 may be arranged on the neck 17 of the container 16 , with the bag/pouch 4 being arranged inside the container. Thereafter, the nozzle member 9 is arranged on the mounting cup. Preferably, there is arranged a plastic dust cap on top of nozzle member 9 (not shown).
[0024] The pouch 1 exhibits, as has been previously described, at least two longitudinal sealing edges 3 . These edges (or flanges) 3 , together with the fact that the filling body of the pouch has a lateral dimension, in its filled state, which is fairly equal or somewhat larger than a lateral dimension (i.e. the diameter) of the container 16 , assures that the pouch 1 is securely arranged inside the container 16 . The width of the sealing edges 3 may be optimized, i.e. increased in relation to the width of conventional sealing edges, in order to further improve the securing of the pouch inside the container. Furthermore, the inner surface of the container 16 and/or the outer surface of the pouch 1 may be provided with a friction enhancing surface, such as a rugged surface.
[0025] When the actuator surface 15 of the nozzle member 9 is pressed on, this will result in the entire nozzle member being pressed down, whereby the lower end of the tube member 11 will be forced into the hole 7 of the mounting cup 5 and effect release of the valve body 6 A so that a flow of ophthalmic solution will take form in the tube member 11 , because of the pressure acting on the pouch 4 within the can 16 .
[0026] In an alternative male-type embodiment of the nozzle member (not shown), as is well known per se, the vertical part of the tube member is formed by a separate part, which is mounted in the hole 7 of the mounting cup 5 . In this case, the nozzle member 9 exhibits a larger diameter vertical receiving part for receiving the separate part of the tube member, but the outlet is designed as described above in order to produce the desired function.
[0027] In FIG. 3 there is shown a further cross-sectional view of the dispensing device with a filled pouch 4 and, wherein the design of the valve 6 is slightly different compared to FIG. 2. Here the tube end 11 A protrudes into a cavity within the valve body. The function however, is the same as described in connection with FIG. 2. It is also shown how the vertical part of the cylindrical tube member 11 in the nozzle member 9 will protrude into the hole of the mounting cup 5 . Furthermore, it is shown how the double walled circumference of the mounting cup 5 will enclose the reinforced neck 17 of the container 16 .
[0028] The procedure for filling the device with a pressurized gas (propellant), such as air or N 2 , and with an ophthalmic solution, such as an isotone (0.9%) sodium chloride solution, is as follows. The container 16 is filled with the gas, via the open top of the container, to a pressure of about 2 bar. Thereafter, while retaining the pressure inside the container 16 , the mounting cup 5 is mounted on the neck of the container and the double walled circumference of the mounting cup is mechanically crimped (plastic deformation) onto the neck 17 of the container 16 . Now, the solution is filled into the pouch 1 , through the valve in the connection member 6 of the pouch. The non-return valve is in this connection mechanically opened to allow a flow in the “wrong” direction. The pouch is filled to take about 60% of the total free volume inside the container, whereby the pressure inside the container is increased to 4-7 bar, or about 5 bar. The filling is aseptically performed, resulting in 50 CFU/ml at the most (CFU=Colony Forming Units). After the filling, the whole container is sterilized by gamma radiation, of min 25 kGrey. Finally, the nozzle member 9 and a possible dust cap is mounted on the mounting cup 5 and the device is ready for use.
[0029] In order for the pressure inside the container not to fall too quickly during use, it may be preferred to have a higher initial gas/solution ratio inside the container, whereby e.g. 45-55%, or about 50%, of the total free volume consist of gas, the rest consisting of the solution. In this embodiment it may be especially preferable to provide the pouch with extra wide sealing edges and/or to provide the inside of the container and/or the outside of the pouch with a friction enhancing surface, in order to properly secure the pouch inside the container.
[0030] In an alternative, not preferred and not shown, embodiment, the filling of the pressurized gas may take place through a separate valve in the wall of the container, after the mounting cup has been crimped onto the neck of the container. In this case, the solution may be filled into the pouch before the gas is being filled into the container. The filling ratio and the total pressures will however be the same as is described above.
[0031] The invention is not limited to the above described preferred embodiments, but may be varied within the scope of the claims. A further advantage of the device is that it may be used for wound wash as well, at least when the solution consists of an isotone sodium chloride solution.
[0032] It is also realized that the concept of the invention can be extended to other uses of the device shown herein. Certain adaptations of the nozzle member and/or of other features of the device may in that case be necessary, but nevertheless the device to be used may be essentially similar to the device shown herein, filled with some other solution. A conceivable field of use is the veterinary field, such as a spray device for iodine, for a disinfective solution such as chlorhexidine or for a liniment. Other uses within the human treatment field are also conceivable, such as a device for a nose spray, or a spray device for a saliva substitute, for a disinfective solution such as chlorhexidine, for wound wash, for personal hygiene, for a gel or solution for treatment of burn injuries, for a NaCl gel for natural skin moisturizing, for a gel or solution for local anaesthetics, such as Xylocain or for a plaque detector.
[0033] Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
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A manually operated dispensing device for delivering ophthalmic solution to the surface of an eye in a desired spray pattern with an impact pressure on the eye that is comfortably tolerated by an individual. The device comprises a pressure container having a closed bottom and an open top defining a neck, for accommodating a pressurized gas and a pouch; a sealed pouch, for said ophthalmic solution, made of a barrier material and exhibiting a valve which is integrated with a mounting cup adapted to fit the neck of the container; and an actuator adapted to fit the mounting cup of the sealed pouch, comprising a nozzle member including a cylindrical tube member, adapted to interact with the valve, and an actuator button for activating the interaction between the nozzle member and the valve, in order to accomplish said desired spray pattern.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and is a continuation of the co-pending patent application, U.S. patent application Ser. No. 12/727,915, filed on Mar. 19, 2010, entitled “METHODS AND APPARATUS FOR SELECTIVE SPRING PRE-LOAD ADJUSTMENT”, by Christopher Paul Cox et al., Attorney Docket Number FOX/F0035, and assigned to the assignee of the present invention, the disclosure of which is hereby incorporated herein by reference in its entirety.
[0002] The U.S. patent application Ser. No. 12/727,915 claims priority to and benefit of U.S. Provisional Patent Application No. 61/161,620, filed on Mar. 19, 2009, entitled “METHODS AND APPARATUS FOR SELECTIVE SPRING PRE-LOAD ADJUSTMENT” by Christopher Paul Cox et al., with Attorney Docket No. FOXF/0035L2, which is incorporated herein, in its entirety, by reference.
[0003] The U.S. patent application Ser. No. 12/727,915 claims priority to and benefit of U.S. Provisional Patent Application No. 61/161,552, filed on Mar. 19, 2009, entitled “METHODS AND APPARATUS FOR SELECTIVE SPRING PRE-LOAD ADJUSTMENT” by Christopher Paul Cox et al., with Attorney Docket No. FOXF/0035L, which is incorporated herein, in its entirety, by reference.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] Embodiments of the present invention generally relate to a user-adjustable spring for use in a shock absorber.
[0006] 2. Description of the Related Art
[0007] Integrated damper/spring vehicle shock absorbers often include a damper body surrounded by a mechanical spring. The damper often consists of a piston and shaft telescopically mounted in a fluid filled cylinder. The mechanical spring may be a helically wound spring that surrounds the damper body. Various integrated shock absorber configurations are described in U.S. Pat. Nos. 5,044,614; 5,803,443; 5,553,836; and 7,293,764; each of which is herein incorporated, in its entirety, by reference.
[0008] The spring mechanism of many shock absorbers is adjustable so that it can be preset to varying initial states of compression. In that way the shock absorber can be adjusted to accommodate heavier or lighter carried weight, or greater or lesser anticipated impact loads. In motorcycle racing, particularly off-road racing, shock absorbers may be adjusted according to certain rider preferences.
[0009] U.S. Pat. No. 5,044,614 (“the '614 patent”) shows a damper body carrying a thread 42 . A helical spring 18 surrounds the damper body where the two form an integrated shock absorber. The compression in the helical spring 18 may be pre-set by means of a nut 48 and a lock nut 50 . Because the nut 48 and lock nut 50 must be relatively torqued to prevent nut 50 rotation upon final adjustment, the shock absorber must typically be removed from its vehicle in order to allow torquing wrench access. Once the spring 18 is in a desired state of compression, lock nut 50 is rotated, using a wrench, up against nut 48 and tightened in a binding relation therewith.
[0010] The system described in the '614 patent requires that the user be able to access a large amount of the circumference of the shock absorber, and specifically the nut 48 and lock nut 50 , with a wrench (e.g. col. 4, lines 15-17). Unfortunately many shock absorbers, as mounted on a corresponding vehicle, are fairly inaccessible, and have limited surrounding wrench space because of other surrounding vehicle hardware and/or, as in the instant case, a separate damping fluid reservoir or “piggyback.” What is needed is a shock absorber having a spring that can be readily adjusted while the shock absorber is mounted on a vehicle. What is needed is a motorcycle “monoshock” having a spring that can be easily adjusted without removing the shock from the motorcycle. What is needed is a shock absorber having a spring where the state of spring adjustment is constantly indicated and easily visible while the shock is mounted on a vehicle.
SUMMARY
[0011] The present invention generally relates to a suspension comprising a spring assembly having a threaded member at a first end for imposing axial movement in the spring as the spring is rotated and thereby rotating the threaded member relative to a second component. In one embodiment, the system includes a damper for metering damping fluid and a rotatable spring member coaxially disposed around the damper and rotatable relative to the damper. In one embodiment an adjustment assembly includes a spring adjustment nut (e.g. follower nut) and clamp with the adjustment nut disposed on a threaded portion of the second component. When the clamp is loosened, the adjustment or “follower” nut rotates with the spring which is rotated by a user and the rotation thereby compresses or decompresses the spring as the nut moves axially (by thread pitch) along the threaded second component. In one embodiment, the clamp includes an indicator that cooperates with markings on the second component to indicate the compression state of the spring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0013] FIG. 1 is a perspective view of a shock absorber having a user-adjustable spring.
[0014] FIG. 2 is an exploded view of a follower nut and clamp, and 2 A is a section view thereof.
[0015] FIG. 3 is an enlarged view showing an interface between the clamp, follower nut and spring.
[0016] FIG. 4 is a perspective detailed view of the shock absorber.
DETAILED DESCRIPTION
[0017] FIG. 1 shows an embodiment of a reservoir type shock absorber 100 . The shock absorber includes a second component, such as in this embodiment a damper body 120 , with a rod 125 extending therefrom and a reservoir 150 is in fluid (e.g. damping fluid such as hydraulic oil) communication with the damper body 120 . The shock further includes a helical spring 175 annularly disposed about the damper body 120 and captured axially between a bottom clip 180 at a lower end and an adjuster assembly 200 at an upper end. An outer surface of the damper body 120 includes threads 190 that facilitate rotation of nut 210 and corresponding axial movement of the adjuster assembly 200 relative to the body 120 .
[0018] One embodiment of the adjuster assembly 200 is best appreciated with reference to all of the Figures and comprises a follower nut 210 and a clamp 250 . In one embodiment the follower nut 210 includes a pin 215 for fitting into a hole 216 (shown in FIG. 2 ) in a flange of the nut 210 . Referring to FIG. 3 , the pin 215 rotationally indexes the follower nut 210 to the spring 175 at an interface 300 between an abrupt end 470 of the wound wire and an upwardly inclined upper surface of the same wound wire in the coil preceding (i.e. directly underneath) the abrupt end 470 of the helical spring 175 . In one embodiment, pin 215 extends axially (i.e. parallel to the longitudinal axis of the shock absorber 100 ) downward from follower nut 210 and extends into the interface space 300 . Due to interference between the pin 215 and the abrupt end 470 of spring 175 in one direction (referring to FIG. 3 ) and the helical angle of the spring wire in the other direction where the end and the angle combined form an axial recess at an upper end of the spring 175 , rotation of the spring 175 will interfere with the pin (or key or tooth) 215 and impart a rotational force (via the pin 215 ) to the follower nut 210 . Conversely, rotation of the follower nut 210 will carry the pin 215 and a rotational force will be correspondingly transmitted to the spring 175 . In one embodiment (not shown) an upper portion of the spring 175 adjacent the abrupt end 470 is tapered to increase the surface contact between the spring and a lower end of the follower nut 210 (i.e. the spring end is ground “flat”). In one embodiment (not shown) the flattened last coil portion of the upper end of the spring includes an axial hole drilled therein for receiving the portion of pin 215 that protrudes from hole 216 . In one embodiment the upper end of the spring is castellated and the lower surface 212 of the nut 210 is castellated such that the castellations of the nut and the spring are interengageable for rotationally fixing the nut 210 to the spring 175 . In one embodiment, the nut 210 includes a ratcheting pawl set on a lower surface thereof and the spring includes suitable beveled one way castellations on an upper surface thereof (or vice versa) and the spring and the nut are therefore rotationally engaged in one rotational direction only (depending on the sense of the ratchet set) and relatively freely rotatable in the other rotational direction. In one embodiment, the spring 175 is rotatable in relation to the bottom clip 180 . In another embodiment the bottom clip 180 is bearing-mounted (e.g. with a race of ball bearings disposed between a lower end of the spring and an upward facing surface of the bottom clip 180 in axially abutting relation to each) to a shock mount 195 and thereby facilitates easier rotation of the spring 175 relative to the damper body 120 (by reducing the relative apparent coefficient of friction between the bottom clip and the lower end of the spring). In one embodiment, the spring comprises a plurality of springs axially abutted one with another where each of the springs has a different spring rate. In one embodiment, at least one spring of a shock absorber is wound having a compound spring rate. It is worth noting that as the spring 175 is placed in greater states of compression, the friction force between the spring 175 and its axial abutments at the clip 180 and the follower nut 210 are increased.
[0019] While the follower nut 210 is a separate component in some embodiments, it will be understood that the nut can be integral with the spring 175 whereby one end of the spring is therefore effectively threaded to the damper housing and axially adjustable upon rotation of the spring while an opposite end of the spring is axially fixed but rotationally movable relative to the damper body. In one embodiment, the clamp member can also be formed to simply include a threaded member, for instance, that interacts with the damper body to prevent rotation between the threads of the integral spring/nut/clamp and the threaded damper body. In one embodiment, the bottom portion 180 includes a cylindrical member, or body, (not shown) axially and upwardly disposed within and along the spring 175 . In one embodiment the cylindrical member is threaded along an axial exterior length thereof. In one embodiment an adjustment assembly 200 is located between bottom clip or annular “lip” 180 and a lower end of the spring 175 . Much as has been previously described in relation to threads 190 and the nut 210 , in one embodiment the threads 211 on an inner diameter of nut 210 are engaged with threads on an outer diameter of the cylindrical member (not shown). The pin 215 engages a recess 300 at a lower end of the spring 175 . As previously described, rotation of the spring 175 correspondingly rotates the nut 210 , via pin 215 , and the nut 210 translates axially along the cylindrical member thereby increasing or decreasing the compression in the spring 175 depending on the direction of rotation and the directional “sense” of the threads. In one embodiment the cylindrical member (not shown) has an inner diameter that is larger than the outer dimensions of the spring and is disposed axially upward along the shock and outside of the spring. A nut is threaded on an outer diameter thereof and engaged with an end of the spring and the cylinder is threaded on an inner diameter thereof and the nut, cylinder and spring cooperate as principally described herein to facilitate adjustment of compression in the spring. In one embodiment the spring includes an assembly 200 and corresponding threaded sections (e.g. 190 , cylindrical member) at each of its ends. In one embodiment the threads at each end are opposite in “sense” so that rotation of the spring increases or decreases compression in the spring twice as fast as a single threaded end version. In one embodiment threads at one end are of a different pitch than threads at the other end of the spring 175 .
[0020] FIGS. 2 and 2A show details of embodiments of the clamp 250 and follower nut 210 . In one embodiment the follower nut 210 is cylindrical (with varying diameters along its length) generally with a cut though or split 220 , giving it the form of a “C” ring. The clamp 250 is also in the form of a “C” ring, being generally cylindrical and having its own cut or split 230 . As can be seen in FIG. 2A , the clamp 250 fits over the follower nut 210 . In one embodiment the clamp 250 is expanded elastically at the split 230 to clear a lip 212 at a smaller-diameter end of the follower nut. Once the clamp 250 has cleared the lip, it is returned to a “relaxed” state surrounding a portion of the nut 210 and is rotationally movable relative thereto. The clamp 250 may then rotate about the follower nut 210 (and the follower nut 110 may rotate within the clamp 250 ) but the clamp 250 is retained axially on the follower nut 210 by lip 212 . In one embodiment a screw 260 , with a suitable washer is inserted into the clamp 250 but not tightened until such time as rotational and axial retention of the follower nut 210 on the damper body 120 (e.g. because spring adjustment is complete) is desired. In one embodiment, the adjuster assembly 200 , with its nut 210 and clamp 250 , is threaded onto threads 190 of body 120 , and is moved axially (e.g. by rotation of the threaded ( 211 ) nut 210 about threads 190 ) until an indicator 255 (best seen in FIGS. 2 and 4 ) formed on the clamp 250 is located adjacent the reservoir 150 . In one embodiment a curved surface 256 of the indicator 255 , corresponding generally to the curved shape of the reservoir body is aligned with the exterior of the reservoir 150 and the follower nut 210 and clamp 250 may be axially translated further toward a lower end of the shock 100 by rotation of follower nut 210 (while clamp 250 remains aligned with reservoir 150 via indicator 255 ). Tightening the screw 260 “closes” the C-shaped clamp 250 and correspondingly closes the follower nut 210 thereby preventing the follower nut 210 from rotating on the threaded surface 190 of the damper body 120 , and therefore frictionally (e.g. as a clamp) locking the nut 210 to the damper body and thus retaining the user-adjusted compression in the spring 175 .
[0021] In one embodiment the indicator 255 connected on clamp 250 , and rotationally fixed relative to the clamp 250 , serves at least two purposes. Its curved surface 256 conforms to a portion of an exterior of the reservoir 150 , thereby preventing rotation of the clamp 250 during rotation of the spring 175 . As such the orientation of screw 260 is maintained relative to the shock absorber and the vehicle on which the shock absorber is mounted. Correspondingly, the screw 260 is maintained in an accessible location for tightening and loosening to facilitate spring 175 adjustment while the shock absorber remains mounted on the vehicle. Second, the indicator 255 serves to indicate axial compression state of the spring 175 relative to a scale 400 (referring to FIG. 4 ).
[0022] In one example, the clamp 250 is loosened by inserting an appropriate hex or blade type wrench or screw driver (not shown) through a predetermined shock absorber access space available in the vehicle (vehicle such as a monoshock rear shock motorcycle) and rotating screw 260 counterclockwise (assuming a right hand thread screw 260 ) to loosen the clamp. Once the clamp 250 is loose, the spring 175 can be manually gripped, through the access space, by a user and rotated manually, for example, in one embodiment having right hand threads 190 from the top axial view of the shock absorber, clockwise as viewed from the upper end, to increase compression or pre-load in the spring 175 . In that embodiment rotating the spring 175 counterclockwise as viewed from above reduces pre-load of the spring 175 (or vice versa depending on the sense of threads 190 ). As previously described, such rotation of the spring 175 causes rotation of the follower nut 210 and corresponding axial translation of the follower nut 210 (based on the pitch of the threads 190 ) relative to the damper body 120 and along threads 190 . Axial movement of the follower nut 210 , relative to non-axially moving bottom clip 180 , increases or decreases compression pre-load in spring 175 . In one embodiment, when the desired pre-load is obtained, as indicated by movement of the indicator 255 , which moves axially with the nut 210 , relative to the scale 400 , the clamp 250 is retightened by rotating screw 260 clockwise. It should be noted that the scale 400 may be placed on any suitable and axially static component relative to the follower nut 210 /clamp 250 and the indicator 255 may be structured to “point” appropriately thereto. In one embodiment the numerical markers on the scale 400 are indicative of a percentage of compression preload in the spring. In one embodiment, the scale and indicator are visible from an exterior of an assembled vehicle with the shock absorber having the scale and indictor mounted thereon. In one embodiment, the scale 400 and indicator 255 “pair” comprise a longitudinal wire coil and permanent magnet. Position of the magnet relative to the coil is indicated by a state of current through the coil and can be calibrated to correspond to a state of spring compression. In one embodiment the “scale/indicator” pair comprises a proximity sensor and a datum structure. In one embodiment an electronic “scale/indicator” pair is connected to a transmission circuit having wireless protocol capabilities, such as Garmin's ANT plus, and shock spring compression data is transmitted in real time or in packets to a user interface/output device such as for example Garmin's 705 edge GPS enabled computer. In one embodiment the shock absorber is a monoshock and is accessible and visible, while mounted in a functional position, through a limited access space of the monoshock equipped vehicle.
[0023] While the foregoing is directed to certain embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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A method and apparatus for a suspension comprising a spring having a threaded member at a first end for providing axial movement to the spring as the spring is rotated and the threaded member moves relative to a second component. In one embodiment, the system includes a damper for metering fluid through a piston and a rotatable spring member coaxially disposed around the damper and rotatable relative to the damper.
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FIELD OF THE INVENTION
The present invention is directed to a locking orthodontic bracket that contains a mechanism that rotationally locks an orthodontic archwire within the bracket archwire slot.
BACKGROUND OF THE INVENTION
Orthodontic brackets attached to teeth transmit forces, such as produced by an archwire, to move the teeth. Brackets usually contain an archwire slot for reception of the archwire. Orthodontic brackets today are typically bonded to a tooth or welded to an orthodontic band that is cemented to the tooth.
Brackets commonly use tie wings that project upwardly and downwardly in pairs at the top and bottom of the installed bracket, respectively. These wings permit the archwire to be held within the archwire slot of the bracket by means of a twisted wire (ligature) or an elastomeric o-ring. Currently there are varieties of brackets that are self-ligating. These self-ligating brackets have taken several forms.
U.S. Pat. No. 5,094,614 to Wildman, issued Mar. 10, 1992, discloses a sliding closure that engages the front of the archwire. The closure is recessed from the front or anterior surfaces of the disclosed bracket. These sliding closures are also found in U.S. Pat. No. 2,549,528 to Russell, U.S. Pat. No. 2,671,964 to Russell et al. and in U.S. Pat. No. 3,131,474 to Johnson. Sliding closures require the archwire also to be recessed within the archwire slot before the closure can be moved over the archwire making it very difficult for the user to visually confirm that the archwire is properly seated within the archwire slot. A conventional bracket has a visual front surface adjacent to the archwire slot making it easy to see if the archwire is seated in the archwire slot. This is not true in the recessed sliding closures. The actual archwire slot surface is beneath the sliding closure. Damon solved this problem in U.S. Pat. Nos. 5,275,557 (Jan. 4, 1994), 5,429,500 (Jul. 4, 1995) and 5,466,151 (Nov. 14, 1995).
An achievement of these patents is a ligating slide within a bracket that maintains the normal features of protruding tie wings or lugs and a closure in the form of a ligating slide that can complete a continuous tube surrounding the archwire when the closure is in a closed position. This can be achieved in a Siamese or twin bracket configuration without covering or interfering with projecting extensions on the bracket.
Pletcher, U.S. Pat. No. 5,322,435, discloses a locking slide member that is flat and guided by upright slots formed along both sides of the bracket and spanning the archwire slot thereby obscuring visual access to the critical corners of the archwire slots at the side edges of the bracket. Without this visual access being clear, one installing an archwire within a bracket cannot be certain as to proper seating of an archwire within the archwire slot before the slide cover is moved to a closed position. No tie wings or lugs are included in the illustrated bracket forms.
There is a modern esthetic requirement that the brackets be small. A drawback of many self-ligating brackets the locking covers increase the size of the bracket.
Damon, U.S. Pat. No. 6,071,118, discloses a sliding cover which gives visual access to the archwire slot, but have achieved the enclosure of the sliding cover by thickening the bracket in the gingival area
A sliding spring cover, a hinged locking cover, a rotary sliding cover, a ball type rotatable cover etc. have been disclosed in different U.S. Patents. “Activa” produced by A Company, “Speed” and “Edgelock” produced by Ormco Corporation, and others are typical examples of ligature-less brackets that are commercially available.
Of all these different locking means a sliding closure has been considered desirable because it can be easily manipulated and it reduces the time required for opening and closing of the arch wire slot during periodic adjustments of the arch wire and provides more precise control of the archwire. There are other means that are more complex and difficult and expensive to manufacture. Springs used as locking means are not strong enough to hold the arch wire into the slot.
SUMMARY OF THE INVENTION
The present invention is directed to a locking orthodontic bracket. The locking orthodontic bracket is comprised of an orthodontic bracket that contains a rotating clip device for locking an orthodontic arch wire within the arch wire slot of the orthodontic bracket. The orthodontic bracket is comprised of a body containing a slot to receive an arch wire, wings for tying ligature wires, a base that is attachable to an orthodontic band or directly to a tooth surface and a central recess on the front surface of the body that extends inwardly towards the base of the bracket. The invention is a rotating clip for locking the orthodontic arch wire within the arch wire slot. Rotation of the clip in one direction leaves the archwire slot open for the insertion or removal of an archwire and rotation in the opposite direction locks the archwire in the archwire slot.
The rotating clip is comprised of a hollow cylindrical body with wings extending from the body. The cylindrical body has a circular base and two opposing vertical walls separated by opposing open sides. The opposing open sides allow for the passage of an archwire through the archwire slot and reduce friction during rotation of the rotating clip. The circular body is fitted and mechanically retained within the recess within the orthodontic bracket. The bracket recess is shaped and sized to receive the hollow circular body. The circular body and bracket recess may contain retentive devises such as circular grooves with matching ridges that also allow rotation of the rotating clip within the bracket recess. The wings extend laterally from the vertical cylindrical body over the surface of the orthodontic bracket. The tubular body is rotatable within the recess of the orthodontic bracket. The rotation moves the wings in a clockwise or counterclockwise motion. The bracket clip insertion hole can be slightly skewed from a perfect circle to allow friction grip when the clip is fully open or fully closed.
In a preferred embodiment, the tips of the wings enclose an orthodontic arch wire within the arch wire slot of the orthodontic bracket when the rotating clip is rotated counterclockwise. A clockwise rotation of the rotating clip opens the arch wire slot for placement or removal of the orthodontic arch wire. The strength transmitted to the wing tip is partially derived from the circular shape of the attached cylindrical body and the intimate fitting of the cylindrical body within the circular recess. The resulting strength is increased allowing the wings to be thinner which is advantageous for patient comfort. The underside of the wing, in one embodiment, has a bump that actively holds the archwire in the slot, as opposed to passively holding the archwire when the underside of the wing is flat. In another embodiment the rotating clip has two sets of wings wherein one pair actively engage the archwire when the rotating clip is rotated in one direction and passively holds the archwire when the rotating clip is rotated in the opposite direction. In another preferred embodiment, the locking clip wing is shaped to enclose most of the arch wire in the archwire slot. In another preferred embodiment, the underside of the locking clip wing contains a bevel to push the arch wire into the arch wire slot. In a further embodiment, the underside of the wing contains bumps for active clip design.
The bracket wall that retains the rotating clip remains open to self cleanse, reducing calculus build up and stuck moving parts. Tooth brush bristles can access the walls of bracket body. The bracket body design remains the same for both active and passive and active passive designs. The design allows the clinician to go from passive to active to conventional and back at any point in treatment. Height gauges may be used conventionally. The rotating clip does not interfere with anatomical structures, such as gums and other teeth, when in the open position. The rotating clip orthodontic bracket may be comprised of metal, plastic or ceramic or combinations thereof. Equivalent materials may be used. MIM technology can be used for the bracket body wherein retention for the clip is built within and there is a potential to use a breakaway design in MIM for one piece bracket body assembly. The door design will allow only the mesial or distal aspect of wing to be engaged on severely rotated teeth as the wing door can close around one wing while leaving the wire exiting the center of the bracket. The wire can be engaged from both the gingival and the occlusal in door design
There is an ability to cut out the facial aspect of the bracket leaves latitude to maintain slot integrity while increasing bulk of metal in body and arms , but allowing slot cover part of clip to be thin for springiness (passive/active). It can be designed with reciprocal open and closed doors. There are many designs in the clip. The designs may be passive or active with the same bracket body which can be a stand-alone twin without the rotating clip. The wings may be altered for the use of non-binding power chains for closing spaces or rotating teeth. Horizontal slots can be added lateral surfaces of the wings. Vertical and horizontal channels may be placed for accessories such as hooks and rotators.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view the body of the self-ligating orthodontic bracket;
FIG. 2 is a side view of the body of the self-ligating orthodontic bracket;
FIG. 3 is a perspective view of the rotating clip of the self-ligating orthodontic bracket;
FIG. 4 is a top perspective cutaway view of the body recess of the self-ligating orthodontic bracket;
FIG. 5 is a top perspective view of the self-ligating orthodontic bracket in an open position;
FIG. 6 is a top perspective internal view of the rotating clip resting within a cutout view of the body of the self-ligating orthodontic bracket;
FIG. 7 is a top perspective view of the self-ligating orthodontic bracket with the rotating clip in a closed position;
FIG. 8 is a top perspective internal view of the self-ligating orthodontic bracket with the rotating clip in a closed position;
FIG. 9 is a top perspective view of the self-ligating orthodontic bracket with an archwire;
FIG. 10A is a fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with beveled ends of the rotating clip arms;
FIG. 10B is a fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with beveled ends of the rotating clip arms;
FIG. 10C is a fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with beveled ends of the rotating clip arms;
FIG. 11A is fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with active bumps underside the clip arm end;
FIG. 11B is a fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with active bumps underside the clip arm end;
FIG. 12A is fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with retentive bumps underside the clip arm end;
FIG. 12B is a fragmentary side view of the self-ligating orthodontic bracket of FIG. 9 through A-A with retentive bumps underside the clip arm end.
FIG. 13 is a top perspective view of the self-ligating orthodontic bracket with cutout channels;
FIG. 14 is a cross-sectional view of the self-ligating orthodontic bracket of FIG. 13 through B-B;
FIG. 15 is a top perspective view of the self-ligating orthodontic bracket with extension tabs in an open position;
FIG. 16 is a top perspective view of the self-ligating orthodontic bracket with extension tabs in a closed position;
FIG. 17A is cross-sectional view of FIG. 16 through C-C;
FIG. 17B is a cross-sectional view of FIG. 16 through C-C;
FIG. 18A is cross-sectional view of FIG. 16 through D-D;
FIG. 18B is a cross-sectional view of FIG. 16 through D-D;
FIG. 19 is a top perspective view of the self-ligating orthodontic bracket with an index pin;
FIG. 20 is a cross-sectional view of the self-ligating orthodontic bracket of FIG. 19 through E-E;
FIG. 21 is a top perspective view of the self-ligating orthodontic bracket with a second pair of c-shaped extensions, all extensions in the open position;
FIG. 22 is a top perspective view of the self-ligating orthodontic bracket with a second pair of c-shaped extensions wherein the rotating clip is turned counterclockwise into a closed position;
FIG. 23 is a top perspective view of the self-ligating orthodontic bracket with a second pair of c-shaped extensions wherein the rotating clip is turned clockwise into a closed position;
FIG. 24 is top perspective views of a pair of self-ligating orthodontic brackets with notches and attached elastomeric chains;
FIG. 25 is a top perspective view of the self-ligating orthodontic bracket with a n attachable clip; and
FIG. 26 is a top perspective view of the self-ligating orthodontic bracket with an attachable clip and anti-rotation notches.
DETAILED DESCRIPTION OF THE INVENTION
The invention is comprised of a self-ligating orthodontic bracket assembly 1 . FIG. 1 discloses a bracket body 2 with a back 3 and a front surface 4 . The bracket body 2 has a left side 5 and right side 6 . An archwire slot 7 extends from left 8 to right 9 on the front surface 3 . Attached to the bracket body 2 are tie wings 10 positioned left 11 and right 12 . The tie wings 10 extend outwardly from the top 13 and bottom 14 . The front surface 4 of the bracket body 2 contains a cylindrical recess 15 with a circular wall 16 extending from a circular front 17 towards the body 2 back 3 ending in a circular floor. The tie wings 10 fit within front surface 4 recesses 19 in order to make the tie wings 10 flush with the bracket front surface 4 . FIG. 2 shows the bracket body 2 in cross section. FIG. 3 discloses a rotating clip 20 which is attached into the cylindrical recess 15 of FIGS. 1 and 2 . The rotating clip 20 has a circular base 21 with attached opposing columns 22 extending at right angles to the circular base 21 . Between the opposing columns 22 are open opposing sides 23 . Attached to each opposing column 22 free end is a c-shaped extension 24 . The c-shaped extensions 24 each extend horizontally with a free end 25 and an underside 26 . The attached opposing columns 22 have an outer circular periphery sized to fit the circular walls 16 of the circular recess 15 . The circular periphery contains a circular groove 27 . FIG. 4 is an enlarged view of the circular recess 15 disclosing the recess wall 16 with h a circular ring 26 which seats into the circular groove 27 of the rotating clip 20 . The circular ring 26 circular groove 27 relationship allows the rotating clip 20 to be retained in the circular recess 15 and be free to rotate. FIG. 5 discloses the invention in its preferred embodiment. The rotating clip 20 is inserted in the cylindrical recess 15 of the bracket body 2 wherein the circular base 21 is seated against the circular floor 17 . The c-shaped extensions 24 extend left 5 and right 6 on the surface of the front 4 of the bracket body 2 . The open opposing sides 23 align with the horizontal archwire slot 7 allowing an archwire to o travel continuously from the left end 8 of the archwire slot 7 to the right end 9 of the archwire slot 7 . FIG. 6 discloses the rotating clip 20 as it sits within the bracket body 2 . A circular groove 27 is shown horizontally on the outer surface of the attached opposing column 22 . FIGS. 5 and 6 show the rotating clip 20 in the open position wherein the c-shaped extensions 24 do not enclose the archwire slot 7 . In this open position an archwire may be placed and removed from the archwire slot 7 . In FIG. 7 the rotating clip 20 is rotated counterclockwise wherein the c-shaped extension 24 encloses the archwire slot 7 which would contain an archwire within the archwire slot 7 . This is called the closed position. FIG. 8 discloses the details of the rotating clip 20 as it rests within the bracket body 2 . The open opposing sides 23 between the opposing columns 22 allow an archwire 30 to go between the left end 8 and right end 9 of the archwire slot 7 .
FIG. 9 discloses the rotating clip orthodontic bracket 1 with the rotating clip 20 in an open position and an archwire 30 in the archwire slot 7 . FIGS. 10A are cross sections of FIG. 9 through points A . . . A. The c-shaped extension 24 rests upon the bracket body 2 and has a free end 25 with a beveled leading edge 28 underside 26 wherein the beveled leading edge 28 facilitates the c-shaped extension 24 sliding over the archwire 30 as shown in FIG. 10B . FIG. 10C is a cross-section of the c-shaped extension 24 with a bottom side 14 that is flat 31 . In FIG. 10B , the flat 31 bottom side 14 holds the archwire 30 passively in the archwire slot 7 . FIG. 11A discloses the cross-section of FIG. 9 wherein the bottom 14 of the c-shaped extension 24 has an active bump 33 that holds the archwire 30 actively in the archwire slot 7 as shown in FIG. 11B . In FIG. 12A , the c-shaped extension 24 bottom 14 has a retentive bump 33 and a dimple 34 in the bracket body 2 . The rotating clip 20 is held in a closed position when the retentive bump 33 is seated in the dimple, FIG. 12B . FIG. 13 discloses underside bumps 19 , 35 that fit into a recess channel 41 on the bracket front 4 . The recess channel 41 guides the round bumps 35 during the rotation of the rotating clip 20 . FIG. 14 is a cross-section through B-B of FIG. 13 . A round bump 35 on the bottom surface of the c-shaped extension 24 fits into the cutout channel 41 of the bracket body 41 and a cutout channel 40 for receiving the free end of the c-shaped extension 24 contains a dimple 34 for receiving the dimple 34 on the bottom side of the c-shaped extension 24 . FIG. 15 discloses a tab 42 on each c-shaped extension 24 extending towards the archwire slot 7 . The tab 42 bottom may be smooth or may contain a bump 35 . FIG. 16 shows the same rotating clip orthodontic bracket 1 , as in FIG. 15 , wherein the C-shaped extension 24 is in a first closed position. The first closed position is where the underside retentive bump 35 shown in FIG. 14 is seated in the dimple 34 closest to the archwire slot 7 as shown in FIG. 15 . FIG. 16 discloses the tabs 42 not covering the archwire slot 7 . When the c-shaped extension 24 is rotated further counterclockwise into the second dimple, FIG. 15 , 34 , the tabs 42 enclose the archwire slot 7 . FIG. 17A shows a cross-section of FIG. 16 through C-C wherein two dimples, No. 1 dimple 43 and No. 2 dimple 44 , are in the cutout channel 40 in the first position. FIG. 17B discloses the second position wherein the round bump 35 is in the No. 2 dimple 44 which places a dimple over the archwire 30 which holds the archwire 30 actively. FIGS. 18A and 18B show FIG. 16 through D-D. FIG. 18A discloses the tab 42 with the smooth underside 26 of the tab 42 above the archwire 30 , holding the archwire 30 passively. FIG. 18B shows the tab 42 further advanced over the archwire wherein the underside 26 of the tab 42 has a bump 32 that actively holds the archwire 30 . FIGS. 19 and 20 disclose an index pin 45 .
When orthodontic brackets are placed upon teeth they are ideally positioned with the bracket slot a predetermined distance from the incisal edge or occlusal surface of the tooth. In addition, the horizontal direction of the orthodontic bracket is placed at a right angle to the long axis of the tooth. An index pin 45 , FIG. 19 , is a pin vertically attached to the orthodontic bracket that helps visualize the correct long axis placement of the orthodontic bracket during its placement. FIG. 19 shows the index pin 45 attached to the self-ligating orthodontic assembly 1 in seats 46 between the left 11 and right 12 tie wings 10 . FIG. 20 is a cross section through E-E of FIG. 19 . In addition, a measuring notch 47 shows the position of the underlying archwire slot 7 that is helpful in the vertical positioning of the orthodontic bracket.
FIGS. 21-23 disclose another preferred embodiment of the invention wherein there is a second pair of c- shaped extensions 24 . FIG. 21 shows the self-ligating orthodontic bracket assembly 1 in an open position. The first c-shaped extensions 49 have a bump 35 on the under side and the second c-shaped extensions have a flat underside 25 a . FIG. 22 shows the rotating clip 20 rotated counterclockwise wherein the underside bumps 35 engage and hold the archwire 30 actively. FIG. 23 shows the rotating clip 20 rotated clockwise wherein the second c-shaped extensions 48 have a flat undersides 25 a that engage and hold the archwire 30 passively. FIG. 24 discloses a modification of the bracket wings wherein the upper and lower left wings have horizontal notches extending to the body center from the left of the bracket and the upper and lower right wings have horizontal notches 50 extending to the center 4 of the bracket body 2 , the notches 50 allow attachment of orthodontic elastomeric power chains 51 to the upper wings 13 only or to the lower wings 14 only. Elastomeric chains 51 are a series of connected islets made from an elastic material. The elastomeric chains 51 are normally used to close spaces between teeth rotate teeth and maintain the lack of spacing between teeth. The elastomeric chains 51 normally circle all four bracket wings 10 and secure the archwire 30 in the archwire slot 7 . In the present invention, the elastomeric chain 51 does not enclose the archwire. The elastomeric chain 51 can be changed without disturbing the archwire 30 or, conversely, the archwire 30 can be changed without disturbing the elastomeric chain 51 .
The invention may include integral hooks for rubber band wear by the patient. In the alternative, channels may be placed in the invention to receive removable hooks for rubber band and other attachments. The rotating clip orthodontic bracket may be comprised of a variety of materials including metal, plastic and ceramic and decorative forms consisting of a variety of colors, glow-in-the-dark and LED lights which may be activated by the patient tapping their teeth together.
The invention, as described, is not limited to the specific embodiments described as these are preferred embodiments. The invention is claimed in any of its modifications within the proper scope of its claims.
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The present invention is directed to a locking orthodontic bracket that contains a mechanism that rotationally locks an orthodontic archwire fully or partially within the bracket archwire slot. The orthodontic bracket has a body containing a slot to receive an orthodontic archwire, wings for tying ligature wires, a base that is attachable to an orthodontic band or directly to a tooth surface and a central recess in the front surface of the body that contains the rotating clip device. The rotating clip device is rotated to enclose an orthodontic archwire within the slot.
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BACKGROUND OF THE INVENTION
This invention relates to certain compositions and articles containing a polymer of a vinyl aromatic aminimide. More particularly, it relates to compositions and articles incorporating polymeric aminimides which exhibit thermoreversible gel-forming properties and negative thixotropy.
Polymeric aminimides and their production have been reported in the chemical literature and described in patents. For example, vinyl aromatic aminimides and polymers thereof are described in the publication of B. M. Culbertson et al., Journal of Polymer Science: PART A-1, Vol. 6, 2197-2207 (1968); and in U.S. Pat. No. 3,641,145 (issued Feb. 8, 1972 to B. M. Culbertson et al.). These polymers contain the aminimide moiety ##STR1## and are described in the aforementioned patent as being soluble in water. The polymers are disclosed as having utility in the formation of polyurethanes based on the ability of the polymeric aminimides to be converted to polyisocyanates.
It has been found that the polymeric vinyl aromatic aminimides, e.g., poly (trimethylamine-4-vinylbenzimide), exhibit unusual rheological properties in an aqueous medium such that the polymers can be employed to advantage where such properties are desireably utilized. For example, it has been discovered that a polymer of trimethylamine-4-vinyl-benzimide at a 5% wt. concentration in water forms a thermoreversible gel. Negative thixotropy is exhibited where, for example, the polymer is present at a concentration of about 2.5% by weight.
SUMMARY OF THE INVENTION
According to the present invention, there has been discovered certain unusual rheological behavior of polymeric vinyl aromatic aminimides in aqueous media. In its composition aspect, the invention provides a composition exhibiting negative thixotropic or thermoreversible gel forming properties comprising an aqueous medium having therein, at a weight concentration of about 1% to about 20%, a polymeric vinyl aromatic aminimide comprising repeating units of the formula ##STR2## wherein R is hydrogen, methyl or halogen; n is zero or one; and each of R 1 , R 2 and R 3 is alkyl, aryl, aralkyl or alkaryl, or two of R 1 , R 2 and R 3 , together with the nitrogen atom, complete a heterocyclic ring. The composition, depending upon the concentration of the polymeric vinyl aromatic aminimide provides a thermoreversible gel composition or exhibits negative thixotropy, i.e., the composition thickens upon application of shear stress and relaxes upon removal of the shear stress.
In its article aspect, the present invention provides a support sheet carrying a layer of thermoreversible gel, the gel comprising a medium of water and having therein, at a concentration in the range of about 3% to about 20%, a polymeric vinyl aromatic aminimide as aforedescribed.
DETAILED DESCRIPTION OF THE INVENTION
The compositions of the present invention can be conveniently prepared by introducing the polymeric vinyl aromatic aminimide with stirring into the aqueous medium. Suitable polymers and a method for their preparation are described in the aforementioned U.S. Pat. No. 3,641,145. Preferably, the polymer will be purified, as by ultrafiltration or dialysis, prior to forming the compositions of the invention. In forming a thermoreversible gel, the polymer will be added to water at a concentration which is effective to provide gelation, generally in the range of about 3% to about 20%. A preferred range is from 5% to 10%. An example of a gel of the invention is the gel formed by adding poly (trimethylamine-4-vinyl-benzimide) to water at a concentration of 5% by weight. The resulting gel melts at about 35° C. The gel can be utilized as a vehicle or medium for various agents, photographic, therapeutic or the like, releasable thermally as desired from the gel. If desired, a gel composition of the invention can be applied as a layer to a suitable support sheet of glass, plastic or the like, e.g., polyethylene terephthalate, cellulose acetate, polystyrene or the like.
In the repeating units represented by Formula (I) hereinbefore, the R 1 , R 2 , R 3 groups can include alkyl (e.g., methyl), aryl (e.g., phenyl), alkaryl (e.g., benzyl) or aralkyl (e.g., tolyl). Two of such groups can complete a heterocyclic radical such as pyrrolidine or piperidine. Preferably, each of R 1 , R 2 and R 3 will be alkyl, such as methyl, and n will be zero. R will preferably be hydrogen. A preferred polymer for preparation of the compositions and articles hereof is a polymer comprising repeating units of the formula ##STR3##
The polymers utilized herein can be homopolymers or copolymers. Thus, comonomers which may be desired for purposes of modifying the properties of the gel as required for a particular purpose can be utilized for the production of copolymers including the repeating units of Formula (I) and/or (II). For example, acrylamide can be copolymerized with trimethylamine-4-vinyl benzimide to provide copolymers which form thermoreversible gels in water. For example, copolymers of trimethylamine-4-vinyl benzimide and acrylamide in weight proportions, respectively, of 9:1, 8:2 and 7:3 provide thermoreversible gels with water.
The polymeric vinyl aromatic aminimides are compatible with other polymers including latices and can form thermoreversible gels therewith. Thus, the aqueous medium for gel formation can contain other polymers adapted to vary the physical or chemical properties of the resulting gel and can comprise, for example, a polymeric latex of butylacrylate/diacetone acrylamide/styrene/methacrylic acid (60/30/4/6 parts by weight). Such a gel composition can be coated as a layer, for example, in a photographic film unit.
A gel composition of the present invention can include various agents adapted to a particular purpose, for example, developing agents, development restrainers dyes or other photographic agents. Biological agents such as antibodies, enzymes or pharmacological agents can be incorporated into the gel. If desired, the agent can be made available for its intended function by thermal reversal, i.e., melting of the gel structure. Stabilizing agents for the gel, such as minor amounts of salts which enhance the physical structure of the gel can be employed. Amounts of salts which effect an undesirable "salting out" precipitation are, however, to be avoided.
In many applications, it will be desireable to utilize the gel composition hereof as a layer on a suitable sheet material such as glass, or plastic, e.g., polyethylene terephthalate or polystyrene. Preferably, the support sheet will be a transparent sheet to facilitate measurement of color generation or disappearance, or density or other changes as may desireably be monitored using light transmission techniques in known manner. For example, a thermoreversible gel hereof can be coated as a layer on a transparent polyester support and the gel can be utilized as a medium for the conduct of medical diagnostic reactions evaluated or monitored with the aid of optical devices using a light beam or other light source.
The polymeric vinyl aromatic aminimides can also be employed to provide an aqueous medium with negative thixotropy. For example, the polymer can be added to water at a concentration of about 1% to about 3% to provide a composition exhibiting a thickening effect upon application of shear. Removal of the stress effects a viscosity reduction. A composition of the invention exhibiting negative thixotropy can be used for the coating of various polymeric or other coating compositions by methods utilizing a pressurized coating head, such as a coating valve, slot or orifice operating under pressure. Application of the coating composition is facilitated by thickening which occurs as the composition is passed through the coating head and which counter balances the tendency of other components of the coating composition to shear thin.
The present invention is illustrated in the following examples which are intended to be illustrative only and not limitative.
EXAMPLE 1
Into a reaction vessel containing 270 mls. of water were dissolved 30 grams of trimethylamine -4-vinyl-benzimide. The reaction vessel containing the resulting solution was flushed with nitrogen and 0.03 gram of ammonium persulfate was added. The vessel was flushed with nitrogen, stoppered and heated for 20 hours at 65° C. The resulting polymer was precipitated by addition to a non-solvent (acetone) and the resulting polymer was triturated in acetone and ground in a Waring blender. The polymer product was filtered and dried in vacuo. The product, poly (trimethylamine -4-vinyl-benzimide) was obtained in 24 gram yield.
EXAMPLE 2
The polymer obtained from EXAMPLE 1 was added with stirring to water at levels of 2.5%, 5% and 10% by weight of each composition. The physical properties of each composition were noted. Extremely weak gel formation at 0° C. was observed in the case of the composition containing the polymer at the 2.5% concentration. Good gel forming properties were observed at the 5% and 10% concentrations. The gels were heated (at a rate of 1° C./min.) from room temperature to their respective melting points, i.e., 40° C. and 48° C., respectively.
The 2.5% composition was observed to exhibit negative thixotropy at 25° C. This behavior was evaluated by oft-repeated steps of stirring the composition with a stirring rod (to observe viscosity increase or thickening) and cessation of stirring (to observe viscosity reduction).
EXAMPLE 3
A homopolymer of trimethylamine 4-vinylbenzimide was prepared at a 10% solids level using the polymerization method described in EXAMPLE 1, except that azo-isobutyronitrile was employed as a polymerization catalyst. The polymer was precipitated into acetone and recovered. The polymer was added to water at levels of 5% and 10% by weight. Each of the resulting gels was heated to its melting point, 35° C. and 48° C., respectively.
EXAMPLE 4
A coating composition comprised of water and 4% by weight of the coating composition of poly (trimethylamine-4-vinyl-benzimide) was coated onto a transparent polystyrene carrier sheet, at a coverage of about 510 mgs./ft. 2 (5490 mgs./m. 2 ). The sheet was hot-air dried and cut into sections. Sections were imbibed in the following imbibition media: water; 0.01N hydrochloric acid; 5% acetic acid solution; 0.15M sodium hydroxide; and 0.10N potassium hydroxide. Sections imbibed in the hydrochloric acid and acetic acid media showed dissolution of the polymer coating. Microscopic examination of the sections imbibed in water, sodium hydroxide and potassium hydroxide showed a gel structure in the coated polymer layer.
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Compositions and articles containing polymeric vinyl aromatic aminimides are disclosed. The polymeric vinyl aromatic aminimides exhibit unusual rheological properties in an aqueous medium. The polymers provide thermoreversible gelling properties and exhibit negative thixotropy.
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FIELD OF THE INVENTION
This invention relates to plows for tilling the earth and more particularly to a moldboard type plow which is reversible for an improved result.
BACKGROUND OF THE INVENTION
Reversible moldboard and disc type plows have been used for some time. They require an implement support which is shiftable to change the angle at which the implement is pulled through the earth as it proceeds back and forth so that the angle for one direction is the same as that for the following opposite direction.
A reversible plow throws the dirt in the same direction when travelling in opposite directions in a longitudinal path. The need for such a plow arises from the necessity to create equal furrows without leaving free spaces and to provide an even, levelled surface.
HISTORY OF THE PRIOR ART
In the past, reversible disks or an extra set of moldboards have been used so that right and left side plowing can be done, but at the cost of additional weight, equipment and power.
Reversible plows with disks fixed to a tool bar or with only one set of moldboards have also been used as in the U.S. Pat. Nos. to Gomez 4,800,963, Fowler 2,764,075, and Johnson et al. 3,305,025. Other patents of related nature are Brown 1,149,720, Dukes 2,597,079, Barrett 2,672,801, Jennings 2,724,313, Heckathorn et al. 3,042,120, Jennings 3,101,789, Watvedt 4,646,849, Korf 4,869,327, British patent 1,497,259 of Jan. 5, 1978, and U.S.S.R. patents 640,688 of January 1979 and 812,199 of March 1981.
The U.S. Pat. Nos. to Watvedt 4,603,745 and 4,825,955 disclose double plowshares mounted on a plow frame which is rotatable in a vertical plane about a shaft by the action of a pair of hydraulic cylinders and pistons.
French patent 2,390,079 of January 1979, especially FIG. 1, and Johnson et al. 3,305,025, mentioned above, especially FIG. 3, disclose hitch bars that are pivotably mounted in order to move in a vertical plane between plow angular positions.
The U.S. Pat. No. to Katayama et al. 4,553,605 discloses link arms that are movable up and down by lift rods operated by hydraulic cylinders for the purpose of tilting the implement.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a moldboard type plow in which the moldboards may be shifted to plow from either side, the shifting being done by power means controlled as required by the tractor hydraulics and able to stand up to the demanding type of plowing done by moldboards.
A further object is to provide a power operated means for tilting the frame carrying the moldboards in order to adjust the depth of cut of the bottom of the furrow.
A further object is to provide a hydraulic hookup for the moldboard shifting cylinders and the frame tilting cylinder(s) in which the cylinders are operated sequentially, instead of simultaneously, thus reducing the hydraulic pressure required for the operation, and in which all cylinders are locked following actuation in order to hold the moldboards in the adjusted plowing position.
The foregoing objects are accomplished by the use of a central moldboard carrying beam that is pivotally mounted in a frame having hitch connections, the beam being connected to trunnion mounted cylinder and piston assemblies that control the travel angle of the moldboards and the attitude or angle of the hitch connections being vertically shiftable by auxiliary cylinder and piston assemblies in order to adjust the tilt of the moldboards.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective from the right side of a preferred embodiment of the invention;
FIG. 2 is a perspective to an enlarged scale from the left side of the same embodiment;
FIG. 3 is a fragmentary perspective from the rear of the forward portion of the apparatus;
FIG. 4 is a plan view indicating the pivotal movement of the beam which carries the moldboards;
FIG. 5 is a section to an enlarged scale on the line 5--5 of FIG. 4;
FIG. 6 is a section to an enlarged scale on the line 6--6 of FIG. 4;
FIG. 7 is a section to an enlarged scale on the line 7--7 of FIG. 6;
FIG. 8 is an enlarged perspective from the left side of a modification of the invention;
FIG. 9 is a front elevation to an enlarged scale illustrating the hitch plate assembly;
FIG. 10 is a section to an enlarged scale on the line 10--10 of FIG. 8;
FIG. 11 is a section on the line 11--11 of FIG. 10;
FIG. 12 is a perspective to an enlarged scale of a moldboard;
FIG. 13 is a schematic of the hydraulic connections to the positioning and tilt cylinders; and
FIG. 14 is a schematic of hydraulic connections to the positioning cylinders and tilt cylinder of the modification.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With further reference to the drawings, there is illustrated a frame 10 having a front cross member 11, a rear cross member comprising upper and lower plates 12 and 13, right and left side members 14 and 15 extending perpendicularly rearwardly from the front cross member 11, and inclined side members 16 and 17 extending to the ends of the rear cross member 12 and 13.
At the rear of the front cross member 11 an arcuate plate 20 bridges the sides 14 and 15 for purposes which will be described. Extending upwardly from the central and forward portion of the front cross member is an upper hitch plate 22, in two parallel sections, and having a hitch pin 23 extending therethrough for the purposes of attaching to the hitch point of the tractor's three point hitch.
Spaced at either side of the upper hitch plate 22 are right and left lower hitch plates 25 and 26 each of which comprises a pair of spaced plate side members that are connected to the front cross member 11. Between the side members of each lower hitch plate is a cylinder and piston assembly including cylinders 27 and 28, pistons 29 and 30, which are connected to clevises 31 and 32 carrying hitch pins 33 and 34 projecting from the sides of the outer hitch plates where the hitch pin may be received by the lower connections of the three point hitch on the tractor. The cylinders 27 and 28 are mounted by pins 34 and 35 across the tops of the spaced hitch plates in order to permit any necessary swinging movement of the cylinder and piston assemblies.
In order to reduce the wear on the hitch plates, a replaceable and reversible metal wear plate 36 is mounted at the rear of each of the clevises 31 and 32. This protects the slot in which the pin 33 reciprocates from excessive wear.
The frame mounts a longitudinal beam which may be in two sections 40 and 41. The forward section 40 is received intermediate the upper and lower rear cross members 12 and 13 and connected thereto by a pivot 42 which permits the beam to swing laterally of the frame. The forward end of the frame has a ledge plate with upper and lower sections 45, 45 and wear strips 46, 47 which ride on the top and bottom of the arcuate plate 20 previously described, in order to support the forward end of the longitudinal beam.
In order to control the position of the longitudinal beam within the frame 10 a pair of cylinders 50 and 51 are mounted, one on each side of the beam. Thus a right cylinder 50 is mounted with its cylinder intermediate the upper and lower portions of the rear cross member 12 and 13 by a pivot or trunnion mounting 52, its piston 53 extending to a pin 54 mounted between a pair of lugs 55 which are in spaced relation from the forward end of the beam.
Similarly the cylinder 51 has a trunnion mounting 56 and a piston 57 which is connected to a pin 58 between lugs 59 on the opposite side of the beam.
It will be apparent therefore that by the simultaneous operation of the piston assemblies that the forward portion of the longitudinal beam may be angularly shifted from side to side within the frame 10.
The front and rear portions of the longitudinal beam 40-41 have a series of spaced brackets 60 which are connected to mounting plates 61 for holding a series of spaced moldboards 62.
For purposes of convenience and flexibility, as previously indicated, the longitudinal beam may be divided into two portions 40 and 41. The rear portion 41 of the beam has supports 70 and 71 for a rear wheel beam 72 for carrying a gauge wheel 73. Suitable adjusting means 74 are carried in the support 71 in order that the height of the gauge wheel may be adjusted.
With reference to FIG. 12, the moldboards 62 may be made of curved metal frame sections 90 having upper bracket means 91, central bracket means 92 and lower bracket means 93 with protective follower members 94 that aid in the control of the tractor. The frame sections 90 are faced with a wear sheet 95 secured by fasteners 96 and holder strip 97 for reducing the wear on the moldboards and the need for frequent replacement.
The hydraulic control circuit for the positioning cylinders and tilt cylinders is illustrated in FIG. 13. In this figure lines 100-101 may connect to the hydraulic control lines of the tractor. These are connected to a double dual lock out box 102.
In box 102 line 100 is connected to joints 104 and 105; line 101 is connected to joints 106 and 107.
Joints 104 is connected to lines 110 and 111 to one side of tilt cylinders 27 and 28. Joint 105 is connected to lines 113 and 114 to one side of positioning cylinders 50 and 51.
The return side of tilt cylinders 27 and 28 are connected by lines 115 and 116 to joint 106 and line 101 back to the tractor.
Similarly, the return lines 118 and 119 from the positioning cylinders 50 and 51 are connected to the joint 107 and line 120 to the line 101 to the tractor.
In the operation of the tractor hydraulics, the opening of the circuit will generally unlock the circuit with the less pressure, which is usually the positioning cylinder circuit, permitting movement of these cylinders until the plow beam goes the maximum extent and hits the stop, either on the right or the left side. At this point the pressure build up and causes the tilt cylinders to operate. After all of the hydraulic functions have been completed additional pressure will bleed over to the tractor relief. When the tractor lever is returned to neutral, the double dual lockout will lock all of the cylinders, preventing them from any movements during the plowing operation.
It will be understood that at the end of each row, the tractor three-way hitch is generally operated to raise the frame and the beam with the moldboards attached clear of the field until the tractor has turned 180° and is in position to resume plowing in the opposite direction. Then the three-way hitch is lowered in order that plowing in the opposite direction may be done. During the time that the three way hitch is raised the hydraulic circuit may be operated in order to properly position the beam with the moldboards in the proper position for plowing (See FIG. 4) and also to properly position the frame in its appropriately tilted position.
FIGS. 8-11 illustrate a modification of the invention. The modification is in the mounting by means of which the height of the left and right hitch pins are controlled. Instead of having a separate cylinder and piston assembly for each of the hitch pins, the modification includes a hitch plate pivot assembly, as particularly illustrated in FIGS. 8 and 9. The assembly includes a hitch plate 150 that is mounted on and depends downwardly from the front cross member 11, substantially centrally thereof. The hitch plate has a center pivot 152 which supports a hitch bar 153 that is pivotally mounted between left and right lower hitch plates 154 and 155. The hitch plates have openings 156 and 157, respectively, for receiving the ends of the hitch bar as it oscillates, the hitch bar carrying left and right lift pins 159 and 160.
A pair of spaced lugs 162-163 are mounted over an opening 164 on the right side of the front cross member 11 and substantially over the right lower hitch plate 155. The lug 162 carries a pivot pin 166 which mounts a cylinder 167 which operates a piston 168 connected to a web 169 of a clevis 170 which engages the hitch bar 153 by means of a pin 171.
Accordingly, by operation of the cylinder and piston assembly the hitch bar may be caused to pivot about the pivot support 152 in order to raise and lower the right and left lift pins 160 and 159. A replacement tee-shaped wear plate 173 is held by a clamp 174 connected to the hitch plate 155 and engaging the clevis 170.
In order to control the operation of the positioning cylinders and the single tilt cylinder of the modification a hydraulic hookup as indicated on FIG. 14 is provided. The hookup includes the lines 100-101 to the tractor disconnects. The line 100 is connected to joint 180 and joint 181 which are connected to lines 182 and 183, respectively, to one side of the positioning cylinders and the tilt cylinder. The other line 101 is connected to line 184 and line 185 to the other side of the cylinders of the positioning cylinders and the tilt cylinder.
Ordinarily, activating the tractor hydraulics will unlock the circuit with the lesser pressure, usually the position cylinder circuit, permitting movement of the cylinders until the plow beam hits the stop on either the right or the left side. This will then permit the tilt cylinder to function. After all of the hydraulic functions have been completed the additional pressure bleeds over to the tractor relief. When the tractor lever is returned to neutral the double dual lock-out, as previously described, will lock all the cylinders preventing any movement during plowing.
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A reversible moldboard plow has a plow carrying beam swingably mounted at the rear crossbar of a frame which carries trunnion mounted cylinders connected to the beam for moving the beam, the front of the frame carrying hitch pins for connection to a tractor hitch, the hitch pins being vertically movable in alternate relation in order to tilt the frame and the beam with the moldboards supported thereon. The hitch pins may be moved by independent cylinders and pistons or, alternately, by the movement of a transverse hitch bar on which they are mounted.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 07/160,593, filed on Feb. 26, 1988, now U.S. Pat. No. 4,904,330, which is a continuation of application Ser. No. 06/792,123, filed on Oct. 28, 1985, which has since issued as U.S. Pat. No. 4,737,229 and which is a divisional application of patent application Ser. No. 06/596,346, filed on Apr. 3, 1984, which has since issued as U.S. Pat. No. 4,584,047.
BACKGROUND OF THE INVENTION
A. Field of the Invention
This invention relates generally to printing devices, and more particularly to hand-held labelers utilizing circuitry accurately to determine the position of the printing web, and to control the operation of the printing head, preferably a thermographic printing head, in response to position signals to thereby accurately position the imprints on the web.
B. Prior Art in the United States
Hand-held labelers utilizing thermographic printing devices are known. Examples of such hand-held labelers are illustrated in U.S. Pat. No. 4,264,396 to Stewart, U.S. Pat. No. 4,407,692 to Torbeck and United States patent application Ser. No. 485,012 filed Apr. 14, 1983.
While the devices disclosed in the above-described references do provide a way to make imprints on a thermosensitive web, they do not contain certain of the features provided by the device of the present invention. For example, when printing with a thermal printing device, particularly with a high density printing device such as one of the devices illustrated in the aforementioned U.S. Pat. No. 4,407,692 and application Ser. No. 485,012, it is necessary accurately to control the timing of the energization of the various printing elements as a function of the position of the web. For example, in such a system, the web is continously fed, and the appropriate printing elements must be energized at the precise time that the portion of the web on which the imprinting is desired is positioned adjacent the printing head. The difficulty of the problem is further compounded by the fact that each of the printing elements has a length and a width of only a few mils. As a result, the position of the web or the timing of the energization of the printing elements, must be precisely controlled to avoid printing gaps and changes in print density, as well as changes in character shape, particularly when the speed of the web varies as it passes the printing head, as for example, in the case of a labeler having a hand advanced web.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improvement over the prior art systems.
It is another object of the present invention to provide a hand-held labeler that includes a system for precisely sensing the position of the web and controlling the energization of the printing elements in accordance with the web position in order to position the imprints on the web with great accuracy.
It is yet another object of the present invention to provide a hand-held labeler that utilizes a web position sensing system that is particularly usable with a thermographic printing device.
It is yet another object of the invention to provide a thermographic hand-held labeler that minimizes the possibility of damage to the printing device.
It is yet another object to provide a hand-held labeler having a system that senses the position of the web with great accuracy.
It is yet another object of the invention to provide a hand-held labeler that has a system that senses the position of the web to an accuracy of a few mils.
It is yet another object of the present invention to provide a hand-held labeler having a system that senses the position of the web and controls the printing device to compensate for variations in the speed of the web.
It is yet another object of the invention to provide a hand-held labeler that utilizes a web position sensing system that is usable with hand advanced and motorized web advancing mechanisms.
Therefore, in accordance with a preferred embodiment of the invention, there is provided a hand-held labeler utilizing a microprocessor-based control system that senses the position of the web and controls the operation of the printing head in accordance with the position of the web in order to assure that any imprints are accurately positioned on the web, and on any labels cut from the web. The system employs a precise timing disc that is coupled to the label advancing mechanism. The timing disc cooperates with a sensor, such as, for example, an optical sensor that senses the position of indices on the timing disc, and provides a signal representative of web position. The timing disc includes at least one and preferably more home position indices that defines the boundary between two successive labels, one or more position determining indices and a warning index disposed adjacent to the label boundary defining index that informs the system that the label boundary is approaching. The indices are sensed by the sensor and used to provide position indicative signals to the system for controlling the operation of the printing head.
DESCRIPTION OF THE DRAWING
These and other objects and advantages of the present invention will become readily apparent upon consideration of the following detailed description and attached drawing, wherein:
FIG. 1 is a perspective view of a hand-held labeler constructed in accordance with the principles of the present invention;
FIG. 2 is a system block diagram of the logic circuitry controlling the thermographic printing apparatus according to the invention;
FIG. 3 is a plan view of a thermographic print head usable with the printing apparatus according to the present invention;
FIG. 4 is a blOCk diagram illustrating one embodiment of the print head driving circuitry;
FIG. 5 is a block diagram of an alternative embodiment of the print head driving circuitry;
FIG. 6 is a block diagram illustrating the position sensing and printer control circuitry according to the invention;
FIG. 7 is a detailed illustration of the timing disc illustrated in FIG. 6;
FIG. 8 is a block diagram of the motor speed control portion of the control circuitry of the invention;
FIG. 9 is a timing diagram illustrating the operation of the motor speed control circuit according to the invention;
FIG. 10 is a logical flow diagram illustrating the operation of the control circuit according to the invention; and
FIGS. 11 and 12 illustrate circuitry for protecting the data stored in the labeler in the event of a discharged battery and when the battery is removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, with particular attention to FIG. 1, there is shown a thermographic microprocessor-controlled hand-held labeler according to the invention, generally designated by the reference numeral 10. The labeler 10 includes a housing 12 that supports a roll 14 of adhesive backed labels 16 that are supported on a backing web 18. A keyboard 20 is disposed on the housing 12 and contains a plurality of individually operable key switches 22 for entering data into the labeler. A display 24, which may be a liquid crystal or light emitting diode display, is also disposed on the housing to permit the entered data and microprocessor-generated prompting instructions to be viewed by the operator. A battery pack, which may be contained in a removable battery pack-handle unit 25 containing a battery 26 having an internal resistance 27, provides electrical power for the labeler 10. A trigger 28 is provided to initiate the label printing operation, and a label applying roller 30 is used to apply pressure to the adhesive backed label 16 when the label 16 is being applied to an article of merchandise. A label stripper (not shown) is contained within the housing 12 to separate the labels 16 from the backing strip 18. A plurality of guide rollers are provided to guide the separated labels 16 to the forward portion of the housing beneath the label applying roller 30, and to guide the backing strip to the rear of the housing beneath the roll 14.
As previously stated, the labeler according to the invention is quite versatile and is capable of printing alphanumerics, as well as bar codes including the Universal Product Code (UPC) and the European Article Number (EAN). The type of format, whether alphanumeric or bar code, is readily selected by entering the appropriate format and fonts defining data via the keyboard 20. The data to be printed, for example, price, product defining data and other information about the product such as the size, color, etc. is also entered via the keyboard 20. In addition, the number of labels to be printed may be entered. Also, a data input/output connector 32, may be provided on the housing to permit data to be entered into the labeler by an external source, such as, a remotely-located computer, and to permit the battery 26 to be charged.
Referring to FIG. 2, the keyboard 20 is coupled to a peripheral interface adapter (PIA) 40 which provides an interface between various input and output devices and a microprocessor 42. Also coupled to the peripheral interface adapter 40 are a trigger switch 44 that is controlled by the trigger 28, and a control circuit 46 that operates a motor 48 that drives a web advancing wheel 49. A detector 50 senses a mark or index on the web advancing wheel 49' or preferably on a separate timing disc 51. The control circuit 46 responds to data received from the microprocessor 42 and controls the operation of the web advancing motor 48, which may preferably be a D.C. motor. An audible alarm 52 is also connected to the peripheral interface adapter 40, and is useful for indicating to the operator that a problem or potential problem exits. For example, the audible alarm 52 may be used to indicate a discharged or faulty battery, a faulty print head, that the labeler is out of labels, a jam, or may simply be used to indicate that data entered into the device has been received. In the latter cast, the audible alarm 52, can be used to provide an audible indication each time one of the key switches 22 on the keyboard 20 is depressed.
The display 24 is coupled to the microprocessor 42 via a display driver 54. The display 24 is used to display data being inputted into the microprocessor as well as other messages such, for example, prompting and diagnostic messages generated by the microprocessor. A read-only memory (ROM) 56 is provided for storing permanent data, such as the program defining operation of the device. The read-only memory 56 may either be permanently installed in the labeler 10, or may be removably installed in a socket or the like to permit the font and/or format to be changed by changing the memory 56. In addition, a random-access memory (RAM) 58, usable for storing short term data, such as data entered via the keyboard 20, is provided, as is a non-volatile random-access memory (NVRAM) 60, suitable for storing data such as format data. The input/output connector 32 provides communications between the device and an external computer. Printing is accomplished by a print head assembly 64 that contains a print head 66 and print head driver 68 coupled to the peripheral interface adapter 40. An analog-to-digital converter 70 coupled to the peripheral interface adapter 40 senses the battery voltage or the voltage applied to the print head assembly 64, and provides a digital indication of that voltage to the peripheral interface adapter 40 so that the microprocessor may adjust the time that the print head is energized to compensate for variations in battery or print head voltage.
One example of the print head assembly 64 is illustrated in simplified form in FIG. 3. In the illustrated embodiment, the print head assembly 64 contains the print head driver 68 and the print head 66 disposed on a thin film substrate. The print head has a single line of print elements disposed transverse to the direction of travel of the web 18, and is particularly suitable for use in a hand-held labeler because of the high density of the print elements that make up the print head 66, particularly if both alphanumerics and bar codes are to be printed. One print head assembly particularly usable as the print head assembly 66 employs 224 printing elements that are each 10 mils long and 4.4 mils wide, and spaced on 5.2 mil centers. Such a configuration permits a virtually continuous line to be printed.
Each of the printing elements constitutes a resistive heating element 80 (FIG. 4) that is individually energizable by the print head driver circuitry 68 which contains a heater driver transistor 82 for each of the printing elements 80. A gate 84 controls each of the heater driver transistors 82, and an input register 86 and a data register 88 control the operation of the gates 84. Thus, if a 224-element head is used as the print head 66, 224 driver transistors 82 and 224 gates 84 must be provided, and the input register 86 and the data register 88 must each have at least 224 stages.
The input register 86 receives data serially signals applied to a clock line 92. When the input register 86 is full, the data is transferred in parallel to the data register 88 under the control of a latch signal applied to the data register 88 by a line 94. The input register 86 is then reset by a reset pulse applied to the reset line 96, and new data is supplied to the input register.
Because the resistive heating elements 80 draw a substantial amount of current, for example, approximately 50 milliamps per element, and because of the extreme density of the elements, for example, approximately 200 elements per inch, the current drain on the battery 26 would be excessive if all of the elements 80 were turned on simultaneously. For this reason, the heater driver transistors 82 are strobed by the gates 84 so that no more than one-fourth of the heater drivers 82 may be energized at any one time.
In the embodiment illustrated in FIG. 4, the strobing is accomplished by utilizing three input AND gates as the gates 84, and by enabling the gates 84 in blocks. This is accomplished by providing two block enable signals BE1 and BE2 on lines 100 and 102, respectively, and strobes ST1 and ST2 on lines 104 and 106, respectively. Each of the block enable signals is connected to one-half of the gates 84 so that one-half of the gates 84 are enabled when the BE1 signal is high, and the other half are enabled when the BE2 signal is high. The ST1 signal is applied to one-half of the gates 84 receiving the BE1 signal and one-half of the gates 84 receiving the BE2 signal. Similarly, the ST2 signal is applied to the gates 84 not receiving the ST1 signal. Thus, since it is necessary for each gate to receive one of the block enable signals and one of the strobe signals in order to be fully enabled, only one-fourth of the gates 84 are enabled at any given time. Thus, the data from the data register 88 is applied to the heater driver transistors 82 in four steps, so that no more than one-fourth of the transistors 82 may be energized at a given time.
An alternative embodiment of the print head driving mechanism is illustrated in FIG. 5. The embodiment illustrated in FIG. 5 is similar to the one illustrated in FIG. 4, except that the input register 86 is broken up into a plurality of smaller registers, for example, seven 32-stage shift registers 86' in the illustrated embodiment. Such an arrangement has the advantage that it permits data to be entered more rapidly into the system, thereby permitting a faster printing speed. This occurs because each of the seven shift registers 86' can be fed in parallel from said seven separate data lines 90'. Consequently, the data need be shifted only 32 times to load the registers 86', as opposed to the 224 shifts required to load the input register 86. However, when loading the shift registers 86' the 224 bits defining each line cannot be fed serially into the shift registers 86', but the bits must be grouped so that they may be applied to the appropriate registers. This is accomplished by taking every 32nd bit from the data defining a line, and applying it to the appropriate one of the shift registers 86'. For example, if 224 bits are used to define a line, the 32nd, 64th, 96th, 128th, 160th, 192nd and 224th bits are selected and applied to seven stages of a buffer 108 (FIG. 5). These bits are then applied in parallel to the shift registers 86'. Next, the 31st, 63rd, 95th, 127th, 159th, 191st and 223rd bits are applied to the buffer 108 and snifted to the registers 86'. The process is repeated until the first, 33rd, 65th, 97th, 129th, 161st and 193rd bits are loaded into the buffer 108 and supplied to the registers 86'. At this point, the seven registers 86' contain the bits 1-32, 33-64, 65-96, 97-128, 129-160, 161-192 and 193-224. Since this data completely defines a line, the data from the registers 86' can be transferred to a data register, such as the data register 88 (FIG. 4), or to a plurality of individual data registers 88' (FIG. 5). The output of the data register 88' can be applied to a plurality of three-input AND gates 84, or to any suitable device for limiting the number of individual elements that can be simultaneously energized.
In FIG. 5, the strobe function that limits the number of elements that can be simultaneously energized is provided by a plurality of circuits 83. Each of the circuits 83 contains 32 two-input AND gates and appropriate driving circuitry for driving the print head 66. Such a system is somewhat simpler than the system illustrated in FIG. 4 because only two-input AND gates, rather than three-input AND gates, are required. By providing three strobe signals S1, S2 and S3, the number of printing elements that can be simulataneously energized is restricted to approximately one-third of the total number of print elements.
In the embodiment illustrated in FIG. 5, the strobe signal S1 is applied to the first two and the last one of the circuits 83. The strobe signal S2 is applied to the third and fourth ones of the circuits 83, and the strobe signal S3 is applied to the fifth anc sixth ones of the circuits 83. Consequently, no more than two out of seven printing elements may be simultaneously energized when either the strobe signal S2 or the strobe signal S3 is present. Theoretically, as many as three out of seven elements may be energized when the strobe signal S1 is present, but in practice, the line of print is seldom as wide as the width of the print head 66, and consequently, it is unlikely that more than one-half of the total elements in the first anc last ones of the circuits 83 would be energized.
The control circuit 46 (FIG. 6) includes a control processor 130 that includes a read-only memory (ROM) 132 that may be located either on the same integrated circuit as the control processor 130 or in a separate package. The various components required to carry out the print control function are not shown in FIG. 6 for purposes of clarity; however, it should be understood that the microprocessor 42 of FIG. 6 must be coupled to components that are the same or analogous to the components shown in FIG. 2 to provide the printing function. The control processor 130 controls a motor drive/brake circuit 134 that selectively applies energizing or dynamic braking currents to the motor 48. An analog-to-digital converter 136 measures the back EMF of the motor 48 when it is coasting, and applies a digital representation of the back EMF to the control processor 130 in order to provide an indication of the speed of the motor 48 to the control processor 130. The detector 50 includes a light source, such as, for example, a light emitting diode 138 and a light sensitive device such as a photodetector 140 disposed on opposite sides of the timing disc 51. The detector 50 serves to detect indices formed as a series of light contrasting marks such as opaque and transparent portions on the disc 51. Preferably, the indices are fabricated as a series of apertures about the periphery of the disc 51 which are used to indicate to the system the position of the disc 51, and consequently, the position of the web 18 as it is advanced by the advancing wheel 49. Although, an optical system is used to detect the position of the disc 51, other systems may also be used.
The timing disc 51 is illustrated in greater detail in FIG. 7. The disc illustrated in FIG. 7 is fabricated from an opaque material. Because of the relatively small size of the disc 51, for example, on the order of approximately 1.25 inches in diameter, and because of the precise tolerances required, the use of electro-deposited nickel provides a convenient way to fabricate the disc. The thickness of the disc 51 is nominally 3 mils, but may vary from 2 mils to 4 mils.
As is illustrated in FIG. 6, the disc 51 is mounted on the same shaft (shaft 141) as is the web advancing wheel 49 and rotates therewith to form a shaft encoder. In the illustrated embodiment, the wheel 49 rotates one-third of a revolution each time a complete label is fed. Three home position indices in the form of three apertures 142, 144 and 146 are provided in the disc 51. In the illustrated embodiment, three home position indices are provided because the disc 51 rotates one third of a revolution each time a label is fed; however, it should be understood that if the advancing mechanism were modified such that the disc 51 rotated at a different rate, the number of home position indices would have to be changed accordingly. For example, if the disc 51 rotated one fourth of a revolution each time a label was fed, a disc with four home position indices would be used.
Following each of the apertures 142, 144 and 146 is a plurality of position defining indices in the form of a plurality of apertures or slots 148, 150 and 152, respectively (FIG. 7), which accurately define the position of the label with respect to the printing head. Although the position defining indices 148, 150 and 152 can be referred to as either apertures or slots, or by other terminology they will be referred to as slots in the following description for purposes of clarity in order to better distinguish them from the home position apertures 142, 144 and 146. A warning track is provided ahead of each of the home position indices in the form of three widened areas 154, 156 and 158.
When no labels are being printed, one of the home position defining apertures 142, 144, or 146 is aligned with the sensor 50. Each of the apertures 142, 144, and 146 is sufficiently wide to permit some backlash in the web and drive train to occur without causing an opaque area of the disc 51 to be detected by the sensor 50. This prevents the motor 48 from hunting in an attempt to keep one of the home position apertures aligned with the sensor 50. The size of the apertures 142, 144 and 146 is also selected to permit any slack in the web 18 to be taken up before one of the position defining indices is moved into alignment with the detector 50.
The width of the position defining slots 148, 150 and 152 and the width of the areas between the position defining slots is selected such that the distance between the detection of successive edges of the slots 148, 150 and 152 corresponds to a web movement that is equal to an integral multiple of the length of the print elements 80. For example, when a printing head such as the previously described printing head 66 is used, the distance between the detection of adjacent edges of the slots 148, 150 and 152 corresponds to a web travel that is equal to an integral multiple of 10 mils (the length of the print elements 80). In the timing disc 51 illustrated in FIG. 7, the integral multiple has been selected to be equal to two, thus providing a web travel of 20 mils between the detection of successive edges of the slots 148, 150 and 152. As a result, the position of the web 14 is defined in 20 mil increments.
The width of each of the warning tracks defined by the widened areas 154, 156 and 158 must be made wide enough to permit the warning tracks to be distinguished from the areas between the position defining slots. In the embodiment illustrated in FIG. 7, the width of the areas 154, 156 and 158 is selected to be approximately twice as wide as the widths of the areas separating the slots 148, 150 and 152. This provides a warning track having a width that corresponds to approximately four times the length of the printing elements 80, or approximately 40 mils. The width of the areas 154, 156 and 158 is selected such that the areas 154, 156 and 158 can be readily distinguished from the narrower areas separating the slots 148, 150 and 152, and although in the embodiment illustrated in FIG. 7, the widened areas 154, 156 and 158 have been selected to be approximately twice as wide as the areas separating the slots 148, 150 and 152, other widths may be used.
In operation, when the labeler is not printing a label, one of the home position defining indices, for example, the aperture 142 is aligned with the detector 50. When the trigger switch 44 (or other manually operable switch) is depressed, the microprocessor 42 (FIG. 6) issues a start motor command to the control processor 130 which in turn renders the motor drive/brake circuit 134 operative to energize the motor 48. The light-emitting diode 138 is also enabled. When the motor 48 is energized, the timing disc 51 is rotated in the direction shown by the arrows in FIGS. 6 and 7. As the motor rotates, any slack present in the web 18 and any backlash in any of the web advancing mechanism is taken up while a portion of the aperture 142 is still aligned with the detector 50. The motor 48 continues to rotate until the trailing edge of the aperture 142 is detected by the detector 50. At this point, all slack in the system has been taken up and the motor 48 is up to operating speed.
When the trailing edge of the aperture 142 is detected by the detector 50, the amplitude of the signal applied by the photodetector 140 to the control processor 130 changes. The control processor 130 responds to this change by issuing a start print command to the microprocessor 42. The start print signal indicates to the microprocessor 42 that the motor is up to speed and the web is positioned to accept printing at the printing positions defined by the selected print format.
As the motor 48 continues to rotate, the transitions between the slots 148 and the opaque areas disposed therebetween are detected by the photodetector 140, and signals repreSentative of the transitions are applied to the control processor 130. The control processor 130 responds to the transitions and generates a position pulse signal and applies it to the microprocessor 42 each time a transition occurs. The position signals are counted by the microprocessor 42 in order to determine the position of the label with respect to the print head 66. When the print head 66 is positioned over a print area on the label, as defined, for example, by the print format, the entered data is printed on the labels 16. The process continues with the microprocessor 42 receiving position pulse signals from the control processor 130 until the entered data is printed on one or more print areas of the labels 16.
As the printing process continues, the timing disc 51 continues to rotate until the warning track defined by the widened area 154 is detected. The widened area 154 is detected by the control processor 130 when the length of time that an opaque area is being detected by the photodetector 140 exceeds the length of time between the transition pulses generated by the slots 148 by a predetermined amount. Once it has been determined that a warning track such as the area 154 has been detected, the microprocessor is conditioned to respond to the next transition by rendering the motor drive/brake circuit 134 operative to brake the motor 48. Thus, when the leading edge of the aperture 144 is detected, a brake signal is applied to the motor drive/brake circuit 134 tO cause the motor drive/brake circuit 134 to shunt the armature winding of the motor 48 to thereby dynamically brake the motor 48. The motor 48 continues to coast for a short distance until the aperture 144 is aligned with the detector 50, and the printing process is terminated. If it is desired to print another label, the trigger switch 44 is again depressed and another label is printed as the disc 51 is advanced until the aperture 146 is aligned with the detector 50.
Also, although the timing disc 51 is shown in conjunction with a motor driven advancing mechanism, it may also be used in conjunction with a hand or manually operated advancing mechanism. In such an event, even though the signals provided by the timing disc 51 would not be used to control a motor, the position signals would still be used to indicate to the microprocessor when a printable area is beneath the print head, and cause printing to be initiated when such an area is present.
As previously stated, the timing disc 51 provides very accurate information defining the position of the web. However, in order to make use of the accurate position signals provided by the timing disc 51, it is necessary to compensate for manufacturing tolerances present in the web advancing mechanism and in the positioning of the print head 66. Consequently, in accordance with another aspect of the present invention, there is provided a way to alter the angular position of the timing disc 51 with respect to the angular position of the web advancing wheel 49. Various other keying means could be used to affix the disc 51 to the shaft. For example, a slot could be provided on the shaft, and slot engaging members could be provided on the disc. Alternatively, the shaft could be provided with a plurality of keys or keyslots, and the disc 51 provided with a single keyslot or slot engaging member. Other variations could be used. In the illustrated embodiment, this is accomplished by mounting the timing disc 51 on a keyed shaft and providing a plurality of offset keyslots on the disc 51. Each of the offset keyslots is associated with one of the home position indices 142, 144 and 146 and is offset therefrom by the amount of adjustment required. Thus, any required adjustment may be obtained by positioning the appropriate slot on the key of the shaft.
For example, in the timing disc illustrated in FIG. 7, three keyways captioned 1, 2 and 3 are shown. The angular displacement between the keyways 1 and 3 is nominally 122°, while the angular displacement between the keyways 1 and 2, and 2 and 3 is nominally 119°. This compares with a 120° angular displacement between the leading edges of the apertures 142, 144 and 146, and permits a ±1° adjustment of the disc 51 relative to the web advancing wheel 49 and the detector 50.
If for example, the keyway designated by the numeral 1 were keyed to the shaft 141 by a key 160, the trailing edge of the aperture 142 will lead the center line of the key 160 by approximately 2°. The 2° offset shall be called the minus 1° position. If the keyway captioned by the numeral 3 is keyed to the key 160, because the keyways 1 and 3 are spaced by 122°, the trailing edge of the aperture 144 will lead the center of the key 160 by 4°, thus resulting in a positive 2° shift in the position of the positioning slots with respect to the minus 1° position. Adding 2° to minus 1° results in positive 1°, so this position can be considered the plus 1° position. If the keyway captioned by the numeral 2 is keyed to the key 160, the disc 51 will have been rotated a total of 122° plus 119° or 241 ° relative to its position when keyed to keyway number 1, thus resulting in a positive 1° shift in the position of the positioning slots relative to the minus 1° position. Thus, this position becomes the zero degree position, and positive and negative 1 degree adjustments of the disc 51 relative to the zero degree position may be readily attained. Other adjustments may be achieved by altering offsets between the keyways 1, 2 and 3. For example, a ±2° adjustment by spacing the keyway captioned 3 by 124° from the keyway captioned 1, and by spacing the keyway captioned 2 by 118° from the keyways captioned 1 and 3. In general, any offset may be achieved by appropriately. spacing the keyways 1 and 3 by the total desired positive and negative offset added to 120°. If equal positive and negative offsets are desired, such equal positive and negative offsets may be achieved by dividing the remainder of the 360° are between the keyways captioned Z and the keyways captioned 1 and 3.
Although various types of motors, including stepping motors, are usable as the web advancing motor 48, it has been found that a D.C. motor is particularly useful as the web advancing motor 48, partly because of its good low speed torque characteristics. However, when a D.C. motor is used, it is necessary to provide circuitry for controlling the speed of the motor shaft. In the present embodiment, the motor speed control is provided by the control processor 130. As previously discussed, the control processor 130 receives signals representative of the back EMF generated by the motor 48 when it is coasting, and adjusts the drive signal applied to the motor 48 to thereby maintain the speed of the motor 48 substantially constant.
Referring to FIG. 8, the motor 48 is driven by the motor drive/brake circuit 134 which includes a transistor drive circuit 170 that applies an energizing potential to the motor 48 when a run signal is received from the control processor 130. An interlock circuit prevents both the run and brake signals from being applied to the drive/brake circuit 134 simultaneously in the event of a microprocessor or other malfunction. The motor drive/brake circuit 134 also includes a dynamic braking circuit 172 that shunts the armature of the motor 48 to provide dynamic braking when a brake signal is received from the control processor 130. A comparator 174 is connected to the motor 48 and serves to compare the back EMF generated by the motor 48 when it is coasting with a reference voltage. A sampling gate 176 couples the output of the comparator 174 to the control processor 130.
The run signal applied to the drive circuit 170 includes a series of pulses which cause the drive circuit 170 to energize the motor 48 at periodic intervals. The back EMF generated by the motor 48 between drive pulses is sampled by the comparator 174 and the sampling gate 176, which operate as an analog-to-digital converter, to indicate to the control processor 130 whether the back EMF generated by the motor 48 is greater than or less than the reference voltage applied to the comparator 174. If the back EMF is less than the reference voltage, the next run pulse is generated by the control processor 130 again to energize the motor 48. If the back EMF generated by the motor 48 is greater than the reference voltage, indicating that the speed of the motor is excessive, the next run pulse is eliminated, and the motor is allowed to coast. During the coasting period the back EMF is measured at periodic intervals until it drops below the reference voltage, at which point another run pulse is generated. The speed of the motor may be adjusted by adjusting the reference voltage.
The run pulse generation and back EMF sampling is illustrated in greater detail in FIG. 9. Referring to FIG. 9, the back EMF is sampled during a first sampling period 179 occurring during a portion of the time interval ranging from zero to T. If the back EMF is less than the reference a run pulse, as illustrated by the pulse 180 is generated during the time interVal between T and 2T. The duration of the pulse 180 is controlled by the clock (not shown) in the control processor 130, and is preferably on the order of 500 microseconds to 1 millisecond. No sample is taken during the time interval between T and 2T because such a sample would be meaningless because all that would be measured would be the amplitude of the pulse 180.
After the run pulse 180 has been terminated at the time 2T, the drive to the motor 48 is also terminated; however, the termination of the drive to the motor 48 results in a transient across the armature winding of the motor 48. Consequently, the voltage across the motor 48 is not immediately sampled because it is not representative of the back EMF being generated by the motor. Instead, the sampling is delayed until a sampling period 182 that follows the time 2T by a time interval sufficient to allow the transient to die down. It has been determined that delaying the sampling period 182 for approximately 300 microseconds following the termination of a run pulse allows enough of the transient to die down to permit an accurate reading of the back EMF of the motor 48 to be made; however, the delay time is dependent on the size and inductance of the motor, as well as other factors, and other values may be used depending on the particular components used. The sampling is done under the control of the sampling gate 176 which is enabled during the sampling period 182 and other sampling periods by the microprocessor 130.
If the back EMF measured during the sampling period 182 is too low, another run pulse 184 is generated during the time interval between 3T and 4T, and the back EMF is again sampled during a sampling period 186 occurring prior to the time 5T. If the back EMF during the sampling period 186 is again too low, another run pulse will be generated at time 5T; however, if the back EMF is higher than the reference voltage, no run pulse will be generated at time 5T, as is illustrated in FIG. 9. Rather, the back EMF will be sampled during a subsequent sampling interval 188 prior to the time 6T, and if the back EMF has dropped below the reference voltage, another run pulse 190 will be generated at the time 6T. The process will be repeated at periodic intervals with the run pulses being eliminated as required to maintain the speed of the motor 48 substantially constant.
Referring now to FIG. 10. When the labeler is initially energized, the parameters in the microprocessor 42 and the control processor 46 are initialized, and the control processor 46 is conditioned to initiate the feeding of the web upon receipt of a start pulse from the microprocessor 42. Upon receipt of a start pulse, a clock in the control processor 46 is reset to zero. Subsequently, a separate timer is updated to indicate how many times the control processor clock has been reset. This provides an indication of how long the motor 48 has been running. If the time exceeds a predetermined limit, the run timer times out, the motor is stopped and braked, and the control processor 46 is conditioned to await the next start pulse. A signal may also be sent to the audio alarm 52 to indicate a jam. If no timeout occurs, the detector 50 is sampled to determine whether a start print edge (first opaque edge after home position aperture, FIG. 7) has been encountered. If the edge has been detected, a start print pulse is sent to the microprocessor 42, and the condition of the motor is checked, as is described later. If the edge passed previously, the timing disc is checked for a position index. If a position index is detected, a position pulse is sent to the microprocessor 42. If no index is detected, the timing disc is checked for the presence of the warning track (widened opaque area, FIG. 7). The widened area can be readily determined by the length of time it is aligned with the sensor 50. When the end of the warning track is detected, the motor is stopped, the brake is turned on for a predetermined time interval, and the control processor is conditioned to await the next start motor command.
The purpose of the above-described steps is to determine the position of the timing disc, and hence the position of the label during the printing cycle. In addition to determining the position of the label, the speed of the motor must be determined. In the logic diagram illustrated in FIG. 10, the motor speed check is made subsequent to each position check. Thus, if the run timer has not timed out, and the end of the warning track has not yet been detected, a motor speed check is made. This is accomplished by first checking the motor to see if it is on or off. If the motor is off, the system waits until a sampling period is reached. When the sampling period is reached, the back EMF is checked to determine motor speed. The result of the check, indicating whether the motor speed is too fast or too slow, is stored. If the motor is on, no speed check can be made, and the motor is turned off.
After the back EMF has been checked, or after the motor has been turned off, the system waits for the processor clock to reach time ΔT, that is, the next time at which a run pulse can be generated. When the time ΔT is reached, the stored result is checked to determine whether the motor speed was too slow. If the motor speed had been too slow, the motor is turned on, the control processor clock is reset to zero, the run time is updated to include the time accumulated by the processor clock during the last cycle, and the cycle is repeated. If the speed of the motor was not too slow, the motor is not turned on before the processor clock is reset to zero and the run timer updated. In the event that the motor was previously on, and no back EMF check was made and stored, it is assumed that the motor speed was not too slow, and the processor clock is reset to zero without turning on the motor. Because the motor is now off, a speed check can be readily made during the next cycle.
As previously discussed, the labeler according to the invention is a hand-held labeler that is powered by a battery. As in the case of all battery-powered devices, the voltage applied to the various circuits drops as the battery discharges, and may even reach zero when the battery is completely discharged or is removed. Such voltage variations can cause serious problems. For example, when the voltage applied to a microprocessor drops below a predetermined level, the operation of the microprocessor becomes erratic. When this occurs, the erratic signals from the microprocessor can alter or erase the data stored in the various memories. The processor can also cause damage to the print head, for example, by continuously energizing one or more of the printing elements. In addition, when a non-volatile RAM, such as the NVRAM 60, is used, a drop or loss of battery voltage can cause the data stored in the NVRAM to be lost.
Thus, in accordance with another aspect of the present invention, there is provided a circuit (FIG. 11) that monitors the voltage produced by the main battery, such as, the battery 26, and protects the various memories and the print head in the event of a low battery condition, and in the event that the battery is removed. This is accomplished by a comparator 200 that compares the voltage at the battery 26 with a low battery voltage reference. In the event that the voltage provided by the battery 26 drops below the low battery reference potential, the comparator 200 applies a signal to the microprocessor 42 and to the control processor 46 in order to put the processors in a reset condition to prevent erratic operation thereof. In addition, the comparator 200 applies a disabling signal to the RAM 58 and the NVRAM 60 to prevent data from being written onto or erased from the RAMs. A disabling signal is also applied to the print head 64 to clamp the print head driver 68 to thereby prevent energization of the print head 66. Thus, the RAMs and the print head are effectively protected from erratic operation of the microprocessors.
In order to prevent the loss of data from a non-volatile read-only memory such as the NVRAM 60, a back-up battery, such as, for example, a lithium battery 210 (FIG. 12), is provided. The use of a lithium battery for such a purpose is particularly advantageous because such batteries have a relatively long shelf life, on the order of approximately ten years. However, if the lithium battery were used to power the NVRAM for extended periods of time, it would become discharged relatively rapidly. Therefore, some means must be provided to prevent the back-up battery 210 from discharging prematurely. Thus, when the labeler is turned on, the NVRAM 60 is powered from the main battery, such as the battery 26; however, some provision must be provided to power the NVRAM 60 when the labeler is stored in an off condition for an extended period of time.
In the hand-held labeler according to the invention, the labeler circuits are powered by the battery 26 which is connected to a voltage regulator 212 via an on-off switch 214 (both not shown in FIG. 2). The regulator 212 provides a regulated voltage, for example, 5.6 volts, to the labeler circuits whenever the on-off switch 214 is closed. Under these conditions, the output voltage of the regulator 212 is applied to the NVRAM 60 by means of a blocking diode 216, and the NVRAM 60 is powered by the battery 26 via the switch 214, the regulator 212 and the diode 216 whenever the labeler is operating. A diode 211 isolates the battery 210 from the rest of the circuitry under these conditions because the voltage applied to the NVRAM 60 is higher than the voltage of the battery 210, and the diode 211 is reverse biased.
When the labeler is turned off, the output voltage of the regulator 212 is zero, and consequently, if the labeler is stored for an appreciable length of time, the back-up battery 210 will eventually discharge if the regulator 212 were relied on to power the NVRAM 60. Therefore, in accordance with another important aspect of the present invention, there is provided an auxiliary circuit that powers the NVRAM 60 even when the labeler is off. The auxiliary circuit includes a Zener diode 218 that is coupled to the battery side of the switch 214 by a resistor 220. The junction of the resistor 220 and the Zener diode 218 is coupled to the NVRAM 60 by another blocking diode 222. Thus, when the switch 214 is open, the NVRAM 60 is powered by the auxiliary circuit. As in the case when the switch 214 is on, the diode 211 isolates the battery 210 from the rest of the circuitry as long as the battery 26 is present and active. By making the voltage of the Zener diode 218 lower than the output voltage of the regulator 212, for example, 4.2 volts, interaction between the two circuits is eliminated. For example, when the switch 214 is closed, the voltage appearing at the cathode of the blocking diode 222 is greater than the voltage appearing at its anode. This reverse biases the diode 222 and prevents currents from flowing from the regulator 212 into the Zener diode 218 and discharging the battery 26. When the switch 214 is open, the blocking diode 216 is reverse biased, thus preventing the labeler circuitry from discharging the batteries 26 and 210. If the battery 26 is removed, or becomes discharged, the diode 211 becomes forward biased and the NVRAM 60 is powered by the battery 211. Under these conditions, the diodes 216 and 222 isolate the battery 211 from all of the labeler circuitry other than the NVRAM 60.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described above.
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Circuitry including a first and second source of electrical energy provides a continuous supply of electrical energy to a volatile memory circuit utilized within an electrical apparatus. The circuitry includes an on and off switch and allows for the first source of electrical energy to be supplied to the volatile memory when the switch is both in an on and off position. The secondary source of electrical energy is only used to supply electrical energy to the volatile memory when the first souce of electrical energy is either inoperative or disconnected from the circuit. Such circuitry allows for conservation of power of the second source of electrical energy which in some electronic apparatus may include a lithium battery that may be relatively difficult to replace.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to micro-fibers-generating conjugate fibers. More particularly it relates to micro-fibers-generating conjugate fibers from which micro-fibers are generated by removing a part of components constituting the conjugate fibers, and a woven fabric or non-woven fabric using the same.
2. Description of the Related Art
Recently, as high-class and diversified clothes have been desired, improvement in feeling of fibers by way of making fibers very fine has been attempted, and further as use applications of synthetic paper, non-woven fabric, etc. are developed, a process for producing micro-fibers has been also desired to be developed. Among micro-fibers-generating fibers, those of the so-called island-in-sea type fibers are very useful and it is well-known that a number of products using the same are commercially available.
Among the island-in-sea type, micro-fibers-generating fibers, particularly those wherein the island-in-sea structure is relied on a polymer blend, as disclosed in Japanese patent publication No. Sho 47-37648/1972, are prepared by blending different kinds of polymers constituting the respective components of island and sea, melt-spinning the resulting blend and removing the sea component with a solvent to leave only the island component. In such fibers, the blending proportion of the sea component should be large for keeping the independency of the island component. However, the sea component is used for temporarily binding a bundle of micro-fibers, and is to be finally removed. Hence the binding component cannot be a reinforcing component. So, the micro-fibers-generating fibers of this type could not have a high tenacity. Further, the bundle of micro-fibers as a remaining island component obtained by removing the sea component from the island-in-sea type micro-fibers-generating fibers has a low tenacity.
Further, as to the spinnability of fibers obtained by subjecting different kinds of polymers to composite spinning so as to give an island-in-sea structure as disclosed in Japanese patent application laid-open No. Sho 60-21904(1985), since the spinnability of the sea component is very often inferior, the spinnability of the island-in-sea type fibers is inferior, too. Further, in the case of fibers the island-in-sea components of which are of a polymer blend, since polymers having different properties from each other are blended, a satisfactory spinning stability cannot be obtained. So, the polymer is extruded from spinning nozzles in a thick and fine form and the extrudate is liable to break like raindrops.
SUMMARY OF THE INVENTION
The object of the present invention is to provide micro-fibers-generating fibers having a tenacity enough for practical uses, and a stabilized spinnability.
The present inventor has made extensive research in order to solve the above-mentioned problems of micro-fibers-generating fibers, and as a result has found that when micro-fibers-generating fibers are composed of conjugate fibers; at least one of the conjugate components of the conjugate fibers has an island-in-sea structure and is exposed on the surface of the fibers; the island component of the structure constitutes micro-fibers of 0.1 denier or less; and the other composite components constitute fibers of 0.5 denier or larger, and micro-fibers of 0.1 denier or less consisting of the island component are generated in the vicinity of the fibers of 0.5 denier or larger after removing the sea structure of the island-in-sea component, thereby exhibiting a high tenacity due to the fibers of the other components as well as a specific feeling of micro-fibers.
The present invention has the following features.
(1) Micro-fibers-generating conjugate fibers, wherein at least one conjugate component of said fibers has an island-in-sea structure, said micro-fibers-generating conjugate fibers has a fineness of one denier or more, preferably 2-10 denier, the other conjugate component of said micro-fibers-generating fibers has a fineness of 0.5 denier or more, preferably 1-5 denier, said at least one conjugate component having an island-in-sea structure is exposed on the surface of said microfibers-generating fibers, the sea part of said conjugate component is removable by a solvent treatment, the island part of said conjugate component after removing the sea part has a fineness of 0.1 denier or less, preferably 0.1-0.0001 denier.
(2) A woven or non-woven fabric having micro-fibers obtained from a woven or non-woven fabric prepared by using micro-fibers-generating conjugate fibers as set forth in
(1), by removing the sea part contained in said conjugate fibers:
(3) A woven or non-woven fabric having micro-fibers obtained from a woven or non-woven fabric prepared by using micro-fibers-generating conjugate fibers as set forth in (1) and hot-melt adhesive fibers, by removing the sea part contained therein, before or after subjecting said woven fabric or non-woven fabric to hot-melt adhesive treatment:
(4) A woven or non-woven fabric obtained from a woven or non-woven fabric prepared by applying a binder to the (1), by removing the sea part contained therein.
(5) Conjugate micro-fibers obtained by removing the sea part of the conjugate component of the micro-fibers-generating generating conjugate fibers as set forth in (1).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-section of micro-fibers-generating conjugate fibers of side-by-side type.
FIG. 2 shows a cross-section of micro-fibers-generating conjugate fibers of sheath-and-core type.
In these figures, numeral 1 represents one conjugate component, 2 represents island part, 3 represents sea part and 4 represents the other conjugate component.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The configuration of the conjugate fibers in the present invention has no particular limitation as far as the component having an island-in-sea structure as a component generating micro-fibers is exposed on the surface of the conjugate fibers. Examples of such conjugate fibers are shown in FIGS. 1 and 2. Referring to FIG. 1, one component 1 and the other component 4 constitute a side-by-side type conjugate fiber. The component 1 has an island-in-sea structure. In FIG. 2, a sheath component 1 and a core component 4 constitute a sheath-and-core type conjugate fiber. In these figures, the island-in-sea structure consists of a sea part 3 and an island part 2.
Examples of resins usable as the island part 2 and the above other component 4 are polyolefins such as polyethylene, polypropylene, etc., polyamides such as nylon 6, nylon 66, etc. and thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, etc. Further, examples of resins usable as the sea part 3 are those which are removable without having a bad effect upon the island part or components other than the sea part, such as partially saponified polyvinyl alcohol (water-soluble), copoly(ethylene-terephthalate-5-sodium sulfoisophthalate) hydrolyzable with alkaline, etc.
As a solvent for removing the sea part, water, preferably a hot water, alkaline water are exemplified.
As a process for producing micro-fibers-generating conjugate fibers, any conventional process for spinning a conjugate fiber of sheath-core type or side-by-side type may be employed, provided that at least one of the conjugate components of the fiber has an island-in-sea structure and is exposed on the surface of the conjugate micro-fibers-generating fiber. The other conjugate component of the fiber has a normal structure. For obtaining the island-in-sea structure, a process of subjecting both the polymers for island and sea parts to blending, as disclosed in Japanese patent publication No. Sho 47-37648/1972, a process of dividing one component flow of resin into a plurality of flows and combining the flows with the other component flow of resin to form a conjugate flow of resin to a spinneret, as disclosed in Japanese patent application laid-open No. Sho 60-21904/1985, etc. are exemplified.
After spinning of micro-fibers-generating conjugate fibers, they are subjected to a woven or non-woven fabric processing. The fibers may be drawned at a proper ratio to increase the tenacity thereof before the processing. As a woven or non-woven fabric processing, any conventional processes may be employed such as a spunbonding process, a meltblowing process, a needlepunching process, a stitchbonding process, a spunlacing process, a paper machine process, a woven machine process, etc.
A step of removing the sea part of the conjugate components of the fibers may be carried out either in the form of micro-fibers-generating conjugate fibers or in the form of a woven or non-woven fabric consisting of the fibers.
The present invention will be described in more detail by way of Examples, but it should not be construed to be limited thereto.
EXAMPLE 1
A blend of a thermoplastic polyvinyl alcohol (polymerization degree 400; saponification degree 62%) with a polypropylene (MFR (melt flow rate)=10) in a ratio by weight of 3:2 as an island-in-sea component and a high density polyethylene (MI (melt index)=30) as the other component were each fed into a spinneret of side-by-side type having spinning holes of 0.4 mm in diameter (the total number of the spinning holes: 198) at a rate of 100 g/min., and extrudated from the spinneret at a spinning temperature of 210° C., followed by drawing of the extruded fibers according to spunbonding process at a rate of 500 m/min. to obtain a fleece of micro-fibers-generating conjugate fibers of side-by-side type.
The resulting fleece was subjected to water needle punching to simultaneously carry out removal of the sea component and interlacing the fibers, whereby a non-woven fabric of micro-fibers (basis weight 60 g/m 2 ). The resulting non-woven fabric was observed by a microscope, and the micro-fibers having a fineness of 0.0001 to 0.1 denier and normal-fibers having a fineness of 3 denier were observed.
The non-woven fabric had a tensile break strength of 0.12 kg per test piece of 5 cm wide and 10 cm in length (in the mechanical direction).
EXAMPLE 2
A blend of a thermoplastic polyvinyl alcohol (polymerization degree: 400 and saponification degree: 62%) with a polypropylene (MFR=20) in a ratio by weight of 1:1, as a sheath component resin, at a rate of 100 g/min., and a polypropylene (MFR=40) as a core component resin, at a rate of 50 g/min., were each fed into a spinneret having circular spinning holes of 0.6 mm in diameter, followed by extrudation from the spinneret at a spinning temperature of 240° C. and drawing at a rate of 428 m/min. to obtain microfibers-generating conjugate fibers of sheath-and-core type. The cross-section of the resulting unstretched fibers was observed by a microscope and the component having an island-in-sea structure was observed to be present surrounding the core component having a fineness of 3 denier, the number of islands being several hundreds.
The resulting micro-fibers-generating conjugate fibers were stretched to three times the original length to obtain drawned micro-fibers-generating conjugate fibers. The drawned fibers had a tensile break strength of 0.5 g/d. Further, staple fibers obtained by cutting the above fibers into those of 51 mm long were blended with hot-melt adhesive conjugate fibers (sheath component: polyethylene, and core component: polypropylene) (2 d, 51 mm) in a ratio by weight of 1:1, followed by carding of the blended fibers, to form a web. The resulting web was subjected to a heat treatment by means of emboss rolls heated at 130° C. to obtain a non-woven fabric. After washing with hot water at 80° C., a non-woven fabric of polypropylene fibers having a fineness of 0.0002 to 0.1 denier and a basis weight of 50 g/m 2 was obtained. The non-woven fabric had a break strength of 7.3 kg per test piece of 5 cm wide and 10 cm in length (in the machine direction).
EXAMPLE 3
The staple fibers of the micro-fibers-generating conjugate fibers obtained in Example 2 were carded into a web, followed by subjecting the web to water-needlepunching, simultaneously removing the sea component and interlacing the fibers, coating the resulting web with an acrylic resin emulsion and impregnate the emulsion with the web and drying to obtain a non-woven fabric containing micro-fibers of polypropylene having a fineness of 0.0002 to 0.1 denier and normal-fiber having a fineness of 3 denier, and having a basis weight of 150 g/m 2 . This non-woven fabric had a break strength of 3.3 kg per test piece of 5 cm wide and 10 cm in length (in the machine direction).
EXAMPLE 4
By passing the stretched fibers obtained in Example 2, though a hot water tank, the sea component was removed to obtain a fiber bundle comprising micro-fibers of polypropylene fibers of 0.0002 to 0.1 denier and normal-fibers of 3 denier. The break strength of the fiber bundle was 1 g/d.
EXAMPLE 5
A blend of carboxylic acid-modified thermoplastic polyvinyl alcohol (polymerization degree: 300 and saponification degree: 62%) with a polypropylene (MFR=20) in a blending ratio by weight of 1:1 as a sheath component resin and a polypropylene (MFR=20) as a core component resin were each fed into a spinneret having circular spinning holes of 1.0 mm in diameter (the total number of spinning holes: 240) at a rate of 100 g/min. at a spinning temperature of 240° C., extruded through the spinning holes, and drawned at a rate of 428 m/min. to obtain composite micro-fibers-generating fibers of sheath-and-core type. The cross-section of the undrawned fibers was observed by a microscope. As a result, the sheath component having an island-in-sea structure was present surrounding the core component, the number of the islands being several hundreds.
The resulting micro-fibers-generating conjugate fibers were drawned to four times the original length to obtain drawned micro-fibers-generating conjugate fibers. Further, the fibers were cut into those of 3 mm, followed by subjecting them to wet paper processing to obtain a non-woven fabric of micro-fibers of polypropylene of 0.02 to 0.1 denier and normal-fiber of 2.2 denier, and having a basis weight of 100 g/m 2 . The resulting non-woven fabric had a break strength of about 0.8 kg per test piece of 5 cm wide and 10 cm in length.
The micro-fibers-generating conjugate fibers of the present invention comprise a part having an island-in-sea structure, which generates micro-fibers of 0.1 denier or less, and the other part which generates fibers of 0.5 denier or more; hence the fibers have a high break strength as micro-fibers-generating fibers. Thus, a sufficient tenacity of the fibers for practical use is obtained. Further, in the aspect of production, too, as compared with the case where spinning is carried out with only a component having an island-in-sea structure, a broader range of spinning conditions and a stabilized spinnability are obtained by subjecting the component having the island-in-sea structure to conjugate-spinning with the other component having good spinning properties.
Further, a woven or non-woven fabric comprising micro-fibers obtained from the micro-fibers-generating conjugate fibers has a high strength, a toughness, and a specific feeling, since the micro-fibers of 0.1 denier or less follow about or supported by a fiber of 0.5 denier or more.
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Micro-fibers-generating conjugate fibers having a practically sufficient tenacity, a broad tolerance of spinning conditions and a stabilized spinnability, and a woven fabric or non-woven fabric prepared from the same are provided, which micro-fibers-generating conjugate fibers comprises one conjugate component of island-in-sea structure and the other conjugate component of a normal structure, the former component being exposed on the surface of the conjugate fiber and the sea part of the island-in-sea structure being removed by a solvent treatment at a later stage after or before forming into a woven or non-woven fabric to generate micro-fibers along with the fibers of the other component.
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BACKGROUND OF THE INVENTION
The present invention relates to a water ejecting gun, and more particularly to a water ejecting gun which can extinguish a fire with the least amount of water while reducing the damage to interiors caused by the ejected water.
Conventionally, fire extinguishing nozzles or guns used for extinguishing fire in various buildings including sky-scrapers usually eject at least 550 liters per minute of water. This tremendous amount of ejected water intrudes not only the room under fire but also many other rooms located below the room under fire, and causes heavy or serious damage to buildings, interiors, clothing, furniture and the like.
Therefore, a fire-extinguishing apparatus which can reduce such damage caused by the ejected water has been clamored for many years.
Accordingly, it is an object of the present invention to provide a water ejecting gun which can enhance the fire extinguishing efficiency while drastically reducing the damage caused by the ejected water.
SUMMARY OF THE INVENTION
In summary, the present invention discloses a water ejecting gun which comprises a mechanism for producing two kinds of ejecting flows which consist of a straight flow and a spray flow wherein the straight flow is ejected from an ejecting opening maintaining a constant small ejected flow area, while the spray flow is ejected from the same ejecting opening expanding radially after being ejected.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view partially broken away of a first embodiment of the water ejecting gun of the present invention.
FIG. 2 is a partial plan view of the water ejecting gun of FIG. 1.
FIG. 3 is a cross sectional view of the water ejecting gun taken along the line I--I of FIG. 1.
FIG. 4 is a cross sectional view of the water ejecting gun taken along the line II--II of FIG. 1.
FIG. 5 is a cross sectional view of the water ejecting gun taken along the line III--III of FIG. 1.
FIG. 6 is a schematic view of a part of the water ejecting gun showing the relationship between the nozzle and the core element of the water ejecting gun.
FIG. 7 is a front view partially broken away of a second embodiment of the water ejecting gun of the present invention.
FIG. 8 is an enlarged partial front view of the water ejecting gun of FIG. 7 at a position producing a spray flow.
FIG. 9 is an enlarged partial front view of the water ejecting gun of FIG. 7 at a position producing a straight flow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in detail hereinafter in conjunction with preferred embodiments.
(First Embodiment)
This embodiment relates to a water ejecting gun which can eject a straight water flow and a spray water flow simultaneously.
In FIG. 1, a water ejecting gun A comprises a gun body 1, an adaptor 2, an ejecting flow forming portion 3 and a head fitting 4, wherein the gun body 1 and the ejecting flow forming portion 3 are connected by the adaptor 2 and the head fitting 4 for regulating the ejecting flow is threadedly engaged with the front extremity of the ejecting flor forming portion 3.
The gun body 1 is formed like a pistol and comprises a horizontal barrel sleeve 5 and a slanted stock sleeve 6 which has the upper end thereof integrally connected to the rear portion of the horizontal barrel sleeve 5.
A swivel joint 7 for rotatably connecting a water supply hose (not shown in the drawings) to the stock sleeve 6 is mounted on the lower end of the stock sleeve 6.
A cylinder 8 is threadedly mounted on the rear end of the horizontal barrel sleeve 5 and a piston rod 9 is slidably disposed in the cylinder 8.
The cylinder 8 has an inner wall portion 8a at the inner end thereof and has an end plate 11 threadedly mounted on the outer end thereof, thus defining a spring loading chamber between the inner wall 8a and the end plate 11.
A spring 12 is disposed in the above spring loading chamber so as to bias the piston rod 9 in a direction toward the front end of the horizontal barrel sleeve 5.
A valve element 13 is threadedly mounted on the front extremity of the piston rod 9.
To the inside of the front portion of the horizontal barrel sleeve 5, a hollow intermediate sleeve 14 is fixedly mounted and a teflon seat 14a is attached to the proximal end of the intermediate sleeve 14.
The above valve element 13 rests on the teflon seat 14a.
A trigger 15 has the upper ends thereof pivotally connected to the both sides of the horizontal barrel sleeve 5 by fastening bolts 16, while a U-shaped connecting frame 16a has one end thereof connected to the upper portion of the trigger 15 and another end connected to the protruded end of the piston rod 9 (FIG. 2 and FIG. 3).
Due to such construction, when the trigger 15 is pulled or returned, the piston rod 9 moves axially in either a front or backward direction so as to make the valve element 13 contact with or separate from the teflon seat 14a of the intermediate sleeve 14. Accordingly, the water flow from the stock sleeve 6 to the ejecting water forming portion 3 can be allowed or stopped by a simple manipulation of the trigger 15.
Referring to other elements mounted on the gun body 1, numeral 17 indicates a cap nut, numeral 18 indicates a trigger retaining ring, numeral 19 indicates an L-shaped trigger cover which has one end connected to the adaptor 2 and another end connected to the lower end of the stock sleeve 6, thus enclosing the trigger 15, and 20 indicates a pair of gun-protective plates attached to both sides of the horizontal barrel sleeve 5.
Referring now to the ejecting flow forming portion 3, the portion 3 comprises an inner sleeve 21 which has the rear end thereof mounted on the front end of the adaptor 2, an outer sleeve 22 which is rotatably and axially-movably mounted on the outer surface of the inner sleeve 21 and a nozzle element 23 concentrically disposed in the inner sleeve 21 by way of a bridge element 29 (FIG. 4 to FIG. 6).
The inner sleeve 21 is provided with an outer thread 24 on the outer surface of the front end thereof with which the head fitting 4 is meshed.
The inner sleeve 21 is also provided with elongated holes 25 which extend in an axial direction.
On the outer surface of the outer sleeve 22, a rubber-made protective cover 26 is mounted.
Guide bolts 27 pass through the elongated holes 25 and integrally connect the outer sleeve 22 with nozzle element 23 by way of the bridge 29.
Accordingly, when the outer sleeve 22 is rotated relative to the inner sleeve, the outer sleeve 22 moves in an axial direction due to the thread engagement with the inner sleeve 21 and simulaneously moves the guide bolts 27 and the elongated nozzle element 23 in the same axial direction.
The nozzle element 23 has both ends thereof open-ended and defines a straight main flow passage 28 therein.
The main flow passage 28 has the proximal end 28a thereof radially enlarged and another remaining portion including the distal end squeezed.
The bridge 29 disposed between the inner sleeve 21 and the nozzle element 23 is, as shown in FIG. 4, made of a circular sleeve and a pair of opposed ribs thus defining a pair of fan-shaped sub flow passages 30 therein.
A core element 31 is coaxially disposed in and fixedly attached to the adaptor 2 by a fastening bolt 32.
The front end of the core element 31 is capable of water-tightly coming into contact with the inside of the enlarged portion 28a of the main flow passage 28.
The core element 31 is provided with a radial passage 33 which communicates with the main flow passage 28.
The head fitting 4 is provided with an ejecting opening 34 on the front wall thereof while defining a large circular space behind the front wall.
The head fitting 4 has the proximal end thereof threaded into the other thread portion 24 of the inner sleeve 21 such that the axis of the ejecting opening 34 is aligned with the axis of the main flow passage 28.
In the above mentioned large-circular space defined in the head fitting 4, a rotating fan or agitating element 35 is disposed and is rotatably mounted on the front end of the nozzle element 23.
Thus, the water which passes through the sub flow passage 30 is turned into a spray or atomized by the rotating fan element 35 and subsequently ejected from the ejecting opening 34 of the head fitting 4 in a spray form.
The manner in which the above water-ejecting gun is operated will now be described.
Pressurized water supplied to the stock sleeve 6 of the gun body 1 is filled in the space S1 defined in the horizontal barrel sleeve 5.
When such pressurized water is to be ejected from the ejecting opening 34 of the head fitting 4, the trigger 15 is pulled in a direction of an arrow a.
In this way, the piston rod 9 is moved in a backward direction (direction of arrow b) so that a desired gap is defined between the teflon seat 14a and the valve element 13.
After passing through the above gap, the space S2 in the intermediate sleeve 14 and the adaptor 2, a part of the pressurized water flows into the main flow passage 28 through the flow passage 33 of the core element 31 and is ejected from the ejecting opening 34. Simultaneously, the remaining pressurized water passes through the sub flow passage 30 and is converted into a spray or atomized form and subsequently is ejected from the ejecting opening 34 in spray form.
For adjusting the ratio between the straight flow which passes through the main flow passage 28 of the nozzle element 23 and the spray flow which passes through the sub flow passage 30, the outer sleeve 22 is slid together with the protective cover 26 on and along the inner sleeve 21 so as to adjust the gap defined between the distal end 31a of the core element 31 and the proximal end 28a of the nozzle element 23. Such gap adjustment provides a bypass flow of the pressurized water into the main flow passage 28 through the gap.
Experiment
Utilizing the above water ejecting gun, when water was ejected to an object having a temperature of 800° C. at a rat of 180 liters per minute and under a pressure of 10 kg/cm 2 , the temperature of the object was lowered to 60° C. after 30 seconds.
With the conventional water ejecting gun, even when water is ejected to an object having a temperature of 800° C. at a rate of 350 liters per minute and under a pressure of 6 kg/cm 2 , the temperature was lowered to 60° C. after 60 seconds.
Namely, the water ejecting gun of this embodiment can disperse a water into numerous water particles having the diameter of 0.2 to 0.3 mm. Since each particle has a large surface area, the fire extinguishing efficiency and the adhesion of smoke are greatly enhanced.
Furthermore, for assuring that the ejected water can reach a long distance, the straight water is also ejected along with the above spray water from the ejecting opening 34.
Still furthermore, since the water ejecting gun of this embodiment can be used along with any commercially available fire engines or hoses, no special apparatus or equipment only applicable to the water ejecting gun of the present invention is necessary.
According to this embodiment, the water ejecting gun can extinguish fire with one-third of the water necessary for fire extinguishing operation by the conventional water ejecting gun.
Simultaneously, the water ejecting gun of this embodiment can show a remarkable effect in the fire-extinguishing operation in a closed building structure in terms of lowering the room temperature and the adhesion of the smoke.
Namely, with the provision of the straight nozzle element and the rotary fan element, the water can be ejected by a combination of a straight flow and a sprayed flow so that the water particles contained in the sprayed water can drastically lower the temperature of the fire and enhance the fire extinguishing effect and the adhesion of smoke.
Furthermore, according to this embodiment, a simple manipulation of the trigger provides the ejecting of water as well as the stoppage thereof so that the fire-extinguishing operation can be conducted easily and the damage to interiors caused by the ejected water is also reduced.
(Second Embodiment)
This embodiment is substantially characterized in that the water flow is continuously converted from the spray flow to a straight flow by varying the pulling angle of the trigger.
In FIG. 7, a water ejecting gun B substantially comprises a gun body 50, an ejecting flow forming portion 51 and a head fitting 52.
The gun body 50 comprises a horizontal barrel sleeve 53 and a slanted stock sleeve 54 which has the upper end thereof integrally connected to the rear end of the horizontal barrel sleeve 53.
A slanted stock sleeve 54 is provided with a swivel joint 55 at the bottom end thereof for a hose connection.
In the horizontal barrel sleeve 53, an elongated gun shaft 56 is concentrically and axially-slidably disposed.
Between the inner wall of the horizontal barrel sleeve 53 and the outer surface of the elongated gun shaft 56, a flow passage S3 is defined and this flow passage S3 communicates with the flow passage S4 of the slanted stock sleeve 54.
At the rear end of the horizontal barrel sleeve 53, a spring supporting wall 57 is formed which snugly and slidably supports the gun shaft 56.
The gun shaft 56 is provided with an enlarged diameter portion 58 at a position spaced apart from the above spring supporting wall 57 and defines a spring loading space between the spring supporting wall 57 and the enlarged diameter portion 58. A spring 57a is disposed in the spring loading space.
Due to such construction, the gun shaft 56 is always axially biased in a direction of the front end of the horizontal barrel sleeve 53.
Numeral 59 indicates a trigger which has the upper end thereof pivotally connected to a sleeve 60 which is fixedly mounted on the horizontal barrel sleeve 53 by fastening bolts 60a.
The trigger 59 has a central portion thereof connected by a suitable element (not shown in the drawing) with the gun shaft 56 such that when the trigger 59 is pulled in the direction of an arrow c, the gun shaft 56 moves in the direction of an arrow d.
The trigger 59 is also provided with a stopper plate 61 which can engage a ratchet pawl 62 thereof with a plurality of ratchet teeth 63 formed on an arcuate plate 64 fixedly mounted on the slanted stock sleeve 54.
Due to such engagement, the trigger 59 can be held in any desired pulling angle until the ratchet pawl 62 is disengaged from the ratchet teeth 63.
Referring now to the flow forming portion 51, such portion 51 is substantially made of a sleeve 64 which defines a front squeezed space 66 and a rear enlarged space 67.
FIG. 7 shows the water ejecting gun at a closed position where a valve portion 68 formed on the front end of the gun shaft 56 comes into contact with an inner shoulder portion 69 of the sleeve 65 so that no water is ejected from an ejecting opening 52a formed in the head fitting 52.
Numeral 70 indicates a spiral which is also formed on the front end of the gun shaft 56 spaced spart from the valve portion 68, while numeral 71 indicates a cone formed on the front extremity of the gun shaft 56.
Due to such construction, when the trigger 59 is pulled slightly in the direction c so as to make the gun shaft 56 move slightly in the direction d, as shown in FIG. 8, the valve portion 68 is separated from the shoulder portion 69 forming a gap therebetween which allows the pressurized water to move from the horizontal barrel sleeve 53 to the head fitting 52.
However, since the spiral 70 is still disposed in the front squeezed space of the sleeve 65, the pressurized water which passes through the gap and the squeezed space is agitated or atomized and is ejected from the ejecting opening 52a in a spray form.
When the trigger 59 is further pulled, a part of the pressurized water is atomized by the spiral 70 and is ejected from the ejecting opening 52a in a spray form, while the remaining water is ejected from the same ejecting opening 52a in a straight flow. Namely, the mixture of the spray flow and the straight flow is ejected from the ejecting opening 52a.
When the trigger 59 is completely pulled, the valve portion 68 and the spiral 70 respectively take positions as shown in FIG. 9 so that the flow of the pressurized water is not obstructed by the spiral 70 and only the straight flow is ejected from the ejecting opening 52a of the head fitting 52.
Referring to other elements of the water ejecting gun B of this embodiment, numeral 72 indicates a grip holder mounted on the front portion of the horizontal barrel sleeve 53 for assuring the firm supporting of the water ejecting gun B. Numeral 73 indicates cross-shaped bearings which concentrically and slidably support the gun shaft 56 within the horizontal barrel sleeve 53, while allowing the pressurized water to pass therethrough.
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A water ejecting gun simultaneously produces two kinds of ejecting flows, a straight flow and a spray flow. The gun disposes a rotating or spiral fan element in a water passage for producing the spray flow. The straight flow acts as a carrier for the spray flow. A mechanism for producing the spray and straight flows includes an inner sleeve, an outer sleeve rotatably and axially movable on the inner sleeve, a nozzle element disposed in the inner sleeve which defines a main flow passage and a sub-flow passage and a frusto-conical core element engaging the upstream end of the nozzle element to form a variable gap therebetween. When the gap is open, water flows to the main flow passage. When the gap is closed, a smaller water flow to the main flow passage occurs through radial and axial passages in the core element. The straight and spray water flows exit the gun simultaneously through an ejecting opening. Since the spray flow is made of numerous fine water particles, the flow can efficiently extinguish the fire while reducing damages to interiors ordinarly caused by ejected water.
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FIELD OF THE INVENTION
[0001] This invention relates to wallboard tape. More particularly the present invention relates to wallboard tape wallboard compound adherence beads.
BACKGROUND OF THE INVENTION
[0002] Paper wallboard tape tends to absorb water and soften when applied over thick amounts of compound as is necessary when taping irregular joints and corners. When the paper tape softens, it sags and deforms and a straight line corner is not achieved. Thus, paper tape must be applied over thin layers of compound which requires a number of coats of compound or the imperfections must be pre-filled, increasing labor costs and time to finish. Paper tape does, however, provide good adherence to the compound and provides a good paint surface.
[0003] Wallboard tape made from polyvinyl chloride (“PVC”) is known. While PVC tape provides very straight and durable corner beads and seam joints for wallboard installations, the challenge with PVC is to get a strong adherence of the wallboard compound to the PVC tape.
[0004] One such product, by the inventor of the present invention, is shown in U.S. Pat. No. 5,418,027, issued to John S. Conboy (the '027 patent), the contents of which are incorporated herein by reference. In the '027 patent, a plastic wallboard tape has a raised center section and outwardly extending wing areas having a coating of fibers adhered to both sides. The raised center of the tape is weakened at the top to cause the tape to crease in a straight line when it is folded at an inside or outside corner to define a straight edge at the corner joint. The combination of the rigid water impervious tape and the fibers allows the tape to be applied over imperfectly fitted wallboard joints with large imperfections because the fibers will achieve a mechanical bond with the wallboard compound or other joint materials, allowing a slow cure, and the tape will not be softened by the compound.
[0005] While the invention of the '027 patent greatly improves the adherence of wallboard compound to PVC tape, there is still a need to achieve better adherence of the compound to PVC tape and better acceptance of paint. The present invention achieves this goal.
SUMMARY OF THE INVENTION
[0006] A wallboard tape comprising a paper tape having two outer parallel edges. At least one pair of raised beads are adhered to the tape and extend generally parallel to the outer edges of the tape. The beads may optionally be formed on the tape from a hot melt adhesive and optionally have a generally arcuate top surface. At least one polyvinyl chloride stiffening strip may optionally be adhered to the tape with a hot melt adhesive and a protuberance on the side of the tape opposite the beads and running the length of the tape near the center of the tape also may optionally be applied.
DESCRIPTION OF THE DRAWINGS
[0007] In the accompanying drawings which form part of the specification and wherein like numbers and letters refer to like parts wherever they occur
[0008] FIG. 1 is a fragmentary plan view of a length of wallboard tape according to an embodiment of the present invention;
[0009] FIG. 2 is an end view of a length of wallboard tape according to an embodiment of the present invention;
[0010] FIG. 3 is an enlarged partial end view of a length of wallboard tape according to an embodiment of the present invention;
[0011] FIG. 4 is another enlarged partial end view of a length of wallboard tape according to an embodiment of the present invention;
[0012] FIG. 5 is a fragmentary plan view of a length of wallboard tape according to a second and third embodiment of the present invention;
[0013] FIG. 6 is an end view of a length of wallboard tape according to a second and third embodiment of the present invention;
[0014] FIG. 7 is an enlarged partial end view of a length of wallboard tape according to a second and third embodiment of the present invention;
[0015] FIG. 8 is another enlarged partial end view of a length of wallboard tape according to a second and third embodiment of the present invention;
[0016] FIG. 9 is an end view of a length of wallboard tape applied to a wallboard seam according to a second and third embodiment of the present invention. For clarity, wallboard compound has been omitted from this view;
[0017] FIG. 10 is an end view of a length of wallboard tape according to a variation of the first embodiment of the present invention; and
[0018] FIG. 11 is another enlarged partial vertical sectional view taken along line B-B of FIG. 10 of a length of wallboard tape according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention 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 broad aspect of the invention to the embodiments illustrated. The scope of the present invention is intended to be limited only by the explicit terms of the claims.
[0020] The present invention comprises an improvement in composite paper-based wallboard tape. Specifically, in the preferred embodiment of the invention, the tape comprises one or more raised beads adhered to the tape and, preferably, run adjacent the outer edges of the tape to improve tape adherence to the wallboard compound. The tape may further include one or more PVC strips that are preferably located along the length of the tape and between the raised beads. The beads may be continuous or interrupted.
[0021] In that regard and referring to FIGS. 1 and 2 , a first embodiment of the present invention is shown. The first embodiment comprises a standard paper-based wallboard tape 10 . The tape 10 preferably defines a plurality of punctures 11 for allowing joint compound to more quickly dry. Adhered to a top surface 12 of the tape 10 is a skim coat or tapered coat of an adhesive 14 , preferably a hot melt material. The hot melt material is preferably a polyamide hot melt material. Furthermore when the adhesive 14 is applied, two raised beads 16 of adhesive are formed, as shown in FIG. 3 . Although the beads 16 are preferably formed by the adhesive 14 , it is within the scope of the present invention to apply a separately formed bead 16 to the tape 10 by using the adhesive 14 . Also applied to the adhesive are two stiffening strips 18 . The stiffening strips 18 are preferably made from polyvinyl chloride (PVC) and provide a rigid, straight surface, so that tape 10 will provide a flat, straight seam whether the tape 10 is covering a flat seam of two adjacent pieces of wallboard or is folded to form an inside or outside corner bead where two pieces of wallboard meet at an angle.
[0022] The tape 10 is preferably about 2 inches wide and about 0.009 inches thick and the stiffening strips 18 are preferable about 0.719 inches wide each and about 0.016 inches thick and separated by about 0.063 inches. Moreover, the raised beads are preferably about 0.015 in height above the skim coat of adhesive which is about 0.002 in thickness. The raised beads 16 generally form an arcuate top surface 20 .
[0023] Referring to another embodiment of the present invention in FIGS. 5-8 , adhered to a top surface 102 of a paper-based wallboard tape 100 is a skim coat or tapered coat of an adhesive 104 , also preferably a hot melt material and more preferably a polyamide hot melt material. Furthermore, when the adhesive 104 is applied, four raised beads 106 and 108 of adhesive are formed, as shown in FIG. 5 . Although the beads 106 and 108 are preferably formed by the adhesive, it is within the scope of the present invention to apply a separately formed bead to the tape 100 by using the adhesive. Also applied to the adhesive are two stiffening strips 110 . The stiffening strips 110 are preferably made from polyvinyl chloride and provide a rigid, straight surface, so that tape will provide a flat, straight seam whether the tape covers a flat seam of two adjacent pieces of wallboard or is folded to form an inside or outside corner bead where two pieces of wallboard meet at an angle. Also provided on an underside 112 of the tape 100 is a protuberance 114 , preferably formed from a polyamide hot melt material.
[0024] The tape 100 , in one embodiment, is preferably about 3 inches wide and about 0.009 inches thick, and the stiffening strips 18 are preferable about 1.063 inches wide and about 0.025 inches thick each and separated by about 0.125 inches. The raised beads 106 are preferably about 0.015 inches in height above the skim coat or tapered coat of adhesive, which is about 0.002 inches in thickness, and the beads are about 0.030 inches wide. Moreover, the raised beads 108 are preferably about 0.020 inches in height above the skim coat or tapered coat of adhesive and about 0.040 inches wide. The raised beads 106 and 108 generally form arcuate top surfaces 116 and 118 . The protuberance 114 is preferably about 0.125 inches wide and about 0.006 inches tall and has a top surface 122 that forms an arcuate surface. The arcuate surface preferably has a radius of about 0.329 inches.
[0025] The tape 100 , in another embodiment, is preferably about 4.125 inches wide and about 0.009 inches thick, and the stiffening strips 18 are preferable about 1.500 inches wide and about 0.030 inches thick each and separated by about 0.125 inches. The raised beads 106 are preferably about 0.015 inches in height above the skim coat or tapered coat of adhesive, which is about 0.002 inches in thickness, and the beads 106 are about 0.030 inches in width. Moreover, the raised beads 108 are preferably about 0.024 inches in height above the skim coat or tapered coat of adhesive and about 0.048 inches in width. The raised beads 106 and 108 generally form arcuate top surfaces 116 and 118 . The protuberance 114 is preferably about 0.125 inches wide and about 0.006 inches tall and has a top surface 122 that forms an arcuate surface. The arcuate surface preferably has an about 0.329 inch radius.
[0026] Referring to FIG. 9 , the wallboard tape 100 according to the present invention is applied to wallboard A and B by first providing a layer of wallboard compound to the wallboard seam to be taped. Next, the wallboard tape is applied to the wallboard compound with the beads 106 and 108 facing the wallboard and the applied wallboard compound. The tape 100 is then embedded into the wallboard compound with a trowel, which forces the beads 106 and 108 into the compound for firm adhesion of the tape 100 to the wallboard and wallboard compound. A top layer of wallboard compound is applied to the tape which is sanded to finish. Further layers of wallboard compound may be added and sanded to provide an appropriate finish. The tape 10 is similarly applied.
[0027] Referring to FIGS. 10 and 11 , in a variation of the first embodiment, the adhesive may be applied on about a 0.002 inch to 0.010 inch taper below the stiffening strip to provide it on a taper. This is to accommodate drywall tapers who prefer such a taper to assist them in applying drywall compound. Also provided is a tapered bead between the stiffening strips 18 of hot melt material. In this embodiment, the distance between the stiffening strips 18 is preferably twice the thickness of the stiffening strips 18 .
[0028] While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims.
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A wallboard tape including a paper tape having two outer edges. At least one pair of raised beads are adhered to the tape and extend parallel to the outer edges of the tape. The beads may optionally be formed on the tape from a hot melt adhesive and optionally have a generally arcuate top surface. At least one polyvinyl chloride stiffening strip may optionally be adhered to the tape with a hot melt adhesive and a protuberance on the side of the tape opposite the beads and running the length of the tape near the center of the tape also may optionally be applied.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/377,650, filed May 6, 2002, and is a continuation-in-part of a U.S. patent application entitled “Collaboration between Wireless LAN Access Points,” filed Aug. 7, 2002, whose disclosure is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to local area network (LAN) communications, and specifically to methods and devices for improving the performance of wireless LANs.
BACKGROUND OF THE INVENTION
[0003] Wireless local area networks (WLANs) are gaining in popularity, and new wireless applications are being developed. The original WLAN standards, such as “Bluetooth” and IEEE 802.11, were designed to enable communications at 1-2 Mbps in a band around 2.4 GHz. More recently, IEEE working groups have defined the 802.11a, 802.11b and 802.11g extensions to the original standard, in order to enable higher data rates. The 802.11a standard, for example, envisions data rates up to 54 Mbps over short distances in a 5 GHz band, while 802.11b defines data rates up to 22 Mbps in the 2.4 GHz band. In the context of the present patent application and in the claims, the term “802.11” is used to refer collectively to the original IEEE 802.11 standard and all its variants and extensions, unless specifically noted otherwise.
[0004] The theoretical capability of new WLAN technologies to offer enormous communication bandwidth to mobile users is severely hampered by the practical limitations of wireless communications. Indoor propagation of radio frequencies is not isotropic, because radio waves are influenced by building layout and furnishings. Therefore, even when wireless access points are carefully positioned throughout a building, some “black holes” generally remain—areas with little or no radio reception. Furthermore, 802.11 wireless links can operate at full speed only under conditions of high signal/noise ratio. Signal strength scales inversely with the distance of the mobile station from its access point, and therefore so does communication speed. A single mobile station with poor reception due to distance or radio propagation problems can slow down WLAN access for all other users in its basic service set (BSS—the group of mobile stations communicating with the same access point).
[0005] The natural response to these practical difficulties would be to distribute a greater number of access points within the area to be served. If a receiver receives signals simultaneously from two sources of similar strength on the same frequency channel, however, it is generally unable to decipher either signal. The 802.11 standard provides a mechanism for collision avoidance based on clear channel assessment (CCA), which requires a station to refrain from transmitting when it senses other transmissions on its frequency channel. In practice, this mechanism is of limited utility and can place a heavy burden on different BSSs operating on the same frequency channel.
[0006] Therefore, in high data-rate 802.11 WLANs known in the art, access points in mutual proximity must use different frequency channels. Theoretically, the 802.11b and 802.11g standards define 14 frequency channels in the 2.4 GHz band, but because of bandwidth and regulatory limitations, WLANs operating according to these standards in the United States actually have only three different frequency channels from which to choose. (In other countries, such as Spain, France and Japan, only one channel is available.) As a result, in complex, indoor environments, it becomes practically impossible to distribute wireless access points closely enough to give strong signals throughout the environment without substantial overlap in the coverage areas of different access points operating on the same frequency channel.
[0007] Access points in a WLAN system are typically interconnected by a wired LAN to communicate with a hub. The LAN serves as a distribution system (DS) for exchanging data between the access points and the hub. This arrangement enables the mobile stations to send and receive data through the access points to and from external networks, such as the Internet, via an access line connected to the hub.
[0008] Most commonly, the LAN used as a DS is an Ethernet LAN, operating in accordance with the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) method of media access control (MAC) defined in IEEE Standard 802.3 (2000 Edition), which is incorporated herein by reference. The terms “Ethernet,” “CSMA/CD” and “802.3” are used in the art interchangeably to refer to LANs of this type. Ethernet LANs are typically capable of carrying data at high speeds—greater than the aggregate speed of wireless communications between the access points and mobile stations. For example, a 100BASE-T Ethernet LAN is capable of carrying data over twisted pair cabling at 100 Mb/s. Message latency on the LAN is relatively high, however, generally on the order of milliseconds, due mainly to collision avoidance mechanisms specified by the 802.3 standard and the lack of a fragmentation mechanism at the 802.3 MAC layer. Another factor contributing to latency in Ethernet LANs is that the minimum frame size permitted by the standard is 64 bytes (plus 8 more bytes for the frame preamble and start frame delimiter), while the maximum frame size is more than 1500 bytes.
SUMMARY OF THE INVENTION
[0009] It is an object of some aspects of the present invention to provide methods and devices for enhancing the coverage and speed of WLAN systems.
[0010] It is a further object of some aspects of the present invention to provide methods and devices that enable a wired LAN to be used for high-speed, low-latency communications.
[0011] In preferred embodiments of the present invention, a WLAN system comprises multiple wireless access points distributed within a service region. The access points are linked together by cables in a local area network (LAN), typically an Ethernet LAN, which conveys data to and from mobile stations served by the access points. In order to provide complete coverage of the service region, with strong communication signals throughout the region, the access points are preferably closely spaced, and their areas of coverage may substantially overlap one another, unlike WLANs known in the art.
[0012] In order to deal with this overlap, the access points communicate among themselves using a novel, low-latency protocol over the LAN. When a mobile station sends an uplink message attempting to initiate communications in a given frequency channel, a number of access points operating in this frequency channel may typically receive the message. These access points arbitrate among themselves by sending messages over the LAN, using the novel protocol to determine which access point will respond to the mobile station. The arbitration must be completed promptly, typically well below 10 μs. If the access points were limited to communicating over the LAN using Ethernet protocols, they would be unable to complete the arbitration within this tight limit because of the high latency inherent in Ethernet, as described above. Therefore, each access point receiving the uplink message preempts its Ethernet communications immediately, and uses the novel protocol of the present invention instead to send and receive the messages necessary for arbitration. Standard Ethernet transmissions may resume afterwards.
[0013] The use of the arbitration mechanism of the present invention allows access points to be deployed within the service region as closely as desired while avoiding mutual interference. As a result, mobile stations everywhere in the service region experience good radio coverage, without “black holes,” and can operate at optimal speed. Since the arbitration messaging among the access points takes advantage of an existing LAN among the access points (or a LAN that would be deployed as a DS for the WLAN in any case), the improved performance of the WLAN is achieved without substantial added hardware, by means of a very simple installation procedure.
[0014] Although preferred embodiments described herein are directed primarily to improving the coverage of WLAN systems, the principles of the present invention may be applied for other purposes, as well. Thus, the present invention may be employed to provide nodes in a LAN with dual MAC capabilities: a high-throughput MAC layer, such as a 100 Mb/s Ethernet MAC layer, used for general data communications; and a separate low-latency MAC layer, which is invoked when needed for sending short, high-priority messages, which are typically a microsecond or less in duration. The high-speed MAC can be used, for example, for synchronization and control signals that require low latency, and therefore cannot be carried over Ethernet. Ordinarily, in the absence of the low-latency MAC, additional cabling among the nodes would be required to carry these signals. The present invention resolves this deficiency of the prior art, allowing LAN cabling and equipment to be used for dual purposes.
[0015] There is therefore provided, in accordance with a preferred embodiment of the present invention, a method for mobile communication, including:
[0016] arranging a plurality of access points in a wireless local area network (WLAN) to communicate on a common frequency channel with a mobile station;
[0017] linking the access points together by cables in a wired local area network (LAN);
[0018] receiving at one or more of the access points an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel;
[0019] sending one or more messages over the LAN among the access points, responsive to receiving the uplink signal;
[0020] arbitrating among the access points based on the messages so as to select one of the access points to respond to the uplink signal; and
[0021] transmitting a response from the selected one of the access points to the mobile station.
[0022] Preferably, linking the access points includes arranging the access points to convey data to and from the mobile station via the LAN, in addition to sending the messages over the LAN responsive to receiving the uplink signal. Most preferably, arranging the access points to convey the data includes configuring the access points to convey the data in accordance with a first media access control (MAC) protocol characterized by a first latency, and sending the messages includes using a second MAC protocol, having a second latency lower than the first latency, to send the messages responsive to receiving the uplink signal. Typically, the first MAC protocol includes an Ethernet protocol.
[0023] Further preferably, sending the messages includes preempting conveying the data in accordance with the first MAC protocol in order to send the messages using the second MAC protocol. Typically, preempting conveying the data includes invoking a collision-avoidance mechanism provided by the first MAC protocol. Most preferably, preempting conveying the data includes interrupting transmission of a frame of the data in accordance with the first MAC protocol.
[0024] Preferably, sending the one or more messages includes sending broadcast messages from the access points receiving the uplink signal to the plurality of the access points.
[0025] Further preferably, arbitrating among the access points includes receiving and processing the messages at each of the plurality of the access points, so that each of the one or more of the access points receiving the uplink signal determines which one of the access points is to be selected to respond to the uplink signal. Most preferably, processing the messages includes selecting, responsive to the messages, the one of the access points that was first to receive the uplink signal.
[0026] Preferably, the access points have respective service areas, and wherein arranging the plurality of the access points includes arranging the access points so that the service areas substantially overlap.
[0027] In a preferred embodiment, arranging the plurality of the access points includes arranging the access points to communicate with the mobile station substantially in accordance with IEEE Standard 802.11, and arbitrating among the access points includes selecting the one of the access points to respond to the uplink signal within a time limit imposed by the IEEE Standard 802.11 for acknowledging the uplink signal.
[0028] There is also provided, in accordance with a preferred embodiment of the present invention, a method for network communication, including:
[0029] linking a plurality of nodes together in a local area network (LAN);
[0030] conveying data over the LAN among the nodes in accordance with a first media access control (MAC) protocol characterized by a first latency; and
[0031] preempting conveying the data in accordance with the first MAC protocol in order to pass a message over the LAN among the nodes using a second MAC protocol, having a second latency lower than the first latency.
[0032] In a preferred embodiment, the first MAC protocol includes an Ethernet protocol, and preempting conveying the data includes asserting a signal in accordance with a media independent interface (MII) between physical and MAC layers of the Ethernet protocol.
[0033] Additionally or alternatively, preempting conveying the data includes invoking a collision-avoidance mechanism provided by the first MAC protocol.
[0034] Preferably, preempting conveying the data includes interrupting transmission of a frame of the data in accordance with the first MAC protocol.
[0035] Most preferably, conveying the data includes establishing a synchronization between the nodes on the LAN in accordance with the first MAC protocol, and preempting conveying the data includes using the established synchronization to send the message using the second MAC protocol.
[0036] Additionally or alternatively, conveying the data includes sending data frames including a first type of error detection code, and wherein preempting conveying the data includes sending the message with a second type of error detection code, different from the first type.
[0037] There is additionally provided, in accordance with a preferred embodiment of the present invention, a system for mobile communication, including:
[0038] cables arranged to form a wired local area network (LAN); and
[0039] a plurality of access points interconnected by the LAN and arranged in a wireless local area network (WLAN) to communicate on a common frequency channel with a mobile station, the access points being adapted, upon receiving at one or more of the access points an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel, to send one or more messages over the LAN among the access points, responsive to receiving the uplink signal, and to arbitrate among the access points based on the messages so as to select one of the access points to respond to the uplink signal, and to transmit a response from the selected one of the access points to the mobile station.
[0040] There is further provided, in accordance with a preferred embodiment of the present invention, a system for network communication, including:
[0041] cables arranged to form a wired local area network (LAN); and
[0042] a plurality of nodes, which are linked together by the LAN and are adapted to convey data over the LAN among the nodes in accordance with a first media access control (MAC) protocol characterized by a first latency, and which are further adapted to preempt conveying the data in accordance with the first MAC protocol in order to pass a message over the LAN among the nodes using a second MAC protocol, having a second latency lower than the first latency.
[0043] There is moreover provided, in accordance with a preferred embodiment of the present invention, access point apparatus for deployment in a wireless local area network (WLAN) as one of a plurality of access points for mobile communication, the apparatus including:
[0044] a radio transceiver, which is configured to communicate on a predetermined frequency channel with a mobile station;
[0045] a physical layer interface, for connecting the access point to a wired local area network (LAN) interconnecting the access points; and
[0046] processing circuitry, which is adapted, when the transceiver receives an uplink signal transmitted over the WLAN by the mobile station on the predetermined frequency channel, to send and receive messages via the physical layer interface over the LAN to and from the plurality of access points, and to arbitrate among the access points based on the messages so as to select one of the access points to respond to the uplink signal, and to control the transceiver so that the transceiver returns a response to the mobile station subject to the arbitration protocol.
[0047] Preferably, the processing circuitry is adapted to preempt conveying the data in accordance with the first MAC protocol in order to send the messages using the second MAC protocol. Most preferably, the processing circuitry includes a multiplexer, which is adapted invoke a collision-avoidance mechanism provided by the first MAC protocol in order to preempt conveying the data. Further preferably, the processing circuitry includes a MAC processor, which is adapted to generate frames of the data for transmission in accordance with the first MAC protocol, and the multiplexer is adapted to use the collision-avoidance mechanism in order to cause the MAC processor to interrupt transmission of one of the frames of the data.
[0048] There is furthermore provided, in accordance with a preferred embodiment of the present invention, node apparatus for deployment as one of a plurality of nodes in a local area network (LAN), the apparatus including:
[0049] a physical layer interface, for connecting the node to the LAN; and
[0050] processing circuitry, which is adapted to convey data via the physical layer interface over the LAN in accordance with a first media access control (MAC) protocol characterized by a first latency, and which is further adapted to preempt conveying the data in accordance with the first MAC protocol in order to pass a message over the LAN using a second MAC protocol, having a second latency lower than the first latency.
[0051] Preferably, the processing circuitry includes:
[0052] a first MAC processor, for conveying the data in accordance with the first MAC protocol;
[0053] a second MAC processor, for sending and receiving the message in accordance with the second MAC protocol; and
[0054] a multiplexer, coupling the first and second MAC processors to the physical layer interface, which is adapted to preempt the first MAC processor so as to enable the second MAC processor to send the message.
[0055] The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] FIG. 1 is a block diagram that schematically illustrates a WLAN system, in accordance with a preferred embodiment of the present invention;
[0057] FIG. 2 is a block diagram that schematically shows details of access points in a WLAN system, in accordance with a preferred embodiment of the present invention;
[0058] FIG. 3 is a block diagram that schematically illustrates a communication protocol stack with dual MAC layers, in accordance with a preferred embodiment of the present invention;
[0059] FIG. 4 is a block diagram that schematically illustrates a message packet exchanged between access points in a WLAN system, in accordance with a preferred embodiment of the present invention; and
[0060] FIG. 5 is a flow chart that schematically illustrates a method for arbitrating among wireless access points in a WLAN system, in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0061] FIG. 1 is a block diagram that schematically illustrates a wireless LAN (WLAN) system 20 , in accordance with a preferred embodiment of the present invention. System 20 comprises multiple access points 22 , which are configured for data communication with mobile stations 24 . The mobile stations typically comprise computing devices, such as desktop, portable or handheld devices, as shown in the figure. In the exemplary embodiments described hereinbelow, it is assumed that the access points and mobile stations communicate with one another in accordance with one of the standards in the IEEE 802.11 family and observe the 802.11 medium access control (MAC) layer conventions. Details of the 802.11 MAC layer are described in ANSI/IEEE Standard 801.11 (1999 Edition), and specifically in Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, which is incorporated herein by reference. The principles of the present invention, however, are not limited to the 802.11 standards, and may likewise be applied to substantially any type of WLAN, including HiperLAN, Bluetooth and hiswan-based systems.
[0062] Access points 22 are connected to an Ethernet switching hub 26 by a wired LAN 28 , which serves as the distribution system (DS) for exchanging data between the access points and the hub. As noted above, this arrangement enables mobile stations 24 to send and receive data through access points 22 to and from an external network 30 , such as the Internet, via an access line 32 connected to hub 26 . LAN 28 is typically a 100BASE-TX LAN, operating in half-duplex mode, as specified by the 802.3 standard. Alternatively, LAN 28 may comprise substantially any Ethernet standard LAN.
[0063] As described in the above-mentioned U.S. patent application (“Collaboration between Wireless LAN Access Points”), access points 22 in system 20 are preferably closely spaced, so that radio waves may typically reach mobile station 24 from multiple access points simultaneously on the same frequency channel. By the same token, radio messages transmitted by mobile station 24 may be received at about the same time by multiple access points. In WLAN systems known in the art, under these circumstances, mobile station 24 would receive downlink messages from two or more of the access points, which would probably result in inability of the mobile station to communicate with any of the access points. In preferred embodiments of the present invention, the access points collaborate to resolve this conflict by exchanging arbitration messages with one another using a novel, high-speed protocol over LAN 28 , as described hereinbelow. Preferably, the arbitration messages are broadcast by all the access points that receive an uplink signal from a given mobile station, to all the other access points. Based on the arbitration messages, the access points decide which access point is to serve a given mobile station (usually the closest access point to the mobile station, meaning the first access point to send out an arbitration message over LAN 28 in response to a given uplink message). The other access points meanwhile refrain from interfering.
[0064] Ordinarily, in a conventional WLAN, when an access point receives an uplink message from a mobile station, it answers immediately with an acknowledgment (ACK). If the mobile station does not receive the ACK within a given timeout period (known as the interframe space, or IFS), typically 10 μs, it subsequently submits an automatic repeat request (ARQ). Ultimately, the mobile station will treat the message exchange as having failed if it repeatedly does not receive the required ACK. Therefore, to maintain 802.11 compatibility in system 20 , one—and only one—of the receiving access points must return an ACK to mobile station 24 within the 10 μs limit. This constraint requires that the arbitration process among the access points be completed in substantially less than 10 μs. For this purpose, access points 22 are provided with dual MAC functions: an Ethernet MAC for conventional data communications, and a novel low-latency MAC for arbitration, as described below.
[0065] FIG. 2 is a block diagram that schematically shows details of access points 22 , in accordance with a preferred embodiment of the present invention. Access point 22 is connected to hub 26 by wires 33 of LAN 28 . Hub 26 typically comprises a standard Ethernet switching hub, as is known in the art, which is additionally programmed to recognize and rapidly switch the (non-Ethernet) arbitration messages exchanged among the access points. Access point 22 comprises a physical layer interface (PHY) 34 , which transmits and receives signals over wires 33 in accordance with the 100BASE-TX PHY layer specification of the 802.3 standard. Preferably, PHY 34 operates in a half-duplex mode, as provided by the standard.
[0066] A multiplexer 35 attaches PHY 34 to two different MAC processors: an Ethernet frame processor 36 and a collaboration message processor 38 . As a rule, the multiplexer gives priority to delivering outgoing arbitration messages from the message processor, blocking the frame processor and preempting any transmission of pending Ethernet frames in the meanwhile. Based on these arbitration messages, processor 38 interacts with and controls a WLAN transceiver 37 . Transceivers 37 communicate over the air with mobile stations 24 in accordance with the applicable WLAN standard.
[0067] The elements of access point 22 shown in FIG. 2 may comprise individual, separate components, or they may alternatively be combined together in a single integrated circuit chip or chip set. Although multiplexer 35 and message processor 38 are novel and unique to the present invention, the other elements of the access point shown in FIG. 2 (including PHY 34 , Ethernet frame processor 36 and transceiver 37 ) are available off-shelf as standard components. The multiplexer, Ethernet frame processor and message processor may also be implemented as software processes running on a single microprocessor, as long as the processing speed of the microprocessor is sufficient.
[0068] FIG. 3 is a block diagram that schematically illustrates a protocol stack implemented by the components of access point 22 , in accordance with a preferred embodiment of the present invention. PHY 34 implements a standard physical layer protocol 42 , in accordance with the 802.3 standard, such as the 100BASE-TX protocol. The functions of a MAC protocol layer 44 , however, are divided among several components. Ethernet frame processor 36 implements a standard 802.3 MAC protocol 46 . Message processor 38 , on the other hand, uses a novel low-latency MAC protocol 48 for arbitration messaging among the access points. A combination (COMBO) layer 50 is provided by multiplexer 35 to interface between the physical layer protocol and the alternative MAC protocols.
[0069] Preferably, COMBO layer 50 uses a Machine-Independent Interface (MII) to interface with the physical and Ethernet MAC layers, and optionally with low-latency MAC 48 , as well. The MII, as defined in detail in Chapter 22 of the 802.3 standard, provides standard primitives for communication between the Ethernet MAC layer and the 100BASE-TX PHY layer. By using these primitives in the manner provided by the 802.3 standard, the operation of COMBO layer 50 is transparent to the Ethernet MAC and PHY layers. In other words, these layers operate in the conventional fashion, and need not be modified to accommodate low-latency MAC 48 .
[0070] At a higher protocol level, network and application layers 52 are responsible for conveying data to and from mobile stations 24 between WLAN transceiver 37 and LAN 28 . These conventional functions are beyond the scope of the present invention, and their implementation will be apparent to those skilled in the art.
[0071] An access point collaboration layer 54 is responsible for generating arbitration messages to be transmitted over LAN 28 via high-speed MAC layer 48 and for receiving and processing incoming arbitration messages from other access points. Layer 54 uses the arbitration message information to determine which of the access points should respond to a given uplink message received by transceiver 37 and outputs control signals to the transceiver accordingly. These operations, and associated details of the operation of low-latency MAC layer 48 and COMBO layer 50 , are described further hereinbelow with reference to FIG. 5 .
[0072] FIG. 4 is a block diagram that schematically illustrates a broadcast packet 60 sent over LAN 28 by one of access points 22 , in accordance with a preferred embodiment of the present invention. Packet 60 is used by the access points to convey arbitration messages to the other access points upon receiving uplink communications from one of mobile stations 24 , as described below with reference to FIG. 5 . The packet comprises a source address (SA) 62 , a message body 64 and an error checking code 66 , typically a cyclic redundancy code (CRC), as is known in the art.
[0073] For rapid communications between the access points, it is desirable that packet 60 be as short as possible, most preferably no more than 16 bits. Thus, SA 62 simply identifies the sending access point, in a unique, proprietary format, which also allows hub 26 to recognize the packet as a broadcast packet. Since the hub distributes the packet to all the access points, there is no need for a destination address. Hub 26 not only has the capabilities of a standard Ethernet switching hub, but also has added hardware and software capabilities that enable it to recognize packet 60 and distribute it with highest priority. For this purpose, hub 26 preferably includes dedicated broadcast circuitry, since otherwise the standard 802.3 switching circuits would regard packet 60 as erroneous and would therefore drop it. Most preferably, hub 26 , like access point 22 , has an added a buffer layer between the standard PHY layer and two different MAC layers: the standard 802.3 switching MAC and the novel low-latency broadcast MAC of the present invention. Since 100BASE-TX uses synchronous links (“always on”), hub 26 preferably includes an elastic buffer (not shown) for use in broadcasting packet 60 from one input port to many output ports in parallel.
[0074] Message body 64 identifies the mobile station that sent the uplink message reported by packet 60 . For efficient communications, the mobile station identification is abridged, by hashing to a 16-bit code, for example. Message processor 38 in each of the access points receiving packet 60 decodes SA 62 and message body 64 . The message processor thus resolves the identities of both the mobile station that sent the uplink message and the access point that received the uplink message and issued packet 60 . Based on the contents of packets that it receives and the times at which it receives them, the message processor decides whether this access point should respond to the uplink message. Typically, the first access point to send out a broadcast packet in response to a given uplink message is chosen to respond to the message. Optionally, message body 64 may include other parameters, such as the power level of the received uplink message and/or an identification of the antenna on which the access point received the message. (For diversity purposes, access points generally have multiple antennas.) These additional parameters may be used, in addition to or instead of the time of receipt of packet 60 , in arbitrating among the access points.
[0075] Code 66 is preferably an 8- or 16-bit CRC, which is used by message processor 38 to verify the correctness of the contents of packet 60 . Most preferably, code 66 uses a different coding scheme from that provided by the 802.3 standard. As a result, if packet 60 is accidentally passed to Ethernet MAC processor 36 , the Ethernet MAC layer will be unable to correctly decode the CRC and will therefore discard the packet.
[0076] FIG. 5 is a flow chart that schematically illustrates a method for establishing communications between mobile station 24 and one of access points 22 in system 20 , in accordance with a preferred embodiment of the present invention. Further details of this method are described in the above-mentioned U.S. Patent Application (which uses a dedicated, shared medium to exchange arbitration messages between the access points, rather than LAN 28 ). Access points 22 transmit beacon signals on their common frequency channel, giving the time base with which the mobile station should synchronize its communications and indicating the BSS identification (BSSID) of the access point. In 802.11 WLAN systems known in the art, each access point has its own unique BSSID. In system 20 , however, multiple access points share the same BSSID, so that they appear logically to the mobile station to be a single, extended, distributed access point, which has multiple antennas at different locations. The time bases of the access points are mutually synchronized using synchronization messages sent over LAN 28 (in the form of packet 60 ), and the beacon signals transmitted by the access points are interlaced to avoid collision between them.
[0077] When mobile station 24 receives a beacon signal of sufficient strength, it extracts the BSSID and time base from the signal, and uses them to send an uplink message, which is received by one or more of the access points, at an uplink step 70 . The actions of the mobile station in this and other steps are completely in accordance with the 802.11 standard. In other words, the present invention can be implemented in a manner that is by definition transparent to and requires no modification of existing mobile stations. Typically, the first uplink signal sent by the mobile station is an association request message that is addressed to the BSSID and indicates the MAC address of the mobile station. Following this uplink message, one—and no more than one—of the receiving access points must return an ACK to mobile station 24 within the 10 μs IFS limit, as explained above.
[0078] To determine which of the access points will respond to the association request message, access points 22 carry out an arbitration procedure using LAN 28 . For this purpose, message processors 38 in all access points that received the uplink message from mobile station 24 prepare broadcast packets 60 , at a packet generation step 72 , in order to give notice to the other access points that they have received an uplink message. High-speed MAC layer 48 notifies COMBO layer that it has a packet ready to transmit, preferably by setting a transmit enable flag. For example, assuming the high-speed MAC and COMBO layers communicate in accordance with the MII defined by the 802.3 standard, the high-speed MAC layer asserts the TX_EN signal synchronously with the first nibble of the transmitted packet. It continues to assert this flag until the entire packet has been transmitted.
[0079] As soon as low-latency MAC layer 48 of message processor 38 notifies COMBO layer 50 of multiplexer 35 that it has a packet to transmit, the COMBO layer immediately breaks off any Ethernet communications by access point 22 , at an Ethernet blocking step 74 . Preferably, the COMBO layer notifies Ethernet MAC layer 46 that a collision has been detected on the LAN, by asserting the COL signal provided by the MII of the 802.3 standard. When such a collision condition occurs, the Ethernet MAC layer terminates transmission of any frames in progress, and defers further transmissions as long as the COL flag remains asserted. If the COMBO layer was in the process of transmitting an Ethernet frame, it immediately stops transmission and requests that PHY layer 42 deliberately corrupt the contents of the frame in such a manner that a receiver will detect the corruption with the highest degree of probability. For this purpose, the COMBO layer preferably asserts the TX_ER and TX_EN signals, as provided by the MII, on its interface with the PHY layer. In response, as specified in section 22.2.2.8 of the 802.3 standard, the PHY layer will emit one or more symbols that are not part of the valid data or delimiter set provided by the standard. These symbols will cause all receivers of the frames to immediately discard them.
[0080] After asserting the COL and TX_ER flags (preferably for no more than one clock period), COMBO layer 50 transmits the broadcast message prepared by low-latency MAC layer 48 , at a broadcast transmission step 76 . The COMBO layer preferably asserts the TX_EN flag in order to instruct PHY layer 42 to transmit the packet. Even when the PHY layer is idle, it continues to transmit and receive idle symbols over LAN 28 in order to maintain synchronization, as mandated by the 802.3 standard. Therefore, there is essentially no synchronization delay involved in beginning to send or receive an arbitration broadcast packet over the LAN.
[0081] All access points 22 receive the broadcast packets sent over LAN 28 , at a message reception step 78 . When COMBO layer 50 receives one of the broadcast packets, it passes the packet immediately to low-latency MAC layer 48 . The MAC layer passes the message information to collaboration layer 54 , which arbitrates among the access points that sent broadcast packets, at an arbitration step 80 , in order to determine which access point will respond to the uplink message received at step 70 . The same arbitration takes place at all the access points. Each access point is able to determine whether it was first to send its message, or whether another access point preceding it, by comparing the time of receipt of these broadcast messages to the time at which the access point sent its own broadcast message. (Access points operating on other frequency channels, as well as access points on the same frequency channel that did not receive an uplink signal from the mobile station identified in the broadcast message, may ignore the message.)
[0082] Typically, the access point that was able to send its broadcast message first in response to an uplink message from a given mobile station is in a good position to continue communications with the mobile station. Therefore, all the access points independently choose this first access point to respond to mobile station 24 . The 802.11 standard supports a large range of data rates for transmission (1 to 54 Mb/s). The mobile station tries to transmit packets as fast as possible, link permitting. Therefore, in general, only the access points that are close enough to the mobile station to receive the high-rate transmission will be in contention to serve the mobile station, and the winning access point must implicitly be among the best receivers of the uplink message in question.
[0083] Alternatively or additionally, other criteria, such as received signal power, may be applied in choosing the “winning” access point, as long as the criteria are applied uniformly by all the access points. Preferably, if a deadlock occurs (such as when two access points send their broadcast messages at the same instant), a predetermined formula, which may be based on the received signal power, is applied by all the access points to resolve the deadlock uniformly.
[0084] The winning access point sends the required ACK message to mobile station 24 , at an acknowledgment step 82 . As noted above, the ACK must be sent within a short time, typically 10 μs, and steps 70 - 80 must all be completed within this time. Access points 22 are able to meet this time constraint by using LAN 28 in the manner described above. After sending the ACK, the winning access point typically sends an association response message to mobile station 24 , and then continues its downlink transmission to the mobile station as appropriate.
[0085] The winning access point continues serving the mobile station until the mobile station sends another uplink message. The arbitration protocol described above is then repeated. A different access point may be chosen to serve the mobile station in the next round, particularly if the mobile station has moved in the interim. Even if the mobile station has moved, there is no need to repeat the association protocol. As noted above, all the access points belong to the same BSS, as though they were a single extended access point. Therefore, the same association of the mobile station is therefore maintained even if the arbitration process among the access points chooses a different “winner” to respond to the next uplink packet from the mobile station.
[0086] The LAN communication architecture shown in FIG. 2 and the protocol stack shown in FIG. 3 are useful not only in improving the coverage of WLAN systems, as described above, but also in other network communication contexts. As noted above, the present invention may thus be employed to provide nodes in a LAN with dual MAC capabilities: a medium-latency MAC layer, such as an Ethernet MAC layer, used for general data communications; and a separate low-latency MAC layer, which is invoked when needed for sending short, urgent messages. Low-latency MAC layer 48 can be used, for example, for synchronization and control signals that require low latency, and therefore cannot be accommodated by Ethernet MAC layer 46 . The high-speed MAC and COMBO layers of the present invention can similarly be used in a dual-MAC configuration alongside other types of MAC and data link protocol layers known in the art. For example, the low-latency MAC layer could be used in a real-time location system, to use multiple radio propagation measurements to locate people in an office building or plant.
[0087] It will thus be appreciated that the preferred embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
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A method for mobile communication includes arranging a plurality of access points in a wireless local area network (WLAN) to communicate on a common frequency channel with a mobile station, and linking the access points together by cables in a wired local area network (LAN). When one or more of the access points receive an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel, the access points send messages over the LAN and arbitrate among themselves based on the messages so as to select one of the access points to respond to the uplink signal.
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FIELD OF THE INVENTION
The present invention relates generally to a system for creating menu choices of video games on a display from a group of video game menu options shown on the video display. The present invention also relates generally to a method for setting game credits in a video game machine and tallying a total currency amount fed into the machine.
BACKGROUND OF THE INVENTION
Devices which allow a user to select menu choices from a video display are well-known in the art. For example, FIG. 5 of U.S. Pat. No. 4,856,787 shows a touch screen display for making a game selection from a menu of games. U.S. Pat. No. 5,342,047 discloses a video lottery terminal with a touch screen user interface. The terminal permits a number of different games to be played on the same machine. The desired game is selected from a menu. One problem with such devices is that a game operator cannot quickly and easily change the menu. Such menus are typically preset in software and thus require advanced programming skills to modify.
Devices which allow a user to select one game from a menu of several games available for play often employ complex hardware and wiring and require insertion of a game cartridge into the device for each game available for selection. See, for example, U.S. Pat. Nos. 4,516,777, 4,922,420 and 5,114,157. If the game operator wishes to change one of the games available for play (and the menu of games available for play), the operator must physically access a bank of cartridges to change the cartridge in the slot.
Gaming devices which operate upon input of currency (either coin, token or paper money) typically track machine usage in a meter. In one technique, each currency input creates a pulse which sequentially advances the meter. In another technique, each currency input grants a predetermined number of game play credits and the meter is advanced by the granted number of play credits. Neither of these techniques are completely satisfactory for a game operator because the game operator is mainly interested in knowing the total value of currency in the currency receptacle before it is emptied and counted. The first technique does not discriminate between types of currencies and only provides an indication of the total number of currency units (e.g., coins) in the receptacle. The second technique may not give an accurate accounting of the total value of currency because currency inputs do not always exactly correlate with play credits. Some gaming devices are capable of being set to provide bonus credits for additional currency inputs. For example, a gaming machine may be set to grant one game per quarter, but will grant five games per dollar (a bonus credit of one game). However, gaming devices which accept plural currency types (e.g., nickels, quarters, dollars) are relatively inflexible in setting currency/credit ratios. While the ratios for the total currency input may be adjusted, the ratios cannot be individually adjusted for inputs of each currency type.
Despite the existing systems for selecting menu items and modifying game selections, there is still a need for a simple, economical system for creating menus of selectable choices. The present invention fills this need by providing an apparatus and method which creates a video screen of menu choices from a simultaneously displayed group of menu options. In this manner, the game operator can be provided with a single cartridge or software program containing a large number of games, and can employ the menu creation feature to easily and quickly provide a subset of games which are selectable for play on a particular game machine. No cartridge switching or software reprogramming is required to change the game choices.
There is also still a need for controlling a gaming machine meter which advances the meter in accordance with the actual total value of currency entered into the gaming machine and which allows currency inserted/credits given ratios to be flexibly adjustable. The present invention fills these needs by providing an apparatus and method which allows the game operator to program the meter to advance in accordance with the exact value of the entered currency and to allow such ratios to be individually adjusted.
SUMMARY OF THE INVENTION
The present invention is an apparatus for providing menu choices of video games on a video screen having first and second regions. The apparatus comprises a mode selector, a video screen and a display controller. The mode selector sets the apparatus in one of either a programming mode or a menu choice selection mode. The video screen displays video game menu options and video game menu choices. The video game menu options are available for selection as video game menu choices. The display controller causes a simultaneous display of video game menu options and video game menu choices on the video screen when the mode selector is in the programming mode, and causes a display of video game menu choices when the mode selector is in the menu choice selection mode. The display controller also causes video game menu options selected from the second region to be displayed in the first region as a video game menu choice.
Another embodiment of the present invention comprises a method for tallying a total currency amount fed into a gaming machine which accepts a plurality of different types of coins. Each coin type represents a different number of currency units. The method comprises the steps of displaying a setup screen on a video display showing a representation of the plurality of different coin types and the total number of currency units associated with each coin type, selecting the total number of currency units to be associated with each coin type, and tallying the total currency amount fed into the machine based upon the number of coins deposited in the gaming machine and the total number of currency units selected for each coin type.
Another embodiment of the present invention provides a method for adjusting the coin/credit ratio in a gaming machine which accepts a plurality of different types of coins. The method comprises the steps of displaying a setup screen on a video display showing a representation of the plurality of different coin types and a number of game credits associated with a deposit of one coin of a particular type, and selecting the number of game credits to be associated with a deposit of one coin for each of the different coin types.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawing:
FIG. 1 is a main screen display of a game apparatus for accessing screens which create game menus and coin/credit setups;
FIG. 2 is a screen display for creating a game menu;
FIG. 3 is a screen display for creating a coin/credit setup; and
FIG. 4 is a schematic block diagram of apparatus for creating the screen displays in FIGS. 1-3.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Certain terminology is used herein for convenience only and is not be taken as a limitation on the invention. In the drawings, the same reference numerals are employed for designating the same elements throughout the several figures.
FIGS. 1-3 show screen displays for implementing the functions of the invention in a game apparatus. In the preferred embodiment of the invention, the video display is a touch screen. As is well-known in the art, indicators or images of buttons on a touch screen designate locations which, if touched, activate the function described within the location. Touch screen buttons may be replaced with hardwired keyboard buttons which correspond to the screen locations. The scope of the invention includes touch screen buttons and their equivalent keyboard buttons. Since touch screens are well-known in the art, general details of the touch screen are not further provided herein.
FIG. 1 shows a main screen display 10 for a game apparatus having a touch screen display. The main screen display 10 is not available to the game players. The game operator accesses the main screen display 10 by pressing an operator button on the game apparatus, inserting an operator key, entering a password, or the like. The main screen display 10 allows the operator to set or reset a plurality of game parameters, or to select a coin-in menu screen through indicator or button 12 or a game menu screen through indicator or button 14. To exit the main screen display 10, Exit Setup button 15 is touched. Thereupon, the game apparatus either enters a menu choice selection mode (described in more detail below) or an attract mode from which the menu choice selection mode can be entered.
FIG. 2 shows a game menu screen display 16 which appears upon touching button 14 in FIG. 1. The display 16 is divided into first, second and third regions 18, 20 and 22, respectively. The first region 18 is positioned along the bottom of the display 16 and provides a plurality of function buttons including a Default button 24, Clear All button 26, Clear One button 28, Format button 30, Menu 2 button 32, and Exit button 34. The function of the buttons 24-34 are described below. The second region 20 is positioned in a middle area of the display 16 and provides a plurality of selectable menu options. In one embodiment of the invention, the menu options are video games. In the embodiment depicted in FIG. 2, fourteen video games are displayed in the second region 20. Each video game may be selected as a menu option by touching the appropriate button 36-62. The third region 22 is positioned in a top area of the display 16 and provides a plurality of numbered locations for menu choices. In the embodiment depicted in FIG. 2, eight menu choice positions or locations 64-78 are displayed in the third region 22. Each location 64-78 has a first area for indicating the location number, a second area for indicating the menu choice and a third area for indicating the activation cost of the menu choice. The three areas are designated as a-c, respectively. For example, location 64 includes areas 64a, 64b and 64c. The menu choices placed in the menu choice locations 64-78 are selected from the menu options 36-62.
The game apparatus has two modes of operation relevant to the game menu screen display 16, a programming mode and a menu choice selection mode. In the programming mode, menu options 36-62 are selected by the operator from the second region 20 and placed in locations 64-78 in the third region 22 as designated by the operator. If the screen display 16 is a touch screen, the game operator touches an area a of a location 64-78 (e.g., 64a ) and then touches a menu option 36-62 in the second region 20. If the screen display 16 is a conventional video display, the game operator selects a location 64-78 by number and then selects a menu option 36-62 in the second region 20 by number or by cycling through the options 36-62 via a keyboard.
In one embodiment of the programming mode, as shown in FIG. 2, all of the menu options 36-62 remain on the second region 20 of the display 16, even after a selected menu option is placed in a designated location 64-78. In another embodiment of the programming mode (not shown), a selected menu option is deleted from the second region of the display 16 when it is placed in the designated location 64-68. The first embodiment allows a single menu option to be placed in more than one location 64-78, if desired.
In the menu choice selection mode, the programmed menu choices are selectable for game activation, either by touching the location of the desired game (if the screen display 16 is a touch screen), or by pressing the appropriate game number on a keyboard (if the screen display 16 is a conventional video display). In the preferred embodiment of the menu choice selection mode, the menu options 36-62 do not appear on the display 16. Also, blank (i.e., unselected) locations 64-78 do not appear. More specifically, when the menu programming is completed, the Format button 30 is touched to delete blank locations 64-78, if any, from the screen display 16. Then, the Exit button 34 is touched either once or twice (depending upon the stage of programming) to return the game apparatus to the main screen display 10. Upon exiting the main screen display 10, the game apparatus is placed in the menu choice selection mode. Thereupon, the menu options 36-62 disappear from the screen 16 and the menu choices become activatable.
During the programming mode, the Default button 24 places factory preset menu options 36-62 in predesignated menu choice locations 64-78. The Clear All button 26 deletes all previously selected menu choices from the locations 64-78. The Clear One button 28 deletes a selected menu choice from a selected location 64-78, the location being selected by touch or keyboard designation. The Menu 2 button 32 causes a second screen 16' (not shown) to be displayed which allows additional locations to be programmed. If more than eight games are programmed as menu choices, the eighth location 78 on the first screen 16 is touched in the menu selection mode to display the second screen 16' containing the additional menu choices.
During the programming mode, it is also possible to adjust the activation cost of a menu choice (e.g., the cost of playing one round of a video game). After a location 64-78 and menu option 36-62 is selected, a factory preset default activation cost of one credit appears in area c of the selected location (e.g., 64c). In the screen display 16 shown in FIG. 2, the factory preset default is 25 cents/credit. Successively touching the area c increments the activation cost by one credit (e.g., 50 cents, 75 cents, $1.00). After four credits are reached, the activation cost cycles back to one credit. When the desired activation cost is reached, the Exit button 34 is touched once. The next menu choice may now be programmed. If the Exit button 34 is touched again, the programming mode is exited and the game apparatus returns to the main screen display 10 of FIG. 1.
The game menu selection feature of FIG. 2 dramatically improves the versatility of game apparatus which allow plural video games to be played on one apparatus. The game operator is provided with a single cartridge or software program containing a large number of games. The game operator installs the cartridge or program, enters the screen 16 and selects a desired subset of games which are selectable for play on the apparatus. Subsequently, the game operator may quickly change the subset of video games selectable for play without replacing or modifying the cartridge or software program.
FIG. 3 shows a coin/credit setup screen display 80 which appears upon touching button 12 in FIG. 1. The word "coin" is employed above and hereafter interchangeably with the word "currency" to designate any form of coin, token or paper money currency. Although game apparatus such as video game terminals primarily accept coin-type currency, the scope of the invention includes all three forms of currency and their equivalents.
The coin/credit setup screen display 80 allows a game operator to adjust the coin/credit ratio for each coin type. The display 80 also allows the game operator to set meter pulses in accordance with the total coin value associated with each coin. To perform these functions, the display includes a grid of columns and rows of adjustable values. To fully understand FIG. 3, the contents of the rows and columns are described. Default values are set to "1".
The first column in display 80 shows a designation for a coin type. The first column is set at the factory and cannot be changed by the game operator. Each country has one or more currency units, and different types of coins or paper money which are equal to discrete amounts of currency units. For example, one currency unit in the United States is "cents." The United States Mint makes pennies equal to one currency unit, nickels equal to five currency units, dimes equal to ten currency units, quarters equal to twenty-five currency units, dollar coins or dollar bills equal to one hundred currency units, and so on. Likewise, a currency unit in Mexico is the peso and there are different types of coins which represent discrete numbers of pesos. The display 80 shows four electronic mech or mechanism inputs (1E, 2E, 3E and 4E) and two mechanical mech inputs (1M and 2M). 1E-4E and 1M-2M are representations of different currency units assigned by the game operator. The electronic mech inputs may be used when the game apparatus accepts more than one type of coin representing currency units. For example, 1E may represent a nickel, 2E may represent a quarter, and 3E may represent a dollar bill or coin. The mechanical mech inputs may be employed, for example, if tokens are used instead of coins.
The second column in the display 80 shows an operator selectable number representing a number of coins for each different currency type which will equal a given number of credits and meter pulses. For simplicity of understanding of the invention, the example shown in FIG. 3 uses the default value of "1". Thus, the coin/credit ratio will be 1/n, where n is the number of credits. However, the second column may be set to a discrete number such as "2", "3", and so on, as described in more detail below.
The third column in the display 80 shows the number of game credits granted for each input of the selected number of coins. The game operator also sets the numbers in the third column. The example shown in FIG. 3 is set to provide one credit per 5 currency units, assuming that 1E represents a nickel, 2E represents a quarter, and 3E represents a dollar bill or coin. Thus, one nickel provides one credit. To encourage more play, extra credits may be given for a quarter or dollar bill or coin. Instead of granting five credits for a quarter (25 units), six credits may be given. Instead of granting twenty credits for a dollar bill or coin (100 units), thirty credits may be granted.
As noted above, the number of coins in the second column and the number of credits granted in the third column are individually adjustable. In the example of FIG. 3, the coin/credit ratio will be 1/n, where n is the number of credits. However, the second column may be set to a discrete number such as "2". In another example, for a given coin input, the number of currency units can be set to "5" and the number of credits set to "2". Thus, five currency units (e.g., five nickels) would be required to achieve two credits, a 5/2 ratio. Different numbers and credits may be selected for each of the coin inputs 1E-4E and 1M-2M.
The fourth column in the display 80 shows the number of meter pulses for each for each input of the selected number of coins. The game operator also sets the numbers in the third column. The example shown in FIG. 3 shows that a 1E coin input (a nickel, in the example) provides five meter pulses, a 2E coin input (a quarter, in the example) provides twenty-five meter pulses and a 3E coin input (a dollar bill or coin, in the example) provides one hundred meter pulses. Thus, the meter pulse is equal to the number of currency units deposited in the game device (i.e., the total currency amount deposited in the game device). If the game operator checks the meter midday, and it registers 1,250, there would be $12.50 in the currency receptacle if the system was set for U.S. currency units.
The versatility of the coin/credit setup should now be apparent. The ratio of coins inserted to game credits granted per coin can be individually adjusted for each coin type. Furthermore, the ratio of coins inserted to game credits granted per coin can be adjusted independent of the meter pulse values so that the actual coin values can be tallied independent of the game credit values. The coin/credit setup may be individually programmed for the currency units available in each country, thereby allowing the game apparatus to be adaptable to the currency in any part of the world by simple operator programming steps.
If the display 80 is a touch screen, the settings are programmed by touching the appropriate location in the second, third or fourth column, and incrementing the number by one for each screen touch. If the display 80 is a conventional video display, the game operator selects a row and column, and location value by appropriate keyboard manipulation. If factory preset default values are desired, Default button 82 is touched or selected. When programming is completed, Exit button 84 is touched or selected to return the game apparatus to the main screen display 10.
FIG. 4 shows a schematic block diagram of a preferred embodiment of the game apparatus 100. A computer 102, such as a microprocessor, controls the operation of the game apparatus 100. The computer 102 is bidirectionally connected with memory 104 which contains apparatus control programs 106 and game programs 108. The game programs 108 are accessed by the computer 102 only when menu choices are selected during the menu choice selection mode. The control programs 106 perform all of the remaining tasks of the game apparatus 100, including generating the screens 10, 16 and 80, selecting the mode of operation, and storing parameters designated by the screens. A currency input device 110 is also connected to the computer 102 for receiving currency for operating the game apparatus 100. Touch screen display 112 is connected to the computer 102 through display controller 114. The touch screen display 112 is also bidirectionally connected with the computer 102 through interface board 116. The interface board 116 reads the inputs from the touch screen display 112. If the touch screen display 112 is replaced by a conventional video display, keyboard 118 connected to the computer 102 provides the inputs which would have been provided by the touch screen display 112. The game apparatus further includes a tally meter 120 for receiving pulses from the computer 102 in accordance with signals received from the currency input device 110 and the setup parameters from the screen 80 in FIG. 3.
Programming touch screen displays and programming touch screen locations to correlate with programmed selections are well-known in the art and, thus, are not described in detail herein.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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A system for allowing a game operator to individually tailor parameters of a video game machine provides a plurality of user interactive video screen displays for selecting the parameters. The parameters include the selection of menu choices of video games from a library of video games which are available for play on the machine.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional of U.S. patent Ser. No. 10/739,703 filed Dec. 18, 2003 now U.S. Pat. No. 7,025,708, a continuation of International Application No. PCT/DE02/02304, filed Jun. 24, 2002, and claims priority to German Patent Application No. 101 30 874.4, filed Jun. 27, 2001, which are hereby being incorporated by reference herein.
BACKGROUND INFORMATION
The present invention relates to a method for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission and/or an automated clutch in a creep drive mode of the vehicle. The present invention also relates to a method for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission and/or an automated clutch to establish the biting point of the clutch.
When a vehicle having an automated manual shift transmission and/or an automated clutch is moved in a creep drive mode to park in a parking space, for example, it must be ensured that the drive motor is not brought to stop by the driver of the vehicle during a braking procedure. For this purpose, opening the clutch when the driver actuates the brake of the vehicle is already known, it being possible to monitor the brake light switch in order to monitor the braking procedure. Therefore, digital information exists on whether the brake is actuated and the clutch must therefore be opened in order to avoid the engine dying because of the braking torque exerted on the engine.
However, when the driver only wishes to brake a little against a creep torque transmitted by the clutch during maneuvering, this procedure corresponds to a different driver intent than the sharp braking by the driver in order to avoid a collision during the parking procedure, for example.
By monitoring the engine speed, it is possible to activate more rapid opening of the clutch if the instantaneous engine speed falls below the engine-specific idle speed for a predetermined period of time. However, if a diesel engine is used as the drive motor, it reacts significantly more rapidly than a gasoline engine to a reduction in the engine speed, through an increase in the engine torque output because of the combustion, so that a noticeable drop in the engine speed may not be perceived, but rather the driver of the vehicle would perceive a push of the engine against his braking intent.
For the adaptation of the touch point or biting point of the clutch, exploiting the reaction of the engine in the event of an activation of the clutch using touch ramps when the brake is actuated is known. For this purpose, a low clutch torque is built up with an initially open clutch and the torque output by the engine is monitored. If the engine torque increases by a specific value over a specific period of time in relation to the engine torque before the touch point adaptation, then the biting point established by the clutch controller must be corrected in the open direction. For such a procedure, it is possible that the vehicle will roll free if the brake is only lightly actuated.
BRIEF SUMMARY OF THE INVENTION
The present invention is thus based on an object of providing a method for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission and/or an automated clutch in a creep drive mode which remedies the disadvantages described. In addition, the method for establishing the biting point of the clutch may also be improved.
According to the present invention, a method is thus provided for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission in a creep drive mode of the vehicle, according to which the clutch torque is changed as a function of at least one variable operating parameter of the vehicle which describes the creep drive mode of the vehicle. Very generally, this means that according to the present invention, one or more operating parameters of the vehicle are monitored which describe a slow drive mode or creep drive mode of the vehicle and, as a function of the operating parameter(s), the torque transmitted by the clutch is changed. Therefore, the creep drive mode of the vehicle may be improved in relation to the known method without the danger of the engine dying, since no longer only digital information in the form of the brake light switch is analyzed, but rather one or more operating parameters, which do not change digitally and which describe the creep drive mode of the vehicle, are analyzed.
Therefore, for example, in the event that there is a danger of the engine dying, the clutch torque may first be reduced at a relatively high speed, as a function of the operating parameter(s), and the clutch torque may then be reduced at a lower speed, so that, compared with a linear reduction of the speed of the clutch torque, a more comfortable creep drive mode is available that takes the driver's intent, which may be represented by an actuation of varying strength of the vehicle brake by the driver, for example, into consideration.
Therefore, according to one aspect according to the present invention, the operating parameter is the strength of the actuation of a vehicle brake which influences the speed of the vehicle. The strength of the actuation of the brake of the vehicle by the driver may therefore be considered, i.e., for example, the brake pressure for a hydraulic braking system or a current value, using which an electromechanical brake of the vehicle is actuated. In the event of a strong actuation of the brake by the driver, according to the present invention, the clutch is opened more rapidly and the clutch torque is therefore reduced more rapidly, since otherwise a braking torque would be transmitted via the transmission to the engine via the still closed or partially closed clutch, so that the engine speed would fall too greatly. A further reduction of the clutch torque may then occur at a lower speed, so that the comfort in the creep drive mode is improved and the creep drive mode is prolonged. Such behavior then corresponds to the behavior of a vehicle having a stepped automatic transmission.
Therefore, according to a further aspect according to the present invention, the operating parameter is the rotational speed and/or the engine torque and/or a variable of the drive motor of the vehicle derived therefrom. If a drop in the engine speed is perceived during the creep drive mode, due to a braking procedure initiated by the driver, for example, which leads to an engine speed significantly below the engine-specific idle speed for a predetermined duration, i.e., to a reduction of more than 100 rpm below the idle speed, for example, according to the present invention the clutch torque is reduced using a higher gradient than would be necessary in the event of lighter braking by the driver. In a similar way, the clutch torque is reduced more strongly if it is observed that the engine torque resulting from the combustion increases during braking significantly over a value of the engine torque typical for the idling of the engine. This typical value may be established as an average of the engine torque during creep before the actuation of the brake, for example. If an electric motor or a hybrid drive is used as the drive motor, the average value of the torque output during the creep drive mode before the actuation of the brake may also be established in a similar way.
Therefore, the typical torque behavior of the drive motor in idle is analyzed. If the engine reacts to braking with a significant increase in the torque, which may mean an increase to a value of more than 10 Nm, for example, the clutch torque is then reduced rapidly and the clutch is transferred into a slipping state. In this state, the clutch transmits a lower braking torque to the engine, and the engine torque for maintaining the idle speed no longer increases. The clutch torque may then be reduced using a lower gradient, having a value of 5 Nm/sec, for example.
In a similar way, according to the present invention, the clutch torque is reduced using a higher gradient if a drop in the engine speed is observed with an essentially negative gradient. Such a case exists, for example, when the engine speed is reduced using a gradient of 25 rad/s 2 , for example, which approximately corresponds to a reduction in the engine speed at a value of 250 rpm/sec.
According to a further aspect according to the present invention, the operating parameter is a rotational speed differential between the clutch input side and the clutch output side. This may be a rotational speed differential between the engine speed and the transmission input shaft speed, for example.
The method according to the present invention may also be advantageously used in power trains in which the clutch is not positioned between a drive motor and the transmission input, but rather at the output of the transmission or inside the transmission, for example. Thus, for example, positioning the clutch between a shaft and the transmission housing, in the event of which the clutch may act as a brake, or even, in transmissions with branched structures, positioning the clutch between two branches inside the transmission, is also possible. The action of the clutch and/or the brake on the engine then corresponds to the application in which the clutch is positioned between the engine and the transmission input.
In this case, it is provided according to the present invention that the clutch torque is reduced with a stronger approach when there is no essential rotational speed differential, since the clutch then does not yet operate with a significant slip. Therefore, the clutch is transferred more rapidly into a slipping state, through which the braking torque exerted on the engine via the clutch is reduced and the vehicle moves further in the creep drive mode. The clutch torque may then be reduced further at a rate of 5 Nm/sec, for example. Therefore, maneuvering which is comfortable for the driver may be implemented using the actuation of the brake against the creep torque. Through the initially great reduction in the clutch torque, the braking torque exerted on the engine is lower than the output torque provided by the engine in idle mode, so that the danger of the engine dying is eliminated and the driver may maneuver comfortably using the actuation of the brake.
According to a further aspect according to the present invention, the operating parameter is an accelerator pedal value. Therefore, if the brake and accelerator pedal or gas pedal are actuated simultaneously, a clutch torque may be set which allows the curb to be approached comfortably and is a function of the strength of the actuation of the brake and the accelerator pedal.
Using the change in the clutch torque as a function of at least one operating parameter of the vehicle provided according to the present invention, comfortable torque tracking may also be implemented. For this purpose, a driver's intent expressed by the actuation of the brake may advantageously be analyzed, since it may be assumed therefrom that there is a high probability that the driver wants to stop or he wants to cause a downshift action of the automated manual shift transmission if he actuates the brake of the vehicle strongly. The shifting time may be shortened if the minimum torque to be transmitted by the clutch is reduced starting from a specific threshold value of the strength of actuation of the brake, so that the opening of the clutch occurs rapidly. Therefore, it is also provided according to the present invention that the minimum torque and, in the course of the torque tracking, the torque to be transmitted by the clutch is reduced starting from a predetermined threshold value of the strength of the actuation of the brake of the vehicle, since the time necessary for opening the clutch is therefore reduced. It is possible in this case to perform the reduction of the minimum torque over multiple steps on the basis of multiple threshold values or even as a function of a brake pressure gradient.
The information obtained according to the method described above may also be used for the touch point adaptation.
According to one aspect of the present invention, a method is therefore also described for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission to establish the biting point of the clutch, in which the biting point established is shifted in the direction of an open clutch if the total torque of the engine torque and the engine moment of inertia exceeds a threshold value in the event of a reduction of the engine speed.
If it is determined during a braking action that the engine torque output by the engine plus the torque resulting from the reduction of the engine speed increases significantly, advantageously by more than 20 Nm, above a value characteristic for the idling of the engine, then, according to the present invention, the biting point of the clutch established by the controller is shifted toward the direction of the open clutch. This biting point established in this way is then used as the future biting point.
In a similar way, the biting point established is shifted in the direction of an open clutch if a rotational speed differential between the engine speed and the transmission input shaft speed is detected which is greater than a threshold value and the total torque exceeds the threshold value. Therefore, upon recognition of clutch slip and the sum of engine torque and engine moment of inertia being exceeded, the software biting point and/or the biting point established by the controller is shifted in the direction of the open clutch, and the controller will therefore disengage the clutch further in the future, since the biting point previously established as the setpoint value was too low in spite of slip in the clutch and the engine, in particular a diesel engine, has reacted thereto with a torque increase.
According to a refinement of the present invention, the biting point established is shifted in the direction of an open clutch if the rotational speed differential was detected, i.e., clutch slip has occurred for the first time and the engine speed falls below the idle speed. This variant is preferably applicable for a gasoline engine.
Very generally, it is therefore provided according to the present invention that the biting point established is shifted in the direction of an open clutch as a function of at least one operating parameter of the vehicle. This may also be the temperature of the clutch, for example.
According to the present invention, a further creep function of the vehicle is provided in such a way that the clutch torque is set to a further creep torque to maintain a creep drive mode if the accelerator pedal and the brake of the vehicle are not actuated. Therefore, an existing creep drive mode of the vehicle is maintained at the same level, for example during parking, if the driver does not operate the brake and the accelerator pedal.
According to the present invention, the further creep torque may be set in all gear stages, i.e., not only in the starting gears, for example the first and second gears as well as the reverse gear, but rather in all gear stages or driving stages provided by a transmission coupled to the clutch. This further creep torque may then be reduced if, on the basis of a rotational speed differential at the clutch causing the further creep drive mode, it is determined that clutch slip exists and therefore the output torque provided by the engine is no longer sufficient to maintain the further travel. Maintaining the further creep torque would then only lead to heating of the clutch because of increasing friction power.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described in greater detail in the following on the basis of the drawing.
FIG. 1 shows a diagram with a schematic illustration of the change in the clutch torque;
FIG. 2 shows a diagram with a schematic illustration of the change in the clutch torque in the event of the biting point adaptation if the biting point is too low;
FIG. 3 shows a diagram similar to FIG. 2 and a biting point that is too high; and
FIG. 4 shows a diagram with the curve of the clutch torque in the creep drive mode.
DETAILED DESCRIPTION
FIG. 1 of the drawing shows a schematic illustration of the change in the clutch torque as a function of the strength of the actuation of the brake by the driver of the vehicle.
This is a qualitative illustration, using which the method according to the present invention is to be explained. The region identified with A shows curves when the driver of the vehicle brakes only lightly, while the region identified with B shows curves in the event of strong braking.
In region A, engine speed 1 of engine 10 and transmission input shaft speed 2 of transmission 12 run largely uniformly and fall slightly due to the light braking action on brake 14 . Clutch torque 3 of clutch 16 also falls slightly, while engine torque 4 of engine 10 increases slightly. The clutch is closed and operates essentially without slip. This may be the situation when parking.
If the driver now actuates the brake more strongly, it is provided according to the present invention that clutch torque 3 is reduced with a higher gradient than is the case in the event of light braking, as shown in region A. The engine has reacted to the stronger braking during the creep drive mode with an increase in engine torque 4 , whereupon clutch torque 3 is reduced using increasing gradients. Through the braking action, engine speed 1 is reduced, but clutch torque 3 has already been reduced significantly more strongly. Transmission input shaft speed 2 falls significantly, and the engine no longer has a high braking torque applied to it. Since the rotational speed drop of the engine comes to an end, the engine no longer reacts with an increase in engine torque 4 , and torque curve 4 drops further.
Although the case of an initially light braking action followed by a stronger braking action is illustrated in FIG. 1 , the reverse case may also exist, in which the driver initially brakes more strongly and then reduces the braking force. In this case as well, the clutch torque is reduced with a higher gradient during the stronger braking action than during a lighter braking action.
FIG. 2 shows curves for a biting point of the clutch that has been established too low by the controller. The region with a gray background shows that engine speed 1 falls greatly and the engine reacts with a significant increase in engine torque 4 and attempts to compensate for the drop. Clutch torque 3 has already been significantly reduced, the clutch slips, and engine torque 4 nonetheless rises. The biting point used by the controller of the clutch as the setpoint biting point is too low and is to be shifted in the direction of an open clutch.
FIG. 3 shows curves in the event of a biting point of the clutch that has been established too high by the controller. The region with the gray background shows that engine speed 1 remains unchanged in the adaptation time, i.e., the clutch is already open too far. The controller of the clutch has therefore set a setpoint biting point that is too high. The new setpoint biting point of the clutch is therefore to be shifted in the direction of a closed clutch.
Finally, FIG. 4 of the drawing shows a diagram with the curve of the clutch torque in the creep drive mode. The creep torque may be between 10 Nm and 15 Nm, depending on the vehicle, and is high enough that the vehicle moves at a low speed. The creep torque is set at the clutch if the first gear, the second gear, or the reverse gear is engaged, the brake is not actuated, and the accelerator pedal is also not actuated.
The method provided according to the present invention thus differs from the method previously described having ramped buildup to the biting point in that a clutch torque which is a function of the strength of the actuation of the brake is built up in such a way that the creep torque is already set starting from a specific threshold value, i.e., the clutch is already somewhat closed starting from the threshold value. Therefore, according to the present invention, the signal indicating the strength of the actuation of the brake is filtered in order to take possible signal noise into consideration.
Creep torque 5 is changed as a function of the operating parameter of brake pressure in the example shown in FIG. 4 , in such a way that it is built up even at a still existing filtered brake pressure 6 , which results from brake pressure 7 . Therefore, a significantly better ability to meter the creep torque is achieved than was the case in the previous ramped buildup of the creep torque, in which the creep torque was first built up when the brake light switch of the vehicle signaled release of the brake. Through the buildup of the creep torque as a function of the brake pressure, it is possible to approach the curb comfortably when the vehicle is on a slope.
Instead of the operating parameter of brake pressure or the strength of the actuation of the brake, a gradient thereof may also be used as a parameter for the change in the clutch torque. Thus, for example, the clutch torque may be increased rapidly if the brake pressure gradient is high and the driver initiates a gear change action, since it may be assumed therefrom that the driver wishes to use the engine drag torque for braking.
Besides the signal representing the strength of the actuation of the brake, the digital brake light switch signal is also still available for analysis. This may be transmitted to the control unit via the CAN (controller area network) bus of the vehicle. If there is a further redundant brake light switch signal, a plausibility check of the signal may be performed and a source of error may be concluded in such a way that if there is no brake light switch signal transmitted outside the CAN bus, for example, a line interruption may be concluded. In the event of an implausible CAN signal, a defective control unit may be concluded, while in the event of an implausible brake pressure signal, a defect of the brake pressure sensor may be concluded.
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A method for altering the coupling torque of a coupling in the drive train of a vehicle with an automatic gearbox and/or automatic coupling in a creep drive mode of a vehicle. According to the invention, the coupling torque is altered according to at least one variable, the parameter of the vehicle describing the creep drive mode thereof.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of U.S. patent application Ser. No. 13/061,802, which is a U.S. National Phase Application based on International Application No. PCT/US2012/056222, filed Sep. 8, 2009, which claims the benefit of, and priority to, U.S. Provisional Patent Application Ser. Nos. 61/095,541, filed on Sep. 9, 2008. The disclosure of all applications are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to the preparation of modified polymers by chemically incorporating a compositional modifier into a polymer chain to produce the modified polymer. More particularly, the invention relates to the preparation of condensation type copolyesters by joining short length polyester or polyester oligomers with a modifier which contains hydroxyl acids blocks.
BACKGROUND OF THE INVENTION
Condensation polymers such as thermoplastic polyesters, polycarbonates, and polyamides have many desirable physical and chemical attributes that make them useful for a wide variety of molded, fiber, and film applications. However, for specific applications, these polymers also exhibit limitations that should be minimized or eliminated. To overcome these limitations, polymers are frequently made containing one or more additives or comonomers depending upon the desired end use of the polymer. One of the most common thermoplastic polyester polymers is polyethylene terephthalate (PET).
PET polymer is used extensively in the packaging industry, especially in the production of bottles for carbonated and non-carbonated beverages. In the carbonated beverage industry, concerns include the rate of carbon dioxide escape from the container, taste deterioration of the contents due to degradation by light, and extraction of additives added either during melt polymerization or subsequent melt processing that is required to fabricate the container. To overcome these problems, PET resins are often modified by incorporating unique comonomers into the polymer backbone thus producing a wide variety of PET copolyesters. For example, 2,6-naphthalenedicarboxylate (2,6-NDC) is copolymerized with ethylene glycol (EG) and terephthalic acid (TPA), propylene glycol is copolymerized with ethylene glycol (EG) and terephthalic acid (TPA) (U.S. Pat. No. 6,313,235), and isophthalic acid (IPA) is copolymerized with ethylene glycol (EG) and terephthalic acid (TPA) (U.S. Pat. Nos. 7,297,721, 6,489,434, and 6,913,806).
Condensation polymers may be degraded by hydrolysis with catalyst of acid, or base. The rate of depolymerization depends upon the structure of the polymers. Poly(hydroxyl acids), such as poly glycolic acid or poly lactic acid or copolymers of glycolic acid and lactic acid are easily hydrolyzed at mild conditions, even at pH 7 and room temperature in several months. Therefore, poly(hydroxyl acids) have wide applications based on their degradability, such as in medical devices and drug delivery system. On the other hand, polyethylene terephthalate (PET) hydrolyzes very slowly at mild conditions. To decompose such kind of polyester will require high temperature and high pressure through reaction with methanol, ethylene glycol or ammonia/glycol, which all involves organic solvents. PET and its derivatives have also wide applications based on their non-degradability and mechanical strength, such as fibers, packaging bottles and films.
Although there are many attempts to modify condensation polymers for extension of their application as described above, no attempts have been reported to incorporate degradable blocks of polyester into non-degradable condensation polyester in which the degradable blocks are uniformly distributed in the polymer chains.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a polymer comprising non-degradable blocks and degradable blocks. In some embodiments, the polymer has a structure of Formulae (Ia) or (Ib):
wherein t, m, p, q, r are integers other than zero, n is integers includes zero, R, R 1 , R 2 , R 3 , R 4 , R″ are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol. In some embodiments, the R, R 1 , R 2 , R 3 , R 4 , R″ are independently C 1 -C 10 alkyls.
In some embodiments, the degradable blocks has a structure according to Formula (III)
wherein t, m, n are integers other than zero, X is Cl, Br, I, NH 2 —, HO—, R′OCO—C 6 H 4 —COO— (where R′ is H, CH 3 , C 2 H 5 or any other alkyls) or other polymer chains and R, R 1 , R 2 are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments, the degradable blocks has a structure according to Formula (IV):
wherein t, m, n are integers, R, R 1 , R 2 , arealkyls (CH 3 , C 2 H 5 . . . ), R″ is any substitute groups, and R′ is H or alkyls.
In another aspect, the present invention provides a degradable segment according to Formula (III):
wherein t, m, n are integers other than zero, X is Cl, Br, I, NH 2 —, HO—, R′OCO—C 6 H 4 —COO— (where R′ is H, CH 3 , C 2 H 5 or any other alkyls) or other polymer chains and R, R 1 , R 2 are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol. In some embodiments the degradable segment is made according to Scheme Ia:
In another aspect, the present invention provides a degradable segment according to Formula (IV):
wherein t, m, n are integers, R, R 1 , R 2 are alkyls (CH 3 , C 2 H 5 . . . ), R″ is any substitute groups, and R′ is H or alkyls. In some embodiments the degradable segment is made according to Scheme Ib:
In another aspect, the present invention provides a method of making a polymer comprising degradable blocks and non-degradable blocks, said method comprises the steps of: (a) synthesizing degradable hydroxyl acids blocks; (b) polymerizing non degradable polymer monomer or pre polymer with degradable hydroxyl acids blocks to form said polymers in a solution polymerization process or melting polymerization process.
In another aspect, the present invention provides a method of making a polymer comprising degradable blocks and non-degradable blocks, said method comprises the steps of: (a) synthesizing degradable hydroxyl acids blocks; (b) synthesizing non-degradable polymers; and (c) joining said non-degradable blocks with and said degradable polymers in a solution polymerization process or melting polymerization process.
In some embodiments of the method provided herein, the polymer has the structure according to Formulae (Ia) or (Ib):
wherein t, m, n, p, q are integers other than zero, R, R 1 , R 2 , R 3 , R 4 , R″ are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments of the method provided herein the degradable blocks have the structure according to Formula (II):
wherein t, m are integers; X is Cl, Br, I, NH 2 —, or HO—, R′OCO—C 6 H 4 —COO— (where R′ is H, CH 3 , C 2 H 5 or any other alkyls) and R is H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol, or Formula (III):
wherein t, m, n are integers other than zero, X is Cl, Br, I, NH 2 —, HO—, R′OCO—C 6 H 4 —COO— (where R′ is H, CH 3 , C 2 H 5 or any other alkyls), and R, R 1 , R 2 are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments of the method provided herein, the degradable blocks are diol. In some embodiments, the non-degradable blocks are esters. In some embodiments, the degradable blocks have the structure according to Formula (IV):
wherein t, m, n are integers, X is Cl, Br, I, NH 2 —, HO—, R is alkyls (CH 3 , C 2 H 5 . . . ), R″ is any substitute groups, and R′ is H or alkyls.
In some embodiments of the method provided herein, the step (a) is carried out according to Scheme (Ia):
In some embodiments of the method provided herein, the step (a) is carried out according to Scheme (II):
In some embodiments of the method provided herein, the step (c) is carried out according to Scheme (IV):
In some embodiments of the method provided herein, the degradable and non-degradable blocks comprise carbonyl chloride ends and said carbonyl chloride are converted into carboxylic acid before said step (c).
DETAILED DESCRIPTION OF THE INVENTION
I. Definitions and Abbreviations
Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Generally, the nomenclature used herein and the laboratory procedures in cell culture, molecular genetics, organic chemistry and nucleic acid chemistry and hybridization are those well known and commonly employed in the art. Standard techniques are used for nucleic acid and peptide synthesis. The techniques and procedures are generally performed according to conventional methods in the art and various general references, which are provided throughout this document. The nomenclature used herein and the laboratory procedures in analytical chemistry, and organic synthetic described below are those well known and commonly employed in the art. Standard techniques, or modifications thereof, are used for chemical syntheses and chemical analyses.
The term “alkyl,” by itself or as part of another substituent, means, unless otherwise stated, a straight or branched chain, or cyclic hydrocarbon radical, or combination thereof, which may be fully saturated, mono- or polyunsaturated and can include di- and multivalent radicals, having the number of carbon atoms designated (i.e. C 1 -C 10 means one to ten carbons). Examples of saturated hydrocarbon radicals include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, cyclohexyl, (cyclohexyl)methyl, cyclopropylmethyl, homologs and isomers of, for example, n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like. An unsaturated alkyl group is one having one or more double bonds or triple bonds. Examples of unsaturated alkyl groups include, but are not limited to, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and the higher homologs and isomers. The term “alkyl,” unless otherwise noted, is also meant to include those derivatives of alkyl defined in more detail below, such as “heteroalkyl.” Alkyl groups, which are limited to hydrocarbon groups, are termed “homoalkyl”.
The term “alkylene” by itself or as part of another substituent means a divalent radical derived from an alkane, as exemplified, but not limited, by —CH 2 CH 2 CH 2 CH 2 —, and further includes those groups described below as “heteroalkylene.” Typically, an alkyl (or alkylene) group will have from 1 to 24 carbon atoms, with those groups having 10 or fewer carbon atoms being preferred in the present invention. A “lower alkyl” or “lower alkylene” is a shorter chain alkyl or alkylene group, generally having eight or fewer carbon atoms.
The terms “alkoxy,” “alkylamino” and “alkylthio” (or thioalkoxy) are used in their conventional sense, and refer to those alkyl groups attached to the remainder of the molecule via an oxygen atom, an amino group, or a sulfur atom, respectively.
The term “heteroalkyl,” by itself or in combination with another term, means, unless otherwise stated, a stable straight or branched chain, or cyclic hydrocarbon radical, or combinations thereof, consisting of the stated number of carbon atoms and at least one heteroatom selected from the group consisting of O, N, Si and S, and wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen heteroatom may optionally be quaternized. The heteroatom(s) O, N and S and Si may be placed at any interior position of the heteroalkyl group or at the position at which the alkyl group is attached to the remainder of the molecule. Examples include, but are not limited to, —CH 2 —CH 2 —O—CH 3 , —CH 2 —CH 2 —NH—CH 3 , —CH 2 —CH 2 —N(CH 3 )—CH 3 , —CH 2 —S—CH 2 —CH 3 , —CH 2 —CH 2 , —S(O)—CH 3 , —CH 2 —CH 2 , —S(O) 2 —CH 3 , —CH═CH—O—CH 3 , —Si(CH 3 ) 3 , —CH 2 —CH═N—OCH 3 , and —CH═CH—N(CH 3 )—CH 3 . Up to two heteroatoms may be consecutive, such as, for example, —CH 2 —NH—OCH 3 and —CH 2 —O—Si(CH 3 ) 3 . Similarly, the term “heteroalkylene” by itself or as part of another substituent means a divalent radical derived from heteroalkyl, as exemplified, but not limited by, —CH 2 —CH 2 —S—CH 2 —CH 2 — and —CH 2 —S—CH 2 —CH 2 —NH—CH 2 —. For heteroalkylene groups, heteroatoms can also occupy either or both of the chain termini (e.g., alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, and the like). Still further, for alkylene and heteroalkylene linking groups, no orientation of the linking group is implied by the direction in which the formula of the linking group is written. For example, the formula —C(O) 2 R′— represents both —C(O) 2 R′— and —R′C(O) 2 —.
In general, an “acyl substituent” is also selected from the group set forth above. As used herein, the term “acyl substituent” refers to groups attached to, and fulfilling the valence of a carbonyl carbon that is either directly or indirectly attached to the polycyclic nucleus of the compounds of the present invention.
The terms “cycloalkyl” and “heterocycloalkyl”, by themselves or in combination with other terms, represent, unless otherwise stated, cyclic versions of “alkyl” and “heteroalkyl”, respectively. Additionally, for heterocycloalkyl, a heteroatom can occupy the position at which the heterocycle is attached to the remainder of the molecule. Examples of cycloalkyl include, but are not limited to, cyclopentyl, cyclohexyl, 1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like. Examples of heterocycloalkyl include, but are not limited to, 1-(1,2,5,6-tetrahydropyridyl), 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-morpholinyl, 3-morpholinyl, tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, tetrahydrothien-2-yl, tetrahydrothien-3-yl, 1-piperazinyl, 2-piperazinyl, and the like.
The terms “halo” or “halogen,” by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom. Additionally, terms such as “haloalkyl,” are meant to include monohaloalkyl and polyhaloalkyl. For example, the term “halo(C 1 -C 4 )alkyl” is mean to include, but not be limited to, trifluoromethyl, 2,2,2-trifluoroethyl, 4-chlorobutyl, 3-bromopropyl, and the like.
The term “aryl” means, unless otherwise stated, a polyunsaturated, aromatic, hydrocarbon substituent, which can be a single ring or multiple rings (preferably from 1 to 3 rings), which are fused together or linked covalently. The term “heteroaryl” refers to aryl groups (or rings) that contain from one to four heteroatoms selected from N, O, and S, wherein the nitrogen and sulfur atoms are optionally oxidized, and the nitrogen atom(s) are optionally quaternized. A heteroaryl group can be attached to the remainder of the molecule through a heteroatom. Non-limiting examples of aryl and heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 3-pyrazolyl, 2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl, 2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 4-pyrimidyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl, 5-indolyl, 1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 3-quinolyl, and 6-quinolyl. Substituents for each of the above noted aryl and heteroaryl ring systems are selected from the group of acceptable substituents described below.
For brevity, the term “aryl” when used in combination with other terms (e.g., aryloxy, arylthioxy, arylalkyl) includes both aryl and heteroaryl rings as defined above. Thus, the term “arylalkyl” is meant to include those radicals in which an aryl group is attached to an alkyl group (e.g., benzyl, phenethyl, pyridylmethyl and the like) including those alkyl groups in which a carbon atom (e.g., a methylene group) has been replaced by, for example, an oxygen atom (e.g., phenoxymethyl, 2-pyridyloxymethyl, 3-(1-naphthyloxy)propyl, and the like).
Each of the above terms (e.g., “alkyl,” “heteroalkyl,” “aryl” and “heteroaryl”) include both substituted and unsubstituted forms of the indicated radical. Preferred substituents for each type of radical are provided below.
Substituents for the alkyl, and heteroalkyl radicals (including those groups often referred to as alkylene, alkenyl, heteroalkylene, heteroalkenyl, alkynyl, cycloalkyl, heterocycloalkyl, cycloalkenyl, and heterocycloalkenyl) are generally referred to as “alkyl substituents” and “heteroalkyl substituents,” respectively, and they can be one or more of a variety of groups selected from, but not limited to: —OR′, ═O, ═NR′, ═N—OR′, —NR′R″, —SR′, -halogen, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO 2 R′, —CONR′R″, —OC(O)NR′R″, —NR″C(O)R′, —NR′—C(O)NR″R′″, —NR″C(O) 2 R′, —NR—C(NR′R″R′″)═NR″″, —NR—C(NR′R″)═NR′″, —S(O)R′, —S(O) 2 R′, —S(O) 2 NR′R″, —NRSO 2 R′, —CN and —NO 2 in a number ranging from zero to (2 m′+1), where m′ is the total number of carbon atoms in such radical. R′, R″, R′″ and R″″ each preferably independently refer to hydrogen, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, e.g., aryl substituted with 1-3 halogens, substituted or unsubstituted alkyl, alkoxy or thioalkoxy groups, or arylalkyl groups. When a compound of the invention includes more than one R group, for example, each of the R groups is independently selected as are each R′, R″, R′″ and R″″ groups when more than one of these groups is present. When R′ and R″ are attached to the same nitrogen atom, they can be combined with the nitrogen atom to form a 5-, 6-, or 7-membered ring. For example, —NR′R″ is meant to include, but not be limited to, 1-pyrrolidinyl and 4-morpholinyl. From the above discussion of substituents, one of skill in the art will understand that the term “alkyl” is meant to include groups including carbon atoms bound to groups other than hydrogen groups, such as haloalkyl (e.g., —CF 3 and —CH 2 CF 3 ) and acyl (e.g., —C(O)CH 3 , —C(O)CF 3 , —C(O)CH 2 OCH 3 , and the like).
Similar to the substituents described for the alkyl radical, the aryl substituents and heteroaryl substituents are generally referred to as “aryl substituents” and “heteroaryl substituents,” respectively and are varied and selected from, for example: halogen, —OR′, ═O, ═NR′, ═N—OR′, —NR′R″, —SR′, -halogen, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO 2 R′, —CONR′R″, —OC(O)NR′R″, —NR″C(O)R′, —NR′—C(O)NR″R′″, —NR″C(O) 2 R′, —NR—C(NR′R″)═NR′″, —S(O)R′, —S(O) 2 R′, —S(O) 2 NR′R″, —NRSO 2 R′, —CN and —NO 2 , —R′, —N 3 , —CH(Ph) 2 , fluoro(C 1 -C 4 )alkoxy, and fluoro(C 1 -C 4 )alkyl, in a number ranging from zero to the total number of open valences on the aromatic ring system; and where R′, R″, R′″ and R″″ are preferably independently selected from hydrogen, (C 1 -C 8 )alkyl and heteroalkyl, unsubstituted aryl and heteroaryl, (unsubstituted aryl)-(C 1 -C 4 )alkyl, and (unsubstituted aryl)oxy-(C 1 -C 4 )alkyl. When a compound of the invention includes more than one R group, for example, each of the R groups is independently selected as are each R′, R″, R′″ and R″″ groups when more than one of these groups is present.
Two of the aryl substituents on adjacent atoms of the aryl or heteroaryl ring may optionally be replaced with a substituent of the formula -T-C(O)—(CRR′) q —U—, wherein T and U are independently —NR—, —O—, —CRR′— or a single bond, and q is an integer of from 0 to 3. Alternatively, two of the substituents on adjacent atoms of the aryl or heteroaryl ring may optionally be replaced with a substituent of the formula -A-(CH 2 ) r —B—, wherein A and B are independently —CRR′—, —O—, —NR—, —S—, —S(O)—, —S(O) 2 —, —S(O) 2 NR′— or a single bond, and r is an integer of from 1 to 4. One of the single bonds of the new ring so formed may optionally be replaced with a double bond. Alternatively, two of the substituents on adjacent atoms of the aryl or heteroaryl ring may optionally be replaced with a substituent of the formula —(CRR′) s —X—(CR″R′″) d —, where s and d are independently integers of from 0 to 3, and X is —O—, —NR′—, —S—, —S(O)—, —S(O) 2 —, or —S(O) 2 NR′—. The substituents R, R′, R″ and R′″ are preferably independently selected from hydrogen or substituted or unsubstituted (C 1 -C 6 ) alkyl.
As used herein, the term “heteroatom” includes oxygen (O), nitrogen (N), sulfur (S), phosphorus (P) and silicon (Si).
II. The Compositions
In one aspect, the present invention provides condensation polymers comprising degradable blocks of short chain length of poly hydroxyl acids as joints of non-degradable polymer chains. In general, such polymers retains the mechanical strength of non-degradable blocks (the major blocks of the polymer) but are easily degraded at their degradable blocks (the location of joints) and therefore the long chain polymers will be degraded back to non-degradable short chains.
In some embodiments, the present invention provides degradable blocks or degradable segments having the structure according to Formula (III):
wherein t, m, n are integers; X is Cl, Br, I, NH 2 —, HO—, R′OCO—C 6 H 4 —COO— (where R′ is H, CH 3 , C 2 H 5 or any other alkyls) or other polymer chains, and R 1 , R 2 are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol. In some embodiments, X is removed when incorporated into polymers.
In some embodiments, the present invention provides degradable blocks or degradable segments having the structure according to Formula (IV):
wherein t, m, n are integers; R, R 1 , R 2 are alkyls (CH 3 , C 2 H 5 . . . ); R′ is H or alkyls (CH 3 , C 2 H 5 . . . ); R″ is any substitute groups; and R′ is H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments, the non-degradable blocks are polyester (exclude the polyhydroxyl acids, which are degradable), with functional groups to react with degradable short chains. By “non-degradable” herein is meant that the rate of hydrolysis is much slower then that of polyhydroxy acids, rather than absolutely no degradation.
In one aspect, the present invention provides non-degradable polymers with degradable blocks. These polymers comprise of both degradable blocks and non-degradable blocks such as Formulae (Ia) and (IIb):
wherein t, m, n, p, q are integers; R, R 1 , R 2 , R 3 , R 4 , R″ are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments, R, R 1 , R 2 , R″ are independently C 1 to C 10 alkyls.
In some embodiments, the degradable blocks are short chain poly hydroxyacids with functional groups at both ends to react with non degradable-blocks.
In some embodiments, the polymers comprise degradable blocks according to Formulae (IIIa):
wherein t, m, n are integers; and R, R 1 , R 2 are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments, the polymers comprise degradable blocks according to Formulae (IV):
wherein t, m, n are integers; R, R 1 , R 2 , are alkyls (CH 3 , C 2 H 5 . . . ); R″ is any substitute groups; and R′ is H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
The ratio between the non-degradable blocks and the degradable blocks in the polymers can vary. In some embodiments, the polymers comprises non-degradable blocks as major components (from 50% to 100% weight percentage) and degradable blocks as minor components (from 0% to 50% weight percentage).
III. Method of Making
In another aspect, the present invention provides methods of manufacturing polymers.
The method of manufacturing polymers with degradable blocks in present invention comprises three major modules: (a) synthesis of degradable hydroxyl acids blocks, (b) synthesis of non-degradable polymers, and (c) joining both degradable blocks and non degradable polymers together.
(a). Synthesis of Degradable Hydroxyl Acids Blocks
In one aspect, the present invention provides methods of synthesizing degradable hydroxyl acids blocks, such as the process in Scheme Ia or Ib:
In some embodiments, a poly hydroxyl acids oligomer according to Formula (II) is first synthesized according to Huang's methods (U.S. Application No. 61/054,218) and/or Hermes and Huang's method (U.S. Pat. No. 5,349,047), both are herein incorporated by reference in their entirety. Formula (II):
wherein t, m are integers; X is Cl, Br, I, NH 2 —, or HO—, R′OCO—C 6 H 4 —COO— (where R′ is H, CH 3 , C 2 H 5 or any other alkyls), and R is H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiments, R is C 1 to C 10 alkyls.
The poly hydroxyl acids oligomer then reacts with ethylene glycol (EG) to form a new oligomer with both ends of halide, hydroxy or amine (Formula (III)) (Scheme I) or with terephthalic acid (TPA) to form a new oligomer with both ends of carboxylic acids or carboxylate esters (Formula (IV)) (Scheme II).
The poly hydroxyl acids oligomer halide then reacts with ethylene glycol (EG) to form a new oligomer with end of hydroxy or which then reacts with terephthalic acid (TPA) to form a new oligomer with both ends of carboxylic acids or carboxylate esters (Formula (IV)) (Scheme IIa).
The reaction of oligomer with diol or dicarboxylic acid involved here is esterification reaction which can be accomplished by react carbonyl chloride of polyhydroxyl acid oligomers (Formula (V)) with ethylene glycol or directly react the carboxylic acid group of oligomer to ethylene glycol with acid catalysts of ion exchange resin. In the case of oligomer reacting to terephthalic acid (TPA), it can be accomplished by reacting TPA with halocarboxylic acid oligomer and amines such as triethylamine or ethyldiisopropylamine.
In some embodiments, the polyhydroxyl acid oligomers have the structure according to Formula (V):
wherein t, m are integers; X is Cl, Br, I, NH 2 —, or HO—; and R is substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiment, glycol contained degradable blocks (Formula (III)) is reacted with TPA or terephthalate according to the Scheme III to form the blocks with carboxylic acid or carboxylate at both ends (Formula (IIIb):
wherein t, m, n are integers; R′ is H, CH 3 , C 2 H 5 or any alkyls, R, R 1 , R 2 are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
(b). Synthesis of Non-Degradable Polymers
The non-degradable blocks, such as polyester (exclude the polyhydroxyl acids, which are degradable), polycarbonate or polyamide are synthesized according to methods known in the art. In general, the non-degradable blocks have functional hydroxyl group at the ends of polymer chains (generally with very small amount of carboxylic acid as the end group), which are reactive with degradable short chains.
To control the molecular weight or degree of polymerization of non-degradable polymer blocks, the time and pressure of traditional melting process can be adjusted. The alternative way is to react terephthaloyl chloride with diol in various ratio for two different monomers to control the degree of polymerization (DP) and the end group (hydroxyl ended or carbonyl chloride ended).
In some embodiment, the non-degradable blocks have the structure according to Formula (VI):
wherein n is an integer other than zero, R 1 , R 2 and R″ are members independently selected in each structural units from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, ester, nitro, amine, amide, or thiol.
In some embodiment, the end group of the non-degradable blocks need to be modified into carboxylic acid, if the blocks will be joined with Formula (III). Scheme IV shows the reaction of the modification:
The solvent used in this reaction is 1,1,2,2-tetrachloroethane or any other suitable organic solvent which can dissolve the non-degradable blocks at reflux temperature or below.
In case of carbonyl chloride ended blocks, direct hydrolysis converts carbonyl chloride into carboxylic acid.
(c). Joining Both Degradable Blocks and Non-Degradable Polymers
In another aspect, the present invention provides methods for joining non-degradable polymers with degradable blocks together to obtain high molecular weight polymers.
In conventional polyester manufacturing, copolyesters are typically produced by two different routes: ester exchange plus polycondensation (the DMT process) or direct esterification plus polycondensation (the direct esterification process). Either of these routes comprises two stages: In the first stage a polymer ester is formed by polymerization the monomers at about 180° C. to 230° C. The second stage, referred as post polymerization reaction, is carried out at a higher temperature (280° C.) or other process to obtain higher molecular weight polyester.
Instead of move on to second stage, the present invention utilizes the degradable blocks to join the polyesters produced in the first stage directly.
In some embodiments, when non-degradable blocks are ended with hydroxyl group from the melting reaction process, carboxylic acid or carboxylate ended degradable blocks (formula IIIA, formula IV) can be added into the reactor of melting process directly at beginning or middle of the reaction. To ensure the degradable blocks are uniformly distributed in the overall polymer chains, the non-degradable blocks are generally synthesized first with commercial melting process of polycondensation (e.g. 2˜4 hours at 275° C. under vacuum and then the degradable blocks is added and the reaction continues at 275° C. for another 2˜4 hours under vacuum.) Scheme V shows one of example reaction in this process when the byproduct H 2 O is removed under vacuum. Similar ester exchange reactions can be carried out in the melting polymerization by removal of alcohols under vacuum.
If the distribution of degradable blocks in the final polymer chains is not a concern, the degradable blocks generally can be added to monomers of non-degradable polymer at the beginning to form degradable blocks contained polymer through mature industrial PET manufacture process, such as those shown in Scheme VI. The distribution of degradable blocks in polymers obtained with such approach will be random but will still degradable at their degradable blocks when they are exposed to proper environments such as basic solution.
In some embodiments, the joint degradable segment is not ended with carboxylic acid and therefore we need to convert the end groups of non-degradable blocks as described herein.
The joining reactions here again are esterification process. Although there are many possible processes to esterification, a very convenient method is to follow the reactions between α-halocarboxylate and carboxylic acid as disclosed in Huang's method (U.S. Patent Application No. 61/054,218), the disclosure of which is incorporated by reference in its entirety. In order to obtain high molecular weight polymer, the stoichiometry between two reactants, the degradable blocks and short chain non-degradable polymers with carboxylic acid as end group here, must be controlled very well.
Generally, it is difficulty to calculate the stoichiometry of short chain non-degradable polymers because of the length diversity of polymer chain. However, due to the acidic end groups in short chain polymers, through titration of the content of acid groups in the polymer solution, we can finger out the acid equivalents per gram and therefore know exactly how much degradable halo blocks we need to form longer co-polymer.
IV. Applications
The polymers provided herein can find use in a variety of applications, such as packaging bottles for beverages, food packing films, shopping bags and other containers.
It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference for all purposes.
EXAMPLES
Example 1
Synthesis of ethylene di-bromoacetylate. To a solution of bromoacetyl chloride (TCI, 95 gram, 0.6 mole) in 100 ml dry ethyl acetate was added dropewisely anhydrous ethylene glycol (Sigma-Aldrich, 12.41 gram, 0.2 mole). The solution was stirred at 70° C. under N 2 protection for 16 hours and then washed with 200 ml DI water and 200 ml brine. The solvent was removed in vacuum after drying with anhydrous MgSO 4 . The crude product was vacuum pumper for 24 hours and then vacuum distilled. ˜100° C./3 mm Hg fraction was collected. 35 gram product was obtained, yield 58%. 1 HNMR (CDCl 3 , 400 Mz) δ 4.365 (S, 4H); δ 3.830 (S, 4H).
Example 2
Synthesis of ethylene di-bromoacetylate(BrGEGBr). To a 250 ml round bottom flask were placed bromoacetic acid (Sigma-Aldrich, 69.5 g, 0.5 mole), ethylene glycol (Sigma-Aldrich, 15.44 g, 0.25 mole), Dowex C-211, H + form cation ion exchange resin (4 g) and benzene (100 ml). The mixture was refluxed with Dean Stark Trap for 16 hours, record water trapped. When there was no more water come out, the solution was cool down to room temperature and the resin was filtrated out. Water was measured (8.5 ml). The solvent benzene was removed in vacuum. The product was vacuum distilled at about 3 mm Hg, ˜100 C/3 mm Hg fraction was collected (40 g), yield 53%. 1 HNMR (CDCl 3 , 400 Mz) δ 4.365 (S, 4H); δ 3.830 (S, 4H).
Example 3
Synthesis of bromoacetylate glycolic acid (BrGG acid). To a 250 ml round bottom flask were placed bromoacetic acid (Sigma-Aldrich, 69.5 g, 0.5 mole), glycolic acid (Sigma-Aldrich, 37.52 g, 0.5 mole), Dowex C-211, H + form cation ion exchange resin (4 g) and benzene (100 ml). The mixture was refluxed with Dean Stark Trap for 13 hours, record water trapped. When there was no more water come out, the solution is cool down to room temperature and the resin is filtrated out. Water was measured (11 ml). The solvent benzene was removed in vacuum. The product was vacuum distilled at about 3 mm Hg, 105˜108° C./3 mm Hg fraction was collected (12.9 g), yield 13.1% (the major product were poly glycolic acid oligomers). 1 HNMR (CDCl 3 , 400 Mz) δ 4.850 (S, 2H); δ 3.950 (S, 2H).
Example 4
Synthesis of Ethylene Bromoacetylate Glycolate (BrGGEGGBr)
To a 250 ml round bottom flask were placed BrGG acid (from Example III, 29.55 g, 0.15 mole), ethylene glycol (Sigma-Aldrich, 7.45 g, 0.12 mole), Dowex C-211, H + form cation ion exchange resin (4 g) and benzene (100 ml). The mixture was refluxed with Dean Stark Trap for 16 hours, record water trapped. When there was no more water come out, the solution was cool down to room temperature and the resin was filtrated out. Water was measured (4.3 ml). The filtrate solution is washed with Sat. NaHCO 3 aq solution (100 ml) to remove excess BrGG. The solvent benzene was removed in vacuum after dried with MgSO4.
Example 5
Synthesis of PET Oligomer
To a 250 ml two neck round bottom flask equipped with condenser are placed terephthalic acid chloride (64.015 g, 98%, 0.309 mole) and 150 ml toluene, ethylene glycol (18.658 g, 99.8%, 0.3 mole) in 50 ml toluene is dropwisely added at 80° C. (oil bath 100° C.). After completion of addition, the mixture is refluxed under N 2 for 16 hours. The solvent is removed in vacuum and the residues are heated to 120° C. under vacuum for 3 hours. The residues are stirred with H 2 O (400 ml) for 3 hours, check pH value shows acidic. The solid product is filtrated and dried at 120° C. overnight.
Example 6
Synthesis of PET Oligomer
To a 250 ml stainless steel bomb are placed Bis(2-hydroxyethyl)terephthalate (BHET, Sigma-Aldrich, 30 g, 0.118 mole), 350 ppm Sb2O3 (Alfa Aesar) and a magnetic stirring bar. The system is purged with N2/Vacuum three times and then typically heated to 275° C. in 30 min. The System is kept at 275° C. under vacuum (3 mm Hg) for a time period from 2˜5 hours. The bomb is then opened and dry ice is added into the bomb to cool down the melt to room temperature quickly. The bulk solid is roughly grinded into small pieces and the viscosity is measured in phenol/1,1,2,2-tetrachloroethane (60/40 weight ratio) according to SPI's (The Society of Plastic Industry) standard PET measurement procedure. The Table 1 summarized the IV (intrinsic viscosity) for various reaction times.
Time of
Reaction (min)
IV
120
0.08
150
0.12
180
0.18
240
0.43
Example 7
Conversion the End Group of PET Oligomers into Carboxylic Acid
PET oligomers (IV=0.12, 20 gram from Example 6) is placed in round bottom flask with 1,1,2,2-tetrachloroethane (Alfa Aesar, 100 ml) and Terephthaloyl chloride (sigma-Aldrich, 10 g). The solution is refluxed for 16 hours with stirring and then is cooled down to room temperature and diluted with 200 ml ethyl ether. The solid product is collected and dried after filtration, grinded and placed into DI water (400 ml) and 150 ml acetonitrile. The mixture is stirred for 5 hours and then pH is adjusted to 7˜8 with HCl and stirred for 1 more hour. The white solid is collected and dried at 120° C. for >3 hours after filtration.
Example 8
Synthesis of PET Polymers with GEG Blocks
To a solution of PET oligomer from Example V (11.088 g, 0.01 mole) and Et3N (2.0238 g, 0.02 mole) in 90 ml anhydrous acetonitrile is added dropwisely a solution of BrGEGBr (3.0394 g, 0.01 mole) in 10 ml anhydrous acetonitrile. The mixture is stirred at room temperature for 48 hours. The solution is poured into 500 ml DI water, stirred at room temperature for two hours, filtrated and dried at 110° C. overnight. 11.69 g product is obtained. Yield 93.5%.
Example 9
Synthesis of PET Polymers with GGEGG Blocks
To a solution of PET oligomer from Example 5 (11.088 g, 0.01 mole) and Et3N (2.0238 g, 0.02 mole) in 90 ml anhydrous acetonitrile is added dropwisely a solution of BrGGEGGBr (4.200 g, 0.01 mole) in 10 ml anhydrous acetonitrile. The mixture is stirred at room temperature for 48 hours. The solution is poured into 500 ml DI water, stirred at room temperature for two hours, filtrated and dried at 110° C. overnight.
Example 10
Synthesis of PET Polymers with Degradable Blocks
PET oligomers (IV=0.18, 20 gram from Example 6) and degradable blocks (repeat unit molar ration 10:1) are placed in the stainless steel bomb with a magnetic stirring bar and N2/vacuum purged three times. The system is placed in a 275° C. oil bath for 3 hours with stirring under vacuum. The bomb is then opened and added with dry ice to cool down the melt to room temperature quickly. The bulk solid is roughly grinded into small pieces and the viscosity is measured in phenol/1,1,2,2-tetrachloroethane (60/40 weight ratio) according to SPI's (The Society of Plastic Industry) standard PET measurement procedure. The Table 2 summarized the IV (intrinsic viscosity) for various reaction times.
Example 11
Synthesis of MeGTGMe (Formula (IV)
To a solution of TPA (Sigma-Aldrich, 33.9 g, 98%, 0.2 mole) and Et3N (40.4 g, 56 ml, 0.4 mole) in 300 ml anhydrous acetonitrile is added dropwisely a solution of methyl bromoacetate (Sigma-Aldrich, 62.44 g, 98%, 0.4 mole) in anhydrous acetonitrile (30 ml). The mixture is stirred at room temperature for 24 hours. The solution is then filtrated to remove the solid Et3N salt. The solvent in filtrate is removed in vacuum and the residues are washed (stirring in) with 1% HCl (500 ml), NaHCO3 sat aq solution (1000 ml) and washed with DI water. The white solid product (48.8 g) is collected after filtration and drying in oven (120° C.) overnight. Mp=107˜109° C. Yield 78%.
Example 12
Modification of degradable blocks (MeTGEGTMe). To a solution of mono-Methyl terephthalate (36.03 g, 0.2 mole) and BrGEGBr (30.4 g, 0.1 mole) in 150 ml anhydrous acetonitrile is added dropwisely triethylamine (20.24 g, 0.2 mole) in a period of one hour at room temperature. The solution was stirred for 20 hours and the white precipitate is filtered out and stirred with 1% HCl (150 ml), NaHCO 3 saturated aqueous solution (150 ml) for two hours respectively. The crude product was collected through filtration and dried at 120° C. overnight. The crude product was recrystallized in hot acetonitrile and 37.7 gram final product was collected, Mp167° C., yield 76%.
Example 13
Synthesis of PET with modified degradable blocks. To a 150 ml round flask was charged with MeTGEGTMe (14.83 g, 0.03 mole), BHET (7.63 g, 0.03 mole) and Sb 2 O 3 (0.03 gram). The mixture was heated to 200° C. under vacuum (20 mmHg) with stirring. The melt was kept at 200° C. for 7 hours and then poured into ice-water.
Example 14
Synthesis of ethylene glycol capped methyl glycolate. To a solution of ethylene glycol (18.62 g, 0.3 mole), ground NaOH (12 g, 0.3 mole) in anhydrous acetonitrile was added dropwisely methyl chloroacetate (32.56 g, 0.3 mole) at 0° C. in a period of 1 hour. The solution was stirred at 0° C. for another 7 hours and the solvent acetonitrile was removed in vacuum.
Example 15
Synthesis of MeGETEGMe. To a 250 ml round bottom flask were placed terephthalic acid (16.6 g, 0.10 mole), ethylene glycol capped methyl glycolate (26.83 g, 0.2 mole), Dowex C-211, H + form cation ion exchange resin (4 g) and benzene (100 ml). The mixture was refluxed with Dean Stark Trap for 16 hours, record water trapped. When there was no more water come out, the solution was cool down to room temperature and the resin was filtrated out. Water was measured (3.6 ml). The solvent benzene was removed in vacuum. The product was dissolved in ethyl acetate and washed with 1% HCl, saturated NaHCO 3 aqueous solution and saturated NaCl aqueous solution. The solvent was remove in vacuum and the solid crud product was collected.
Example 16
Polymerization of MeGETEGMe with BHET. Mixture of MeGETEGMe and BHET (1:1 molar ratio) and Sb 2 O 3 was melting polymerized according to previous examples. At the end of polymerization the polymer melt is poured into the ice-water for quick cooling process.
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The present invention relates to the preparation of modified polymers by incorporating a compositional modifier into a polymer to produce the modified polymer. More particularly, the invention relates the preparation of condensation type copolyesters or copolyamides by joint short length polyester or polyester oligomers or short length polyamide or polyamide oligomers with a modifier which contains hydroxyl acids blocks.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application No. 60/227,049 filed Aug. 21, 2000.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention.
[0003] The present invention relates generally to drill bits, and, more particularly, to multi-directional cutters for a fixed cutter, drillout bi-center bit.
[0004] 2. Description of the Related Art.
[0005] In the pursuit of drilling boreholes into the earth for the recovery of minerals, there are instances when it is desirable to drill a borehole with a diameter larger than the bit itself. Drill bits used to form these boreholes are generally known as bi-center type drill bits.
[0006] Bi-center drill bits are well known in the drilling industry. Various types of bi-center drill bits are described in U.S. Pat. Nos. 1,587,266, 1,758,773, 2,074,951, 2,953,354, 3,367,430, 4,408,669, 4,440,244, 4,635,738, 5,040,621, 5,052,503, 5,165,494, 5,678,644 and European Patent Application 0,058,061 all herein incorporated by reference.
[0007] Modern bi-center drill bits are typically used in difficult drilling applications where the earth formations are badly fractured, where there is hole swelling, where the borehole has a tendency to become spiraled, or in other situations where an oversize hole is desirable.
[0008] In these difficult drilling applications, the top portion of the well bore is often stabilized by setting and cementing casing. The cement, shoe, float, and related cementing hardware are then typically drilled out of the casing by a drill bit that is run into the casing for this purpose. Once the cement and related hardware are drilled out, the drillout bit is tripped out of the hole and a bi-center drill bit is run back into the borehole. Drilling then proceeds with the bi-center drill bit, which drills a hole into the formation below the casing with a diameter that is greater than the inside diameter of the casing.
[0009] To reduce drilling expenses, attempts have been made to drill the cement and related hardware out of the casing, and then drill the formation below the casing with a single bi-center drill bit. These attempts often resulted in heavy damage to both the casing and the bi-center drill bit.
[0010] The casing tends to be damaged by the gauge cutting elements mounted on the bi-center drill bit because inside the casing the pilot section of the bit is forced to orbit about its center, causing the gauge cutters to engage the casing. The forced orbiting action of the pilot section can also cause damage to the cutters on the leading face of the bi-center drill bit.
[0011] As is well known in fixed cutter drill bits, the cutting elements have cutting faces which are precisely oriented relative to the direction of travel of the cutter through the formation being drilled. However, cutters located in an area generally between the passthrough center and the drilling center of the bit face of drillout bi-center bits experience two different directions of travel as they drill. One direction of travel occurs when the bit is drilling out, and the other direction of travel occurs when the bit is drilling the full diameter borehole. The cutters which lie in line between the two centers, in fact, experience exactly opposite directions of travel.
[0012] As previously stated, this has caused severe damage to the cutters in this area in the past. The typical solution to this problem has been to leave this area of the face of the bit devoid of cutters. Unfortunately, in some bi-center bit designs, particularly bi-center bits with large differences between the passthrough diameter and the drilling diameter, leaving this region devoid of cutters may cause the drilling performance of the bit to suffer.
[0013] The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
SUMMARY OF INVENTION
[0014] In one aspect of the present invention, there is provided a drillout bi-center drill bit comprising a bit body with a first end adapted to be detachably secured to a drill string, a pilot section on a second, opposite end of the bit body and a reamer section intermediate the first and second ends. There is a first drilling center of rotation of the pilot section and a second passthrough center of rotation of the pilot section spaced apart from the first center of rotation by a non-zero distance D. There is also a first region of the pilot section centered about the first center of rotation having a radius D, a second region of the pilot section centered about the second center of rotation having a radius D, and a third region of the pilot section formed by the intersection of the first region and the second region. A cutting element is fixed on the bit body within the third region. The cutting element has a first cutting face generally oriented perpendicular to the direction of travel of the cutting element about the first center of rotation of the pilot section and a second cutting face generally oriented perpendicular to the direction of travel of the cutting element about the second center of rotation.
[0015] In another aspect of the present invention, there is provided a drillout bi-center drill bit comprising a bit body with a longitudinal axis and a first end adapted to be detachably secured to a drill string, a pilot section on a second, opposite end of the bit body and a reamer section intermediate the first and second ends. There is a first drilling center of rotation of the pilot section and a second passthrough center of rotation of the pilot section spaced apart from the first center of rotation by a non-zero distance D. There is a first region of the pilot section centered about the first center of rotation having a radius D, a second region of the pilot section centered about the second center of rotation having a radius D, and a third region of the pilot section formed by the intersection of the first region and the second region. There are a plurality of first cutters in the third region, with superhard cutting faces generally oriented perpendicular to the direction of travel of the cutting element about the first center of rotation, projecting a distance from the bit body. At least one second cutter is fixed on the bit body within the third region and projecting a distance from the bit body greater than the projection of the first cutters, with a cutting face oriented generally perpendicular to the direction of travel of the second cutter about the second center of rotation.
BRIEF DESCRIPTION OF DRAWINGS
[0016] The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:FIG. 1 provides a perspective view of a drillout bi-center drill bit in accordance with one embodiment of the present invention; FIGS. 2A, 2B and 2 C show side views perspectives of the drillout bi-center drill bit of FIG. 1; FIG. 3 shows an end view perspective of the drillout bi-center drill bit of FIG. 1; FIG. 4A shows an end view perspective of the drillout bi-center drill bit of FIG. 1 illustrating the iris shaped third region; FIG. 4B shows a simplified end view of the iris shaped third region of the drillout bi-center drill bit of FIG. 4A; FIGS. 5 - 7 show perspective views of various cutting elements that are mounted in the iris shaped third region on the drillout bi-center drill bit in accordance with the present invention; FIG. 8 is a partial end view of the face of the drillout bi-center drill bit showing an alternate cutter arrangement in accordance with another embodiment of the present invention; FIG. 9 shows a perspective view of a cutting element of the embodiment of the drillout bi-center drill bit of FIG. 8; FIG. 10 shows a perspective view of still another cutter arrangement in accordance with another embodiment of the present invention.
[0017] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0018] Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers” specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0019] Turning now to the drawings, and specifically referring to FIGS. 1, 2A, 2 B, and 2 C, a drillout bi-center drill bit 10 having multi-directional cutters is shown in accordance with one embodiment of the present invention. The drillout bi-center drill bit 10 has a longitudinal axis 11 upon which the drill bit 10 rotates, and a bit body 12 with a first end 14 adapted to be secured to a drill string (not shown) for driving the drill bit 10 . According to one embodiment, threads 16 may be used for coupling the drill bit 10 to the drill string. However, it will be appreciated to those of ordinary skill in the art that various other forms of attachment may be used in lieu of the threads 16 without departing from the spirit and scope of the present invention. At a second, opposite end of the bit body 12 is a pilot section 18 of the drillout bi-center drill bit 10 with an exposed drilling face 17 . A reamer section, shown generally by numeral 20 , is intermediate the first end 14 and the pilot section 18 of the bi-center drill bit 10 .
[0020] While in operation, the bit body 12 is rotated via the drill string by some external means while the drillout bi-center drill bit 10 is forced into the material being drilled. The rotation under load causes cutting elements 24 exposed at the drilling face 17 to penetrate into the drilled material and remove the material in a scraping and/or gouging fashion.
[0021] In accordance with one embodiment of the present invention, the bit body 12 includes internal passaging (not shown) that allows pressurized drilling fluid to be supplied from the drilling surface to a plurality of nozzle orifices 22 . These nozzle orifices 22 discharge the drilling fluid to clean and cool the cutting elements 24 as they engage the material being drilled. The drilling fluid also functions to transport the drilled material to the surface for disposal.
[0022] According to one embodiment, the pilot section 18 may have a section with at least one fluid passage 26 provided for return flow of the drilling fluid. There also may be other fluid passages 26 provided in the reamer section 20 of the drillout bi-center drill bit 10 as well.
[0023] Referring specifically to FIGS. 2B and 2C, side view perspectives of the drillout bi-center drill bit 10 of the present invention are shown. One important characteristic of the drillout bi-center drill bit 10 is its ability to drill a borehole 11 into the earth 13 with a gauge drilling diameter larger than the inside diameter of the casing 15 , or pipe or other type of conductor the bit 10 passes through, which is shown in FIG. 2C.
[0024] Another important characteristic of the of the drillout bi-center drill bit 10 is its ability to drill out cement 19 (and related hardware, not shown) inside the casing 15 as shown in FIG. 2B without causing damage to the casing 15 or the cutting elements 24 of the drill bit 10 .
[0025] Turning now to FIG. 3, an end view of a drillout bi-center drill bit 10 of the present invention is shown. The gauge drilling diameter, as indicated by the circle 28 , is generated by radius R 1 from a first center of rotation 30 of the pilot section 18 . In this drilling mode, the circular portion of the pilot section 18 will be concentric with the diameter 28 . The cutting elements 24 on the portion of the reamer section 20 radially furthest from the first center of rotation 30 actually drills the gauge drilling diameter of the borehole 11 , as indicated at numeral 31 . The reamer section 20 is formed eccentrically of the pilot section 18 , so only a portion of the wall of the borehole 11 is in contact with the cutting elements 24 , which cut the final gauge of the borehole 11 at any given time during operation.
[0026] The drillout bi-center drill bit 10 also has a passthrough diameter, as indicated by the circle 32 , generated by radius R 2 from a second center of rotation 34 of the pilot section 18 . The shortest linear distance at the face of the bit between the centers of rotation 30 , 34 is indicated as non-zero distance D. The second center of rotation 34 is on the centerline of the smallest cylinder that may be fitted about the drillout bi-center drill bit 10 . To be effective, the passthrough diameter that is indicated by circle 32 must be smaller than the inside diameter of the casing 15 that the drillout bi-center drill bit 10 must pass through.
[0027] For optimal life, the cutting elements 24 must be oriented on the pilot section 18 in a known manner with respect to the direction of scraping through the material being drilled. This is no problem for bi-center drill bits that do not drill the cement 19 and related hardware out of the casing. However, when a drillout bi-center drill bit is drilling the cement 19 and related hardware in the casing, some of the cutting elements 24 may be subjected to reverse scraping while rotating about the second center of rotation 34 . Reverse scraping often causes rapid degradation of the cutting elements 24 .
[0028] The cutting elements 24 are typically polycrystalline diamond compact cutters or PDC. A PDC is typically comprised of a facing table of diamond or other superhard substance bonded to a less hard substrate material, typically formed of but not limited to, tungsten carbide. The PDC is then often attached by a method known as long substrate bonding to a post or cylinder for insertion into the bit body 12 . This PDC type of cutting element 24 is particularly sensitive to reverse scraping because loading from reverse scraping can easily destroy both the diamond table bonding and the long substrate bonding.
[0029] In prior art drill bits, the cutting elements are typically configured with a single cutting surface, where the cutting surface is properly oriented to cut through material being drilled when the drill bit rotates around a first center of rotation, such as center of rotation 30 , for example. However, when the drillout bi-center drill bit 10 rotates around a second center of rotation, such as center of rotation 34 , for example, the cutting surface of the cutting element is not properly oriented to optimally cut through the drilled material. That is, when the cutting element is configured with this single cutting surface, the drill bit is optimally utilized while drilling around the first center of rotation, but is not optimally positioned to cut material when the drill bit rotates around a second center of rotation. With this particular prior art configuration, the cutting element will undesirably wear at a faster rate when the drill bit is rotating around the center of rotation where the single cutting surface of the cutting element is not optimally positioned to cut material. As a result of the cutting elements wearing at a faster rate, the life of the drill bit is undesirably shortened.
[0030] As previously stated, the distance D is the shortest linear distance between center of rotation 30 and center of rotation 34 . As shown in FIG. 4A, a first region 56 of the pilot section 18 , centered about the first center of rotation 30 , has a radius D. A second region 58 of the pilot section 18 is centered about the second center of rotation 34 , and also has a radius D. A third region 60 of the pilot section 18 is formed by the intersection of the first region 56 and the second region 58 . This iris shaped third region 60 is the critical area where reverse cutter scraping is possible.
[0031] Turning now to FIG. 4B, a perspective view of cutting elements of the embodiment of the drillout bi-center drill bit of FIG. 8 is shown. Three cutting elements 72 , 74 , 76 (FIGS. 5 - 7 ) of the present invention are shown in the iris shaped third region 60 between the drilling center of rotation 30 and the passthrough center of rotation 34 .
[0032] Cutter 72 has two cutting faces 78 , 80 . When the drillout bi-center drill bit 10 is rotating about the drilling center of rotation 30 , cutting face 80 of cutter 72 is properly oriented for cutting along the path indicated by arrow 82 . Cutting face 80 is generally oriented perpendicular to the direction of travel of the cutter 72 in this operating mode, which is parallel to dashed line 86 passing through about the drilling center of rotation 30 .
[0033] In a similar manner, when the drillout bi-center drill bit 10 is rotating about the passthrough center of rotation 34 , cutting face 78 of cutter 72 is properly oriented for cutting along the path indicated by arrow 84 . Cutting face 78 is generally oriented perpendicular to the direction of travel of the cutter 72 in this operating mode, which is generally parallel to dashed line 88 passing through about the passthrough center of rotation 34 .
[0034] Cutter 72 may be formed of any material suitable for drilling earth formations. Since the wear rate of cutting elements near the center of the bit is generally low, cemented tungsten carbide may be a suitable material. It is understood that during drillout operation, only a small amount of wear is likely to occur on cutting face 78 of cutter 72 . It would be expected that much more wear would occur on face 80 when the bit is drilling into the earth. If the wear rates are unacceptably high, the cutter 72 may be formed of an infiltrated material comprising metallic powders such as tungsten carbide mixed with diamond particles and a binder.
[0035] Cutter 74 operates in a manner similar to cutter 72 , although as described later, cutter 74 is intended for much more abrasive drilling than cutter 72 . Cutter 74 has two cutting faces 90 , 92 . When the drillout bi-center drill bit 10 is rotating about the drilling center of rotation 30 , cutting face 90 of cutter 74 is properly oriented for cutting along the path indicated by arrow 94 . Cutting face 90 is generally oriented perpendicular to the direction of travel of the cutter 74 in this operating mode which is parallel to dashed line 98 passing through about the drilling center of rotation 30 .
[0036] In a similar manner, when the drillout bi-center drill bit 10 is rotating about the passthrough center of rotation 34 , cutting face 92 of cutter 74 is properly oriented for cutting along the path indicated by arrow 96 . Cutting face 92 is generally oriented perpendicular to the direction of travel of the cutter 74 in this operating mode which is parallel to dashed line 100 passing through about the passthrough center of rotation 34 .
[0037] In order to survive severe, abrasive drilling conditions the cutting face 90 of cutter 74 is quite different from that of cutter 72 . A PDC cutting element 102 is mounted on cutting face 90 a small distance 104 from the end 106 of cutter 74 exposed at the drilling face 17 of the drillout bi-center drill bit 10 . During the drillout phase, a small amount of wear will occur on end 106 . After drillout, the bit will then start drilling a full diameter hole in the earth. However, in abrasive drilling conditions, even cutters near the center will wear rapidly. Therefore, the end 106 of cutter 74 will wear rapidly, exposing the PDC element 102 . Once this happens, the cutter will wear at a rate comparable to other PDC cutters near the center.
[0038] In this embodiment, the PDC is attached to the cutter 74 by a method known as long substrate bonding. The cutter 74 is then inserted into the bit body 12 , which gives the PDCs an alternative orientation with respect to the center of rotation about which the drill bit 10 rotates.
[0039] It should be apparent that cutters 72 and 74 will generally have different orientations of cutting faces 78 , 80 , 90 , 92 depending where they are located within the iris shaped third region 60 between the drilling center of rotation 30 and the passthrough center of rotation 34 . Although some mismatch of cutting faces 78 , 80 , 90 , 92 would be tolerated, allowing some commonality of cutting face orientations, many different configurations of cutters 72 and 74 would still be necessary for most drillout bi-center drill bits 10 .
[0040] Another embodiment of the invention which can be placed anywhere in the iris shaped third region 60 , a cone shaped cutter 76 suitable for very non-abrasive drilling condition, is shown in FIG. 7. In cutter 76 , the side 108 is generally conic and may terminate in a flat top 110 that is also exposed at the drilling face 17 . Since these cutters 76 are generally symmetrical, they may be placed anywhere within the iris shaped third region 60 between the drilling center of rotation 30 and the passthrough center of rotation 34 . In this cutter 76 , the cutting edge 112 is the intersection of the side 108 and the flat top 110 . Since cutter 76 is generally symmetrical, both drillout and passthrough drilling are readily accomplished. Although not particularly “sharp”, cutter 76 is suitable for non-abrasive drilling conditions.
[0041] Shown in FIG. 8 is a particular bit configuration where the cutting functions for drillout and full diameter drilling are embodied in separate cutters. Two drilling face sections 17 are shown on bit body 12 . A plurality of conventional cutters 24 is shown with arrows 114 indicating their path of rotation about the drilling center of rotation 30 . A plurality of cutters 116 (shown in FIG. 9) have cutting faces 118 oriented for drilling out, with arrows 119 indicating their path of rotation about the passthrough center of rotation 34 .
[0042] The tops 120 of cutters 116 are orientated relatively farther from the bit body 12 than the remainder of cutters 24 on the drilling face section 17 of the drillout bi-center bit 10 . Therefore the cutting faces 118 of cutters 116 will engage the drillout material and prevent damage to cutters 24 during drillout. Once drillout is complete, the cutters 116 will rapidly wear, allowing the cutters 24 to drill normally. The operation is therefore effectively the same as cutter 74 . Cutter 116 may be formed of any material suitable for drilling earth formations. However, similar to cutter 74 , a cemented tungsten carbide material or an infiltrated material comprising metallic powders such as tungsten carbide mixed with diamond particles and a binder is suitable. In this embodiment and similar to cutters 72 , 74 and 76 the cutter 116 is oriented as necessary then fixed into the bit body 12 .
[0043] An alternate embodiment for the arrangement of the drillout cutters shown in FIG. 8 is possible when the bit body 12 is an infiltrated powdered metal matrix material. When this is the case, the cutter 122 is formed as a bump in the matrix of the bit body 12 . The cutting face 118 , and top 120 , of cutter 122 function identically to cutter 116 . However, because matrix bits are made in a molding process, orienting and fixing the cutters 122 into the bit body 12 is not necessary. Cutter 122 is integral with the bit body. Methods of construction of matrix drill bits are well known in the art. Accordingly, the specific details of such will not be disclosed herein to avoid unnecessarily obscuring the present invention.
[0044] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below.
[0045] Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.
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A drillout bi-center bit includes first and second axes of rotation separated by a distance D, a first region of radius D centered on one of the axes of rotation, a second region of radius D centered on the other of the axes of rotation, and a third region defined by the overlap between the first and second regions, wherein the cutters provided within the third region are designed to withstand cutting in opposing cutting directions. This may be achieved by providing each cutter with two cutting faces, or by providing two groups of cutters, one group arranged to cut in one direction, the other group being designed to cut upon rotation in the other direction, one of the groups protruding from the bit body of the bit to a greater depth than the other group.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPEMENT
[0002] Not Applicable.
REFERENCE TO SEQUENCE LISTING
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] Math applications continue to exist in our everyday lives and it has become necessary for people to grasp a basic understanding of the topic. However there are individuals that struggle with math applications, not only in the real world but also academically. This invention, Ten0, enables people not only to understand how to apply math when needed but it also builds confidence in the process. Additionally this invention also allows young students to excel in the subject.
BRIEF SUMMARY OF THE INVENTION
[0005] This invention Ten0, signifies the importance of Math and reminds us of why we need it to be integrated in our daily lives. Ten0 has several qualities, which comprise of fun, competitive learning and entertainment. The game also consists of different levels that involves interactive skills and allows every individual to have fun at every level. Ten0 prepares people for real-world applications. More importantly, we are able to learn how the math operations are applied by learning the sequence of operands. Playing the game is extremely fun for the family, friends and even among strangers while being a mentally stimulating challenge. Ten0 can be played by all ages, specifically 8 and above.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0006] FIG. 1 : The front face of the card.
[0007] FIG. 2 : The back face of the card.
[0008] FIG. 3 : Switch0 card.
[0009] FIG. 4 : Zero0 card.
[0010] FIG. 5 : Ten0 card.
[0011] FIG. 6 : Ten0 Scale Reading card; instructs players what operand to use within the cumulative point domain.
[0012] FIG. 7 : The back face of the card specifically with a divide operand.
[0013] FIG. 8 : The back face of the card specifically with a add operand.
[0014] FIG. 9 : The back face of the card specifically with a subtract operand. All figures are detailed below in the section labeled “Detailed Description of the Invention”.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Objective of Ten0:
[0016] The math must be applied with respect to the card and to the player's best ability. The cumulative score must be an absolute value and there should be no decimals or negative numbers and should not be outside of the Ten0 Scale Reading. Further details about Ten0 Scale Reading are in the following pages. The following is an example of how the game is played with an absolute cumulative point value. If one player throws a card labeled “5” and its sign is “+” and another player throws a card labeled “3” and it′ sign is “+”, then the math applied would be 5+3=8. The current cumulative point total is 8 and the next player goes. A player must finish the hand in order to win the game.
[0017] Tool:
[0018] A Deck of Cards
[0019] Players Participate in the game:
[0020] 2-6
[0021] Cards:
[0022] Number of cards in a deck:
[0023] 100
[0024] Symbols Desiqned in the cards:
[0025] “+” (Add); “−” (Subtract); “×” (Multiply); “/” (Divide).
[0026] Face Card Value:
[0027] 1- 10 (2 times for each operand)-80 cards
[0028] Number of Special Cards:
[0029] 12 cards
[0030] Name of Special Cards:
[0031] “Switch0” Card-4 cards; “Ten0” Card-4 cards; “Zer0” Card-4 cards. All features are in “Drawings” section.
[0032] Ten0 Scale Reading:
[0033] It has an absolute domain of 0 to 100 and the operands displays-4 cards. It is enclosed in the “Drawings” section. The remaining 4 cards are instructions, miscellaneous or displays.
[0034] Definitions of Special Cards:
[0035] “Switch0” Card: can turn the Addition sign “+” to a Subtraction sign “−” and vice versa. It can also turn the Multiplication sign “×” to a Division sign “/” and vice versa.
[0036] “Ten0” Card:
[0037] This card is considered a bonus or wild card. A player can use this card by choosing any operand in the game regardless of the operand stated on a specific card. Specific operands are adding, subtracting, multiplying, and dividing. The “Ten0” card can be used regardless of where the current cumulative point is. For an example: If the first player throws a card labeled “5” and it's sign is “+”, and the second player throws a card labeled “3”and it's sign is “+”, then the math applied would be 5+3=8. The current cumulative point total is 8. Now it is the first player's turn and he chooses to use a “Ten0” card. The player uses a “Ten0” card with another card in his or her hand such as “4 +” but doesn't want to use the add operand. Fortunately with the “Ten0” card, the player can change the operand however the player chooses. The player changes the “4+”, to “4 ×” which translates to 4×8. The current cumulative point is at 32 and the game continues. Also, a player can use the “Ten0” card and change the second card to a division operand card only if the remainder of the function is strictly 1. A further detail is below in the Situations in “Ten0 Game”; specifically situation # 7.
[0038] “Zer0” Card:
[0039] This card is considered another bonus card. A player can choose whichever operands (adding, subtracting, multiplying, or dividing) to comply with the number 0 (zero). All features of the special cards are in the “Drawings” section.
[0040] Ten0 Game:
[0041] Objective:
[0042] Math must be applied appropriately and the cumulative point must be an absolute value between 0-100. The 50th point is considered as a neutral point where the next player can decide to use any operand to either go above 50 points or less.
[0043] 0-100 points:
[0044] The player must use, if the cumulative point is at:
[0045] 0-49: add or multiply.
[0046] 50: Players chooses which operand to play.
[0047] 51-100: subtract or divide. The math must be played appropriately and must be within the scale reading. The Ten0 Scale Reading is included in the “Drawings” section, FIG. 5 .
[0048] Instruction of “Ten0” Game:
[0049] There can be 2 to 6 players that can participate in this game and there are 92 cards that are used (80 operand cards and 12 special cards). Each player is dealt 5 cards. The player on the left of the dealer must start first. The starting cumulative point is 0. The first player must add if the player has the “add” card. The game optionally can have a pad to write down the cumulative points. Additionally, there is a Ten0 Scale Reading card to emphasize the utility of the cards played which is FIG. 5 on the “Drawings”.
[0050] Situations of “Ten0” Game:
[0051] 1. At the beginning of the game, the cumulative point is at 0. The first player must play an add operand to start. If the first player does not have the add operand card to start or special card(s), then a player must draw one card. If the first drawn card is playable then play the card. Otherwise, the first player must take another card and loses a turn regardless if the second drawn card is playable or not.
[0052] 2. If a player does not have a card that is playable then the player must draw one card. If the card that is picked is playable then the player can play, otherwise draw another card and lose a turn.
[0053] 3. If a player miscalculates the card during the game, then the player takes the card back and draws another card. Additionally the player loses a turn. For an example, a player draws a “5”, and it's operand sign is add and the current cumulative point is at 3. This specific player says 3+5=10, which is considered incorrect. The player takes the card back that was drawn which is the “5+” card, draws another card from the deck and loses a turn.
[0054] 4. If a player goes beyond the cumulative point, less than 0 or more than 100, then the player takes the drawn card back, draws another card, and loses a turn. The only exception is the “Ten0” card which can surpass the cumulative point, either 0 or 100. Although the cumulative point can surpass 0 or 100 mathematically, the points must be stated as the maximum of 100 or the minimum of 0.
[0055] For an Example:
[0056] Assuming the cumulative point is at 20, if a player throws a “Ten0” Card and chooses to use 10× card. The combination of the “Ten0 ” card will result over 100 (20×10=200) mathematically. However, the current cumulative point will be at 100 specifically. Vice versa for going below the cumulative point at 0.
[0057] The following is another scenario using “Ten0”card. The cumulative point is at 78 and a player chooses to use a “7/” card. Mathematically, it would be incorrect but with the “Ten0” card you can use it since the result will be 78/7=11 remainder 1. Therefore, the cumulative point is at 11 disregarding the remainder.
[0058] 5. If a player uses a card that results in a cumulative point of exactly 0, the next player must use the “add” operand.
[0059] 6. If a player has a “Zer0” card, then a player can choose to use whichever operand to comply with zero. For an example, the current cumulative point is at 55, and a player decides to use “Zer0” Card using a division operand, the result cumulative point is 0; since 55/0=0.
[0060] Ten0 Game (Advanced Level 1):
[0061] It is strictly for 2-4 players. Note if there are 3 players playing use the last card to start the game. There are 40 operand cards each for the add and subtract operands. There are also 40 operand cards for the multiply and divide operand. There are two different games that can be played with the cards. The first game consists of cards that only have the add and subtract operands, and the second is for multiply and division operands. A further explanation is detailed below.
[0062] Objective for Add and Subtract Operands:
[0063] For add and subtract operands, the players can use combinations of both add and subtract cards. Add and subtract operands cards are separated from the deck. All the special cards are excluded from the game. The players must compete with each other until a player's hand is finished.
[0064] Instruction:
[0065] The players have an equal amount of cards dealt to them. The cumulative point starts out at 0. The first player must add first to start the game. For an example, starting the cumulative point at 0, the first player starts to use add operand with 7 on the face value. At this point, the cumulative point is at 7, then the second player throws down subtract operand with the face value 5 and says 2. They go ahead and compete; using strictly add and subtract operands to play this game.
[0066] Situation:
[0067] 1. If a player miscalculates when playing a card, the player then takes the card back.
[0068] 2. If a player does not have a card that is playable, then the player must hand pick one card from any other player without looking and then loses a turn. It must be hand picked from a player who has more than one card. If all the other players have one card left on their hand then the player keeps his own card and loses a turn.
[0069] 3. If no players can play on a specific round or cannot finish one last card, then shuffle the cards that have been played and set it up as a deck.
[0070] Once it is a player's turn, the player must pick a card from a deck and play it, if playable. Otherwise, draw another card and lose a turn.
[0071] 4. For a game with 3 players the cards are dealt equally and the remaining one card is used to start the game. If the last card is not an add operand then the first player must put an add operand card to start the game; the add operand card will be on top of the last dealt card.
[0072] Objective for Multiply and Division Operands:
[0073] For multiply and division operands, the multiply and division operands cards are separated from the deck. All the special cards are excluded from the game. The first two players must use a multiply card to initiate the game. A player throws the first multiply operand card and the next player must also throw a multiply operand card to start a cumulative point. The players continue the game using only the division and multiply operands. In addition to this, the players must not surpass the absolute cumulative point between 0 and 100. The only exception of this objective is that the cumulative point does not start at 0.
[0074] Instruction:
[0075] The players are dealt an equal amount of cards. The cumulative points are formed using the combinations of the division and multiplication operands.
[0076] For an example, the first player starts using the multiply operand with the face value 7 and the second player throws down a multiply operand card with the face value 5 and says 35. Currently the cumulative point is at 35. The next player decides to throw a 5 with the division operand. The cumulative point is back at 7 and they go ahead and compete.
[0077] Situation:
[0078] 1. If a multiplication or division miscalculation occurs, then the player takes the card back that was already played and also loses a turn.
[0079] 2. If a player does not have a card to play with, then the player must take one card from any other player who has more than one card on hand; hand picked without looking and loses a turn.
[0080] 3. If all players cannot play on a specific round, then shuffle the cards that have been played and set it up as a deck. Once it is a player's turn, the player must pick a card from a deck and play it, if playable. Otherwise, draw another card and lose a turn.
[0081] Ten Game (Advanced Level 2):
[0082] Objective:
[0083] Math must be played appropriately with its respect. The rules that are applied in respect to the cumulative point and the instructions are the same as above.
[0084] Ten0 Game
[0085] This game is for 2 to 6 players. There are no special cards included in this game; therefore there are only 80 operand cards to play with. This advanced game also has the same rules, however exceptional situations are detailed below. The major difference is that instead of focusing on the operands applied the players can manipulate any operand within the “Ten0 ” Scale Reading cumulative point. In other words, you can use any operand that is appropriate to apply and must be within the absolute domain value of 0 to 100.
[0086] Instruction:
[0087] Each player is dealt an equal amount of cards until the deck is finished. If there is a remainder of cards they are used to start the game. There are a couple of alternatives to start the game with the remainder cards.
[0088] First Alternative:
[0089] Take the card with the add operand to start the game if available. If not available, use the second alternative.
[0090] Second Alternative:
[0091] Take the card with the highest face value to start the game regardless of the operand. The resulting cumulative point is the highest face value, which is the card chosen. For an example: The remainder cards are “5/”, and “7×”. The game begins by choosing the 7 and this is the starting cumulative point.
[0092] Situation:
[0093] 1. If any math miscalculation occurs, then the player takes the card back that was already played and loses a turn.
[0094] 2. If a player does not have a card to play with, then the player must take one card from the any other player; hand picked without looking and loses a turn. The player must pick a card from another player who has more than one card.
[0095] 3. If no players can play on a specific round, then shuffle the cards that have been played and set it up as a deck. On the next player's turn, the player must pick a card from the deck and play it, if playable. Otherwise, draw another card and lose a turn.
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Ten0 is an entertaining, multi-level card game involving the findamentals of math. It is inclusive of four operands that are central to the game. The Ten0 also features a Ten0 scale reading and special cards. One of the unique features of this game is that it is an educational game and also a fun game. The various math applications provide the basic building blocks needed throughout life. It also helps build confidence for those that are not entirely comfortable with math applications. Additionally, the multi level feature enables the game to be stimulating for people of all ages.
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BACKGROUND OF THE INVENTION
A freely rotatable spinning ring having air-bearings for generally friction-free support thereof may be rotated by the frictional drag of a yarn traveler mounted on the ring as yarn is simultaneously twisted or spun and wound onto a yarn carrier or bobbin rotating inside the ring. The traveler rotates about the axis of the yarn carrier at a rotational speed only slightly less than that of the yarn carrier, the difference in speeds allowing the yarn fed to the yarn carrier to be wound thereon under generally uniform tension while compensating for differences in the winding-on diameter of the yarn package being built on the yarn carrier.
In conventional stationary spinning ring apparatus a practical limit on production speeds, or critical speed, is reached when the linear speed of the traveler orbiting the stationary ring is in the neighborhood of 5000 feet per minute. Above that speed, the friction of the traveler on the ring becomes so great that frictional heat tends to burn up the traveler, and the friction becomes erratic as well, tending to overstress and break the yarn.
By allowing the ring to rotate freely on very low friction bearings, the frictional force between traveler and ring causes the ring to rotate at a speed generally approximating that of the traveler, so that while the traveler will have some sliding motion on the ring (thereby compensating for short-term variations in winding-on speeds), the average linear sliding speed will be very low, thereby practically eliminating wear between ring and traveler and causing the frictional forces therebetween to be much more even with a resultant reduction in yarn breaks. Also, the yarn carrier can be rotated at much higher speeds, generally limited only by the mechanical capabilities of the bearings and drive for the rotating spindles on which the yarn carrier is mounted.
The advantages of freely rotating spinning rings are well known to those skilled in the art, as are the problems associated therewith, the principal problems being those of (a) achieving a balanced air flow to and within the radial and annularly axial (or cylindrical) air-bearings provided for each ring, and (b) preventing yarn tangling and breaking when the spindle drive is cut-off and spindle and ring are coasting to a stop at undesirable relative deceleration rates.
Prior art air-bearings for spinning rings have included multiple small holes disposed in the bearing walls for distributing air thereto from surrounding air chambers, and in some cases the small holes have been the porosity in sintered metal porous annular elements forming portions of the air-bearing structure. Such small holes tend to become stopped-up periodically or accidentally and may have peculiar non-uniform air distribution tendencies even when open, and these tendencies may be compounded when both cylindrical and radial air-bearings are supplied together by small holes in the cylindrical bearing walls. Where only a few small holes equally spaced around an air bearing are used to admit air (4, 8, and 16 holes are typical of the prior art patents mentioned hereinafter), it is probable that the full area of the air bearing surfaces is not being used efficiently, and that higher air pressure must be used to center and support the rotating ring member by means of the concentrated areas around the small holes where the air pressure is concentrated than if the full air-bearing surfaces were being used efficiently. Also, tiny particles of dirt or trash which inevitably turn up in compressed air systems may enter through the small air inlet holes and be dragged annularly around the air-bearing to jam in the solid bearing surfaces between the holes.
Air-bearing spinning rings in the prior art have had such low friction and high inertial forces that, once rotating, they tend to coast for extended periods of time, generally for longer periods of time than the spindles and yarn carriers of the spinning apparatus, after driving power is cut off. Therefore, the traveler on the rotating ring may rotate faster than the carrier toward the close of such periods of time, causing loss of yarn tension control as the yarn unwinds from the carrier and tangles and breaks.
In some cases, the air supply to the air-bearings of the rotating ring has been cut-off simultaneously with the power drive for the spindles and carriers, and then the ring has tended to decelerate so quickly that the aforementioned 5000 foot per minute critical speed of the traveler relative to the ring is reached before the carrier rotational speed has decelerated sufficiently to preclude such a condition.
U.S. Pat. Nos. 3,324,643, 3,481,131, and 4,023,342 disclose in detail the principles and prior art practices of yarn spinning or twisting with traveler-equipped freely rotating air-bearing spinning rings discussed above; however it is believed that there is no such equipment commercially available in the United States at this time. U.S. Pat. Nos. 950,507, 3,494,120, 3,611,697, 3,664,112, 3,851,448, 4,028,873, 4,030,282, 4,051,657, and 4,095,402 also disclose material useful in understanding the prior art.
On the basis of experiments with a working model, it appears that the present invention provides effective means for providing uniform air distribution within the radial and cylindrical air-bearings, for providing suitably balanced air distribution between the radial and cylindrical bearings, and for causing the rotating ring to decelerate in desired relation to the spindle, carrier, and traveler (upon cutting-off their driving power) to maintain suitable tension in the yarn throughout the deceleration. The means provided by the present invention for overcoming the technical problems and allowing trouble-free operation are so simple and effective that they should permit a practical initial cost and low maintenance costs during production spinning or twisting, thereby assuring commercial success through application of the apparatus to a large number of existing spinning and twisting spindles in the United States. It is believed that production increases in the order of 50% to 100% may be achieved at a cost of 30%, or less, of the cost of new equipment, and a reduction in mill space and operating personnel will also be realized as compared with adding machinery of conventional construction to achieve corresponding production increases.
SUMMARY OF THE INVENTION
The air-bearing supported spinning or twisting ring apparatus of the present invention includes a ring holder formed with an axially extending circular wall portion and a generally radially extending wall portion, and a ring member freely rotatably mounted within the ring holder and having a circular wall portion and a radial wall portion disposed in closely spaced relation to the circular wall and the radial wall, respectively, of the ring holder to form communicating narrow axial and radial spacings therebetween to receive air for rotatably supporting the ring member in the ring holder, thereby forming the air-bearing supported apparatus. At least one of the circular wall portions has an annular plenum cavity disposed in generally open, unencumbered, and substantially continuous communication with the narrow axial spacing. The apparatus includes means for admitting pressurized air to the plenum cavity, and also includes a yarn traveler mounted on the ring member for sliding movement therearound. The apparatus includes a rotatable yarn carrier for receiving yarn thereon, power means for rotating the yarn carrier, and means for selectively de-energizing the power means, engagement of the yarn traveler by the yarn causing sliding rotation of the traveler about the ring member. The means for admitting air to the plenum cavity for supplying air to the air-bearing includes selectively operable means for reducing the flow of air thereto for rotatably supporting the ring member, and control means interconnects the de-energizing means and the air flow reducing means for operation of the air flow reducing means after the de-energizing of the power means. The control means includes selectively adjustable timer means for delaying the operation of the air flow reducing means for a predetermined time after the de-energizing means has been operated to cause the rotating ring member and the rotating yarn carrier to decelerate in predetermined relation to one another whereby suitable tension is maintained in the yarn by the traveler throughout the deceleration.
Preferably the embodiment of the present invention includes an annular mouth portion of the annular plenum cavity which is enlarged by at least one generally radially disposed annular wall portion thereof which is flared outwardly toward the axial spacing between the ring holder and the ring member. The axial and radial annular spacings between the ring holder and the ring member communicate with each other through at least one generally annularly disposed mutually connecting enlargement of the spacings, and the apparatus includes a ring rail for support of the ring holder. The ring rail has an opening therethrough for reception of the ring holder therein, and the ring holder has a generally cylindrical lower portion thereof which has a chamfer on the lower outer edge thereof for facilitating the reception of the holder into the opening and providing a suitable location for the means for admitting pressurized air to the annular plenum cavity. The means for reducing the flow of air to the air-bearing preferably includes cut-off means for stopping the flow of air to the air-bearing means, and alternatively may include means for reducing the flow of air to a point at which the ring member is rotatably supported by the flow of air only at the circular portion of the air-bearing means and not at the radially extending portion thereof.
In the preferred embodiment of the present invention the outwardly flared generally radially disposed annular wall portion of the annular plenum cavity is flared outwardly at an angle of about 15°, and the circular wall portions of the ring holder and the ring member extend in slight angular relation to one another to cause the narrow axial spacing therebetween to increase gradually in axial direction toward the radial spacing between the ring holder and the ring member.
The method of controlling yarn tension during stop-off of a rotating spinning or twisting ring apparatus for twisting textile fibers and winding them as yarn onto a rotating yarn carrier according to the present invention is based upon the spinning ring being freely rotatably supported by an air-bearing supplied with air under pressure, and upon the apparatus including power means for rotating the yarn carrier at a high operational speed while a traveler slidably mounted on the rotating spinning ring engages the yarn and causes the yarn winding onto the carrier to be under suitable tension at the high speed. The method includes the steps of: cutting off the power means to initiate the stop-off while maintaining air pressure in the air-bearing; continuing to maintain the air pressure while allowing the rotating yarn carrier and the rotating spinning ring to decelerate from the high operational speed after the cutting-off for a predetermined time period; and reducing the air pressure in the air-bearing at the end of the time period whereby the rotating spinning ring is caused to decelerate more rapidly relative to the yarn carrier than during the time period and to stop prior to the yarn carrier.
In the preferred method of controlling yarn tension as described above, the aforesaid reducing of the air pressure in the air-bearing includes a reduction to atmospheric air pressure (by cutting off the air being supplied under pressure to the air-bearing), or, alternatively, includes a reduction to another air pressure at which the spinning ring is freely rotatably supported only by the circular portion of the air-bearing and not by the radially extending portion thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional view of a ring spinning frame according to the present invention taken endwise of the ring rail at a typical spinning position and including a schematic illustration of the electrical controls, air supply, power driving means, and timer for the air supply;
FIG. 2 is an enlarged partial cross-sectional view of a portion of FIG. 1 indicated by the broken-line circle 2--2 thereof; and
FIG. 3 is a broken-out portion of the air supply schematic of FIG. 1 showing an alternative embodiment including an additional regulator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The air-bearing supported rotating spinning ring and traveler apparatus of the present invention is suitable for substitution in a conventional stationary ring and traveler spinning frame or machine such as is well known in the textile machinery and manufacturing arts. Therefore, the only parts of the conventional spinning frame shown in the drawings in detail are the conventional ring rail (which typically extends the length of one side of the spinning frame and may have one hundred and fifty or more ring spinning positions disposed therealong), and the conventional spindle (which extends vertically through an opening in the ring rail at each spinning position and is driven at a rotational speed of thousands of revolutions per minute). Conventional electrical controls and power means for the frame are shown schematically, as are a timer and other conventional devices arranged for supply and control of pressurized air to the air-bearings of the invention in a novel manner, and their use with the novel elements of the rotating ring and traveler is described in detail hereinafter.
A ring holder 10 is provided with a cylindrical body 12 and an outwardly extending flange 14 at the upper portion thereof. The lower portion of the body 12 has a chamfer 16 to facilitate insertion thereof into a conventional opening 18 in a conventional ring rail 20 of a textile spinning frame (not shown). The flange 14 of the ring holder 10 rests on the ring rail 20 and is releasably secured in position there by an O-ring 22 fitted into a groove 24 in the body 12 of the holder 10. The ring holder 10 has a generally cylindrical bore or circular wall portion 26 extending generally axially thereof for reception therein of the generally cylindrical body 28 of a rotating ring member 30.
The ring member 30 has a support flange 32 extending radially outwardly therefrom at the upper portion of the body 28 for support by a radially extending wall portion 34 forming the top surface of the ring holder 10. A counterbore 36 is provided at the inner upper portion of the body 28 of the rotating ring member 30 for reception of a conventional spinning ring 38 thereinto in press fit relation whereby the ring 38 is made an essentially permanent part of the ring member 30, forming the topmost portion thereof and providing a flange 40 for sliding engagement by a conventional ring traveler 42. A cylindrical clearance bore 44 extends through the body 28 of the rotating ring member 30 concentrically therewith allowing space for building a conventional yarn package P on a conventional yarn carrier or bobbin C which is mounted concentrically within the ring member 30 on a conventional rotating spindle 45 of the aforementioned textile spinning frame.
The underside of the flange 32 forms a radially extending wall portion 46 of the ring member 30 which, in operation, is disposed in closely spaced relation to the radially extending wall portion 34 of the ring holder 10 as illustrated in exaggerated fashion in FIG. 2 by the narrow radial spacing 48 shown therebetween as will be explained hereinafter. The circular wall portion 50 forming the outer surface of the cylindrical body 28 is similarly disposed in closely spaced relation to the generally axially extending circular wall portion or bore 26 of the ring holder 10 as illustrated in exaggerated fashion in FIG. 2 by the narrow axial spacing 52 disposed annularly therebetween as will be explained hereinafter. The closely spaced radial and axial wall portions 46, 34 and 50, 26, respectively, together with their respective narrow spacings 48 and 52, form the aforesaid air-bearing when pressurized air is admitted thereto as explained hereinafter.
The circular wall portion 50 of the ring member 30 is tapered slightly outwardly in a direction toward the flange 32 thereof, on the order of 0.0004 inch of diameter per inch of length. The circular wall portion or bore 26 of ring holder 10 should be of untapered cylindrical form, so that the narrow axial spacing 52 increases gradually at the rate of about 0.0002 inch per inch of length toward the narrow radial spacing 48. An annular plenum cavity 54 is disposed intermediately of the length of the bore 26 and has a depth of about 0.030 inch and a width of about 0.125 inch. The narrow axial spacing 52 is about 0.001 inch in the vicinity of the cavity 54, a very small spacing in comparison with the cross-sectional area of the cavity 54. The cavity 54 is formed with generally radially disposed annular wall portions 56 which are each flared outwardly toward the axial spacing 52 at an angle of about 15° (as seen in exaggerated form in FIG. 2).
The bore 26 is chamfered slightly at its lower end for neatness, but a chamfer 58 of about 0.062 inch by 45° is provided at its upper end to form an annularly disposed mutually connecting enlargement 60 of the narrow radial and axial spaces 48 and 52 by which the spaces communicate with each other.
The chamfer 16 at the lower outer edge of the ring holder 10 provides a suitable location for an angularly disposed hole 62 extending therefrom into the annular plenum cavity 54. The hole 62 is threaded at its outer end for reception of a threaded hose fitting 64 preferably having a barbed nipple 66 on one end thereof for reception and retention thereover of a length of plastic tube or hose 68. The angular disposition of the hole 62 is convenient in that it allows the hose 68 to be connected to the ring holder 10 to extend laterally of the ring rail 20 without interference therewith; and it also presents the possibility of using a much larger plastic tube or hose (not shown) having radially disposed holes spaced along one side thereof (at the same spacing as the aforesaid ring spinning positions along the ring rail 20) for reception of a barbed nipple 66 from each ring holder 10 along the ring rail 20, the large tube thereby forming a plenum chamber as well as a means of transmission for supplying pressurized air uniformly to the plenum cavities 54 at each ring spinning position.
A compressed air source 70, which may be the typical textile mill compressed air system, is connected to the tube 68 through suitable conduits (shown schematically in FIG. 1) and through a suitable conventional air pressure regulator 72, solenoid operated on-off valve 74, and air filter 76 (shown schematically in FIG. 1) which form means to selectively supply and cut-off pressurized air to the plenum cavity 54. Conventional machine or spinning frame controls 78 include means for selectively energizing and de-energizing a conventional power means 80 (typically electric-motor-driven) for rotating the spindle 45 and the yarn carrier C thereon. Further controls include a selectively adjustable timer means or time-delay relay 82, such as is well known and may be of electronic or electromechanical or other construction. The timer 82 is electrically interconnected with the controls 78, the power means 80, and the solenoid valve 74 such that upon energization of the power means 80, the solenoid valve 74 is immediately opened to supply pressurized air to the plenum cavity 54; and upon de-energization of the power means 80, a selectively predetermined time period for delaying the operation of the valve 74 is initiated after which the valve 74 is closed to stop the flow of air to the plenum 54. Additional filters or moisture separators or other air treating or control means may be necessary between the air source 70 and the balance of the air circuit, depending upon local conditions.
In operation, upon energization of the power means 80, the spindle 45 will start to rotate, accelerating within seconds to its operational speed of thousands of revolutions per minute, the yarn carrier or bobbin C rotating with it. A strand of textile yarn Y extends from the yarn package P being built on the bobbin C to conventional engagement with the ring traveler 42 and thereabove through a pigtail yarn guide (not shown) as is well known in the art. Rotating the bobbin C causes the yarn Y to pull the traveler 42 around the flange 40 of the spinning ring 38, and sliding friction therebetween tends to rotate the ring 38 and thereby the rotating ring member 30. Energization of the power means 80 having caused the solenoid valve 74 to open and admit pressurized air to the plenum cavity 54 and thereby to the narrow spacings 48 and 52, the rotating ring member 30 is supported by the air for free rotation within the ring holder 10. Thereafter, the relatively low frictional force exerted by the traveler 42 on the ring 38 will gradually accelerate the ring member 30 to an operational rotational speed approaching that of the bobbin C, and the traveler 42 will slide around the spinning ring 38 with decreasing relative velocity during that acceleration. During constant speed rotation of the bobbin C after the initial accelerations of the bobbin C and the ring member 30, the rotational speed of the traveler 42 changes according to the diameter of the yarn package P at the location where the yarn Y is being wound on, as is well-known in the art, the traveler on average lagging behind the bobbin just enough to cause the yarn being fed through the pigtail to the bobbin to be wound onto the bobbin at a suitable tension as determined by the particular conditions of yarn weight, yarn strength, yarn package diameter, rotational speed, traveler weight, etc. that have been selected. Any rapid changes of the traveler rotational speed will be accommodated by more or less sliding of the traveler 42 on the rotating spinning ring 38, the rotating ring member 30 having sufficient rotational inertia so that its rotational speed will be changed only relatively slowly in response to changes in the frictional forces exerted by the traveler 42 on the ring 38 due to changes in the traveler rotational speed. In any case, the sliding between the traveler 42 and the ring 38 due to the aforementioned rapid changes in traveler rotational speed should occur at velocities far below the aforementioned critical or limiting sliding speed (e.g. 5000 feet per minute) which is well known in the art and which causes undue yarn breaks and traveler wear, and travelers are expected to last until they are damaged by the yarn cutting into them.
At the moment when the power means 80 is de-energized to stop off the spinning frame, the spindle 45 and bobbin C immediately start to decelerate, as does the traveler 42. It is believed that wind resistance slows the traveler 42 and the ring member 30 generally proportionally to the slowing of the spindle 45 and bobbin C for a period after the power means 80 is de-energized, thereby maintaining suitable tension in the strand of yarn Y. However, if the pressurized air supply to the plenum cavity 54 is maintained constant indefinitely thereafter, a time will be reached when the ring member 30 and the traveler 42 thereon will rotate at a speed too nearly equal to or greater than that of the decelerating bobbin C (due to the extremely low friction characteristics of the air-bearing formed between the rotating ring member 30 and the ring holder 10 and the considerable rotational inertia of the ring member 30) and such relative speeds will cause loss of control over the tension in the yarn strand Y, even to the extent of unwinding the yarn Y from the yarn package P, thereby resulting in tangled or broken yarn.
Therefore, it is important that at some time after the power means 80 is de-energized, but before the aforementioned loss of tension control, the supply of pressurized air to the plenum cavity 54 should be cut-off, so that the rotating ring member 30 will no longer be supported by pressurized air between the radially extending wall portions 34 and 46 and the circular wall portions 26 and 50, and only atmospheric pressure will exist therebetween. The radially extending wall portions 34 and 46 will then come into ordinary sliding frictional contact, resulting in a considerably increased deceleration of the rotating ring member 30 in predetermined relation to the deceleration of the bobbin C, thereby causing the ring member 30 to stop prior to the stopping of the bobbin C, and thereby causing the ring member 30 and the bobbin C to decelerate in predetermined relation to one another from the moment of de-energizing the power means 80 whereby suitable tension is maintained in the yarn Y throughout the deceleration. The time delay period for cutting-off the air supply must be empirically chosen to insure that the air is cut-off before the rotational speed of the bobbin C drops too near to the rotational speed of the rotating ring member 30, and also to insure that the air cut-off occurs after the speed of the bobbin C has dropped below a point where the increased deceleration of the ring member 30 caused thereby could result in the traveler 42 sliding on the spinning ring 38 at a velocity exceeding the aforementioned critical or limiting sliding speed, such as 5000 feet per minute. It is to be understood that the actual critical speed, operational speed, traveler weight and shape, time delay period, and other yarn, bobbin, yarn package, airbearing, spinning frame, and environmental considerations are all so complexly related that the specific dimensions, speeds, and other conditions described herein may apply only to the disclosed embodiment, yet the principle of providing means for cutting off the pressurized air at a selectively predetermined suitable time after de-energization of the power means is important to the satisfactory commercial use of air-bearing supported rotating spinning rings with yarn travelers.
Operationally, provision of the comparatively large annular plenum cavity 54 permits equalization of air pressure all around the cylindrical air-bearing in the narrow axial spacing 52, and the connecting enlargement 60 between the axial spacing 52 and the narrow radial spacing 48 provides in essence another plenum cavity assuring equalization of air pressure all around the radial air-bearing in the narrow radial spacing 48. The enlargement 60 has a comparatively large cross-sectional area in comparison with the spacings 48 and 52 which it connects.
Also, the enlargement 60 seems to prevent the collection of oily moisture at the junction of the spacings 48 and 52 and in the spacing 48 and the consequent drag and slowing down of the free rotation of the ring member 30. Without the enlargement 60, the oily moisture which is typical in textile mill compressed air supplies appeared to collect in the sharp corner between the radially extending wall portion 46 and the circular wall portion 50 and to spread unevenly into the radial spacing 48, causing or allowing air to escape unevenly through the spacing 48 without carrying away the oily moisture. Adding the enlargement 60 cured the problem and allowed the air-bearing to function normally even when the moisture separation equipment of the mill air supply was defective and inoperative.
While the cavity 54 and the enlargement 60 have been disclosed herein as continuous annular air spaces, and these are preferred for ease of manufacture, they might alternatively be formed of discontinuous annularly disposed segments so long as they extend generally evenly and around the circular wall portions 26 and 50 and each is disposed in generally open, unencumbered, and substantially continuous communication with its adjacent narrow spacing or spacings to effectively achieve the aforesaid equalization of air pressure all around the narrow-spacings without the aforementioned disadvantages of a number of small holes for air distribution. Also, the cavity 54 and enlargement 60 might alternatively be included in the rotating ring member 30 rather than in the ring holder 10 as illustrated, and in that case the angularly disposed hole 62 should extend through the circular wall portion 26 of the ring holder 10 directly opposite the alternative cavity in the ring member 30.
The outwardly flared annular wall portions 56 of the cavity 54 appear to assure smooth, uniform air flow from the cavity 54 into the axial spacing 52. The gradual increase of the axial spacing 52 toward the radial spacing 48 aids in balancing air flow from the upper and lower ends of the axial spacing 52 and into the radial spacing 48 and appears to achieve a suitable balance advantageously in comparison with shifting the disposition of the cavity 54 axially along the bore 26. The sizes, shapes, and dispositions of all the above-mentioned elements might be varied in alternative embodiments of the invention without departing therefrom.
The preferred embodiment described in detail herein has performed satisfactorily at selected regulated air pressures varying between about 2 and 20 pounds per square inch, the lower pressures being preferable with due regard to compressed air consumption, and the radial spacing 48 being variable according to the pressure applied. An alternative embodiment, as illustrated in FIG. 3, might include an additional pressure regulator means 84 bypassing the solenoid valve 74, whereby the air flow and pressure supplied to the plenum cavity could be reduced to some predetermined lower flow and pressure at the end of the aforementioned time delay period when the air pressure from the regulator 72 is cut-off, such lower pressure to be selectively predetermined and set on the regulator 84 so as to allow the radially extending wall portions 34 and 46 to come together and slide on each other in frictional contact at atmospheric air pressure for decelerating the rotating ring member 30 while maintaining the narrow axial spacing 52 at the lower flow and pressure to an extent suitable to protect the circular wall portions 26 and 50 from detrimental wear during the deceleration. Wear on the wall portions 34 and 46 is generally of little concern, but wear of even 0.001" on the circular wall portions 26 and 50 would result in a substantial increase in compressed air requirements. Since the ring holder 10 and the rotating ring member 30 are typically machined from brass, it has been found advantageous to apply a thin hard chrome plating layer to the wall portions 46 and 50 thereof in order to have dissimilar metals in bearing contact whenever the narrow spacings 48 and 52 are not maintained by air pressure.
Apparatus embodying the present invention has been experimentally operated on a 4 inch gage Roberts Arrow spinning frame, model of about 1968, operating satisfactorily at spindle speeds up to 16,000 revolutions per minute, spinning 22's cotton count 65% Kodel polyester 35% cotton yarn at 17.48 turns per inch twist. The yarn was spun onto 12 inch length paper tube bobbins to form an approximately two inch diameter yarn package, using Carter Supreme No. 7 travelers on Roberts 21/4 inch spinning rings. Other yarns ranging from 12's to 40's cotton count, such as 50% polyester 50% acrylic, 75% polyester 25% reginned cotton, and 80% polyester 20% silk, have been run experimentally with apparatus embodying the present invention with good results. Specific preferred dimensions of the ring holder 10 and rotating ring member 30 are as follows:
______________________________________Height of ring holder 10: .565 inchesDiameter of bore 26: 2.6262 + .0005 inchesVertical distance from centerof cavity 54 to radiallyextending wall portion 34: .300 inchesHeight of circular wallportion 50: .700 inchesDiameter of circular wall portion50 at lower end: 2.6247 + .0006 inchesDiameter of support flange 32: 3.125 inchesHeight of support flange 32: .175 inchesDiameter of clearance bore 44: 2.250 inchesDiameter of hole 62: .159 inchesDiameter inside flanges ofspinning ring 38: 2.250 inches______________________________________
Whereas the above-described spinning frame is conventionally limited in a particular textile mill to operation at 8,000-10,000 rpm on the above-mentioned yarns by the aforesaid critical or limiting traveler sliding speed of about 5,000 feet per minute and by the particular textile mill's standard of 12 ends down per thousand spindle hours, spinning positions equipped with the air-bearing elements of the present invention appear to operate with ends down reduced over 50% at comparable spindle speeds, and satisfactorily at about 16,000 rpm, limited then only by the capabilities of the spindle bearings and the power drive means. Also such air-bearing equipped spinning positions may be decelerated and stopped from that high speed, also without undue yarn breakage or tangling, by reason of the method and means provided by the present invention for time-delayed reduction of air pressure to the air bearing elements disclosed herein which control yarn tension during stop-off by maintaining suitable predetermined relations between the decelerations of the bobbins and the rotating rings during the stop-off. Typically, the spindles coast about ten seconds after de-energization of the power means, and it has been found advantageous to cut-off the air pressure four to seven seconds after power de-energization, thereby causing the rings to stop about one to three seconds before the spindles stop.
The particular embodiment disclosed in full detail herein and illustrated in the drawings has been provided for disclosure purposes only and is not intended to limit the scope of the present invention, which is to be determined by the scope of the appended claims. We claim:
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An air-bearing supported, freely rotated spinning or twisting ring carrying a yarn traveler having radical and cylindrical air-bearings and an annular plenum cavity in at least one of the cylindrical air-bearing surfaces for generally open, unencumbered and continuous admission of pressurized air to the air-bearings. The air-bearings communicate through an annularly disposed mutually connecting enlarged air space. Time delay means is provided for reducing the air supply to the air-bearings at a selected predetermined time after de-energizing the power drive of the apparatus. A method of controlling yarn tension during stop-off of the apparatus includes the steps of maintaining air pressure in the air-bearings after de-energizing the power drive to the apparatus, continuing to maintain the air pressure while the apparatus and the freely rotating ring decelerate for a predetermined time period, and reducing the air pressure at the end of the time period so that the ring decelerates more rapidly and stops prior to the remainder of the apparatus.
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RELATED APPLICATIONS
The application claims priority to German Application No. 10 2006 023 447.2, which was filed on May 18, 2006.
BACKGROUND OF THE INVENTION
The present invention generally relates to an electromechanical clutch. More particularly, but not exclusively, the present invention relates to an electromechanical ball clutch for use in a power driven system such as a motorized tailgate or hatchback door for a vehicle, for example.
In power driven systems, there is a need to provide a manual back-up mode in case there is a battery failure, for example. Such a manual back-up mode should provide an effort similar to a standard manual system. It is necessary to disengage a drive unit during the manual back-up mode and also when a user wishes to operate the system manually. One way of allowing disengagement of the drive unit is to provide an electromagnetic clutch between mechanical elements, for example between a motor and a reduction unit that benefits from a lower torque provided by the electromagnetic clutch.
In existing systems, clutching is done by clamping two metal plates together with a magnetic force produced by an electromagnetic coil. The transmitted torque is dependent on a coil pull force and a clutch diameter; i.e., the larger the required torque, the bigger the electromagnetic clutch needs to be. Therefore, in order to have an electromagnetic clutch that transfers a large torque, packaging and weight of the electromagnetic clutch must be increased, which is inconvenient and costly. To reduce the power demand on the electromagnetic coil, a permanent magnet can be added in the electromagnetic clutch to work in conjunction with an electromagnet. The permanent magnetic field of this magnet will then create a permanent drag in the system. When this system is used in a tailgate, for example, this drag can be used to hold the tailgate in an intermediate position without having to keep the power on to power the electromagnetic coil. However, the drag caused by the permanent magnet is very uncomfortable for a user operating a tailgate manually in the event of a power failure because the presence of drag means that it is very difficult to open and close the tailgate.
The present invention has been devised with the foregoing in mind.
SUMMARY OF THE INVENTION
Thus, the present invention provides a clutch that includes an input pinion, and an output pinion associated with a rotatable locking member with a surface inclined with respect to an axis of rotation. The surface cooperates with an engagement member, and the rotatable locking member is movable between a first position and a second position. In the first position, the surface forms a recess to receive the engagement member. In the second position, the surface forms a projection to force the engagement member into abutment with the input pinion to establish a driveable connection between the input pinion and the output pinion. The surface amplifies a force that acts on the engagement member, which results in a higher torque that can be transmitted in a small clutch package.
As the rotatable locking member slides from the first position to the second position, the rotatable locking member provides a recess for the engagement member that evolves into a projection in a smooth movement. This can be achieved by having a locking member with a frustro-conical shape or a substantially conical shape with sides tapering inwards towards an end furthest away from the output pinion.
In one example, the input pinion comprises a notch to receive the engagement member so that, when the locking member moves into the second position and pushes the engagement member into engagement with the input pinion, the engagement member engages with the notch. The notches permit the clutch to transmit a higher torque in a much smaller package.
In one example, the locking member and engagement members are ferromagnetic. In this example, the locking member is actuated to move between the first position and the second position by varying a magnetic field. The magnetic field can be provided by an electromagnetic coil. The engagement member can be a ball or a roller.
In one configuration, the locking member is biased in the first position by a spring, which is compressed as the locking member moves from the first position to the second position.
In one example, the clutch further comprises a permanent magnet that assists in holding the locking member in the second position. In the second position, which is also referred to as a closed position, there is only a small air gap between the locking member and the permanent magnet so that the permanent magnet pulls or biases the locking member with a relatively high force into the second position. This allows transmission of a high torque. In the first position, which is also referred to as an open position, the permanent magnet does not have sufficient strength to provide a force that can pull the locking member against a spring force. This is due to a large air gap between the locking member and the permanent magnet. However, the permanent magnet does have sufficient strength to hold the engagement members in contact with the locking member and thereby away from the input pinion when the locking member is in the first position. Thus, the addition of a permanent magnet and a spring gives two stable positions to the clutch in the open and closed positions.
Furthermore, if output of the clutch is maneuvered to reverse the mechanism, a certain amount of torque will be resisted due to the permanent magnetic force and, by virtue of the locking member being connected to the output, the load exerted by both the engagement members to the locking member and a spring compression load will overcome the force of the permanent magnet, and the locking member will return to the open position. To close the clutch again, it is necessary to pass current through the electromagnetic coil in a direction that will generate a magnetic field which, when added to the magnetic field from the permanent magnet, creates a force sufficient to compress the spring such that the locking member moves to the second position and the engagement member is forced into abutment with the input pinion.
To open the clutch electrically, current is passed through the electromagnetic coil in the opposite direction. A repulsive force is then generated by the electromagnetic coil, which cancels or counteracts that of the permanent magnet, and the spring pushes the locking member back to the first position.
The clutch is advantageously used in a mechanism moving an aperture such as a tailgate, a trunk lid, a hatchback or a sliding door, for example. When the mechanism is in a normal automatic mode, the mechanism is driven by a motor, and motor torque is transmitted through the clutch. When the motor is stopped, for example in the event of a power failure or if the user wants the aperture to be held in an intermediate position, the electromagnetic coil can be deactivated. The permanent magnet will produce enough force in the clutch to hold the aperture in the position the aperture was in when the current was stopped. In this position, the aperture can be moved electrically or manually. If the aperture is moved manually, a sensor can be provided in the system, which informs a control system of a manual movement. As soon as the movement stops during a defined time, the control system can activate the electromagnetic coil again so that the locking member is returned to the second position and the clutch is closed. Therefore, in the case of battery failure, even in the middle of an automatic maneuver when the clutch is engaged, the manual maneuver will automatically declutch the system and permit a movement with no drag on the clutch.
Further advantages and characteristics of the invention ensue from the description below, and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a ) is a left side view of a cross-section of a clutch in an open position according to the invention;
FIG. 1 b ) is a right side view of a cross-section of the clutch in a closed position according to the invention;
FIG. 2 a ) is a top left view of the clutch in the open position according to the invention; and
FIG. 2 b ) is a top right view of the clutch in the closed position according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 a )- 1 b ) and 2 a )- 2 b ), a clutch 10 has an input pinion 11 connected to a drive mechanism (not shown), for example an electric motor, which causes the input pinion 11 to rotate. The clutch 10 also has an output pinion 12 that is connected to a moving mechanism (not shown) that moves a tailgate, for example. The output pinion 12 is rotatable about a central axis of rotation A and is arranged to be freely rotatable on a central shaft. The input pinion 11 is provided with notches 19 .
Associated with the output pinion 12 is a frustro-conical locking member 14 that has an inclined surface. The locking member 14 is also rotatable about the central axis of rotation A and is arranged rotatably on the central shaft to be capable of rotating synchronously with the output pinion 12 . The inclined surface of the locking member 14 tapers inwards towards the end of the locking member 14 furthest away from the output pinion 12 . A plurality of engagement members 13 is arranged between an inner surface of the input pinion 11 that has the notches 19 and a conical surface of the locking member 14 . In this example, the engagement members 13 are formed as balls. In order to accommodate the balls, the output pinion 12 has fork-like structures or holes so that the balls are entrained rotationally when the output pinion 12 is rotated.
The locking member 14 is displaceable on the central shaft in a direction that is axial with respect to the central axis of rotation A between a first position that is shown in FIG. 1 a ) and which is referred to as the open position, and a second position that is shown in FIG. 1 b ) and which is referred to as the closed position.
In the first position, the engagement members 13 are in contact with a portion of the inclined surface that has a small diameter. This portion acts like a recess that allows the engagement members 13 to occupy a position that is close to the central axis of rotation A and spaced from the inner surface of the input pinion 11 . In the second position, the engagement members 13 are in contact with a portion of the inclined surface that has a large diameter. This portion acts like a projection that urges the engagement members 13 radially outwards against the inner surface of the input pinion 11 .
A spring 16 is positioned underneath the locking member 14 to bias the locking member 14 into the first position. Further, an electromagnetic coil 15 is provided adjacent to the spring 16 , and a permanent magnet 17 is arranged underneath the spring 16 and the electromagnetic coil 15 . As the engagement members 13 and locking member 14 are made from a ferromagnetic material, the engagement members 13 are held spaced from the notches 19 of the output pinion 12 and in contact with the inclined surface when the locking member 14 is in the first position.
When the moving mechanism is idle, the clutch 10 is in the open position, as shown in FIGS. 1 a ) and 2 a ). The locking member 14 is biased by the spring 16 so that the locking member 14 is in a raised position. This causes the engagement members 13 abutting the locking member 14 to be in contact with a lower part of the locking member 14 towards an apex of the inclined surface. A magnetic loop passing through a housing, the engagement members 13 and the locking member 14 ensures that the engagement members 13 remain in contact with the lower part of the locking member 14 . It can be seen that a lower part of a surface of the locking member 14 provides a recess into which the engagement members 13 fit. Thus, when the locking member 14 is in the raised position, the engagement members 13 are held away from and out of contact with the input pinion 11 , and the input pinion 11 is free to rotate.
When it is required to operate the moving mechanism and close the clutch 10 , as shown in FIGS. 1 b ) and 2 b ), an electric current is applied to the electromagnetic coil 15 . The electromagnetic field produced by the electromagnetic coil 15 then acts on the locking member 14 , which slides downwards in a direction parallel to the central axis of rotation A of the clutch 10 , thereby compressing the spring 16 . As the locking member 14 moves downwards, the locking member 14 slides against the engagement members 13 , pushing them outwards. The locking member 14 thus forces the engagement members 13 towards the input pinion 11 , by virtue of the surface of the locking member 14 being inclined outwards towards a top of the locking member 14 so as to form a wedge. Thus, the surface of the locking member 14 changes from forming a recess to forming a projection. At a maximum compression of the spring 16 , the locking member 14 is at its lowest point with respect to the central axis of rotation A and maximum projection with respect to the engagement members 13 . At this point, the surface of the locking member 14 forces the engagement members 13 into contact with input pinion 11 and then into the notches 19 provided on a circumference of the input pinion 11 .
Thus, as the input pinion 11 rotates, the engagement members 13 are entrained into a rotational movement as they are engaged into the notches 19 . The rotation of the engagement members 13 is transmitted, as the engagement members 13 are accommodated in holes or fork-like configurations of the output pinion 12 , to the output pinion 12 as the locking member 14 prevents the engagement members 13 from escaping from the notches 19 of the input pinion 11 . Finally, the moving mechanism is driven.
The notches 19 provided in the input pinion 11 permit the clutch 10 to have a higher transmitting torque in a much smaller package. The torque transmitted from the input pinion 11 to the output pinion 12 is dependent on the magnetic field generated by the electromagnetic coil 15 ; i.e., the coil pull force, the angle of inclination of the surface of the locking member 14 and the diameter of the engagement members 13 .
The permanent magnet 17 is provided to reduce the required size of the electromagnetic coil 15 and to maintain the clutched position when power is off and forces applied to the clutch 10 are below a limit constituted by the torque plus the spring force tending to declutch. When the clutch 10 is closed, the force provided by the permanent magnet 17 pulls the locking member 14 with a force higher than the compression force of the spring 16 due to a small air gap 18 b (about 0.2 mm), which permits the magnetic field to pass through the locking member 14 . When the clutch 10 is open, the strength of the permanent magnet 17 is not sufficient to generate a force large enough to pull the locking member 14 downwards against the force of the spring 16 . However, the strength of the field from the permanent magnet 17 is sufficient to pass through the engagement members 13 to keep them away from the input pinion 11 .
If power to the electromagnetic coil 15 is cut, or if it is required to operate the moving mechanism manually, the moving mechanism connected to the output pinion 12 can be maneuvered manually. This places a certain torque on the output pinion 12 while the input pinion 11 is braked by motor and gear, for example. The tendency of the output pinion 12 to rotate biases the engagement members 13 out of the notches 19 , resulting in a force that acts on the inclined surface of the locking member 14 in a radial direction. As a result of the inclination of the inclined surface, the radially acting force provides an axial component, which can make the locking member 14 overcome the holding force of the permanent magnet 17 . This causes the locking member 14 to slide up to the raised position, the engagement members 13 to move away from the input pinion 11 , and the clutch 10 to open so that the moving mechanism is no longer connected to the drive mechanism. The clutch 10 can also be opened electrically by passing current through the electromagnetic coil 15 in the opposite direction that causes the clutch 10 to close. This cancels out, or counteracts, the force of the permanent magnet 17 , and the spring 16 can then push the locking member 14 to the raised position such that the engagement members 13 are brought out of contact with the input pinion 11 .
Although the present invention has been described hereinabove with reference to specific embodiments, it is not limited to these embodiments and no doubt alternatives will occur to the skilled person that lie within the scope of the invention as claimed.
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A clutch comprises an input pinion and an output pinion associated with a rotatable locking member that has a surface inclined with respect to an axis of rotation of the locking member. The surface cooperates with an engagement member, and the locking member is movable between a first position and a second position. In the first position, the surface forms a recess to receive the engagement member, and in the second position, the surface forms a projection to force the engagement member into abutment with the input pinion to establish a driveable connection between the input pinion and the output pinion.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to so-called "quick freezing" of solid materials, mainly comestibles, by direct immersion in a liquid refrigerant contained in a sealed vessel.
More specifically, the present invention deals with refrigeration immersion vessels having within their structures an elongated tunnel with movably inclined conveyor means by which solid materials are briefly conveyed through a fluid refrigerant bath of approximately minus 20 degrees Fahrenheit, while allowing no escape of refrigerant vapors from neither the vessel nor the product itself.
2. Discussion of the Prior Art
As it is perhaps well known, there are many diverse commercial, scientific and industrial applications where it is desirable to rapidly freeze materials by directly contacting them with cryogenic or refrigerant fluids, spray or vapors. In virtually all such known applications the material is essentially conveyed through an insulated tunnel of a vessel containing a preferred liquid cryogen or refrigerant, the choice of which largely being dependent on its operating temperature and the speed and degree of freezing desired.
Cryogenic fluids, such as liquid nitrogen, liquid air and liquid carbon dioxide have normal boiling points substantially below minus 100 degrees Fahrenheit, while common refrigerant fluids, such as liquid ammonia and the chlorofluorocarbons (CFC's), have boiling points above minus 100 degrees Fahrenheit and are normally utilized in the temperature range of about -20 degrees F.
In either case, however, the prior art recognizes but fails to solve a major problem of vapor containment within the various vessels as materials are treated therein or, more importantly, from the treated products themselves. Where cryogenic fluids are utilized, it is not environmentally important to contain all of the vapors, but where common refrigerants are used, it is essential that none of their vapors escape into the earth's atmosphere.
Therein lies the distinction and what is believed to be an improvement of the present invention over the prior art.
For example, in U.S. Pat. No. 3,718,284 (1973), Richardson discloses an apparatus and process for embrittling whole used automobile tires prior to crushing and grinding for recycling. This method and apparatus is typical of direct immersion art using cryogenic fluids such as liquid nitrogen, liquid carbon dioxide and liquid air, however such art does not necessarily address containment of vapors from the treated products.
A similar prior art problem of vapor containment is seen in the direct immersion of materials into FREON fluorocarbons (CFC's) as described in U.S. Pat. Nos. 3,440,831 (1969) and 3,774,524 (1973). Although the 1990 Amendments to the Clean Air Act (Title 42, United States Code, Section 7400, et.seq.) require a complete ban on using Class I CFC's by year 2000 (and Class II CFC's by the year 2030), chlorofluorocarbons and, especially CFC-12, are presently in wide use as refrigerants in many commercial applications and dichlorodifluoromethane is presently the liquid refrigerant of choice for direct immersion of comestibles because it is nontoxic, non-corrosive, colorless, odorless, nonflammable and has a boiling point of about -22 degrees Fahrenheit, all of which produces many desired results in a variety of food processing applications. For example, comestibles immersed in liquid dichlorodifluoromethane for a period of time do not stick together and have longer shelf life due to quick freezing which is known to kill bacteria. Thus, it can be easily seen that the utilization of CFC's in food processing alone has several advantages not attainable with cryogenic liquids.
Because of concerns over CFC's damage to the earth's ozone shield that screens out the sun's harmful ultraviolet rays, forty-seven countries in September 1987 agreed to the provisions of the Montreal Protocol on Substances that Deplete the Ozone Layer calling for a ban on consumption of selected CFC's and a 50 percent reduction of them by year 1999. Nonetheless, liquid CFC's are still in wide use and preferred for direct immersion of a variety of materials because of their desirable qualities.
Heretofore, however, there were no suitable immersion vessels specifically designed to contain CFC vapors as pointed out in the prior art.
First, several problem were known with sealing the entrances and exits of these vessels as materials moved in and out of them as thoroughly discussed in U.S. Pat. No. 4,175,396 (1979).
Secondly, there has also been described a persistent problem of re-condensing the voluminous gas produced as vapor in a vessel when a material at ambient temperature was immersed into a cryogenic or refrigerant bath held just below its boiling point, as discussed in U.S. Pat. Nos. 3,768,272 (1973) and 4,928,492 (1990).
Third, known immersion vessels did not specifically address the problem of cryogenic or refrigerant vapors escaping from treated materials after they exited the vessel.
These problems are addressed and solved in the present invention.
SUMMARY OF THE INVENTION
The refrigeration immersion vessel of the present invention is specifically designed to rapidly freeze a variety of materials, especially comestibles, by direct immersion in a liquid bath of CFC's, preferably dichlorodifluoromethane, while preventing any release of CFC vapor into the earth's environment from either the vessel or the treated products.
The vessel may be spatially described as an insulated and sealed horizontally oblong container or tank with entrance and exit ports through which solid materials enter the vessel by way of rotary vane valves as described in detail in previous U.S. Pat. application Ser. No. 07/948,642, filed Sep. 23, 1992, entitled Vapor Locking Rotary Vane Valve For Refrigeration Immersion Vessels, but shall be furthermore described herein.
The interior of the vessel in relation to its horizontal and vertical planes has preferably a lower reservoir directly under its entrance port which contains liquid CFC refrigerant and into which materials are dropped by gravity through a rotary vane valve for quick freezing.
Extending longitudinally from the reservoir and entrance port is an essentially cross-sectionally inverted "U" shaped overhead tunnel with inclined base terminating in an exit port affixed with another rotary vane valve, connected in reverse as the aforesaid entrance valve, for egress of frozen materials free from CFC vapors.
To accomplish movement of solid materials through the vessel's interior, there is preferably positioned a rotatable linear auger, with one end seated near the bottom of the reservoir immersed in liquid refrigerant, but inclined upwardly diagonally and suspended within said tunnel into its upper exit end and terminating directly above the exit port.
Because of the varying densities of materials to be frozen with respect to the density of liquid refrigerant in the reservoir, a shroud is provided partially over the auger forwardly inclined below the entrance port and just above the reservoir refrigerant to trap those materials which would otherwise float between the shroud and auger blades as the auger turns thereby advancing the materials out of the bath and through the tunnel.
A casing of essentially vertical cross-sectional "U" shape longitudinally surrounds very closely, but not in contact with, the entire lower length of the auger thereby providing no escape of solid materials from the auger blades as they capture, submerge and advance said materials through the vessel. The open top of the casing, aside from the shroud, allows escape of vapors from the treated materials while its inclined position provides drainage of liquid refrigerant back into the reservoir.
Condensers, preferably horizontally and linearly mounted above the auger and reservoir, but forward of the entrance port, extend about midway through the vessel thereby providing a means for re-condensing refrigerant vapors from the reservoir and the treated materials. These condensers are internally supplied with another liquid refrigerant from a source external of the vessel, said condenser refrigerant having a lower boiling point that the reservoir refrigerant.
A refrigerant storage tank is also provided externally of the vessel with plumbing connection to vessel reservoir for emptying or filling the vessel reservoir, said plumbing also having a separate heat exchange means in communication with the condenser refrigerant to maintain said reservoir refrigerant below its boiling point.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side elevational diagrammatical schematic view illustrating the general shapes of the essential elements and how they are related to each other.
FIG. 2 is a schematic diagram of the rotary vane valve control system not shown in the other figures.
FIG. 3 is a cross-sectional front perspective view taken along lines 3--3 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before turning to the drawings, it should be briefly pointed out that there is a diversity of opinion as to the extent of harm that CFC's do or do not do to the earth's ozone, as best stated in a recent article entitled "Exposing The Ozone Mythology", HAZMAT WORLD Magazine, Vol. 5, No. 10, October, 1992, pp. 66 to 68. Therefore, the presentation of this invention should not be construed to either endorse nor advocate the use of CFC's for direct immersion of materials therein for quick freezing, but should be presented within the scope and spirit of compliance with numerous governmental rules and regulations concerning containment of CFC fluids and vapors while also providing an apparatus for their continued and legal utilization.
Referring now to FIG. 1 there is a diagrammatically schematic cross-sectional side elevational view of the essential elements of the present invention illustrating their approximate preferred shapes and how they are related to each other, however it should be understood that precise shapes and positing in practice may not be exactly as shown. The vessel 10 itself is preferably of configuration illustrated in FIG. 1 and may spatially described as a horizontally oblong container or tank with horizontal length greater than its maximum vertical height and which may also be described as an elongated tunnel of inverted "U" cross section.
For orientation of FIG. 1, the elongated vessel 10 has a top 11, an entrance end 13 (located at the left of said FIG. 1), and a bottom 12 with inclined base 29 rising diagonally towards an exit end 14. There is also a plateau 15 region of the entrance end 13 about one-half way along its vertical height between said bottom and top.
FIG. 3 illustrates a front perspective view taken from the entrance end 13, partially cut away, to show the tunnel shape of said elongated vessel 10 having an inverted "U" configuration.
Having established the spatial orientation of the vessel and returning to FIG. 1, it can be seen that the vessel 10 has an outer wall 16 and inner wall 17, preferably made of stainless steel although other suitable materials may as well be used, said walls separated by insulation 18.
The plateau 15 of the entrance end 13 of the vessel 10, shown in FIG. 1, has an essentially central entrance port 19 connected externally to a rotary vane valve 20 through which materials enter the vessel as shall be described in more detail hereinafter.
Below the entrance port 19 is a reservoir 21, FIG. 1, in the vessel's 10 lower interior base adjacent to the entrance end 13, and shown by broken lines full of liquid refrigerant to its proper working level. The reservoir 21 is connected by plumbing 22, through the bottom 12 of the vessel 10, with pumps 23 to a storage tank 24 to provide a means of emptying and refilling the vessel 10. It should be pointed out that said plumbing 22, pumps 23 and storage tank 24 may or may not be positioned directly underneath said vessel 10 as shown in FIG. 1 in which structural support or legs have been purposely omitted from the vessel 10 for simplicity of illustration.
Inclined upwardly from the vessel's 10 interior reservoir 21 beginning at a proximate area joining the entrance end 13 and bottom 12, is a linear auger 25 of common construction, inclined diagonally with the base 29 and towards the exit end 14 of the vessel, terminating above the vessel's 10 exit port 27, as shown in FIG. 1. As the auger 25 rotates, its blades 26 propel materials through the vessel 10 upwardly with respect to its longitudinal plane and discharge materials by gravity through the exit port 27 into a rotary vane valve 20 for egress from the vessel 10.
Because of the varying densities of materials entering the vessel's 10 reservoir 21 through the entrance port 19, a shroud 28, shown in FIG. 1, partially covers a portion of the auger 25 submerged in liquid refrigerant (broken lines), to trap those less dense materials under the shroud 28 and below the surface of the liquid refrigerant and between the auger 25 blades 26, which would otherwise tend to float, and the positioning of the shroud 28 in the refrigerant ensures uniform immersion of materials which has been a persistent problem discussed in the prior art.
Although the auger 25 and shroud 28 combination used for submerging materials in a liquid refrigerant is preferred in this embodiment, it should be understood that other immersing and conveying means are known in the art, such as baskets mounted on conveyor chains, which could easily be utilized in the vessel 10 of the present invention, however it is believed that the use of an auger is an improvement due to its simplicity and reduced maintenance requirements because of fewer moving mechanical parts.
To enable advancement of treated materials through the vessel 10 as they exit the reservoir's 21 liquid refrigerant between the blades 26 of the auger 25, a longitudinally elongated casing 30 of essentially vertical cross-sectional "U" shape preferably surrounds very closely, but not in contact with, the entire linear length of the auger 25, as partially shown in both FIGS. 1 and 3, thereby preventing escape of said materials from below and from the sides of rotating auger 25 blades 26 as they capture, submerge and advance the materials through the vessel 10. The open top of the casing 30, apart from the shroud 28, provides for vaporization of refrigerant vapors from the treated products as they travel upwardly through the vessel 10, while the inclined position of the casing 30 also serves as a trough to collect drainage of liquid refrigerant from the materials for return to the reservoir 21 through a plurality of orifices 40 in that part of casing 30 which lies in the reservoir 21, as illustrated in FIG. 1, although greatly exaggerated in size for the purpose of illustration, but in practice large enough to allow passage of liquid refrigerant through the casing 30 by circulation caused by rotating auger 25 blades 26. This constant mixing of liquid refrigerant is believed another important advantage of the present invention over the prior art which has attempted but has largely failed to provide uniform freezing of materials as thoroughly discussed in U.S. Pat. No. 4,852,358 (1989), but in this preferred embodiment the auger 25 not only provides transport of materials through the refrigerant and the vessel, but also continuously stirs and mixes the liquid refrigerant thereby providing uniform temperature in the reservoir 21 bath.
Refrigerant vapors released into the vessel's 10 interior from both the reservoir 21 and treated products by way of the open top of the casing 30, are recondensed by condensers 31, one of which is schematically shown in FIG. 1, preferably affixed and suspended from the top of the vessel's 10 interior linearly in conformance with the vessel's longitudinal length and arranged in a plurality as best illustrated in FIG. 3 in an inverted "U" configuration conforming to the overall cross-sectional shape of the vessel's 10 top.
These condensers 31, being hollow, are supplied internally with a circulating liquid refrigerant, hereinafter called "condenser refrigerant" (as opposed to reservoir refrigerant), said supply source being external of the vessel 10, preferably from a tank 32 and pump 33 to provide continuous circulation of condenser refrigerant through the condensers 31, said condenser refrigerant being of a lower boiling point (colder) that reservoir refrigerant so that any reservoir refrigerant vapors inside the vessel 10 in contact with said condensers 31 will re-liquefy for return to the reservoir 21. The said lower temperature of the condenser refrigerant is maintained by a common external condensing unit 37 with a pump 38, however they need not be located over the top 11 of the vessel 10, but are only illustrated there for simple schematic explanation of their operation, said external condensing unit 37 and pump 38 being of any type commonly employed with similar freezing apparatus as previously described in prior art U.S. Pat. Nos. 4,073,158 (reference numerals 11 and 12), or 4,928,492 (reference numerals 66 and 70), which are herein incorporated by reference and made a part hereof.
FIG. 1 further illustrates yet another use of the condenser refrigerant from external tank 32. By means of pump 34 and plumbing 35 it is also circulated in proximate contact by a heat exchanger 36 as a means of controlling the temperature of the reservoir refrigerant when filling the vessel 10, which is necessary to keep said reservoir refrigerant below its boiling point and liquefied.
Attached externally at the entrance port 19 and exit port 27 of the vessel, illustrated in FIG. 1, are rotary vane valves 20, described in U.S. patent application Ser. No. 07/948,642, filed Sep. 23, 1992. It is the purpose and function of these valves 20 to not only preventing air from entering the vessel 10, but to also prevent refrigerant vapors from escaping from the vessel 10 or treated products themselves.
FIG. 2 schematically diagrams how these valves 20 work in a cross-sectional view with vessel 10 shown in the center of the illustration with reservoir refrigerant 48 (vapor or liquid) in black dots. The rotary vane valves 20 shown at top and bottom of FIG. 2 work under high vacuum which evacuates vapor or liquid from a particular rotating chamber 39 between vanes 40 while allowing solid material 41, shown in clear squares, to enter the valve 20, shown at the top of illustration, along with atmospheric air 42, shown in clear circles.
As the vanes 40 rotate counter-clockwise, as shown in top of FIG. 2, the chamber 39 rotates to a position where it is communicates with vacuum produced by a vacuum pump 43 and plumbing 44 thereby removing the air 42 but leaving the solid material 41 to enter the vessel 10 by gravity through the entrance port 19.
However, it can be seen in FIG. 2 that some refrigerant will always naturally diffuse into an open compartment 39 and said compartment must then be evacuated at yet another position by communication with vacuum produced by a vacuum pump 45 and plumbing 46 connected to the vessel 10 for recycling of the refrigerant 48, thereby preventing its escape into the atmosphere.
As treated material 47, shown in solid squares, exit the vessel 10 through exit port 27, some refrigerant vapor 48 will diffuse into chamber 39 and may remain on said material 47 as a residue. The chamber 39 is first rotated to a first position for communication with high vacuum caused by vacuum pump 49 and plumbing 50, (as illustrated in FIG. 2 at bottom and left) connected to the vessel 10 for evacuation of the chamber 39 and recycling of refrigerant back into the vessel 10.
As treated material 47 is discharged from the valve 20, as illustrated at the bottom of FIG. 2, atmospheric air 42 will once again naturally diffuse into a compartment 39 and is subsequently evacuated therefrom as said compartment is further rotated into vacuum communication with pump 51 and plumbing 52, which prevents air from entering the vessel 10 through the exit port 27.
To those skilled in the art it may be obvious that four vacuum pumps 43, 45, 49 and 51 are not necessary for the operation of the valves 20, if plumbing 44, 46, 50 & 52 would have been shown more efficiently combined, for example by way of a manifold. However, it should be recognized that FIG. 2 schematic is presented for ease of understanding the principle of the valves operation and not as a plumbing diagram.
Referring now to FIG. 3, a cross-sectional front perspective view taken along lines 3--3 of FIG. 1, there are seen the essentially vertical sides 53 of the vessel 10 with dome-shaped top 11, comprising in inverted "U" shape with a flat bottom 12, all of which having the appearance of a tunnel as previously stated. Insulation 18 is shown in diagonal lines between the outer wall 16 and inner wall 17, and a preferred positioning of a plurality of condensers 31, are schematically illustrated interconnected to each other for internal circulation of condenser refrigerant supplied externally from tank 32 pump 33 through the vessel's 10 dome 11, however it should be emphasized once again that positioning of said tank 32 and pump 33 on top 11 of the dome are for purposes of schematic illustration only and for ease of understanding operation of condensing and keeping cold the vessel's reservoir refrigerant by external and colder condenser refrigerant, and in actual practice said tank 32 and pump 33 are not located on top of the vessel 10.
One further purpose of the condenser refrigerant, illustrated in FIG. 3 and not in the other figures, is its circulation by pump 34 and appropriate plumbing 55 through a heat transfer plate 54 lining the bottom of reservoir 21 thereby keeping the reservoir refrigerant cold.
Also shown in FIG. 3 is the preferred position of the auger 25, portion of the shroud 28 and auger blades 26 partially enclosed in its casing 30, all of which are perspectively inclined from the reservoir 21 upwardly along the inclined base 29 of the tunnel toward its exit end 14, shown in FIG. 1.
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A refrigeration immersion vessel primarily designed for direct immersion of comestibles into liquid chlorofluorocarbons (CFC's) at approximate minus 20 degrees Fahrenheit is described wherein said vessel employs pairs of rotary vane valves with internal vacuum in communication with a closed system to recycle CFC vapors into said vessel while preventing atmospheric air from entering it, said vessel further utilizing different CFC from a source external of the vessel and of lower boiling point to maintain temperature of vessel reservoir refrigerant, said vessel also having condensers using the external CFC refrigerant for recondensing internal CFC vapors, controlling vessel reservoir temperature and temperature of vessel refrigerant storage outside said vessel, said vessel further comprising an inclined internal conveyor means and bottom for drainage by gravity of excess refrigerant into its reservoir.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to Japanese Patent Application No. 2009-3940, filed Jan. 9, 2009, of which full contents are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a motor driving circuit.
[0004] 2. Description of the Related Art
[0005] Some motor driving circuits may keep the amounts of currents flowing through motor coils at set levels by controlling on and off of transistors connected to the motor coils (Japanese Patent Application Laid-Open Publication No. 2005-184897). For example, in a motor driving circuit shown in FIG. 5 , an energization state of a motor coil M connected between terminals T 1 and T 2 is controlled by on and off of N-channel MOSFETs 110 to 113 making up an H-bridge. For example, in a drive control circuit 120 , the N-channel MOSFETs 110 and 113 are turned on and the N-channel MOSFETs 111 and 112 are turned off, so that the circuit passes the current through a path of the N-channel MOSFET 110 , the motor coil M, and the N-channel MOSFET 113 , to drive the motor (driving state). The amount of the current flowing through the motor coil M is detected by a resistor R connected via a terminal T 3 and when the amount of the current flowing through the motor coil M reaches the set level, the drive control circuit 120 turns off the N-channel MOSFET 110 and turns on the N-channel MOSFET 111 . As a result, the current, which the motor coil M tries to continue passing, is regenerated by a loop of the N-channel MOSFET 111 , the motor coil M, and the N-channel MOSFET 113 , and decreases gradually (regeneration state). As such, the drive control circuit 120 is capable of maintaining the amount of the current flowing through the motor coil M at the set level by repeating the driving state and the regeneration state.
[0006] Incidentally, in the motor driving circuit, a load may be short-circuited due to aged deterioration of the motor, for example. In the motor driving circuit shown in FIG. 5 , if the load is short-circuited, an overcurrent occurs in a case where the energization state of the motor coil M is the driving state, and if the overcurrent is over the set level of the current flowing through the motor coil M, the drive control circuit 120 changes the energization state of the motor coil M to the regeneration state. Then, after elapse of a predetermined time, the drive control circuit 120 changes the energization state of the motor coil M to the driving state, and the driving state and the regeneration state are repeated despite the load is short-circuited. Since the motor driving circuit is generally provided with an overheat protection function, circuit operation stops before causing circuit failure even if the driving state and the regeneration state are repeated in a state where the load is short-circuited. It is desirable, however, to detect a short circuit of the load and protect the circuit before it becomes in such an overheated state.
SUMMARY OF THE INVENTION
[0007] A motor driving circuit according to an aspect of the present invention, comprises: a first transistor on a power source side and a second transistor on a ground side connected in series; a third transistor on the power source side and a fourth transistor on the ground side connected in series; a drive control circuit configured to control a energization state of a motor coil so as to be a driving state where either one group of a group of the first and fourth transistors and a group of the second and third transistors is on and the other group is off, or so as to be a regeneration state where the first and third transistors are off and the second and fourth transistors are on, the motor coil connected to a connection point of the first and second transistors and a connection point of the third and fourth transistors; a set current detection circuit configured to detect whether an amount of current flowing through the motor coil has reached a set level; an overcurrent detection circuit configured to detect an overcurrent state where an amount of current flowing through any of the first to fourth transistors is over a predetermined amount of current; and an overcurrent protection circuit configured to output a regeneration instruction signal for shifting the energization state to the regeneration state in a case where the overcurrent state does not occur and output a drive stop signal for stopping driving the motor coil in a case where the overcurrent state occurs, when the amount of current flowing through the motor coil has reached the set level in the driving state, the drive control circuit shifting the energization state to the regeneration state to be maintained for a predetermined time period and thereafter returning the energization state to the driving state when the regeneration instruction signal is output, and turning off the first to fourth transistors when the drive stop signal is output.
[0008] Other features of the present invention will become apparent from descriptions of this specification and of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For more thorough understanding of the present invention and advantages thereof, the following description should be read in conjunction with the accompanying drawings, in which:
[0010] FIG. 1 is a diagram of a configuration of a motor driving circuit according to an embodiment of the present invention;
[0011] FIG. 2 is a timing chart of one example of an operation when a load is short-circuited;
[0012] FIG. 3 is a timing chart of one example of an operation when a short circuit to a high voltage point occurs;
[0013] FIG. 4 is a timing chart of one example of an operation when a short circuit to ground occurs; and
[0014] FIG. 5 is a diagram of a configuration example of a general motor driving circuit.
DETAILED DESCRIPTION OF THE INVENTION
[0015] At least the following details will become apparent from descriptions of this specification and of the accompanying drawings. FIG. 1 is a diagram of a configuration of a motor driving circuit 10 according to an embodiment of the present invention. The motor driving circuit 10 includes N-channel MOSFETs 20 to 23 , a drive control circuit 30 , comparators 32 to 36 , reference sources 40 to 42 , NAND circuits 45 though 52 , an AND circuit 54 , NOR circuits 56 and 57 , a NOT circuit 58 , counters 60 and 61 , and a SR flip-flop 63 .
[0016] The N-channel MOSFETs 20 to 23 make up an H-bridge circuit, and a motor coil M is connected, via terminals T 1 and T 2 , between a connection point of the N-channel MOSFET 20 (first transistor) and the N-channel MOSFET 21 (second transistor) and a connection point of the N-channel MOSFET 22 (third transistor) and the N-channel MOSFET 23 (fourth transistor). The motor coil M is a DC motor coil, for example, and current flows through the motor coil M in a direction from the terminal T 1 to the terminal T 2 so as to rotate a motor in a positive direction (positive rotation) and the current flows through the motor coil M in a direction from the terminal T 2 to the terminal T 1 so as to rotate the motor in a reverse direction (reverse rotation).
[0017] The drive control circuit 30 controls on and off of the N-channel MOSFETs 20 to 23 so that the amount of the current flowing through the motor coil M reaches a set level, according to the direction of the motor rotation. For example, in the case of the positive rotation, the drive control circuit 30 firstly turns on the N-channel MOSFETs 20 and 23 and turns off the N-channel MOSFETs 21 and 22 . Thus, the current flows through a path of the N-channel MOSFET 20 , the motor coil M, and the N-channel MOSFET 23 . A state in which the current flows through this path is referred to as a driving state. When the amount of the current flowing through the motor coil M reaches a set level, the drive control circuit 30 turns off the N-channel MOSFET 20 and turns on the N-channel MOSFET 21 . Thus, the current flowing through the motor coil M is regenerated in a loop of the N-channel MOSFET 21 , the motor coil M, and the N-channel MOSFET 23 . A state in which the current flows through this path is referred to as a regeneration state. In the case of the reverse rotation, the current flows through the path of the N-channel MOSFET 22 , the motor coil M, and the N-channel MOSFET 21 in the driving state, and the current flows in the loop of the N-channel MOSFET 23 , the motor coil M, and the N-channel MOSFET 21 in the regeneration state. Furthermore, when detecting overcurrent caused by a short circuit to a high voltage point, a short circuit to ground, or a short circuit of a load, the drive control circuit 30 turns off all of the N-channel MOSFETs 20 to 23 .
[0018] The comparator 32 is a circuit for detecting whether the amount of the current flowing through the motor coil M has reached the set level when the motor coil M is in the driving state. Specifically, the comparator 32 outputs a comparison result of a voltage Vrf generated by the current flowing through a resistor R connected via the terminal T 3 and a reference voltage Vref 1 according to the set level output from the reference source 40 .
[0019] The comparator 33 and the NAND circuit 45 make up an overcurrent detection circuit for detecting whether the current flowing through the N-channel MOSFET 20 is the overcurrent. In an embodiment according to the present invention, a voltage Vm-Vref 2 that is lower by a reference voltage Vref 2 of the reference source 41 than the power source Vm is applied to a positive input terminal of the comparator 33 . A negative input terminal of the comparator 33 is connected to the source of the N-channel MOSFET 20 . Therefore, in a state where a signal N 1 goes high and the N-channel MOSFET 20 is turned on, if the overcurrent occurs in the N-channel MOSFET 20 due to the short circuit of the terminal T 1 to the ground or occurrence of the short circuit of the load, for example, a voltage drop occurs in the N-channel MOSFET 20 becomes greater than Vref 2 , the output of the comparator 33 goes high, and the output of the NAND circuit 45 goes low. Similarly, the comparator 34 and the NAND circuit 46 make up an overcurrent detection circuit for detecting whether the current flowing through the N-channel MOSFET 22 is the overcurrent.
[0020] The comparator 35 and the NAND circuit 47 make up an overcurrent detection circuit for detecting whether the current flowing through the N-channel MOSFET 21 is not overcurrent. In an embodiment according to the present invention, the positive input terminal of the comparator 35 is connected to the drain of the N-channel MOSFET 21 and the negative input terminal of the comparator 35 is applied with a voltage which is higher by a reference voltage Vref 3 of the reference source 42 than the voltage of the source of the N-channel MOSFET 21 . Therefore, in a state where a signal N 2 goes high and the N-channel MOSFET 21 is turned on, if the overcurrent occurs in the N-channel MOSFET 21 due to the short-circuit of the terminal T 1 to a high voltage point, for example, the voltage drop occurs in the N-channel MOSFET 21 becomes greater than Vref 3 , the output of the comparator 35 goes high, and the output of the NAND circuit 47 goes low. Similarly, the comparator 36 and the NAND circuit 48 make up an overcurrent detection circuit for detecting whether the current flowing through the N-channel MOSFET 23 is the overcurrent.
[0021] The output signals of the NAND circuits 45 to 48 are input to the AND circuit 54 . Therefore, if the overcurrent occurs in any of the N-channel MOSFETs 20 to 23 , then any of the outputs of the NAND circuits 45 to 48 goes low so that the output of the AND circuit 54 goes low.
[0022] To the NAND circuit 49 , the signal N 1 to be input to the gate of the N-channel MOSFET 20 and a signal for instructing the positive rotation or reverse rotation, which is input from an input terminal IN 1 , are input. To the NAND circuit 50 , the signal N 3 to be input to the gate of the N-channel MOSFET 22 and a signal obtained by inverting by the NOT circuit 58 the signal input from an input terminal IN 1 are input. In an embodiment according to the present invention, the signal input from the input terminal IN 1 goes high in the case of the positive rotation and goes low in the case of the reverse rotation. Therefore, in the case of the positive rotation, the output of the N-channel MOSFET 50 is always high and the output of the N-channel MOSFET 49 is low only during a time period in which the signal N 1 is high. Similarly, in the case of the reverse rotation, the output of the N-channel MOSFET 49 is always high and the output of the N-channel MOSFET 50 is low only during a time period in which the signal N 3 is high. Since the output signals of the NAND circuits 49 and 50 are input to the NAND circuit 51 , the output of the NAND circuit 51 is high when the energization state of the motor coil M is the driving state, in either case of the positive rotation or the reverse rotation.
[0023] The counter 60 (minimum time count circuit) is a circuit for counting the minimum time of a time during which the energization state of the motor coil M is the driving state. In an embodiment of the present invention, when the energization state of the motor coil M becomes the driving state, the output of the NAND circuit 51 goes high. Therefore, the counter 60 starts counting when the output of the NAND circuit 51 goes high, and changes the level of the output signal to the high level when a count value reaches a value corresponding to the minimum time. The count value of the counter 60 is reset when the output of the NAND circuit 51 goes low.
[0024] The counter 61 is a circuit for counting a mask time from a time when the overcurrent is detected until a time when a state is shifted to a protective state. In an embodiment of the present invention, the output signal of the AND circuit 54 and the output signal from an output terminal Q of the SR flip-flop 63 are input to the NOR circuit 56 , and when both of these two signals go low, the output of the NOR circuit 56 goes high. The counter 61 starts counting when the output of the NOR circuit 56 goes high and changes the level of its output signal to the low level when a count value reaches a value corresponding to the mask time. The count value of the counter 61 is reset when the output of the NOR circuit 56 goes low before the count value reaches the value corresponding to the mask time. When the output signal of the counter 61 goes low, the drive control circuit 30 determines the presence of the overcurrent state and turns off all of the N-channel MOSFETs 20 to 23 . Here, the low-level signal output from the counter 61 is one example of a drive stop signal according to the present invention.
[0025] In the SR flip-flop 63 , the output signal of the counter 61 is input to the inverting set terminal /S thereof and the signal input from the input terminal IN 2 is input to its inverting reset terminal /R thereof. Therefore, when the signal input to the inverting set terminal /S goes low, the signal output from the output terminal Q goes high and the signal output from the inverting output terminal /Q goes low, and when the signal input to the inverting reset terminal /R goes low, the signal output from the output terminal Q goes low and the signal output from the inverting output terminal /Q goes high. The signal input from the input terminal IN 2 goes low at the time of start-up of the motor driving circuit 10 and thereafter maintains the high level. Therefore, the signals output from the output terminal Q and the inverting output terminal /Q of the SR flip-flop 63 are low and high, respectively, at the initial state. Thereafter, when the signal output from the counter 61 goes low, the signals output from the output terminal Q and the inverting output terminal /Q of the SR flip-flop 63 go high and low, respectively.
[0026] The output signal of the counter 60 , the output signal of the AND circuit 54 , and the signal output from the inverting output terminal /Q of the SR flip-flop 63 are input to the NAND circuit 52 . Therefore, only when all of these three signals are high, the output signal of the NAND circuit 52 goes low. The signal output from the NAND circuit 52 and the signal output from the comparator 32 are input the NOR circuit 57 . Therefore, only when both of these two signals are low, the signal output from the NOR circuit 57 goes high. When the signal output from the NOR circuit 57 goes high in a case where the energization state of the motor coil M is the driving state, the drive control circuit 30 changes the energization state to the regeneration state. Here, the high-level signal output from the NOR circuit 57 is one example of a regeneration instruction signal according to the present invention.
[0027] The circuit including the NAND circuits 49 to 52 , the NOR circuits 56 and 57 , the NOT circuit 58 , the counters 61 and 62 , and the SR flip-flop 63 correspond to one example of an overcurrent protection circuit according to the present invention.
[0028] FIG. 2 is a timing chart of one example of an operation when the load is short-circuited. It is assumed that the short circuit of the load does not occur in the initial state. At the beginning, all of the signals N 1 to N 4 input to the gates of the N-channel MOSFETs 20 to 23 are low and the N-channel MOSFETs 20 to 23 are off.
[0029] Thereafter, at a time T 1 , when the signals N 1 and N 4 go high, the energization state of the motor coil M is changed to the driving state and the amount of the current flowing though the motor coil M increases. When the signal N 1 goes high, the counter 60 starts counting; and at a time T 2 , when a count value reaches a value corresponding to the minimum time of the driving state at a time T 2 , the signal B output from the counter 60 goes high. At this time, since the overcurrent does not occur, the signal A output from the AND circuit 54 is high, and since the SR flip-flop 63 is in the initial reset state, the signal D output from the inverting output terminal /Q is also high. Therefore, all of the signals A, B, and D input to the NAND circuit 52 are high and the signal E output from the NAND circuit 52 is changed to the low level.
[0030] Thereafter, the amount of the current flowing through the motor coil M continues to increase and at a time T 3 , when it reaches the set level set by the power source 40 , the signal F output from the comparator 32 is changed to the low level. At this time, since the signal E is also low, both of the signals E and F input to the NOR circuit 57 are low and the signal G output from the NOR circuit 57 is changed to the high level.
[0031] When the signal G goes high, the drive control circuit 30 determines that the amount of the current flowing through the motor coil M has reached the set level, and at a time T 4 , allows the signal N 1 to be changed to the low level and the signal N 2 to be changed the high level, and thus, the energization state of the motor coil M is changed to the regeneration state. Due to the signal N 1 being changed to the low level, the counter 60 is reset and the signal B is changed to the low level. Due to the signal B being changed to the low level, the signal E goes high and the signal G goes low.
[0032] After elapse of a predetermined time of the regeneration state, the drive control circuit 30 allows the signal N 1 to be changed to the high level and the signal N 2 to be changed to the low level at a time T 5 . Thus, the energization state of the motor coil M is changed again to the driving state. At this time, if it is assumed that the short circuit of the load occurs, the amount of the current flowing through the motor coil M rapidly increases. At a time T 6 , when the amount of the current flowing through the motor coil M reaches the set level, the signal F is changed to the low level. Furthermore, the short circuit of the load causes the overcurrent in the N-channel MOSFET 20 or the N-channel MOSFET 23 , and thus the signal A is changed to the low level at time T 7 .
[0033] When the signal N 1 goes high, the counter 60 starts counting and the signal B is changed to the high level at a time T 8 . At this time, out of the signals A, B, and D input to the NAND circuit 52 , the signals B and D are high, however, the signal A is low due to the occurrence of the overcurrent. Therefore, the signal E remains high and the signal G remains low. As a result, although the amount of the current flowing through the motor coil M has reached the set level, the signal G remains low, and thus, the drive control circuit 30 keeps the energization state of the motor coil M in the driving state.
[0034] When the signal A goes low, the signal output from the NOR circuit 56 goes high and the counter 61 starts counting. Thereafter, at a time T 9 , when the count value of the counter 61 reaches the count value corresponding to the mask time, the signal C is changed to the low level. When the signal C goes low, the drive control circuit 30 determines that the signal A is low because of the occurrence of the overcurrent not because of the effect of the noises, etc., and allows all of the signals N 1 to N 4 to be changed to the low level. As a result, the motor coil M stops driving and the overcurrent state is eliminated.
[0035] FIG. 3 is a timing chart of one example of an operation when the short circuit to the high voltage point occurs. Here, it is assumed that the terminal T 1 is short-circuited to the high voltage point. In the initial state, all of the signals N 1 to N 4 are low and the drive control circuit 30 allows the signals N 1 and N 4 to be changed to the high level at a time T 11 . Thus, the energization state of the motor coil M is changed to the driving state. As in the case of FIG. 2 , the signal B goes high and the signal E goes low at a time T 12 and the signal F goes low and the signal G goes high at a time T 13 .
[0036] When the signal G goes high, the drive control circuit 30 allows the signal N 1 to be changed to the low level and the signal N 2 to the high level at a time T 14 , as in the case of FIG. 2 . As a result, the N-channel MOSFET 21 is turned on, however, since the terminal T 1 is short-circuited to the high voltage point, the overcurrent occurs in the N-channel MOSFET 21 . Therefore, the signal F goes low at a time T 15 and the signal A goes low at a time T 16 . After elapse of the mask time from the time T 16 , the signal C is changed to the low level at a time T 17 . As at result, the drive control circuit 30 allows the signals N 1 to N 4 to be changed to the low level and the overcurrent state is eliminated.
[0037] FIG. 4 is a timing chart of one example of an operation when the short circuit to the ground occurs. Here, it is assumed that the terminal T 1 is short-circuited to the ground. In the initial state, all of the signals N 1 to N 4 are low, and at a time T 21 , the drive control circuit 30 allows the signals N 1 and N 4 to be changed to the high level. As a result, the N-channel MOSFET 20 is turned on, however, since the terminal T 1 is short-circuited to the ground, the overcurrent occurs in the N-channel MOSFET 20 . At this time, the signal F remains high since no current flows through the resistor R, however, the signal A is changed to the low level at a time T 22 since the overcurrent occurs in the N-channel MOSFET 20 .
[0038] Thereafter, as in the case of FIG. 2 , the signal B is changed to the high level and the signal E is changed to the low level at a time 23 . Then, when the mask time has passed since the signal A went low, the signal C is changed to the low level at a time T 24 . As a result, the drive control circuit 30 allows all of the signals N 1 to N 4 to be changed to the low level and the overcurrent state is eliminated.
[0039] As above, in the motor driving circuit 10 according to an embodiment of the present invention, when the amount of the current flowing through the motor coil M has reached the set level, it is shifted to the regeneration state in the case where the overcurrent does not occur, and it is not changed to the regeneration state but the overcurrent protection function is performed in the case where the overcurrent occurs. Therefore, when the load is short-circuited, there is no repetition of the driving state and the regeneration state, and thus safety when the load is short-circuited may be improved. In the motor driving circuit 10 , the overcurrent protection function is performed not only in the case of the short circuit of the load but also in the case of the short circuit to the high voltage point and the short circuit to the ground.
[0040] In the motor driving circuit 10 , the mask time of the overcurrent is set by the counter 61 . Therefore, it becomes possible to control stop of the drive of the motor coil M, when noise is caused in the signal A, for example.
[0041] In the motor driving circuit 10 , the minimum time in the driving state is set by the counter 60 , and even in such a configuration, the overcurrent protection function may appropriately be performed in any case of the short circuit of the load, the short circuit to the high voltage point, or the short circuit to the ground.
[0042] The above embodiments of the present invention are simply for facilitating the understanding of the present invention and are not in any way to be construed as limiting the present invention. The present invention may variously be changed or altered without departing from its spirit and encompass equivalents thereof.
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A motor-driving-circuit comprising: a first to-fourth-transistors; a drive-control-circuit to control a energization-state of a motor coil so as to be a driving-state where either one group of a groups of the first-and-fourth-transistors and the second-and-third-transistors is on and the other group is off, or so as to be a regeneration-state where the first-and-third-transistors are off and the second-and-fourth-transistors are on; a set-current-detection-circuit; an overcurrent-detection-circuit; and an overcurrent-protection-circuit to output a regeneration-instruction-signal for shifting the energization-state to the regeneration-state if an overcurrent-state does not occur and output a drive-stop-signal for stopping driving the coil if the overcurrent-state occurs, when a current amount flowing through the coil has reached a set-level in the driving-state, the drive-control-circuit shifting the energization-state to the regeneration-state to be maintained for a predetermined time period and thereafter returning the energization-state to the driving-state when the regeneration-instruction-signal is output, and turning off the first-to-fourth-transistors when the drive-stop-signal is output.
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BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is the side view of the tag attaching apparatus in the present invention.
FIG. 2 is the side view of the tag attaching apparatus in the present invention, illustrating in detail the operating state of the subject matters characterized by the present invention.
DETAILED DESCRIPTION OF INVENTION
This invention relates to the means for supplying the fasteners in a tag attaching apparatus. In a tag attaching apparatus, the present invention contains characteristically the -type plunger as well as the pushing member and the pushing bar so that, every time when the lever is pushed and released, since the pushing bar induces one step of the rotation of the gear wheel, it is possible to supply regularly the fasteners one by one.
According to the prior arts, since the tag attaching apparatus contains the fasteners supplying means consisting of a complicated constructions, it has the defects that the cost to produce the apparatus is expensive and the apparatus has been broken down frequently.
According to the present invention, in a common tag attaching apparatus, in order to reform the operating system of the fastener supplying means to a simple one, the invention contains characteristically that, by connecting to the fastener supplying gear wheel the -type plunger located on the upper part of the hinge portion driving in the driving home and having the pressing pole pressing the fastener into the concave home of the needle, the pushing member locates on the central part of the plunger and the pushing bar connected to the pushing member. And, when the lever is pushed, by the forward driving of the plunger, the pressing bar pushes the fastener into the concave home of the needle and the tag is attached to the goods. Since the gear wheel is turned by each step caused by the mutual combination between the plunger, the pushing member and the pushing bar, it is possible to supply the fasteners one by one to the needle. And, the construction is very simple and the manufacture is easy so that the present invention is used conveniently and for a long time without causing any obstacle during the use.
The present invention is described in detail, according to the accompanying drawings, as follows:
In a common tag attaching apparatus having that the needle (2) excavated the concave home (2') is installed on the edge of the frame (1), the fastener supply gear wheel (3) is installed on the one side of the needle (2) and the fastener (5) is supplied in a line into the guiding aperture (4) located on between the gear wheel (3) and the needle (2), the present invention contains characteristically that the plunger (8) having the edge portions (8') and (8") which drives to the forward direction and to the backward direction in the driving home (7) by the hinge portion (6') is located on the upper part of the driving home (7) of the hinge portion (6') having the pressing pole (6); the bottom of the pushing member (9) is hinged on the base (9') located on the upper part of the central part of the plunger (8); the pushing bar (10) connected to the upper part of the pushing member (9) is pressed to touch with the gear wheel (3) by the spring (11); and, since the unloosing member (13) is located on the front edge of the frame (1) and, when the unloosing member (13) is pushed upwardly, the locking member (12) is separated from the gear wheel (3).
According to the present invention, the tag is attached to the goods by a common way and, however, when the lever (14) is pushed, the hinge portion (6') moves forwardly by the hinge support (15) so that the pressing pole (6) pushes one of the fasteners (5) into the concave home (2') of the needle (2) and, when the tag is attached to the goods, the edge portion (8') of the plunger (8) drives a little by the hinge portion (6') during the driving of the hinge portion (6') and the upper part of the pushing member (9) moves on the opposite direction. After the tag is attached, when the lever (14) is released, the hinge portion (6') returns to the original state and the edge portion (8") of the plunger (8) is driven to the opposite direction by the hinge portion (6'). Then, the upper part of the pushing member (9) causes to return to the opposite direction and, since the pushing member (9) causes the movement of the pushing bar (10) and the gear wheel (3) is turned, one of the fasteners (5) is supplied to the needle.
As explained above, it is notable that the present invention contains characteristically the pushing bar (10), the pushing member (9) and the -type plunger (8) consisting of the edge portions (8") and (8') having the pressing pole (6) and locating on the upper part of the hinge portion (6') moving in the space of the driving home (7) and, by the mutually connected operation of the plunger (8), the pushing member (9) and the pushing bar (10) caused by the movement of the hinge portion (6'), the gear wheel (3) supplying the fasteners (5) is driven.
There is the effect that the construction is so simple that the manufacture is very easy and the operation is exact and the present invention can be used conveniently for a long time without any obstacle.
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A tag attaching apparatus including a frame (1), a hollow needle (2) for attaching fasteners (5), a fastener supply gear wheel (3), a plunger (8) the sliding motion of which actuates a bell crank mechanism for incrementing the fastener supply gear wheel (3), and a pawl (12) which prevents reverse motion of the fastener supply gear wheel (3).
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BACKGROUND OF THE INVENTION
The present invention relates to a method of producing a knitted article on a flat knitting machine.
For a rational manufacture of knitted articles, in particular in clothing industry, it is today required to provide as many manufacturing steps as possible on a knitting machine, so that only a few subsequent steps or no steps at all are needed. In the case of articles of clothing with fasteners, only a knitting of button holes on the knitting machine was performed. By means of a widening technique approximately round button holes can be produced. Longitudinal slot-shaped button holes can be formed by intarsia technique and horizontal slot shaped button holes can be performed by a looping technique. The buttons which correspond to the button holes must be sewn however in an additional working step. It has been recognized that the button which must be placed at the same height as the associated button hole requires a corresponding attention and therefore can be performed in a machine to a very limited extent.
On the other hand, fasteners on clothing articles are frequently needed, for example in form of buttons or button hole strips on cardigans, on reverse sides of a pullover, or on hand cuffs or pocket slots.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method for producing knitted articles and a knitted article produced by it, which do not need or need only a few subsequent steps.
In keeping with these objects and with others which will become apparent hereinafter, one feature resides, briefly stated in a method of producing a knitted article on a flat knitting machine with at least two needle beds, wherein the knitted article has at least one button-shaped stitch structure as a fastener element, and the at least one button-shaped knitted structure is transformed by a local stitch aggregation into several successive knitting rows. With this button-shaped stitch structures, corresponding button holes which can be formed for example round, can be made by known widening technique.
For forming the button-shaped stitch structure, the following steps preferably can be performed:
A. Forming of stitches for a button-shaped stitch structure on one needle bed and forming tuck loops on the opposite needles of the other needle bed;
B. In both next knitting rows, forming of stitches for the button-shaped stitch structure and of tuck loops for left and right edge stitches of the button-shaped stitch structure, which have no connection to a basic knitted article;
C. Subsequently, forming of knitting rows with stitches and tuck loops in an alternating order, until the button-shaped stitch structure reaches a desired size;
D. Forming a knitting row with stitch formation on both needle beds;
E. Hanging the left edge stitch to a stitch of the basic knitted article;
F. Repeating the steps D and E for the right edge stitch;
G. Knitting a safety knitting row.
The present invention deals also with a second method of producing a knitted article on a flat knitting machine with at least two needle beds, wherein the knitted article has at least one stitch structure as a fastening element serving as a sleeve for an insertable solid body, and at least one stitch structure produced by a wedge shaping technique and closeable by a knitted-in knot thread. For producing this stitch sleeve the following steps can be preferably performed:
A. Insertion of a knot thread by means of a tuck loop in each second needle of a needle bed over a needle region whose width corresponds to the maximum diameter of the stitch structure;
B. Forming a short starting row for the stitch structure and connecting this stitch row with the knitted article by means of a tuck loop;
C. Forming further stitch rows for the stitch structure and connecting with the knitted article via a tuck loop, wherein the stitch structure is progressively alternatingly expanded at both sides until its maximum diameter is reached;
D. Forming at least two stitch rows, wherein correspondingly the edge stitch is not knitted off;
E. Forming stitch rows with progressive alternating-side reduction of the stitch number and connecting the stitch rows with the knitted article by tuck loops;
F. Inserting the warp thread by means of tuck loops in each second needle of the other needle bed over a needle region which corresponds to the maximum diameter of the stitch structure so that the knot threads are laid U-shaped around the stitch structure.
In this sleeve, subsequently a solid body can inserted, for example a button, and the sleeves are then closed by contraction and knotting of the knot thread. This type of the fastener element can also cooperate with various button holes. Instead of the button holes, loop-shaped fastener elements can be provided.
The invention also deals with a method for producing a knitted article on a flat knitting machine with at least two needle beds, wherein the knitted article has at least one loop-shaped stitch structure as a fastener element, which is formed by a small knitted strip connected at both ends with the knitted article. This fastener element can serve however not only for the receipt of the button-shaped stitch structure or the enveloped solid body or also conventional button, but also can be provided for example with tongues and cooperate with other loop-shaped fastener elements. The loop-shaped stitch structure can be formed for example by knitting only with each second needle, wherein the knitting and knot knitting needles alternate in each stitch row.
In addition to the above described methods, the present invention also deals with a knitted article which is produced by these methods.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a view showing a section taken along the line A—A through a knitted article of FIG. 1 b;
FIG. 1 b is a partial view of a knitted article with a first fastener type in accordance with the present invention;
FIG. 1 c is a view showing a cross-section through the closed knitted article of FIG. 1 b;
FIG. 2 a is a view showing a section taken along the line A—A through the knitted article of FIG. 2 b;
FIG. 2 b is a detailed view of a knitted article with a second fastener type;
FIG. 2 c is a view showing a cross-section through the closed knitted article of FIG. 2 b;
FIG. 3 a is a view showing a section taken along the line A—A through the knitted article of FIG. 3 b;
FIG. 3 b is a detailed view of a knitted article with a third fastener type;
FIG. 3 c is a view showing a cross-section through the closed knitted article of FIG. 3 b;
FIG. 4 a is a view showing the section along the line A—A through the knitted article of FIG. 4 b;
FIG. 4 b is a detailed view of a knitted article with a fourth fastener type;
FIG. 4 c is a view showing a cross-section through the closed knitted article of FIG. 4 b;
FIG. 5 a is a view showing the section along the line A—A through the knitted article of FIG. 5 b;
FIG. 5 b is a view showing a detailed view of a knitted article with a fifth fastener type;
FIG. 5 c is a view showing a section through the closed knitted article of FIG. 5 b;
FIG. 6 is a view showing a stitch course for producing a fastener element in accordance with FIGS. 1 and 2;
FIG. 7 is a view showing a stitch course for producing a loop-shaped fastener element in accordance with FIGS. 2, 4 , 5 ; and
FIG. 8 is a view a showing a loop course for producing a sleeve-shaped fastener element in accordance with FIGS. 3 and 4.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 b shows a detailed view of a jacket 1 with a button strip 10 and a button hole strip 11 . Instead of the subsequently sewn buttons, button-shaped stitch structures 12 are knitted on the button strip 10 , which together with a round shaped button hole 13 form a fastener of the knitted article 1 . The spacial contour of the button-shaped stitch structure 12 is recognizeable in particular from the sectional views of FIGS. 1 a and 1 c.
FIG. 2 shows the same fastener element 12 which cooperates here however with a loop-shaped fastener element 14 . The edges of the knitted article 2 are not located here over one another as in the knitted article of FIG. 1, but instead are located near one another when the fasteners 12 , 14 are connected (FIG. 2 c ). It is however also possible with this fastener technique to form overlapping knitted article edges.
FIG. 3 shows a knitted article 3 in form of a vest which has a button strip 30 and a button hole strip 31 . Slot-shaped button holes which extend in a longitudinal direction are formed in the button hole strips 31 by a known intarsia technique. Fastener elements 32 in form of a sleeve for a solid body 34 (FIGS. 3 a, 3 c ) are knitted on the button strip 30 . The solid body 34 can be inserted subsequently into the knitted sleeve 32 and then the sleeve 32 is closed by a knot thread 35 (FIG. 3 a ). FIG. 4 shows a knitted article 4 in which the sleeve-shaped fastener element 32 cooperates with a loop-shaped fastener element 36 .
A further alternative of a fastening is shown in the knitted article 5 in FIG. 5 . Both fastener elements 50 , 51 are composed of loop-shaped stitch structures. The stitch structure 50 is shorter and therefore wider, and serves for receiving a tongue 52 . The second loop 51 is thinner and longer, and is located for fastening of the knitted article 5 over the tongue 52 .
All fastening types shown in FIGS. 1-5 can be produced completely or at least substantially on the knitting machine, so that the required subsequent clothing works on the knitted article can be reduced to minimum. In accordance with FIGS. 6-8 preferable manufacturing processes for producing the illustrated, new fastening elements are represented.
FIG. 6 shows the production of the fastener element 2 of FIGS. 1 and 2. A start row for the stitch structure 12 is formed on the front needle bed V through four needles, in row 1 in the knitting direction from right to left with a first knitting system S 1 . The connection for the rear needle bed H is produced by tuck loops on the opposite needles. In row 2 , in knitting direction from left to right, with the first system S 1 and the needles F and H of the front needle bed V stitches are produced, and with the needles D a tuck loop for the stitch structure 12 is produced. The tuck loop on the needle D has no connection to the basic knitted article, whereby the left edge of the fastener element 12 produced by a stitch aggregation is round. Row 3 shows the mirror-symmetrical production of a stitch row in knitting direction from right to left, wherein with the needles E and G stitches are formed and with the needle I a tuck loop is formed for an edge stitch which is not connected with the basic knitting article.
In row 5 a further stitch row follows, whereby only each second needle D, F, H knits, while on the opposite needles E and G tuck loops are produced. In row 5 , in the opposite knitting direction, the production of a further row with alternating stitches and tuck loops is performed, wherein however the needles E, G, and I form stitches and the needles F and H form tuck loops. The rows 4 and 5 are repeated until the stitch structure 12 reaches the desired size. By the alternating knitting of stitches and tuck loops in each knitting row, a voluminous but firm structure is produced. In row 6 , subsequently with the first knitting system S 1 in the knitting direction from left to the right, stitches for the stitch structure 12 are formed on the front needle bed W, and with the needles e and g in the rear needle bed H they are bound in. Subsequently, in the row 7 the hanging of the edge stitches D which are not connected with the basic knitting article to the stitches on the needles e of the rear needle bed H is performed. In row 8 the carriage is moved on that knitting article side, at which the thread guide is located, before in row 9 again a stitch row is knitted on the front needle bed V with simultaneous binding-in in the rear needle bed H. In row 10 then the right edge stitch is hang from the needle I to the stitch on the needle h of the rear needle bed H. After a new empty row 11 , in row 12 a safety knitting row is knitted on the bound-in stitch structure.
FIG. 7 illustrates a possible manufacturing process for a loop-shaped fastener element, such as for example the fastener elements 14 , 36 , 50 , 51 . In row I in the knitting direction from right to left with the first knitting system S 1 , a starting row for the loop-shaped stitch structure is formed on the front needle bed V over four needles. By tuck loops on the opposite needles of the rear needle bed H a connection to the rear needle bed is produced. In row 2 with each second needle F and H, a stitch row for the loop is formed. Subsequently in row 3 in the opposite carriage direction, a further stitch row is formed with each second needle for the loop, whereby however those needle knit which do not knit in the row 2 . The rows 2 and 3 are repeated until the loop reaches the desired length. Subsequently in row 4 the needles of the rear needle bed H are knitted off, before in the row 5 with the first knitting system S 1 the stitches of the rear needle bed H hang on the front needle bed V and thereby the loop is closed.
FIG. 8 illustrates the production of a sleeve-shaped stitch structure for a solid body 34 , as shown in FIGS. 3 and 4. First in row 1 with a first thread guide in a needle region which corresponds to the maximum diameter with the stitch structure 32 , a knot thread is inserted by means of tuck loops into each second needle of the front needle bed V. Then with a second thread guide in row 2 , the formation of a starting row of the stitch structure 32 is performed. This stitch row is bound with tuck loop on the needle G at the left side into the knitted article. In row 3 with the second thread guide, the stitch structure is expanded around two needles to the right. With a tuck loop on the needle M, the binding in of the stitch row into the knitted article at the right side is performed again. In row 4 , in the opposite knitting direction, a further stitch row is formed on the front needle bed V, wherein the stitch structure 32 at the left side is broadened by two stitches and is bound by means of the tuck loop on the needle E into the basic knitted article.
In the rows 5 - 9 the stitch structure is widened to the right in the same way as in row 3 , by one stitch correspondingly. In the knitting rows 6 , 8 and 10 a widening of the stitch structure 32 by one stitch is performed at the left side, in the same way as in the row 4 . Subsequently, in rows 11 and 12 , stitch rows are knitted over the full width of the stitch structure 32 , wherein however the edge needles B and P are not stitched, whereby the edge is rounded. The rows 11 and 12 , depending on desired contour of the stitch structure, are repeated one or many times. In the stitching rows 13 , 15 , 17 and 19 subsequently the stitch structure is reduced at the left side and in the stitching rows 14 , 16 , 18 and 20 is reduced at the left side, until in row 21 a knitting width of two stitches remains. Subsequently, the knot thread is inserted with the thread guide 1 by means of a tuck loop into each second needle of the front needle bed V, so that it is laid U-shaped around the stitch structure 32 . In a subsequent clothing-making step, solid bodies 34 are each inserted in the stitch structure 32 . Subsequently, the both ends of the knot thread 35 at the right end of the stitch structure 32 are contracted and knotted. Thereby a button-like fastener element is produced without a sewing process.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods differing from the types described above.
While the invention has been illustrated and described as embodied in method of producing a knitted article on a flat knitting machine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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A knitting article is produced on a flat knitting machine with at least two needle beds by providing a knitted article with at least one button-shaped knitted stitch structure as a fastener, and converting the structure into several successive rows by knitting with a local stitch aggregation. Also, the stitch structure can be produced by a wedge forming technique with subsequent closing with a knitted-in knot thread. Also, the stitch structure can be formed by knitting with a small knitting strip connected at both ends with the knitted article.
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BACKGROUND OF THE INVENTION
European reference EP-A-0 254 962 discloses an apparatus for the through-contacting and electroplating of printed circuit boards wherein the individual printed circuit boards are continuously conducted through successively arranged treatment baths in horizontal attitude on a horizontal conveying path. The transport of the printed circuit boards through the treatment baths accommodated in treatment cells ensues via horizontally arranged conveyor rollers or via clamps arranged at endlessly circulating drives that seize the lateral edges of the printed circuit boards. In the case of an electroplating treatment, the clamps also simultaneously assume the cathodic contacting of the printed circuit boards. Horizontal slots for the passage of the printed circuit boards are located in the end walls of the treatment cells, whereby roller pairs that are horizontally arranged and that are drive with a speed matched to the speed of the traversing printed circuit boards are allocated to these horizontal slots as seals. The bath liquid emerging from the individual treatment cells is collected in allocated collecting tanks and is continuously returned into the allocated bath cells with the assistance of appropriate pumps. Maintaining a constant level in the individual treatment cells is enabled by the continuous return of the bath liquid.
European reference EP-A-0 421 127 discloses an apparatus for the treatment of printed circuit boards wherein the individual printed circuit boards are continuously conducted through successively arranged treatment baths in a vertically suspended attitude on a horizontal conveying path. The transport of the printed circuit boards through the baths accommodated in treatment cells ensues via clamps arranged at endlessly circulating drives that, in the case of an electroplating treatment, also simultaneously assume the cathodic contacting of the printed circuit boards. Vertical slots for the passage of the printed circuit boards are located and the end walls of the treatment cells, whereby seals fashioned as brush seals or strip brush seals are provided in the passage region. The individual treatment cells are arranged in collecting tanks from which the collected bath liquid is continuously returned into the allocated treatment cells with the assistance of appropriate pumps. Here, too, the continuous return of the bath liquid enables the maintaining of a constant level in the individual treatment cells.
U.S. Pat. No. 4,401,522 discloses a similarly constructed apparatus for the electrolytic treatment of printed circuit boards wherein vertically arranged roller pairs are allocated as seals to the vertical slots in the end walls of the treatment cells. The rollers of these roller pairs composed of elastic material are resiliently pressed against one another and driven with a speed that is matched to the conveying speed of the traversing printed circuit boards.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus for the treatment of printed circuit boards in successively arranged treatment baths wherein a clear increase of the throughput can be achieved with relatively little added outlay. In general terms the present invention is an apparatus for treating printed circuit boards. The conveyor system continuously conducts the printed circuit boards through successively arranged treatment baths in vertical attitude on at least two horizontal conveying paths proceeding next to one another. Treatments cells are arranged successively and next to one another for the acceptance of the treatment baths. The end walls of the treatment cells have vertical slots for the passage of the printed circuit boards. Seals are allocated to the slots. Common collecting tanks are provided for the bath liquid emerging from treatment cells arranged next to one another. Pumps are provided for the continuous return of bath liquid from the collecting tanks into the allocated treatment cells.
In general terms the present invention is also an apparatus for treating printed circuit boards having the above-described conveyor system that continuously conducts the printed circuit boards through successively arranged treatment baths in vertical attitude on at least two horizontal conveying paths proceeding next to one another. Treatment cells are successively arranged for the acceptance of the treatment baths. The end walls of the treatment cells have vertical slots for the passage of the printed circuit boards. Seals are allocated to the slots. Collecting tanks are provided for the bath liquid emerging from treatment. Pumps are provided for the continuous return of bath liquid from the collecting tanks into the allocated treatment cells.
The invention is based on the perception that a treatment of the printed circuit boards in vertical attitude enables a compact, space-saving arrangement with at least two conveying paths that proceed parallel next to one another and at the same level, whereby the employment of common collecting tanks already leads to a substantial reduction of the overall outlay compared to separately constructed individual systems. In one embodiment common collecting tanks are thereby provided for the bath liquid emerging from treatment cells arranged next to one another. In another embodiment, both a common collecting tank as well as a common treatment cell are provided for the treatment zones allocated to the conveying paths and arranged next to one another. A doubling or, respectively, multiplication of the throughout is thus enabled, whereby a common collecting tank, a common heating or cooling, a common level monitoring in the reservoir, a common pump of appropriate capacity and the common employment of further components enable substantial savings for the treatment zones arranged next to one another in the parallel conveying paths. It should also be emphasized that the accessibility of the individual treatment baths, an effective bath monitoring and a simple maintenance of the overall apparatus are fully assured even given a plurality of parallel conveying paths.
What are to be understood in the present invention by the term "printed circuit boards" are not only conventional, bored printed circuit boards but other plate-shaped wirings as well that can also multiply traverse the apparatus under certain conditions for building up a plurality of wiring levels. In addition to the conventional through-contacting and electroplating of printed circuit boards with the corresponding pretreatment and after-treatment steps, an electro-immersion lacquering of the printed circuit boards can also be undertaken, for example, in the inventive apparatus. The layers applied by electro-immersion lacquering can thereby serve as galvano-resist, as etching resist, as solder stop lacquer or also as insulating intermediate layers in the construction of multi-layer wirings. According to the present invention, the printed circuit boards are conducted in vertical attitude through vertical slots in the end walls of the treatment cells, whereby the term "vertical", however, is not intended to mean a limitation to an absolutely vertical alignment. By contrast to apparatus with the prevailing horizontal arrangement, however, the advantages of the invention can likewise be realized with a slightly inclined arrangement of printed circuit boards and slots.
The conveyor means provides a suspended conveying of the printed circuit boards. This enables a suspended conveying of the printed circuit boards that is especially simple to realize.
The conveyor means is fashioned as clamps. This enables a simple and reliable holding of the printed circuit boards by clamps, whereby such clamps are also particularly suited for an automatic charging and removal of the printed circuit boards.
Guides for the printed circuit boards are arranged in the treatment cells. This assures a reliable conveying of the printed circuit boards through the treatment cells in vertical attitude.
The conveyor means of the conveying paths proceeding next to tone another are combined to form a common conveyor device. The common conveyor device is equipped with guide rollers running on guide rails. As a result of the common conveyor means for the conveying paths that proceed next to one another, the improvement of claim 6 enables another substantial reduction of the overall outlay. The employment of guide rails and guide rollers according to claim 7 guarantees a reliable guidance of the conveyor means even given three or more conveying paths.
The conveyor means of the common conveyor device are driven by at least one endlessly circulating drive. The endlessly circulating drive is formed by a chain. This enables a further simplification of the conveying of the printed circuit boards, whereby the employment of an endlessly circulating chain has proven itself as an especially reliable and rugged drive means.
The arrangement has contacting elements for anodic or cathodic contacting of the printed circuit boards and electrodes with the opposite polarity of the contacting elements that are arranged in electrolytic treatment cells. The electrodes are arranged at both sides of the conveying paths of the printed circuit boards. This enables an electrolytic treatment of the printed circuit boards, whereby the arrangement of the electrodes at both sides of the conveying paths assures a high uniformity and effectiveness of this electrolytic treatment.
The contacting elements are formed by the conveyor means and the power supply to the conveyor means ensues with wiper contacting or roller contacting. Thus the electrical contacting of the printed circuit boards given an electrolytic treatment can be undertaken via the conveyor means in an especially simple and reliable way.
At least one cleaning bath for chemical or electrochemical cleaning of the conveyor means is arranged in the region of the returning side of the endless drive. This enables a simple elimination of metal deposits on the conveyor means by chemical or anodic etching.
The return of the bath liquid ensues at least partially via spray pipes arranged in the appertaining treatment cell. The pipes are vertically aligned. The spray pipes are arranged at both sides of the conveying paths of the printed circuit boards. This enables an especially effective treatment of the printed circuit boards by the continuous and targeted delivery of bath liquid to the printed circuit boards. A vertical alignment of the pray pipe has thereby particularly proven itself, whereas an arrangement of the spray pipe at both sides of the conveying paths assures an identical and uniform treatment of both printed circuit board sides.
Means are provided for introducing compressed air into the treatment baths. This enables a further increase in the intensity of the treatment by forming micro-turbulences. Thus, for example, the introduction of compressed air into an electrolytic treatment cell enables higher current densities and, thus, a shortening of the overall length of the apparatus.
The seals are formed by cylinders loosely arranged in pairs in vertical alignment that are pressed against one another or against the respectively passing printed circuit boards by the pressure of a treatment bath. This enables an especially simple and effective sealing of the slots required for the passage of the printed circuit boards. The seals are arranged in sluice chambers attached to the treatment cells at the end side. The loose and vertical alignment of the cylinders employed as seal can be assured in a simple way by the accommodation thereof in sluice chambers.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several Figures of which like reference numerals identify like elements, and in which:
FIG. 1 and FIG. 2 depict a first embodiment of an apparatus for the multi-lane treatment of printed circuit boards in plan view or, respectively, cross-section;
FIG. 3 and FIG. 4 depict a second embodiment of an apparatus for the multi-lane treatment of printed circuit boards in plan view or, respectively, cross-section;
FIG. 5 is a cross-section through an electrolytic treatment module with two treatment cells arranged next to one another;
FIG. 6 depicts the two treatment cells of the treatment module shown in FIG. 5 in a face end plan view or, respectively, cross-section;
FIG. 7 is a cross-section of the conveyor means of the treatment module shown in FIG. 5; and
FIG. 8 is a plan view onto the conveyor means of claim 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In highly simplified schematic fashion, FIGS. 1 and 2 show a first exemplary embodiment of an apparatus for the treatment of printed circuit boards LP that are conducted through successively arranged treatment baths with the assistance of conveyor means T, being guided in vertically suspended attitude on four horizontal conveying paths TW1, TW2, TW3 and TW4 that proceed parallel next to one another and at the same level. In the portion of the apparatus shown in FIG. 1, these successively arranged treatment baths are referenced BB1, BB2 and BB3.
Four treatment cells BZ10, BZ11, BZ12 and BZ13 that are erected in a common collecting tank AW1 and arranged side by side and allocated to the conveying paths are provided for the acceptance of the treatment bath BB1.
Four treatment cells BZ20, BZ21, BZ22 and BZ23 that are erected in a common collecting tank AW2 and arranged side by side and allocated to the conveying paths are provided for the acceptance of the treatment bath BB2.
Four treatment cells BZ30, BZ31, BZ32 and BZ33 that are erected in a common collecting tank AW3 and arranged side by side and allocated to the conveying paths are provided for the acceptance of the treatment bath BB3.
The end walls of all treatment cells are provided with vertical slots S that are dimensioned such that the printed circuit boards LP can be conducted through unimpeded along the conveying paths TW1 through TW4. Sluice chambers SK attached to the treatment cells at the end face accepts seals referenced D that greatly reduce the emergence of bath liquid from the vertical slots S. The seals D are a matter of cylinder loosed arranged in pairs in vertical alignment that are pressed against one another are against the respectively passing printed circuit board by the pressure of the bath liquid. The end walls and the common collecting tanks AW1 through AW3 are provided with vertical slots for the passage of the printed circuit boards, just like the end walls of the treatment cells.
The bath liquid emerging from the individual treatment cells in the region of the slots S or overflowing from the treatment cells is collected in the allocated, common collecting tanks AW1, W2 or AW3. It can be seen from the cross-section through the four treatment cells BZ20 through BZ23 and their common collecting tank AW2 shown in FIG. 2 that the collected bath liquid is continuously returned into the allocated treatment cells BZ20 through BZ23 with the assistance of a common pump P, whereby this return is indicate by arrows Pf. A constant level of the bath liquid can be maintained in the treatment cells BZ20 through BZ23 in this way.
It can also be seen from the cross-section shown in FIG. 2 that the four conveyor means T fashioned as clamps are part of a common conveyor device TE1. The conveyor means T are thereby secured at a distance from the allocated conveying paths TW1 through TW4 (see FIG. 1) at common holders H that are in turn guided via guide rollers FR1 on round guide rails FS1 proceeding at both sides. The drive of the entire conveyor device TE1 ensues via chains K that are coupled to the holders H at both sides and respectively endlessly circulate. The common conveyor device TE1 also offers the possibility of an anodic or cathodic contacting of the printed circuit boards LP above electrolytic treatment cells. This possibility of contacting, however, shall only be discussed in greater detail in conjunction with the conveyor device TE2 shown in FIGS. 7 and 8.
In a highly simplified schematic illustration, FIGS. 3 and 4 show a second exemplary embodiment of an apparatus for the treatment of printed circuit boards LP that, as in the first exemplary embodiment, are again conducted through successively arranged treatment baths in vertically suspended attitude with the assistance of conveyor means T on four conveying paths TW1, TW2, TW3 and TW4 that proceed parallel next to one another and at the same level. In view of the largely identical structure of the exemplary embodiments shown in FIGS. 1 and 2 or, respectively, FIGS. 3 and 4 and of the employment of the same reference characters for identical parts and baths, it is particularly the differences between the two exemplary embodiments that shall be discussed below.
In the second exemplary embodiment shown in FIGS. 3 and 4, respectively common treatment cells that are referenced BZ1, BZ2 and BZ3 in the portion of the overall apparatus shown in FIG. 3 are provided instead of four individual treatment cells arranged next to one another for the accommodation of the treatment baths BB1 through BB3.
The accommodation of the treatment bath BB1 thus ensues in the common treatment cell BZ1 through which the four conveying paths TW1 through TW4 lead. Vertical slots S and sluice chambers SK with seals D are also provided here at the passage locations for the printed circuit boards LP. The common treatment cell is again erected in the common collecting tank AW1.
The following treatment baths BB2 and BB3 are accommodated in the common treatment cells BZ2 and BZ3 in a corresponding way, whereby these common treatment cells BZ2 and BZ3 are erected in the allocated, common collecting tanks AW2 or, respectively, AW3.
According to the cross-section shown in FIG. 4, the return of the bath liquid collected, for example, in the common treatment sic! tank AW2 into the common treatment cell BZ2 ensues at four locations. A common return of the bath liquid or other ways of returning and distributing the bath liquid, however, are likewise possible.
FIG. 5 shows a cross-section through and electroplating treatment module with two electrolytic treatment cells BZ arranged next to one another that are arranged in a common collecting tank AW. The collecting tank AW, which is erected on feet FU and closed at the top with a removable cover hood AH, contains a supply of the electrolytic treatment bath whose level reading is referenced PG. In addition to this function as reservoir, the common collecting tank AW also has the job of accepting the bath liquid emerging from the two treatment cells BZ. A pump P fashioned as immersion pump is arranged within the collecting tank AW for keeping the level constant in the two treatment cells BZ, so that the bath liquid can be continuously returned into the treatment cells BZ in the direction of the arrows Pf via a return conduit RL. For setting the returned amount, a control valve RV inserted into the return conduit RL is located outside the collecting tank AW next to the drive motor AM of the pump P.
FIG. 6 is additionally referenced for further explanation of the two electrolytic treatment cells BZ arranged in the collecting tank AW. It can be seen at the treatment cell BZ shown at the left in FIG. 6 that their end faces have slots S for the passage of the printed circuit boards LP. Further details of these slots S and of the allocated sluice chambers SK and seals D were already discussed in conjunction with FIG. 1. A first distribution chamber VK1 into which a part of the bath liquid conveyed back by the pump P discharges via a first distribution pipe VR1 is formed in the lower region of the treatment cells BZ by a false floor ZB. At its underside, this first distribution pipe VR1 is provided with holes arranged spaced from one another through which the bath liquid emerges, as indicated in FIG. 6 by the arrows Pf. In a similar way, two rows of bores BO1 arranged spaced from one another are located in the false floor ZB, the bath liquid being conducted from the first distribution chamber VK1 vertically upward through these bores BO1 into the actual electroplating zone.
A second distribution chamber VK2 is arranged inside the first distribution chamber VK1 suspended at the false floor ZB, the other part of the bath liquid conveyed back by the pump P being introduced into this second distribution chamber VK2 via a second distribution pipe VR2. The bath liquid then proceeds from this second distribution chamber VK2 into spray pipes SR that are secured residing vertically in the false floor ZB at both sides of the conveying path of the printed circuit boards LP. At their insides, the spray pipes SR arranged in two rows comprise a plurality of spray nozzles not shown in detail in the drawing via which the traversing printed circuit boards LP are directly charged with fresh bath liquid.
A third distribution chamber VK3 into which compressed air is introduced is arranged inside the second distribution chamber VK2 suspended at the false floor ZB. The compressed air indicated by arrows DL then proceeds into the electroplating zone via two rows of bores BO2 introduced into the false floor ZB. A guide F for the printed circuit boards LP that is introduced into the false floor ZB as a U-shaped channel is situated between the two rows of these bores BO2.
Electrodes E that extend along the sidewalls in conveying direction are located inside the electrolytic treatment cells BZ arranged above the false floor ZB at both sides of the conveying path. In the illustrated electrolytic treatment module, these electrodes are anodes that, for example, are composed of titanium baskets and copper balls accommodated therein in the case of an electrodeposition of copper.
It can also be seen from the cross-section shown in FIG. 6 that the two sidewalls of the treatment cells BZ are provided with bevels that are not referenced in detail. As a result thereof, the upper edge of the sidewalls form a defined free-overfall weir over which the bath liquid conveyed back into the treatment cells constantly flows.
The transport of the printed circuit boards LP on two conveying paths proceeding spaced from one another perpendicular to the plane of the drawing ensues via a common conveyor device TE2, FIGS. 7 and 8 being additionally referenced for their further explanation. Two conveyor means T that are again fashioned as clamps are secured to carrier in the spacing of the conveying paths leading through the two treatment cells BZ, these carriers TR being in turn attached to common holders H that extend transversely relative to the conveying direction. Guide rails FS1 and FS2 as well as guide rollers FR1 and FR2 are provided for the guidance of the individual conveyor carriages sic! that are respectively formed of a holder H, two carriers TR and respectively ten conveyor means T arranged at these carriers TR. The round guide rail FS1 extending at the inside of the entire apparatus is secured to the collecting tank AW via angles WI in the region of the illustrated electrolytic treatment module, whereas the second guide rail FS2 having a rectangular cross-section proceeds in the region between the two treatment cells BZ. A conveyor carriage is guided on the inner guide rail FS1 with respectively two upper and two lower guide rollers FR1, whereas only a single guide roller FR2 is provided for support on the middle guide rail FS2. An endlessly circulating chain K that extends at the inside parallel to the guide rail FS1 and to whose coupling elements KG the individual holders H are coupled serves the purpose of driving the individual conveyor carriages.
The conveyor device TE2 also assumes the cathodic contacting of the printed circuit boards LP in the region of the illustrated electrolytic treatment module. To this end, the inwardly disposed part of the holders H is fashioned as power pick-up part SA that, for example, is composed of copper and conducts the current that has been picked up via the holder H, the carriers TR and the conveyor means T to the printed circuit boards LP suspended thereat. For improving the current conduction, the holder H is composed of a copper rod clad with stainless steel. The supply of current ensues via an upper live rail OS that is composed of a copper rod clad with titanium and that is secured to the collecting tank AW via a rail mount SH. A glide rail that, for example, is composed of graphite and that is resiliently pressed via spring elements FE against the power pick-up parts SA wiping thereon proceeds under the upper live rail OS. Copper cables KK are provided for the electrical bridging of the spring elements FE.
In addition to the desired metal deposition onto the traversing printed circuit boards LP, an undesired metal deposition onto the conveyor means T fashioned as clamps also ensues in the electrolytic treatment cells BZ. For eliminating these undesired metal depositions, two cleaning baths RB through which the lower region of the conveyor means T are conducted are arranged under the cover hood AH in the region of the returning side of the conveyor device TE2. The demetallization ensues by anodic etching, i.e. the conveyor means T are anodically contacted in this returning region. Otherwise, the power supply ensues in the same way as the above-explained cathodic power supply in the region of the treatment cells BZ. The structure of the cleaning baths RB, which are likewise provided with passage slots, also has a certain similarity to the structure of the treatment cells BZ. The admission of the bath liquid here ensues via admission pipes ZR, whereas outlet pipes AR are provided for the discharge and the return into the collecting tank AW. The pump required for the admission of the bath liquid is not shown in FIG. 5.
An extraction referenced AG is also situated under the above-described cleaning baths RB, this extraction being connected to a central extraction means (not shown) for generating an under-pressure within the collecting tank AW.
The invention is not limited to the particular details of the apparatus depicted and other modifications and applications are contemplated. Certain other changes may be made in the above described apparatus without departing from the true spirit and scope of the invention herein involved. It is intended, therefore, that the subject matter in the above depiction shall be interpreted as illustrative and not in a limiting sense.
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The printed circuit boards (LP) are conducted through treatment baths (BB1 through BB3) in vertical attitude on at least two horizontal conveying paths (TW1 through TW4) proceeding next to one another, these treatment baths being accommodated in treatment cells (BZ10 through BZ13, BZ20 through BZ23, BZ30 through BZ33) that are arranged successively and next to one another. The end walls of the treatment cells are provided with vertical slots (S) and allocated seals (D) for the passage of the printed circuit boards. The bath liquid emerging from treatment cells arranged next to one another is collected in common collecting tanks (AW1 through AW3) and is returned into the treatment cells with the assistance of pumps (P). A common treatment cell for treatment zones lying next to one another can also be provided in a common collecting tank. The conveying of the printed circuit boards on the conveying paths lying next to one another preferably ensues with a common conveyor device. A cost-beneficial doubling or, respectively, multiplication of the printed circuit board throughput derives due to the two-lane or multi-lane treatment.
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This is a division of application Ser. No. 08/814,093 filed Mar. 10, 1997, now U.S. Pat. No. 5,826,334.
CROSS-REFERENCES
None.
FIELD OF THE INVENTION
This invention relates generally to tube-type boilers, and particularly concerns both a method and apparatus that may be advantageously utilized in connection with the removal of a boiler tube or tubes from installation in a boiler as f or subsequent replacement.
BACKGROUND OF THE INVENTION
Heretofore it has been common practice in connection with the removal of water tubes or fire tubes from within a steam boiler for subsequent replacement to first cut the installed tubes adjacent their header-mounted ends with a cutting torch, to next remove the cut tube lengths, and afterwards forcefully drive the severed tube ends out of engagement with the boiler headers. Such conventional practice is time consuming, expensive to accomplish, and frequently results in damage to the tube mounting bores provided in the boiler headers. Each damaged tube mounting bore in a tube header must be repaired by welding, re-drilling, and honing to proper size for later re-use.
We have discovered a novel method and apparatus that may be utilized to effect the removal of boiler-tube ends from their mountings within a boiler header without causing damage to the co-operating header tube mounting bores, thus eliminating the necessity for subsequent header metal repair and header bore re-drilling and honing.
Other advantages and objectives of the invention will become apparent in the course of considering the descriptions, drawings, and claims which follow.
SUMMARY OF THE INVENTION
The apparatus of the present invention is basically comprised of a rigid support structure, a pair of spaced-apart hydraulic clamping cylinders carried by the support structure and clamped to the interior surfaces of two installed boiler tube ends adjacent the boiler tube end to be removed, and a centrally-positioned and hydraulically actuated tube end slitting tool also carried by the support structure but co-operating with the boiler tube end to be removed. Also comprising the slitting tool is an electric stepper motor mounted on the support structure and linked to spaced-apart tool bit elements included in the slitting tool. The stepper motor functions to radially advance the reciprocating tool bits through the wall thickness of the boiler tube to be replaced. Further, the apparatus includes a source of pressurized hydraulic fluid, a suitable electrical energy supply, and a selectively operated controller that co-ordinates the reciprocating movement of the hydraulically-actuated slitting tool and the radial advancement of the apparatus tool bits by the system stepper motor.
From a method standpoint, the invention involves the conventional initial step of cutting the boiler tube that is to be replaced adjacent the header tube mounting bores in which the tube is installed, and such is followed by the removal of the cut length of boiler tube. Subsequently the boiler tube ends retained in the boiler headers are removed using the properly clamped invention apparatus to machine a longitudinal gap or slot having a depth corresponding to the thickness of the wall of the retained tube end throughout the tube end length, which length is generally somewhat greater than the thickness of the boiler header plate retaining the tube end. After the gap metal has been removed from the tube end wall throughout its length, the tube end is compressed to close the machined gap and then withdrawn in its compressed condition from co-operation with the boiler header tube mounting bore. Such method steps are readily accomplished without causing any damage to the metal of the tube mounting bore in the boiler header and are less time-consuming and costly to achieve than are conventional boiler tube removal methods.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic elevation view of a preferred embodiment of the apparatus assembly of the present invention illustrating its installed relationship relative to a boiler tube end that is to be removed from installation in a boiler header;
FIG. 2 is a top end plan view of the apparatus assembly of FIG. 1;
FIG. 3 is a section view through a clamping cylinder subassembly taken at line 3--3 of FIG. 2;
FIGS. 4 and 5 are section views taken at line 4--4 of FIG. 2 through the apparatus slitter subassembly in two different operating positions;
FIG. 6 is a section view taken at line 6--6 of FIG. 4;
FIG. 7 is a section view taken at line 7--7 of FIG. 4;
FIG. 8 is a section view taken at line 8--8 of FIG. 4; and
FIG. 9 is a view of a gear drive mechanism.
DETAILED DESCRIPTION
A preferred embodiment of the apparatus of the present invention is designated generally as 10 in the drawings and is an assembly basically comprised of rigid support structure 12, a pair of hydraulically-actuated clamp subassemblies 14 and 16 supported by structure 12, and a hydraulically-actuated tube slitter subassembly 18 also supported by structure 12. Although described as being a "tube slitter", subassembly 18 actually functions to form an compression gap throughout the length of the boiler tube end that is to be removed.
Apparatus assembly 10 is illustrated in FIG. 1 as co-operating with the cut-off ends 20 through 26 of boiler tubes previously installed in boiler header 28. Tube end 24 is the tube element part designated for removal from installation within header 28, and its removal typically occurs in connection with subsequent replacement with a new full-length boiler tube.
Support structure 12 of apparatus 10 is basically comprised of a base element 30, a case element 32 which is connected to base element 30 and which houses the principal cutting tool components of subassembly 18, and a support arm element 34 which is connected to case element 32 and which supports the electrically-actuated stepper motor element 36 of subassembly 18. Case element 32 also supports the hydraulic actuator 38 included in subassembly 18 to accomplish powered reciprocable movement of cutting tools installed within case element 32.
The apparatus 10 system also includes sources of pressurized hydraulic fluid and electrical energy (not illustrated), a conventional selectively-operated controller sub-assembly 40 which controls the actuation of subassemblies 14, 16, and 18 through conventional hydraulic control valves 42, and of stepper motor 36.
FIG. 2 details the elongated slots 44 provided in structure base element 30 to permit lateral adjustments to the positions of hydraulic clamp subassemblies 14 and 16 and thereby facilitate their proper alignment for insertion in respective tube ends 20 and 26.
Each clamp subassembly 14 and 16 includes, in addition to disclosed expandable clamping mandrel element 46, a tapered expander element 48 that co-operates with a conical recess in mandrel element 46 and that is connected by a rigid rod 50 to a piston element 52 positioned within a subassembly hydraulic actuator 54. Pressurized hydraulic fluid is flowed into (and from) the interior of hydraulic actuator 54, usually at a fluid pressures of approximately 2,000 psi, through a supply port referenced as 56. When controller 40 operates to open particular control valves 42 to flow pressurized hydraulic fluid to clamping cylinder subassemblies 14 and 16, such flow causes piston element 52, connecting rod element 50, and attached tapered expander element 48 to move upwardly (FIG. 3) and cause the expansion of mandrel element 46 within tube end 20. When the clamping action by subassemblies 14 and 16 is subsequently discontinued and pressurized fluid within actuators 50 is flowed by action of controller 34 and the associated control valve 36 to the hydraulic fluid reservoir provided in apparatus 10, expandable mandrel elements 46 are released from substantial frictional engagement with the interior wall surface of tube ends 20 and 26 through the downward movement of piston 52, rod 50, and expander 48 to permit withdrawal of apparatus 10 from engagement with header 28 and its included tube ends. Spring 57 assists in this downward movement. A tension spring component 58 is connected to base element 30 and to expandable mandrel 46 to maintain the components of subassembly 14 as a unit during insertion/removal in boiler header 28 and during lateral movement in co-operating slot element 44. In one actual embodiment of the invention we preferred that expandable mandrel elements 46 be formed of a dense polyurethane material and that rigid expander element 48 be formed of an aluminum alloy. Alternatively, mandrel 46 can be formed of an aluminum alloy and be partially segmented.
The construction and operation of slitter subassembly 18 included in apparatus 10 is best disclosed by reference to FIGS. 4 and 5 of the drawings. Such subassembly essentially functions in the general manner of a reciprocating, metal-shaving shaper machine tool and includes, in addition to conventional, double-acting hydraulic actuator element 38, a cutting head designated as 60. Cutting head 60 has a generally cylindrical base element 62 that is both slidably contained within structural case 32 and rigidly connected at one end to the actuator rod component 64 of hydraulic actuator 38 by co-operating retainer fitting 66. FIG. 4 illustrates the position of cutting head 60 when rod component 64 of hydraulic actuator 38 is fully retracted. FIG. 5 illustrates the position of cutting head 60 when rod 64 is fully extended. Also, FIGS. 4 and 5 respectively illustrate a subassembly tool holder 68 in its extreme retracted and projected positions before commencing and after completing the cutting of a compression gap in tube end 24.
Cutting head 60 also includes a generally tubular drawbar sleeve element 70 that is rigidly secured to the end of base element 62 opposite retainer fitting 66. Drawbar sleeve 70 has an upper surface opening 72 through which toolholder 68 and its included pair of cutting tool bits 74 and 76 (see FIG. 8) may be advanced into or withdrawn from contact with wall-thickness metal of tube end 24. Toolholder 68 has an inclined under surface 78 that co-operates with the inclined ramp surface 80 of height-adjustment wedge 82 for vertical support, and a contact face 83 that engages an aft face of opening 72 in drawbar sleeve 70. When actuator rod 64 is retracted during a metal-removal stroke, the force required to consequently move engaged cutting tool bits 74 and 76 along their metal-cutting path is transmitted to the tool bits from rod 64 and through retainer fitting 66, slitter head base element 62, attached drawbar sleeve 70, co-operating toolholder face 84, and toolholder 68.
The advancement and retraction of the radial position of toolholder 68 (and included cutting tool bits 74 and 76) within tube end 24 is controlled by actuation of stepper motor 36 and its connected drive train. Such drive drain includes, in part and in addition to height-adjustment wedge 82 which has support wheels 84 and an integral hook 86, an internally-threaded thimble 88 having an integral hook element 90 that engages the integral hook element 86 of wheeled wedge element 82, and an adjustment shaft 92 that is rotatably supported within base element 62 and that has a threaded end 94 that co-operates with the internal thread of thimble element 88.
Also included in the adjustment drive train that is powered by stepper motor 36 are a toothed sprocket 96, preferably formed integral with the end of adjustment shaft 92 opposite threaded end 94, journaled drive shaft 97 connected to stepper motor 36, a toothed sprocket 98 carried by drive shaft 96, and an endless chain element 100 which connects sprockets 96 and 98. (See FIGS. 6 and 7). Note that three meshing gears 101, 102 and 103 shown in FIG. 9 could be substituted for the sprocket and chain drive unit 96, 98, 100.
Although adjustment shaft 92 can rotate relative to its journal support in base element 62, co-operating threaded thimble 88 is prevented from rotating with it by the rotational restraint of wheeled wedge 82 in a bottom-opening slot 102 provided in the lower face of drawbar sleeve element 70 (see FIG. 8) and the interlocking arrangement of wedge hook 86 and thimble hook 90. Also, structure case section 32 is provided with a bottom-opening slot 104 (see FIG. 6) to facilitate the longitudinal movement of chain 100 as actuator rod 64 is extended and retracted and consequently moves adjustment shaft 92, sprockets 96 and 98, and endless chain 100 with it. Further, it should be noted that the support wheels 84 of wheeled wedge element 82 ride on the inner wall surface of boiler tube end 24 as shown in FIGS. 4 and 5.
FIG. 8 discloses the spaced-apart positioning of tool bits 74 and 76 in their toolholder 68 installation. In one embodiment of our invention we utilize cutting tool bits of approximately one-eighth inch width and with a one-half inch space separating the adjacent tool bits. Thus, the reciprocating toolholder and tool bits, upon completion of the longitudinal cuts, have actually formed a longitudinal gap in the retained boiler tube end that is approximately three-fourths inch wide. Such in effect causes formation of a compression gap in the tube wall that has a larger cross-section than the cross-sectional area of the metal actually removed from the tube end by the cutting action of the tool bits.
Although the toolholder 68 of the preferred embodiment has two radially extending cutter bits 74 and 76, the tube slitter assembly 18 also would function if the toolholder had only one bit. If this were the case the assembly would have to be rotated with respect to a tube to make two parallel slots sequentially.
Boiler tubes to which the present invention has had widest application generally are in the size range of from 2 inches diameter to 4 inches diameter, and with wall thicknesses ranging approximately from 0.095 to 0.180 inches. An operating hydraulic pressure of approximately 2,000 pounds per square inch has proven satisfactory with a cutting head reciprocating frequency of 60 cycles per minute being utilized. (Actuator strokes typically may range to approximately 7-8 inches). Also, the pulsed actuation of the apparatus stepper motor to reposition a 30° inclined ramp surface provided in the apparatus wheeled wedge element has been controlled to move the toolholder and included tool bits radially toward tube end wall metal in increments of 0.006 inches per completed cutting stroke (per cycle).
Summarizing the method steps of the present invention, it is first necessary to conventionally cut each boiler tube to be removed adjacent the boiler headers in which it has been installed and the severed tube length removed. The apparatus of the present invention is located in a manner whereby the tube slitter subassembly 18 is aligned with a tube end of the severed boiler tube and with the apparatus clamp subassemblies 14 and 16 properly inserted in adjacent installed tube ends. Pressurized hydraulic fluid is next ported to the clamp assembly actuators to firmly anchor the invention apparatus in place for forming a compression gap in the wall of the retained tube end using the apparatus tube slitter subassembly 18.
Once the apparatus is firmly anchored, pressurized hydraulic fluid is ported to and from the tube slitter subassembly hydraulic actuator to extend the cutter head and included toolholder and tool bits into the length of the retained tube end. Thereafter, the apparatus stepper motor is actuated to advance the included toolholder and tool bits radially relative to the tube to a desired cutting depth. Subsequently pressurized hydraulic fluid is ported to and from the tube slitter subassembly hydraulic actuator to retract the cutter head and included toolholder and tool bits from the length of the retained tube end to cause two parallel longitudinally extending slots to be formed in the tube wall. Next the apparatus stepper motor is actuated to retract the included toolholder and tool bits radially relative to the tube in preparation for the next cutting cycle. This causes a remaining strip of metal to be defined between the parallel pair of slots which enables the strip to be removed and which when removed together with said slots defines a compression gap.
Subsequently the retained boiler tube end is compressed to substantially close the so-formed compression gap whereby the compressed tube end has a significantly reduced cross-sectional circumference and may be readily withdrawn from retention in the co-operating the boiler header.
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An apparatus is provided for removing the severed end-portions of boiler tubes installed and retained in a boiler header without consequential boiler header metal damage and in a manner whereby a compression gap of uniform width is machined throughout the length and thickness of each retained boiler tube end-portion selected for removal, the machined boiler tube end-portion is subsequently compressed to significantly close the machined compression gap and reduce the tube end cross-sectional circumference, and the compressed tube end is withdrawn longitudinally from engagement with the boiler header tube-mounting bore.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention concerns a method and a system for exchange of information and data between communication networks such as for example mobile telephone communication networks, telephone fixed networks, the internet, pure data networks or other networks for speech-based and/or non-speech-based services.
[0003] 2. Description of the Related Art
[0004] The increasing integration of these networks as well as the various services offered over these networks requires seamless, rapid and secure communication also between these networks. In this connection there is a problem that these networks in general are operated using different standards. This concerns not only the data protocol, but rather also the type of addressing of the receiver, the type of accounting of the services utilized by the user, the type and the format of the data as well as in certain cases further specific parameters which are employed by a particular network, which would cause interference or which cannot be interpreted in other networks.
[0005] Since, as a result of their different histories as well as their different requirements with respect to their bandwidth, speed, type of transmission, etc., a standardization of these networks cannot even come into consideration, there is a need for different possibilities, with which the information exchange is simplified or, in fact, even made possible at all.
[0006] From DE 295 11 856 an example of a system is known, with which an exchange of short information (SMS-messaging) between different mobile communication networks is to be made possible. For this purpose each network is assigned a device, which receives, stores and translates in an information exchange format these short messages from the concerned network and then supplies these to a central information distribution facility, which conveys these messages to the device of a target communication network. There the messages are received, the format is translated to the associated network and it is introduced into the network.
[0007] A disadvantage of such a monolithic and centrally organized system is comprised however therein, that in particular for large transmission rates the central switching system is very complex and unwieldy and it is hardly possible with economical effort to carry out a checking or processing of individual exchanged information for example for purposes of accounting. It is a further disadvantage that in the case of an error in the central switching system the connection between the networks can completely collapse.
[0008] DE 195 39 406 discloses a process for relaying speech associated information in the form of recognition associated data packets of a mobile communication network to a different communication network. Between these networks, there is a central facility for relaying information, which via a number of logical transmission channels is connected with the source mobile communication network, and via respectively one physical transmission channel is connected with multiple target communication networks. Each logical transmission channel is associated with a service, for the operation of which a service center is provided, which is located in one of the target communication networks. By the association of respectively one recognition to one logical transmission channel on the side of the mobile communication network and the fixed connection of such a channel with a logical transmission channel leading to a different target network within the concerned physical transmission channel each data packet should be supplied to the desired target network independent of a network specific receiver address. The central facility however has the same disadvantages, as occur in association with the above discussed messaging system.
[0009] Finally from WO 95/33309 a scalable multimedia network is described, which is based on a distributed structure with various hierarchical bus planes, which intends to make it possible for providers of multimedia services to provide in economical manner or supply to a small number of networks and to stepwise build up the capacity with increasing number of users.
SUMMARY OF THE INVENTION
[0010] The present invention is thus concerned with the task, of providing a process and a system for information and data exchange between communication networks of the above described type, with which it becomes possible, in relatively simple and reliable manner, to transmit large amounts of information including those of different type between a multiplicity of various structured networks.
[0011] This task is solved with a process, which in accordance with claim 1 is characterized by the following steps: receipt of information (data) from at least one source-communication network as well as conversion of the information into a system internal data format; transmitting the converted information to a particular service processing unit and processing the information in a predetermined manner; converting the processed information in a format of a target communication network as well as switching and transmitting the information to the target communication network.
[0012] The task is solved by a system, which in accordance with claim 2 is characterized by the following features: at least one data transmission unit for receiving information (data) from a source communication network as well as for conversion of the information into a system internal data format; at least one first switching unit for transmitting the information received from a data transmission unit to a predetermined service processing unit; as well as at least a second switching unit for transmitting the information received from one of the service processing units to a predetermined data transmission unit for converting the information into a format of the target communication network and for sending the information to the target communication network.
[0013] A particular advantage of this solution is comprised therein, that the system is scalable on the basis of its modular construction, that means, can be stepwise expanded according to the information amount (data volume) to be exchanged, in that additional data transmission units and/or first or as the case may be second switching units and/or service processing units can be added.
[0014] In the case that respectively at least two of the mentioned units are present, there exists the possibility that, in the case of a loss of one of the units their function can be taken over by the other unit(s) and thereby a total disruption of the service is avoided.
[0015] The dependent claims relate to further improvements of the invention.
[0016] The modular construction of the system makes possible according to claim 4 also a decentralized arrangement of the units in geographically different locations, so that for example in the case of regional natural catastrophes or a power outage at one location it does not necessarily follow that the entire system collapses and therewith the exchange of information between the networks is interrupted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Further details, characteristics and advantages of the invention can be seen from the following description of a preferred embodiment on the basis of figures. There is shown:
[0018] [0018]FIG. 1 a schematic representation of such an embodiment in association with multiple networks;
[0019] [0019]FIG. 2 a flow diagram of a first example for a processing and data flow;
[0020] [0020]FIG. 3 a flow diagram of a second example for a process and data flow; and
[0021] [0021]FIGS. 4 a , 4 b flow diagram of a functional sequence of a data transmission unit.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The inventive system 700 is connected with a plurality of communication networks 1 , 2 , 3 as seen in FIG. 1. For example it can be assumed, that the first communication network 1 is a mobile telephone network, the second communication network 2 a fixed network for telephone and fax transmission and the third communication network 3 is the internet. Beyond this additional and different networks can be provided for respective exchange of various types of speech-associated or non speech-associated information, which likewise can be connected with a system 700 .
[0023] Among the information which is not speech associated, this includes, besides e-mails, for example written text messages such as the GSM-specific implemented short message service, also know as SMS (short message service) service, for which for one part standardized and for another part non-standardized encoding system exists, that means, different for each mobile radio network.
[0024] Each communication network is comprised of a plurality of participants 11 , 21 or as the case may be 31 , which communicate with each other in known manner within their network 1 , 2 or as the case may be 3 .
[0025] The communication and the information exchange between participants 11 , 21 , 31 of different communication networks 1 , 2 , 3 occurs via the system 700 . Each communication network 1 , 2 , 3 is for this purpose connected via respectively one device 12 , 22 , 32 (communication channel), which serves for receiving, storing and relaying information between the concerned communication network and the system 700 in both directions (bidirectionality).
[0026] The communication between the devices 12 , 22 , 32 on the one hand and the system 700 on the other hand occurs in a data exchange format determined essentially by the concerned communication network 1 , 2 , 3 via a packet switched data service. For this there can be used connections such as for example native X.25 network, Data-P connection, fixed connections or the internet with the known transmission protocol as well as TCP/IP or frame relay.
[0027] The system is therewith in particular suitable for connection of a large number of differently configured communication networks 1 , 2 , 3 , without having to accept a reduction in performance with respect to data throughput of the information to be switched.
[0028] The system 700 is comprised of a plurality of functional units 3 xx, 4 xx, 5 xx, 6 xx, which are organized and associated modularly and decentralized and respectively satisfy only one particular function. The communication of these functional units with each other and therewith the transmission of the information to be relayed between networks 1 , 2 , 3 occurs via a system internal (as described in greater detail below) data format, which optionally includes native, optionally optimized, packet oriented communication protocols.
[0029] This architecture, in addition, offers the advantage that the system is scalable, that means, that the function units 3 xx, 4 xx, 5 xx, 6 xx, depending upon the required capacity, the data volume to be transmitted and/or a desired redundancy, can be provided multiply and it thereby becomes possible that the system is adapted to the actual requirements.
[0030] The functional units 3 xx, 4 xx, 5 xx, 6 xx can be located in geographically distributed locations. This has the advantage, that the operation of the system is substantially independent from local disturbances and other influence, such as for example in the case of loss of power, data line interruptions as well as disturbances such as fire, water, storm, etc. The communication of the functional units with each other occurs therein via the system internal data format, wherein the same connections can be used, as has been already described above for the communication between the devices 12 , 22 , 32 on the one hand and the system 700 on the other hand.
[0031] In particular the system 700 includes a number of data transmission units (relay units) 310 , 320 , 330 which form on the one hand a uni- or bi-directional protocol based point-to-point connection with an integrated protocol conversion characteristic and preferably make possible the production of transaction records.
[0032] The other side is comprised of the communication network 1 , 2 , 3 , wherein the data transmission units 310 , 320 , 330 are respectively connected via the devices 12 , 22 , 32 for receiving, storing and relaying information with respectively one of the communication networks 1 , 2 , 3 .
[0033] Further, at least one first router 410 is provided, which serves for connecting the data transmission units 310 , 320 , 330 with at least one data transmission unit 510 . For connecting this data transmission unit 510 in the reverse direction with the data transmission units 310 , 320 , 330 the system 700 includes further at least one second router 420 .
[0034] The service processing units 510 respectively include differing services selected by the system operator, which take the form of software modules. The services can respectively correspond with varying data contents, which are supplied by the various communication networks 1 , 2 , 3 and following processing are again transmitted thereby. Examples of such services include the receipt, the predetermined processing and the relaying of short messages (SMS), e-mails and faxes, on-line banking (for example balance inquires), games, stock market information, data bank questions (map direction information), etc.
[0035] The system 700 includes finally also at least one computer unit 610 , which communicates both with a data transmission units 310 , 320 , 330 as well as with the at least one service processing unit 510 .
[0036] On the basis of an example the function of the system 700 will now be described. For this purpose it is assumed that an information (news) is communicated from a participant 11 of a first (source) communication network 1 to a participant 21 of a second (target) communication network 2 .
[0037] The information of the participant 11 is supplied within the first communication network 1 with the data format and data protocol used in this first network for the network associated device 12 . In this device the information is temporarily stored, in certain cases converted to an exchange format and transmitted to the associated data transmission unit 310 of the system 700 .
[0038] The data transmission unit 310 receives the information, checks this for any possible transmission errors and produces in the case of an error-free receipt of information a first transaction record with the content “information A from transmitter number 11 to receiver number 21 at time T with identification C received intact”. This first transaction record is supplied for accounting purposes to the at least one accounting unit 610 . Besides this, the message is converted via the data transmission unit 310 into the system internal data format of the system 700 or as the case may be is appropriately formatted and then transmitted to a first switching unit 410 .
[0039] In the first switching unit 410 a first switching table is stored, wherein each source communication network 1 , 2 , 3 is assigned or associated with one of the service processing units 510 . This assignment is made independently of information, conditions or other parameters, which can be preset by the system operator. These parameters include for example system internal conditions such as a particular load of the system and/or the transmitter and/or target number and/or a transmission time for the information to be relayed.
[0040] The first switching unit 410 transmits following interrogation from the first switching table the information contained in the data transmission unit 310 to the service processing unit 510 indicated in the table. This is carried out in appropriate manner also with the information contained in the other data units 320 , 330 .
[0041] In the selected data units 510 the information is processed and for example checked, whether the transmitting user 11 is registered and whether the appropriate charges can be billed to him. When this checking can be positively concluded, the processing unit 510 produces a second transaction record with a content “transmitter number 11 has requested service D at time T uniquely recognizable by the identification C” and transmits this to the accounting unit 610 . As identification C the identification produced by the concerned data transmission unit 310 with the first transaction record is used. Besides this the accounting unit 510 transmits the information to a second switching unit 420 .
[0042] In the second switching unit 420 respectively one second switching table is stored, in which for each receiver number 11 , 21 , 31 the data transmission unit 310 , 320 , 330 of the target communication network 1 , 2 , 3 assigned at the time is stored, which includes the concerned receiver.
[0043] After receipt of the information from the data transmission unit 510 , in accordance with the switching table receiver number 21 is interrogated and subsequently the information is relayed to the therein indicated data transmission unit 320 of the target communication network 2 .
[0044] The data transmission unit 320 converts the information received from the second switching unit 420 out of the system internal data format into the format of the target communication network 2 and transmits the information then to the device 22 associated with this network. From there the information is subsequently supplied via the network 2 to the receiver 21 .
[0045] Simultaneously the data transmission unit 320 produces in the case of an error-free transmission of information a third transaction record with the content “information A from transmitter number 11 to receiver number 21 at time T with identification C fully transmitted”. This third transaction record is then supplied again to the accounting unit 610 .
[0046] The at least one accounting unit 610 then undertakes on the basis of the three transaction records an appropriate invoicing, that means, produces an invoice and transmits this to the transmitter or receiver or other responsible party for accounting purposes. For this purpose, data with various cost information such as for example fees, etc. is stored in accounting unit 610 , which can be attributed individually selectively, that is, to specific transmitters or receivers or other responsible parties.
[0047] In the following, for explanation the functional sequence, there will be described first two examples of possible process and data flows. Subsequently, an example one of the data transmission units 310 , 320 , 330 (switching model) as well as one of the switching units 410 , 420 will be described in greater detail.
[0048] [0048]FIG. 2 shows the first example for such a sequence. In a first step 100 the data set is protocol-typically received from one of the communication networks 1 , 2 , 3 by the data transmission unit 310 , 320 , 330 , which could be located at different geographic origins, according to the above description, by the system 700 . Then the concerned data transmission unit 310 , 320 , 330 checks whether the data set is free of error in accordance with the protocol. If this is the case, then the data set is converted to the system internal data format and stored.
[0049] For this purpose multiple possible memory locations (memory devices in various geographic locations) are provided, in which a parameter data is stored and can be selected depending upon the instantaneous load and availability of the system. Only then is the receipt of the data set confirmed to the transmitter by transmission of a suitable message. This process sequence has the advantage, that even if the case of a system interruption generally no data sequence can be lost, since this is stored magnetically in the memory units of the system. Subsequently (for example for accounting purposes) the first transaction record is produced and stored in a memory location (generally one of the accounting units 610 ) extracted from the parameter data.
[0050] In a second step 101 the data set present in the system internal data format is then recorded from the memory unit into one of the first switching units 410 . In the switching unit 410 the desired target for the data set, that is, the concerned data processing unit 510 , is determined. For this purpose there is used a table with line information present in the parameter data, as well as information contained in the recorded data set such as for example transmitter, receiver, data content, receipt channel information, etc. After determining the responsible service processing unit 510 the data set is further relayed thereto. Non-transmittable data sets are stored in an error memory and can be further processed in desired manner by the system administrator.
[0051] In a third step 102 the data set is recorded in the determined signal processing unit 510 and there processed in the above described manner in the contained software module. At the same time a second transaction record is produced, which is stored for accounting purposes in a memory location (in general again one of the accounting units 610 ) to be extracted from one of the parameter data. The processed data set is subsequently recorded in the system internal data format, wherein possible memory locations can again be extracted from the parameter data. Further, a third transaction record is produced and again stored as described above.
[0052] In a fourth step 103 the processed data set is then recorded from the storage unit into the second switching unit 420 and, taking into consideration the instantaneous load and availability of the system unit, is relayed to a desired target communication network 1 , 2 , 3 and therewith first transmitted to the appropriate data transmission unit 310 , 320 , 330 . The basis for this transmission is a table with line information, from which the parameter data can be extracted, as well as the information contained in the recorded data set.
[0053] In a fifth step 104 the data set transmitted by the second switching unit 420 is subsequently recorded in the determined or specified data transmission unit 310 , 320 , 330 , converted out of the system internal data format into the data format of the target communication network 1 , 2 , 3 and relayed to this network. After receipt of a receipt confirmation transmitted by the appropriate receiver 11 , 21 , 31 (receipt) the data set is erased from the data transmission unit and then a fourth transaction record is produced and recorded as above, wherein the possible memory locations are again taken from the parameter data. One advantage of this sequence is comprised therein, that the production of duplicate accounting data sets is prevented. Subsequently the sequence can be repeated beginning again with the first step 100 .
[0054] A second example begins with the presumption, that in a data processing unit 510 a software module is implemented, with which data sets can be produced asynchronously depending upon an external occurrence. One such software module can be for example for transmission of stock market information, wherein the external event could be for example the exceeding of a limit threshold. In this case in a first step by the service-processing unit 510 in accordance with FIG. 3, a data set is produced for the concerned user and stored in the system internal data format. Then again a first transaction record is produced and as described above is recorded, whereupon the possible memory location for the data set and the transaction record can again be extracted from a parameter data.
[0055] In a second step 151 the data set is then transmitted from the memory location into one of the second switching units 420 and recorded therein. On the basis of a table with line information stored in the parameter data as well as information contained in the recorded set then the desired target, that is the appropriate data transmission unit 310 , 320 , 330 is determined and the data set is transmitted thereto.
[0056] In a third step 152 the notified data transmission unit 310 , 320 , 330 records the data set, converts this to the system internal data format into the data format of the target communication network 1 , 2 , 3 and transmits this to the target communication network. Following the receipt of a receipt confirmation (receipt of the receiver) transmitted by the target network, the data set is erased from the data transmission unit and then a second transaction record is produced and recorded as described above, wherein the possible recording locations are again extracted from the parameter data. An advantage of this procedural sequence is comprised also herein in that the production of duplicitous accounting data sets is avoided. Subsequently the sequence beginning with step 150 can again be repeated.
[0057] It is true in all cases, that for all transaction records two recording locations (accounting units 610 ) can be provided for simultaneous recording, which could be, for example, physically and geographically separated from each other. This redundant memory is possible due to the assignment of unique identification numbers, with which a double-processing is prevented.
[0058] It is further valid, that the various steps (functional segments) described in the two examples can be carried out in respectively geographically differing locations. The connection between the units 3 xx, 4 xx, 5 xx, 6 xx required for carrying out the steps occurs either via system internal or other, generally available, communication connections.
[0059] If, beyond this, these units can be provided redundantly, there results the advantage, that in the case of loss of some or all units in one geographic location the system can continue to operate without interruption with the other units in the other location.
[0060] As has already been described, the processing capacity of the system can be increased by the parallel operation of multiple identical units and therewith in simple manner the capacity can be adapted (scaled).
[0061] The transmission of information or as the case may be data sets between various communication networks 1 , 2 , 3 is made possible on the one hand by the protocol distribution occurring in the data transmission units 310 , 320 , 330 as well as on the other hand by the use of the system internal individual data formats.
[0062] For achieving the above described manner of operation, programs are implemented in the data transmission units 310 , 320 , 330 (switching modules), which can for example be started multiple times. In order to individualize a started program (“event”) to for example with respect to the determined communication line, definition, etc., there is in accordance with FIG. 4 a , in a step 200 , a parameterization carried out on the basis of a parameter-set, which is indexed by the name of the event, and whereby the above-mentioned parameter data is produced.
[0063] Such a started program connects in accordance with step 200 the data transmission unit 310 , 320 , 330 with a communication channel 12 , 22 , 32 of a communication network 1 , 2 , 3 according to the parameterization. According to step 201 it is then interrogated whether the connection has been established without error and in accordance with the protocol. If this is not the case, then in accordance with step 202 an error sequence, for example, in the form of an entry in a log book, an alarm to a system administrator, etc. is carried out and the connection attempt repeated in accordance with step 200 . When the connection has been established without error, then in accordance with step 203 the connection to the receiver or address (opposite location) 11 , 21 , 31 is produced via the concerned communication network 1 , 2 , 3 .
[0064] Finally it is interrogated in accordance with step 204 whether the circuit or network monitoring time has elapsed. If this is the case, then in accordance with step 205 an appropriate alarm signal is transmitted to the opposite location. If the circuit monitoring time has not expired, then in accordance with step 206 is interrogated, whether a complete data set has been received by the communication channel. If this is the case, then the process sequence is commenced with a first routine 250 . Otherwise in accordance with step 207 it is interrogated, whether a request exists, for transmission of the data set. If this is the case, then the process sequence is carried out with the second routine 260 , otherwise a return to step 205 occurs.
[0065] Following the running-through of the first or second routine 250 ; 260 there is in accordance with the step 208 interrogated, whether the monitoring time for this event has expired. If this is the case, then in accordance with step 209 an appropriate status signal is produced and a monitoring monitor 50 (“watchdog”) is transmitted. Otherwise, in accordance with step 210 a still available computing time of another processor is made available.
[0066] A flow diagram of the first routine 250 , with which the received data set (data framework) is processed, is shown in FIG. 4 b . Following checking of the data for possible errors and plausibility in a step 251 , there is next checked in step 252 whether the received data is such as to be further relayed via the system (useful data), or whether this is a confirmation (receipt) for a previously transmitted set of data. This question can be decided for example on the basis of an attribute of the data set.
[0067] If the received data is useful data, then this is first recorded in accordance with step 253 and translated into the system internal format. Subsequently in accordance with step 254 a receipt confirmation (receipt) is transmitted to the sender of the data set and a first transaction record “data was received” is produced, which for accounting purposes is supplied to the accounting unit 610 . Subsequently the process continues with step 208 .
[0068] If the received data is a receipt confirmation of a receiver 11 ; 21 ; 31 , then in accordance with step 255 essentially a transaction record “data was transmitted” is produced, which again for accounting purposes is provided to the accounting unit 610 . Subsequently the process continues with step 208 .
[0069] If in accordance with the second routine 260 (FIG. 4 a ) the data set is to be transmitted, then this is next translated or converted in accordance with step 261 from the system internal data format into the format of the target communication network 1 , 2 , 3 . Subsequently the data set is transmitted in accordance with step 263 and the monitoring device is started, with which the receipt of a receipt confirmation from the receiver 11 ; 21 ; 31 is awaited, and then the process continues with step 208 .
[0070] In the following the basic manner of operation and functioning of the switching units 410 , 420 is described. For this first certain general principles are discussed.
[0071] Each communication channel 12 , 22 , 32 of the inventive system is assigned a unique name comprised of five letters or numbers. Further, each communication channel is connected with a switching location within the communication network 1 , 2 , 3 assigned to it.
[0072] Each data set transmitted in the system respectively has a unique name selected from the supply of names, which are made available by the switching units 410 , 420 connected with each other decentralized in the system. The name of the data set is comprised of five characters, which are uniquely assigned to the communication channel 12 , 22 , 32 which the transaction originally caused, which provides for example the receipt channel, as well as a supplemental character identification chain, which provides the transaction time (transmission or receiver) with date and clock time to the millisecond. Further, a unique name description is employed, which identifies the (user) data set as such and for example differs from the termination data set, which is provided with a different name identification.
[0073] In this manner, from the name of each data set, there can be extracted the employed communication channel 12 , 22 , 32 as well as the external communication network 1 , 2 , 3 inclusive of a switching location in the communication network used therefore and the transaction date and the transaction time. Therewith for each data set a unique identifability is provided, so that large data banks for determination of this information are unnecessary. Thereby it also becomes possible from the content of the data set to obtain directions (“content-routing including sequencing”) as well as run time measurements and a correct following up of the data sets solely on the basis of the name of the data set. In this manner for example short message centers, which are localized in various GSM-networks, can be connected with each other.
[0074] Finally, therewith it is also possible to have an intelligent load control or as the case may be load distribution to other switch units depending upon the instantaneous load of individual switching units 410 , 420 .
[0075] In more detail, the data sources connected with one switching unit 410 , 420 , which involve the data transmission units 310 , 320 , 330 as well as the data processing units 510 , are cyclically interrogated whether a data set to be transmitted is present. This interrogation can occur according to a fixed priority sequence.
[0076] If such a data set is located, then the relative data for further relaying is extracted therefrom. This includes for example the transmitter number, the target number, used communication channels, in certain cases text content, if the data set is to be propagated depending upon its content, as well as possible other special information. On the basis of this extracted data, the desired target is determined using a switching table. Further it is to be checked, whether the data set contains a sequence request, that is whether the individual data packets must be received by the receiver in a predetermined sequence. This is for example frequently the case for content dependent relaying. If such a sequence request exists, then the data set is relayed to a predetermined communication channel or as the case may be a communication channel group for this purpose.
[0077] Otherwise it is determined, whether another local path to the receiver indicated in the switching table is available and not overloaded. This is determined for example on the basis of a task waiting list, a delivery list as well as by a comparison between a maximal allowable number of tasks. Depending upon this comparison the data set is then either relayed via the local path to the data transmission unit, or it is determined, whether within the system a different path leads to this data transmission unit, which is available and (following carrying out of the mentioned comparison) is not overloaded. If all other paths are not available or are overloaded, then the data set is transmitted to a buffer area and there stored temporarily, in order to be transmitted at a later point in time to the target. A target therein could be either the communication network 1 , 2 , 3 as well as a service operating in the service processing unit 510 .
[0078] For monitoring the system 700 as well as for ensuring an even loading or as the case may be an optimal processing speed one or more monitoring monitors 50 (FIG. 1) are provided, which can be evaluated using status reports. Each running program (event), that is, each of the units 3 xx, 4 xx, 5 xx, 6 xx, produces at predetermined time intervals, which can be selected by the system administrator, those status reports which contain information regarding the circuit availability, traffic statistics and quality information, such as example the number of successful transmissions and the number of negative reported transmissions, as well as indications regarding the instantaneous load condition, that is the number of the instantaneous tasks still waiting in the waiting list. The status reports are magnetically stored as data in predetermined locations, so that the monitoring monitors (or other evaluation programs) are only coupled loosely to the switching units 410 , 420 and by their operation cannot introduce during their operation errors into other program sequences.
[0079] The monitoring monitors 50 asynchronously access the stored status reports and prepare the contained information for evaluation by a system administrator, for example, HTML-based graphics, or transmit these as short reports. This has the advantage, that simultaneously multiple system administrators at different work locations with differing operation systems can work on the system and monitor this. Further, on the basis of limitations (limitation parameters) it can be determined, whether this system or as the case may be individual running programs are reaching a critical condition and for example are no longer active within the predetermined timeframe (“Watch Dog”—process, dead man switch).
[0080] Finally there is the possibility of a remote monitoring of one or more of the monitoring monitors 50 by a supervision software, if this is installed for example on a physically and geographically independent system (separate computer, notebook), which is provided with a mobile telephone as well as a device, via which a monitoring person can independently call up from a remote location using a telephone network. The supervisor software checks in regular time intervals the status reports of the monitoring monitor 50 . If errors occur in such a report, or the exceeding of a threshold value is indicated, or within a predetermined time interval it is not received, then automatically the remote location is dialed up and an appropriate predetermined message is transmitted to the monitoring person.
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The invention relates to a method and a system ( 700 ) for exchanging information between a plurality of communication networks. The system is especially characterised by at least one data transmission unit ( 310, 320, 330 ) for receiving information from at least one source communication network and converting the information into an intra-system data format; at least one first switching unit ( 410 ) for transmitting the information received by a data transmission unit ( 310, 320, 330 ) to a pre-determined service processing unit ( 510 ); in addition to at least one second switching unit ( 420 ) for transmitting the information received by one of the service processing units ( 510 ) to a pre-determined data transmission unit ( 310, 320, 330 ) for converting the information into a format of the target communication network and sending the information to the target communication network.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application Ser. No. 60/148,610 filed Aug. 12, 1999, which is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH & DEVELOPMENT
The U.S. Government has rights in this invention pursuant to Contract No. NSF-9710197 awarded by the National Science Foundation.
BACKGROUND OF THE INVENTION
The present invention generally relates to the preparation of molecular or ionic supramolecular assemblies, and more particularly to the formation of nanometer scale structures, having a substantially enclosed volume.
Encapsulation of one chemical species by another, sometimes termed “host-guest chemistry”, is a phenomenon that has a wide range of applicability. For example, encapsulation technology is presently used to produce pressure-sensitive inks for carbon copies and is of interest for use in drug delivery. Encapsulation could play an important role in modifying the physical properties of drug substances to enhance their compounding properties for oral and topical administration. Encapsulation could also be important for development of nano-devices, where it could provide a way of insulating molecular wires from each other much as the myelin sheath functions on neurons. In view of the importance and variety of context in which encapsulation plays a critical role, it would be desirable to control the volume within which a species is encapsulated by another. It would be particularly desirable to have a way in which to control the volume enclosed by an encapsulating species without changing fundamentally the composition, and therefore the chemical reactivity, of that species.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a way of controlling the volume enclosed by encapsulating species and controlling the topology of that enclosed volume. An encapsulating or “clathrating” species that exists either as a spherical cluster or as a tubule is prepared by varying the proportions of the constituents of the encapsulating species.
More specifically, the inventors have found that variation in the proportion of a co-ligand added to a mixture of a calix[4]arene bearing a potential ligating group in the para-position and a n+ metal ion (where n=2-3) changes the topology of the solid-state structure into which the species assembles. Still more specifically, the applicants have found pyridine-N-oxide to be especially useful as a co-ligand when used in conjunction with p-sulfonatocalix[4]arene complexed to lanthanide(III) species.
Accordingly, in carrying out the present invention, there is provided a composition comprising a calixarene, a co-ligand, and a 2 + or 3 + metal ion in a ratio of about 1:1:1 to about 2:8:1. Preferably the calixarene has the structure
wherein R′, R″, R′″, and R″″ are functional groups capable of binding to a metal ion. More, specifically, R′, R″, and R′″, and R″″ can be the same or different and are independently selected from the group consisting of amino, sulfonate, carboxylate, hydroxamate, phosphonate, and pyridyl groups.
In a further aspect of the invention, the metal ion of the above composition is an element with atomic number Z, which is 12 and/or within the ranges of 20-31, 38-50, and 56-82. In a specific embodiment of the invention, the metal ion is selected from the group consisting of calcium, cadmium, copper, yttrium, and lanthanum. The co-ligand is selected from the group consisting of heterocyclic N-oxides, phenols, anilines, and nitrobenzenes. More specifically, the co-ligand is selected from the group consisting of pyridine N-oxide, quinoline-N-oxide, phenol, aniline, and nitrobenzene.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1 B, and 1 C schematically depicts the reaction of p-sulfonatocalix[4]arene anions with pyridine N-oxide and La(III) (2:2:1 mole ratio) to form a C-shaped dimeric assembly that forms the basic unit of a spherical assembly.
FIG. 2 shows an external and cross-sectional view of a space-filling model of the sphere formed by p-sulfonatocalix[4]arene anions in the presence of pyridine N-oxide and La(III) (2:2:1 mole ratio).
FIG. 3 schematically depicts the self-organization of p-sulfonatocalix[4]arene anions with pyridine N-oxide and La(III) (2:8:1 mole ratio) into structures with tubular morphology.
FIG. 4A shows a partial cross-sectional view of the tubular structure showing the arrangement of p-sulfonatocalix[4]arene anions, pyridine N-oxide, and La(III) (outlined) to form the curved surface that defines the tube, and
FIG. 4B shows the molecular structure of the repeating unit.
DETAILED DESCRIPTION OF THE INVENTION
p-Sulfonatocalix[4]arene is a macrocyclic anion having a truncated pyramid shape and containing a hydrophobic cavity bounded by four aromatic rings. The base and apical square faces of the truncated pyramid are defined by sulfonate groups and phenolic hydroxyl groups respectively, and the trapezoidal faces consist of the external surfaces of the aromatic rings. As used herein, “up” and “down” orientations of the truncated pyramid refer to the position that would be occupied by the apex of the pyramid if it were not truncated. Since the negatively charged sulfonate groups repel each other electrostatically, they form the base of the pyramid, while the hydroxyl groups are directed toward the apex. The p-sulfonatocalix[4]arene shown below is in the “down” orientation.
The bipolar amphiphilic nature of p-sulfonatocalix[4]arene, in conjunction with its truncated pyramidal shape, serves as a dominant structure-directing factor in the organization of this macrocycle in its solid-state structures. For example, in the crystal structure of Na 5 [p-sulfonatocalix[4]arene] (J. L. Atwood, A. W. Coleman, H. Zhang, S. G. Bott, J. Incl. Phenom . 5, 203 (1989)), the hydrophobic cores of the truncated pyramids align to form a bilayered structure consisting of alternating organic and aqueous layers. This structure is consistent with the arrangement of a bipolar amphiphilic molecule according to the influences of hydrophobic effects. The aqueous layers are composed of the polar surfaces of the truncated pyramids, water molecules, and counter ions. The organic layers consist of a π-stacked, two-dimensional bilayered grid composed of truncated pyramids arranged in an alternating “up-down,” antiparallel fashion with their aromatic rings in van der Waals contact with those of adjacent calixarene molecules. This aspect of the structure may be interpreted in terms of organization of the truncated pyramids according to shape complementarity (G. M. Whitesides, J. P. Mathias, C. T. Seto, Science 254, 1312 (1991); A. Terfort, N. Bowden, G. M. Whitesides, Nature 386, 162 (1997)).
Although the bilayer arrangement of p-sulfonatocalix[4]arene persists in many of its structures (see J. L. Atwood et al., J. Am. Chem. Soc . 113, 2760 (1991); J. L. Atwood et al., Inorg. Chem . 31, 603 (1992)), the inventors found that it is possible to influence the relative orientation of the truncated pyramids with respect to each other, and in particular to alter the orientation of the truncated pyramids into an “up-up” arrangement.
Referring to FIGS. 1A, 1 B, and 1 C, addition of 2 moles of pyridine N-oxide to an aqueous solution comprising 2 moles of p-sulfonatocalix[4]arene pentaanion 12 and 1 mole of a lanthanide metal (Ln 3+ ) nitrate yields a framework in which two p-sulfonatocalix[4]arene anions coordinate to a La(III) ion through their sulfonate groups to form C-shaped dimeric assembly 14 . FIG. 1B shows the dimeric assembly 14 which provides linkages between spheres 20 (shown in FIG. 2) which are connected through the linkages 14 (shown in enlarged form in FIG. 1B) to form an assembly 16 of the spheres (as shown in FIG. 1 C). In addition, two pyridine N-oxide ligands, both of which coordinate to the La(III) ion, bind within the respective calixarene cavities of the dimer. In these dimeric assemblies, the Ln 3+ ion acts as a hinge while the steric requirements of the pyridine N-oxide ligands binding concomitantly to the Ln 3+ ion and the calixarene cavities impart a dihedral angle of 60° between the p-sulfonatocalix[4]arene molecules.
This dihedral angle helps p-sulfonatocalix[4]arene to assemble into structures with curved surfaces, such as spherical clusters composed of 12 p-sulfonatocalix[4]arene pentaanions 12 arranged at the vertices of an icosahedron, to form spherical structure 20 based upon icosahedral structure 22 , as shown in FIG. 2 . Each spherical structure 20 measures approximately 28 Å (2.8 nm) in diameter and has a volume of approximately 11,000 Å 3 , depicted in cross-section 24 of spherical structure 20 . As in the bilayer structures observed for Na 5 (p-sulfonatocalix[4]-arene), the hydrophobic regions of the truncated pyramid-shaped anions are aligned, but in this case they are assembled in an “up-up,” radially symmetric fashion along the surface of a sphere, where they constitute an organic shell around an aqueous polar core. Thus, 48 negatively charged sulfonate groups from the larger faces of 12 truncated pyramids lie on the exterior of the sphere and define a polar, outer shell surface. Similarly, a polar, inner shell surface comprises 48 phenolic hydroxyl groups, 12 of which are deprotonated, from the smaller faces of the truncated pyramids. This arrangement is consistent with that often observed in unilamellar vesicles in which the larger polar head groups of bipolar amphiphiles are preferentially oriented toward the external surface of the membrane, while the smaller polar headgroups are oriented toward the interior.
The cavities of the calixarenes in spherical structure 20 lie just below the polar surface of the sphere and constitute a series of hydrophobic pockets. Twelve pyridine N-oxide molecules penetrate the polar surface of each sphere and bind within the hydrophobic pockets through π-stacking interactions, while their oxygen atoms extend outward from the pockets and coordinate to La(III) ions above the sphere surface. The aqueous, interstitial areas between spheres contain, in addition to La(III) ions, an intricate H-bonded network of water molecules and hydrated Na + ions. The core of each spherical structure 20 has a diameter of approximately 15 Å and a volume of approximately 1700 Å 3 and contains a well-defined cluster consisting of 30 water molecules and two Na+ ions.
Referring to FIG. 3 and FIG. 4, addition of 8 moles of pyridine N-oxide to an aqueous solution comprising 2 moles of p-sulfonatocalix[4]arene pentaanion 12 and 1 mole of a lanthanide metal (Ln 3+ ) nitrate yields crystals of tubular structure 32 after several days. Each tubular structure 32 is approximately 28 Å (2.8 nm) in diameter and consists of p-sulfonatocalix[4]arene molecules 12 arranged along the surface of a cylinder. The tubes are aligned with the long axis of the needle-shaped crystals and therefore have lengths approaching 1 cm in some cases. The tubular structure 32 in cross-section view 42 bears a close resemblance to that of cross-section 24 of spherical structure 20 (shown in FIG. 2) and consists of an analogous polar core, an organic shell, and a polar, inner and outer shell surface. As in spherical structure 20 (shown in FIG. 2 ), the sulfonate groups of the truncated pyramid-shaped calixarenes comprise a polar outer surface while the hydroxyl groups define a polar, inner shell surface. In tubular structure 32 , however, the organic shell is no longer composed purely of calixarene molecules but now contains two crystallographically unique pyridine N-oxide molecules 34 intercalated between the aromatic rings of adjacent calixarenes. One type of pyridine N-oxide 34 is disordered and is oriented such that its oxygen atom is directed toward the interior of the tube. The other type is oriented such that its oxygen atom is directed toward the outer polar surface of the tube where it coordinates to Na+ ions in insert 44 . In addition, each pyridine N-oxide molecule participates in π-stacking interactions (both T-shaped and parallel-offset types) with the aromatic rings of four surrounding calixarene molecules.
Another notable feature of tubular structure 32 is that the p-sulfonatocalix[4]arene pentaanion 12 and the intercalated pyridine N-oxide molecules form a chiral, helical assembly along the length of the tube. The helix consists of a single strand of alternating p-sulfonatocalix[4]-arene pentaanions 12 and pyridine N-oxide molecules, and there are 4.5 of these units in each turn. These tubular assemblies are arranged in a hexagonal array in a pattern similar to the organization of cylindrical micelles. The Na+ ions assist in stabilizing the tubular assemblies by coordinating to the sulfonate groups of calixarenes in adjacent turns of the helix. In this structure, there are two types of pyridine N-oxide molecules that fill the calixarene cavities. One type of pyridine N-oxide is bound within the calixarenes of C-shaped dimeric assembly 14 , and is coordinated to La(III) ions that, in turn, join adjacent tubes. The second type of pyridine N-oxide is disordered and its oxygen atom extends into a triangular-shaped tunnel lined by the outer surfaces of three adjoining tubes. These tunnels, which contain a disordered network of water molecules and Na+ ions, are created by the hexagonal packing arrangement of the tubes. Here too C-shaped dimeric assemblies 14 persist but the dihedral angle between the calixarene molecules is only about 15°. In proceeding from the sphere to the tube, the aqueous core has become a cylindrical channel with a diameter of 15 Å. This channel, which is not well resolved because of disorder, now contains La(III) ions in addition to the hydrated Na+ ions observed in the spherical core.
The intercalation of pyridine N-oxide into the organic shell has an effect equivalent to increasing the hydrophobic volume of the structural components that make up the shell, but contributing little to their polarity. According to the concept of critical packing parameters, an increase in the volume of the hydrophobic portion of a given amphiphile favors the formation of a cylindrical rather than a spherical structure. This model offers at least a qualitative explanation for the transition from the spherical morphology of spherical structure 20 to the tubular morphology of tubular structure 32 .
The generality of this design strategy was explored with respect to a number of factors. Spherical structures analogous to spherical structure 20 are obtained with other lanthanide ions including Pr, Nd, Eu, Gd, Tb, Dy, Er, and Yb. In the case of the tubular structure 32 it was possible to obtain an analogous tubular structure for Gd and Yb. Although there are slight differences in unit cell dimensions and in some minor features of the structures, the spherical and tubular calixarene assemblies are essentially identical throughout the series. Therefore, it appears that variations in the size of the lanthanide ions are absorbed by subtle changes in intermolecular bond distances and angles in the surrounding interstitial areas, but the geometry of the spheres and tubes is conserved.
The instant compounds find use as a way of encapsulating drugs including, but not limited to, the antihistamine fexofenadine hydrochloride ((±)-4-[1-hydroxy-4-[4-(hydroxydiphenyl-methyl)-1-piperidinyl]butyl]-α,α-dimethyl benzeneacetic acid hydrochloride, sold in the US as Allegra™), loratadine (4-(8-chloro-5,6-dihydro-11H-benzo-[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylic acid ethyl ester, sold in the US as Claritin™), buproprin 1-(3-chlorophenyl)-2-[(1,1-dimethyl-ethyl)amino]-1-propanone hydrochloride, sold in the US as Wellbutrin™, divalproex sodium, a compound of sodium valproate (sodium 2-propylpentanoate) and the parent acid, sold in the US as Depakote™, and gabapentin (1-[aminomethyl]-cyclohexane-acetic acid, sold in the U.S. as Neurontin™).
This work has been described in detail (Orr, G. W.; Barbour, L. J.; Atwood, J. L.; Science vol. 285, p. 1049-1052 (1999)), the disclosure of which is incorporated by reference in its entirety.
EXAMPLE 1
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and La(NO 3 ) 3 .6H 2 O (1.15 M) were combined in a 2:2:1 molar ratio. After about 1 hour, crystals formed that were suitable for single-crystal X-ray diffraction analysis. The spherical assembly crystallizes in the trigonal system, space group R3 (no.148), a=b=44.553(4) Å, c=35.223(4) Å, V=60549(10) Å 3 , z=18, ρ calc =1.300 g cm −3 , λ(Mo Kα)=0.70930 A. The crystal structure reveals a framework in which two p-sulfonatocalix[4]arene anions coordinate to a La(III) ion through their sulfonate groups to form a C-shaped dimeric assembly, as shown in FIG. 1 B. In addition, two pyridine N-oxide ligands, both of which coordinate to the La(III) ion, are bound within the respective calixarene cavities of the dimer. In these dimeric assemblies, the Ln 3+ ion acts as a hinge while the steric requirements of the pyridine N-oxide ligands binding concomitantly to the Ln 3+ ion and the calixarene cavities, imparts a dihedral angle of 60° between the p-sulfonatocalix[4]arene molecules.
EXAMPLE 2
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine-N-oxide (3.07 M), and La(NO 3 ) 3 .6H 2 O (1.15 M) were combined in a 2:8:1 molar ratio and deposited needle-shaped crystals after approximately one hour. The tubular assembly crystallizes in the trigonal system, space group P3 1 12 (no.151), a=b=30.4533(11) Å, c=16.2800(8) Å, V=13075.4(9) Å 3 , z=3, ρ calc =1.733 g cm 3 , λ (Mo Kα)=0.70930 A. Crystallographic analysis of these crystals revealed a tubular assembly (4), approximately 28 {haeck over (A)} (2.8 nm) in diameter and consisting of p-sulfonatocalix[4]arene molecules arranged along the surface of a cylinder. The tubes were aligned with the long axis of the needle-shaped crystals and have lengths approaching I cm in some cases.
EXAMPLE 3
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Cd(NO 3 ) 2 (1.20 M) were combined in a 2:2:1 molar ratio. After about 1 hour, crystals formed that were suitable for single-crystal X-ray diffraction analysis. The spherical assembly crystallizes in the trigonal system, space group R3 (no.148), a=b=45.082(2) Å, c=30.814(2) Å, z=18. The crystal structure was not refined, but a spherical structure could be seen in the preliminary x-ray structure.
EXAMPLE 4
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Cd(NO 3 ) 2 (1.20 M) were combined in a 1:1:1 molar ratio. After about 1 hour, crystals formed that were suitable for single-crystal X-ray diffraction analysis. The spherical assembly crystallizes in the trigonal system, space group R3 (no.148), a=b=45.082(2) Å, c=30.814(2) A, z=18.
EXAMPLE 5
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Ca(NO 3 ) 2 (1.05 M) are combined in a 2:2:1 molar ratio. An aqueous solution of gabapentin (1.00 M) is added to the 2:2:1 aqueous solution such that the ratio of components is 2:2:1:0.167, where the 0.167 is the gabapentin. The spherical assembly is then crystallized with the gabapentin encapsulated in the sphere. The drug-containing compound is characterized by X-ray diffraction, solid state NMR, IR, and electrospray mass spectrometry. The encapsulated gabapentin is administered as an oral formulation that has improved sustained release properties.
EXAMPLE 6
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Ca(NO 3 ) 2 (1.05 M) are combined in a 2:8:1 molar ratio. An aqueous solution of gabapentin (1.00 M) is added to the 2:8:1 aqueous solution such that the ratio of components is 2:8:1:0.167, where the 0.167 is the gabapentin. The mixture is then crystallized with the gabapentin encapsulated in the tubule structure. The drug-containing compound is characterized by X-ray diffraction, solid state NMR, IR, and electrospray mass spectrometry.
EXAMPLE 7
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Ca(NO 3 ) 2 (1.05 M) are combined in a 2:2:1 molar ratio. An aqueous solution of fexofenadine hydrochloride (1.00 M) is added to the 2:2:1 aqueous solution such that the ratio of components is 2:2:1:0.167, where the 0.167 is the fexofenadine hydrochloride. The spherical assembly is then crystallized with the fexofenadine encapsulated in the sphere. The drug-containing compound is characterized by X-ray diffraction, solid state NMR, IR, and electrospray mass spectrometry.
EXAMPLE 8
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Ca(NO 3 ) 2 (1.05 M) are combined in a 2:8:1 molar ratio. An aqueous solution of fexofenadine hydrochloride (1.00 M) is added to the 2:8:1 aqueous solution such that the ratio of components is 2:8:1:0.167, where the 0.167 is the fexofenadine hydrochloride. The mixture is then crystallized with the fexofenadine contained in the tubule structure. The drug-containing compound is characterized by X-ray diffraction, solid state NMR, IR, and electrospray mass spectrometry.
EXAMPLE 9
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), pyridine N-oxide (3.07 M), and Y(NO 3 ) 3 .6H 2 O (1.15 M) are combined in a 2:8:1 molar ratio. An aqueous solution of Ba(NO 3 ) 2 and Cu(NO 3 ) 2 in a 2:3 mole ratio (2.10 M and 3.15 M, respectively) is added to the 2:8:1 molar ratio solution such that the ratio of components is 2:8:1:2:3. The mixture is then crystallized with the Y, Ba, and Cu contained in the tubule structure. The compound is characterized by X-ray diffraction, solid state NMR, IR, and electrospray mass spectrometry.
EXAMPLE 10
Aqueous solutions of Na 5 (p-sulfonatocalix[4]arene) (0.283 M), 2 (3.07 M), and Ca(NO 3 ) 2 (1.05 M) are combined in a 2:2:1 molar ratio. A solution of sodium valproate in acetone (1.00 M) is added to the 2:2:1 aqueous solution such that the ratio of components is 2:2:1:0.167, where the 0.167 is the sodium valproate. The spherical assembly is then crystallized with the sodium valproate encapsulated in the sphere. The drug-containing compound is characterized by X-ray diffraction, solid state NMR, IR, and electrospray mass spectrometry. The encapsulated sodium valproate is administered in an oral formulation. The drug-containing compound has improved handling properties because it is less hygroscopic and it has improved sustained release properties.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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Amphiphilic, polyhedron-shaped p-sulfonatocalix[4]arene building blocks, which have been shown previously to assemble into bilayers in an antiparallel fashion, assemble in a parallel alignment into spherical and helical tubular structures on the addition of pyridine N-oxide and lanthanide ions. The addition of greater amounts of pyridine N-oxide changed the curvature of the assembling surface and led to the formation of extended tubules. The inventive compositions and methods are useful for drug delivery and construction of nano-devices.
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FIELD OF INVENTION
[0001] This invention relates to growth of compound nanomaterials and thin films using ultrafast pulsed laser ablation and deposition.
BACKGROUND OF THE INVENTION
[0002] Nanomaterials have important potential applications in modern technologies. Depending on the number of spatial dimensions on which the material expands beyond the nanoscale, nanomaterial can be classified as zero-dimensional (nanoparticles), one-dimensional (nanorods and nanowires), and two-dimensional (nanosheets and nanometer thin films). For each of these categories of nanomaterials, the synthesis methods are different. For example, nanoparticles are often produced using the sol-gel process; nanorods are often produced using the vapor-liquid-solid (VLS) process [S. Wagner and W. C. Ellis, Applied Physics Letters, Vol. 4 (1964), 89; A. M. Morales and C. M. Lieber, Science, Vol. 279 (1998), 208; W. Lu, C. M. Lieber, Journal of Physics D: Applied Physics, Vol 39 (2006), R387, S. C. Tjong ed., Nanocrystalline Materials, Elsevier, Amsterdam, 2006, pp 95 and U.S. Pat. No. 5,897,954, U.S. Pat. No. 6,036,774, U.S. Pat. No. 6,225,198], which involves pre-deposited metal (such as gold) particles as a catalyst to induce nanorod growth; and nanometer thin films are often grown by epitaxy methods such as molecular beam epitaxy (MBE) and chemical vapor deposition (CVD). Regarding the VLS method that is commonly used for growth of nanorods and nanowires, because the pre-deposited metal catalyst can bring in an undesirable impurity for many applications (for example, gold is detrimental to silicon devices), many attempts have been tried to develop non-catalytic or self-catalytic (i.e., using the same material intended for growth as the catalyst) growth methods. Examples are U.S. Pat. No. 6,225,198, U.S. Pat. No. 6,720,240, and W. I. Park et al., Applied Physics Letters, Vol 80 (2002), 4232, L. C. Chen et al., Journal of Physics and Chemistry of Solids, Vol 62 (2001), 1567.
[0003] On the other hand, for material growth, regardless of the intended final morphological forms, a means of producing gaseous or liquid phase source material is always needed. Among the various methods of producing gaseous source materials (e.g., thermal evaporation or using chemical precursors), pulsed laser ablation (PLA) is a relatively new method. In this technique, a pulsed laser beam is focused on to a target surface to ablate materials. Typical lasers used for ablation include Q-switched Nd:YAG and excimer lasers, which can provide pulses with a pulse energy of a few hundreds of mJ and a pulse duration of a few nanoseconds. Because of the short pulse duration, the peak power is very high. Under such intense laser irradiation, the target surface material is inevitably evaporated. The resultant vapor is often ionized, appearing bright, and is thus called plume. The vapor can then be deposited onto a substrate to form new forms of materials. This constitutes the basics of the technique of pulsed laser deposition (PLD). FIG. 1 illustrates the PLD setup used in the current invention.
[0004] The most widely pursued morphological form of the deposited material using PLD is two-dimensional thin film. Nanoparticles have also been generated by supplying a background gas with a high pressure (a few Torr) during ablation to force particle nucleation in the laser-induced vapor [T. G. Dietz et al., J. Chem. Phys. 74, 6511 (1981), T. Seto et al., Nano. Lett. 1, 315 (2001), M. Hirasawa et al., Appl. Phys. Lett. 88, 093119 (2006)]. The particles can then be carried by a carrier gas to a substrate. Using metal particles as catalysts and PLA as the evaporation source, semiconductor nanorods have been produced in an essentially VLS (vapor-liquid-solid) fashion [A. M. Morales and C. M. Lieber, Science, Vol. 279 (1998), 208; W. Lu, C. M. Lieber, Journal of Physics D: Applied Physics, Vol 39 (2006), R387; S. C. Tjong ed., Nanocrystalline Materials, Elsevier, Amsterdam, 2006, pp 97].
[0005] Using very high power pulsed lasers (with pulse energy greater than 1 J/pulse), carbon nanotubes have been produced in large quantities [Alex A. Puretzky et al., Physical Review B, Vol 65 (2002), 245425].
[0006] One drawback of high power nanosecond PLD is the generation of micron scale liquid droplets, which is mainly a result of liquid splashing and collateral damage of the target near the focal spot due to the high pulse energy. These large droplets introduce undesirable inhomogeneity to the deposition, especially in thin film growth.
[0007] In comparison to nanosecond pulsed lasers, ultrafast pulsed lasers (with a pulse duration ranging from sub-picosecond to a few picoseocnds), when used for ablation and material deposition, have the advantage of a much lower ablation threshold [by an order of magnitude, [D. Du et al., Applied Physics Letters, Vol 64 (1994), 3071 and U.S. patent U.S. Pat. No. RE 37,585]] and a resultant potential of droplet-free growth [E. G. Gamaly et al., Journal of Applied Physics, Vol 95 (2004), 2250]. The very low ablation threshold is in principle because of two reasons. First, the extremely short pulse duration means a much higher peak power. Second, because the pulse duration is shorter than the typical time scales of electron-lattice interaction and heat conduction, the heat-affected zone in ultrafast pulsed laser ablation does not extend beyond the laser focal spot. This further increases the energy density at the focal spot. Because of the much reduced size of the melt pool and collateral damage, generation of large liquid droplets can in principle be suppressed. These characteristics have made ultrafast pulsed laser ablation an emerging technology of precise laser machining and material deposition.
SUMMARY OF THE INVENTION
[0008] The present invention first provides a method of growing compound nanorods using ultrafast PLD (pulsed laser deposition) without involving external catalysts. A slight variation of this method can provide a way of switching the growth mode between nanorod growth and thin film growth. Regarding the growth mode, in the rest of the text, 1D (i.e., one-dimensional, vertical) and 2D (i.e., two-dimensional, lateral) growth are also used to refer to nanorod and thin film growth, respectively. In addition, a nanoscale porous film growth mode can also be achieved, as will be described in detail in the next section.
[0009] Although ultrafast PLD is expected to have the potential of material deposition free of large (micron scales) droplets, as introduced above, in practice, it has been found that even when the ablation is performed in vacuum, the ablation plume automatically contains much smaller particles on nanoscales [A. V. Bulgakov et al., Thin Solid Films, Vol 453 (2004), 557, S. Eliezer et al., Physical Review B, Vol 69 (2004), 144119, S. Amoruso et al., Physical Review B, Vol 71 (2005), 033406]. The inventors of the present invention have found that by controlling the laser fluence below a threshold of strong plasma formation and by providing a background gas of low pressure (<100 mTorr), ultrafast pulsed laser ablation can be an efficient method of generating single-crystalline and polycrystalline nanoparticles [B. Liu et al., Applied Physics Letters, Vol 90 (2007), 044103]. Only when the laser fluence is above the threshold of strong plasma formation the ablated material is nearly fully vaporized. These observations suggest a way of controlling the growth mode and the film morphology in ultrafast PLD.
[0010] Basically the nanorod growth involves two steps with different laser fluences. At the beginning of deposition, a thin layer of nanoparticles is first deposited by using a low laser fluence. Under this condition, the ablated material contains a large fraction of nanoparticles, and the deposited layer is a nanoparticle aggregation. After annealing, the crystallinity of this layer is improved and can serve as a seed layer to induce nanorod growth. The laser fluence is then increased to a high fluence (above the plasma threshold) to fully vaporize the ablated material. This can serve as the vapor source for the subsequent nanorod growth. FIG. 2 illustrates this two step growth method.
[0011] A slight variation of the above method can switch the growth mode to 2D thin film growth. This is realized by using the same high laser fluence throughout both growth steps. In practice, for many film/substrate systems that have large lattice mismatch between the film and substrate (e.g., ZnO/sapphire), while maintaining the same high laser fluence that can fully vaporize the source material, the first step will be performed at a low substrate temperature, providing a buffer layer. At the second step, the substrate temperature can be raised to grow the main layer. In this way, a 2D growth mode can be achieved.
[0012] A third mode can be realized to grow nanoporous films. This mode utilizes the residual amount of small particles in the ablation plume while using a medium to high laser fluence, and heating the substrate to a high temperature during growth. Examples are given for each of these growth modes.
DESCRIPTION OF THE DRAWING FIGURES
[0013] FIG. 1 is an illustration of the setup used in the current invention, including vacuum chamber 1 , laser beam 2 focusing lens 3 , targets 4 , target manipulator 5 , substrate and heater 6 , substrate manipulator 7 , ion probe 8 and gas inlet 9 . Unlabeled parts include viewports and vacuum pumps.
[0014] FIG. 2 is an illustration of the two-step growth method for nanorod growth. The laser beam used in step one produces a low fluence on the target surface. The laser beam used in step two produces a high fluence on the target surface. Nanoparticles 10 are automatically formed during low fluence ultrafast laser ablation. Seed layer 11 is formed by deposition of the nanoparticles 10 . A nearly fully vaporized plume 12 can be formed during high fluence ultrafast laser ablation.
[0015] FIG. 3 is an AFM image showing the nanoparticles deposited at a low laser fluence of 0.5 J/cm 2 . The image size is 2 μm×2 μm.
[0016] FIG. 4( a ) illustrates the dependence of plume ion current on the laser fluence, taken during ablation of ZnO. The filled squares are for p-polarization of the laser beam. Below the fluence F th at 0.6 J/cm 2 , the ion signal becomes nearly vanishing. However, significant amounts of nanoparticles can still be produced.
[0017] FIG. 4( b ) is a transient waveform of the ion signal of ablation plume. This measurement represents the time for the ions to fly from the target to the ion detector, and can provide an estimation of the speed and kinetic energy of the plume ions. The fluence of the laser for this measure is 2 J/cm 2 .
[0018] FIG. 5 is an XPS spectrum of the nitrogen 1 s level in a ZnO nanorod sample. The dot-dashed line is plot of the original data. The thick line is after curve smoothing.
[0019] FIG. 6( a ) is an SEM image of ZnO nanorods.
[0020] FIG. 6( b ) is an XRD pattern showing that the nanorods are mostly aligned along the c direction.
[0021] FIG. 7( a ) is an SEM image showing the surface of a 2D thin film of ZnO.
[0022] FIG. 7( b ) is an SEM image showing the cross-section of the 2D thin film. A smooth surface is evident.
[0023] FIG. 8( a ) is an SEM image of a nano-porous ZnO film.
[0024] FIG. 8( b ) is an XRD pattern of the nanoporous film, showing that the film is still highly textured and c-oriented.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 illustrates the experimental setup of ultrafast pulsed laser ablation used in this invention. The system basically includes a vacuum chamber for deposition (base pressure 1×10 −6 Torr) and an ultrafast pulsed laser for ablation. The chamber contains a target manipulator, a substrate manipulator, and an ion probe. Four disk-like targets can be mounted on the target manipulator. During ablation, the targets rotate and move laterally (i.e., in the target surface plane) back and forth. To improve deposition uniformity, the substrate can also rotate and move in its surface plane. The substrate heater can supply a temperature up to 1000° C. The laser used in the experiments has a pulse duration of 500 fs, a central wavelength of 1.03 μm, a pulse energy up to 100 μJ, and a repetition rate up to several hundreds of kHz. The laser is focused using a lens onto the target surface through a fused silica window. During ablation, a biased charge probe can be inserted in front of the plume to collect ions or electrons, depending on the polarity of the bias. Gases can also be supplied to the chamber during growth.
[0026] ZnO is used as a sample material in the examples below, wherein the target is a solid disk made of ZnO ceramic. But this invention is not limited to ZnO. The method can be applied to other compound materials as well, such as other metal oxides, nitrides (e.g., AlN, GaN, InN), phosphides (e.g., GaP, InP), and arsenides (e.g., GaAs, InAs). Also, pure metal targets can also be used such that the ablated metal can react with reactive gases supplied in the background. Examples of reactive gases are O 2 , N 2 , NH 3 , NO, NO 2 , N 2 O. These gases can be supplied either in their neutral form or in a plasma form.
Example of Nanorod Growth
[0027] ZnO is used as a sample compound material to illustrate the present invention. The target is a polycrystalline ZnO ceramic disk, made of ZnO powder by high pressure pressing and high temperature sintering. The target density is over 97%. The substrates are sapphire (0001). This is a representative and well-known lattice-mismatched system with a large mismatch of 32% between the film and substrate. Before growth, the substrate is first out gassed at 400° C. and exposed to an oxygen plasma to clean the hydrocarbon contaminants.
[0028] In the conventional nanorod growth using metal catalysts, it has been well-understood that the metal (typically Au) nanoclusters first form a binary alloy with Zn at the beginning of growth, and the alloyed particles trigger ZnO nanorod growth by oxidation of the segregated Zn at the alloy nanoparticles. For catalyst free growth of ZnO nanorods, a comprehensive and unanimous understanding of the growth mechanism is still lacking among different growers. In our practice of ultrafast PLD, we have found two critical factors that enable the growth of ZnO nanorod free of external catalyst. The first factor is a polycrystalline seed layer, which is produced by deposition using a low laser fluence and brief annealing; the second factor is a background gas mixture of oxygen and nitrogen. The growth procedure and the two critical factors are described in detail below.
[0029] For depositing the seed layer, a low laser fluence is typically used. There are several equivalently effective ways of reducing the laser fluence, for example, reducing the pulse energy using a neutral filter or a polarizer beam splitter, or using an aperture to clip the laser beam diameter. FIG. 3 displays an AFM image of ZnO nanoparticles procuded by using a fluence of 0.5 J/cm 2 . The average particle size is about 8 nm. The reason we choose this low fluence is as follows. FIG. 4 shows the ion signal dependence on the laser fluence taken during ablation of a ZnO target. It can be seen that below 0.6 J/cm 2 , the ion signal becomes nearly vanishing, and above 0.6 J/cm 2 , the ion signal increases very fast, indicating that for ZnO, 0.6 J/cm 2 is related to a threshold fluence (referred to as F th in the rest of the text), across which the ablation mechanism becomes different. As reported in the inventors' article [B. Liu et al., Applied Physics Letters, Vol 90 (2007), 044103], we find that below this threshold, even though the ablation appears to be very weak in ion signal (and plume brightness), a significant amount of nanoparticles are produced, as exemplified in FIG. 3 , which is a result of deposition of only one minute. After elongated deposition (≧10 min), the deposited layer will become an aggregation of nanoparticles. After annealing at an elevated temperature (≧500° C.) for 10-20 min to improve the crystallinity, this layer can serve as a seed layer for nanorod growth.
[0030] There are several possible mechanisms by which the seed layer induces 1D nanorod growth. One possibility is that the nanoparticles in the seed layer, after annealing, can become rich in Zn. Another possibility is that in a polycrystalline compound layer, the grain boundaries often contain segregated ingredients of the compound, such as Zn segregating from ZnO. In both cases, the Zn-rich parts can become ‘self-catalysts’ for the nanorod growth. In this way, the use of external catalyst such as gold is avoided, and the deposition procedure becomes simpler and the resultant material has high purity.
[0031] After preparing the seed layer, the nanorod growth can be initiated by raising the laser fluence to several times the plasma formation threshold to fully vaporize the ablated material, as illustrated in FIG. 2( b ). The substrate temperature can be set at ≧500° C. Note that 500° C. is a much lower growth temperature compared with the temperature used in other growth methods such as MBE and CVD. The reason is because that in PLD, the adatoms coming from the ablation plume are already very mobile due to the explosive fashion of ablation. The possibility of using a low growth temperature can be an advantage for many applications, for example, the growth can be performed on substrates that can not sustain high temperatures, such as glass.
[0032] For the nanorod growth, we also find that a background gas mixture of oxygen and nitrogen is indispensable. All our successful growth of nanorods are obtained when a mixture of oxygen (≧1 militorr) and nitrogen (1-20 militorr) are supplied in the chamber background. Replacing the nitrogen with argon or oxygen has not rendered nanorod growth. Our current understanding is that nitrogen radicals must have been generated during ultrafast laser ablation, and these radicals modify the ZnO surface energy anisotropy during growth, for example, by lowering the surface energy of certain planes of ZnO and promoting a more faceted growth (i.e., with more planes exposed).
[0033] Regarding the source of the nitrogen radicals, we believe it must have come from the excitation by the highly energetic ultrafast laser ablation plume. As exemplified in FIG. 4( b ), the peak time for the plume ions to reach the ion detector (3 cm away from the target) is only 0.8 micro second, which means an average kinetic energy of the plume ions of 0.8 keV (assuming Zn + ). (The ions in the leading edge of the plume can have higher kinetic energy.) These energetic ions in the plume can cause impact ionization and disassociation of the neutral nitrogen molecules in the background. FIG. 5 displays an XPS spectrum of the nitrogen is state taken from a ZnO nanorod sample. A peak at 397 eV is discernable after curve smoothing. According to reference texts, a nitrogen is peak at 397 eV indicates the existence of No, i.e., nitrogen substituting oxygen in ZnO. This peak is not observed for samples grown without introducing background nitrogen. It is worth noting that elemental nitrogen is also a well-known candidate dopant in making p-type ZnO. Our observations (e.g., the XPS measurement) suggest that neutral nitrogen can be radicalized during ultrafast pulsed ablation and can serve as a doping source.
[0034] FIG. 6( a ) shows an SEM image of a ZnO nanorod sample. The nanorods have a very narrow range of diameter, ranging from 20-60 nm, and an average length of about 200-300 nm. FIG. 6( b ) displays an XRD 0-2θ scan of the sample, which shows a predominant ZnO (0002) reflection, indicating that the nanorods are well-aligned along the c direction.
Example of Switching Growth Mode
[0035] The above example demonstrates that a seed layer made of aggregation of nanoparticles is critical to the nanorod growth, and a low laser fluence below the plasma threshold F th is important to produce the seed layer. On the other hand, if a high fluence that is several times F th and can fully vaporize the ablated material is used throughout the two growth steps, it is possible to achieve a 2D growth mode and obtain smooth thin films. FIGS. 6( a ) and 6 ( b ) are SEM images of the surface and cross-section, respectively, of a ZnO thin film grown on sapphire (0001) following such principles. Except for a number of pits, which are common in the epitaxy of large lattice-mismatched film/substrate systems, the film surface is satisfactorily smooth. The growth procedure is as follows.
[0036] The substrate is first out-gassed and cleaned in an oxygen plasma. A low temperature buffer layer is then deposited at 200-400° C. to reduce the lattice mismatch between the substrate and the main layer. The temperature is then raised to 600° C. for the main layer growth. The major difference between the 2D growth described in this example and the 1D growth described in the previous example is the laser fluence used in the first growth step: in the current example of 2D growth, a high fluence of 8 J/cm 2 is used in the first step to grow a buffer layer, while in the example of 1D growth, a low fluence of 0.5 J/cm 2 is used in the first step to grow a seed layer.
[0037] It is worth noting that in the case of 2D thin film growth, the deposition can be performed with or without nitrogen, i.e., nitrogen does not change the growth mode as long as the first step of deposition is not to create a polycrystalline seed layer. In fact, supplying a small amount (a few militorr) of nitrogen during 2D growth can even make the film slightly smoother. This is very different from the case of nanorod growth, where, in addition to the polycrystalline seed layer, nitrogen is the other necessary factors for the nanorod formation. This further emphasizes the role of the seed layer as a critical factor in determining the growth mode.
Example of Nano-Porous Film Growth
[0038] The above two examples demonstrate the effectiveness of controlling the growth mode by varying the laser fluence. The critical factor behind this is the different amount of small particles in the ablation plume, which depends on the laser fluence. Particularly, when the fluence is below the plasma formation threshold F th , there is a large fraction of nanoparticles that can be used to form the seed layer for nanorod growth. At high fluences, the mass fraction of gas phase in the plume increases fast and eventually dominates the total mass of the ablated material.
[0039] Regarding the amount of particles in the plume, in a previous work [B. Liu et al., Applied Physics Letters, Vol 90 (2007), 044103] of the inventors of the current invention, it is reported that even at high fluences up to 10 J/cm 2 , the plume still contains a small amount of small particles. These particles will also affect the growth mode, especially at high growth temperatures. FIG. 8( a ) shows a highly porous ZnO film grown at a high temperature of 700° C. using a laser fluence of 6 J/cm 2 . Note that this fluence is ten times higher than F th for ZnO. The highly porous morphology of the film is due to the residual amount of small particles, which can cause local structural disruption and strain in the film. At a high substrate temperature, when the atoms become mobile enough, they can diffuse away from the strained area. This opens a large number of small holes and results in the porous morphology. This effect is especially prominent when the substrate has a close lattice match to ZnO, for example, when using MgO substrates. Alternatively, a thin layer of MgO can be first deposited on a sapphire substrate to achieve a close lattice match to ZnO.
[0040] FIG. 8( b ) shows an XRD pattern of the film. It is evident that the film is still highly textured and oriented along the c direction. Note that the average scale of porosity of the film is on the order of a few hundreds of nanometers. The high specific surface area (and large porous volume) of this nanoscale porous film is a highly desired feature in many applications, such as sensors, catalysis (photocatalysis), magnetism, capacitors, optoelectronics, and energy storage.
[0041] In summary, the inventors have discovered new and improved techniques for forming nanorods or various films using an ultrafast PLD technique, whose enabling factors for each growth made may be reiterated as follows.
[0042] 1. 1D Nanorod Growth
a. A seed layer deposited using a low laser fluence (near or below the plasma formation threshold F th ) and annealed at an elevated temperature (≧500° C.) for an extended time (≧10 min). b. Background nitrogen of 1-50 militorr.
[0045] 2. 2D Thin Film Growth
a. A high fluence (several times higher than F th ) to fully vaporize the ablated material throughout the whole deposition process.
[0047] 3. Nanoporous Film Growth
a. A medium to high laser fluence b. A substrate with a close lattice match to the film.
[0050] All patents, patent applications and literature references referred to in this text are hereby incorporated by reference herein.
[0051] Although several embodiments of the invention have been described above, it is evident that further variations are possible as will be readily appreciated by those of skill in the art, and it will also be recognized that the embodiments may be usable together. Further, also the present text focuses on ZnO in particular, it will be recognized that the invention is applicable to other materials, and that with the apparatus of the invention, it is further possible to form films and nanorods of multiple materials within the same sample or on the same substrate, by substitution of target materials during the process of formation.
[0052] It is intended that the invention be limited only by the claims which follow, and not by the specific embodiments and their variations and combinations as described hereinabove.
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A method of producing compound nanorods and thin films under a controlled growth mode is described. The method involves ablating compound targets using an ultrafast pulsed laser and depositing the ablated materials onto a substrate. When producing compound nanorods, external catalysts such as pre-deposited metal nanoparticles are not involved. Instead, at the beginning of deposition, simply by varying the fluence at the focal spot on the target, a self-formed seed layer can be introduced for nanorods growth. This provides a simple method of producing high purity nanorods and controlling the growth mode. Three growth modes are covered by the present invention, including nanorod growth, thin film growth, and nano-porous film growth.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. ______, entitled “Stabilized Intervertebral Disc Barrier,” filed Oct. 21, 2004, which claims benefit to U.S. Provisional Application No. 60/513,437, filed Oct. 22, 2003 and U.S. Provisional Application entitled “Stabilizer for Intervertebral Disc Barrier,” filed Sep. 28, 2004, and is a continuation-in-part of co-pending U.S. application Ser. No. 10/194,428, filed Jul. 10, 2002, and is a continuation-in-part of co-pending U.S. application Ser. No. 10/055,504, filed Oct. 25, 2001, which is a continuation-in-part of U.S. application Ser. No. 09/696,636 filed on Oct. 25, 2000 which is a continuation-in-part of U.S. application Ser. No. 09/642,450 filed on Aug. 18, 2000, which is a continuation-in-part of U.S. application Ser. No. 09/608,797 filed on Jun. 30, 2000, and claims benefit to U.S. Provisional Application No. 60/311,586 filed Aug. 10, 2001, U.S. Provisional Application No. 60/149,490 filed Aug. 18, 1999, U.S. Provisional Application No. 60/161,085 filed Oct. 25, 1999 and U.S. Provisional Application No. 60/172,996 filed Dec. 21, 1999, the entire teachings of these applications being incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the surgical treatment of intervertebral discs in the lumbar, cervical, or thoracic spine that have suffered from tears in the anulus fibrosis, herniation of the nucleus pulposus and/or significant disc height loss.
[0004] 2. Description of the Related Art
[0005] The disc performs the important role of absorbing mechanical loads while allowing for constrained flexibility of the spine. The disc is composed of a soft, central nucleus pulposus (NP) surrounded by a tough, woven anulus fibrosis (AF). Herniation is a result of a weakening in the AF. Symptomatic herniations occur when weakness in the AF allows the NP to bulge or leak posteriorly toward the spinal cord and major nerve roots. The most common resulting symptoms are pain radiating along a compressed nerve and low back pain, both of which can be crippling for the patient. The significance of this problem is increased by the low average age of diagnosis, with over 80% of patients in the U.S. being under 59.
[0006] Since its original description by Mixter & Barr in 1934, discectomy has been the most common surgical procedure for treating intervertebral disc herniation. This procedure involves removal of disc materials impinging on the nerve roots or spinal cord external to the disc, generally posteriorly. Depending on the surgeon's preference, varying amounts of NP are then removed from within the disc space either through the herniation site or through an incision in the AF. This removal of extra NP is commonly done to minimize the risk of recurrent herniation.
[0007] Nevertheless, the most significant drawbacks of discectomy are recurrence of herniation, recurrence of radicular symptoms, and increasing low back pain. Re-herniation can occur in up to 21% of cases. The site for re-herniation is most commonly the same level and side as the previous herniation and can occur through the same weakened site in the AF. Persistence or recurrence of radicular symptoms happens in many patients and when not related to re-herniation, tends to be linked to stenosis of the neural foramina caused by a loss in height of the operated disc. Debilitating low back pain occurs in roughly 14% of patients. All of these failings are most directly related to the loss of NP material and AF competence that results from herniation and surgery.
[0008] Various implants, surgical meshes, patches, barriers, tissue scaffolds and the like may be used to treat intervertebral discs and are known in the art. Surgical repair meshes are used throughout the body to treat and repair damaged tissue structures such as intralinguinal hernias, herniated discs and to close iatrogenic holes and incisions as may occur elsewhere. Certain physiological environments present challenges to precise and minimally invasive delivery.
[0009] An intervertebral disc provides a dynamic environment that produces high loads and pressures. Typically implants designed for this environment must be capable of enduring such conditions for long periods of time. Also, the difficulty and danger of the implantation procedure itself, due to the proximity of the spinal cord, limits the size and ease of placement of the implant. One or more further embodiments of the invention addresses the need for a durable fatigue resistant repair mesh capable of withstanding the dynamic environment generic to intervertebral discs.
SUMMARY OF THE INVENTION
[0010] Several embodiments of the present invention relate generally to anulus augmentation devices, including, but not limited to, surgical meshes, barriers, and patches for treatment or augmentation of tissues within pathologic spinal discs. One or more embodiments comprise resilient surgical meshes that may be compressed for minimally invasive delivery and which are robust, stable, and resist fatigue and stress. These meshes are particularly well suited for intervertebral disc applications because they are durable enough to withstand intense cyclical loading and resist expulsion through a defect while not degrading over time.
[0011] Several embodiments of the present invention seek to exploit the individual characteristics of various anulus and nuclear augmentation devices to optimize the performance of both within the intervertebral disc. Accordingly, one or more of the embodiments of the present invention provide minimally invasive and removable devices for closing a defect in an anulus and augmenting the nucleus. These devices may be permanent, semi-permanent, or removable. One function of anulus augmentation devices is to prevent or minimize the extrusion of materials from within the space normally occupied by the nucleus pulposus and inner anulus fibrosus. One function of nuclear augmentation devices is to at least temporarily add material to restore diminished disc height and pressure. Nuclear augmentation devices can also induce the growth or formation of material within the nuclear space. Accordingly, the inventive combination of these devices can create a synergistic effect wherein the anulus and nuclear augmentation devices serve to restore biomechanical function in a more natural biomimetic way. Furthermore, in one embodiment, both devices may be delivered more easily and less invasively. Also, in some embodiments, the pressurized environment made possible through the addition of nuclear augmentation material and closing of the anulus serves both to restrain the nuclear augmentation and anchor the anulus augmentation in place.
[0012] As used herein, the phrase “anulus augmentation device” shall be given its ordinary meaning and shall also include devices that at least partially cover, close or seal a defect in an intervertebral disc, including, for example, barriers, meshes, patches, membranes, sealing means or closure devices. Thus, in one sense, the anulus augmentation device augments the anulus by sealing a defect in the anulus. In some embodiments, one or more barriers, meshes, patches, membranes, sealing means or closure devices comprise a support member or frame. Thus, in one embodiment, a barrier that comprises a membrane and a frame is provided. As used herein, the terms augmenting or reinforcing (and variations thereto) shall be given their ordinary meaning and shall also mean supporting, covering, closing, patching, or sealing.
[0013] In one embodiment, one or more anulus augmentation devices are provided with one or more nuclear augmentation devices. In some embodiments, the anulus barrier is integral with the nucleus augmentation. In other embodiments, at least a portion of the barrier is separate from or independent of the nuclear augmentation.
[0014] One or more of the embodiments of the present invention additionally provide an anulus augmentation device that is adapted for use with flowable nuclear augmentation material such that the flowable material cannot escape from the anulus after the anulus augmentation device has been implanted.
[0015] In one embodiment of the present invention, a disc augmentation system configured to repair or rehabilitate an intervertebral disc is provided. The system comprises at least one anulus augmentation device, and at least one nuclear augmentation material. The anulus augmentation device prevents or minimizes the extrusion of materials from within the space normally occupied by the nucleus pulposus and inner anulus fibrosus. In one application of the invention, the anulus augmentation device is configured for minimally invasive implantation and deployment. The anulus augmentation device may either be a permanent implant, or it may removable.
[0016] The nuclear augmentation material may restore diminished disc height and/or pressure. It may include factors for inducing the growth or formation of material within the nuclear space. It may either be permanent, removable, or absorbable.
[0017] The nuclear augmentation material may be in the form of liquids, gels, solids, or gases. In one embodiment, the nuclear augmentation material comprises materials selected from the group consisting of one or more of the following: steroids, antibiotics, tissue necrosis factors, tissue necrosis factor antagonists, analgesics, growth factors, genes, gene vectors, hyaluronic acid, noncross-linked collagen, collagen, fibren, liquid fat, oils, synthetic polymers, polyethylene glycol, liquid silicones, synthetic oils, saline and hydrogel. The hydrogel may be selected from the group consisting of one or more of the following: acrylonitriles, acrylic acids, polyacrylimides, acrylimides, acrylimidines, polyacrylnitriles, and polyvinyl alcohols.
[0018] Solid form nuclear augmentation materials may be in the form of geometric shapes such as cubes, spheroids, disc-like components, ellipsoid, rhombohedral, cylindrical, or amorphous. The solid material may be in powder form, and may be selected from the group consisting of one or more of the following: titanium, stainless steel, nitinol, cobalt, chrome, resorbable materials, polyurethane, polyesther, PEEK, PET, FEP, PTFE, ePTFE, PMMA, nylon, carbon fiber, Delrin, polyvinyl alcohol gels, polyglycolic acid, polyethylene glycol, silicone gel, silicone rubber, vulcanized rubber, gas-filled vesicles, bone, hydroxy apetite, collagen such as cross-linked collagen, muscle tissue, fat, cellulose, keratin, cartilage, protein polymers, transplanted nucleus pulposus, bioengineered nucleus pulposus, transplanted anulus fibrosis, and bioengineered anulus fibrosis. Structures may also be utilized, such as inflatable balloons or other inflatable containers, and spring-biased structures.
[0019] The nuclear augmentation material may additionally comprise a biologically active compound. The compound may be selected from the group consisting of one or more of the following: drug carriers, genetic vectors, genes, therapeutic agents, growth renewal agents, growth inhibitory agents, analgesics, anti-infectious agents, and anti-inflammatory drugs.
[0020] In one embodiment, the anulus augmentation device comprises materials selected from the group consisting of one or more of the following: steroids, antibiotics, tissue necrosis factors, tissue necrosis factor antagonists, analgesics, growth factors, genes, gene vectors, hyaluronic acid, noncross-linked collagen, collagen, fibren, liquid fat, oils, synthetic polymers, polyethylene glycol, liquid silicones, synthetic oils, saline, hydrogel (e.g., acrylonitriles, acrylic acids, polyacrylimides, acrylimides, acrylimidines, polyacrylnitriles, and polyvinyl alcohols), and other suitable materials.
[0021] In some embodiments, the anulus augmentation device is constructed from one or more of the following materials: titanium, stainless steel, nitinol, cobalt, chrome, resorbable materials, polyurethane, polyesther, PEEK, PET, FEP, PTFE, ePTFE, PMMA, nylon, carbon fiber, Delrin, polyvinyl alcohol gels, polyglycolic acid, polyethylene glycol, silicone gel, silicone rubber, vulcanized rubber, gas-filled vesicles, bone, hydroxy apetite, collagen such as cross-linked collagen, muscle tissue, fat, cellulose, keratin, cartilage, and protein polymers. Transplanted anulus fibrosis and bioengineered anulus fibrosis may also be used to form the barrier, sealing device, closing device or membrane. Inflatable balloons or other inflatable containers, and spring-biased structures may also be used.
[0022] The anulus augmentation device may comprise a biologically active compound. The compound may be selected from the group consisting of one or more of the following: drug carriers, genetic vectors, genes, therapeutic agents, growth renewal agents, growth inhibitory agents, analgesics, anti-infectious agents, and anti-inflammatory drugs. In some embodiments, the biologically active compound is coupled to the barrier, sealing device, closing device or membrane. In some embodiments, the biologically active compound coats the barrier, sealing device, closing device or membrane.
[0023] In one embodiment, an anulus augmentation device for reinforcing an intervertebral disc is provided. In one embodiment, the anulus augmentation device comprises a mesh frame, wherein the mesh frame comprises a plurality of flexible curvilinear members. In one embodiment, the curvalinear elements are interconnected. The interconnected curvilinear members are adapted to provide flexibility and resilience to the mesh frame. In some embodiments, the curvilinear members form a horizontal member or central strut. In one embodiment, the curvilinear members are arranged in a parallel configuration.
[0024] In one embodiment, the curvilinear members comprise a metal alloy such as steel, nickel titanium, cobalt chrome, or combinations thereof.
[0025] In some embodiments, the curvilinear members are constructed of nylon, polyvinyl alcohol, polyethylene, polyurethane, polypropylene, polycaprolactone, polyacrylate, ethylene-vinyl acetate, polystyrene, polyvinyl oxide, polyvinyl fluoride, polyvinyl imidazoles, chlorosulphonated polyolefin, polyethylene oxide, polytetrafluoroethylene, acetal, polyp-phenyleneterephtalamide) (Kevlar™), poly carbonate, carbon, graphite, or a combination thereof.
[0026] In one embodiment, a membrane encapsulates, covers or coats at least a portion of the mesh frame. In some embodiments, the membrane is coupled to the frame.
[0027] The membrane of some embodiments is constructed of polymers, elastomers, gels, elastin, albumin, collagen, fibrin, keratin, or a combination thereof. In several embodiments, the membrane comprises antibodies, antiseptics, genetic vectors, bone morphogenic proteins, steroids, cortisones, growth factors, or a combination thereof. The membrane may be a coating material.
[0028] In one embodiment, the mesh frame is concave along at least a portion of at least one axis of said mesh frame. In one embodiment, the mesh frame has a length in the range of about 0.5 cm to about 5 cm. One of skill in the art will understand that other lengths can also be used. In some embodiments, the mesh frame is sized to cover at least a portion of an interior surface of an anulus lamella. In other embodiments, the mesh frame is adapted to extend circumferentially along the entire surface of an anulus lamella.
[0029] In one embodiment, an anulus augmentation device comprising at least one projection that radiates from a mesh frame is provided. In one embodiment, the mesh frame has a vertical cross-section that is flat, concave, convex, or curvilinear. The horizontal cross-section can be concave, convex, flat, or kidney bean shaped. Other shapes can also be used.
[0030] In one embodiment of the present invention, an anulus augmentation device for reinforcing an intervertebral disc comprises a mesh frame having a horizontal axis and a vertical axis. In one embodiment, the mesh fame is concave along at least a portion the horizontal axis or the vertical axis. In one embodiment, one or more projections radiate from the horizontal axis or the vertical axis of the mesh frame. The projections are adapted to stabilize the anulus augmentation device. In one embodiment, a stabilizing projection has at least one dimension that is larger than the mesh frame. In other embodiments, the projection is smaller than the mesh frame.
[0031] In yet another embodiment of the present invention, an intervertebral disc implant comprising a posterior support member having a first terminus and a second terminus is provided. In one embodiment, an anterior projection extends outwardly from the posterior support member. The anterior projection is attached to at least the first terminus or the second terminus of the posterior support member.
[0032] In another embodiments, an intervertebral disc implant comprising a posterior support member having a first terminus and a second terminus and an anterior projection having a first end and a second end is provided. The anterior projection extends outwardly from the posterior support member. In one embodiment, the first end of the anterior projection is coupled to the first terminus of the posterior support member; and the second end of the anterior projection is coupled to the second terminus of the posterior support member, thereby substantially forming a bow-shaped implant. The posterior support member and the anterior projection can be constructed of any suitable material, including but not limited to the materials described above for the mesh frame and the membrane.
[0033] In a further embodiment of the present invention, a fatigue-resistant surgical mesh comprising rails is provided. In one embodiment, the mesh comprises a top rail, a bottom rail coupled to the top rail, wherein the top rail and said bottom rail are coupled to each other at a first end and second end. In one embodiment, the top rail and the bottom rail extend to form a gap that is defined between the rails along at least a portion of the distance between the ends.
[0034] In one embodiment of the present invention, a spinal implant for treatment of an intervertebral disc is provided. In one embodiment, a barrier or patch with a volume corresponding to the amount of material removed during a discectomy procedure is implanted. In one embodiment, the implant has a volume in a range of about 0.2 to about 2.0 cc.
[0035] In one embodiment of the invention, an intervertebral disc implant comprising a barrier forming a contiguous band is provided. In one embodiment, the band has variable heights or widths. In one embodiment, the band has different degrees of flexibility along at least one axis.
[0036] In another embodiment of the present invention, a method of repairing or rehabilitating an intervertebral disc is provided. The method comprises inserting at least one anulus augmentation device into the disc, and inserting at least one nuclear augmentation material, to be held within the disc by the anulus augmentation device. The nuclear augmentation material may conform to a first, healthy region of the anulus, while the anulus augmentation device conforms to a second, weaker region of the anulus.
[0037] In a further embodiment, a method of repairing defective regions within a spinal disc is provided. In one embodiment, the method comprises providing a surgical mesh, implanting the surgical mesh along an anulus surface, and positioning the surgical mesh at least such that about 2 mm of the device spans beyond at least one edge of the defective region of the disc.
[0038] Further features and advantages of embodiments of the present invention will become apparent to those of skill in the art in view of the detailed description of preferred embodiments which follows, when taken together with the attached drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0040] FIG. 1A shows a transverse section of a portion of a functional spine unit, in which part of a vertebra and intervertebral disc are depicted.
[0041] FIG. 1B shows a sagittal cross section of a portion of a functional spine unit shown in FIG. 1A , in which two lumbar vertebrae and the intervertebral disc are visible.
[0042] FIG. 1C shows partial disruption of the inner layers of an anulus fibrosis.
[0043] FIG. 2A shows a transverse section of one aspect of the present invention prior to supporting a herniated segment, as shown in one embodiment.
[0044] FIG. 2B shows a transverse section of the construct in FIG. 2A supporting the herniated segment.
[0045] FIG. 3A shows a transverse section of another embodiment of the disclosed invention after placement of the device.
[0046] FIG. 3B shows a transverse section of the construct in FIG. 3A after tension is applied to support the herniated segment.
[0047] FIG. 4A shows a transverse view of an alternate embodiment of the invention.
[0048] FIG. 4B shows a sagittal view of the alternate embodiment shown in FIG. 4A .
[0049] FIG. 5A shows a transverse view of another aspect of the present invention, as shown in one embodiment.
[0050] FIG. 5B shows the delivery tube of FIG. 5A being used to displace the herniated segment to within its pre-herniated borders.
[0051] FIG. 5C shows a one-piece embodiment of the invention in an anchored and supporting position.
[0052] FIG. 6 shows one embodiment of the invention supporting a weakened posterior anulus fibrosis.
[0053] FIG. 7A shows a transverse section of another aspect of the disclosed invention demonstrating two stages involved in augmentation of the soft tissues of the disc.
[0054] FIG. 7B shows a sagittal view of the invention shown in FIG. 7A .
[0055] FIG. 8 shows a transverse section of one aspect of the disclosed invention involving augmentation of the soft tissues of the disc and support/closure of the anulus fibrosis.
[0056] FIG. 9A shows a transverse section of one aspect of the invention involving augmentation of the soft tissues of the disc with the flexible augmentation material anchored to the anterior lateral anulus fibrosis.
[0057] FIG. 9B shows a transverse section of one aspect of the disclosed invention involving augmentation of the soft tissues of the disc with the flexible augmentation material anchored to the anulus fibrosis by a one-piece anchor.
[0058] FIG. 10A shows a transverse section of one aspect of the disclosed invention involving augmentation of the soft tissues of the disc.
[0059] FIG. 10B shows the construct of FIG. 10A after the augmentation material has been inserted into the disc.
[0060] FIG. 11 illustrates a transverse section of a barrier mounted within an anulus.
[0061] FIG. 12 shows a sagittal view of the barrier of FIG. 11 .
[0062] FIG. 13 shows a transverse section of a barrier anchored within a disc.
[0063] FIG. 14 illustrates a sagittal view of the barrier shown in FIG. 13 .
[0064] FIG. 15 illustrates the use of a second anchoring device for a barrier mounted within a disc.
[0065] FIG. 16A is an transverse view of the intervertebral disc.
[0066] FIG. 16B is a sagittal section along the midline of the intervertebral disc.
[0067] FIG. 17 is an axial view of the intervertebral disc with the right half of a sealing means of a barrier means being placed against the interior aspect of a defect in anulus fibrosis by a dissection/delivery tool.
[0068] FIG. 18 illustrates a full sealing means placed on the interior aspect of a defect in anulus fibrosis.
[0069] FIG. 19 depicts the sealing means of FIG. 18 being secured to tissues surrounding the defect.
[0070] FIG. 20 depicts the sealing means of FIG. 19 after fixation means have been passed into surrounding tissues.
[0071] FIG. 21A depicts an axial view of the sealing means of FIG. 20 having enlarging means inserted into the interior cavity.
[0072] FIG. 21B depicts the construct of FIG. 21 in a sagittal section.
[0073] FIG. 22A shows an alternative fixation scheme for the sealing means and enlarging means.
[0074] FIG. 22B shows the construct of FIG. 22A in a sagittal section with an anchor securing a fixation region of the enlarging means to a superior vertebral body in a location proximate to the defect.
[0075] FIG. 23A depicts an embodiment of the barrier means of the present invention being secured to an anulus using fixation means, as shown in one embodiment.
[0076] FIG. 23B depicts an embodiment of the barrier means of FIG. 23A secured to an anulus by two fixation darts wherein the fixation tool has been removed.
[0077] FIGS. 24A and 24B depict a barrier means positioned between layers of the anulus fibrosis on either side of a defect.
[0078] FIG. 25 depicts an axial cross section of a large version of a barrier means.
[0079] FIG. 26 depicts an axial cross section of a barrier means in position across a defect following insertion of two augmentation devices.
[0080] FIG. 27 depicts the barrier means as part of an elongated augmentation device.
[0081] FIG. 28A depicts an axial section of an alternate configuration of the augmentation device of FIG. 27 .
[0082] FIG. 28B depicts a sagittal section of an alternate configuration of the augmentation device of FIG. 27 .
[0083] FIGS. 29 A-D depict deployment of a barrier from an entry site remote from the defect in the anulus fibrosis.
[0084] FIGS. 30A, 30B , 31 A, 31 B, 32 A, 32 B, 33 A, and 33 B depict axial and sectional views, respectively, of various embodiments of the barrier.
[0085] FIG. 34 shows a non-axisymmetric expansion means or frame.
[0086] FIGS. 34B and 34C illustrate perspective views of a frame mounted within an intervertebral disc.
[0087] FIGS. 35 and 36 illustrate alternate embodiments of the expansion means shown in FIG. 34 .
[0088] FIGS. 37 A-C illustrate a front, side, and perspective view, respectively, of an alternate embodiment of the expansion means shown in FIG. 34 .
[0089] FIG. 38 shows an alternate expansion means to that shown in FIG. 37A .
[0090] FIGS. 39 A-D illustrate a tubular expansion means having a circular cross-section.
[0091] FIGS. 40 A-I illustrate tubular expansion means. FIGS. 40 A-D illustrate a tubular expansion means having an oval shaped cross-section. FIGS. 40E, 40F and 40 I illustrate a front, back and top view, respectively of the tubular expansion means of FIG. 40 A having a sealing means covering an exterior surface of an anulus face. FIGS. 40G and 40H show the tubular expansion means of FIG. 40A having a sealing means covering an interior surface of an anulus face.
[0092] FIGS. 41 A-D illustrate a tubular expansion means having an egg-shaped cross-section.
[0093] FIG. 42A -D depicts cross sections of a preferred embodiment of sealing and enlarging means.
[0094] FIGS. 43A and 43B depict an alternative configuration of enlarging means.
[0095] FIGS. 44A and 44B depict an alternative shape of the barrier means.
[0096] FIG. 45 is a section of a device used to affix sealing means to tissues surrounding a defect.
[0097] FIG. 46 depicts the use of a thermal device to heat and adhere sealing means to tissues surrounding a defect.
[0098] FIG. 47 depicts an expandable thermal element that can be used to adhere sealing means to tissues surrounding a defect.
[0099] FIG. 48 depicts an alternative embodiment to the thermal device of FIG. 46 .
[0100] FIGS. 49 A-G illustrate a method of implanting an intradiscal implant.
[0101] FIGS. 50 A-F show an alternate method of implanting an intradiscal implant.
[0102] FIGS. 51 A-C show another alternate method of implanting an intradiscal implant.
[0103] FIGS. 52A and 52B illustrate an implant guide used with the intradiscal implant system.
[0104] FIG. 53A illustrates a barrier having stiffening plate elements.
[0105] FIG. 53B illustrates a sectional view of the barrier of FIG. 53A .
[0106] FIG. 54A shows a stiffening plate.
[0107] FIG. 54B shows a sectional view of the stiffening plate of FIG. 54A .
[0108] FIG. 55A illustrates a barrier having stiffening rod elements.
[0109] FIG. 55B illustrates a sectional view of the barrier of FIG. 55A .
[0110] FIG. 56A illustrates a stiffening rod.
[0111] FIG. 56B illustrates a sectional view of the stiffening rod of FIG. 56A .
[0112] FIG. 57 shows an alternate configuration for the location of the fixation devices of the barrier of FIG. 44A .
[0113] FIGS. 58A and 58B illustrate a dissection device for an intervertebral disc.
[0114] FIGS. 59A and 59B illustrate an alternate dissection device for an intervertebral disc.
[0115] FIGS. 60 A-C illustrate a dissector component.
[0116] FIGS. 61 A-D illustrate a method of inserting a disc implant within an intervertebral disc.
[0117] FIG. 62 depicts a cross-sectional transverse view of a barrier device implanted within a disc along the inner surface of a lamella. Implanted conformable nuclear augmentation is also shown in contact with the barrier.
[0118] FIG. 63 shows a cross-sectional transverse view of a barrier device implanted within a disc along an inner surface of a lamella. Implanted nuclear augmentation comprised of a hydrophilic flexible solid is also shown.
[0119] FIG. 64 shows a cross-sectional transverse view of a barrier device implanted within a disc along an inner surface of a lamella. Several types of implanted nuclear augmentation including a solid geometric shape, a composite solid, and a free flowing liquid are also shown.
[0120] FIG. 65 illustrates a sagittal cross-sectional view of a barrier device connected to an inflatable nuclear augmentation device.
[0121] FIG. 66 depicts a sagittal cross-sectional view of a functional spine unit containing a barrier device unit connected to a wedge shaped nuclear augmentation device.
[0122] FIG. 67 shows an anulus augmentation device (such as a mesh) mesh having a series of curvilinear elements.
[0123] FIGS. 68 A-G show profiles and cross-sectional views of an anulus augmentation device (such as a mesh), e.g., “U” shaped, “C” shaped, curvilinear shaped, and “D” shaped to extend along and cover the entire inner anulus surface, or portions.
[0124] FIG. 69 shows one embodiment of a mesh with curvilinear elements implanted in an intervertebral disc.
[0125] FIG. 70 shows a wire-type anulus augmentation device.
[0126] FIGS. 71 A-E show a frame (e.g., mesh) that has been encapsulated by a membrane or cover to produce an encapsulated mesh.
[0127] FIGS. 72 A-B show a mesh having a double-wishbone frame.
[0128] FIGS. 73 A-C shows embodiments of the end or natural hinge portion of the frame, including a looped terminus.
[0129] FIGS. 74 A-C show some embodiments of the central band or strut.
[0130] FIGS. 75 A-L show an implant an annulus augmentation device such as a mesh having one or more projections extending into the disc or into a defect.
[0131] FIG. 76 shows an implant comprising a bow-like anterior projection that extends outwardly from a posterior support member.
[0132] FIGS. 77 A-H show various cross-sectional side views along a horizontal axis of an implant comprising a bow, band or projection.
[0133] FIGS. 78 A-J show various cross-sectional top views of implants along a vertical axis.
[0134] FIGS. 79 A-F show a frontal view of a portion of several embodiments of an implant projection.
[0135] FIGS. 80 A-D show various cross-sections of an implant projection.
[0136] FIGS. 81 A-D show looped or bent bow-type projections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0137] Several embodiments of the present invention provide for an in vivo augmented functional spine unit. A functional spine unit includes the bony structures of two adjacent vertebrae (or vertebral bodies), the soft tissue (anulus fibrosis (AF), and optionally nucleus pulposus (NP)) of the intervertebral disc, and the ligaments, musculature and connective tissue connected to the vertebrae. The intervertebral disc is substantially situated in the intervertebral space formed between the adjacent vertebrae. Augmentation of the functional spine unit can include repair of a herniated disc segment, support of a weakened, torn or damaged anulus fibrosis, or the addition of material to or replacement of all or part of the nucleus pulposus. Augmentation of the functional spine unit is provided by herniation constraining devices and disc augmentation devices situated in the intervertebral disc space.
[0138] FIGS. 1A and 1B show the general anatomy of a functional spine unit 45 . In this description and the following claims, the terms ‘anterior’ and ‘posterior’, ‘superior’ and ‘inferior’ are defined by their standard usage in anatomy, i.e., anterior is a direction toward the front (ventral) side of the body or organ, posterior is a direction toward the back (dorsal) side of the body or organ; superior is upward (toward the head) and inferior is lower (toward the feet).
[0139] FIG. 1A is an axial view along the transverse axis M of a vertebral body with the intervertebral disc 15 superior to the vertebral body. Axis M shows the anterior (A) and posterior (P) orientation of the functional spine unit within the anatomy. The intervertebral disc 15 contains the anulus fibrosis (AF) 10 which surrounds a central nucleus pulposus (NP) 20 . A Herniated segment 30 is depicted by a dashed-line. The herniated segment 30 protrudes beyond the pre-herniated posterior border 40 of the disc. Also shown in this figure are the left 70 and right 70 ′ transverse spinous processes and the posterior spinous process 80 .
[0140] FIG. 1B is a sagittal section along sagittal axis N through the midline of two adjacent vertebral bodies 50 (superior) and 50 ′ (inferior). Intervertebral disc space 55 is formed between the two vertebral bodies and contains intervertebral disc 15 , which supports and cushions the vertebral bodies and permits movement of the two vertebral bodies with respect to each other and other adjacent functional spine units.
[0141] Intervertebral disc 15 is comprised of the outer AF 10 which normally surrounds and constrains the NP 20 to be wholly within the borders of the intervertebral disc space. In FIGS. 1A and 1B , herniated segment 30 , represented by the dashed-line, has migrated posterior to the pre-herniated border 40 of the posterior AF of the disc. Axis M extends between the anterior (A) and posterior (P) of the functional spine unit. The vertebral bodies also include facet joints 60 and the superior 90 and inferior 90 ′ pedicle that form the neural foramen 100 . Disc height loss occurs when the superior vertebral body 50 moves inferiorly relative to the inferior vertebral body 50 ′.
[0142] Partial disruption 121 of the inner layers of the anulus 10 without a true perforation has also been linked to chronic low back pain. Such a disruption 4 is illustrated in FIG. 1C . It is thought that weakness of these inner layers forces the sensitive outer anulus lamellae to endure higher stresses. This increased stress stimulates the small nerve fibers penetrating the outer anulus, which results in both localized and referred pain.
[0143] In one embodiment of the present invention, the disc herniation constraining devices 13 provide support for returning all or part of the herniated segment 30 to a position substantially within its pre-herniated borders 40 . The disc herniation constraining device includes an anchor which is positioned at a site within the functional spine unit, such as the superior or inferior vertebral body, or the anterior medial, or anterior lateral anulus fibrosis. The anchor is used as a point against which all or part of the herniated segment is tensioned so as to return the herniated segment to its pre-herniated borders, and thereby relieve pressure on otherwise compressed neural tissue and structures. A support member is positioned in or posterior to the herniated segment, and is connected to the anchor by a connecting member. Sufficient tension is applied to the connecting member so that the support member returns the herniated segment to a pre-herniated position. In various embodiments, augmentation material is secured within the intervertebral disc space, which assists the NP in cushioning and supporting the inferior and superior vertebral bodies. An anchor secured in a portion of the functional spine unit and attached to the connection member and augmentation material limits movement of the augmentation material within the intervertebral disc space. A supporting member, located opposite the anchor, may optionally provide a second point of attachment for the connection member and further hinder the movement of the augmentation material within the intervertebral disc space.
[0144] FIGS. 2A and 2B depict one embodiment of device 13 . FIG. 2A shows the elements of the constraining device in position to correct the herniated segment. Anchor 1 is securely established in a location within the functional spine unit, such as the anterior AF shown in the figure. Support member 2 is positioned in or posterior to herniated segment 30 . Leading from and connected to anchor 1 is connection member 3 , which serves to connect anchor 1 to support member 2 . Depending on the location chosen for support member 2 , the connection member may traverse through all or part of the herniated segment.
[0145] FIG. 2B shows the positions of the various elements of the herniation constraining device 13 when the device 13 is supporting the herniated segment. Tightening connection member 2 allows it to transmit tensile forces along its length, which causes herniated segment 30 to move anteriorly, i.e., in the direction of its pre-herniated borders. Once herniated segment 30 is in the desired position, connection member 3 is secured in a permanent fashion between anchor 1 and support member 2 . This maintains tension between anchor 1 and support member 2 and restricts motion of the herniated segment to within the pre-herniated borders 40 of the disc. Support member 2 is used to anchor to herniated segment 30 , support a weakened AF in which no visual evidence of herniation is apparent, and may also be used to close a defect in the AF in the vicinity of herniated segment 30 .
[0146] Anchor 1 is depicted in a representative form, as it can take one of many suitable shapes, be made from one of a variety of biocompatible materials, and be constructed so as to fall within a range of stiffness. It can be a permanent device constructed of durable plastic or metal or can be made from a resorbable material such as polylactic acid (PLA) or polyglycolic acid (PGA). Specific embodiments are not shown, but many possible designs would be obvious to anyone skilled in the art. Embodiments include, but are not limited to, a barbed anchor made of PLA or a metal coil that can be screwed into the anterior AF. Anchor 1 can be securely established within a portion of the functional spine unit in the usual and customary manner for such devices and locations, such as being screwed into bone, sutured into tissue or bone, or affixed to tissue or bone using an adhesive method, such as cement, or other suitable surgical adhesives. Once established within the bone or tissue, anchor 1 should remain relatively stationary within the bone or tissue.
[0147] Support member 2 is also depicted in a representative format and shares the same flexibility in material and design as anchor 1 . Both device elements can be of the same design, or they can be of different designs, each better suited to being established in healthy and diseased tissue respectively. Alternatively, in other forms, support member 2 can be a cap or a bead shape, which also serves to secure a tear or puncture in the AF, or it can be bar or plate shaped, with or without barbs to maintain secure contact with the herniated segment. Support member 2 can be established securely to, within, or posterior to the herniated segment.
[0148] The anchor and support member can include suture, bone anchors, soft tissue anchors, tissue adhesives, and materials that support tissue ingrowth although other forms and materials are possible. They may be permanent devices or resorbable. Their attachment to a portion of FSU and herniated segment must be strong enough to resist the tensional forces that result from repair of the hernia and the loads generated during daily activities.
[0149] Connection member 3 is also depicted in representative fashion. Member 3 may be in the format of a flexible filament, such as a single or multi-strand suture, wire, or perhaps a rigid rod or broad band of material, for example. The connection member can further include suture, wire, pins, and woven tubes or webs of material. It can be constructed from a variety of materials, either permanent or resorbable, and can be of any shape suitable to fit within the confines of the intervertebral disc space. The material chosen is preferably adapted to be relatively stiff while in tension, and relatively flexible against all other loads. This allows for maximal mobility of the herniated segment relative to the anchor without the risk of the supported segment moving outside of the pre-herniated borders of the disc. The connection member may be an integral component of either the anchor or support member or a separate component. For example, the connection member and support member could be a length of non-resorbing suture that is coupled to an anchor, tensioned against the anchor, and sewn to the herniated segment.
[0150] FIGS. 3A and 3B depict another embodiment of device 13 . In FIG. 3A the elements of the herniation constraining device are shown in position prior to securing a herniated segment. Anchor 1 is positioned in the AF and connection member 3 is attached to anchor 1 . Support member 4 is positioned posterior to the posterior-most aspect of herniated segment 30 . In this way, support member 4 does not need to be secured in herniated segment 30 to cause herniated segment 30 to move within the pre-herniated borders 40 of the disc. Support member 4 has the same flexibility in design and material as anchor 1 , and may further take the form of a flexible patch or rigid plate or bar of material that is either affixed to the posterior aspect of herniated segment 30 or is simply in a form that is larger than any hole in the AF directly anterior to support member 4 . FIG. 3B shows the positions of the elements of the device when tension is applied between anchor 1 and support member 4 along connection member 3 . The herniated segment is displaced anteriorly, within the pre-herniated borders 40 of the disc.
[0151] FIGS. 4A and 4B show five examples of suitable anchoring sites within the FSU for anchor 1 . FIG. 4A shows an axial view of anchor 1 in various positions within the anterior and lateral AF. FIG. 4B similarly shows a sagittal view of the various acceptable anchoring sites for anchor 1 . Anchor 1 is secured in the superior vertebral body 50 , inferior vertebral body 50 ′ or anterior AF 10 , although any site that can withstand the tension between anchor 1 and support member 2 along connection member 3 to support a herniated segment within its pre-herniated borders 40 is acceptable.
[0152] Generally, a suitable position for affixing one or more anchors is a location anterior to the herniated segment such that, when tension is applied along connection member 3 , herniated segment 30 is returned to a site within the pre-herniated borders 40 . The site chosen for the anchor should be able to withstand the tensile forces applied to the anchor when the connection member is brought under tension. Because most symptomatic herniations occur in the posterior or posterior lateral directions, the preferable site for anchor placement is anterior to the site of the herniation. Any portion of the involved FSU is generally acceptable, however the anterior, anterior medial, or anterior lateral AF is preferable. These portions of the AF have been shown to have considerably greater strength and stiffness than the posterior or posterior lateral portions of the AF. As shown in FIGS. 4A and 4B , anchor 1 can be a single anchor in any of the shown locations, or there can be multiple anchors 1 affixed in various locations and connected to a support member 2 to support the herniated segment. Connection member 3 can be one continuous length that is threaded through the sited anchors and the support member, or it can be several individual strands of material each terminated under tension between one or more anchors and one or more support members.
[0153] In various forms of the invention, the anchor(s) and connection member(s) may be introduced and implanted in the patient, with the connection member under tension. Alternatively, those elements may be installed, without introducing tension to the connection member, but where the connection member is adapted to be under tension when the patient is in a non-horizontal position, e.g., resulting from loading in the intervertebral disc.
[0154] FIGS. 5 A-C show an alternate embodiment of herniation constraining device 13 A. In this series of figures, device 13 A, a substantially one-piece construct, is delivered through a delivery tube 6 , although device 13 A could be delivered in a variety of ways including, but not limited to, by hand or by a hand held grasping instrument. In FIG. 5A , device 13 A in delivery tube 6 is positioned against herniated segment 30 . In FIG. 5B , the herniated segment is displaced within its pre-herniated borders 40 by device 13 A and/or delivery tube 6 such that when, in FIG. 5C , device 13 A has been delivered through delivery tube 6 , and secured within a portion of the FSU, the device supports the displaced herniated segment within its pre-herniated border 40 . Herniation constraining device 13 A can be made of a variety of materials and have one of many possible forms so long as it allows support of the herniated segment 30 within the pre-herniated borders 40 of the disc. Device 13 A can anchor the herniated segment 30 to any suitable anchoring site within the FSU, including, but not limited to the superior vertebral body, inferior vertebral body, or anterior AF. Device 13 A may be used additionally to close a defect in the AF of herniated segment 30 . Alternatively, any such defect may be left open or may be closed using another means.
[0155] FIG. 6 depicts the substantially one-piece device 13 A supporting a weakened segment 30 ′ of the posterior AF 10 ′. Device 13 A is positioned in or posterior to the weakened segment 30 ′ and secured to a portion of the FSU, such as the superior vertebral body 50 , shown in the figure, or the inferior vertebral body 50 ′ or anterior or anterior-lateral anulus fibrosis 10 . In certain patients, there may be no obvious herniation found at surgery. However, a weakened or torn AF that may not be protruding beyond the pre-herniated borders of the disc may still induce the surgeon to remove all or part of the NP in order to decrease the risk of herniation. As an alternative to discectomy, any of the embodiments of the invention may be used to support and perhaps close defects in weakened segments of AF.
[0156] A further embodiment of the present invention involves augmentation of the soft tissues of the intervertebral disc to avoid or reverse disc height loss. FIGS. 7A and 7B show one embodiment of device 13 securing augmentation material in the intervertebral disc space 55 . In the left side of FIG. 7A , anchors 1 have been established in the anterior AF 10 . Augmentation material 7 is in the process of being inserted into the disc space along connection member 3 which, in this embodiment, has passageway 9 . Support member 2 ′ is shown ready to be attached to connection member 3 once the augmentation material 7 is properly situated. In this embodiment, connection member 3 passes through an aperture 11 in support member 2 ′, although many other methods of affixing support member 2 ′ to connection member 3 are possible and within the scope of this invention.
[0157] Augmentation material 7 may have a passageway 9 , such as a channel, slit or the like, which allows it to slide along the connection member 3 , or augmentation material 7 may be solid, and connection member 3 can be threaded through augmentation material by means such as needle or other puncturing device. Connection member 3 is affixed at one end to anchor 1 and terminated at its other end by a support member 2 ′, one embodiment of which is shown in the figure in a cap-like configuration. Support member 2 ′ can be affixed to connection member 3 in a variety of ways, including, but not limited to, swaging support member 2 ′ to connection member 3 . In a preferred embodiment, support member 2 ′ is in a cap configuration and has a dimension (diameter or length and width) larger than the optional passageway 9 , which serves to prevent augmentation material 7 from displacing posteriorly with respect to anchor 1 . The right half of the intervertebral disc of FIG. 7A (axial view) and FIG. 7B (sagittal view) show augmentation material 7 that has been implanted into the disc space 55 along connection member 3 where it supports the vertebral bodies 50 and 50 ′. FIG. 7A shows an embodiment in which support member 2 ′ is affixed to connection member 3 and serves only to prevent augmentation material 7 from moving off connection member 3 . The augmentation device is free to move within the disc space. FIG. 7B shows an alternate embodiment in which support member 2 ′ is embedded in a site in the functional spine unit, such as a herniated segment or posterior anulus fibrosis, to further restrict the movement of augmentation material 7 or spacer material within the disc space.
[0158] Augmentation or spacer material can be made of any biocompatible, preferably flexible, material. Such a flexible material is preferably fibrous, like cellulose or bovine or autologous collagen. The augmentation material can be plug or disc shaped. It can further be cube-like, ellipsoid, spheroid or any other suitable shape. The augmentation material can be secured within the intervertebral space by a variety of methods, such as but not limited to, a suture loop attached to, around, or through the material, which is then passed to the anchor and support member.
[0159] Figures 0 . 8 , 9 A, 9 B and 10 A and 10 B depict further embodiments of the disc herniation constraining device 13 B in use for augmenting soft tissue, particularly tissue within the intervertebral space. In the embodiments shown in FIGS. 8 and 9 A, device 13 B is secured within the intervertebral disc space providing additional support for NP 20 . Anchor 1 is securely affixed in a portion of the FSU, (anterior AF 10 in these figures). Connection member 3 terminates at support member 2 , preventing augmentation material 7 from migrating generally posteriorly with respect to anchor 1 . Support member 2 is depicted in these figures as established in various locations, such as the posterior AF 10 ′ in FIG. 8 , but support member 2 may be anchored in any suitable location within the FSU, as described previously. Support member 2 may be used to close a defect in the posterior AF. It may also be used to displace a herniated segment to within the pre-herniated borders of the disc by applying tension between anchoring means 1 and 2 along connection member 3 .
[0160] FIG. 9A depicts anchor 1 , connection member 3 , spacer material 7 and support member 2 ′ (shown in the “cap”-type configuration) inserted as a single construct and anchored to a site within the disc space, such as the inferior or superior vertebral bodies. This configuration simplifies insertion of the embodiments depicted in FIGS. 7 and 8 by reducing the number of steps to achieve implantation. Connection member 3 is preferably relatively stiff in tension, but flexible against all other loads. Support member 2 ′ is depicted as a bar element that is larger than passageway 9 in at least one plane.
[0161] FIG. 9B depicts a variation on the embodiment depicted in FIG. 9A . FIG. 9B shows substantially one-piece disc augmentation device 13 C, secured in the intervertebral disc space. Device 13 C has anchor 1 , connection member 3 and augmentation material 7 . Augmentation material 7 and anchor 1 could be pre-assembled prior to insertion into the disc space 55 as a single construct. Alternatively, augmentation material 7 could be inserted first into the disc space and then anchored to a portion of the FSU by anchor 1 .
[0162] FIGS. 10A and 10B show yet another embodiment of the disclosed invention, 13 D. In FIG. 10A , two connection members 3 and 3 ′ are attached to anchor 1 . Two plugs of augmentation material 7 and 7 ′ are inserted into the disc space along connection members 3 and 3 ′. Connection members 3 and 3 ′ are then bound together (e.g., knotted together, fused, or the like). This forms loop 3 ″ that serves to prevent augmentation materials 7 and 7 ′ from displacing posteriorly. FIG. 10B shows the position of the augmentation material 7 after it is secured by the loop 3 ″ and anchor 1 . Various combinations of augmentation material, connecting members and anchors can be used in this embodiment, such as using a single plug of augmentation material, or two connection members leading from anchor 1 with each of the connection members being bound to at least one other connection member. It could further be accomplished with more than one anchor with at least one connection member leading from each anchor, and each of the connection members being bound to at least one other connection member.
[0163] Any of the devices described herein can be used for closing defects in the AF whether created surgically or during the herniation event. Such methods may also involve the addition of biocompatible material to either the AF or NP. This material could include sequestered or extruded segments of the NP found outside the pre-herniated borders of the disc.
[0164] FIGS. 11-15 illustrate devices used in and methods for closing a defect in an anulus fibrosis. One method involves the insertion of a barrier or barrier means 12 into the disc 15 . This procedure can accompany surgical discectomy. It can also be done without the removal of any portion of the disc 15 and further in combination with the insertion of an augmentation material or device into the disc 15 .
[0165] The method consists of inserting the barrier 12 into the interior of the disc 15 and positioning it proximate to the interior aspect of the anulus defect 16 . The barrier material is preferably considerably larger in area than the size of the defect 16 , such that at least some portion of the barrier means 12 abuts healthier anulus fibrosis 10 . The device acts to seal the anulus defect 16 , recreating the closed isobaric environment of a healthy disc nucleus 20 . This closure can be achieved simply by an over-sizing of the implant relative to the defect 16 . It can also be achieved by affixing the barrier means 12 to tissues within the functional spinal unit. In one embodiment of the present invention, the barrier 12 is affixed to the anulus surrounding the anulus defect 16 . This can be achieved with sutures, staples, glues or other suitable fixation means or fixation device 14 . The barrier means 12 can also be larger in area than the defect 16 and be affixed to a tissue or structure opposite the defect 16 , e.g., anterior tissue in the case of a posterior defect.
[0166] The barrier means 12 is preferably flexible in nature. It can be constructed of a woven material such as Dacron™ or Nylon™, a synthetic polyamide or polyester, a polyethylene, and can further be an expanded material, such as expanded polytetrafluroethylene (e-PTFE), for example. The barrier means 12 can also be a biologic material such as cross-linked collagen or cellulous.
[0167] The barrier means 12 can be a single piece of material. It can have an expandable means or component that allows it to be expanded from a compressed state after insertion into the interior of the disc 15 . This expandable means can be active, such as a balloon, or passive, such as a hydrophilic material. The expandable means can also be a self-expanding elastically deforming material, for example.
[0168] FIGS. 11 and 12 illustrate a barrier 12 mounted within an anulus 10 and covering an anulus defect 16 . The barrier 12 can be secured to the anulus 10 with a fixation mechanism or fixation means 14 . The fixation means 14 can include a plurality of suture loops placed through the barrier 12 and the anulus 10 . Such fixation can prevent motion or slipping of the barrier 12 away from the anulus defect 16 .
[0169] The barrier means 12 can also be anchored to the disc 15 in multiple locations. In one preferred embodiment, shown in FIGS. 13 and 14 , the barrier means 12 can be affixed to the anulus tissue 10 in or surrounding the defect and further affixed to a secondary fixation site opposite the defect, e.g. the anterior anulus 10 in a posterior herniation, or the inferior 50 ′ or superior 50 vertebral body. For example, fixation means 14 can be used to attach the barrier 12 to the anulus 10 near the defect 16 , while an anchoring mechanism 18 can secure the barrier 12 to a secondary fixation site. A connector 22 can attach the barrier 12 to the anchor 18 . Tension can be applied between the primary and secondary fixation sites through a connector 22 so as to move the anulus defect 16 toward the secondary fixation site. This may be particularly beneficial in closing defects 16 that result in posterior herniations. By using this technique, the herniation can be moved and supported away from any posterior neural structures while further closing any defect in the anulus 10 .
[0170] The barrier means 12 can further be integral to a fixation means such that the barrier means affixes itself to tissues within the functional spinal unit.
[0171] Any of the methods described above can be augmented by the use of a second barrier or a second barrier means 24 placed proximate to the outer aspect of the defect 16 as shown in FIG. 15 . The second barrier 24 can further be affixed to the inner barrier means 12 by the use of a fixation means 14 such as suture material.
[0172] FIGS. 16A and 16B depict intervertebral disc 15 comprising nucleus pulposus 20 and anulus fibrosis 10 . Nucleus pulposus 20 forms a first anatomic region and extra-discal space 500 (any space exterior to the disc) forms a second anatomic region wherein these regions are separated by anulus fibrosis 10 .
[0173] FIG. 16A is an axial (transverse) view of the intervertebral disc. A posterior lateral defect 16 in anulus fibrosis 10 has allowed a segment 30 of nucleus pulposus 20 to herniate into an extra discal space 500 . Interior aspect 32 and exterior aspect 34 are shown, as are the right 70 ′ and left 70 transverse processes and posterior process 80 .
[0174] FIG. 16B is a sagittal section along the midline intervertebral disc. Superior pedicle 90 and inferior pedicle 90 ′ extend posteriorly from superior vertebral body 95 and inferior vertebral body 95 ′ respectively.
[0175] To prevent further herniation of the nucleus 20 and to repair any present herniation, in a preferred embodiment, a barrier or barrier means 12 can be placed into a space between the anulus 10 and the nucleus 20 proximate to the inner aspect 32 of defect 16 , as depicted in FIGS. 17 and 18 . The space can be created by blunt dissection. Dissection can be achieved with a separate dissection instrument, with the barrier means 12 itself, or a combined dissection/barrier delivery tool 100 . This space is preferably no larger than the barrier means such that the barrier means 12 can be in contact with both anulus 10 and nucleus 20 . This allows the barrier means 12 to transfer load from the nucleus 20 to the anulus 10 when the disc is pressurized during activity.
[0176] In position, the barrier means 12 preferably spans the defect 16 and extends along the interior aspect 36 of the anulus 10 until it contacts healthy tissues on all sides of the defect 16 , or on a sufficient extent of adjacent healthy tissue to provide adequate support under load. Healthy tissue may be non-diseased tissue and/or load bearing tissue, which may be micro-perforated or non-perforated. Depending on the extent of the defect 16 , the contacted tissues can include the anulus 10 , cartilage overlying the vertebral endplates, and/or the endplates themselves.
[0177] In the preferred embodiment, the barrier means 12 comprises two components—a sealing means or sealing component 51 and an enlarging means or enlarging component 53 , shown in FIGS. 21A and 21B .
[0178] The sealing means 51 forms the periphery of the barrier 12 and has an interior cavity 17 . There is at least one opening 8 leading into cavity 17 from the exterior of the sealing means 51 . Sealing means 51 is preferably compressible or collapsible to a dimension that can readily be inserted into the disc 15 through a relatively small hole. This hole can be the defect 16 itself or a site remote from the defect 16 . The sealing means 51 is constructed from a material and is formed in such a manner as to resist the passage of fluids and other materials around sealing means 51 and through the defect 16 . The sealing means 51 can be constructed from one or any number of a variety of materials including, but not limited to PTFE, e-PTFE, Nylon™, Marlex™, high-density polyethylene, and/or collagen. The thickness of the sealing component has been found to be optimal between about 0.001 inches (0.127 mm) and 0.063 inches (1.6 mm).
[0179] The enlarging means 53 can be sized to fit within cavity 17 of sealing means 51 . It is preferably a single object of a dimension that can be inserted through the same defect 16 through which the sealing means 51 was passed. The enlarging means 53 can expand the sealing means 51 to an expanded state as it is passed into cavity 17 . One purpose of enlarging means 53 is to expand sealing means 51 to a size greater than that of the defect 16 such that the assembled barrier 12 prevents passage of material through the defect 16 . The enlarger 53 can further impart stiffness to the barrier 12 such that the barrier 12 resists the pressures within nucleus pulposus 20 and expulsion through the defect 16 . The enlarging means 53 can be constructed from one or any number of materials including, but not limited to, silicon rubber, various plastics, stainless steel, nickel titanium alloys, or other metals. These materials may form a solid object, a hollow object, coiled springs or other suitable forms capable of filling cavity 17 within sealing means 51 .
[0180] The sealing means 51 , enlarging means 53 , or the barrier means 12 constructs can further be affixed to tissues either surrounding the defect 16 or remote from the defect 16 . In the preferred embodiment, no aspect of a fixation means or fixation device or the barrier means 12 nor its components extend posterior to the disc 15 or into the extradiscal region 500 , avoiding the risk of contacting and irritating the sensitive nerve tissues posterior to the disc 15 .
[0181] In a preferred embodiment, the sealing means 51 is inserted into the disc 15 proximate the interior aspect 36 of the defect. The sealing means 51 is then affixed to the tissues surrounding the defect using a suitable fixation means, such as suture or a soft-tissue anchor. The fixation procedure is preferably performed from the interior of the sealing means cavity 17 as depicted in FIGS. 19 and 20 . A fixation delivery instrument 110 is delivered into cavity 17 through opening 8 in the sealing means 51 . Fixation devices 14 can then be deployed through a wall of the sealing means 53 into surrounding tissues. Once the fixation means 14 have been passed into surrounding tissue, the fixation delivery instrument 110 can be removed from the disc 15 . This method eliminates the need for a separate entryway into the disc 15 for delivery of fixation means 14 . It further minimizes the risk of material leaking through sealing means 51 proximate to the fixation means 14 . One or more fixation means 14 can be delivered into one or any number of surrounding tissues including the superior 95 and inferior 95 ′ vertebral bodies. Following fixation of the sealing means 51 , the enlarging means 53 can be inserted into cavity 17 of the sealing means 51 to further expand the barrier means 12 construct as well as increase its stiffness, as depicted in FIGS. 21A and 21B . The opening 8 into the sealing means 51 can then be closed by a suture or other means, although this is not a requirement of the present invention. In certain cases, insertion of a separate enlarging means may not be necessary if adequate fixation of the sealing means 51 is achieved.
[0182] Another method of securing the barrier 12 to tissues is to affix the enlarging means 53 to tissues either surrounding or remote from the defect 16 . The enlarging means 53 can have an integral fixation region 4 that facilitates securing it to tissues as depicted in FIGS. 22A, 22B , 32 A and 43 B. This fixation region 4 can extend exterior to sealing means 51 either through opening 8 or through a separate opening. Fixation region 4 can have a hole through which a fixation means or fixation device 14 can be passed. In a preferred embodiment, the barrier 12 is affixed to at least one of the surrounding vertebral bodies ( 95 and 95 ′) proximate to the defect using a bone anchor 14 ′. The bone anchor 14 ′ can be deployed into the vertebral bodies 50 , 50 ′ at some angle between 0 E and 180 E relative to a bone anchor deployment tool. As shown the bone anchor 14 ′ is mounted at 90 E relative to the bone anchor deployment tool. Alternatively, the enlarging means 53 itself can have an integral fixation device 14 located at a site or sites along its length.
[0183] Another method of securing the barrier means 12 is to insert the barrier means 12 through the defect 16 or another opening into the disc 15 , position it proximate to the interior aspect 36 of the defect 16 , and pass at least one fixation means 14 through the anulus 10 and into the barrier 12 . In a preferred embodiment of this method, the fixation means 14 can be darts 15 and are first passed partially into anulus 10 within a fixation device 120 , such as a hollow needle. As depicted in FIGS. 23A and 23B , fixation means 25 can be advanced into the barrier means 12 and fixation device 120 removed. Fixation means 25 preferably have two ends, each with a means to prevent movement of that end of the fixation device. Using this method, the fixation means can be lodged in both the barrier 12 and anulus fibrosis 10 without any aspect of fixation means 25 exterior to the disc in the extradiscal region 500 .
[0184] In several embodiments of the present invention, the barrier (or “patch”) 12 can be placed between two neighboring layers 33 , 37 (lamellae) of the anulus 10 on either or both sides of the defect 16 as depicted in FIGS. 24A and 24B . FIG. 24A shows an axial view while 24 B shows a sagittal cross section. Such positioning spans the defect 16 . The barrier means 12 can be secured using the methods outlined.
[0185] A dissecting tool can be used to form an opening extending circumferentially 31 within the anulus fibrosis such that the barrier can be inserted into the opening. Alternatively, the barrier itself can have a dissecting edge such that it can be driven at least partially into the sidewalls of defect 16 , annulotomy 416 , access hole 417 or opening in the anulus. This process can make use of the naturally layered structure in the anulus in which adjacent layers 33 , 37 are defined by a circumferentially extending boundary 35 between the layers.
[0186] Another embodiment of the barrier 12 is a patch having a length, oriented along the circumference of the disc, which is substantially greater than its height, which is oriented along the distance separating the surrounding vertebral bodies. A barrier 12 having a length greater than its height is illustrated in FIG. 25 . The barrier 12 can be positioned across the defect 16 as well as the entirety of the posterior aspect of the anulus fibrosis 10 . Such dimensions of the barrier 12 can help to prevent the barrier 12 from slipping after insertion and can aid in distributing the pressure of the nucleus 20 evenly along the posterior aspect of the anulus 10 .
[0187] The barrier 12 can be used in conjunction with an augmentation device 11 inserted within the anulus 10 . The augmentation device 11 can include separate augmentation devices 42 as shown in FIG. 26 . The augmentation device 11 can also be a single augmentation device 44 and can form part of the barrier 12 as barrier region 300 , coiled within the anulus fibrosis 10 , as shown in FIG. 27 . Either the barrier 12 or barrier region 300 can be secured to the tissues surrounding the defect 16 by fixation devices or darts 25 , or be left unconstrained
[0188] In another embodiment of the present invention, the barrier or patch 12 may be used as part of a method to augment the intervertebral disc. In one aspect of this method, augmentation material or devices are inserted into the disc through a defect (either naturally occurring or surgically generated). Many suitable augmentation materials and devices are discussed above and in the prior art. As depicted in FIG. 26 , the barrier means is then inserted to aid in closing the defect and/or to aid in transferring load from the augmentation materials/devices to healthy tissues surrounding the defect. In another aspect of this method, the barrier means is an integral component to an augmentation device. As shown in FIGS. 27, 28A and 28 B, the augmentation portion may comprise a length of elastic material that can be inserted linearly through a defect in the anulus. A region 300 of the length forms the barrier means of some embodiments of the present invention and can be positioned proximate to the interior aspect of the defect once the nuclear space is adequately filled. Barrier region 300 may then be affixed to surrounding tissues such as the AF and/or the neighboring vertebral bodies using any of the methods and devices described above.
[0189] FIGS. 28A and 28B illustrate axial and sagittal sections, respectively, of an alternate configuration of an augmentation device 38 . In this embodiment, barrier region 300 extends across the defect 16 and has fixation region 4 facilitating fixation of the device 13 to superior vertebral body 50 with anchor 14 ′.
[0190] FIGS. 29 A-D illustrate the deployment of a barrier 12 from an entry site 800 remote from the defect in the anulus fibrosis 10 . FIG. 29A shows insertion instrument 130 with a distal end positioned within the disc space occupied by nucleus pulposus 20 . FIG. 29B depicts delivery catheter 140 exiting the distal end of insertion instrument 130 with barrier 12 on its distal end. Barrier 12 is positioned across the interior aspect of the defect 16 . FIG. 29C depicts the use of an expandable barrier 12 ′ wherein delivery catheter 140 is used to expand the barrier 12 ′ with balloon 150 on its distal end. Balloon 150 may exploit heat to further adhere barrier 12 ′ to surrounding tissue. FIG. 29D depicts removal of balloon 150 and delivery catheter 140 from the disc space leaving expanded barrier means 12 ′ positioned across defect 16 .
[0191] Another method of securing the barrier means 12 is to adhere it to surrounding tissues through the application of heat. In this embodiment, the barrier means 12 includes a sealing means 51 comprised of a thermally adherent material that adheres to surrounding tissues upon the application of heat. The thermally adherent material can include thermoplastic, collagen, or a similar material. The sealing means 51 can further comprise a separate structural material that adds strength to the thermally adherent material, such as a woven Nylon™ or Marlex™. This thermally adherent sealing means preferably has an interior cavity 17 and at least one opening 8 leading from the exterior of the barrier means into cavity 17 . A thermal device can be attached to the insertion instrument shown in FIGS. 29C and 29D . The insertion instrument 130 having a thermal device can be inserted into cavity 17 and used to heat sealing means 51 and surrounding tissues. This device can be a simple thermal element, such as a resistive heating coil, rod or wire. It can further be a number of electrodes capable of heating the barrier means and surrounding tissue through the application of radio frequency (RF) energy. The thermal device can further be a balloon 150 , 150 ′, as shown in FIG. 47 , capable of both heating and expanding the barrier means. Balloon 150 , 150 ′ can either be inflated with a heated fluid or have electrodes located about its surface to heat the barrier means with RF energy. Balloon 150 , 150 ′ is deflated and removed after heating the sealing means. These thermal methods and devices achieve the goal of adhering the sealing means to the AF and NP and potentially other surrounding tissues. The application of heat can further aid the procedure by killing small nerves within the AF, by causing the defect to shrink, or by causing cross-linking and/or shrinking of surrounding tissues. An expander or enlarging means 53 can also be an integral component of barrier 12 inserted within sealing means 51 . After the application of heat, a separate enlarging means 53 can be inserted into the interior cavity of the barrier means to either enlarge the barrier 12 or add stiffness to its structure. Such an enlarging means is preferably similar in make-up and design to those described above. Use of an enlarging means may not be necessary in some cases and is not a required component of this method.
[0192] The barrier means 12 shown in FIG. 25 preferably has a primary curvature or gentle curve along the length of the patch or barrier 12 that allows it to conform to the inner circumference of the AF 10 . This curvature may have a single radius R as shown in FIGS. 44A and 44B or may have multiple curvatures. The curvature can be fabricated into the barrier 12 and/or any of its components. For example, the sealing means can be made without an inherent curvature while the enlarging means can have a primary curvature along its length. Once the enlarging means is placed within the sealing means the overall barrier means assembly takes on the primary curvature of the enlarging means. This modularity allows enlarging means with specific curvatures to be fabricated for defects occurring in various regions of the anulus fibrosis.
[0193] The cross section of the barrier 12 can be any of a number of shapes. Each embodiment exploits a sealing means 51 and an enlarging means 53 that may further add stiffness to the overall barrier construct. FIGS. 30A and 30B show an elongated cylindrical embodiment with enlarging means 53 located about the long axis of the device. FIGS. 31A and 31B depict a barrier means comprising an enlarging means 53 with a central cavity 49 . FIGS. 32A and 32B depict a barrier means comprising a non-axisymmetric sealing means 51 . In use, the longer section of sealing means 51 as seen on the left side of this figure would extend between opposing vertebra 50 and 50 ′. FIGS. 33A and 33B depict a barrier means comprising a non-axisymmetric sealing means 51 and enlarger 53 . The concave portion of the barrier means preferably faces nucleus pulposus 20 while the convex surface faces the defect 16 , annulotomy 416 , or access hole 417 and the inner aspect of the anulus fibrosis 10 . This embodiment exploits pressure within the disc to compress sealing means 51 against neighboring vertebral bodies 50 and 50 ′ to aid in sealing. The ‘C’ shape as shown in FIG. 33A is the preferred shape of the barrier wherein the convex portion of the patch rests against the interior aspect of the AF while the concave portion faces the NP. Used in this manner, the barrier or patch 12 serves to partially encapsulate the nucleus puposus 20 by conforming to the gross morphology of the inner surface of the anulus 10 and presenting a concave or cupping surface toward the nucleus 20 . To improve the sealing ability of such a patch, the upper and lower portions of this ‘C’ shaped barrier means are positioned against the vertebral endplates or overlying cartilage. As the pressure within the nucleus increases, these portions of the patch are pressurized toward the endplates with an equivalent pressure, preventing the passage of materials around the barrier means. Dissecting a matching cavity prior to or during patch placement can facilitate use of such a ‘C’ shaped patch.
[0194] FIGS. 34 through 41 depict various enlarging or expansion devices 53 that can be employed to aid in expanding a sealing element 51 within the intervertebral disc 15 . Each embodiment can be covered by, coated with, or cover the sealing element 51 . The sealing means 51 can further be woven through the expansion means 53 . The sealing element 51 or membrane can be a sealer which can prevent flow of a material from within the anulus fibrosis of the intervertebral disc through a defect in the anulus fibrosis. The material within the anulus can include nucleus pulposus or a prosthetic augmentation device, such as a hydrogel.
[0195] FIGS. 34 through 38 depict alternative patterns to that illustrated in FIG. 33A . FIG. 33A shows the expansion devices 53 within the sealing means 51 . The sealing means can alternatively be secured to one or another face (concave or convex) of the expansion means 53 . This can have advantages in reducing the overall volume of the barrier means 12 , simplifying insertion through a narrow cannula. It can also allow the barrier means 12 to induce ingrowth of tissue on one face and not the other. The sealing means 51 can be formed from a material that resists ingrowth such as expanded polytetraflouroethylene (e-PTFE). The expansion means 53 can be constructed of a metal or polymer that encourages ingrowth. In several embodiments, if the e-PTFE sealing means 51 is secured to the concave face of the expansion means 53 , tissue can grow into the expansion means 53 from outside of the disc 15 , helping to secure the barrier means 12 in place and seal against egress of materials from within the disc 15 .
[0196] The expansion means 53 shown in FIG. 33A can be inserted into the sealing means 51 once the sealing means 51 is within the disc 15 . Alternatively, the expansion means 53 and sealing means 51 can be integral components of the barrier means 12 that can be inserted as a unit into the disc.
[0197] The patterns shown in FIGS. 34 through 38 can preferably be formed from a relatively thin sheet of material. The material may be a polymer, metal, or gel, however, the superelastic properties of nickel titanium alloy (NITINOL) makes this metal particularly advantageous in this application. Sheet thickness can generally be in a range of about 0.1 mm to about 0.6 mm and for certain embodiments has been found to be optimal if between about 0.003″ to about 0.015″ (0.0762 mm to 0.381 mm), for the thickness to provide adequate expansion force to maintain contact between the sealing means 51 and surrounding vertebral endplates. The pattern may be Wire Electro-Discharge Machined, cut by laser, chemically etched, or formed by other suitable means.
[0198] FIG. 34 shows an embodiment of a non-axisymmetric expander 153 having a superior edge 166 and an inferior edge 168 . The expander 153 can form a frame of barrier 12 . This embodiment comprises dissecting surfaces or ends 160 , radial elements or fingers 162 and a central strut 164 . The circular shape of the dissecting ends 160 aids in dissecting through the nucleus pulposus 20 and/or along or between an inner surface of the anulus fibrosis 10 . The distance between the left-most and right-most points on the dissecting ends is the expansion means length 170 . This length 170 preferably lies along the inner perimeter of the posterior anulus following implantation. The expander length 170 can be as short as about 3 mm and as long as the entire interior perimeter of the anulus fibrosis. The superior-inferior height of these dissecting ends 160 is preferably similar to or larger than the posterior disc height.
[0199] This embodiment employs a multitude of fingers 162 to aid in holding a flexible sealer or membrane against the superior and inferior vertebral endplates. The distance between the superior-most point of the superior finger and the inferior-most point on the inferior finger is the expansion means height 172 . This height 172 is preferably greater than the disc height at the inner surface of the posterior anulus. The greater height 172 of the expander 153 allows the fingers 162 to deflect along the superior and inferior vertebral endplates, enhancing the seal of the barrier means 12 against egress of material from within the disc 15 .
[0200] The spacing between the fingers 162 along the expander length 170 can be tailored to provide a desired stiffness of the expansion means 153 . Greater spacing between any two neighboring fingers 162 can further be employed to insure that the fingers 170 do not touch if the expansion means 153 is required to take a bend along its length. The central strut 164 can connect the fingers and dissecting ends and preferably lies along the inner surface of the anulus 10 when seated within the disc 15 . Various embodiments may employ struts 164 of greater or lesser heights and thicknesses to vary the stiffness of the overall expansion means 153 along its length 170 and height 172 .
[0201] FIG. 35 depicts an alternative embodiment to the expander 153 of FIG. 34 . Openings or slots 174 can be included along the central strut 164 . These slots 174 promote bending of the expander 153 and fingers 162 along a central line 176 connecting the centers of the dissecting ends 160 . Such central flexibility has been found to aid against superior or inferior migration of the barrier means or barrier 12 when the barrier 12 has not been secured to surrounding tissues.
[0202] FIGS. 34B and 34C depict different perspective views of a preferred embodiment of the expander/frame 153 within an intervertebral disc 15 . Expander 53 is in its expanded condition and lies along and/or within the posterior wall 21 and extends around the lateral walls 23 of the anulus fibrosis 10 . The superior 166 and inferior 168 facing fingers 162 of expander 153 extend along the vertebral endplates (not shown) and/or the cartilage overlying the endplates. The frame 153 can take on a 3-D concave shape in this preferred position with the concavity generally directed toward the interior of the intervertebral disc and specifically a region occupied by the nucleus pulposus 20 .
[0203] The bending stiffness of expander 153 can resist migration of the implant from this preferred position within the disc 15 . The principle behind this stiffness-based stability is to place the regions of expander 153 with the greatest flexibility in the regions of the disc 153 with the greatest mobility or curvature. These flexible regions of expander 153 are surrounded by significantly stiffer regions. Hence, in order for the implant to migrate, a relatively stiff region of the expander must move into a relatively curved or mobile region of the disc.
[0204] For example, in order for expander 153 of FIG. 34B to move around the inner circumference of anulus fibrosis 10 (e.g., from the posterior wall 21 onto the lateral 23 and/or anterior 27 wall), the stiff central region of expander 153 spanning the posterior wall 21 would have to bend around the acute curves of the posterior lateral corners of anulus 10 . The stiffer this section of expander 153 is, the higher the forces necessary to force it around these corners and the less likely it is to migrate in this direction. This principle was also used in this embodiment to resist migration of fingers 162 away from the vertebral endplates: The slots 174 cut along the length of expander 153 create a central flexibility that encourages expander 153 to bend along an axis running through these slots as the posterior disc height increases and decreased during flexion and extension. In order for the fingers 162 to migrate away from the endplate, this central flexible region must move away from the posterior anulus 21 and toward an endplate. This motion is resisted by the greater stiffness of expander 153 in the areas directly inferior and superior to this central flexible region.
[0205] The expander 153 is preferably covered by a membrane that acts to further restrict the movement of materials through the frame and toward the outer periphery of the anulus fibrosis.
[0206] FIG. 36 depicts an embodiment of the expander 153 of FIG. 33A with an enlarged central strut 164 and a plurality of slots 174 . This central strut 164 can have a uniform stiffness against superior-inferior 166 and 168 bending as shown in this embodiment. The strut 164 can alternatively have a varying stiffness along its height 178 to either promote or resist bending at a given location along the inner surface of the anulus 10 .
[0207] FIGS. 37 A-C depict a further embodiment of the frame or expander 153 . This embodiment employs a central lattice 180 consisting of multiple, fine interconnected struts 182 . Such a lattice 180 can provide a structure that minimizes bulging of the sealing means 51 under intradiscal pressures. The orientation and location of these struts 182 have been designed to give the barrier 12 a bend-axis along the central area of the expander height 172 . The struts 182 support inferior 168 and superior 166 fingers 162 similar to previously described embodiments. However, these fingers 162 can have varying dimensions and stiffness along the length of the barrier 12 . Such fingers 162 can be useful for helping the sealer 51 conform to uneven endplate geometries. FIG. 37B illustrates the curved cross section 184 of the expander 153 of FIG. 37A . This curve 184 can be an arc segment of a circle as shown. Alternatively, the cross section can be an ellipsoid segment or have a multitude of arc segments of different radii and centers. FIG. 37C is a perspective view showing the three dimensional shape of the expander 153 of FIGS. 37A and 37B .
[0208] The embodiment of the frame 153 as shown in FIGS. 37 A-C, can also be employed without the use of a covering membrane. The nucleus pulposus of many patients with low back pain or disc herniation can degenerate to a state in which the material properties of the nucleus cause it to behave much more like a solid than a gel. As humans age, the water content of the nucleus declines from roughly 88% to less than 75%. As this occurs, there is an increase in the cross linking of collagen within the disc resulting in a greater solidity of the nucleus. When the pore size or the largest open area of any given gap in the lattice depicted in FIGS. 37A-37C is between about 0.05 mm 2 (7.75×10 −5 in 2 ) and about 0.75 mm 2 (1.16×10 −3 in 2 ), the nucleus pulposus is unable to extrude through the lattice at pressures generated within the disc (between about 250 KPa and about 1.8 MPa). The preferred pore size has been found to be approximately 0.15 mm 2 (2.33×10 −4 in 2 ). This pore size can be used with any of the disclosed embodiments of the expander or any other expander that falls within the scope of embodiments of the invention to prevent movement of nucleus toward the outer periphery of the disc without the need for an additional membrane. The membrane thickness is preferably in a range of about 0.025 mm to about 2.5 mm.
[0209] FIG. 38 depicts an expander 153 similar to that of FIG. 37A without fingers. The expander 153 includes a central lattice 180 consisting of multiple struts 182 .
[0210] FIGS. 39 through 41 depict another embodiment of the expander 153 of some embodiments of the present invention. These tubular expanders can be used in the barrier 12 embodiment depicted in FIG. 31A . The sealer 51 can cover the expander 153 as shown in FIG. 31A . Alternatively, the sealer 51 can cover the interior surface of the expander or an arc segment of the tube along its length on either the interior or exterior surface.
[0211] FIG. 39 depicts an embodiment of a tubular expander 154 . The superior 166 and inferior surfaces 168 of the tubular expander 154 can deploy against the superior and inferior vertebral endplates, respectively. The distance 186 between the superior 166 and inferior 168 surfaces of the expander 154 are preferably equal to or greater than the posterior disc height at the inner surface of the anulus 10 . This embodiment has an anulus face 188 and nucleus face 190 as shown in FIGS. 39B, 39C and 39 D. The anulus face 188 can be covered by the sealer 51 from the superior 166 to inferior 168 surface of the expander 154 . This face 188 lies against the inner surface of the anulus 10 in its deployed position and can prevent egress of materials from within the disc 15 . The primary purpose of the nucleus face 190 is to prevent migration of the expander 154 within the disc 15 . The struts 192 that form the nucleus face 190 can project anteriorly into the nucleus 20 when the barrier 12 is positioned across the posterior wall of the anulus 10 . This anterior projection can resist rotation of the tubular expansion means 154 about its long axis. By interacting with the nucleus 20 , the struts 192 can further prevent migration around the circumference of the disc 15 .
[0212] The struts 192 can be spaced to provide nuclear gaps 194 . These gaps 194 can encourage the flow of nucleus pulposus 20 into the interior of the expander 154 . This flow can insure full expansion of the barrier 12 within the disc 15 during deployment.
[0213] The embodiments of FIGS. 39, 40 and 41 vary by their cross-sectional shape. FIG. 39 has a circular cross section 196 as seen in FIG. 39C . If the superior-inferior height 186 of the expander 154 is greater than that of the disc 15 , this circular cross section 196 can deform into an oval when deployed, as the endplates of the vertebrae compress the expander 154 . The embodiment of the expander 154 shown in FIG. 40 is preformed into an oval shape 198 shown in FIG. 40C . Compression by the endplates can exaggerate the unstrained oval 198 . This oval 198 can provide greater stability against rotation about a long axis of the expander 154 . The embodiment of FIGS. 41B, 41C and 41 D depict an ‘egg-shaped’ cross section 202 , as shown in FIG. 41C , that can allow congruity between the curvature of the expander 154 and the inner wall of posterior anulus 10 . Any of a variety of alternate cross sectional shapes can be employed to obtain a desired fit or expansion force without deviating from the spirit of the present invention.
[0214] FIGS. 40E, 40F , and 40 I depict the expander 154 of FIGS. 40 A-D having a sealing means 51 covering the exterior surface of the anulus face 188 . This sealing means 51 can be held against the endplates and the inner surface of the posterior anulus by the expander 154 in its deployed state.
[0215] FIGS. 40G and 40H depict the expander 154 of FIG. 40B with a sealer 51 covering the interior surface of the anulus face 188 . This position of the sealer 51 can allow the expander 154 to contact both the vertebral endplates and inner surface of the posterior anulus. This can promote ingrowth of tissue into the expander 154 from outside the disc 15 . Combinations of sealer 51 that cover all or part of the expander 154 can also be employed without deviating from the scope of the present invention. The expander 154 can also have a small pore size thereby allowing retention of a material such as a nucleus pulposus, for example, without the need for a sealer as a covering.
[0216] FIGS. 42 A-D depict cross sections of a preferred embodiment of sealing means 51 and enlarging means 53 . Sealing means 51 has internal cavity 17 and opening 8 leading from its outer surface into internal cavity 17 . Enlarger 53 can be inserted through opening 8 and into internal cavity 17 .
[0217] FIGS. 43A and 43B depict an alternative configuration of enlarger 53 . Fixation region 4 extends through opening 8 in sealing means 51 . Fixation region 4 has a through-hole that can facilitate fixation of enlarger 53 to tissues surrounding defect 16 .
[0218] FIGS. 44A and 44B depict an alternative shape of the barrier. In this embodiment, sealing means 51 , enlarger 53 , or both have a curvature with radius R. This curvature can be used in any embodiment of the present invention and may aid in conforming to the curved inner circumference of anulus fibrosis 10 .
[0219] FIG. 45 is a section of a device used to affix sealing means 51 to tissues surrounding a defect. In this figure, sealing means 51 would be positioned across interior aspect 50 of defect 16 . The distal end of device 110 ′ would be inserted through defect 16 and opening 8 into the interior cavity 17 . On the right side of this figure, fixation dart 25 has been passed from device 110 ′, through a wall of sealing means 51 and into tissues surrounding sealing means 51 . On the right side of the figure, fixation dart 25 is about to be passed through a wall of sealing means 51 by advancing pusher 111 relative to device 110 ′ in the direction of the arrow.
[0220] FIG. 46 depicts the use of thermal device 200 to heat sealing means 51 and adhere it to tissues surrounding a defect. In this figure, sealing means 51 would be positioned across the interior aspect 36 of a defect 16 . The distal end of thermal device 200 would be inserted through the defect and opening 8 into interior cavity 17 . In this embodiment, thermal device 200 employs at its distal end resistive heating element 210 connected to a voltage source by wires 220 . Covering 230 is a non-stick surface such as Teflon tubing that ensures the ability to remove device 200 from interior cavity 17 . In this embodiment, device 200 would be used to heat first one half, and then the other half of sealing means 51 .
[0221] FIG. 47 depicts an expandable thermal element, such as a balloon, that can be used to adhere sealing means 51 to tissues surrounding a defect. As in FIG. 18 , the distal end of device 130 can be inserted through the defect and opening 8 into interior cavity 17 , with balloon 150 ′ on the distal end device 130 in a collapsed state. Balloon 150 ′ is then inflated to expanded state 150 , expanding sealing means 51 . Expanded balloon 150 can heat sealing means 51 and surrounding tissues by inflating it with a heated fluid or by employing RF electrodes. In this embodiment, device 130 can be used to expand and heat first one half, then the other half of sealing means 51 .
[0222] FIG. 48 depicts an alternative embodiment to device 130 . This device employs an elongated, flexible balloon 150 ′ that can be inserted into and completely fill internal cavity 17 of sealing means 51 prior to inflation to an expanded state 150 . Using this embodiment, inflation and heating of sealing means 51 can be performed in one step.
[0223] FIGS. 49A through 49G illustrate a method of implanting an intradiscal implant. An intradiscal implant system consists of an intradiscal implant 400 , a delivery device or cannula 402 , an advancer 404 and at least one control filament 406 . The intradiscal implant 400 is loaded into the delivery cannula 402 which has a proximal end 408 and a distal end 410 . FIG. 49A illustrates the distal end 410 advanced into the disc 15 through an annulotomy 416 . This annulotomy 416 can be through any portion of the anulus 10 , but is preferably at a site proximate to a desired, final implant location. The implant 400 is then pushed into the disc 15 through the distal end 410 of the cannula 402 in a direction that is generally away from the desired, final implant location as shown in FIG. 49B . Once the implant 400 is completely outside of the delivery cannula 402 and within the disc 15 , the implant 400 can be pulled into the desired implant location by pulling on the control filament 406 as shown in FIG. 49C . The control filament 406 can be secured to the implant 400 at any location on or within the implant 400 , but is preferably secured at least at a site 414 or sites on a distal portion 412 of the implant 400 , e.g., that portion that first exits the delivery cannula 402 when advanced into the disc 15 . These site or sites 414 are generally furthest from the desired, final implant location once the implant has been fully expelled from the interior of the delivery cannula 402 .
[0224] Pulling on the control filament 406 causes the implant 400 to move toward the annulotomy 416 . The distal end 410 of the delivery cannula 402 can be used to direct the proximal end 420 of the implant 400 (that portion of the implant 400 that is last to be expelled from the delivery cannula 402 ) away from the annulotomy 416 and toward an inner aspect of the anulus 10 nearest the desired implant location. Alternately, the advancer 404 can be used to position the proximal end of the implant toward an inner aspect of the anulus 20 near the implant location, as shown in FIG. 49E . Further pulling on the control filament 406 causes the proximal end 426 of the implant 400 to dissect along the inner aspect of the anulus 20 until the attachment site 414 or sites of the guide filament 406 to the implant 400 has been pulled to the inner aspect of the annulotomy 416 , as shown in FIG. 49D . In this way, the implant 400 will extend at least from the annulotomy 416 and along the inner aspect of the anulus 10 in the desired implant location, illustrated in FIG. 49F .
[0225] The implant 400 can be any one of the following (including a combination of two or more of the following): nucleus replacement device, nucleus augmentation device, anulus augmentation device, anulus replacement device, the barrier of the present invention or any of its components, drug carrier device, carrier device seeded with living cells, or a device that stimulates or supports fusion of the surrounding vertebra. The implant 400 can be a membrane which prevents the flow of a material from within the anulus fibrosis of an intervertebral disc through a defect in the disc. The material within the anulus fibrosis can be, for example, a nucleus pulposus or a prosthetic augmentation device, such as hydrogel. The membrane can be a sealer. The implant 400 can be wholly or partially rigid or wholly or partially flexible. It can have a solid portion or portions that contain a fluid material. It can comprise a single or multitude of materials. These materials can include metals, polymers, gels and can be in solid or woven form. The implant 400 can either resist or promote tissue ingrowth, whether fibrous or bony.
[0226] The cannula 402 can be any tubular device capable of advancing the implant 400 at least partially through the anulus 10 . It can be made of any suitable biocompatible material including various known metals and polymers. It can be wholly or partially rigid or flexible. It can be circular, oval, polygonal, or irregular in cross section. It must have an opening at least at its distal end 410 , but can have other openings in various locations along its length.
[0227] The advancer 404 can be rigid or flexible, and have one of a variety of cross sectional shapes either like or unlike the delivery cannula 402 . It may be a solid or even a column of incompressible fluid, so long as it is stiff enough to advance the implant 400 into the disc 15 . The advancer 404 can be contained entirely within the cannula 402 or can extend through a wall or end of the cannula to facilitate manipulation.
[0228] Advancement of the implant 400 can be assisted by various levers, gears, screws and other secondary assist devices to minimize the force required by the surgeon to advance the implant 400 . These secondary devices can further give the user greater control over the rate and extent of advancement into the disc 15 .
[0229] The guide filament 406 may be a string, rod, plate, or other elongate object that can be secured to and move with the implant 400 as it is advanced into the disc 15 . It can be constructed from any of a variety of metals or polymers or combination thereof and can be flexible or rigid along all or part of its length. It can be secured to a secondary object 418 or device at its end opposite that which is secured to the implant 400 . This secondary device 418 can include the advancer 404 or other object or device that assists the user in manipulating the filament. The filament 406 can be releasably secured to the implant 400 , as shown in FIG. 49G or permanently affixed. The filament 406 can be looped around or through the implant; Such a loop can either be cut or have one end pulled until the other end of the loop releases the implant 400 . It may be bonded to the implant 400 using adhesive, welding, or a secondary securing means such as a screw, staple, dart, etc. The filament 406 can further be an elongate extension of the implant material itself. If not removed following placement of the implant, the filament 406 can be used to secure the implant 400 to surrounding tissues such as the neighboring anulus 10 , vertebral endplates, or vertebral bodies either directly or through the use of a dart, screw, staple, or other suitable anchor.
[0230] Multiple guide filaments can be secured to the implant 400 at various locations. In one preferred embodiment, a first or distal 422 and a second or proximal 424 guide filament are secured to an elongate implant 400 at or near its distal 412 and proximal 420 ends at attachment sites 426 and 428 , respectively. These ends 412 and 420 correspond to the first and last portions of the implant 400 , respectively, to be expelled from the delivery cannula 402 when advanced into the disc 15 . This double guide filament system allows the implant 400 to be positioned in the same manner described above in the single filament technique, and illustrated in FIGS. 50 A-C. However, following completion of this first technique, the user may advance the proximal end 420 of the device 400 across the annulotomy 416 by pulling on the second guide filament 424 , shown in FIG. 50D . This allows the user to controllably cover the annulotomy 416 . This has numerous advantages in various implantation procedures. This step may reduce the risk of herniation of either nucleus pulposus 20 or the implant itself. It may aid in sealing the disc, as well as preserving disc pressure and the natural function of the disc. It may encourage ingrowth of fibrous tissue from outside the disc into the implant. It may further allow the distal end of the implant to rest against anulus further from the defect created by the annulotomy. Finally, this technique allows both ends of an elongate implant to be secured to the disc or vertebral tissues.
[0231] Both the first 422 and second 424 guide filaments can be simultaneously tensioned, as shown in FIG. 50E , to ensure proper positioning of the implant 400 within the anulus 10 . Once the implant 400 is placed across the annulotomy, the first 422 and second 424 guide filaments can be removed from the input 400 , as shown in FIG. 50F . Additional control filaments and securing sites may further assist implantation and/or fixation of the intradiscal implants.
[0232] In another embodiment of the present invention, as illustrated in FIGS. 51 A-C, an implant guide 430 may be employed to aid directing the implant 400 through the annulotomy 416 , through the nucleus pulposus 10 , and/or along the inner aspect of the anulus 10 . This implant guide 430 can aid in the procedure by dissecting through tissue, adding stiffness to the implant construct, reducing trauma to the anulus or other tissues that can be caused by a stiff or abrasive implant, providing 3-D control of the implants orientation during implantation, expanding an expandable implant, or temporarily imparting a shape to the implant that is beneficial during implantation. The implant guide 430 can be affixed to either the advancer 404 or the implant 406 themselves. In a preferred embodiment shown in FIGS. 52A and 52B , the implant guide 430 is secured to the implant 400 by the first 424 and second 426 guide filaments of the first 426 and the second 428 attachment sites, respectively. The guide filaments 424 and 426 may pass through or around the implant guide 430 . In this embodiment, the implant guide 430 may be a thin, flat sheet of biocompatible metal with holes passing through its surface proximate to the site or sites 426 and 428 at which the guide filaments 422 and 424 are secured to the implant 400 . These holes allow passage of the securing filament 422 and 424 through the implant guide 430 . Such an elongated sheet may run along the implant 400 and extend beyond its distal end 412 . The distal end of the implant guide 430 may be shaped to help dissect through the nucleus 10 and deflect off of the anulus 10 as the implant 400 is advanced into the disc 15 . When used with multiple guide filaments, such an implant guide 430 can be used to control rotational stability of the implant 400 . It may also be used to retract the implant 400 from the disc 15 should this become necessary. The implant guide 430 may also extend beyond the proximal tip 420 of the implant 400 to aid in dissecting across or through the anulus 10 proximate to the desired implantation site.
[0233] The implant guide 430 is releasable from the implant 400 following or during implantation. This release may be coordinated with the release of the guide filaments 422 and 424 . The implant guide 430 may further be able to slide along the guide filaments 422 and 424 while these filaments are secured to the implant 400 .
[0234] Various embodiments of the barrier 12 or implant 400 can be secured to tissues within the intervertebral disc 15 or surrounding vertebrae. It can be advantageous to secure the barrier means 12 in a limited number of sites while still insuring that larger surfaces of the barrier 12 or implant juxtapose the tissue to which the barrier 12 is secured. This is particularly advantageous in forming a sealing engagement with surrounding tissues.
[0235] FIGS. 53-57 illustrate barriers 12 having stiffening elements 300 . The barrier 12 can incorporate stiffening elements 300 that run along a length of the implant required to be in sealing engagement. These stiffening elements 300 can be one of a variety of shapes including, but not limited to, plates 302 , rods 304 , or coils. These elements are preferably stiffer than the surrounding barrier 12 and can impart their stiffness to the surrounding barrier. These stiffening elements 300 can be located within an interior cavity formed by the barrier. They can further be imbedded in or secured to the barrier 12 .
[0236] Each stiffening element can aid in securing segments of the barrier 12 to surrounding tissues. The stiffening elements can have parts 307 , including through-holes, notches, or other indentations for example, to facilitate fixation of the stiffening element 300 to surrounding tissues by any of a variety of fixation devices 306 . These fixation devices 306 can include screws, darts, dowels, or other suitable means capable of holding the barrier 12 to surrounding tissue. The fixation devices 306 can be connected either directly to the stiffening element 300 or indirectly using an intervening length of suture, cable, or other filament for example. The fixation device 306 can further be secured to the barrier 12 near the stiffening element 300 without direct contact with the stiffening element 300 .
[0237] The fixation device 306 can be secured to or near the stiffening element 300 at opposing ends of the length of the barrier 12 required to be in sealing engagement with surrounding tissues. Alternatively, one or a multitude of fixation devices 306 can be secured to or near the stiffening element 300 at a readily accessible location that may not be at these ends. In any barrier 12 embodiment with an interior cavity 17 and an opening 8 leading thereto, the fixation sites may be proximal to the opening 8 to allow passage of the fixation device 306 and various instruments that may be required for their implantation.
[0238] FIGS. 53A and 53B illustrate one embodiment of a barrier 12 incorporating the use of a stiffening element 300 . The barrier 12 can be a plate and screw barrier 320 . In this embodiment, the stiffening element 300 consists of two fixation plates, superior 310 and inferior 312 , an example of which is illustrated in FIGS. 54A and 54B with two parts 308 passing through each plate. The parts 308 are located proximal to an opening 8 leading into an interior cavity 17 of the barrier 12 . These parts 8 allow passage of a fixation device 306 such as a bone screw. These screws can be used to secure the barrier means 12 to a superior 50 and inferior 50 ′ vertebra. As the screws are tightened against the vertebral endplate, the fixation plates 310 , 312 compress the intervening sealing means against the endplate along the superior and inferior surfaces of the barrier 12 . This can aid in creating a sealing engagement with the vertebral endplates and prevent egress of materials from within the disc 15 . As illustrated in FIGS. 53A and 53B , only the superior screws have been placed in the superior plate 310 , creating a sealing engagement with the superior vertebra.
[0239] FIGS. 55A and 55B illustrate another embodiment of a barrier 12 having stiffening elements 300 . The barrier 12 can be an anchor and rod barrier 322 . In this embodiment, the stiffening elements 300 consist of two fixation rods 304 , an example of which is shown in FIGS. 56A and 56B , imbedded within the barrier 12 . The rods 304 can include a superior rod 314 and an inferior rod 316 . Sutures 318 can be passed around these rods 314 and 316 and through the barrier means 10 . These sutures 318 can in turn, be secured to a bone anchor or other suitable fixation device 306 to draw the barrier 12 into sealing engagement with the superior and inferior vertebral endplates in a manner similar to that described above. The opening 8 and interior cavity 17 of the barrier 12 are not required elements of the barrier 12 .
[0240] FIG. 57 illustrates the anchor and rod barrier 322 , described above, with fixation devices 306 placed at opposing ends of each fixation rod 316 and 318 . The suture 18 on the left side of the superior rod 318 has yet to be tied.
[0241] Various methods may be employed to decrease the forces necessary to maneuver the barrier 12 into a position along or within the lamellae of the anulus fibrosis 10 . FIGS. 58A, 58B , 59 A and 59 B depict two preferred methods of clearing a path for the barrier 12 .
[0242] FIGS. 58A and 58B depict one such method and an associated dissector device 454 . In these figures, the assumed desired position of the implant is along the posterior anulus 452 . In order to clear a path for the implant, a hairpin dissector 454 can be passed along the intended implantation site of the implant. The hairpin dissector 454 can have a hairpin dissector component 460 having a free end 458 . The dissector can also have an advancer 464 to position the dissector component 460 within the disc 15 . The dissector 454 can be inserted through cannula 456 into an opening 462 in the anulus 10 along an access path directed anteriorly or anterior-medially. Once a free-end 458 of the dissector component 460 is within the disc 15 , the free-end 458 moves slightly causing the hairpin to open, such that the dissector component 460 resists returning into the cannula 456 . This opening 462 can be caused by pre-forming the dissector to the opened state. The hairpin dissector component 460 can then be pulled posteriorly, causing the dissector component 460 to open, further driving the free-end 458 along the posterior anulus 458 . This motion clears a path for the insertion of any of the implants disclosed in the present invention. The body of dissector component 460 is preferably formed from an elongated sheet of metal. Suitable metals include various spring steels or nickel titanium alloys. It can alternatively be formed from wires or rods.
[0243] FIGS. 59A and 59B depict another method and associated dissector device 466 suitable for clearing a path for implant insertion. The dissector device 466 is shown in cross section and consists of a dissector component 468 , an outer cannula 470 and an advancer or inner push rod 472 . A curved passage or slot 474 is formed into an intradiscal tip 476 of outer cannula 470 . This passage or slot 474 acts to deflect the tip of dissector component 468 in a path that is roughly parallel to the lamellae of the anulus fibrosis 10 as the dissector component 468 is advanced into the disc 15 by the advancer. The dissector component 468 is preferably formed from a superelastic nickel titanium alloy, but can be constructed of any material with suitable rigidity and strain characteristics to allow such deflection without significant plastic deformation. The dissector component 468 can be formed from an elongated sheet, rods, wires or the like. It can be used to dissect between the anulus 10 and nucleus 20 , or to dissect between layers of the anulus 10 .
[0244] FIGS. 60 A-C depict an alternate dissector component 480 of FIGS. 59A and 59B . Only the intradiscal tip 476 of device 460 and regions proximal thereto are shown in these figures. A push-rod 472 similar to that shown in FIG. 59A can be employed to advance dissector 480 into the disc 15 . Dissector 480 can include an elongated sheet 482 with superiorly and inferiorly extending blades (or “wings”) 484 and 486 , respectively. This sheet 482 is preferably formed from a metal with a large elastic strain range such as spring steel or nickel titanium alloy. The sheet 482 can have a proximal end 488 and a distal end 490 . The distal end 490 can have a flat portion which can be flexible. A step portion 494 can be located between the distal end 490 and the proximal end 488 . The proximal end 488 can have a curved shape. The proximal end can also include blades 484 and 486 .
[0245] In the undeployed state depicted in FIGS. 60A and 60B , wings 484 and 486 are collapsed within outer cannula 470 while elongated sheet 482 is captured within deflecting passage or slot 474 . As the dissector component 480 is advanced into a disc 15 , passage or slot 478 directs the dissector component 480 in a direction roughly parallel to the posterior anulus (90 degrees to the central axis of sleeve 470 in this case) in a manner similar to that described for the embodiment in FIGS. 59A and 59B . Wings 484 and 486 open as they exit the end of sleeve 470 and expand toward the vertebral endplates. Further advancement of dissector component 480 allows the expanded wings 484 and 486 to dissect through any connections of nucleus 20 or anulus 10 to the endplates that may present an obstruction to subsequent passage of the implants of the present invention. When used to aid in the insertion of a barrier, the dimensions of dissector component 480 should approximate those of the barrier such that the minimal amount of tissue is disturbed while reducing the forces necessary to position the barrier in the desired location.
[0246] FIGS. 61A-61D illustrate a method of implanting a disc implant. A disc implant 552 is inserted into a delivery device 550 . The delivery device 550 has a proximal end 556 and a distal end 558 . The distal end 558 of the delivery device 550 is inserted into an annulotomy illustrated in FIG. 61A . The annulotomy is preferably located at a site within the anulus 10 that is proximate to a desired, final implant 552 location. The implant 400 is then deployed by being inserted into the disc 15 through the distal end 558 of the delivery device 550 . Preferably the implant is forced away from the final implant location, as shown in FIG. 61B . An implant guide 560 can be used to position the implant 400 . Before, during or after deployment of the implant 400 , an augmentation material 7 can be injected into the disc 15 . Injection of augmentation after deployment is illustrated in FIG. 61C . The augmentation material 7 can include a hydrogel or collagen, for example. In one embodiment, the delivery device 550 is removed from the disc 15 and a separate tube is inserted into the annulotomy to inject the flowable augmentation material 7 . Alternately, the distal end 558 of the delivery device 550 can remain within the annulotomy and the fluid augmentation material 554 injected through the delivery device 550 . Next, the delivery device 550 is removed from the annulotomy and the intradiscal implant 400 is positioned over the annulotomy in the final implant location, as shown in FIG. 61D . The implant 400 can be positioned using control filaments described above.
[0247] Certain embodiments, as shown in FIGS. 62-66 , depict anulus and nuclear augmentation devices which are capable of working in concert to restore the natural biomechanics of the disc. A disc environment with a degenerated or lesioned anulus cannot generally support the load transmission from either the native nucleus or from prosthetic augmentation. In many cases, nuclear augmentation materials 7 bulge through the anulus defects, extrude from the disc, or apply pathologically high load to damaged regions of the anulus. Accordingly, in one aspect of the current invention, damaged areas of the anulus are protected by shunting the load from the nucleus 20 or augmentation materials 7 to healthier portions of the anulus 10 or endplates. With the barrier-type anulus augmentation 12 in place, as embodied in various aspects of the present invention, nuclear augmentation materials 7 or devices can conform to healthy regions of the anulus 10 while the barrier 12 shields weaker regions of the anulus 10 . Indeed, the anulus augmentation devices 12 of several embodiments of the present invention are particularly advantageous because they enable the use of certain nuclear augmentation materials and devices 7 that may otherwise be undesirable in a disc with an injured anulus.
[0248] FIG. 62 is a cross-sectional transverse view of an anulus barrier device 12 implanted within a disc 15 along the inner surface of a lamella 16 . Implanted conformable nuclear augmentation 7 is also shown in contact with the barrier 12 . The barrier device 12 is juxtapositioned to the innermost lamella of the anulus. Conformable nuclear augmentation material 7 is inserted into the cavity which is closed by the barrier 12 , in an amount sufficient to fill the disc space in an unloaded supine position. As shown, in one embodiment, fluid nuclear augmentation 554 , such as hyaluronic acid, is used.
[0249] Fluid nuclear augmentation 554 is particularly well-suited for use in various aspects of the current invention because it can be delivered with minimal invasiveness and because it is able to flow into and fill minute voids of the intervertebral disc space. Fluid nuclear augmentation 554 is also uniquely suited for maintaining a pressurized environment that evenly transfers the force exerted by the endplates to the anulus augmentation device and/or the anulus. However, fluid nuclear augmentation materials 554 used alone may perform poorly in discs 15 with a degenerated anulus because the material can flow back out through anulus defects 8 and pose a risk to surrounding structures. This limitation is overcome by several embodiments of the current invention because the barrier 12 shunts the pressure caused by the fluid augmentation 554 away from the damaged anulus region 8 and toward healthier regions, thus restoring function to the disc 15 and reducing risk of the extrusion of nuclear augmentation materials 7 and fluid augmentation material 554 .
[0250] Exemplary fluid nuclear augmentation materials 554 include, but are not limited to, various pharmaceuticals (steroids, antibiotics, tissue necrosis factor alpha or its antagonists, analgesics); growth factors, genes or gene vectors in solution; biologic materials (hyaluronic acid, non-crosslinked collagen, fibrin, liquid fat or oils); synthetic polymers (polyethylene glycol, liquid silicones, synthetic oils); and saline. One skilled in the art will understand that any one of these materials may be used alone or that a combination of two or more of these materials may be used together to form the nuclear augmentation material.
[0251] Any of a variety of additional additives such as thickening agents, carriers, polymerization initiators or inhibitors may also be included, depending upon the desired infusion and long-term performance characteristics. In general, “fluid” is used herein to include any material which is sufficiently flowable at least during the infusion process, to be infused through an infusion lumen in the delivery device into the disc space. The augmentation material 554 may remain “fluid” after the infusion step, or may polymerize, cure, or otherwise harden to a less flowable or nonflowable state.
[0252] Additional additives and components of the nucleus augmentation material are recited below. In general, the nature of the material 554 may remain constant during the deployment and post-deployment stages or may change, from a first infusion state to a second, subsequent implanted state. For example, any of a variety of materials may desirably be infused using a carrier such as a solvent or fluid medium with a dispersion therein. The solvent or liquid carrier may be absorbed by the body or otherwise dissipate from the disc space post-implantation, leaving the nucleus augmentation material 554 behind. For example, any of a variety of the powders identified below may be carried using a fluid carrier. In addition, hydrogels or other materials may be implanted or deployed while in solution, with the solvent dissipating post-deployment to leave the hydrogel or other media behind. In this type of application, the disc space may be filled under higher than ultimately desired pressure, taking into account the absorption of a carrier volume. Additional specific materials and considerations are disclosed in greater detail below.
[0253] FIG. 63 is a cross-sectional transverse view of anulus barrier device 12 implanted within a disc 15 along an inner surface of a lamella 16 . Implanted nuclear augmentation 7 comprised of a hydrophilic flexible solid is also shown. Nuclear augmentation materials include, but are not limited to, liquids, gels, solids, gases or combinations thereof. Nuclear augmentation devices 7 may be formed from one or more materials, which are present in one or more phases. FIG. 63 shows a cylindrical flexible solid form of nuclear augmentation 7 . Preferably, this flexible solid is composed of a hydrogel, including, but not limited to, acrylonitrile, acrylic acid, polyacrylimide, acrylimide, acrylimidine, polyacrylonitrile, polyvinylalcohol, and the like.
[0254] FIG. 63 depicts nuclear augmentation 7 using a solid or gel composition. If required, these materials can be designed to be secured to surrounding tissues by mechanical means, such as glues, screws, and anchors, or by biological means, such as glues and in growth. Solid but deformable augmentation materials 7 may also be designed to resist axial compression by the endplates rather than flowing circumferentially outward toward the anulus. In this way, less force is directed at the anulus 10 . Solid nuclear augmentation 7 can also be sized substantially larger than the annulotomy 416 or defect 8 to decrease the risk of extrusion. The use of solid materials or devices 7 alone is subject to certain limitations. The delivery of solid materials 7 may require a large access hole 417 in the anulus 10 , thereby decreasing the integrity of the disc 15 and creating a significant risk for extrusion of either the augmentation material 7 or of natural nucleus 20 remaining within the disc 15 . Solid materials or devices 7 can also overload the endplates causing endplate subsidence or apply point loads to the anulus 10 from corners or edges that may cause pain or further deterioration of the anulus 10 . Several embodiments of the present invention overcome the limitations of solid materials and are particularly well-suited for use with liquid augmentation materials 7 . The barrier device 12 of various embodiments of this invention effectively closes the access hole 417 and can be adapted to partially encapsulate the augmented nucleus, thus mitigating the risks posed by solid materials.
[0255] Solid or gel nuclear augmentation materials 7 used in various embodiments of the current invention include single piece or multiple pieces. The solid materials 7 may be cube-like, spheroid, disc-like, ellipsoid, rhombohedral, cylindrical, or amorphous in shape. These materials 7 may be in woven or non-woven form. Other forms of solids including minute particles or even powder can be considered when used in combination with the barrier device. Candidate materials 7 include, but are not limited to: metals, such as titanium, stainless steels, nitinol, cobalt chrome; resorbable or non-resorbing synthetic polymers, such as polyurethane, polyester, PEEK, PET, FEP, PTFE, ePTFE, Teflon, PMMA, nylon, carbon fiber, Delrin, polyvinyl alcohol gels, polyglycolic acid, polyethylene glycol; silicon gel or rubber, vulcanized rubber or other elastomer; gas filled vesicles, biologic materials such as morselized or block bone, hydroxy apetite, cross-linked collagen, muscle tissue, fat, cellulose, keratin, cartilage, protein polymers, transplanted or bioengineered nucleus pulposus or anulus fibrosus; or various pharmacologically active agents in solid form. The solid or gel augmentation materials 7 may be rigid, wholly or partially flexible, elastic or viscoelastic in nature. The augmentation device or material 7 may be hydrophilic or hydrophobic. Hydrophilic materials, mimicking the physiology of the nucleus, may be delivered into the disc in a hydrated or dehydrated state. Biologic materials may be autologous, allograft, zenograft, or bioengineered.
[0256] In various embodiments of the present invention, the solid or gel nuclear augmentation material 7 , as depicted in FIG. 63 , are impregnated or coated with various compounds. Preferably, a biologically active compound is used. In one embodiment, one or more drug carriers are used to impregnate or coat the nuclear augmentation material 7 . Genetic vectors, naked genes or other therapeutic agents to renew growth, reduce pain, aid healing, and reduce infection may be delivered in this manner. Tissue in-growth, either fibrous (from the anulus) or bony (from the endplates), within or around the augmentation material can be either encouraged or discouraged depending on the augmentation used. Tissue in-growth may be beneficial for fixation and can be encouraged via porosity or surface chemistry. Surface in-growth or other methods of fixation of the augmentation material 7 can be encouraged on a single surface or aspect so as to not interfere with the normal range of motion of the spinal unit. In this way, the material is stabilized and safely contained within the anulus 10 without resulting in complete fixation which might cause fusion and prohibit disc function.
[0257] FIG. 64 is a cross-sectional transverse view of anulus barrier device 12 implanted within a disc 15 along an inner surface of a lamella 16 . Several types of implanted nuclear augmentation 7 , including a solid cube, a composite cylindrical solid 555 , and a free flowing liquid 554 are shown. The use of multiple types of nuclear augmentation with the barrier 12 is depicted in FIG. 64 . The barrier device 12 is shown in combination with fluid nuclear augmentation 554 , solid nuclear augmentation 7 , in the form of a cube, and a cross-linked collagen sponge composite 555 soaked in a growth factor. In several embodiments of the present invention, a multiphase augmentation system, as shown in FIG. 64 , is used. A combination of solids and liquids is used in a preferred embodiment. Nuclear augmentation 7 comprising solids and liquids 554 can be designed to create primary and secondary levels of flexibility within an intervertebral disc space. In use, the spine will flex easily at first as the intervertebral disc pressure increases and the liquids flows radially, loading the anulus. Then, as the disc height decreases and the endplates begin to contact the solid or gelatinous augmentation material, flexibility will decrease. This combination can also prevent damage to the anulus 10 under excessive loading as the solid augmentation 7 can be designed to resist further compression such that the fluid pressure on the anulus is limited. In a preferred embodiment, use of multiphase augmentation allows for the combination of fluid medications or biologically active substances with solid or gelatinous carriers. One example of such a preferable combination is a cross-linked collagen sponge 555 soaked in a growth factor or combination of growth factors in liquid suspension.
[0258] In one embodiment, the nuclear augmentation material or device 7 , 554 constructed therefrom is phase changing, e.g., from liquid to solid, solid to liquid, or liquid to gel. In situ polymerizing nuclear augmentation materials are well-known in the art and are described in U.S. Pat. No. 6,187,048, herein incorporated by reference. Phase changing augmentation preferably changes from a liquid to a solid or gel. Such materials may change phases in response to contact with air, increases or decreases in temperature, contact with biologic liquids or by the mixture of separate reactive constituents. These materials are advantageous because they can be delivered through a small hole in the anulus or down a tube or cannula placed percutaneously into the disc. Once the materials have solidified or gelled, they can exhibit the previously described advantages of a solid augmentation material. In a preferred embodiment, the barrier device is used to seal and pressurize a phase changing material to aid in its delivery by forcing it into the voids of the disc space while minimizing the risk of extrusion of the material while it is a fluid. In this situation, the barrier or anulus augmentation device 12 may be permanently implanted or used only temporarily until the desired phase change has occurred.
[0259] In another embodiment, an anulus augmentation device 12 that exploits the characteristics of nucleus augmentation devices or materials to improve its own performance is provided. Augmenting the nucleus 20 pressurizes the intervertebral disc environment which can serve to fix or stabilize an anulus repair device in place. The nucleus 20 can be pressurized by inserting into the disc 15 an adequate amount of augmentation material 7 , 554 . In use, the pressurized disc tissue and augmentation material 7 , 554 applies force on the inwardly facing surface of the anulus augmentation device 12 . This pressure may be exploited by the design of the anulus prosthesis or barrier 12 to prevent it from dislodging or moving from its intended position. One exemplary method is to design the inwardly facing surface of the anulus prosthesis 12 to expand upon the application of pressure. As the anulus prosthesis 12 expands, it becomes less likely to be expelled from the disc. The prosthesis 12 may be formed with a concavity facing inward to promote such expansion.
[0260] In several embodiments, the anulus augmentation device 12 itself functions as nuclear augmentation 7 . In a preferred embodiment, the barrier 12 frame is encapsulated in ePTFE. This construct typically displaces a volume of 0.6 cubic centimeters, although thicker coatings of ePTFE or like materials may be used to increase this volume to 3 cubic centimeters. Also, the anulus augmentation device may be designed with differentially thickened regions along its area.
[0261] FIG. 65 depicts a sagittal cross-sectional view of the barrier device connected to an inflatable nuclear augmentation device 455 . The barrier device 12 is shown connected via hollow delivery and support tube 425 to an nuclear augmentation sack 455 suitable for containing fluid material 554 . The tube 425 has a delivery port or valve 450 that extends through the barrier device and can be accessed from the access hole 417 after the barrier device 12 and augmentation sack 455 has been delivered. This nuclear and anulus augmentation combination is particularly advantageous because of the ease of deliverability, since the sack 455 and the barrier 12 are readily compressed. The connection of the barrier 12 and the augmentation sack 455 also serves to stabilize the combination and prevent its extrusion from the disc 15 . The nuclear augmentation 7 may be secured to the anulus augmentation prosthesis 12 to create a resistance to migration of the overall construct. Such attachment may also be performed to improve or direct the transfer of load from the nuclear prosthesis 7 through the anulus prosthesis 12 to the disc tissues. The barrier 12 and augmentation 7 can be attached prior to, during, or after delivery of the barrier 12 into the disc 15 . They may be secured to each other by an adhesive or by a flexible filament such as suture. Alternatively, the barrier 12 may have a surface facing the augmentation material 7 that bonds to the augmentation material 7 though a chemical reaction. This surface may additionally allow for a mechanical linkage to a surface of the augmentation material 7 . This linkage could be achieved through a porous attachment surface of the barrier 12 that allows the inflow of a fluid augmentation material 7 that hardens or gels after implantation.
[0262] Alternatively, the anulus augmentation device 12 and nuclear augmentation material 7 may be fabricated as a single device with a barrier 12 region and a nuclear augmentation region 7 . As an example, the barrier 12 may form at least a portion of the surface of an augmentation sack 455 or balloon. The sack 455 may be filled with suitable augmentation materials 7 once the barrier has been positioned along a weakened inner surface of the anulus 10 .
[0263] The sequence of inserting the barrier 12 and nuclear augmentation 7 in the disc can be varied according to the nuclear augmentation 7 used or requirements of the surgical procedure. For example, the nuclear augmentation 7 can be inserted first and then sealed in place by the barrier device 12 . Alternatively, the disc 15 can be partially filled, then sealed with the barrier device 12 , and then supplied with additional material 7 . In a preferred embodiment, the barrier device 12 is inserted into the disc 15 followed by the addition of nuclear augmentation material 7 through or around the barrier 12 . This allows for active pressurization. A disc 15 with a severely degenerated anulus can also be effectively treated in this manner.
[0264] In an alternative embodiment, the nuclear augmentation material 7 is delivered through a cannula inserted through an access hole 417 in the disc 15 formed pathologically, e.g. an anular defect 8 , or iatrogenically, e.g. an anuulotomy 416 that is distinct from the access hole 417 that was used to implant the barrier 12 . Also, the same or different surgical approach including transpsoas, presacral, transsacral, tranpedicular, translaminar, or anteriorly through the abdomen, may be used. Access hole 417 can be located anywhere along the anulus surface or even through the vertebral endplates.
[0265] In alternative embodiments, the anulus augmentation device 12 includes features that facilitate the introduction of augmentation materials 554 following placement. The augmentation delivery cannula may simply be forcibly driven into an access hole 417 proximal to the barrier 12 at a slight angle so that the edge of the barrier 12 deforms and allows passage into the disc space. Alternatively, a small, flexible or rigid curved delivery needle or tube may be inserted through an access hole 417 over (in the direction of the superior endplate) or under (in the direction of the inferior endplate) the barrier 12 or around an edge of the barrier 12 contiguous with the anulus 15 .
[0266] In several embodiments, ports or valves are installed in the barrier 12 device that permit the flow of augmentation material into, but not out of, the disc space. One-way valves 450 or even flaps of material held shut by the intervertebral pressure may be used. A collapsible tubular valve may be fashioned along a length of the barrier. In one embodiment, multiple valves or ports 450 are present along the device 12 to facilitate alignment with the access hole 417 and delivery of augmentation material. Flow channels within or on the barrier 12 to direct the delivery of the material 554 (e.g. to the ends of the barrier) can be machined, formed into or attached to the barrier 12 along its length. Alternatively, small delivery apertures (e.g. caused by a needle) can be sealed with a small amount of adhesive or sutured shut.
[0267] FIG. 66 is sagittal cross-sectional view of a functional spine unit containing the barrier device unit 12 connected to a wedge-shaped nuclear augmentation 7 device. FIG. 66 illustrates that the geometry of the nuclear augmentation 7 can be adapted to improve the function of the barrier. By presenting nuclear augmentation 7 with a wedge-shaped or hemicircular profile towards the interior of the intervertebral disc space, and attaching it in the middle of the barrier device 12 between the flexible finger-like edges of the barrier device, the force exerted by the pressurized environment is focused in the direction of the edges of the barrier device sealing them against the endplates. Accordingly, this wedge-shaped feature improves the function of the device 12 . One skilled in the art will understand that the nuclear augmentation material 7 may also be designed with various features that improve its interaction with the barrier, such as exhibiting different flexibility or viscosity throughout its volume. For example, in certain applications, it may be preferable for the augmentation 7 to be either stiff at the interface with the barrier 12 and supple towards the center of the disc, or vice versa. The augmentation 7 can also serve to rotationally stabilize the barrier 12 . In this embodiment, the augmentation is coupled to the inward facing surface of the barrier and extends outward and medially into the disc forming a lever arm and appearing as “T-shaped” unit. The augmentation device 7 of this embodiment can extend from the middle of the disc 15 to the opposite wall of the anulus.
[0268] In one embodiment, the anulus augmentation device comprises a mesh. FIG. 67 shows one example of a meshed anulus augmentation device. In one embodiment, a repair mesh that is resilient is provided. In some embodiments, the mesh is particularly advantageous because it can withstand millions of motion cycles within the disc environment, and is resistant to fatigue. In several embodiments, fatigue resistance is accomplished by material properties, structural design, or a combination thereof. For a given material, a fatigue resistant structure can be designed to distribute the strain of deformation as evenly as possible over as much material as possible so as to minimize stress concentrations that could initiate fatigue cracks. For example, a coiled spring may deform millions of times without failure or cracking because the strain is distributed evenly over a length of metal. For an anulus repair mesh, the same effect maybe achieved by means such as, but not limited to, providing more material for a given deformation site by having mesh members curved throughout their lengths, alternating mesh curves in a sine-wave or zigzag pattern to provide more material and distributed strains, or having longer non linear members such that a given deformation results in less material strain, or pre-shaping the implant to minimize strain at the implantation site. The curvilinear, nonlinear, coiled, or angled members can be interconnected, woven, networked, or emanate from or be attached to rails or members to form a framework or define a mesh or barrier.
[0269] In one embodiment, a mesh can be used in a variety of locations in and around the intervertebral disc. It can be placed on an external surface of the anulus, along an endplate, within the anulus, between the anulus and nucleus, within the nucleus, or within both the anulus and nucleus. The mesh can be held in place via counteracting forces of the mesh as it flexes from its unstressed shape to stressed shape or friction with disc tissue, between disc and vertebral body tissue or between disc augmentation material or another implant and disc tissue. The mesh can also have a porosity or macrotexture including ridges, spikes or spirals to increase bioincorporation and fixation. Fixation devices, including but not limited to, sutures, glue, screws, and staples can be used to permanently fix the mesh in place.
[0270] In one embodiment, the anulus augmentation device is a barrier comprising a membrane and a frame. In some embodiments, the frame is the mesh. In other embodiment, the mesh is coated with the membrane. In another embodiment, the anulus augmentation device comprises only a frame.
[0271] In one embodiment, the mesh or frame region of the implant can preferably be formed from a relatively thin sheet of material. The material may be a polymer (including in-situ polymerizing), metal, or gel. However, as discuss infra, the superelastic properties of nickel titanium alloy (NITINOL) makes this metal particularly advantageous in this application. Other materials suitable for this application include one or more of the following: nylon, polyvinyl alcohol, polyethylene, polyurethane, polypropylene, polycaprolactone, polyacrylate, ethylene-vinyl acetates, polystyrene, polyvinyl oxide, polyvinyl fluoride, polyvinyl imidazole, chlorosulphonated polyolefins, polyethylene oxide, polytetrafluoroethylene and nylon, and copolymers and combinations thereof, polycarbonate, Kevlar™, acetal, cobalt chrome, carbon, graphite, metal matrix composites, stainless steel and other metals, alloys and composites. Some materials may be coated to achieve biocompatibility. These materials can also be used for frames or support member that do not comprise meshes.
[0272] In some embodiments, the mesh or frame designs may have sharp edges or have gaps that may allow for tissue transfer outside of the disc. In one embodiment, a membrane may be secured to one or more sides or portions of the mesh or frame in order to resist transfer of particles across its periphery and outside of the disc or to shield the body from the mesh's sharp edges. Also, a membrane can prevent the flow of a material bounded by the anulus fibrosis of the intervertebral disc through a defect in the anulus fibrosis if the device is positioned across the defect.
[0273] In a preferred embodiment, the size of the mesh device is dictated by the particular region of the functional spinal unit sought to be treated. For example, In one embodiment, a mesh intended for coverage the interior surface of the posterior lateral anulus can be about 2 cm to about 4 cm in length and about 2 mm to about 15 mm in height. Likewise, the mesh can be sized to cover the entire exterior or interior surface of a disc. Also, if a defect or weakened segment of the disc is pre-opertively identified, the size of the mesh can be selected to adequately span it in more than one direction. In one embodiment, the mesh is sized such that it spans all directions by at least about 2 mm. The overlap provided by the about 2 mm or more mesh, in some embodiments, provides mechanical means by which the mesh resists extrusion through a defect. Where a case dictates that a device is not available for full coverage of a portion of the anulus, the surgeon can select a mesh, barrier, or patch that is sized such that even if the barrier shifts along an axis in either direction, the selected width ensures that there remains about 2 mm or more of the device beyond the edge of the defect in all positions along that portion of the anulus. In this way a surgeon can determine a minimum implant size that will still be efficacious.
[0274] In one embodiment, the anulus augmentation device, such as a mesh or a membrane/frame combination, has a thickness in a range between about 0.025 mm to about 3 mm. Nucleus pulposus particles have been measured at around 0.8 mm 2 . Accordingly, in one embodiment, the anulus augmentation device, such as a mesh or a membrane/frame combination, has pores slightly smaller (e.g., about 0.05 mm 2 to about 0.75 mm 2 ) and still function as a means to prevent extrusion of nuclear material from the disc. Alternatively, one of ordinary skill in the art can through experimentation determine the size of disc particles sought to be contained by the mesh and size the pores slightly smaller. Such a design affords the fluid transfer of other smaller particles and especially water, blood, and other tissue fluids.
[0275] In several embodiments, the cross-section of the mesh can be flat, concave, convex or hinged (or flexibly connected) along at least a portion of one or more horizontal axes or vertical axes. One of skill in the art will understand that other cross-sections can also be used in accordance with several embodiments of the invention.
[0276] It has been determined that in procedures wherein only a limited amount of nucleus or anulus tissue is removed from a pathologic disc, approximately 0.2 to about 2.0 cc of tissue is typically removed. Accordingly, to replace this volume loss and contribute to the biomechanical function of the spine, spinal implants can be designed to replace this volume (about 0.2 to 2.0 cc) through selection of materials and their dimensions. Accordingly, in one embodiment, an implant having a volume of about 0.2 to about 2.0 cc is provided. The implant can include an anulus augmentation device, a nuclear augmentation device or an anulus augmentation/nuclear augmentation combination device. Preferably, a device having an overall volume of about 0.5 cc is provided because this is the most typical volume removed. Also, greater volumes may be used to further increase the volume of the disc in cases where disc height has decreased over time and the fragments have been metabolized (and thus do not require removal).
[0277] In one embodiment, an implant comprising a frame and a membrane is provided. In other embodiments, the implant comprises only one or more membranes. In one embodiment, the implant comprises only one or more frames. The frame may be coated. The membrane (or coating) can be comprised of any suitably durable and flexible material including polymers, elastomers, hydrogels and gels such as polyvinyl alcohol, polyethylene, polyurethane, polypropylene, polycaprolactone, polyacrylate, ethylene-vinyl acetates, polystyrene, polyvinyl oxides, polyvinyl fluorides, polyvinyl imidazole, chlorosulphonated polyolefin, polyethylene oxide, polytetrafluoroethylene, a nylon, silicone, rubber, polylactide, polyglycolic acid, polylactide-co-glycolide, polycaprolactone, polycarbonate, polyamide, polyanhydride, polyamino acid, polyortho ester, polyacetal, polycyanoacrylate, degradable polyurethane, copolymers and derivatives and combinations thereof. Biological materials including keratin, albumin collagen, elastin, prolamines, engineered protein polymers, and derivatives and combinations thereof, may also be used.
[0278] In one embodiment, at least a portion of the anulus augmentation device (e.g., the membrane, mesh, barrier, etc,) can be impregnated with, coated with, or designed to carry and deliver diagnostic agents and/or therapeutic agents. Diagnostic agents include, but are not limited to, radio-opaque materials suitable to permit imaging by MRI or X-ray. Therapeutic agents include, but are not limited to, steroids, genetic vectors, antibodies, antiseptics, growth factors such as somatomedins, insulin-like growth factors, fibroblast growth factors, bone morphogenic growth factors, endothelial growth factors, transforming growth factors, platelet derived growth factors, hepatocytic growth factors, keratinocyte growth factors, angiogenic factors, immune system suppressors, antibiotics, living cells such as fibroblasts, chondrocytes, chondroblasts, osteocytes, mesenchymal cells, epithelial cells, and endothelial cells, and cell-binding proteins and peptides. In other embodiments, the nuclear augmentation device can be impregnated, coated, or designed to carry diagnostic and/or therapeutic agents.
[0279] In one embodiment, as shown in FIG. 67 , a mesh having a series of curvilinear elements 602 is provided. In one embodiment, the curvilinear elements 602 are interconnected. One of skill in the art will understand that the curvilinear elements 602 can exist independently of each other, or only be partially connected. The interconnections 602 can be distributed to form one or more contiguous horizontal bands, rails, members, struts, or axes 604 . FIG. 67 shows such a device with a central horizontal axis 604 and “S” shaped curvilinear elements 602 . In one embodiment, the “S” shaped elements 602 tend to distribute the stress generated under compression over a larger area. In one embodiment, only portions of the “S” move out of plane during loading providing stiffness. In some embodiments, the curvilinear elements are particularly advantageous because they provide flexibility, resilience and/or rigidity.
[0280] In some embodiments, the curvilinear elements 602 can be oriented about 90 degrees (curving in the ventral/dorsal axis) such that the curves appear in the overall horizontal cross-section of the implant. In other embodiments, the curvilinear elements 602 are substantially flat. The curvilinear elements 602 can also be oriented at any angle (e.g., from about 1 degree to about 179 degrees) from the plane. The mesh 600 can be straight, convex or concave in cross-section. FIGS. 68 A-G show the profile of a mesh with various curvilinear elements. FIGS. 68 D-G show top cross-sectional views of the mesh being elongated “U” shaped, “C” shaped, curvilinear shaped (like a typical posterior anulus interior surface), and “D” shaped to extend along and cover the entire inner anulus surface.
[0281] FIG. 69 shows yet another embodiment of a mesh 600 implanted in an intervertebral disc. Here, the curvilinear elements 602 comprise springs, coils, or telescopic members that are adapted to compress axially (like pneumatic pistons or coil springs) under loading rather than bending and conforming to a tissue surface, e.g. the inner surface of the anulus. One advantage of a spring or coil-type mesh is that the mesh can be fairly rigid and resistant to lateral or transverse force but is flexible enough to span around the curvatures of the disc while maintaining contact with the endplates under compression and expansion. Like other curvilinear elements, the springs or coils can be interconnected, linked in a loose or hinge-like arrangement, attached to a horizontal band or axis, attached to a membrane, or encapsulated within a membrane, or portions thereof.
[0282] In one embodiment, the mesh may also be configured (e.g., from wire or stock) in a pattern comprising a series of repeating curved peaks and valleys oriented in a lateral manner. Two or more curved wires may be superimposed out of phase such that one peak is inferior to the adjacent wires valley. The two wires can be independent, contiguous and formed from a single wire, connected at one or more points, attached to a membrane, or encapsulated within a membrane. FIG. 70 shows a wire-type anulus augmentation device.
[0283] As discussed above, an annulus augmentation device can comprise, for example, a frame, a membrane or a frame/membrane combination. FIG. 70 shows just the frame, which can be, for example, a wire or mesh-like device. FIGS. 71 A-E show a mesh that has been encapsulated by a membrane or cover to produce an encapsulated mesh 606 . FIGS. 71C shows a top view cross-section wherein the mesh is elongated U shaped and 71 D through 71 F show various side view cross-sections wherein the mesh is straight or possesses varying degrees of concavity. As with other barriers disclosed herein, the membrane or encapsulation material may be of substantial thickness or may be substantially thin. Indeed, the encapsulation material may simply be a coating.
[0284] In another embodiment, as shown in FIGS. 72 A-B, a mesh 600 having a double-wishbone frame with or without membrane cover is provided. In some embodiments, this design is particularly advantageous because it reduces the compression and stress experienced by the implant under flexion, extension, and lateral bending. FIG. 72A shows the frame without a membrane situated along a posterior portion of the disc. The implant (e.g., the frame) can also be placed on the outside of the anulus, within the anulus, between the nucleus and anulus or within the nucleus. Also shown is a defect 16 in the anulus 10 and placement of the frame 600 across the defect and spanning beyond it in more than a single direction. FIG. 72B shows the mesh in a perspective view outside of the disc. The frame (e.g., mesh) can be flat or an elongated “U” shaped corresponding to the inner surface of the posterior anulus. In one embodiment, the frame can be a single continuous band or wire forming two ends, a first end and a second end. In one embodiment, each end functions as a living hinge and forms an apex which may be in the form of a curve, a bend, or series of bends such that the wire is generally redirected in the opposite direction. Accordingly, if a load is applied along the vertical axis at the midpoint of the frame, e.g., the midpoint of the top and bottom (superior, inferior) rail, each corner or apex is loaded equally and the wire rails act as levers.
[0285] In one embodiment, the mesh 600 can be implanted such that the midpoint of the mesh frame 600 is in the posterior of the disc and the ends reside medially or even in the anterior portion of the disc. In this way the portion of the mesh 600 that undergoes the greatest compression is furthest away from each end. Accordingly, a relatively large range of motion can be traversed by the middle of the device but this will only translate to limited motion at each end or living hinge, thus reducing stress and fatigue. Also, by placing each end (which has a relatively small profile) at opposing sides at the midline of the disc (the center of rotation) it is subjected to almost no direct loading under lateral bending, flexion, extension, or compression by the endplates.
[0286] FIGS. 73 A-C shows other embodiments for the end or natural hinge portion of the frame (e.g., mesh 600 ), including a loop formation.
[0287] FIGS. 74 A-C show some embodiments of the central band or strut 604 . FIGS. 74 A-B show a central reinforcement band 604 disposed between the ends or apexes of the frame (e.g., mesh). As shown in FIG. 74B , the central band 604 can be positioned between the top rail (or wire) 603 and bottom rail (or wire) 605 . As shown in FIG. 74C , the central band 604 can be elongated to form a concave cross-section between the top and bottom rail or wire.
[0288] In several embodiments of the invention, an implant (e.g., an anulus augmentation device, such as a mesh) can exhibit different mechanical properties along various axes. For example, an implant can exhibit rigidity along a first axis and flexibility (or less rigidity) along a second axis transverse or perpendicular to the first. Such an implant might find particular utility along the wall of an anulus between two adjacent vertebrae because such an environment will subject the implant to vertical compression (e.g., along the superior/inferior axis) yet will not compress the implant laterally. As such, the implant can retain its rigidity along its horizontal axis. Rigidity along the horizontal axis of anulus augmentation device is especially useful in some embodiments if the implant is placed in front of a weakened or defective surface of the anulus because a point load will like form at that region when the disc is compressed under loading and could cause the implant to bend and extrude. Accordingly, an implant having a certain degree of rigidity along its lateral axis resists such bending and extrusion. Moreover, because of the less rigid and more flexible behavior of the implant along its vertical axis loads caused flexion and extension of the spine will allow the implant to flex naturally with the spine and not injure the endplates.
[0289] In some embodiments, to achieve the differences in mechanical properties, any number of construction, material selection or fabrication techniques known in the art can be used. For example, the implant may be made thicker or thinner at points along a particular axis or voids or patterns may be cut into the material. Also, a composite implant having different material sandwiched together can also be used. Struts, members, rails and the like may be added to, secured to, or integral to the implant to provide stiffness and rigidity. Further, such stiffening elements can be added during the implantation procedure.
[0290] In one embodiment, the implant can also be corrugated along an axis or otherwise be provided with bents or curves to provide stiffness. A gentle curve or “C” shaped cross-section that could also conform or correspond to the inner curved surface of an anulus is also preferable for making a seal with the anulus and for resisting bending along the implant horizontal axis e.g., the curve would resist flattening out, flexing or bending laterally. Also, in some embodiments the implant can be oversized such that it remains in compression along one or more of its axes in its implanted state such that even under flexion and extension of the spine the corrugations or curved sections never flatten out and thus retain rigidity (or less flexibility) along an axis perpendicular to the curves.
[0291] One of skill in the art will understand that, in several embodiments, the implant (e.g., an anulus augmentation device, such as a mesh) can be more or less rigid or flexible, according to the preference of the practitioner or disc environment. The degree of desired rigidity and flexibility along each axis can be determined based on factors such as defect size, intervertebral pressure, implant deliverability, desired degree of compression and disc height.
[0292] According to one embodiment of the invention, an implant has a “C” cross-section, a central rail and top and bottom rails, and curvilinear elements connect the rails. The frame or mesh can be comprised of any of the suitable materials discussed herein, (e.g. nickel titanium) and can also be coated, covered, bonded, or coupled to a cover or membrane. In one embodiment, the implant is more rigid along its lateral axis because of its “C” cross-section or the rails and less rigid along its vertical axis because of the void caused by the pattern and lack of corrugations or stiffening elements.
[0293] Though some embodiments of the invention disclose a mesh frame, patch, plate, biocompatible support member or barrier adapted to extend along the inner circumference of an anulus fibrosus, other embodiments contemplate partial coverage of the anulus or tissue surface. For some embodiments that that cover less than the entire inner surface of the anulus or that are not fully anchored in place, and are susceptible to migration, one or more projections extending outward from, or off-angle to the implant can be configured to resist migration or movement of the implant within the disc under cyclical loading and movement of the spine. One advantage of such embodiments is that they can reduce or prevent migration. Undesired migration may render the implant ineffective or cause it to pathologically interfere with adjacent tissue including the anulus, nucleus, endplates and spinal cord.
[0294] According to one embodiment, an implant can be stabilized within an intervertebral disc by providing a support member or patch with an off-angle projection functioning as a lever arm or keel. In some embodiments, even a slightly angled projection (e.g., about 5 to about 10 degrees) can serve to reduce the tendency of the device to rotate or migrate if it has sufficient surface area and length (about 3 mm to about 30 mm). As shown previously in FIGS. 25 and 34 , one embodiment of an anulus augmentation device can have one or more corners, sides or projections connected at the opposing end of the devices midsection or middle portion. Such a configuration is especially effective when implanted into an intervertebral disc such that the midsection of the barrier is inserted along the posterior anulus and the corners and side projections are inserted along the posterio-lateral corners and lateral anulus respectively. In one embodiment, the corner sections extend away from the posterior anulus toward the anterior of the disc. The projections that project away from the posterior anulus at an angle (about 90 degrees or through a radius of curvature resulting in an angle from about 30 to about 150 degrees) are substantially parallel with or adjacent to the lateral anulus. Thus, the projection portion of the implant in its implanted orientation is at once off-angle to the posterior anulus or midsection of the barrier and parallel to the lateral anulus. Because the anulus defines a bounded area such a projection may indeed collide with or be parallel with another adjacent or opposing surface of the anulus but still function to stabilize the device along the other surface. The device can also be designed with one or more projections that are angled toward the medial, anterior, posterior, or lateral portion of the disc such that the projection contacts mostly or exclusively nucleus tissue or endplate. For example, a looped projection connected at the top and bottom and/or opposing ends of the support member, frame, or patch can be configured to extend across the disc from about 3 mm to about 30 mm and only contact nucleus tissue. In another embodiment, one or more projections can be oriented into a defect in the anulus and occupy less than or all of its volume. In another embodiment, a projection situated within a defect may be anchored into an endplate adjacent the defect. FIGS. 75 A-L show an implant 610 (e.g., an annulus augmentation device such as a mesh) having one or more projections extending into the disc or into a defect.
[0295] A stabilizing projection according to one or more embodiments of the invention can be integral or affixed to the surgical mesh, patch, plate, biocompatible support member or barrier device. The stabilizing projection can also be independent of or coupled to at least a portion of the frame or the membrane. The stabilizing projection can be constructed from the same material as the frame or the membrane, or it can be constructed from different material. The stabilizing projection can extend from any point or points along the device or device frame including its opposing ends, mid-section, along the top edge or along the bottom edge. The projection can also form a loop in one or more planes including parallel and perpendicular to the face of the device. For example, in one embodiment opposing end projections are connected to, or are integral to, the barrier and extend out from the barrier at an angle from about 0 to about 160 degrees. In another embodiment, the projections are joined or are simply contiguous and form a bow-shaped or curved projection extending away from the barrier. In this embodiment, the barrier can be placed along a portion of the anulus and the bow would extend medially into the disc. In another embodiment, the barrier can be placed along at least a portion of the posterior anulus and the bowed projection, attached at the opposing ends of the barrier frame or membrane, would extend toward the anterior of the disc.
[0296] FIG. 76 shows an implant 610 according to one embodiment of the invention. Here, a bow-like anterior projection 612 extends outwardly from a posterior support member 614 (e.g., a patch, barrier or mesh). The projection 612 can be connected at each end of the posterior support member 614 along its horizontal axis. The projection 612 can be attached at any point along the vertical axis of the end including its midline, ends, or its entirety. The projection 612 may be integral to the posterior support member 614 such that the posterior support member 614 is simply formed as a band or attached separately. As shown the implant 610 can be shaped like a bow. The bow can be a gentle arc, curved, re-curved one or more times, triangular, rectangular, octagonal, linked multiple sided, oval or circular. Though in some embodiments, an arc or smooth bow may be advantageous for transferring loads evenly, a rigid mid-section portion or a comparatively flexible hinge-like mid-section along the bow is also presented. The mid-section of the bow projection can have a different height than the remainder of the bow and be the same or different (less than or greater than) height than the midsection patch or biocompatible support member portion of the device.
[0297] Various embodiments of the bow or arcurate member or projection 612 can act like a spring to aid in holding the ends of the patch open and against the anulus wall. Similarly, in one embodiment, the profile of the projection 612 can provide resistance to anterior travel of the implant through the nucleus or through the opposite wall of the anulus. In another embodiment of the invention, the projection or stabilizer 612 can also provide torsional resistance to the barrier 614 . Finally, because the projection or bow 612 extends across the endplates it creates an elongated profile functioning as a lever arm and thus resists rotation along the anulus wall within the disc.
[0298] The projection, bow or band portion 612 of the implant 610 can be tubular, wire-like, flat, mesh-like, curvilinear, bent, comprised of one or more rails, or contain voids. The bow can define concavities facing inward or outward and be opposite or the same as the concavities defined by the biocompatible support member portion 614 of the implant 610 . The projection 612 can simply be angled projections of the biocompatible support member and be made of the same material and have the same properties. Alternatively the projection can have different properties such as less flexibility or more rigidity along one or more axes. Although one projection is shown in FIG. 76 , more than one bow-like projections may be used.
[0299] Different bow or loop projection profiles may be useful for retaining nucleus tissue within the area bounded by the implant, soft anchoring to the nucleus or at least resisting travel through or along the nucleus, or for mechanically displacing nucleus tissue. Mechanical displacement (through pinching or pressing) of the nucleus can increase disc height and serve to more uniformly load the anulus and improve the performance of the implant. Also, the gap within the disc created by the bow or projection can be left vacant or filled in with suitable nucleus augmentation either through, or around a periphery of the implant. The bow projection 612 can also act as a piston or shock absorber that deforms under compressive loading of the disc relieving some of the load on the anulus caused by the nucleus being compressed between the endplates.
[0300] The stabilizing projection 612 can be made of the same material as the biocompatible support member 614 (e.g., barrier, patch or mesh). In one embodiment, the stabilizing projection 612 is an off-angle projection of the biocompatible support member 614 and forms a continuous loop or band. In another embodiment, the stabilizing projection 612 can be made of a different biocompatible material, including polymers, metals, bio-materials, and grafts.
[0301] FIGS. 77 A-H show various cross-sectional side views of an implant 610 along a horizontal axis according to one or more embodiments of the invention. Accordingly, a bow, band or projection can be uniform in height or non-uniform. It can be the same height, shorter or taller than the patch portion of the implant. For example, in one embodiment, a projection is narrow at the point where it connects to the posterior support member component of the implant and then flairs near the midline of the anterior bow until its height exceeds the posterior member height. Such a configuration might be favorable between cupped or concave vertebral endplates when the posterior member portion of the implant is positioned against the posterior anulus. Further, in one or more embodiments of the invention, a projection can have different mechanical properties than the support member or patch section of the implant. For example, in one embodiment, a projection is more or less flexible along one or more axes compared to the patch or biocompatible support member portion of the implant. In another embodiments, a projection can be concave along one or more axes, or can have variable regions of concavity along the same axis.
[0302] FIGS. 78 A-J show various cross-sectional top views of implants 610 along a vertical axis according to some embodiments of the invention. For example, FIG. 78G shows an implant (e.g., an anulus augmentation device such as a mesh) that has a puckered bow-like projection that is well-suited for disc morphology.
[0303] FIGS. 79 A-F show a frontal view of a portion of various embodiments of projections according to one or more embodiments of the invention.
[0304] FIGS. 80 A-D show various cross-sections of projection 612 , according to some embodiments of the invention.
[0305] FIGS. 81 A-D show looped or bent bow-type projections 612 that are contiguous or integral with, or are connected to the biocompatible support member 614 at two or more points along a vertical or horizontal axis. FIG. 81A shows a criss-cross loop projection. FIG. 81B shows a strap-like projection. FIG. 81C shows a projection that is integral with the support member such that the implant forms a circular band that serves to stabilize the device. FIG. 81D shows a box-frame type projection.
[0306] One skilled in the art will appreciate that any of the above procedures involving nuclear augmentation and/or anulus augmentation may be performed with or without the removal of any or all of the autologous nucleus. Further, the nuclear augmentation materials and/or the anulus augmentation device may be designed to be safely and efficiently removed from the intervertebral disc in the event they are no longer required.
[0307] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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Resilient surgical meshes that, in some aspects, can be compressed or otherwise configured, for minimally invasive delivery in the intervertebral discs are provided. According to one or more embodiments, the surgical mesh can be robust, fatigue resistant, stable and capable of withstanding the dynamic environment generic to intervertebral discs.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of valves used to control the flow of fluids. More specifically, the invention comprises an interlocking control handle which can be employed as a safety device for preventing a child from actuating a gas or water valve.
2. Description of the Related Art
Conventional water faucets feature control valves which a user can rotate to actuate water flow. Various control schemes are used in the prior art for control of water flow from a faucet. One common scheme employs two control valves, where one control valve regulates the volumetric flow rate of water from a hot stream and a second control valve regulates the volumetric flow rate of water from a cold stream. In this control scheme the hot water stream and cold water stream mix before the water is discharged from the faucet. A second common control scheme involves a single control valve which regulates the temperature of the water discharged from the faucet. In this scheme a single valve regulates the ratio of hot water volume to cold water volume. Sometimes an additional control valve is provided to control the overall flow rate of water through the faucet.
These conventional flow control valves are generally easy to operate as only a small amount of torque or rotational force is required to turn the valve. This can present a hazardous condition for a small child who is left unsupervised around a bath tub or shower. Incidents of drowning or scalding are not uncommon since most parents cannot always be aware of what their children are doing.
Although many inventors have sought to make a child-proof control valve, many of these devices have presented their own drawbacks. One problem with many of these prior art devices is that many adults find the devices too cumbersome to use. It is therefore desirable to provide a new control valve that is both child-proof and comfortable for adults to use.
BRIEF SUMMARY OF THE INVENTION
The present invention is an interlocking control valve which can be used to control the flow of fluids such as water and gas. The control valve features a push button on the end of a handle which permits the interlocking valve to engage the valve stem when the push button is pressed. A fixed washer is provided with a hole-and-groove cutout, thereby preventing rotation of the handle with respect to the washer unless the push button is pressed.
The invention provides all of these features, advantages, and objects along with others that will become apparent with reference to the following description and accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view, showing the external components of the present invention.
FIG. 2 is a cut-away view, showing the internal components of the present invention.
FIG. 3 is an exploded view, showing the fixed washer.
FIG. 4A is a top view, showing an embodiment of the fixed washer.
FIG. 4B is a top view, showing an embodiment of the fixed washer.
FIG. 4C is a top view, showing an embodiment of the fixed washer.
FIG. 5A is a cross-section view, showing the present invention in the locked position.
FIG. 5B is a cross-section view, showing the present invention in the unlocked position.
REFERENCE NUMERALS IN THE DRAWINGS
10
interlocking controller
12
push button
14
mount shaft
16
handle
18
valve stem
20
spring
22
button shaft
24
spring bracket
26
fixed washer
28
button stem
34
cutout
36
key
38
mount plate
40
slit
42
screw holes
44
groove
46
hole
48
mounting surface
50
notches
52
detachable end
54
valve stem keyway
56
valve stem receiver
58
screw hole
60
tightening screw
DETAILED DESCRIPTION OF THE INVENTION
The external features of the present invention are shown in FIG. 1 . Interlocking controller 10 is provided for control of fluid flow through a valve. Interlocking controller 10 is mounted to a valve stem (not shown) protruding from mounting surface 48 . Mounting surface 48 in customary applications is usually a shower wall or counter top. The controller is generally composed of handle 16 , mount shaft 14 , fixed washer 26 , and mount plate 38 . Handle 16 is illustrated as a simple bar-type handle but can be any shape conducive to gripping. Push button 12 is positioned on one side of handle 16 . The reader will note that bar-type handle design and location of push button 12 provides a comfortable gripping surface as the user is able to position their thumb over push button 12 and wrap the other four fingers around handle 16 .
The internal components of the interlocking control handle are shown in FIG. 2 . A preferred embodiment of the interlocking controller has detachable end 52 at the end of handle 16 opposite push button 12 . Detachable end 52 is made detachable to facilitate the assembly of the internal components of the handle. Button shaft 22 is spring-biased to bear against push button 12 . Spring 20 and spring bracket 24 are provided to supply resistance to the movement of push button 12 in the direction of detachable end 52 . The force supplied by the spring is ideally adapted so that a young child would be unable to press push button 12 into handle 16 . The resistive force is ideally limited, however, to that which can be overcome by the normal hand strength of an older child or adult.
Push button 12 is seated within a bore in handle 16 in such a manner that it is free to move a fixed distance within the handle. Accordingly, push button 12 can be positioned in either the pushed position or the unpushed position.
Button stem 28 is attached in substantially perpendicular relation to button shaft 22 . A preferred embodiment of the invention utilizes a threaded attachment of the button stem 28 to button shaft 22 for simpler manufacture and assembly. In this version, button stem 28 has a threaded shank (not shown) which can be threadedly connected to a threaded bore on button shaft 22 . The attachment means could just as easily be reversed in that button stem 28 could have a threaded bore and button shaft 22 could have a threaded shank.
The interlocking controller is also provided with valve stem receiver 56 which functions to connect the controller to valve stem 18 . Valve stem 18 passes through mount plate 38 and through fixed washer 26 and is finally received within valve stem receiver 56 . Various mechanism can be used to connect fixed valve stem 18 to valve stem receiver 56 . A simple means to attach valve stem 18 to valve stem receiver 56 and mount shaft 14 of handle 16 is illustrated in FIG. 2 . Screw hole 58 is provided in mount shaft 14 for receiving tightening screw 60 . When valve stem 18 is inserted into valve stem receiver 56 , the installer can screw in tightening screw 60 , thereby preventing the accidental detachment of handle 16 from valve stem 18 .
The reader will note that button stem 28 also passes through fixed washer 26 . This feature causes the handle to be locked when the push button is in the unpushed position and unlocked when the push button is in the pushed position as will be explained subsequently.
FIG. 3 illustrates the attachment of fixed washer 26 and mount plate 38 . Fixed washer 26 has cutout 34 and key 36 . Mount plate 38 is placed over valve stem 18 and can be attached to the mounting surface by screwing mount plate 38 to the mounting surface through screw holes 42 . Slit 40 is also provided for receiving key 36 of fixed washer 26 when it is placed over valve stem 18 . Multiple slits 40 can be placed around mount plate 38 (in a circle) and multiple keys 36 can be placed around the lower perimeter of fixed washer 26 to ensure that the orientation of cutout 34 does not accidentally change with respect to mount plate 38 when the handle is turned. The use of multiple slits and multiple keys also allows the installer to finely adjust the orientation of fixed washer 34 so that the locked position of the handle corresponds with the off position of the valve.
Several versions of fixed washers are illustrated in FIGS. 4A , 4 B, and 4 C. FIG. 4A shows the top of fixed washer 26 with cutout 34 which is comprised of hole 46 and groove 44 . As explained above, fixed washer 26 is adapted so that it does not move relative to mount plate 38 and mounting surface 48 . Groove 44 is adapted to receive button stem 28 when push button 12 is in the unpushed position. Hole 46 is large enough to receive button stem 28 and mount shaft stem 32 when the push button 12 is in the pushed position, thereby allowing the two components to be rotated within hole 46 when handle 16 is turned. Because of the shape of cutout 34 and the stationary nature of fixed washer 26 , handle 12 cannot turn when push button 12 is in the unpushed position and button stem 28 is positioned in groove 44 .
FIG. 4B shows another version of fixed washer 26 and cutout 34 . In this version, groove 44 and hole 46 appear more distinct, unlike the fixed washer in FIG. 4A which smoothly contours the two components together.
A third version of the fixed washer is shown in FIG. 4C . This version features notches 50 in hole 46 . Notches 50 allow the valve to be locked in various incremental positions. This feature not only prevents a small child from turning on the water faucet but also prevents them from adjusting the temperature once it has been set.
FIGS. 5A and 5B illustrate cross-sectional views the internal components of the interlocking controller when the push button is in the unpushed position and the pushed position. The cross-sections are observed directly above the top of fixed washer 26 and directly below the bottom of mount shaft 14 . Push button 12 is shown in the unpushed position in FIG. 5A . The reader will observe the relationship between push button 12 and the position of button stem 28 with respect to cutout 34 and button stem groove 30 . When in the unpushed positing button stem 28 is seated in groove 44 of fixed washer 26 . Valve stem 18 is seated in hole 46 , but because of the shape of cutout 34 and the location of button stem 28 within groove 44 , handle 16 will not turn.
FIG. 5B illustrates the internal components of the interlocking controller assembly when push button 12 is in the pushed position and the handle is slightly turned. As shown in FIG. 5B cutout 34 does not restrict the movement of handle 16 when push button 12 is in the pushed position. Button stem 28 mates against the outside of valve stem receiver 56 when the push button is pushed. Accordingly, the space between button stem 28 and valve stem 18 represents the width of valve stem receiver 56 . The reader will observe that button stem 28 and valve stem 18 jointly occupy hole 46 thereby permitting the handle to be turned.
The reader will appreciate that in each of the above mentioned embodiments of the present invention, the restricting means (such as cutout 34 and other components of the invention responsible for restricting the movement of interlocking controller 10 ) are substantially enveloped by interlocking controller 10 . This feature prevents the critical moving parts responsible for restricting the movement of interlocking controller 10 from being exposed to the environment and the user, thereby preventing injury to the user and damage to interlocking controller 10 .
The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. As an example, many variations of hole 46 and groove 44 can be utilized for cutout 34 , and notches 50 can be included an any of these variations. Such a variation would not alter the function of the invention. In addition, many shapes could be used for the handle without departing from the spirit and scope of the present invention. Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.
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An interlocking control valve which can be used to control the flow of fluids such as water and gas. The control valve features a push button on the end of a handle which permits the interlocking valve to engage the valve stem when the push button is pressed. A fixed washer is provided with a hole-and-groove cutout, thereby preventing rotation of the handle with respect to the washer unless the push button is pressed.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/454,803, filed Mar. 21, 2011, titled AN APPARATUS AND METHOD OF SUPPORTING AND POWERING A MONITOR MOUNTED TO A MULTI-FLOOR PIPE APPARATUS, docket ELK01-P-351, the disclosure of which is expressly incorporated by reference.
TECHNICAL FIELD
[0002] The present invention generally relates to an apparatus for supporting and delivering power to a monitor, which is mounted to the outlet end of a multi-floor pipe apparatus and, further, to a frame to support the multi-floor pipe apparatus.
BACKGROUND
[0003] As described in U.S. Pat. No. 7,299,883, it is often difficult to extinguish fires in a multi-floor building where one or more floors in which the fire is located are inaccessible due to excessive heat or due to compromised flooring. To address this problem, the '883 patent describes a pipe apparatus that is supported on a frame, which allows the outlet end of the pipe apparatus to be extended through an opening in the building, such as a window, and then raised so that the outlet end of the pipe apparatus can direct water to a floor above where the frame is located.
SUMMARY
[0004] In an exemplary embodiment of the present disclosure, a fire fighting system for use in a multi-story building is provided. The fire fighting system including a pipe apparatus having an inlet and an outlet, the inlet for coupling to a supply of fire fighting fluid, and the outlet for directing the fire fighting fluid; a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to the supply of fire fighting fluid at a first floor of the building and enabling the outlet to deliver fluid to a higher floor of the building relative to the first floor; an electrically controlled fluid delivery device mounted at said outlet and in fluid communication with the pipe apparatus; and a power supply having a power source, said power source being located remotely from the electrically controlled fluid delivery device and supported by the frame assembly and is proximate to the inlet of the pipe apparatus. In an example thereof, the power source is operatively coupled to the electrically controlled fluid delivery device to control an operation of the electrically controlled fluid delivery device. In another example thereof, the fire fighting system further comprises at least one electrical cord which operatively couples the power source to the electrically controlled fluid delivery device. In a variation thereof, the fire fighting system further comprises an extension arm coupled to the pipe apparatus, the extension arm including a conduit through which the at least one electrical cord passes. The pipe apparatus may include a first portion and a second portion which telescopes relative to the first portion resulting in the outlet being moveable relative to the input and the extension arm includes a telescoping portion. The conduit extending through the telescoping portion resulting in the at least one electrical cord passing through the telescoping portion. In another variation thereof, the fire fighting system further comprises an extension arm coupled to the pipe apparatus, the extension arm including a telescoping portion, and the at least one electrical cord passing through a conduit mounted to the telescoping portion. In a further example, the pipe apparatus is moveable relative to the frame assembly. In a variation thereof, the fire fighting system further comprises a plurality of bearings carried by the pipe apparatus which are received by a plurality of tracks carried by a plurality of guide members of the frame assembly, the plurality of bearings being located proximate a bend in the pipe apparatus. In a further variation thereof, the frame assembly further includes a pivot structure which is engaged by the bearings at a terminal end of the plurality of tracks such that when the plurality of bearings engage a portion of the pivot structure the pipe apparatus pivots relative to the frame assembly resulting in the outlet of the pipe apparatus being raised relative to the frame assembly. In still a further variation thereof, the pivot structure includes a lower ramped surface for guiding the plurality of bearings carried by the pipe apparatus and a generally vertically oriented portion which meets the lower ramped portion at a transition, the transition being the portion of the pivot structure. In another variation, the plurality of guide members and the pivot structure are steel metal components coupled together. In yet another example, a plurality of tips extend downward from the frame assembly, the plurality of tips being configured to reduce slippage of the frame assembly relative to a floor of the building. In still another example, the fire fighting system further comprises wheels which support the frame assembly, the wheels being moveable relative to the frame assembly between a deployed position and a stowed position. In yet still another example, the pipe apparatus is moveable relative to the frame assembly and the power supply is carried by the pipe apparatus. In a variation thereof, the fire fighting system further comprises an extension arm coupled to the pipe apparatus, wherein the pipe apparatus includes a first portion and a second portion which telescopes relative to the first portion resulting in the outlet being moveable relative to the input and the extension arm includes a telescoping portion, the power supply being carried by the extension arm. In a variation thereof, the power supply includes a housing including at least one electrical connector which are operatively coupled to the at least one electrical cord, the at least one electrical cord operatively coupling the power supply to the electrically controlled fluid delivery device. In a further variation thereof, the power source includes at least one electrical connector, the at least one electrical connector of the power source aligns with the at least one electrical connector of the housing. In still a further variation thereof, the housing includes an open end to receive the power source and an opening opposite the open end.
[0005] In another exemplary embodiment of the present disclosure, a method of fighting a fire in a multi-story building is provided. The method comprising the steps of supporting a fire fighting system at a first floor of the multi-story building; positioning an electronically controlled fluid delivery device proximate an exterior of the multi-story building at an opening in the exterior of the multi-story building corresponding to a second floor of the multi-story building; positioning a portable power source of the electronically controlled fluid delivery device below the second floor of the multi-story building, the second floor being above the first floor; and delivering a fire fighting fluid from an interior of the first floor of the multi-story building to the exterior of the building and then to the second floor of the multi-story building through the opening in the exterior of the multi-story building corresponding to the second floor of the multi-story building with the fire fighting system and the electronically controlled fluid delivery device. In an example thereof, the method further comprises the steps of providing a frame assembly supported by the first floor of the multi-story building; moveably coupling a pipe apparatus to the frame assembly, the pipe assembly being pivotable relative to the frame assembly to extend from the first floor of the multi-story building to the second floor of the multi-story building; and supporting the power source on the pipe assembly.
[0006] In a further exemplary embodiment of the present disclosure, a system for use in a multi-story building is provided. The system including a pipe apparatus having an inlet and an outlet, the inlet for coupling to a supply of fluid, and the outlet for directing the fluid; a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to the supply of fluid at a first floor of the building and enabling the outlet to deliver fluid to a higher floor of the building relative to the first floor; an electrically controlled fluid delivery device mounted at said outlet and in fluid communication with the pipe apparatus; and a power supply having a power source, said power source being located remotely from the electrically controlled fluid delivery device and supported by the frame assembly and is proximate to the inlet of the pipe apparatus. In one example, the power source is operatively coupled to the electrically controlled fluid delivery device to control an operation of the electrically controlled fluid delivery device. In another example, the system further comprises at least one electrical cord which operatively couples the power source to the electrically controlled fluid delivery device; and an extension arm coupled to the pipe apparatus, the extension arm including a conduit through which the at least one electrical cord passes, wherein the pipe apparatus includes a first portion and a second portion which telescopes relative to the first portion resulting in the outlet being moveable relative to the input and the extension arm includes a telescoping portion.
[0007] In still a further exemplary embodiment of the present disclosure, a method of providing a fluid in a multi-story building is provided. The method comprising the steps of supporting a system at a first floor of the multi-story building; positioning an electronically controlled fluid delivery device proximate an exterior of the multi-story building at an opening in the exterior of the multi-story building corresponding to a second floor of the multi-story building; positioning a portable power source of the electronically controlled fluid delivery device below the second floor of the multi-story building, the second floor being above the first floor; and delivering a fluid from an interior of the first floor of the multi-story building to the exterior of the building and then to the second floor of the multi-story building through the opening in the exterior of the multi-story building corresponding to the second floor of the multi-story building with the system and the electronically controlled fluid delivery device. In an example thereof, the method further comprises the steps of providing a frame assembly supported by the first floor of the multi-story building; moveably coupling a pipe apparatus to the frame assembly, the pipe assembly being pivotable relative to the frame assembly to extend from the first floor of the multi-story building to the second floor of the multi-story building; and supporting the power source on the pipe assembly.
[0008] The present disclosure provides a fire fighting system, which includes a pipe apparatus, a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to a supply of fire fighting fluid at a first floor of a building and enabling the outlet to deliver fluid to another location at a different floor than the first floor, and an electrically controlled fluid delivery device mounted at the outlet of the pipe apparatus. A power supply is provided that includes a power source operable to power the electrically controlled fluid delivery device, with power source located remotely from the electrically controlled fluid delivery device so that it is at or in close proximity to the inlet end of the pipe apparatus.
[0009] The frame assembly may be assembly from one or more metal blanks to provide a light weight frame that improves the portability of the system.
[0010] These and other objects, advantages, purposes, and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side elevation view of a multi-floor pipe apparatus and support frame therefor;
[0012] FIG. 2 is a side elevation view of the multi-floor pipe apparatus of FIG. 1 , which incorporates a power supply system;
[0013] FIG. 3 is a similar view to FIG. 2 illustrating the pipe apparatus in an extended configuration;
[0014] FIG. 4 is a fragmentary enlarged cross-sectional view of the extension arm of the pipe apparatus forming a passageway for the power supply cable;
[0015] FIG. 5 is an exploded perspective view of the power supply system housing and battery;
[0016] FIG. 6 is an exploded perspective view of the frame of another embodiment of the support frame for the pipe apparatus;
[0017] FIG. 7 is a side elevation view of a frame with a retractable wheel in a deployed position;
[0018] FIG. 8 is a similar view to FIG. 7 illustrating the retractable wheel in a retracted position;
[0019] FIG. 9 is a representative view of the multi-floor pipe apparatus and support frame of FIG. 1 and a multi-story building.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The embodiments disclosed herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. While the present disclosure primarily involves the delivery of a fire fighting fluid to combat fires, it should be understood, that the invention may have application to other scenarios. In one embodiment, the systems and methods disclosed herein may be implemented to provide a fluid for neutralizing one or more chemical substances. For example, the systems and methods disclosed herein may be used to neutralize or otherwise alter chemicals used in explosives, drugs, or other items. Further, the systems and methods disclosed herein may be implemented to immobilize individuals.
[0021] Referring to FIGS. 1-3 , the numeral 10 generally designates a multi-floor firefighting system, which is adapted to direct the flow of water from one floor of a building to another floor of the building, as will be more fully described below. Multi-floor firefighting system 10 includes a multi-floor pipe apparatus 12 and a frame assembly 14 . Frame assembly 14 supports pipe apparatus 12 and forms a guide for the pipe apparatus 12 and so that the pipe apparatus may be supported while it is pushed, for example to the right as viewed in FIG. 1 , and guided so that the outlet end 16 of pipe apparatus 12 can be extended through an opening in the building, for example through a window, and then raised to direct firefighting fluid to the floor above. To increase the range of pipe apparatus 12 , pipe apparatus 12 includes a telescoping portion that is extendible using an extendible arm 18 . For further details of pipe apparatus 12 , frame 14 , and extension arm 18 , reference is made to U.S. Pat. No. 7,299,883 and pending U.S. application Ser. No. 12/099,247 entitled APPARATUS AND METHOD FOR EXTINGUISHING FIRES IN A MULTI-FLOORED BUILDING, which are hereby incorporated in their entireties.
[0022] In order to increase the range, direction and/or control of the flow of firefighting fluid from the outlet end 16 of pipe apparatus 12 , an electronically controlled fluid delivery device 30 may be mounted to the outlet end 16 of pipe apparatus 12 . Exemplary electronically controlled fluid delivery devices include a nozzle or a monitor and nozzle. A monitor may increase the reach of the fluid flowing through pipe apparatus 12 and, further, provides enhanced control over the direction of flow from the outlet. Suitable nozzles and monitors are sold by Elkhart Brass Manufacturing Company, Inc. (Elkhart Brass) of Elkhart, Ind., with suitable monitors sold under the trademarks STINGER™ and SIDEWINDER® EXM available from Elkhart Brass. Exemplary electronically controlled monitors are disclosed in U.S. patent application Ser. No. 12/174,866, titled FIREFIGHTING DEVICE FEEDBACK CONTROL, the disclosure of which is expressly incorporated by reference herein.
[0023] In order to operate the power-operated actuators, such as motors 32 , on the nozzle and/or monitor, power must be supplied to the actuator(s) 32 and control unit 34 . However, locating a power supply at the nozzle or monitor potentially exposes the power source of the power supply to excessive heat and other detrimental environments and increases the effort to extend the pipe apparatus. Accordingly, the present invention provides a power supply system, illustratively a battery 20 that can deliver power to the monitor without subjecting the source of the power supply to the same environment as the monitor and/or nozzle and, moreover, that is accessible to the firefighter without putting the firefighter to greater risk of injury. For ease of description, the description hereafter references a monitor and nozzle application, but the invention is not so limited and also includes just the use of a nozzle or other fluid delivery devices. The illustrated battery 20 is an example of a portable power supply.
[0024] As shown in FIG. 9 , multi-floor firefighting system 10 is shown with frame assembly 14 mounted to a window sill 200 A of a building 202 . Window sill 200 A is part of a floor 204 A of building 202 while a window sill 200 B is part of a floor 204 B of building 202 . As illustrated in FIG. 9 , floor 204 B is positioned above floor 204 A. In one embodiment, at least one additional floor is provided between floor 204 A and floor 204 B. In one embodiment, floor 204 A and floor 204 B are both above a ground floor level of building 202 . Pipe apparatus 12 of multi-floor firefighting system 10 extends through an opening 206 A of floor 204 A of building 202 and electronically controlled fluid delivery device 30 is positioned adjacent an opening 206 B of floor 204 B of building 202 . A supply of fire fighting fluid, illustratively a water source 210 , is coupled to inlet 24 of pipe apparatus 12 . Other fire suppression agents may be used instead of water.
[0025] Water source 210 provides water to pipe apparatus 12 which travels through pipe section 12 A generally in direction 212 . The water then travels upward in generally direction 214 and exits monitor 30 which is in fluid communication with the pipe apparatus 12 generally in direction 216 to combat a fire on floor 204 B. An operator through control unit 34 may control motors 32 to adjust a nozzle of electronically controlled fluid delivery device 30 or to change an orientation of electronically controlled fluid delivery device 30 to direct the water in various directions. In one embodiment, an operator provides input signals to control unit 34 through a control input device 37 . The control input device 37 may be a portable handheld device or attached to frame assembly 14 . In one embodiment, the control input device 37 communicates with the control unit 34 over a wired connection. In one embodiment, the control input device 37 communicates with the control unit 34 over a wireless connection.
[0026] Referring to FIGS. 2 and 3 , the power supply system includes a battery 20 and a housing 22 , which is mounted to the extension arm 18 and which holds battery 20 . In the illustrated embodiment, housing 22 is supported on the fixed end of the extension arm 18 A adjacent its connection to inlet pipe section 12 A, which forms inlet end 24 of pipe apparatus 12 .
[0027] As described in the referenced application, pipe apparatus 12 has a curvilinear structure, which forms inlet 24 for receiving a fluid from a source of fluid pressure, and an intermediate portion 12 B, which is located between the inlet 24 and outlet 16 and which is adapted to extend from a lower floor to an upper floor. Pipe apparatus 12 is formed from a rigid material, such as a metal material, including steel, stainless steel, or aluminum or an alloy thereof, but may also be produced from a polymeric material, such as polyvinyl chloride. Pipe apparatus 12 is generally formed from several pipe sections, which are joined end to end and, further as described, includes an extendible intermediate portion that includes a telescoping portion 12 C, so that the length of the pipe apparatus 12 may be increased to extend the position of outlet 16 .
[0028] Referring to FIGS. 1-3 , as noted, pipe apparatus 12 also includes an extendible arm 18 with one end attached adjacent outlet 16 and the other end attached to inlet pipe section 12 A. In addition to providing stiffness to pipe apparatus 12 , extendible arm 18 retains the pipe apparatus in its desired length and, further, supports the telescoping portion 12 C when it is extended.
[0029] As previously noted, frame 14 is adapted to support pipe apparatus 12 in a manner so that pipe apparatus 12 may be laterally guided and, further, may be pivoted to allow the outlet of the pipe apparatus to initially be extended through an opening in the wall of the building, for example through a window, and then raised so that it extends up to the floor above. As best seen in FIGS. 2 and 3 , mounted to either side of the pipe apparatus is a pair of bearings, such as rollers 40 , which are guided along tracks formed by a pair of rails in frame assembly 14 . Rollers 40 are guided along the tracks to a terminal end of the tracks where continued forward movement of the pipe apparatus translates the motion into pivoting of the pipe apparatus to thereby raise the outlet 16 . To facilitate the movement of the pipe apparatus along frame assembly 14 , extension arm 18 includes a pair of transverse bars 42 , which may be used as handles to push the pipe apparatus along the guide tracks provided by the rails.
[0030] To accommodate the extension of the pipe apparatus 12 , extension arm 18 includes a fixed tubular member 18 A and a telescoping tubular member 18 B, which can be fixed in position along member 18 A to fix the length of intermediate pipe section 12 B by pins 44 , which extend through transverse openings provided in tubular members 18 A and 18 B. As previously noted, battery housing 22 is mounted to fixed tubular member 18 A and further remote from outlet 16 . In order to accommodate the extension of extension arm 18 (and the extension of the monitor mounted to outlet 16 ), the electrical cord that provides the connection between battery 20 and the monitor and nozzle motors may comprise a coiled electrical cord 44 . Cord 44 may be routed through a conduit 46 , which may be mounted to telescoping tubular member 18 B or as noted below through extension arm 18 .
[0031] Housing 22 may be fixedly mounted to tubular member 18 A by a bracket 22 A or may be movably mounted to tubular member 18 A by a sleeve, such as a sleeve with low friction liner to allow movement of housing 22 along tubular member 18 B when a sufficient force is applied. As best seen in FIGS. 2 and 3 , housing 22 is mounted near or adjacent the proximal end of tubular member 18 A to facilitate replacement of the battery when apparatus 12 is in use. When located at the proximal end of tubular member 18 a , the housing and battery are either in the building or at least easily accessible from the building even when pipe apparatus 12 is extended from the building.
[0032] Referring to FIG. 4 alternately coiled electrical cord 44 may be extended through extension arm 18 . The extension arm provides protection from the harsh environment and protection to the cable.
[0033] Referring to FIG. 5 , battery housing 22 optionally incorporates one or more electrical connectors 48 . Connectors 48 couple to the electrical cord (or cords) 44 and which correspond to and align with corresponding connectors 50 provided on battery 20 so that when battery 20 is inserted in housing 22 , connectors 50 will mate with and connect to connectors 48 to provide automatic electrical connection of the battery to the power cord. Furthermore, connections 48 and 50 are configured to provide mechanical or frictional coupling between the respective connectors to retain the battery 20 in housing 22 when inserted.
[0034] In the illustrated embodiment, housing 22 includes an opening 52 on one end of the housing, which includes a recess 54 that extends into the side of housing 22 . Positioned below recess 54 and mounted to the exterior surface 22 A of housing 22 are connectors 48 . Battery 20 similarly includes surface mounted connectors 50 , which align with recess 54 when inserted into housing 22 so that connectors 50 can be aligned with and guided into connection with connectors 48 . Furthermore, housing 22 is sized so that when battery 20 is inserted into housing, the upper end 56 of battery 20 is substantially flush with the end of housing 22 . Optionally, the battery may incorporate a handle or an engagement structure to facilitate removal of the battery from the housing. Alternately, as shown, the battery may be ejected from the housing by way of an opening 58 provided at the opposed end of the housing, such as shown in FIG. 5 . Opening 58 is sized large enough to allow a gloved hand to extend into the housing and push battery 20 from the opposed opening 52 . When mounted to extension arm 18 , the opening 58 , for example may be oriented toward the inlet pipe section 12 A to provide easy access to a firefighter.
[0035] As would be understood, by locating the battery at the proximal end of extension arm 18 , the battery is located below and away from the high heat area when apparatus 10 is deployed in a firefighting situation. Furthermore, the location provides a firefighter easier access to the battery and reduces the force required to raise the pipe apparatus.
[0036] Referring to FIG. 6 , the numeral 114 generally designates a multi-floor pipe apparatus support frame assembly. In one embodiment, frame assembly 114 is formed from a plurality of metal sheets that are stamped into a blank and assembled together, by a combination of folding portions of the blank and then securing some of them in place, by welding, bolting or riveting, to simplify the frame assembly and, further, to optionally reduce the weight of the frame assembly and increase the manufacturability. In one embodiment, additional non-sheet metal components may form part of frame assembly 114 . It should be understood that apparatus 10 is often carried by one or more firefighters to a location in a building, which may require them to maneuver up several flights of stairs; therefore, weight is a significant consideration for such firefighting equipment.
[0037] As best seen in FIG. 6 , frame assembly 114 includes a pair of rollers or bearing guides 116 and 118 , a pivot structure 120 , which joins guides 116 and 118 on one end, and a retaining member 122 , which joins the other ends of guides 116 and 118 to form a frame. Retaining member 122 includes an opening 124 to form an entryway for the bearings or rollers ( 40 ) on pipe apparatus 12 into the guide tracks 116 A and 118 A formed by the guides 116 and 118 . Pivot structure 120 provides a pivot surface for the rollers and a terminal end of the tracks so that when rollers reach pivot structure 120 , forward motion of pipe apparatus 112 will be translated into pivoting and raising of the outlet 16 .
[0038] Each of the respective components 116 , 118 , 120 , and 122 are stamped or otherwise cut from a sheet of metal, including aluminum or other metal sheet stock, which are then folded into the configurations as shown in FIG. 6 . For example, the guide members 116 and 118 are folded into a channel-shaped configuration to form tracks 116 A, 118 A with a pair of upwardly and downwardly extending flanges 126 and 128 , which may form additional guide surfaces for the pipe apparatus as it is moved along the guide path formed by guide tracks 116 A and 118 A. Cut out from the channel-shaped section at the pivot end of the frame are flanges 130 and 132 , which include mounting openings 130 A, 132 A for receiving shafts of wheels or rollers or brackets such as described in reference to FIGS. 7 and 8 . Optional additional intermediate cut-outs 134 and 136 may be provided in the web 140 of the channel-shaped section to provide mounting structures for anchoring stabilizing structure, such as described in U.S. Pat. No. 7,299,883 and pending U.S. application Ser. No. 12/099,247 entitled APPARATUS AND METHOD FOR EXTINGUISHING FIRES IN A MULTI-FLOORED BUILDING, which are hereby incorporated herein in their entireties, to anchor frame assembly 114 to the floor of a building. Further, additional cut-outs may be made to reduce the weight of frame assembly 114 .
[0039] Pivot guide structure 120 is cut and folded together as shown in FIG. 6 to form a lower channel-shaped section 142 , which is sized and arranged to join with the respective ends of the guide members 116 and 118 . Lower channel-shaped section 142 forms a ramped surface 144 for guiding the rollers and, hence the pipe apparatus 12 , upwardly until the rollers reach the transition 146 between the lower ramped surface 142 and the generally vertically oriented portion 148 of guide 120 . Once the rollers reach transition 146 , the intermediate pipe section 18 will pivot about rollers to raise the outlet of the pipe, which is guided through upper channel shaped member 150 . As noted, the respective components of the frame assembly may be bolted together, riveted together, or welded and, further, may be reinforced using conventional techniques.
[0040] Referring to FIGS. 7 and 8 , as previously noted, the frame assembly ( 114 or 14 ) may incorporate bearings, such as wheels 60 , to facilitate the transportation of system 10 . Further, wheels 60 may be provided that are retractable. In the illustrated embodiment, wheels 60 may be mounted to the frame assembly ( 114 or 14 ) by a generally L-shaped bracket 62 , which is pinned on one leg by a pin 64 to frame assembly, and supports a shaft 66 of wheel 60 at its other leg 62 B. When deployed, the wheels are generally located beneath the frame assembly ( 114 or 14 ) for engaging the ground or floor, but then can be pivoted along an accurate path about pins 64 to a stowed position to prevent the frame from moving when in use. For example, pins 64 may incorporate torsion control mechanisms, which limit free movement of the bracket 62 about pins 64 but allow rotation of the bracket when a sufficient force is applied.
[0041] To reduce slippage of the frame assembly ( 114 or 14 ), the frame assembly may incorporate pointed tips 68 , which are mounted to the underside of the frame assembly that engage the floor or surface on which the apparatus is located. For example, suitable tips include carbide tips, which can extend through carpet or other floor coverings to engage the concrete or subfloor to prevent slippage of the frame assembly relative to the floor (or to a ground surface).
[0042] While several forms of the invention have been shown and described, other changes and modifications will be appreciated by those skilled in the relevant art. Therefore, it will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention which is defined by the claims which follow as interpreted under the principles of patent law including the doctrine of equivalents.
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A system for use in a multi-story building is provided. The system may include a pipe apparatus having an inlet and an outlet. The inlet is coupled to a supply of fluid and the outlet directs the fluid. The system may include a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to the supply of fluid at a first floor of the building and enabling the outlet to deliver fluid to a higher floor of the building relative to the first floor. The system may include an electrically controlled fluid delivery device mounted at said outlet and in fluid communication with the pipe apparatus. The system may include a power supply having a power source located remotely from said electrically controlled fluid delivery device and supported by the frame assembly.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a film forming liquid composition. The liquid composition includes a film forming polymer, a low boiling point solvent, and a high boiling point solvent. Active ingredients, such as anti-itch actives, cooling actives, antibiotics, and the like are included in the compositions. The compositions are applied to the skin and the low boiling point solvent evaporates, leaving a polymeric film on the skin. The film which is left on the skin is plasticized by the high boiling point solvent included in the liquid composition. The polymeric film delivers the active ingredients to the skin over time.
[0003] 2. Description of the Prior Art
[0004] Minor cuts and scrapes, sunburn, bug bites, and poison ivy are conditions that cause discomfort for many consumers. These conditions frequently cause the skin to feel itchy. Consumers tend to scratch the itch. Scratching the itchy area can result in further damage to the skin, including infection. Therefore, health care professionals recommend keeping the affected area clean and dry.
[0005] Many anti-itch products are commercially available. The anti-itch products that are commercially available tend to be in the form of liquid sprays or lotions that are sprayed onto or rubbed into the affected area of the skin. The liquid sprays tend to have a viscosity similar to that of water. This means that the liquid tends to spread too easily, can drip off the skin onto which it has been sprayed, and can be messy with respect to articles of clothing.
[0006] The commercially available anti-itch lotions tend to be much more viscous than the liquid sprays. The lotions may be difficult to pour and to spread on the skin.
[0007] Frequently, the lotions are pink, due to the color of the active ingredient present therein. This can be unsightly, as the area of skin where the lotion is applied becomes pink. The pink color is also problematic for staining articles of clothing.
[0008] Gel compositions have been developed for treating sunburn and the itch associated with poison ivy. These gel compositions utilize clays to form the gel. The gels tend to be highly viscous. The high viscosity is desirable, as it prevents the composition from running or dripping. The gels are typically sold in squeeze tubes.
[0009] Although liquid anti-itch products are effective, consumers frequently scratch the area of the skin to which the anti-itch product has been applied. It would be advantageous to provide a composition that provides a barrier, which discourages the consumer from scratching the affected area of skin and delivers active ingredients to the skin.
[0010] A product sold under the designation “New Skin” has been commercially available for quite some time. This product contains nitrocellulose in acetone. The product is used to cover damaged skin. It is quite common to see a bowler develop a blister on the thumb used for bowling. The “New Skin” product is frequently applied to the affected area to protect the skin from further damage. Alternatively, the “New Skin” product may be applied to the skin to prevent damage in the first instance. The “New Skin” composition does not contain an active ingredient or a plasticizer.
[0011] There is a continuing need for a composition that provides a barrier to scratching the skin and delivers active ingredients to the skin.
SUMMARY OF THE INVENTION
[0012] In accordance with one aspect of the present invention, there is provided a film forming liquid composition for use in delivering actives to skin and protecting the skin. The liquid composition includes a film forming polymer; a low boiling point solvent; a high boiling point solvent, and at least one active ingredient.
[0013] In a second embodiment, the present invention provides a method for protecting skin and delivering at least one active ingredient to the skin including applying composition having a film forming polymer; a low boiling point solvent; a high boiling point solvent, and at least one active ingredient to the damaged skin.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] The compositions of the present invention include a film forming polymer. The film forming polymer is suitable for contact with damaged skin. Suitable film forming polymers include, but are not limited to, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and ethylene vinyl acetate. Copolymers and blends of polymers may also be used in the practice of the present invention. Cellulose acetate butyrate is the presently preferred film-forming material. The amount of film forming polymer utilized in the compositions of the present invention may range from about 3 percent to about 15 percent, preferably from about 3 percent to about 10 percent by weight, based on the total weight of the composition.
[0015] The compositions of the present invention also include a low boiling point solvent. Suitable low boiling point solvents have boiling points below about 100° F. Suitable low boiling point solvents include, but are not limited to, n-hexane, n-heptane, n-octane, cyclohexane, cyclopentane, methanol, ethanol, n-propanol, isopropanol, n-butyl alcohol, methyl ethyl ketone, ethyl acetate, and acetone. Ethyl acetate is preferred as the low boiling point solvent. The amount of low boiling point solvent in the compositions of the present invention may range from about 70 percent to about 95 percent, preferably from about 75 percent to about 95 percent by weight, based on the total weight of the composition.
[0016] A high boiling point solvent is included in the compositions of the present invention to plasticize the film forming polymer. Suitable high boiling point solvents have boiling points above about 100° F. Suitable high boiling point solvents include, but are not limited to, triacetin, tributyrin, triethyl citrate, and combinations thereof. The amount of high boiling point solvent may range from about 1 percent to about 10 percent by weight, preferably from about 1 percent to about 5 percent by weight, based on the total weight of the composition.
[0017] The compositions of the present invention include at least one active ingredient for delivery to skin. Typical actives include pain relief active ingredients; itch relief active ingredients; antibiotics; antifungal agents; antihistamine agents; anti-inflammatory agents; antipruritic agents; skin and mucous membrane agents; wound care agents; and combinations thereof. Specific active ingredients include, but are not limited to, benzocaine, menthol, camphor, and diphenhydramine. Menthol, camphor, benzocaine, and combinations thereof are preferred. As is known in the art, the amount of active ingredient may vary, depending on the desired effect. Generally, the total amount of active ingredient may range from about 0.05% to about 30% by weight, based on the total weight of the composition.
[0018] The compositions of the present invention are prepared by admixing the ingredients in a suitable vessel and stirring the mixture. The compositions are applied to the affected area of the skin. The low boiling point solvent evaporates, leaving the plasticized polymer in film form on the skin. The active ingredient is released from the film over time and is thereby delivered to the skin.
[0019] Several examples are described below to illustrate the present invention. The invention should not be construed as being limited to the details thereof.
EXAMPLE 1
[0020] The following materials were combined in a vessel:
[0021] 149.64 g ethyl acetate (low boiling point solvent),
[0022] 20 g cellulose acetate butyrate (film forming polymer), and
[0023] 20 g triacetin (high boiling point solvent).
[0024] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredients were then added with continued stirring:
[0025] 10 g benzocaine (topical anesthetic),
[0026] 0.18 g menthol, and
[0027] 0.18 g camphor.
[0028] The solution was stirred until it became clear again. The composition contained 10% cellulose acetate butyrate, 0.09% menthol, 0.09% camphor, 10% triacetin, 5% benzocaine, and 74.82% ethyl acetate.
EXAMPLE 2
[0029] The following materials were combined in a vessel:
[0030] 149.64 g ethyl acetate (low boiling point solvent),
[0031] 20 g cellulose acetate butyrate (film forming polymer), and
[0032] 20 g tributyrin (high boiling point solvent).
[0033] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredients were then added with continued stirring:
[0034] 10 g benzocaine,
[0035] 0.18 g menthol, and
[0036] 0.18 g camphor.
[0037] The solution was stirred until it became clear again. The composition contained 10% cellulose acetate butyrate, 0.09% menthol, 0.09% camphor, 10% tributyrin, 5% benzocaine, and 74.82% ethyl acetate.
EXAMPLE 3
[0038] The following materials were combined in a vessel:
[0039] 149.64 g ethyl acetate (low boiling point solvent),
[0040] 20 g cellulose acetate butyrate (film forming polymer), and
[0041] 20 g Triethyl citrate (high boiling point solvent).
[0042] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredients were then added with continued stirring:
[0043] 10 g benzocaine,
[0044] 0.18 g menthol, and
[0045] 0.18 g camphor.
[0046] The solution was stirred until it became clear again. The composition contained 10% cellulose acetate butyrate, 0.09% menthol, 0.09% camphor, 10% Triethyl citrate, 5% benzocaine, and 74.82% ethyl acetate.
EXAMPLE 4
[0047] The following materials were combined in a vessel:
[0048] 186 g ethyl acetate (low boiling point solvent),
[0049] 10 g cellulose acetate butyrate (film forming polymer), and
[0050] 3.8 g triacetin.
[0051] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0052] 0.2 g camphor.
[0053] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 0.1% camphor, 1.9% triacetin, and 93% ethyl acetate.
EXAMPLE 5
[0054] The following materials were combined in a vessel:
[0055] 186 g ethyl acetate (low boiling point solvent),
[0056] 10 g cellulose acetate butyrate (film forming polymer), and
[0057] 3.8 g triacetin.
[0058] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0059] 0.2 g menthol.
[0060] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 0.1% menthol, 1.9% triacetin, and 93% ethyl acetate.
EXAMPLE 6
[0061] The following materials were combined in a vessel:
[0062] 185 g ethyl acetate (low boiling point solvent),
[0063] 10 g cellulose acetate butyrate (film forming polymer), and
[0064] 4 g triacetin.
[0065] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0066] 1 g camphor.
[0067] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 0.5% camphor, 2% triacetin, and 92.5% ethyl acetate.
EXAMPLE 7
[0068] The following materials were combined in a vessel:
[0069] 185 g ethyl acetate (low boiling point solvent),
[0070] 10 g cellulose acetate butyrate (film forming polymer), and
[0071] 4 g triacetin.
[0072] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0073] 1 g menthol.
[0074] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 0.5% menthol, 2% triacetin, and 92.5% ethyl acetate.
EXAMPLE 8
[0075] The following materials were combined in a vessel:
[0076] 181 g ethyl acetate (low boiling point solvent),
[0077] 12 g cellulose acetate butyrate (film forming polymer), and
[0078] 6 g triacetin.
[0079] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0080] 1 g menthol.
[0081] The solution was stirred until it became clear again. The composition contained 6% cellulose acetate butyrate, 0.5% menthol, 3% triacetin, and 90.5% ethyl acetate.
EXAMPLE 9
[0082] The following materials were combined in a vessel:
[0083] 185 g ethyl acetate (low boiling point solvent),
[0084] 10 g cellulose acetate butyrate (film forming polymer), and
[0085] 4 g tributyrin.
[0086] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0087] 1 g menthol.
[0088] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 0.5% menthol, 2% tributyrin, and 92.5% ethyl acetate.
EXAMPLE 10
[0089] The following materials were combined in a vessel:
[0090] 180.2 g ethyl acetate (low boiling point solvent),
[0091] 12 g cellulose acetate butyrate (film forming polymer), and
[0092] 6 g tributyrin.
[0093] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0094] 1.8 g menthol.
[0095] The solution was stirred until it became clear again. The composition contained 6% cellulose acetate butyrate, 0.9% menthol, 3% tributyrin, and 90.1% ethyl acetate.
EXAMPLE 11
[0096] The following materials were combined in a vessel:
[0097] 180.2 g ethyl acetate (low boiling point solvent),
[0098] 10 g cellulose acetate butyrate (film forming polymer), and
[0099] 4 g triethyl citrate.
[0100] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0101] 1.8 g menthol.
[0102] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 0.9% menthol, 2% triethyl citrate, and 90.1% ethyl acetate.
EXAMPLE 12
[0103] The following materials were combined in a vessel:
[0104] 182 g ethyl acetate (low boiling point solvent),
[0105] 10 g cellulose acetate butyrate (film forming polymer), and
[0106] 6 g triacetin.
[0107] The solution was stirred until the polymer was dissolved and the solution became clear. The following ingredient was then added with continued stirring:
[0108] 2 g camphor.
[0109] The solution was stirred until it became clear again. The composition contained 5% cellulose acetate butyrate, 1% camphor, 3% triacetin, and 91% ethyl acetate.
[0110] In the foregoing Examples, benzocaine functions as a topical anesthetic; and camphor and methol function as anti-itch agents.
[0111] The compositions of Examples 1-12 above were tested by brushing approximately one ml of each composition on the skin of a finger to cover approximately a 1 cm×2.5 cm area of skin. The compositions were evaluated for drying time, water resistance, and film quality.
[0112] The compositions all dried within 1 minute and formed clear, almost invisible films. The polymer film coated fingers were placed under hot (approximately 50° C.) and cold (approximately 25° C.) water running from a tap. The polymer films were water resistant and adhered to the skin even under the running water. The polymer films had very little tack, and therefore did not pick up any dirt. The films adhered well to the skin for more than eight hours with excellent bioadhesion (the films did not curl up at the edges).
[0113] Based on the above results, the compositions of the present invention provide an excellent barrier over damaged skin to prevent scratching and further damage. The films also discourage the consumer from scratching the affected area of skin and function to deliver active ingredients to the skin.
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A composition comprising: a film forming polymer; a low boiling point solvent; a high boiling point solvent; and at least one active ingredient is disclosed. The composition is useful for protecting damaged skin and delivering active ingredients to the skin.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a multi-layered non-woven fabric which provides high air permeance, high water-pressure resistance, relatively small pores, and low pressure difference characteristics, and to a process and an apparatus for producing the multi-layered nonwoven fabric.
[0003] 2. Description of the Related Art
[0004] Referring to FIG. 1, a conventional process for producing a spun-bonded non-woven fabric generally includes forcing a polymeric composition through a spinning nozzle 11 to form long filaments, depositing the long filaments onto a depositing device 12 to form a web, and passing the web between a pair of heat embossing rollers 13 to form a non-woven fabric. However, the non-woven fabric produced from the conventional process includes only one layer and only one filament component with a single melting point. In addition, when the single-melting point filaments are heat-treated by the heat embossing rollers 13 , they cannot provide a non-woven fabric with satisfactory surface softness and comfortable feel.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a multi-layered non-woven fabric with high air permeance, high water-pressure resistance, relatively small pores, and low pressure difference characteristics.
[0006] Another object of the present invention is to provide a process for producing the multi-layered non-woven fabric.
[0007] Yet another object of the present invention is to provide an apparatus for producing the multi-layered non-woven fabric.
[0008] According to one aspect of the present invention, a process for producing a multi-layered non-woven fabric includes: (a) forming a plurality of non-woven fabric layers from a plurality of filament materials which are produced respectively from a plurality of spinning devices disposed along an advancing forming screen; (b) forming at least one of the filament materials as a composite filament material which includes at least two filament components having high and low melting points by means of one of the spinning devices; and (c) depositing the filament materials on the advancing forming screen one over the other to form a plurality of non-woven fabric layers.
[0009] According to another aspect of the present invention, a multi-layered non-woven fabric includes a plurality of non-woven fabric layers bonded together to form a laminate. The non-woven fabric layers are obtained from a plurality of filament materials which are produced respectively by a plurality of spinning devices disposed along an advancing forming screen. At least one of the non-woven fabric layers contains a composite filament material which includes at least two filament components of high and low melting points.
[0010] According to yet another aspect of the present invention, an apparatus for producing a multi-layered non-woven fabric includes an advancing forming screen, and a plurality of spinning devices disposed successively adjacent to and along the direction of the forming screen so as to extrude a plurality of filament materials, respectively, and depositing means for depositing the filament materials one over the other on the forming screen to form a plurality of non-woven fabric layers. At least one of the spinning devices produces a composite filament material from at least two polymeric compositions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, in which:
[0012] [0012]FIG. 1 is a schematic view illustrating a conventional process and apparatus for producing a nonwoven fabric;
[0013] [0013]FIG. 2 is a schematic view illustrating a process and apparatus embodying the present invention;
[0014] [0014]FIG. 3 is a schematic view illustrating another process and apparatus embodying the present invention; and
[0015] [0015]FIG. 4 illustrates cross-sections of bicomponent filaments that can be formed by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Referring to FIG. 2, the preferred embodiment of an apparatus according to the present invention is shown to include an advancing forming screen 22 which is configured as a moving belt of a belt conveyor 21 , a first spun-bonding spinning device 30 , a first melt-blowing spinning device 40 , a second melt-blowing spinning device 50 , a second spun-bonding spinning device 60 , and a depositing unit which includes a suction device 23 disposed below the forming screen 22 . The spinning devices 30 , 40 , 50 , 60 are disposed successively adjacent to and along the advancing direction of the forming screen 22 so as to extrude a plurality of filament materials of different types on the forming screen 22 . In practice, the spinning devices 30 , 40 , 50 , 60 can be selectively activated to form a non-woven fabric with a desired number and desired types of fabric layers.
[0017] The first spun-bonding spinning device 30 includes two separate feed tanks 31 , 31 ′ for respectively receiving two different polymeric compositions having high and low melting points, two extruders 32 , 32 ′ connected respectively to the feed tanks 31 , 31 ′ for extruding the polymeric compositions, respectively, two filters 33 , 33 ′ for filtering the extruded polymeric compositions, respectively, a spinning box 35 connected to the filters 33 , 33 ′, and a pump 34 for pumping the filtered polymeric compositions into the spinning box 35 . The spinning box 35 has a spinning nozzle for forming the polymeric compositions into a bicomponent composite filament material that includes two different filament components having high and low melting points. A cooling chamber 351 is provided below the spinning nozzle of the spinning box 35 for cooling and setting the composite filament material. A high-speed air flow 36 at the ambient temperature is directed to a bottom outlet 352 of the cooling chamber 351 for suctioning and drawing the spun-bonded composite filament material out of the cooling chamber 351 via the bottom outlet 352 . The suction device 23 disposed below the forming screen 22 produces a downward suction force to deposit the spun-bonded composite filament material on the forming screen 22 to form a first spun-bonded composite fabric layer.
[0018] The spun-bonded fabric layer includes long continuous filaments, and is prepared from a bicomponent combination selected from the group consisting of a combination of polypropylene and polyethylene, a combination of polyethylene terephthalate and polyethylene, a combination of polyethylene terephthalate and polypropylene, a combination of polypropylene and compound polypropylene (COPP) with a low melting point, a combination of polyethylene terephthalate and compound polyethylene terephthalate, a combination of nylon with a high melting point and nylon with a low melting point, and the like. The bicomponent composite filament material produced from the spinning nozzle of the first spun-bonding spinning device 30 includes a bicomponent filament with one of the structures shown in FIG. 4, such as a core-sheath structure or a side-by-side structure, depending on the design of the spinning nozzle.
[0019] The first melt-blowing spinning device 40 is disposed downstream of the first spun-bonding spinning device 30 , and includes two separate feed tanks 41 , 41 ′ for respectively receiving two different polymeric compositions of different melting points, two extruders 42 , 42 ′ connected respectively to the feed tanks 41 , 41 ′ for extruding the polymeric compositions, respectively, two filters 43 , 43 ′ for filtering the extruded polymeric compositions, respectively, a spinning box 45 connected to the filters 43 , 43 ′, and a pump 44 for pumping the filtered polymeric compositions into the spinning box 45 . The spinning box 45 has a spinning nozzle for forming the polymeric compositions into a bicomponent composite filament material that includes two different filament components. A cooling chamber 451 is provided below the spinning nozzle of the spinning box 45 for cooling and setting the composite filament material. A high-speed air flow 46 at the ambient temperature is guided to a bottom outlet 452 of the cooling chamber 451 for drawing the meltblown composite filament material out of the cooling chamber 451 via the outlet 452 . With the suction device 23 disposed below the forming screen 22 , the melt-blown composite filament material is deposited on top of the first spun-bonded composite fabric layer to form a first melt-blown composite fabric layer on the first spun-bonded composite fabric layer.
[0020] The second melt-blown spinning device 50 has a structure similar to that of the first melt-blown spinning device 40 , and operates in a manner similar to that of the first melt-blown spinning device 40 . The second melt-blown spinning device 50 is disposed downstream of the first melt-blown spinning device 40 so as to produce a second melt-blown composite fabric layer on the first melt-blown composite fabric layer.
[0021] Each of the first and second melt-blown fabric layers includes fine filaments, and is prepared from a bicomponent combination selected from the group consisting of a combination of polypropylene and polyethylene, a combination of polyethylene terephthalate and polyethylene, a combination of polyethylene terephthalate and polypropylene, a combination of polypropylene and compound polypropylene (COPP) with a low melting point, a combination of polyethylene terephthalate and compound polyethylene terephthalate with a low melting point, a combination of nylon with a high melting point and nylon with a low melting point, and the like. The melt-blown composite filament material includes a bicomponent filament with one of the structures shown in FIG. 4, such as a core-sheath structure or a side-by-side structure, depending on the design of the spinning nozzle. The melt-blown composite filament material has an average diameter smaller than that of the spun-bonded composite filament material. The average diameter of the meltblown composite filament material is less than 5 μm. The melt-blown composite fabric layer has an orientation of filaments with a more uniform compactness to obtain low pressure difference characteristics.
[0022] The second spun-bonded spinning device 60 has a structure similar to that of the first spun-bonded spinning device 30 , and is operable in a manner similar to that of the first spun-bonded spinning device 30 . The second spun-bonded spinning device 60 is disposed downstream of the second melt-blown spinning device 50 so as to produce a second spun-bonded composite fabric layer on the second melt-blown composite fabric layer.
[0023] The multi-layer non-woven fabric produced from the above-described process includes a first spun-bonded composite fabric layer, a first melt-blown composite fabric layer formed on the first spun-bonded composite fabric layer, a second melt-blown composite fabric layer formed on the first melt-blown composite fabric layer, and a second spun-bonded composite fabric layer formed on the second melt-blown composite fabric layer. The composite fabric layers are bonded together to form a laminate. To obtain a good structural connection between the adjacent composite fabric layers, one of the following heat treatments may be conducted.
[0024] (1) The laminate is passed between a pair of heat-embossing rollers 71 to heat-bond the filaments of the composite fabric layers.
[0025] (2) The laminate is passed through a hot air box 72 at a temperature not higher than the high melting point of the filament component of the spun-bonded and meltblown composite fabric layers so as to solely heat-bond the filament component of the lower melting point.
[0026] After heat treatment, the laminate is taken up via a rolling-up device 90 . Because, after the heat treatment with the hot air box 72 , the filaments having high melting point in the fabric layers are not subjected to heat-bonding, the non-woven fabric thus produced has a loose and soft structure.
[0027] Referring to FIG. 3, there is shown another apparatus according to the present invention which includes an advancing forming screen 22 , a first spun-bonding spinning device 30 , a first melt-blowing spinning device 40 , a second melt-blowing spinning device 50 , a second spun-bonding spinning device 60 , and a depositing unit which includes a suction device 23 disposed below the forming screen 22 . The spinning devices 30 , 40 , 50 , 60 are disposed successively adjacent to and along the advancing direction of the forming screen 22 so as to extrude a plurality of filament material of different types on the forming screen 22 . As with the previous embodiment, the spinning devices 30 , 40 , 50 , 60 can be selectively activated to form a non-woven fabric with a desired number and desired types of fabric layers. The filament materials produced from the spinning devices 30 , 40 , 50 , 60 have one or more composite filament structures whose cross-sections are shown in FIG. 4. These filaments can be split. A water jet device 80 is disposed at the end of the forming screen 22 to produce a jet of water onto the laminate of the non-woven fabric layers for splitting the composite filaments in the composite fabric layers into finer filaments. In this manner, the filament materials in the fabric layers can be interlaced more uniformly. Thus, the nonwoven fabric has high air permeance and high water-pressure resistance.
[0028] The multi-layered non-woven fabric produced from the process of the present invention is suitable for use as a filter for filtering water and air. Moreover, since the non-woven fabric according to the present invention is relatively soft, the non-woven fabric can thus be used in making diapers, sanitary napkins, surgical garments, surgical caps, surgical mouthpieces, etc.
[0029] With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.
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A process for producing a multi-layered non-woven fabric includes: (a) forming a plurality of non-woven fabric layers from a plurality of filament materials which are produced respectively from a plurality of spinning devices disposed along an advancing forming screen; (b) forming at least one of the filament materials as a composite filament material which includes at least two filament components having high and low melting points by means of one of the spinning devices; and (c) depositing the filament materials on the advancing forming screen one over the other to form a plurality of non-woven fabric layers. An apparatus to carry out the process, and a multi-layered non-woven fabric produced thereby are also disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 09/945,280 filed on Aug. 31, 2001, presently pending.
FIELD OF THE INVENTION
The present invention relates generally to high-pressure ducting and more particularly to high-pressure liquid ducting for propellants in rocket engines.
BACKGROUND OF THE INVENTION
High-pressure liquid propellant ducts on rocket engines are generally heavy and can represent approximately 10-20 percent of the total weight of the engine. Generally, the ducts comprise a tubular section that is joined to a flange portion at each end thereof to form a section of high-pressure liquid ducting. The section of high-pressure liquid ducting is further joined to another section of ducting or to another component of the rocket engine such as a propellant feed tank or an inlet to the rocket engine of, for example, an aerospace vehicle.
In the known art, high-pressure liquid propellant ducts are fabricated from nickel or iron-based superalloys such as 625 or 718, which have relatively high densities and thus contribute significantly to the weight of a rocket engine. To minimize weight, therefore, the ducts are ideally fabricated from materials with high specific strength and toughness for the tubular sections, which generally perform as pressure vessels. Similarly, the flange portions are fabricated from materials with high specific stiffness and hardness, wherein the flange portion performs primarily as a sealing section.
At the ambient or cryogenic temperatures of typical liquid propellant ducts, superalloys do not have an ideal high specific strength for the tubular section or an ideal high specific stiffness for the flange portion. For example, when a superalloy tubular section has been designed with sufficient strength to accommodate propellant pressure, the associated stiffness is relatively high such that small misalignments of the flange portions results in high stresses therein after assembly of the duct. Further, the assembly stress can represent approximately 60 percent of the total flange loading. Moreover, welding, weld inspection, and any rework necessary during assembly of high-pressure liquid ducts of the known art adds substantial cost to the rocket engine.
High strength aluminum alloys, although approximately one third the density of superalloys, have not been used for propellant ducts for a variety of reasons. Generally, the high strength condition in conventional aluminum alloys is achieved by a solution heat treat, followed by a water quench and age, which introduces constraints on forming, welding, and maximum component section thickness. Unfortunately, the aluminum alloy comprises undesirable residual stresses, anisotropic properties, and susceptibility to stress corrosion as a result of the heat treat, water quenching, and aging processes.
Further, conventional aluminum alloys generally have low stiffness, and thus any potential weight benefits of high specific strength in the stiffness-critical flange portions have not been achievable. Moreover, the high coefficient of thermal expansion of conventional aluminum alloys would require an excessively high preload in steel or superalloy bolts that are used to fasten and seal the flange portions to prevent loosening of the bolts during a chill-down process.
Accordingly, there remains a need in the art for lightweight high-pressure liquid ducts comprising aluminum alloys to provide significant weight savings over superalloy ducting of the known art. The high-pressure liquid ducts should comprise lightweight tubular sections in addition to lightweight flange portions, which are fabricated and assembled using manufacturing techniques applicable to the particular materials employed throughout the ducting.
SUMMARY OF THE INVENTION
In one preferred form, the present invention provides a nanophase composite duct assembly that comprises a high pressure liquid duct formed from an ultra-high strength nanophase aluminum alloy, which is joined with a high-pressure liquid ducting flange formed from a ceramic particulate in a metal matrix such as aluminum. Preferably, the duct is joined with the flange using solid-state friction welding such as inertia welding or friction stir welding, among others, as described in greater detail below.
The nanophase aluminum alloy duct is preferably formed by synthesizing a nanophase aluminum alloy to form a billet, extruding the billet into a predetermined geometrical shape, followed by bending the extruded billet into a profile to form the high-pressure liquid duct. Further, the extruded billet may be flow formed prior to bending in order to achieve a precise wall thickness with relatively tight tolerances for a particular application.
Generally, the nanophase aluminum alloy is synthesized by a powder processing sequence of cryogenic milling, out-gassing, and hot isostatic pressing (HIP) to form the billet. The billet is then extruded into a predetermined geometrical shape such as a cylindrical tube for use in many ducting applications for rocket engines. Further, in order to meet the dimensional requirements of rocket engine and other applications, the extruded billet is further flow formed to reduce the wall thickness of the duct to a desired dimension prior to bending, wherein relatively tight tolerances are maintained along the entire length of the extruded billet. (Generally, flow forming is a manufacturing technique that is used for high precision, high tolerance net shape component fabrication).
In preparation of the extrusion process, a center hole is machined through the center of the billet and an internal liner is secured within the center hole, along with an extrusion mandrel. A leader is then positioned at one end of the billet and a follower is positioned at another end of the billet, and an extrusion jacket is placed over the billet, the leader, and the follower. The billet is then extruded through an extrusion die, along with the internal liner, the extrusion jacket, the leader, and the follower, to form an extruded billet having a predetermined geometrical shape. Furthermore, other extrusion methods commonly known in the art may be employed in accordance with the teachings of the present invention. Accordingly, the preferred extrusion method as described herein shall not be construed as limiting the scope of the present invention.
The high-pressure liquid ducting flange comprising a ceramic particulate in a metal matrix is preferably formed by powder processing or by a liquid metal infiltration process. Further, the metal matrix is preferably aluminum in one form of the present invention. The high-pressure liquid ducting flange in one form comprises a series of radial holes wherein bolts are used to secure the flange to another flange portion or to another component within the systems of, for example, a rocket engine. In another embodiment, the high-pressure liquid ducting flange is a two-piece component comprising a nanophase flange joined to a discontinuously reinforced aluminum (DRA) base, preferably using inertia welding, wherein the nanophase flange is then joined to the high-pressure liquid duct.
The high-pressure liquid duct is joined to the high-pressure liquid ducting flange preferably using solid-state friction welding. The solid-state friction welding may comprise inertia welding or friction stir welding, or a combination of both inertia welding and friction stir welding, among others. Furthermore, the nanophase composite duct assembly may also comprise a collar between the high-pressure liquid duct and the high-pressure liquid ducting flange to further seal and secure the interface therebetween. Similarly, the collar is preferably welded to the high-pressure liquid duct and the high-pressure liquid ducting flange using solid-state friction welding.
Although the present invention is directed to a high-pressure liquid duct within a rocket engine, the invention may also be applicable to other high-pressure ducting applications. Accordingly, the reference to rocket engines throughout the description of the invention herein should not be construed as limiting the scope of the present invention.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is an orthogonal view of a nanophase composite duct assembly in accordance with the present invention;
FIG. 2 is an exploded view of a nanophase aluminum alloy billet, an internal sleeve, an extrusion mandrel, a leader, a follower, and an extrusion jacket in accordance with the present invention;
FIG. 3 is a side view of a nanophase aluminum alloy billet, an internal sleeve, an extrusion mandrel, a leader, a follower, and an extrusion jacket in accordance with the present invention;
FIG. 4 is a side view of an extruded billet in accordance with the present invention;
FIG. 5 is an orthogonal view of a high-pressured liquid ducting flange in accordance with the present invention;
FIG. 6 is a side view of a high-pressure liquid duct joined with a high-pressure liquid ducting flange in accordance with the present invention; and
FIG. 7 is a side view of a collar around a high-pressure liquid duct and a high-pressure liquid ducting flange in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring to the drawings, a nanophase composite duct assembly according to the present invention is illustrated and generally indicated by reference numeral 10 in FIG. 1 . As shown, the nanophase composite duct assembly 10 generally comprises a high-pressure liquid duct 12 joined to a high-pressure liquid ducting flange 14 . Preferably, the high-pressure liquid duct 12 is an ultra-high strength nanophase aluminum alloy and the high-pressure liquid ducting flange 14 is formed from a ceramic particulate in a metal matrix, wherein the metal matrix is preferably aluminum. Accordingly, the nanophase composite duct assembly 10 provides significant weight and cost savings over superalloy high-pressure ducting of the known art.
The high-pressure liquid duct 12 is preferably formed by first synthesizing the nanophase aluminum alloy using powder processing. More specifically, the nanophase aluminum alloy is milled in a cryogenic high-energy ball mill while submerged in liquid nitrogen. After cryogenic milling, the nanophase aluminum alloy is out-gassed and pressed into a billet using hot isostatic pressing (HIP). As a result, a nanophase aluminum alloy billet is produced that is then preferably extruded into predetermined geometrical shape as described in greater detail below. Alternately, the nanophase aluminum alloy billet may be formed into the desired geometrical shape using other methods commonly known in the art such as machining, pultrusion, and die forming, among others. Accordingly, the extrusion process as described herein shall not be construed as limiting the scope of the present invention.
Referring to FIGS. 2 and 3 , a nanophase aluminum alloy billet 16 is illustrated along with an internal sleeve 18 , an extrusion mandrel 20 , a leader 22 , a follower 24 , and an extrusion jacket 26 , which are used to contain and extrude the nanophase aluminum alloy billet 16 during the extrusion process. As further shown, a center hole 28 is created through the nanophase aluminum alloy billet 16 , preferably by machining, and the internal sleeve 18 along with the extrusion mandrel 20 are placed within the center hole 28 . Further, the leader 22 is placed at one end of the nanophase aluminum alloy billet 16 , and the follower 24 is placed at another end thereof as shown. Generally, the leader 22 and the follower 24 are employed to increase the yield of the extrusion process and to provide consistent material properties.
The mandrel 20 further comprises a collar 21 as shown, which is preferably larger in diameter than the extrusion jacket 26 . Further, the mandrel 20 and the internal sleeve 18 extend through the extrusion jacket 26 as illustrated. Accordingly, the internal sleeve 18 is preferably split to form ears 29 , which prevent the internal sleeve 18 from slipping during the extrusion process.
As further shown, the extrusion jacket 26 is placed over the nanophase aluminum alloy billet 16 , the leader 22 , and the follower 24 . Generally, the extrusion jacket 26 is provided to encapsulate the nanophase aluminum alloy billet 16 during the extrusion process. Preferably, the extrusion jacket 26 , along with the internal sleeve 18 , are a copper material, and the leader 22 and the follower 24 are preferably an aluminum material such as 6061-T6.
The extrusion jacket 26 , the nanophase aluminum alloy billet 16 with the internal sleeve 18 and the extrusion mandrel 20 , the leader 22 , and the follower 24 are then placed in an extrusion die (not shown), wherein the mandrel 20 is activated to force the aluminum alloy billet 16 with the internal sleeve 18 , along with the extrusion jacket 26 , the leader 22 , and the follower 24 through the die to form an extruded billet having a predetermined geometrical shape. Preferably, the nanophase aluminum alloy billet 16 , the leader 22 , and the extrusion jacket 26 are preheated prior to extrusion, while the follower 24 remains at approximately room temperature. Further, the internal sleeve 18 is also preheated, however, at temperatures somewhat higher than the nanophase aluminum alloy billet 16 , the leader 22 , and the extrusion jacket 26 .
In one form of the present invention, a nanophase aluminum alloy billet having a diameter of approximately 9.125 inches is extruded at an area reduction ratio of approximately 20:1. The nanophase aluminum alloy billet 16 , the leader 22 , and the extrusion jacket 26 are preheated to approximately 400° F., the follower 24 remains at approximately room temperature, the internal sleeve 18 is preheated to approximately between 550° F. and 610° F., and the die temperature is approximately between 350° F. and 500° F. with an extruder having approximately a 5,000 ton capacity. Accordingly, a high-pressure liquid duct is extruded in one form of the present invention that has an outer diameter of approximately 3.35 inches and an inner diameter of approximately 2.80 inches. Additionally, alternate dimensions according to specific applications may also be achieved in accordance with the teachings of the present invention.
Referring to FIG. 4 , an extruded billet 30 is illustrated, which is a result of the extrusion process as described herein. The geometrical shape in one form is tubular as shown, however, other geometrical shapes may also be created according to specific application requirements, including constant and non-constant cross sections. As shown, the extruded billet 30 comprises an outer diameter 32 , an inner diameter 34 , and a wall thickness 36 , wherein the outer diameter 32 is significantly smaller than the diameter of the nanophase aluminum alloy billet 16 (not shown) prior to the extrusion process.
Once the nanophase aluminum alloy billet 16 is extruded into the predetermined geometrical shape to form the extruded billet 30 , the extruded billet 30 is preferably flow formed to further reduce the wall thickness 36 to a desired dimension. Generally, flow forming produces precise and consistent dimensions along the entire length of the extruded billet 30 within relatively tight tolerances. Accordingly, for applications requiring tighter dimensional control, flow forming is employed after the extrusion process as described herein.
To complete the high-pressure liquid duct 12 , the extruded billet undergoes a bending operation to form a profile that corresponds with the final shape of the nanophase composite duct assembly 10 . In one form, the geometry of the high-pressure liquid duct 12 is tubular as shown, and thus tube bending operations as commonly known in the art are employed to create the desired profile. Accordingly, further forming methods known in the art may also be employed in accordance with the teachings of the present invention.
The high-pressure liquid duct 12 may also be formed using other methods commonly known in the art such as die forming, pultrusion, or blow forming, among others. Accordingly, the description of extrusion and bending processes herein to form the high-pressure liquid duct 12 shall not be construed as limiting the scope of the present invention.
Referring to FIG. 5 , the high-pressure liquid ducting flange 14 is illustrated, wherein a plurality of radial holes 40 are formed therethrough for bolts (not shown) that secure the high-pressure liquid ducting flange 14 to other portions of rocket engine systems. The high-pressure liquid ducting flange 14 generally comprises ceramic particulates in a metal matrix and is preferably formed by powder processing or liquid metal infiltration. In one form, the ceramic particulate comprises B 4 C (boron carbide) in an A356 (aluminum) matrix, wherein the percent by volume of B 4 C is approximately 52 percent. Additional materials for the ceramic particulates and the metal matrix, further in various percentages, may also be employed in accordance with the teachings of the present invention. For example, in one form of the present invention, a SiC (silicon carbide) particulate is employed at a volume by percent of approximately 18 percent within an aluminum matrix.
In another form of the present invention, the high-pressure liquid ducting flange 14 is a two-piece component comprising a nanophase flange joined to a discontinuously reinforced metal matrix base (not shown). Preferably, the nanophase flange is joined to the discontinuously reinforced metal matrix base using inertia welding to form the completed high-pressure liquid ducting flange 14 . Further, the nanophase flange portion of the high-pressure liquid ducting flange 14 is joined to the high-pressure liquid duct, while the discontinuously reinforced metal matrix base portion is joined to other portions of rocket engine systems as previously described. Accordingly, the nanophase flange portion defines a tapered outer surface that generally transitions from the diameter of the high-pressure liquid duct 12 to the larger diameter of the discontinuously reinforced metal matrix base portion. Preferably, the metal matrix is aluminum for the discontinuously reinforced metal matrix base portion.
Referring now to FIG. 6 , the high-pressure liquid duct 12 is joined to the high-pressure liquid ducting flange 14 along an interface 41 as shown. Preferably, the high-pressure liquid duct 12 and the high-pressure liquid ducting flange 14 are joined using solid-state friction welding along the interface 41 . The solid-state friction welding may comprise inertia welding, friction stir welding, or a combination of both inertia welding and friction stir welding, among others commonly known in the art.
As shown in FIG. 7 , a collar 42 may also be employed around the joint between the high-pressure liquid duct 12 and the high-pressure liquid ducting flange 14 to further secure and seal the interface therebetween. Similarly, the collar 42 is preferably secured to the high-pressure liquid duct 12 and the high-pressure liquid ducting flange 14 along interfaces 43 using solid-state friction welding as described herein.
Accordingly, a lightweight, low cost composite duct assembly is provided in accordance with the teachings of the present invention. The composite duct assembly comprises a lightweight nanophase aluminum alloy duct that is joined with a lightweight ceramic particulate reinforced aluminum matrix flange, which together with the joining methods as described herein provide significant weight savings over superalloy ducting of the known art.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the substance of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A nanophase composite duct assembly and method of fabricating the same are provided that comprise an ultra-high strength nanophase aluminum alloy duct joined with a ceramic particulate reinforced metal matrix fitting, preferably using solid-state friction welding. The nanophase aluminum alloy duct is fabricated by extruding a billet formed by a process of cryogenic milling the alloy, followed by out-gassing, then hot isostatic pressing. The fitting is fabricated by combining a ceramic particulate with a metal matrix, preferably by powder processing or liquid metal infiltration. Further, the solid-state friction welding may comprise inertial welding, friction stir welding, or a combination thereof. As a result, a lightweight duct assembly is provided for high-pressure liquids such as propellants in rocket engines.
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FIELD OF THE INVENTION
[0001] This invention relates to the field of characterizing the existence of a disease state; particularly to the utilization of mass spectroscopy to elucidate particular biopolymer markers indicative of disease state, and most particularly to specific biopolymer sequences having a unique relationship to at least one particular disease state.
BACKGROUND OF THE INVENTION
[0002] Methods utilizing mass spectrometry for the analysis of a target polypeptide have been taught wherein the polypeptide is first solubilized in an appropriate solution or reagent system. The type of solution or reagent system, e.g., comprising an organic or inorganic solvent, will depend on the properties of the polypeptide and the type of mass spectrometry performed and are well known in the art (see, e.g., Vorm et al. (1994) Anal. Chem. 66:3281 (for MALDI) and Valaskovic et al. (1995) Anal. Chem. 67:3802 (for ESI). Mass spectrometry of peptides is further disclosed, e.g., in WO 93/24834 by Chait et al.
[0003] In one prior art embodiment, the solvent is chosen so that the risk that the molecules may be decomposed by the energy introduced for the vaporization process is considerably reduced, or even fully excluded. This can be achieved by embedding the sample in a matrix, which can be an organic compound, e.g., sugar, in particular pentose or hexose, but also polysaccharides such as cellulose. These compounds are decomposed thermolytically into CO 2 and H 2 O so that no residues are formed which might lead to chemical reactions. The matrix can also be an inorganic compound, e.g., nitrate of ammonium which is decomposed practically without leaving any residues. Use of these and other solvents are further disclosed in U.S. Pat. No. 5,062,935 by Schlag et al.
[0004] Prior art mass spectrometer formats for use in analyzing the translation products include ionization (I) techniques, including but not limited to matrix assisted laser desorption (MALDI), continuous or pulsed electrospray (ESI) and related methods (e.g., IONSPRAY or THERMOSPRAY), or massive cluster impact (MCI); these ion sources can be matched with detection formats including linear or non-linear reflection time-of-flight (TOF), single or multiple quadropole, single or multiple magnetic sector, Fourier Transform ion cyclotron resonance (FTICR), ion trap, and combinations thereof (e.g., ion-trap/time-of-flight). For ionization, numerous matrix/wavelength combinations (MALDI) or solvent combinations (ESI) can be employed. Subattomole levels of protein have been detected, for example, using ESI (Valaskovic, G. A. et al., (1996) Science 273:1199-1202) or MALDI (Li, L. et al., (1996) J. Am. Chem. Soc. 118:1662-1663) mass spectrometry.
[0005] ES mass spectrometry has been introduced by Fenn et al. (J. Phys. Chem. 88, 4451-59 (1984); PCT Application No. WO 90/14148) and current applications are summarized in recent review articles (R. D. Smith et al., Anal. Chem. 62, 882-89 (1990) and B. Ardrey, Electrospray Mass Spectrometry, Spectroscopy Europe, 4, 10-18 (1992)). MALDI-TOF mass spectrometry has been introduced by Hillenkamp et al. (“Matrix Assisted UV-Laser Desorption/Ionization: A New Approach to Mass Spectrometry of Large Biomolecules,” Biological Mass Spectrometry (Burlingame and McCloskey, editors), Elsevier Science Publishers, Amsterdam, pp. 49-60, 1990). With ESI, the determination of molecular weights in femtomole amounts of sample is very accurate due to the presence of multiple ion peaks which all could be used for the mass calculation.
[0006] The mass of the target polypeptide determined by mass spectrometry is then compared to the mass of a reference polypeptide of known identity. In one embodiment, the target polypeptide is a polypeptide containing a number of repeated amino acids directly correlated to the number of trinucleotide repeats transcribed/translated from DNA; from its mass alone the number of repeated trinucleotide repeats in the original DNA which coded it, may be deduced.
[0007] U.S. Pat. No. 6,020,208 utilizes a general category of probe elements (i.e., sample presenting means) with Surfaces Enhanced for Laser Desorption/Ionization (SELDI), within which there are three (3) separate subcategories. The SELDI process is directed toward a sample presenting means (i.e., probe element surface) with surface-associated (or surface-bound) molecules to promote the attachment (tethering or anchoring) and subsequent detachment of tethered analyte molecules in a light-dependent manner, wherein the said surface molecule(s) are selected from the group consisting of photoactive (photolabile) molecules that participate in the binding (docking, tethering, or crosslinking) of the analyte molecules to the sample presenting means (by covalent attachment mechanisms or otherwise).
[0008] PCT/EP/04396 teaches a process for determining the status of an organism by peptide measurement. The reference teaches the measurement of peptides in a sample of the organism which contains both high and low molecular weight peptides and acts as an indicator of the organism's status. The reference concentrates on the measurement of low molecular weight peptides, i.e. below 30,000 Daltons, whose distribution serves as a representative cross-section of defined controls. Contrary to the methodology of the instant invention, the '396 patent strives to determine the status of a healthy organism, i.e. a “normal” and then use this as a reference to differentiate disease states. The present inventors do not attempt to develop a reference “normal”, but rather strive to specify particular markers which are evidentiary of at least one specific disease state, whereby the presence of said marker serves as a positive indicator of disease. This leads to a simple method of analysis which can easily be performed by an untrained individual, since there is a positive correlation of data. On the contrary, the '396 patent requires a complicated analysis by a highly trained individual to determine disease state versus the perception of non-disease or normal physiology.
[0009] Richter et al, Journal of Chromatography B, 726(1999) 25-35, refer to a database established from human hemofiltrate comprised of a mass database and a sequence database. The goal of Richter et al was to analyze the composition of the peptide fraction in human blood. Using MALDI-TOF, over 20,000 molecular masses were detected representing an estimated 5,000 different peptides. The conclusion of the study was that the hemofiltrate (HF) represented the peptide composition of plasma. No correlation of peptides with relation to normal and/or disease states is made.
[0010] As used herein, “analyte” refers to any atom and/or molecule; including their complexes and fragment ions. In the case of biological molecules/macromolecules or “biopolymers”, such analytes include but are not limited to: proteins, peptides, DNA, RNA, carbohydrates, steroids, and lipids. Note that most important biomolecules under investigation for their involvement in the structure or regulation of life processes are quite large (typically several thousand times larger than H 2 O.
[0011] As used herein, the term “molecular ions” refers to molecules in the charged or ionized state, typically by the addition or loss of one or more protons (H + )
[0012] As used herein, the term “molecular fragmentation” or “fragment ions” refers to breakdown products of analyte molecules caused, for example, during laser-induced desorption (especially in the absence of added matrix).
[0013] As used herein, the term “solid phase” refers to the condition of being in the solid state, for example, on the probe element surface.
[0014] As used herein, “gas” or “vapor phase” refers to molecules in the gaseous state (i.e., in vacuo for mass spectrometry).
[0015] As used herein, the term “analyte desorption/ionization” refers to the transition of analytes from the solid phase to the gas phase as ions. Note that the successful desorption/ionization of large, intact molecular ions by laser desorption is relatively recent (circa 1988)—the big breakthrough was the chance discovery of an appropriate matrix (nicotinic acid).
[0016] As used herein, the term “gas phase molecular ions” refers to those ions that enter into the gas phase. Note that large molecular mass ions such as proteins (typical mass=60,000 to 70,000 times the mass of a single proton) are typically not volatile (i.e., they do not normally enter into the gas or vapor phase). However, in the procedure of the present invention, large molecular mass ions such as proteins do enter the gas or vapor phase.
[0017] As used herein in the case of MALDI, the term “matrix” refers to any one of several small, acidic, light absorbing chemicals (e.g., nicotinic or sinapinic acid) that is mixed in solution with the analyte in such a manner so that, upon drying on the probe element, the crystalline matrix-embedded analyte molecules are successfully desorbed (by laser irradiation) and ionized from the solid phase (crystals) into the gaseous or vapor phase and accelerated as intact molecular ions. For the MALDI process to be successful, analyte is mixed with a freshly prepared solution of the chemical matrix (e.g., 10,000:1 matrix:analyte) and placed on the inert probe element surface to air dry just before the mass spectrometric analysis. The large fold molar excess of matrix, present at concentrations near saturation, facilitates crystal formation and entrapment of analyte.
[0018] As used herein, “energy absorbing molecules (EAM)” refers to any one of several small, light absorbing chemicals that, when presented on the surface of a probe, facilitate the neat desorption of molecules from the solid phase (i.e., surface) into the gaseous or vapor phase for subsequent acceleration as intact molecular ions. The term EAM is preferred, especially in reference to SELDI. Note that analyte desorption by the SELDI process is defined as a surface-dependent process (i.e., neat analyte is placed on a surface composed of bound EAM). In contrast, MALDI is presently thought to facilitate analyte desorption by a volcanic eruption-type process that “throws” the entire surface into the gas phase. Furthermore, note that some EAM when used as free chemicals to embed analyte molecules as described for the MALDI process will not work (i.e., they do promote molecular desorption, thus they are not suitable matrix molecules).
[0019] As used herein, “probe element” or “sample presenting device” refers to an element having the following properties: it is inert (for example, typically stainless steel) and active (probe elements with surfaces enhanced to contain EAM and/or molecular capture devices).
[0020] As used herein, “MALDI” refers to Matrix-Assisted Laser Desorption/Ionization.
[0021] As used herein, “TOF” stands for Time-of-Flight.
[0022] As used herein, “MS” refers to Mass Spectrometry.
[0023] As used herein “MALDI-TOF MS” refers to Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
[0024] As used herein, “ESI” is an abbreviation for Electrospray ionization.
[0025] As used herein, “chemical bonds” is used simply as an attempt to distinguish a rational, deliberate, and knowledgeable manipulation of known classes of chemical interactions from the poorly defined kind of general adherence observed when one chemical substance (e.g., matrix) is placed on another substance (e.g., an inert probe element surface). Types of defined chemical bonds include electrostatic or ionic (+/−) bonds (e.g., between a positively and negatively charged groups on a protein surface), covalent bonds (very strong or “permanent” bonds resulting from true electron sharing), coordinate covalent bonds (e.g., between electron donor groups in proteins and transition metal ions such as copper or iron), and hydrophobic interactions (such as between two noncharged groups).
[0026] As used herein, “electron donor groups” refers to the case of biochemistry, where atoms in biomolecules (e.g, N, S, O) “donate” or share electrons with electron poor groups (e.g., Cu ions and other transition metal ions).
[0027] With the advent of mass spectroscopic methods such as MALDI and SELDI, researchers have begun to utilize a tool that holds the promise of uncovering countless biopolymers which result from translation, transcription and post-translational transcription of proteins from the entire genome.
[0028] Operating upon the principles of retentate chromatography, SELDI MS involves the adsorption of proteins, based upon their physico-chemical properties at a given pH and salt concentration, followed by selectively desorbing proteins from the surface by varying pH, salt, or organic solvent concentration. After selective desorption, the proteins retained on the SELDI surface, the “chip”, can be analyzed using the CIPHERGEN protein detection system, or an equivalent thereof. Retentate chromatography is limited, however, by the fact that if unfractionated body fluids, e.g. blood, blood products, urine, saliva, and the like, along with tissue samples, are applied to the adsorbent surfaces, the biopolymers present in the greatest abundance will compete for all the available binding sites and thereby prevent or preclude less abundant biopolymers from interacting with them, thereby reducing or eliminating the diversity of biopolymers which are readily ascertainable.
[0029] If a process could be devised for maximizing the diversity of biopolymers discernable from a sample, the ability of researchers to accurately determine the relevance of such biopolymers with relation to one or more disease states would be immeasurably enhanced.
SUMMARY OF THE INVENTION
[0030] The instant invention is characterized by the use of a combination of preparatory steps in conjunction with SELDI mass spectroscopy and time-of-flight detection procedures to maximize the diversity of biopolymers which are verifiable within a particular sample. The cohort of biopolymers verified within a sample is then viewed with reference to their ability to evidence at least one particular disease state; thereby enabling a diagnostician to gain the ability to characterize either the presence or absence of said at least one disease state relative to recognition of the presence and/or the absence of said biopolymer.
[0031] Although all manner of biomarkers related to all disease conditions are deemed to be within the purview of the instant invention and methodology, particular significance was given to those markers and diseases associated with the complement system and Syndrome X and diseases related thereto.
[0032] The complement system is an important part of non-clonal or innate immunity that collaborates with acquired immunity to destroy invading pathogens and to facilitate the clearance of immune complexes from the system. This system is the major effector of the humoral branch of the immune system, consisting of nearly 30 serum and membrane proteins. The proteins and glycoproteins composing the complement system are synthesized largely by liver hepatocytes. Activation of the complement system involves a sequential enzyme cascade in which the proenzyme product of one step becomes the enzyme catalyst of the next step. Complement activation can occur via two pathways: the classical and the alternative. The classical pathway is commonly initiated by the formation of soluble antigen-antibody complexes or by the binding of antibody to antigen on a suitable target, such as a bacterial cell. The alternative pathway is generally initiated by various cell-surface constituents that are foreign to the host. Each complement component is designated by numerals (C1-C9), by letter symbols, or by trivial names. After a component is activated, the peptide fragments are denoted by small letters. The complement fragments interact with one another to form functional complexes. Ultimately, foreign cells are destroyed through the process of a membrane-attack complex mediated lysis.
[0033] The C4 component of the complement system is involved in the classical activation pathway. It is a glycoprotein containing three polypeptide chains (α, β, and γ). C4 is a substrate of component C1s and is activated when C1s hydrolyzes a small fragment (C4a) from the amino terminus of the α chain, exposing a binding site on the larger fragment (C4b).
[0034] The native C3 component consists of two polypeptide chains, α and β. As a serum protein, C3 is involved in the alternative pathway. Serum C3, which contains an unstable thioester bond, is subject to slow spontaneous hydrolysis into C3a and C3b. The C3f component is involved in the regulation required of the complement system which confines the reaction to designated targets. During the regulation process, C3b is cleaved into two parts: C3bi and C3f. C3bi is a membrane-bound intermediate wherein C3f is a free diffusible (soluble) component.
[0035] Complement components have been implicated in the pathogenesis of several disease conditions. C3 deficiencies have the most severe clinical manifestations, such as recurrent bacterial infections and immune-complex diseases, reflecting the central role of C3. The rapid profusion of C3f moieties and resultant “accidental” lysis of normal cells mediated thereby gives rise to a host of auto-immune reactions. The ability to understand and control these mechanisms, along with their attendant consequences, will enable practitioners to develop both diagnostic and therapeutic avenues by which to thwart these maladies.
[0036] In the course of defining a plurality of disease specific marker sequences, special significance was given to markers which were evidentiary of a particular disease state or with conditions associated with Syndrome-X. Syndrome-X is a multifaceted syndrome, which occurs frequently in the general population. A large segment of the adult population of industrialized countries develops this metabolic syndrome, produced by genetic, hormonal and lifestyle factors such as obesity, physical inactivity and certain nutrient excesses. This disease is characterized by the clustering of insulin resistance and hyperinsulinemia, and is often associated with dyslipidemia (atherogenic plasma lipid profile), essential hypertension, abdominal (visceral) obesity, glucose intolerance or noninsulin-dependent diabetes mellitus and an increased risk of cardiovascular events. Abnormalities of blood coagulation (higher plasminogen activator inhibitor type I and fibrinogen levels), hyperuricemia and microalbuminuria have also been found in metabolic syndrome-X.
[0037] The instant inventors view the Syndrome X continuum in its cardiovascular light, while acknowledging its important metabolic component. The first stage of Syndrome X consists of insulin resistance, abnormal blood lipids (cholesterol and triglycerides), obesity, and high blood pressure (hypertension). Any one of these four first stage conditions signals the start of Syndrome X.
[0038] Each first stage Syndrome X condition risks leading to another. For example, increased insulin production is associated with high blood fat levels, high blood pressure, and obesity. Furthermore, the effects of the first stage conditions are additive; an increase in the number of conditions causes an increase in the risk of developing more serious diseases on the Syndrome X continuum.
[0039] A patient who begins the Syndrome X continuum risks spiraling into a maze of increasingly deadly diseases. The next stages of the Syndrome X continuum lead to overt diabetes, kidney failure, and heart failure, with the possibility of stroke and heart attack at any time. Syndrome X is a dangerous continuum, and preventative medicine is the best defense. Diseases are currently most easily diagnosed in their later stages, but controlling them at a late stage is extremely difficult. Disease prevention is much more effective at an earlier stage.
[0040] Subsequent to the isolation of particular disease state marker sequences as taught by the instant invention, the promulgation of various forms of risk-assessment tests are contemplated which will allow physicians to identify asymptomatic patients before they suffer an irreversible event such as diabetes, kidney failure, and heart failure, and enable effective disease management and preventative medicine. Additionally, the specific diagnostic tests which evolve from this methodology provide a tool for rapidly and accurately diagnosing acute Syndrome X events such as heart attack and stroke, and facilitate treatment.
[0041] Accordingly, it is an objective of the instant invention to define a disease specific marker sequence which is useful in evidencing and categorizing at least one particular disease state.
[0042] It is another objective of the instant invention to evaluate samples containing a plurality of biopolymers for the presence of disease specific marker sequences which evidence a link to at least one specific disease state.
[0043] It is a further objective of the instant invention to elucidate essentially all biopolymeric moieties contained therein, whereby particularly significant moieties may be identified.
[0044] It is a further objective of the instant invention provide at least one purified antibody which is specific to said disease specific marker sequence.
[0045] It is yet another objective of the instant invention to teach a monoclonal antibody which is specific to said disease specific marker sequence.
[0046] It is a still further objective of the invention to teach polyclonal antibodies raised against said disease specific marker.
[0047] It is yet an additional objective of the instant invention to teach a diagnostic kit for determining the presence of said disease specific marker.
[0048] It is a still further objective of the instant invention to teach methods for characterizing disease state based upon the identification of said disease specific marker.
[0049] Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0050] [0050]FIG. 1 is a representation of derived data which characterizes a disease specific marker having a particular sequence useful in evidencing and categorizing at least one particular state;
[0051] [0051]FIG. 2 is the characteristic profile derived via SELDI/TOF MS of the disease specific marker of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0052] Serum samples from individuals were analyzed using Surface Enhanced Laser Desorption Ionization (SELDI) using the Ciphergen PROTEINCHIP system. The chip surfaces included, but were not limited to IMAC-3-Ni, SAX2 surface chemistries, gold chips, and the like.
[0053] Preparatory to the conduction of the SELDI MS procedure, various preparatory steps were carried out in order to maximize the diversity of discernible moities educable from the sample. Utilizing a type of micro-chromatographic column called a C18-ZIPTIP available from the Millipore company, the following preparatory steps were conducted.
[0054] 1. Dilute sera in sample buffer;
[0055] 2. Aspirate and dispense ZIP TIP in 50% Acetonitrile;
[0056] 3. Aspirate and dispense ZIP TIP in Equilibration; solution;
[0057] 4. Aspirate and Dispense in serum sample;
[0058] 5. Aspirate and Dispense ZIP TIP in Wash solution;
[0059] 6. Aspirate and Dispense ZIP TIP in Elution Solution.
[0060] Illustrative of the various buffering compositions useful in the present invention are:
[0061] Sample Buffers (various low pH's): Hydrochloric acid (HCl), Formic acid, Trifluoroacetic acid (TFA),
[0062] Equilibration Buffers (various low pH's): HCl, Formic acid, TFA;
[0063] Wash Buffers (various low pH's): HCl, Formic acid, TFA;
[0064] Elution Solutions (various low pH's and % Solvents): HCl, Formic acid, TFA;
[0065] Solvents: Ethanol,Methanol, Acetonitrile.
[0066] Spotting was then performed, for example upon a Gold Chip in the following manner:
[0067] 1. spot 2 ul of sample onto each spot
[0068] 2. let sample partially dry
[0069] 3. spot 1 ul of matrx, and let air dry.
[0070] HiQ Anion Exchange Mini Column Protocol
[0071] 1. Dilute sera in sample/running buffer;
[0072] 2. Add HiQ resin to column and remove any air bubbles;
[0073] 3. Add Uf water to aid in column packing;
[0074] 4. Add sample/running buffer to equilibrate column;
[0075] 5. Add diluted sera;
[0076] 6. Collect all the flow through fraction in Eppendorf tubes until level is at resin;
[0077] 7. Add sample/running buffer to wash column;
[0078] 8. Add elusion buffer and collect elusion in Eppendorf tubes.
[0079] Illustrative of the various buffering compositions useful in this technique are:
[0080] Sample/Running buffers: including but not limited to Bicine buffers of various molarities, pH's, NaCl content, Bis-Tris buffers of various molarities, pH's, NaCl content, Diethanolamine of various molarities, pH's, NaCl content, Diethylamine of various molarities, pH's, NaCl content, Imidazole of various molarities, pH's, NaCl content, Tricine of various molarities, pH's, NaCl content, Triethanolamine of various molarities, pH's, NaCl content, Tris of various molarities, pH's, NaCl content.
[0081] Elution Buffer: Acetic acid of various molarities, pH's, NaCl content, Citric acid of various molarities, pH's, NaCl content, HEPES of various molarities, pH's, NaCl content, MES of various molarities, pH's, NaCl content, MOPS of various molarities, pH's, NaCl content, PIPES of various molarities, pH's, NaCl content, Lactic acid of various molarities, pH's, NaCl content, Phosphate of various molarities, pH's, NaCl content, Tricine of various molarities, pH's, NaCl content.
[0082] Chelating Sepharose Mini Column
[0083] 1. Dilute Sera in Sample/Running buffer;
[0084] 2. Add Chelating Sepharose slurry to column and allow column to pack;
[0085] 3. Add UF water to the column to aid in packing;
[0086] 4. Add Charging Buffer once water is at the level of the resin surface;
[0087] 5. Add UF water to wash through non bound metal ions once charge buffer washes through;
[0088] 6. Add running buffer to equilibrate column for sample loading;
[0089] 7. Add diluted serum sample;
[0090] 8. Add running buffer to wash unbound protein;
[0091] 9. Add elution buffer and collect elution fractions for analysis;
[0092] 10. Acidify each elution fraction.
[0093] Illustrative of the various buffering compositions useful in this technique are: Sample/Running buffers including but not limited to Sodium Phosphate buffers at various molarities and pH's;
[0094] Charging buffers including but not limited to Nickel Chloride, Nickel Sulphate, Copper II Chloride, Zinc Chloride or any suitable metal ion solution;
[0095] Elution Buffers including but not limited to Sodium phosphate buffers at various molarities and pH's containing various molarities of EDTA and/or Imidazole.
[0096] HiS Cation Exchange Mini Column Protocol
[0097] 1. Dilute sera in sample/running buffer;
[0098] 2. Add HiS resin to column and remove any air bubbles;
[0099] 3. Add Uf water to aid in column packing;
[0100] 4. Add sample/running buffer to equilibrate column for sample loading;
[0101] 5. Add diluted sera to column;
[0102] 6. Collect all flow through fractions in Eppendorf tubes until level is at resin.
[0103] 7. Add sample/running buffer to wash column.
[0104] 8. Add elusion buffer and collect elusion in Eppendorf tubes.
[0105] Illustrative of the various buffering compositions useful in this technique are:
[0106] Sample/Running buffers: including but not limited to Bicine buffers of various molarities, pH's, NaCl content, Bis-Tris buffers of various molarities, pH's, NaCl content, Diethanolamine of various molarities, pH's, NaCl content, Diethylamine of various molarities, pH's, NaCl content, Imidazole of various molarities, pH's, NaCl content, Tricine of various molarities, pH's, NaCl content, Triethanolamine of various molarities, pH's, NaCl content, Tris of various molarities, pH's, NaCl content.
[0107] Elution Buffer: Acetic acid of various molarities, pH's, NaCl content, Citric acid of various molarities, pH's, NaCl content, HEPES of various molarities, pH's, NaCl content, MES of various molarities, pH's, NaCl content, MOPS of various molarities, pH's, NaCl content, PIPES of various molarities, pH's, NaCl content, Lactic acid of various molarities, pH's, NaCl content, Phosphate of various molarities, pH's, NaCl content, Tricine of various molarities, pH's, NaCl content.
[0108] The procedure for profiling serum samples is described below:
[0109] Following the preparatory steps illustrated above, various methods for use of the PROTEINCHIP arrays, available for purchase from Ciphergen Biosystems (Palo Alto, Calif.), may be practiced. Illustrative of one such method is as follows.
[0110] The first step involved treatment of each spot with 20 ml of a solution of 0.5 M EDTA for 5 minutes at room temperature in order to remove any contaminating divalent metal ions from the surface. This was followed by rinsing under a stream of ultra-filtered, deionized water to remove the EDTA. The rinsed surfaces were treated with 20 ml of 100 mM Nickel sulfate solution for 5 minutes at room temperature after which the surface was rinsed under a stream of ultra-filtered, deionized water and allowed to air dry.
[0111] Serum samples (2 ml) were applied to each spot (now “charged” with the metal-Nickel) and the PROTEINCHIP was returned to the plastic container in which it was supplied. A piece of moist KIMWIPE was placed at the bottom of the container to generate a humid atmosphere. The cap on the plastic tube was replaced and the chip allowed to incubate at room temperature for one hour. At the end of the incubation period, the chip was removed from the humid container and washed under a stream of ultra-filtered, deionized water and allowed to air dry. The chip surfaces (spots) were now treated with an energy-absorbing molecule that helps in the ionization of the proteins adhering to the spots for analysis by Mass Spectrometry. The energy-absorbing molecule in this case was sinapinic acid and a saturated solution prepared in 50% acetonitrile and 0.05% TFA was applied (1 ml) to each spot. The solution was allowed to air dry and the chip analyzed immediately using MS (SELDI).
[0112] Serum samples from patients suffering from a variety of disease states were analyzed using one or more protein chip surfaces, e.g. a gold chip or an IMAC nickel chip surface as described above and the profiles were analyzed to discern notable sequences which were deemed in some way evidentiary of at least one disease state.
[0113] In order to purify the disease specific marker and further characterize the sequence thereof, additional processing was performed.
[0114] For example, Serum (20 ml) was (diluted 5-fold with phosphate buffered saline) concentrated by centrifugation through a YM3 MICROCON spin filter (Amicon) for 20 min at 10,000 RPM at 4° C. in a Beckman MICROCENTRIFuge R model bench top centrifuge. The filtrate was discarded and the retained solution, which contained the two peptides of interest, was analyzed further by tandem mass spectrometry to deduce their amino acid sequences. Tandem mass spectrometry was performed at the University of Manitoba's (Winnipeg, Manitoba, Canada) mass spectrometry laboratory using the procedures that are well known to practitioners of the art.
[0115] As a result of these procedures, the disease specific marker identified by the sequence SKITHRIHWESASLL was found. This marker is characterized as a C3f fragment from the complement system having a molecular weight of about 1777 daltons. The characteristic profile of the marker is set forth in FIG. 2. As easily deduced from the data set forth in FIG. 1, this marker is indicative of an individual suffering from myocardial infarction, intracerebral hemorrhage, congestive heart failure or Type II diabetes.
[0116] In accordance with various stated objectives of the invention, the skilled artisan, in possession of the specific disease specific marker as instantly disclosed, would readily carry out known techniques in order to raise purified biochemical materials, e.g. monoclonal and/or polyclonal antibodies, which are useful in the production of methods and devices useful as point-of-care rapid assay diagnostic or risk assessment devices as are known in the art.
[0117] The specific disease markers which are analyzed according to the method of the invention are released into the circulation and may be present in the blood or in any blood product, for example plasma, serum, cytolyzed blood, e.g. by treatment with hypotonic buffer or detergents and dilutions and preparations thereof, and other body fluids, e.g. CSF, saliva, urine, lymph, and the like. The presence of each marker is determined using antibodies specific for each of the markers and detecting specific binding of each antibody to its respective marker. Any suitable direct or indirect assay method may be used to determine the level of each of the specific markers measured according to the invention. The assays may be competitive assays, sandwich assays, and the label may be selected from the group of well-known labels such as radioimmunoassay, fluorescent or chemiluminescence immunoassay, or immunoPCR technology. Extensive discussion of the known immunoassay techniques is not required here since these are known to those of skilled in the art. See Takahashi et al. (Clin Chem 1999;45(8):1307) for S100B assay.
[0118] A monoclonal antibody specific against the disease marker sequence isolated by the present invention may be produced, for example, by the polyethylene glycol (PEG) mediated cell fusion method, in a manner well-known in the art.
[0119] Traditionally, monoclonal antibodies have been made according to fundamental principles laid down by Kohler and Milstein. Mice are immunized with antigens, with or without, adjuvants. The splenocytes are harvested from the spleen for fusion with immortalized hybridoma partners. These are seeded into microtitre plates where they can secrete antibodies into the supernatant that is used for cell culture. To select from the hybridomas that have been plated for the ones that produce antibodies of interest the hybridoma supernatants are usually tested for antibody binding to antigens in an ELISA (enzyme linked immunosorbent assay) assay. The idea is that the wells that contain the hybridoma of interest will contain antibodies that will bind most avidly to the test antigen, usually the immunizing antigen. These wells are then subcloned in limiting dilution fashion to produce monoclonal hybridomas. The selection for the clones of interest is repeated using an ELISA assay to test for antibody binding. Therefore, the principle that has been propagated is that in the production of monoclonal antibodies the hybridomas that produce the most avidly binding antibodies are the ones that are selected from among all the hybridomas that were initially produced. That is to say, the preferred antibody is the one with highest affinity for the antigen of interest.
[0120] There have been many modifications of this procedure such as using whole cells for immunization. In this method, instead of using purified antigens, entire cells are used for immunization. Another modification is the use of cellular ELISA for screening. In this method instead of using purified antigens as the target in the ELISA, fixed cells are used. In addition to ELISA tests, complement mediated cytotoxicity assays have also been used in the screening process. However, antibody-binding assays were used in conjunction with cytotoxicity tests. Thus, despite many modifications, the process of producing monoclonal antibodies relies on antibody binding to the test antigen as an endpoint.
[0121] The purified monoclonal antibody is utilized for immunochemical studies.
[0122] Polyclonal antibody production and purification utilizing one or more animal hosts in a manner well-known in the art can be performed by a skilled artisan.
[0123] Another objective of the present invention is to provide reagents for use in diagnostic assays for the detection of the particularly isolated disease specific marker sequences of the present invention.
[0124] In one mode of this embodiment, the marker sequences of the present invention may be used as antigens in immunoassays for the detection of those individuals suffering from the disease known to be evidenced by said marker sequence. Such assays may include but are not limited to: radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), “sandwich” assays, precipitin reactions, gel diffusion immunodiffusion assay, agglutination assay, fluorescent immunoassays, protein A or G immunoassays and immunoelectrophoresis assays.
[0125] According to the present invention, monoclonal or polyclonal antibodies produced against the disease specific marker sequence of the instant invention are useful in an immunoassay on samples of blood or blood products such as serum, plasma or the like, spinal fluid or other body fluid, e.g. saliva, urine, lymph, and the like, to diagnose patients with the characteristic disease state linked to said marker sequence. The antibodies can be used in any type of immunoassay. This includes both the two-site sandwich assay and the single site immunoassay of the non-competitive type, as well as in traditional competitive binding assays.
[0126] Particularly preferred, for ease and simplicity of detection, and its quantitative nature, is the sandwich or double antibody assay of which a number of variations exist, all of which are contemplated by the present invention. For example, in a typical sandwich assay, unlabeled antibody is immobilized on a solid phase, e.g. microtiter plate, and the sample to be tested is added. After a certain period of incubation to allow formation of an antibody-antigen complex, a second antibody, labeled with a reporter molecule capable of inducing a detectable signal, is added and incubation is continued to allow sufficient time for binding with the antigen at a different site, resulting with a formation of a complex of antibody-antigen-labeled antibody. The presence of the antigen is determined by observation of a signal which may be quantitated by comparison with control samples containing known amounts of antigen.
[0127] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0128] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings/figures.
[0129] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The oligonucleotides, peptides, polypeptides, biologically related compounds, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The instant invention involves the use of a combination of preparatory steps in conjunction with mass spectroscopy and time-of-flight detection procedures to maximize the diversity of biopolymers which are verifiable within a particular sample. The cohort of biopolymers verified within such a sample is then viewed with reference to their ability to evidence at least one particular disease state; thereby enabling a diagnostician to gain the ability to characterize either the presence or absence of said at least one disease state relative to recognition of the presence and/or the absence of said biopolymer.
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[0001] This application claims the benefit of provisional application serial No. 60/244,854 filed Nov. 1, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a method for analyzing or designing extrusion devices utilizing mathematical modeling. Moreover, the present invention relates to a system for analyzing or designing extrusion devices.
BACKGROUND
[0003] The modeling of solid objects is employed in various fields. Such modeling is used, for example, in the simulation of injection molding. In that field, it is widely recognized that the filling and packing phases of injection molding have a significant effect on the visual and mechanical properties of a molded object. Simulation is employed to analyze proposed shapes and injection points, and thus the final quality of the ultimate article. A requirement of any injection mold is that it can be filled with molten polymer given the pressure limits of a real injection molding machine. Simulation can provide information as to whether the mold can be filled and the fill pattern that will be achieved. By using simulation, it is possible to determine optimum gate locations and processing conditions. It is possible to predict the location of weld lines and air traps. Economic benefit is derived from simulation because problems can be predicted and solutions tested prior to the actual creation of the mold. This eliminates costly re-working and decreases the time required to get an object into production.
[0004] Simulation technology has been developed and generally uses finite element/finite difference/finite volume or other techniques to solve the governing equations of fluid flow and heat transfer. In order to minimize the time required for analysis and hence the required computer resources, the Hele-Shaw approximation is invoked to simplify the governing equations. It has been found that this simplification provides sufficient accuracy for injection molding but does create the need for specific modeling of the computational domain.
[0005] Injection molding is an excellent process for repetitively manufacturing large numbers of objects or parts having complicated geometrics. A characteristic of injection molded components is that the thickness of the wall is generally a small fraction of the overall length of the component. In view of the low thermal conductivity of plastics, this physical characteristic is essential to achieve the rapid cycle times that make the process so attractive.
[0006] The flow of melt in an injection mold is determined by the familiar conservation laws of fluid mechanics and the rheological behavior of the injected fluids. Solution of the equations in their full generality presents several practical problems. Owing to the characteristically thin walls of molded components, however, it is possible to make some reasonable assumptions that lead to a simplification of the governing equations. These simplified equations describe what is called Hele-Shaw flow and may be readily solved in complex geometries using an appropriate numerical technique such as the finite element and/or finite difference method.
[0007] Injection molding simulation is now routinely regarded as a desirable aspect of plastic part design. Similarly, improved computer aided drafting (CAD) technology has led to the widespread use of surface and solid modeling. Associated advantages of this are the ability to better visualize an object, to use numerical cutting, and the possibility of achieving more concurrency in engineering design and manufacture. When using the Hele-Shaw approximation, plastic CAE analysis still requires the use of a surface model, representing the midplane of the real component, which is then meshed with triangular or quadrilateral elements to which suitable thicknesses are ascribed. The preparation of such a mesh can take a considerable amount of time, and requires substantial user input; owing to the labor intensive nature of this step, model preparation requires the greatest share of time when performing a molding simulation and makes this technique time consuming. In addition, as model preparation is an interactive task, it has a higher cost associated with it than simply running a computer program.
[0008] One solution to the above shortcomings is to avoid the use of the Hele-Shaw equations and solve the governing equations in their full generality. This has inherent problems owing to the thin walled nature of injection molded objects and parts. To perform such an analysis, the region representing the mold cavity into which molten polymer will be injected must be divided into small sub-domains called elements. Usually these elements are of tetrahedral or hexahedral shape. This process of subdivision is called meshing and the resultant network of tetrahedra or hexahedra is called the mesh. Owing to the complicated shape of many injection molded objects and parts it is generally not possible to automatically mesh the cavity with hexahedral elements. It is possible, however, to mesh the domain automatically with tetrahedral elements. The thin walled nature of injection molded objects and parts means that the plastic is subject to a huge thermal gradient in the thickness direction of the component. This requires that there be a reasonable number of elements through the thickness. Using existing meshing technology, the result is a mesh consisting of hundreds of thousands or even millions of elements. The high number of elements makes the problem intractable for any but the fastest super computers. These are rarely found in industry, being extremely costly to purchase and maintain. Thus, although three dimensional simulation provides a solution that avoids the requirement of a midplane model, it is not as yet a practical solution.
[0009] For example, U.S. Pat. Nos. 6,096,088 and 4,989,166, the entire subject matter of which is incorporated herein by reference, describe processes for modeling fluid flow in molds to design plastic articles prepared therefrom. Modeling of the quench zone in melt spinning polyethylene terephthalate (PET) has also been performed using numerical analysis, Dr. V. M. Nadkarni and Dr. V.S. Patuardhan, Simulation Software For Multifilament Melt Spinning Of PET , International Fiber Journal, December 1999, pp. 64-69. However, this system only models the extrudate or fiber exiting the extrusion device or spinneret pack. Due to the inherent limitations of this system, it would not be suitable for use in the design of the extrusion device itself, only the quench zone (i.e., the portion of the process in which the fiber exits the spinneret pack up to drawing and annealing of the fiber).
[0010] Accordingly, there is a need for a modeling system and process that will accurately simulate an entire plastic extrusion process, which would enable the accurate analysis and/or design of extrusion devices without requiring super computers. Moreover, there is a need for such a system that is easy to use and that is not prohibitively labor intensive.
SUMMARY OF THE INVENTION
[0011] The present invention relates to a method for analyzing or designing a fluid extrusion device using a computer system by inputting fluid rheological data and extrusion device data into the computer system, the computer system having Computational Fluid Dynamics (CFD) numerical algorithms and a user interface, computing flow characteristics of the extrusion device, and extracting data relating to the flow characteristics.
[0012] The present invention also relates to a computer system for analyzing or designing a fluid extrusion device having CFD numerical algorithms and a user interface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other objects, advantages, and features of the present invention will be apparent to those skilled in the art upon reading the following description with reference to the accompanying drawings in which:
[0014] [0014]FIG. 1 is a schematic representing elements of the modeling system according to the present invention;
[0015] [0015]FIG. 2 is a flowchart of the method for modeling the flow through a spinneret pack according to the present invention;
[0016] [0016]FIG. 3 is a schematic representation of a typical spin pack used for bicomponent fiber spinning, and a listing of important physics that occur in the pack and important quantities and phenomena of interest to fiber spinners.
[0017] [0017]FIG. 4 is an exploded view of a spin pack of a particular design (a pack with a melt pool) that illustrates the algorithm used to model the flow in such a pack according to the present invention.
[0018] [0018]FIG. 5 is a flowchart of the method for modeling the flow through a spinneret pack and the subsequent fiber quench device according to the present invention.
[0019] [0019]FIG. 6 is a schematic representation of the filament extrusion and quenching zone, its positional relationship to the pack, and typical modeling results for this zone according to the present invention.
[0020] [0020]FIG. 7 is a representation of quench air flow pattern in the quenching zone.
[0021] [0021]FIG. 8 is a representation of filament crystallinity within the quenching zone chimneys.
[0022] [0022]FIG. 9 is a representation of filament temperature within the quenching zone chimneys.
[0023] [0023]FIG. 10 is a graph representing improvement in filament to filament flow distribution obtained utilizing the present invention.
[0024] [0024]FIG. 1 1 is a flowchart of a conventional fiber development process compared to a design process of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] One embodiment of the present invention relates to a system for modeling the flow of a material through an extrusion device. This simulation allows for the analysis or troubleshooting of existing extrusion devices and/or the design of new extrusion devices without physically modifying or constructing such devices first. This embodiment of the present invention is illustrated by FIG. 1, which depicts a modeling system including computational fluid dynamics (CFD) numerical methods 11 , an interface to a commercial CFD code 12 , a library of utilities 13 , non-CFD numerical and non-numerical methods 14 , a parts database 15 , a rheological analysis system 16 , a materials database 17 and an interface 18 between components 11 - 17 and a user. The CFD numerical methods include finite element, finite difference and finite volume methods, and provide solutions to the mass, energy and momentum transport equations within the device and extrusion zone. The commercial CFD code interface 12 contains a collection of algorithms and functions that integrate the present invention into the commercial CFD code in such a way that the user need not know how to use the commercial code, or even recognize that it is being used. Such commercial code is, for example, CFX4 and is available from AEA Technology plc. The collection of algorithms can include coordinate transformation algorithms, root solving algorithms, sorting algorithms, mesh generation algorithms, various statistical algorithms, curve fitting algorithms, functional minimization algorithms, various interpolation and extrapolation algorithms, and linear and nonlinear equation solving algorithms. The user interface can include functions that prompt the user for appropriate input, issue warnings, display results, and translate user input and algorithm output into readily usable formats.
[0026] The library of utilities 13 consists of a collection of functions that provide integration and user interface capabilities and a variety of other needed capabilities, for example, a Fortran subroutine that manages the opening and closing of data files. The non-CFD numerical and non-numerical methods 14 consists of a collection of numerical and non-numerical algorithms that are used by the system for various purposes. For example, this component contains multiple string manipulation algorithms, subroutine or functions that are used to provide a user-friendly interface. In addition, this component contains mathematical algorithms for performing analytic geometry calculations, root finding and coordinate transformations. The parts database 15 contains complete geometric and material descriptions of the pack components and extrusion zone components. The rheological analysis system 16 contains the algorithms required to analyze raw rheometric data for fluids, generate rheological models, generate tabular and graphical representations of the analysis and data, and enter the information into the materials database 17 . The materials database 17 contains rheological, heat transfer and other properties of the polymers and other materials that are simulated by the system. “Polymer” as used herein may be a polymer, copolymer, terpolymer, oligomer, etc., and may include synthetic and non-synthetic materials. This includes polymers such as nylon-6, nylon 6,6, polyethylene, polypropylene and polyester. The fluid may include additives, fillers, conductive materials, optical modifiers, etc.
[0027] The modeling method and system of the present invention may be utilized in analyzing and designing a variety of extrusion devices, including spinneret packs for producing fibers, and extrusion devices for producing films, molded products, pellets, or strands.
[0028] Another embodiment of the present invention regards a method for analyzing and/or designing an extrusion device utilizing a modeling system of the present invention. An example of this embodiment of the present invention includes the modeling of flow in a spinneret pack 20 and is illustrated by FIG. 2, which includes selecting pack parts from the parts database and/or defining them 21 , selecting fluids from the materials database and/or defining them 22 , defining appropriate operating conditions 23 , construction of the operating curves for individual sections of the pack 24 , solving the appropriate model equations for the pack 25 , and viewing the appropriate results of the modeling 26 . The modeled data can include flowrates through various channels within the pack, pressure drop across various channels within the pack, exit temperatures of various channels within the pack, polymer interface locations at various channel exits within the pack, shear rates and shear stresses at channel walls within the pack, and measures of hydrodynamic instability at various positions within the pack. Construction of the operating curves is accomplished automatically by the computer system. Such a system is intelligent enough to know what channels it must compute operating curves for, for which fluids and over what operating ranges. Furthermore, the system chooses the appropriate CFD methods, executes the CFD calculations, monitors convergence and completion, tabulates results and notifies the user when all calculations are complete. Because of this system intelligence, the user need not have any knowledge of CFD whatsoever to effectively use the system. Solution of the appropriate model equations for the pack is also accomplished automatically, the appropriate methods being chosen by the system. The solution format can cover a wide range, including tables, line graphs and three dimensional animations of pack flow.
[0029] In one embodiment according to the present invention, the modeling system and method may be utilized to analyze or design a spinneret pack. A typical spinneret pack 30 shown in FIG. 3 is composed of filter 31 , one or more distribution plates ( 32 and 33 ) and a spinneret die 34 . Even though FIG. 3 illustrates a bicomponent fiber spinneret pack, it will be appreciated that the present invention may be utilized for the analysis and/or design of spinneret packs for single component fibers or any multi-component fibers. Additionally, any dimensions of the spinneret pack components and die configurations may be employed. The filter 31 may have many forms, such as the open cavity shown in the figure, and contain many and multiple different kinds of filter media, such as metal woven and etched screens, sand, glass, or particulate metal. The purpose of the filter 31 is at least to remove unwanted material from the entering fluid streams, although it may accomplish other purposes as well, such as altering the temperature profile within the fluids. The distribution plates 32 and 33 may have many forms as well, consisting of holes, channels and slots in various combinations, the purpose of which is to distribute the fluids to the spinneret capillaries 35 in the desired proportions. The spinneret is the extrusion die 34 , and is used to form the fibers. The die holes may be any size and shape (i.e., round, multi-lobal, etc.), in principle, and their design can accomplish other objectives beyond controlling filament shape and size, such as controlling stability of the fibers within the quench zone. The spinneret pack may be designed to produce any fiber configuration 36 , including coalescing filaments (i.e., filaments composed of multiple extradate streams, such as hollow filaments), and noncoalescing including, but not limited to sheath core, striped, multi-lobal, eccentric, etc.
[0030] In another embodiment of the present invention, a modeling method and system as described herein are enhanced by assuming that the flow of material through portions (e.g., channels) of the extrusion device is fully developed instantaneously. This flow may be demonstrated by the following expression:
t D /t C =( RE R )/(2 L )<<1
[0031] wherein:
[0032] t D =characteristic time scale for diffusive momentum transport in channel (□ to flow);
[0033] t D =residence time in channel;
[0034] Re=channel Reynolds number;
[0035] R=characteristic dimension of the channel perpendicular to flow, such as radius;
[0036] L=length of channel.
[0037] In other words, the time required for diffusive momentum transport is much less (i.e., less than 1/10) than the residence time in the channel, or said another way, diffusive momentum transport is much faster than convective transport in the channels. This is frequently true for polymeric materials used in fiber spinning, but can be valid for any material in general.
[0038] This assumption provides a modeling system and method that is accurate (i.e., precise to within the limits of what is satisfactory for part design), versatile (i.e., applicable to any extrusion device and with any material), not labor intensive (i.e., avoids the need for the user to generate a separate CFD mesh for every part), and alleviates the requirement of “super” computers (e.g., expensive computers that have high computation speed, memory or parallel (or clusters) of computers) that would normally be needed to obtain acceptable modeling of extrusion devices. Accordingly, this system may be employed with typical or average central processing units.
[0039] In accordance with the present invention, FIG. 4 represents a process 40 for analysis and/or design of a spin pack. In this case, the computer system breaks the pack into its component parts (sand cavity 41 , distribution plate 42 , melt pool 43 and spinneret plate 44 in this example), and applied CFD methods to the solution of the flow in each part of the pack. The solutions to the individual CFD problems at the boundaries (boundary conditions, abbreviated BC in the figure) are matched and the process iterated in the manner shown in the figure until converged solutions are obtained for each pack component. For example, the spin pack problem is broken up into multiple components (as shown in FIG. 4, four components, e.g., sand cavity 4 , distribution plate 42 , melt pool 43 , and spinneret plate 44 ). The combination of the assumption set forth in Equation I and the process of breaking up the problem into easily soluble components, allows for rapid and repetitive solution to the problem with inexpensive computers and no user CFD expertise.
[0040] In another embodiment of the present invention, an entire extrusion process may be modeled using a system and process of the present invention. For example, not only may the extrusion device be modeled, but also subsequent processing of the extrudate may also be modeled. FIG. 5 represents a fiber-forming process 50 (e.g., a polymeric material) including spinning of the fiber and subsequent quenching of the fiber. Fluid is introduced into the pack 51 , as discussed above, extruded through the spinneret plate 52 and introduced into the quench zone 53 . In the quench zone 53 , the filaments 54 are formed, solidified and cooled, and often oriented and crystallized as well. In addition to what is shown in this figure, in typical industrial spinning machines multiple quench zones are operated side by side, the collection of all such zones constituting the spinning machine. All of the zones discharge quench fluid into the region next to the machine. The interaction between the fluid flow in the quench zones and the region next to the spinning machine is important, and should be accounted for in the modeling of fiber formation.
[0041] To this end, FIG. 6 illustrates the process 60 by which the computer system performs fiber forming analysis. The results from the pack analysis calculations 61 are used as input into the fiber forming analysis model 60 . This model 60 consists of three primary CFD calculations, one for the filaments 62 , one for the quench zone 63 and one for the region 64 next to or adjacent to the quench zone. These are solved separately, but the boundary conditions are matched by an iterative process, whereby upon completion the solution is obtained for all filaments, all quench zones and the region adjacent to the chimney. Modeling of multiple spinning machines can be accomplished as well, by appropriate use of symmetry boundary conditions in the adjacent region calculation.
[0042] The modeling of a complete spinning machine using the methods of computational fluid dynamics is an intractable problem, due to the wide disparity in relevant length scales (very small fibers, very large spinning machines) and important physical phenomena, and to the fact that the interaction of the quench zone with the adjacent region is important. It is this approach of breaking the problem up into three separate CFD problems (filaments, quench zones, adjacent region) and iteratively matching these solutions together that makes the problem tractable with modest computer resources and no knowledge of CFD on the part of the user.
[0043] FIGS. 7 - 9 illustrate the kind of information that can be obtained from a filament formation model. FIG. 7 shows a simulation 70 in a fiber forming process. The downward drag of the filaments on the quench air is evident from the quench air streamlines 72 . This includes but is not limited to fluid streamlines 72 (that is, quench air flow pattern) within the quench chimney, and filament properties such as temperature and crystallinity (for semicrystalline and crystalline materials) for every filament within every chimney. FIG. 8 represents crystallinity 81 from the spinneret face 82 to the bottom of the chimneys 83 throughout bunches of filaments 84 - 87 in four consecutive chimneys of a fiber spinning machine. The filament information can be plotted as a distribution, which is helpful for optimizing existing designs and generating new designs. FIG. 9 illustrates filament to filament variability with regard to certain properties (e.g., filament speed 91 and filament temperature 92 ) at the bottom of a chimney. The filaments exiting the spinneret face 93 are exposed to quench air 94 penetrating the filament's bundle. As is readily apparent, region A is quenched much more effectively than region B, which is illustrated by the higher filament speed ( 91 A) and lower filaments temperature ( 92 A).
[0044] [0044]FIG. 10 shows a typical improvement in filament to filament distribution 100 that is obtained using the computer system of the present invention. The system first predicts the upper distribution 101 , which is poor because there is an unacceptable difference in throughput from one filament to the next, then allows the user to easily redesign the pack components (e.g., the distribution plate and/or the spinneret plate) in order to obtain the lower distribution 102 , which is excellent, in that very little variation in throughput from filament to filament exists.
[0045] [0045]FIG. 1 1 shows the impact that the use of the system on the fiber development process. According to traditional fiber development processes 110 of the present invention imparts, proper design of pack parts is an iterative process 111 , requiring significant expenditure in experimental, pilot plant and/or plant trials. In the fiber development processes with this computer system 112 , the pack part design iteration is eliminated—pack parts can be designed right the first time.
[0046] As is readily apparent from the description of the present invention, the benefits of this computer system include 1) simple user interface that permits wide use of the system, 2) high quality numerical methods and fluid mechanical models that provide accurate answers, 3) highly integrated system that allows the user to perform a wide variety of realistic analyses and designs with little effort, 4) parts and material databases that allow users to select pack and quench hardware components with little effort, 5) judicious use of sound physical assumptions that permit repeated use of the system without requiring the user to generate or even know anything about CFD, and without requiring enormous computational resources.
[0047] All of the devices and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the devices and methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are chemically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.
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A method for analyzing or designing a fluid extrusion device using a computer system involves inputting fluid rheological data and extrusion device data into a computer system having CFD numerical algorithms and a user interface; computing flow characteristics of the extrusion device; and extracting data relating to the flow characteristics.
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BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to an improved spinning pot used for twisting and winding synthetic textile yarns. The "SPINNING POTS" are used for high speed spinning of yarn in textile industries in general and viscose yarn industries in particular.
2. Description of the Prior Art
As per known art, the spinning pots have been used for decades in large or small textile mills. The known pot forms a unitary construction or a cylindrical portion and the base plate therefor. It is mounted on a pot motor with its rotating axis vertical and driven at high speeds of rotation, typically 8000 rpm. Textile yarn filaments coming out of spinnerettes are directed through a funnel, to initially drop to the centre of the bottom surface of the pot where they are thrown outwards to the wall of the spinning pot by the centrifugal force due to high speed rotation of the pot. A periodic reciprocating motion, given to the funnel along the axis of the pot, winds the spun filament yarn into a helically wound `cake` which builds up uniformly along the internal wall of the spinning pot. The acidic liquid which is picked up by the yarn when it comes out of the coagulating bath is, to a large extent, removed from the `cake` by centrifugal action and thrown out through vent holes on the walls of the spinning pot.
The known spinning pot consists of a barrel having an integral base which is mounted on the shaft of a pot motor by means of a locating bush. There is also provided the usual air vent, acid vent and centre spot. The walls of the barrel of the pot have a plurality of stiffening reinforcements. The pot at the top has a lid, with a locking ring therefor. A funnel and funnel holder are fixed in the said lid for the admission of the yarn. The twisted yarn forms a cake on the inside of the pot.
All known pots now in use are essentially similar in shape and construction. The differences are generally limited to the type of central mounting bush, type of vent holes for excess acid or air, type of reinforcement to make the wall stiffer, type of closure at the top and its retention etc.
Thus, in order to make use of the known pots with the existing components involves the following sequence of steps in its operation:
(i) remove the entire spinning pot from the motor shaft;
(ii) remove locking ring;
(iii) remove lid;
(iv) turn pot upside down;
(v) lightly tap on a soft smooth surface and remove cake.
For starting the cycle of operation, the same sequence in reverse order has to be gone through.
When we consider that the cycle of operation is repeated by thousands of operators millions of times all over the world, saving in operator fatigue and production time is of great importance.
The drawbacks of the hitherto known spinning pots are:
The spinning pot is a highly stressed component which is subjected to cyclic loading of continuous duty;
All existing pots have the common drawback of high stress concentrations at the corner where the cylindrical wall meets the flat circular base;
Also the barrel portion of the vessel which is stressed to the highest level by the centrifugal force exerted by the wet cake, tends to expand into a large cylinder. But the flat circular bottom disc cannot expand equally. This leads to high flexural and shear stresses at the junction of the barrel and its flat circular base;
Furthermore, the base of the pot has large mass of costly acid resistant material which is discarded along with the condemned pots;
The bronze metal bush which is critically precision machined after fixing to the pot is of considerable cost and it is also discarded everytime a pot's life is over. Although the metal can be recovered, the recovery value is a minute fraction of the original cost;
The locating bore and face, being small in dimension have to be very accurate to have the pot run concentrically and in dynamic balance. Even small amount of wear in the bore tends to offset the concentricity and balance of the pot, leading to costly repair work of,
(i) rebushing the pot and
(ii) re-balancing of the pot dynamically;
The existing pots typically weigh about 2 to 3 times the weight of the cake that is formed by spinning. As the operator takes out the entire pot to remove the cake for further processing, it means that the operator handles 2 to 3 times excess load twice for every cake for yarn produced. Although this looks trivial, it is of enormous magnitude, when one considers the total volume of production which runs into thousands of tons per day, affecting thousands of workers, who have to work in continuous exposure to acid fumes in the spinning section of the mill;
The existing pots also consume work energy for the following reasons:
(i) As the weight of the pot is high, the power for accelerating it to the top speed is high;
(ii) As the shape is such that both outer and inner contours cannot be given very smooth surfaces, the practice is to mould the inner surfaces to mirror finish and machine the outer contour by turning and polishing it by sanding;
(iii) As most of the energy consumed during the spinning is for overcoming the aerodynamic friction which is related to the smoothness of the surfaces and accuracy of concentric rotation, mirror smooth finish on all surfaces of the pot will result in substantial saving in energy consumption. As millions of spindles are in operation all over the world on continuous duty, the saving potential is enormous.
SUMMARY OF THE INVENTION
The main object of the invention is to eliminate the stress concentration and high levels of flexural and shear stresses at the corner junction between the barrel and disc portions of the spinning pot.
The other objects of this invention are to:
(i) improve the surface finish and concentricity of all rotating surfaces;
(ii) reduce the weight of the expandable portion of the pot;
(iii) improve the locating arrangement;
(iv) reduce the cost of manufacture of the pots;
(v) reduce the cost of raw materials used in the manufacture of the pots;
(vi) reduce the energy consumption in the use of the pots in a textile mill;
(vii) improve the safety of the pot by controlling failure mode;
(viii) reduce operator fatigue.
The basic principle of the invention is to isolate the two areas of stress levels by having the pot as a near cylindrical vessel with both ends open and removably attached to the base plate.
The novel results thus achieved in this invention are:
(i) improved surface finish and concentricity of the critical part, the conical cylinder (or barrel minus the base) which is an open nearly cylindrical tube lends itself to a high finish on all concentric surfaces, without much difficulty;
(ii) the conical cylinder can be made of considerably less weight than that of the known pots;
(iii) the location of the conical cylinder on a spigot through large locating surfaces result in more precise alignment of the axes of rotation;
(iv) cost of manufacture is reduced very much as the parts are simpler to manufacture and it is easier to control their quality;
(v) cost of raw materials is also reduced as the critically stressed component, namely the conical cylinder only is to be made of costly material;
(vi) energy consumption is reduced due to less weight and better surface finish;
(vii) operator safety is increased because the stress concentrations are reduced and failure mode is controlled;
(viii) operator fatigue is reduced as he has to handle reduced weight per working cycle.
Accordingly this invention provides an improved spinning pot used for twisting and winding synthetic textile yarns which comprises a barrel, with both top and bottom ends open, said barrel being removably mounted on a rotatable base plate by means of a locating spigot means; as said base plate having a locating bush made of two parts consisting of a fixed bush portion integral to the said base plate and a removable bush portion on said fixed bush portion. Spinning pot is fixed on the spindle of a high speed motor by means of said locating bush.
The assembly of the barrel and the base plate is fixed on the spindle of a high speed motor by means of the said locating bush.
According to another feature of the invention the barrel is in the form of a conical cylinder which is provided with stiffening reinforcements to withstand stress exerted by the centrifugal force due to expansion of barrel during operation, said reinforcement being independent of the flat circular bottom disc, and has a concentric locating step for the lid with a groove for a locking ring therefor.
According to still another feature of the invention a locking means are provided for locking the barrel to the base plate at the spigot.
According to a further feature of the invention the locking means consist of a plurality of fingers within the base plate and an annular groove therefor on the conical cylinder bottom portion of the barrel.
According to still another feature of the invention the spigot is in the form of a tapered or cylindrical cross-section to form the joint between the barrel and the base plate.
The removable bush portion can be disposed of due to wear and tear and replaced by a new portion for easy repairs thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a known spinning pot;
FIG. 2 illustrates a spinning pot according to an embodiment of this invention;
FIG. 3 is sectional view of a part of the spinning pot shown in FIG. 2;
FIG. 4 shows locating spigot means for mounting the pot to a base.
DETAILED DESCRIPTION
Referring to FIG. 1, a spinning pot consist of a barrel 10 having an integral base 6 mounted on shaft 3 of a pot motor 1, with a skirt 2, by means of a locating bush 5. It has the usual air vent 4, acid vent 7 and centre spot 8. The walls of the barrel 10 have a plurality of stiffening reinforcements 11. Lid 12 at the top of barrel 10 has a locking ring 13 and is provided with a funnel 15 and funnel holder 14. The funnel 15 is for admission of the yarn. Twisted yarn in the pot forms a Cake 9 on the inside of the pot.
As stated above, in the pot of this invention, as shown in FIGS. 2 through 4, the pot comprising the barrel is a conical cylinder 17 with both top and bottom ends open and top fitted with a lid 12 and locking ring 13. Funnel 15 and funnel holder 14 are in the lid 12. The barrel 17 is removably mounted on a rotatable base 25 by means of a locating spigot means 20, more clearly seen in FIG. 4. A locating bush comprising of a fixed bush portion 19 is integrally formed with the base 25. A removable bush portion 16 is mounted on the integral bush 19. Base 25 has a centre spot 8, as usual.
In place of tapered spigot 20 as shown, a cylindrical spigot may be used.
The separation of the barrel from the base by the combination of the parts to form the pot results in the elimination of high stresses at the joint between the barrel and the base.
The conical cylinder (17) of the improved pot is free to expand under hoop stress developed as a result of the centrifugal force exerted by the cake (9) during high speed rotation. Since this is not rigidly attached to the base, the latter is subjected to a much lower load and thus there is no stress concentration.
Essentially the functions of the new parts are same as those of the known device, namely, the twisting and winding of the yarn. The innovation results in a more reliable, less expensive and safer apparatus.
In the constructional detail the base (25) is mounted on the shaft (3) of pot motor (1) accurately concentric to the axis of rotation. The conical cylinder (17) is located on the base accurately concentric by engagement with the spigot (20). The rotation of the motor shaft (3) is transmitted to the conical cylinder (17) through the base (25) and the whole assembly is rotated at high speed to start the working cycle.
The untwisted bundle of fibres is directed through the funnel (15) on to the centre spot (8) on the base where the fibre bundle is thrown outwards radially to the wall of the conical cylinder (17) by the centrifugal action of the rotating mass. The funnel (15) is given a reciprocating to and fro motion along the axis of rotation, thus forming the fibres into a wound cake (9).
In use, the spigot is mounted on the spindle of the pot motor on a semi-permanent basis. It will normally be necessary to remove it only for (i) resurfacing of the protective layer and/or (ii) replacing of the bush.
The conical cylinder (17), being nearly cylindrical in shape with a slight taper for release of the cake of yarn (9), is moulded from suitable acid resistant-plastic materials with directional reinforcement. The lid (12) is a circular disc of acid resistant plastic. The locking ring (13) is a plastic or rubber ring of suitable acid resistance.
The driving spigot 20 is moulded from similar material as the barrel but without directional reinforcement. The protective layer may be of PTFE (TEFLON) polyurathane or similar hard wearing, acid and abrasion resistant material in the form of a film which is adhesively bonded to the top surface of the spigot.
The base (25) is moulded from similar material as the conical cylinder (17) but does not need directional reinforcement. The base (25) consists of the following: the top surface which is highly polished and flat with a thin protective layer of a suitable film typically polyester, PTFE (TEFLON), polyurethene etc. The centre spot 8 of moulded plastic of contrasting colour is fixed concentric to the locating spigot (20) in a recess at the centre of the top surface. The locating bush 19 is a phospher bronze or similar wear resistant bearing material and has a precisely machined bore which is concentric to the locating (driving) spigot (20). The removable bush (16) is a closely fitting sleeve of similar material to the locating bush (19). The removable bush is accurately machined such that when fitted into the locating bush 19 the bore of the removable bush (16) is concentric to the locating spigot (20).
In use, the base (25) is mounted on the motor shaft (3) of the pot motor (2), on a semipermanent basis. It will normally be necessary to remove it only for (i) resurfacing of the protective layer and/or (ii) replacing the removable bush (16).
The locating spigot (20) in the base (25) has a cylindrical (or slightly conical) step and a square face which together are the locating reference surfaces to locate the conical cylinder (17) accurately concentric to the axis as defined by the motor shaft (3).
The conical cylinder (17) is a precision moulded, smooth surfaced, hollow cylinder with close fitting circular locating diameter at the bottom with a corresponding square face which together when fixed to the locating spigot (20) ensure concentricity of rotation.
The locating spigot (20) may be of two closely fitting conical surfaces instead of cylindrical surfaces for easy assembly and removal.
The lid (12), locking ring (13) etc. are of conventional design and are not relevant to this invention.
When in operation, the high speed rotation of the pot exerts a centrifugal hoop stress on the conical cylinder (17) due to (i) its own mass rotating at high angular velocity, and (ii) the slowly forming wet formed cake (9) of yarn. While (i) is constant during most of the cycle of operation, (ii) increases as the mass of the cake increases to a maximum value when the cycle is completed and the rotation stopped. During this cycle of increasing hoop stress, the conical cylinder (17) is free to expand concentrically without affecting the dynamic balance of the whole system. This results in elimination of regions of abrupt stress changes.
At the end of the cycle, the conical cylinder (17) along with the fully formed cake (9), lid (12), and locking ring (13) is removed from the base (25) and the cake (9) is released by a light tap against a soft, smooth surface. This releasing operation involves only lifting and lateral movement.
The locating spigot 20 has a cylindrical step and a square surface which are accurately concentric and square to the rotating axis as defined by the bush/pot motor spindle.
The barrel (conical cylinder) 17 is a precision moulded smooth surfaced hollow cylinder with close fitting circular locating diameter at the bottom with a corresponding square face which together when kept on the spigot ensure that the axis of the barrel will be accurately aligned with the rotating axis.
The locating spigot 20 may be made of two closely fitting conical surfaces instead of cylindrical surfaces for easy assembly and removal.
The lid, locking ring etc. are of conventional design and not relevant to this invention.
When in operation the high speed rotation of the pot exerts a centrifugal hoop stress on the barrel due to (i) its own mass rotating at high angular velocity and (ii) the slowly forming mass of the partially wet cake of yarn. While (i) is constant during most of the cycle of operation, (ii) increases as the mass of the cake increases to a maximum value when the cycle is completed and the rotation stopped. During this cycle of increasing stress the barrel is allowed to expand freely and concentrically without effecting the dynamic balance. As there is no region of abruptly changing stresses, the critical stress concentration, high flexural/shear stresses mentioned above are non-existant in this invention.
At the end of the cycle the barrel 17 along with the fully formed cake 9, lid 12 and locking ring 13 is removed from the spigot 20 and a light tap against a smooth, soft surface releases the cake. The barrel 17 is again put on the spigot 20 to start the next cycle of operation.
The direct new results exclusively flowing from the spinning pot of this invention are:
(i) elimination of concentration of stress and resultant high stress areas in the spinning pot;
(ii) simplified manufacturing process, typically by a factor of 10 in terms of man-machine hours;
(iii) reduction in materials used, typically by a factor of 2 in terms of cost;
(iv) reduction in weight of the pot, typically by a factor of 2;
(v) reduction in aerodynamic drag, typically by 25% leading to reduction in power consumption, which will have to be worked on the basis of extensive trials;
(vi) reduction in operator fatigue due to reduction in weight handled per cycle;
(vii) increase in plant safety because of elimination of stress concentration and high levels of stresses in operation;
(viii) longer life at lesser cost for the pots because of points listed above.
Directly as a result of the invention, the following modifications to the spinning mill equipment will lead to overall improvements of considerable magnitude:
(i) The base (Ref. FIG. 1) will be of simple moulded plastic with the precision locating bush fitted and bored accurately.
(ii) As only the metallic bush is a wearing component this could be made as a replaceable component in such a way that a readymade square could be fitted to replace a worn out bush, without subsequent boring, balancing, etc. (see FIG. 3).
(iii) The top surface of the base disc which is subject to erosion due to impingement of acid and fibre, is protected by a wear resistant, smooth layer of thin plastic film, which is bonded with a suitable adhesive in such a way that when it has become rough in course of time, the layer is removed by a suitable solvent and a fresh layer bonded again. This leads to very long life of the base.
The conical cylinder (17) being open at both ends is amenable to simpler and more accurate methods of manufacture as well as better surface smoothness on internal as well as external surfaces.
The base (25) also is of simpler design and being a low stress part, is capable of being made from cheaper materials in more productive methods of manufacture.
The accurate location of the conical cylinder (17) to the base (25) through the locating spigot (20) of large reference surfaces makes it very simple to get proper concentricity and dynamic balance.
As the base (25) is generally left fixed on the motor shaft (3) there is less chance of inaccuracies of location due to mishandling.
The removable bush (16) is the only wearing part and is made such that it is very cheap and economical to replace compared to the conventional cost of rebushing.
The barrel is made of high strength unidirectional fibres reinforced with plastic resin.
The high strength fibre used can be glass fibres, carbon fibre, basalt, graphite fibre, boron fibre, organic fibres like `KEVLAR`, natural fibres like asbestos, cotton, jute or sisal either alone or in combination thereof.
The resin used may be phenolic, polyester epoxy, silicone, or similar acid resistant thermosetting plastic. The barrel is thus made by filament winding of fibres.
The fibrous reinforcements of the barrel are impregnated with the resins either before winding or after winding by resin injection.
The barrel is made by moulding of macerated cloth impregnated with plastic resin and is further reinforced with high tensile stainless or other steel wire coiled and placed concentrically in the middle of the cylindrical wall of the barrel.
The high tensile strength is due to the use of carbon, graphite, boron or organic fibre (KEVLAR).
The cylindrical wall of the barrel has plurality of holes to allow the acidic residue to be thrown out by the centrifugal action of the spinning pot.
The locking mechanism may consist of a groove in the barrel portion of the spigot 20 and plurality of fingers in the base disc. These fingers, are fixed to the base disc in such a way that normally, when the pot is at rest they do not project into the spigot groove in the barrel. When the pot rotates at high speed the free ends of the fingers move radially outwards into the corresponding groove in the barrel, thus preventing the barrel from lifting off with respect to the base disc. This locking is automatically out of action when the pot is at rest due to the spring back of the fingers which are fixed at one end only. Therefore fixing or removing the barrel while at rest is not affected in any way.
The locking mechanism may have spring loaded pins instead of the fingers.
The base disc of the pot is made by compression moulding suitable acid resistant materials or by injection moulding of glass filled thermoplastic materials like nylon, acetol, polycarbonate or polypropylene.
The base disc may have a layer of thin, smooth and acid resistant plastic film bonded to the top with a suitable adhesive which could be removed by solvent removal of the said adhesive.
The plastic film layer is of polyester, polypropylene, polyethelene, PTFE or such materials.
The adhesive used may be a hot salt thermoplastic, or a pressure sensitives elastomeric or any other polymeric adhesive like epoxides.
The base disc also has a disposable bush at the centre, which is accurately concentric to the spigot and the same gets its accurate location by being fitted into a close fitting bush which is integral with the base disc.
The integral bush is moulded as an insert and fine bored accurately concentric with respect to the spigot and is fitted into a moulded central cavity by adhesive bonding and then fine bored.
The disposable bush may be made of metallic materials, typically phospor bronze or of low friction non-metallic materials, typically PTFE.
The integral bush may be made of metallic materials, typically aluminium or of non-metallic materials, typically cloth laminated phenolin.
The external surface of the barrel as well as the internal surface are both made concentric to each other and to the spigot as also the axis of rotation. The surface finish of the barrel in new condition would be of mirror finish smoothness.
The concentricity of the pot is achieved by winding of the resin impregnated fibrous materials over a smooth mandrel and closing with an external mould with suitable smooth surface. The external mould will be located accurately concentric to the mandrel by means of locating diameters at both ends.
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In known spinning pots the barrel has an integral base and while the barrel portion may withstand stresses caused by centrifugal forces exerted by the wet cake expanding, the flat bottom base is unable to do so. When discarding the pot, the base also has to be discarded. The present invention provides a spinning pot in which the base is formed separate from a cylindrical barrel and the two are connected by a locating driving spigot. Additionally the base is provided with a bushing in two parts, the wearing part is removably fitted on the main part which is integral with the base.
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FIELD OF THE INVENTION
This invention is in the field of blast joints suitable for service in production zones where the joint will be subjected to high speed particle impingement.
BACKGROUND OF THE INVENTION
In the drilling and production of oil and gas wells, it is frequently necessary to penetrate one or more production zones to reach an underlying zone with production tubing. Each production zone is served by its own string of production tubing which then must penetrate the overlying production zones to reach the surface. At the point where each string of production tubing penetrates an overlying production zone, the tubing can be subjected to severe erosion.
Particularly where the production zone being penetrated produces high pressure gas, abrasive materials entrained in the gas can quickly erode the surface of the production tubing penetrating that zone. High pressure gas moves at very high velocities when the zone is producing and it can contain such entrained erosive materials as grains of sand or drops of liquid. Where the high velocity gas enters the well bore, it impinges upon the penetrating production tubing from an underlying zone and, depending upon the material from which production tubing is made, the high velocity gas can quickly damage or even penetrate the wall of the production tubing.
When the wall of the production tubing has been penetrated in an overlying zone, communication is established between two different production zones through the failed production tubing string. Communication between zones can be highly undesirable, and isolation between the zones must be maintained. Isolation between the zones in the well bore is generally obtained by the use of packers about the production tubing between production zones. When erosion of production tubing has reached an advanced state, it becomes necessary to replace the eroded section or sections of tubing. This requires removing the production tubing string from the well bore, replacing the failed joints of tubing and reinserting the tubing string into the well bore along with any necessary replacement of packers.
Different tubing materials will erode at different rates and to different degrees depending upon the velocity of the impinging fluid as well as the type and amount of abrasive materials entrained in the fluid. Some materials are considered highly erosion resistant, and various methods have been used to incorporate these materials into the design of the production tubing where the tubing must penetrate overlying production zones. Joints of pipe or tubing have been designed which incorporate a jacket of a highly erosion resistant material, such as tungsten carbide, over the production tubing. Various methods are used to insure that the tungsten carbide will surround the tubing at the areas where the high velocity fluid enters the well bore. The tungsten carbide is generally installed in stacks of relatively short rings and held in place longitudinally by various types of sleeves and collars. In some designs, the rings are kept pressed together by the installation of a spring, such as a coil spring, around the tubing to press against the end of one of the tungsten carbide rings.
A major problem with the use of a highly erosion resistant material, such as tungsten carbide, is that such materials, while being very hard, are also very brittle and therefore subject to damage when placed under radial or axial loads. When making up a tubing string for insertion into a well, it is necessary to support the top joint of the string at the well head and to hold that joint against rotation while threading the next joint to the top joint of the string. Power tongs or similar tools are normally used to thread the two joints together. The top joint of the tubing string is held against rotation while the power tongs rotate the next joint being installed. Such power equipment necessarily bites into the surface of the tubing joint in order to apply the necessary torque to either hold the joint against rotation or to rotate the joint in making up the thread. If such power tools are used on a surface of the blast joint where the erosion resistant material, such as tungsten carbide, is exposed, the torque is not efficiently transferred to the tubing and the tungsten carbide rings can easily become chipped and cracked, resulting in a loss of protection against abrasion once placed into service in a production zone.
Another operation frequently encountered which can result in damage to the tungsten carbide rings is the gripping of a blast joint from above with pipe slips having upwardly canted internal teeth. These teeth must necessarily dig into the surface of the joint to achieve their gripping action in order to pull the blast joint or other piece of equipment out of the well bore. Gripping of a blast joint by such a slip, if the slip teeth contact the tungsten carbide rings, can result in cracking or breaking of the rings as mentioned before in the case of power tongs, by the application of radial or axial forces, through the slip teeth.
Some blast joints, using tungsten carbide rings, incorporate thin metal sleeves on the outside of the tungsten carbide rings, but these sleeves are of insufficient strength to withstand the radial and axial stresses imparted by power tools, and the sleeves typically are not mounted to the inner production tubing with sufficient mechanical strength to transfer the necessary torque or axial force to the tubing itself. These thin sleeves are generally only effective at protecting the tungsten carbide rings during assembly and handling which does not involve the use of the aforementioned power tools.
Another disadvantage of blast joints having exterior carbide rings occurs when the operator wishes to insert the blast joint through a snubber unit. A snubber unit allows a pressurized well to be reworked without first plugging or killing the well. Killing the well is undesirable because it can be difficult and expensive to resume production from a well that has been killed. The snubber unit is mounted on the wellhead of a well which is to be reworked under pressure. The snubber unit establishes and maintains a pressure seal around the tubular goods coming out of or going into the well at the wellhead. It is typically mounted atop one or more blowout preventers. In addition to maintaining the pressure seal, the snubber unit grips any tubular goods being inserted and forces them into the well against the wellhead pressure, which can approach several thousand pounds per square inch. Alternatively, the snubber unit can be used to grip a tubular good being extracted from the well to limit or control its outward movement under wellhead pressure.
This gripping of the tubular goods can be accomplished by pipe slips or other devices which place highly concentrated mechanical loads on the goods being gripped. In addition, the pressure seal can only be effective if applied to a relatively smooth surface which is capable of maintaining its pressure integrity under the pressures experienced at the wellhead. It can be seen, then, that a typical carbide blast joint cannot be inserted into a well with a snubber unit. If this were attempted, the carbide rings would immediately deteriorate or even fail completely, and the pressure seal could not be maintained. A very expensive and dangerous blowout would occur.
U.S. Pat. No. 5,016,921 discloses a blast joint which can be handled as a normal section of production tubing using power tongs, pipe slips, or other power equipment and which can also be used with a snubber unit. The blast joint has a continuous protective sheath of tungsten carbide rings mounted on a specially machined pipe joint. The specially machined pipe joint onto which the carbide rings are mounted adds to the cost and time required to fabricate the blast joints.
A further problem often encountered is a sanded-up well having a blast joint with exterior tungsten carbide rings resting against the wall of the well bore. Typically, a washover assembly having a milling shoe made up on the bottom joint of a washover pipe is lowered into the borehead around the production tubing. The milling shoe is rotated to cut away the obstruction. However, the milling shoe is not capable of cutting through tungsten carbide rings if they are in contact with the wall of the well bore. Thus, it may not be possible to remove the obstruction which may result in the well being shut in and a new well drilled.
It is desirable to design a blast joint which can be fabricated from a standard oilfield pipe joint and which provides protection against erosion for its full length without any gaps. It is further desirable that the blast joint can be handled by the use of power tongs and pipe slips without any unusual degradation of the blast joint and also be used with a snubber unit. It is further desirable to design such a blast joint which can be threaded into place in a production tubing string as if it were simply another joint of production tubing, either as a single joint or as a string of consecutive joints having a continuous protective sheath of tungsten carbide rings without any gaps in between. Additionally, it is further desirable to design such a blast joint which will maintain the erosion resistant rings away from the wall of the well bore.
SUMMARY OF THE PRESENT INVENTION
This invention is a blast joint which can be fabricated from a standard oilfield pipe joint and which provides protection against erosion for its full length without any gaps. The standard oilfield pipe joint minimizes cost and time delays inherent is using specially machined pipe joints. The blast joint exhibits a continuous protective sheath of erosion resistant material for essentially its full length.
The lower end of the blast joint of this invention can be handled using power tongs and provides erosion resistance by using overlapping stacks of erosion resistant rings for its full length. The lower end of the blast joint includes a die driver assembly which mounts to the inner pipe joint with sufficient mechanical strength to transfer the necessary torque or axial force to the inner pipe joint itself. The die driver assembly is mounted to the inner pipe joint utilizing a plurality of dies and wedges. A drive ring forces the wedges against the dies which in turn are driven into the outer surface of the inner pipe joint.
This invention further includes a master assembly at the upper end of the blast joint which incorporates a torque tube suitable for gripping with slip teeth and power tongs. The master assembly is mounted on the inner pipe joint in order to impart thereto the axial and radial loads and torque as required to make up the blast joint of this invention with adjacent tubing joints or blast joints.
The invention further includes a pressure operated piston assembly for maintaining zero clearance between a continuous stack of erosion resistant rings by utilizing the downhole well pressure.
Additionally, the invention further includes a snubbing sleeve which is adapted to connect to the lower end of the torque tube. The snubbing sleeve provides a continuous uniform surface which can be gripped by a snubber unit without gripping or damaging the erosion resistant rings. Centralizer ribs attached to the periphery of the snubbing sleeve and torque tube maintain the erosion resistant rings out of direct contact with the wall of the well bore.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention can be had when the following detailed description of the preferred embodiment is considered in conjunction with the following drawings, in which:
FIGS. 1a-1d are partial cross-sections of the blast joint of the present invention arranged in end-to-end relationship with FIG. 1a showing the upper end and FIG. 1-d the lower end of the blast joint;
FIG. 2 is an enlarged partial cross-section of the loader piston and cylinder assembly of the upper assembly as shown in FIG. 1a;
FIG. 3 is an enlarged partial cross-section of the attachment of the snubbing sleeve of the master assembly as shown in FIG. 1b;
FIG. 4 is an enlarged partial cross-section of the die, wedge, backup ring, drive ring and die driver as shown in FIG. 1c;
FIG. 5 is a view taken along line 5--5 of FIG. 4;
FIG. 6 is a bottom view of the die; and
FIG. 7 is an end view of the die.
DETAILED DESCRIPTION OF THE INVENTION
A detailed description of the preferred embodiment of the invention will now be given, illustrated in the drawings as applied to a standard type of pipe joint having a uniform outside diameter along the length of the pipe joint, although the invention may also be utilized with upset pipe joints having portions of increased outside diameter, typically at the ends of the pipe joint. It will be understood that this pipe or tubing joint.
It is also to be understood that FIGS. 1a-1d are continuous sections of the blast joint of the present invention arranged in end-to-end relationship with FIG. 1a showing the upper end and FIG. 1d showing the lower end of the blast joint, and with FIGS. 1b and 1c being upper and lower intermediate sections, respectively.
As shown in FIGS. 1a-1d, a blast joint, designated generally as 100, incorporates at its innermost diameter an inner pipe joint 102 having an upper threaded pin end 104 (FIG. 1a) and a lower threaded pin end 106 (FIG. 1d). Blast protection of this pipe joint 102 is achieved by applying a protective sheath of erosion resistant rings, designated generally as 500, made of a hard material such as tungsten carbide. The erosion resistant rings 500 are arranged in vertical stacks concentric with the inner pipe joint 102 such that successive stacks overlap one another at their ends as shown in FIGS. 1a-1d. The stacks of rings 500 are protected against damage during the handling of the blast joint 100 with various outer housings and assemblies which will be described below.
Referring to FIG. 1a, the upper portion of the blast joint 100 includes a master assembly 200 composed mainly of a master coupling 210 and a torque tube 220. The master coupling 210 includes a through bore 211 having lower internal threads 212 and upper internal threads 214. The lower internal threads 212 engage the upper threaded pin 104 of the blast joint 100. The upper internal threads 214 are provided to join the blast joint 100 with the next uppermost joint of pipe or another blast joint 100. Attached to the lower end of the master coupling 210 is the torque tube 220 which extends downwardly around, and spaced outwardly from, the inner pipe joint 102. The lower end of the master coupling 210 also includes an external threaded portion 216. Threadably attached to the lower end of the master coupling 210 is a top tube 252 of a top housing 250. The top tube 252 extends downwardly around, and spaced outwardly from, the master coupling 210 as shown in FIG. 1a. The annulus between the top tube 252 and the master coupling 210 houses a plurality of erosion resistant coupling rings 502 which are stacked end to end. The upper end of the top housing 250 includes a nose ring 254 attached, preferably by welding, to the upper end of the top tube 252. The nose ring 254 has an inside diameter approximating the inside diameter of the coupling rings 502 to thus provide an upper stop for the coupling rings 502. The top housing 250 is tightly threaded to the master coupling 210 to ensure that no gaps exist between the stacked coupling rings 502.
Referring to FIG. 2, the lower end of the master coupling 210 includes a first step portion 217 and a second step portion 218 providing an annulus between the master coupling 210 and the inner pipe joint 102. A shoulder 219 is formed by the lower end of the master coupling 210 where it joins the torque tube 220. At the upper end of the annulus formed by the step portions 217, 218, the torque tube 220 and the inner pipe joint 102, is a loader piston assembly 230 comprising an upper erosion resistant piston ring 504 and a lower piston ring 232. The upper erosion resistant piston ring 504 is bonded, as for example with epoxy, to the lower piston ring 232. The lower piston ring 232 has a stepped outer surface with the upper portion 234 of the lower piston ring 232 having a greater diameter than the lower portion 236 of the lower piston ring 232. The upper portion 234 of the lower piston ring 232 includes a pair of circumferential recesses 238 for receiving a pair of seals 240. The seals 240 are preferably high temperature O-rings to effectively form a seal between the outer surface of the lower piston ring 232 and an inner surface of a loader cylinder 542 positioned in the annulus between the torque tube 220 and the lower piston ring 232. The loader cylinder 542 is made of an erosion resistant material such as tungsten carbide and has a mid portion 544 having an inside diameter approximating the outside diameter of the lower portion 236 of the lower piston ring 232. The mid portion 544 includes a pair of inner circumferential recesses 546 for receiving a pair of seals 248. The seals 248 are preferably high temperature O-rings to effectively form a seal between the outer surface of the lower piston ring 232 and the inner surface of the loader cylinder 542. A chamber 256 is formed between the upper stepped portion 234 of the lower piston ring 232 and the mid portion 544 of the loader cylinder 542. The chamber 256 is sealed both above and below by the pairs of seals 240 and 248 respectively. The chamber 256 is sealed from the external environment by the series of seals 240, 248. As shown in FIG. 2, the upper piston ring 504 overlaps with the lowermost coupling ring 502 and the loader cylinder 542 to provide a continuous erosion resistant protective sheath along the length of the upper portion of the blast joint 100.
Abutting the lower end of the loader piston assembly 230 is a step ring 506 made of an erosion resistant material such as tungsten carbide. The step ring 506 has a stepped outer surface with an upper portion 508 of the step ring 506 having a smaller diameter than a lower portion 510 of the step ring 506. The upper portion 508 of the step ring 506 is positioned between the lower portion of the loader cylinder 542 and the inner pipe joint 102. The erosion resistant step ring 506 and loader cylinder 542 overlap with one another to provide the continuous protective sheath.
As shown in FIG. 1a, a plurality of tubing rings 512 are stacked end to end around the inner pipe joint 102 with the uppermost tubing ring 512 abutting the lower end of the step ring 506. As shown in FIG. 1c, the lowermost tubing ring 512 abuts a short spacer 310 having a lower outer threaded portion 312 which threadably engages an upper inner threaded portion 322 of a drive ring 320. The drive ring 320 includes a lower outer threaded portion 324 which threadably engages an upper inner threaded portion 342 of a die driver 340. An annulus is formed between the die driver 340 and the inner pipe joint 102. As best shown in FIG. 4, abutting the lower end of the drive ring 320 are a plurality of wedges 360. The wedges 360 have a generally straight, flat outer surface 362 and a tapered lower inner surface 364 which meets a straight, flat inner surface 366 that is parallel to the outer surface 362. The wedge 360 is at least partially received in a wedge slot 344 formed in the inner surface of the die driver 340 as shown in FIG. 5. The tapered surface 364 of the wedge 360 engages a complementary tapered outer surface 372 of a die 370. Adjoining the tapered outer surface 372 is a flat outer surface 374 which meets with a downwardly tapered surface 376. An inner surface 378 of the die 370 as shown in FIGS. 6 and 7 has a plurality of intersecting v-grooves 380 cut into the inner surface 378. The inner surface 378 of the die 370 is driven into the outer surface of the inner pipe joint 102 and provides the gripping action required for the transfer of torque to the inner pipe joint 102 as will be explained below in detail.
The flat outer surface 374 of the die 370 has a bore 382 extending into the die 370. As shown in FIG. 7, the bore 382 extends through the die 370, although it is not necessary that the bore 382 extend through the die 370. The bore 382 receives a shearing member (not shown) such as a plastic or brass shear bolt or flat head screw which is inserted through a countersunk hole 386 in the die driver 340 as shown in FIGS. 4 and 5. The shearing member facilitates the assembly of the blast joint 100 as will be explained below.
As shown in FIG. 4, the downwardly tapered surface 376 of the die 370 abuts a tapered surface 392 of a backup ring 390. The backup ring 390 has a threaded outer surface 394 which threadably engages a short inner threaded portion 346 of the die driver 340. The lower end of the backup ring 390 abuts a second step ring 514 made of an erosion resistant material such as tungsten carbide. The step ring 514 has a stepped outer surface with an upper portion 516 of the step ring 514 having a smaller diameter than a lower portion 518 of the step ring 514. Referring to FIGS. 1c and 1d, a plurality of tubing rings 512 are stacked end to end with the uppermost ring 512 abutting the lower end of the step ring 514 and the lowermost ring 512 abutting an erosion resistant bottom ring 520. The bottom ring 520 includes a stepped outer surface with an upper portion 522 of the bottom ring 520 having a greater diameter than a lower portion 524 of the bottom ring 520.
It is to be noted that the erosion resistant piston ring 504, the upper step ring 506, the tubing rings 512, the lower step ring 514, and the bottom ring 520 have the same inside diameter which closely conforms to the outside diameter of the inner pipe joint 102 around which they are stacked. The vertical length of the erosion resistant rings 500 can be varied as desired, with a standard length being between one and a half to two and a half inches.
Referring to FIG. 1d, the lower end of the die driver 340 has an internal threaded portion 348 which engages an external threaded portion 402 of a ring holder 400. The ring holder 400 has an inwardly projecting lip 404 which firmly engages the step portion of the bottom ring 520.
As shown in FIGS. 1c, 1d and 4, the die driver 340 has a uniform lower outer surface which extends upward to a point adjacent the lower step ring 514. The die driver 340 has an inside diameter such that the die driver 340 surrounds the lower stack of tubing rings 512 and the lower step ring 514. The uniform lower outer surface of the die driver 340 steps down to a short outer threaded portion 350 before stepping down even further to a reduced uniform outer surface 352. Threadably attached to the short outer threaded portion 350 is a bottom tube 412 of a bottom housing 410. The bottom tube 412 extends downwardly around, and spaced outwardly from, the reduced uniform outer surface 352 of the die driver 340 and the drive ring 320. The annulus between the bottom tube 412 and the reduced uniform outer surface 352 of the die driver 340 and the drive ring 320 houses a plurality of erosion resistant bottom coupling rings 526 which are stacked end to end. Referring to FIG. 1c, the upper end of the bottom housing 410 includes a bottom nose ring 414 attached, preferably by welding, to the upper end of the bottom tube 412. The bottom nose ring 414 has an inside diameter approximating the inside diameter of the bottom coupling rings 526 to thus provide an upper stop for the stack of bottom coupling rings 526. The bottom housing 410 is tightly threaded to the die driver 340 to ensure that no gaps exist between the bottom coupling rings 526.
As shown in FIG. 1c, the continuous stack of bottom coupling rings 526 overlaps with the lowermost tubing ring 512 and the lower step ring 514 to provide a continuous sheath of erosion resistant rings for the length of the inner pipe joint 102.
In use, the blast joint 100 utilizes the downhole well pressure to hydrostatically apply a downward force on the stack of erosion resistant rings 500 and the lower piston ring 232 positioned between the master coupling 210 and the short spacer 310, thus eliminating any gaps between the erosion resistant rings 500 and the lower piston ring 232 in the stack. The hydrostatic driving force is necessary because of possible shifts of the blast joint protective sheath during handling and operation and also because of the difference in the coefficients of thermal expansion of the materials forming the inner pipe joint 102 and the erosion resistant rings 500.
In use, the downhole well pressure fills the annulus between the inner pipe joint 102 and the torque tube 220 up to the first step portion 217 of the master coupling 210. The pressure in the chamber 256 is sealed off from the well pressure and remains essentially at ambient pressure. As can be seen in FIG. 2, the well pressure results in an upward force acting on the loader cylinder 542 forcing the loader cylinder 542 in the direction of the master coupling 210. The well pressure in the annular area above the loader cylinder 542 results in a downward force on the exposed surface of the upper end of the upper piston ring 504 and the upper exposed end of the lower piston ring 232. The well pressure acting on the loader piston assembly 230 and the loader cylinder 542 decreases the size of the annular chamber 256 by moving the seals 240 and 248 toward each other. The downward movement of the loader piston assembly 230 eliminates any slack between the stack of erosion resistant rings 500. This longitudinal movement of the loader piston assembly 230 relative to the loader cylinder 542 occurs because the well pressure acting on the outside end surfaces of the annular chamber 256 multiplied by the effective area of those surfaces is greater than the ambient pressure inside the chamber 256 multiplied by the area of the upper and lower end of the chamber 256. The pressure inside the chamber 256 can increase slightly because of the reduction in volume of the chamber 256 and because of the increase in temperature, but it will never approach the well pressure which can be several thousand pounds per square inch.
In order the make the blast joint 100 adaptable for use with a snubber unit, a snubbing sleeve 450 having a smooth, continuous exterior surface is used along the mid-section of the blast joint 100 between the master assembly 200 and the bottom housing 410 as shown in FIG. 1b. The snubbing sleeve 450 is connected to the torque tube 220 of the master assembly 200 as shown in FIGS. 1b and 3. The torque tube 220 has lower internal threads 222 engaging external threads 452 of the snubbing sleeve 450. Below the external threads 452 are a pair of circumferential recesses 454 for receiving a pair of seals 456. The seals 456 are preferably high temperature O-rings to effectively form a seal between the outer surface of the snubbing sleeve 450 and the inner surface of the torque tube 220. The snubbing sleeve 450 includes a shoulder 458 below the lowermost circumferential recess 454. The bottom end of the torque tube 220 includes an inner circumferential lock ring groove 262 which receives a lock ring 264. The lock ring 264 will abut the shoulder 458 of the snubbing sleeve 450 and prevent the unthreading of the snubbing sleeve 450 from the torque tube 220. Thus, the lock ring 264 will prevent the snubbing sleeve 450 from being unthreaded during an operation in which it may be necessary to cut off centralizer ribs as described below.
Referring to FIGS. 1a and 1b, a plurality of centralizer ribs 470 may be spaced around the periphery of the snubbing sleeve 450 and the torque tube 220 to maintain the erosion resistant rings 500 away from the wall of the well bore. This will ensure that a washover assembly will be able to pass by the blast joint 100, if necessary, since the rotating milling shoe will not have to attempt to cut through a tungsten carbide ring which is in contact with the wall of the well bore, but instead can cut off the centralizer ribs 470 which are made of a softer material. Additional centralizer ribs 470 are also shown in FIG. 1c attached to the outer periphery of the die driver 340.
As shown in FIG. 1b, an erosion resistant centering ring 513 having an outer diameter slightly greater than the tubing rings 512 is positioned in the stack of tubing rings 512 near the lower end of the snubbing sleeve 450 to maintain the snubbing sleeve 450 and the torque tube 220 centered about the inner pipe joint 102.
Assembly
The assembly of the blast joint 100 will now be described. The assembly procedure will begin at the upper end of the blast joint 100 and proceed to the lower end.
Referring to FIG. 1a, a plurality of tubing rings 512 are installed over the upper end of the inner pipe joint 102. The number of tubing rings 512 should be enough to extend approximately to the projected bottom of the torque tube 220 or snubbing sleeve 450, if desired. The upper step ring 506 is then inserted over the upper end of the inner pipe joint 102. Referring to FIG. 2, the upper piston ring 504 is bonded to the lower piston ring 232 with adhesive, as for example, epoxy, to form the loader piston assembly 230. The pair of seals 240 are inserted in the pair of circumferential recesses 238 in the lower piston ring 232. The pair of seals 248 are inserted in the pair of inner circumferential recesses 546 of the loader cylinder 542. The lower piston ring 232 is then slid into the loader cylinder 542. The loader piston assembly 230 and the loader cylinder 542 are then inserted over the upper end of the inner pipe joint 102. The master assembly 200, including the torque tube 220 and master coupling 210, is then inserted over the upper end of the inner pipe joint 102 and around the tubing rings 512, step ring 506, loader cylinder 542 and loader piston assembly 230. The master coupling 210 is threaded onto the upper pin 104 of the inner pipe joint 102.
As shown in FIG. 1a, five coupling rings 502 are inserted in the top housing 250 such that the uppermost coupling ring 502 abuts the nose ring 254. The top housing 250 is then threaded to the external threaded portion 216 of the master coupling 210. The top tube 252 is fully threaded onto the master coupling 210 so that no gaps exist between the coupling rings 502.
As shown in FIG. 1b and 3, the snubbing sleeve 450 is installed by inserting the seals 456 in the circumferential recesses 454 in the snubbing sleeve 450. The snubbing sleeve 450 is threaded into the lower end of the torque tube 220. The lock ring 264 is then installed in the lock ring groove 262.
Referring to FIGS. 1c, 1d, and 4, the assembly of the lower end of the blast joint 100 is performed by installing the dies 370 in the die driver 340 with the shear members inserted through the countersunk holes 286 in the die driver 340 before being received by the bores 382 in the dies 370. The wedges 360 are then pushed up against the dies 370 as shown in FIG. 4. The drive ring 320 is threaded into the upper end of the die driver 340 until the lower end of the drive ring 320 edges up against the wedges 360. The short spacer 310 (FIG. 1c) is then threaded entirely onto the drive ring 320. The backup ring 390 is installed in the die driver 340 from the lower end of the die driver 340. The backup ring 390 (FIG. 4) is threaded into the die driver 340 until the backup ring 390 contacts the dies 370. The lower step ring 514, three tubing rings 512 and the bottom ring 520 are then inserted into the die driver 340 from the lower end of the die driver 340. The ring holder 400 (FIG. 1d) is firmly threaded into the lower end of the die driver 340 so that the lower step ring 514, the tubing rings 512 and the bottom ring 520 are firmly secured against the backup ring 390.
As shown in FIG. 1c, six bottom coupling rings 526 are inserted in the bottom housing 410. The bottom housing 410 is slid onto the lower end of the inner pipe joint 102 to a point where it is adjacent to the snubbing sleeve 450, if the snubbing sleeve 450 is being used. The die driver assembly is then slid onto the lower end of the inner pipe joint 102 until the bottom ring 520 (FIG. 1d) is approximately 1/4" above the top of the lower threaded pin 106. A backup wrench is put on the outer surface of the die driver 340 and a make up wrench is applied to the outer surface of the drive ring 320. The drive ring 320 is torqued to approximately 1,500 to 2,000 foot-pounds which drives the wedges 360 against the dies 370, shearing the shear members, thus setting the dies 370 into the outer surface of the inner pipe joint 102. The short spacer 310 (FIG. 1a) is rotated to partially unthread the short spacer 310 thus eliminating any gaps between the upper stack of tubing rings 512. The bottom housing 410 is then slid down over the short spacer 310 and the drive ring 320 until it threadably engages the die driver 340. The blast joint 100 is now fully assembled.
The description given herein is intended to illustrate the preferred embodiments of the present invention. It is possible for one skilled in the art to make various changes to the details of the apparatus without departing from the spirit of this invention. Therefore, it is intended that all such variations be included within the scope of the present invention.
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A blast joint resistant to erosion including an inner pipe joint having a substantially smooth outer surface and an upper end and a lower end. A cylindrical lower assembly having an exterior surface suitable for gripping with power tongs is mounted on the lower end of the inner pipe joint with a torque transfer assembly for transferring torque from the lower assembly to the smooth outer surface of the inner pipe joint. A cylindrical upper assembly having an exterior surface suitable for gripping with power tongs is mounted on the upper end of the inner pipe joint. A plurality of erosion resistant rings are concentrically mounted on the inner pipe joint in a vertically continuous arrangement from a point near the lower end to a point near the upper end of the inner pipe joint without a vertical gap between the rings. A hydrostatic piston and cylinder loader provides a vertical load on the plurality of rings to prevent separations between the rings.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation application of U.S. application Ser. No. 11/469,633 filed Sep. 1, 2006, which application is a Divisional application of U.S. application Ser. No. 10/900,843 filed Jul. 28, 2004 (now U.S. Pat. No. 7,118,471 issued Oct. 10, 2006).
TECHNICAL FIELD
This invention relates to knife blades used in the meat processing industry, more particularly to knife blades used in loin knife assemblies of automated loin puller apparatus to separate the loin portion from the belly and fatback portions in pork carcasses.
BACKGROUND OF THE INVENTION
Automatic loin-pulling apparatuses have been developed over the years for removing excess fat and also the belly loin area of an animal carcass, i.e., as a step towards final cutting and packaging of the loin, belly, and fatback. Such automated loin pulling apparatuses include the devices disclosed in U.S. Pat. Nos. 6,089,968 and 6,547,658, for example, which disclose loin knife mechanisms for use with associated meat carcass processing machines. Some such knife apparatuses utilize bent knife blades, including dual blade assemblies.
There is an ongoing high volume of meat carcasses, e.g., pork carcasses, being processed every work day. Thus, an improper knife blade placement measuring only 0.1 inch, for example, can cause drastic loss in yields and price reductions in the belly, loin, and fatback portions, or increase further hand-trimming operations downstream. Thus, the individual loin knives must be carefully shaped, and also able to cleanly cut in a smooth fashion. Further, such blade assemblies must be formed so as to withstand hundreds of thousands of cuttings, e.g., 10,000 cuttings per day or more for multiple months, before needing replacement, so as to prevent costly downtime due to knife blade maintenance and/or change-out.
In the known dual blade loin knife assemblies of the prior art, see for example U.S. Pat. No. 6,547,658, there are two kinds of blades. First, there are so-called “Z-blades”, operable to separate the loin portion from the belly portion of a hog carcass, as well as leave a so-called “belly shelf’ and fingers of lean meat on the belly of a hog, for appearance and for superior bacon yields. Further, there are the so-called “J-blades,” which work from the chine or backbone side of the carcass, used to separate the fatback portion from the loin portion.
However, due to the method of manufacturing such prior art blades, problems exist in the available normal cycles of usage of such blades, requiring relatively frequent machine downtime for blade replacement. Further, some meat processing machines necessitate that the J-blades have a so-called outwardly-extending “tab” portion, wherein an elongated diverter bar member is held by the tab member, as used to direct and position the trailing slab of fatback as it is cut from the pork carcass. As to such prior art “tabbed”-style J-blades, it has been found that those tab portions often break prematurely next to their welds, i.e. before the normal life of the tabbed J-blade has been used up.
Further, the shapes used for the so-called “belly shelf” cutting portions of the prior art Z-blades (as used for cutting a shelf through the longitudinal middle of the finger lean meat of the carcass) did not permit the resultant cut belly shelf to reach the customers' maximum permitted dimensional specification. Thus, unnecessarily large amounts of belly yield had to thereafter be removed off the loin portion, and they became less-desirable trimmings (which are then worth substantially less). Further yet, the prior art style of “J-blades” have, due to their specific shapes, left unusually large portions of excess fatback on the pulled loin portion of the loin middle, and hence also provided poor fatback yields. That, in turn, necessitates extra effort down-the-line in hand trimming operations, resulting in both extra labor costs, as well as a reduced amount of “good” (i.e. connected) fatback, i.e. which is desirable due to the higher price received for sales of the trimmed fatback portion of the carcass when sold as one piece.
More specifically, meat processors using such dual blade loin knife-type machines require that a satisfactorily “belly shelf’ cut be made by the Z-blade, i.e. one that both falls within their dimensional specifications (typically some 2.5 inches±0.2 inches in length) and which also gets sufficient “fingers of lean” meat (found on the back side of the bacon, for good bacon yield), yet which blades also do not cut into or otherwise expose the loin eye meat (which would reduce the value of that select cut of meat). Further, most customers of the cut and pulled pork loins have a specification for their processors that permit no more than one-quarter inch of fat cover on the loin meat. Thus, there is a need to be able to trim the fatback over the loin as close as possible to the loin eye meat, yet again without cutting into and exposing the same.
Further, there has been an inability with the prior art types of J-blades to be adjusted sufficiently vertically, i.e. to be moved substantially down close to the split conveyor belt bed relative to the meat carcass, due to their specific blade configuration. This inability to closely adjust to the bed profile created substantial yield loss for such prior J-blades. This was especially the case when such prior J-blades where used in a meat processing plant which was running so-called “European White” hogs, as those type of pork carcasses have very little fat, and the red meat portions are located substantially close to the skin. Thus, the prior J-blades were not of a shape that could be adjusted effectively relative to the conveyor belts, and thus, they could not run at desirable high yield rates, for processing such “European White” hogs.
Further yet, some processing customers require at the so-called “shoulder end” of the loin portion of the carcass, where some amount of so-called “false lean” meat is present, that the majority of such false lean stay on the loin, yet they also want a small portion of such false lean to stay on the belly, so as to have sufficient meat in the remaining bacon portion.
Additional problems with the known prior art dual blades include that they are formed with relatively rough surfaces that create a substantial amount of cutting drag through the carcass. This in turn places substantial side loads on the loin puller machine's blade-related components, such as the bushings, linkage parts, blade-holding components, and bearings. Thus, such blade-related components often require early replacement, necessitating machine downtime. Also, if such worn components are not properly replaced, then due to the end-play that they create, there are yet additional yield losses, broken carcass bones, and improper meat cutting, resulting then in yet additional lost revenue.
Thus, there has been a need for improved “Z-blades” and “J-blades” for use in meat production operations, especially for use in pulling loins in pork carcass processing plants.
BRIEF SUMMARY OF THE INVENTION
There is disclosed as one aspect of the present disclosure a Z-blade member having a cut belly shelf formed of an extended length, to consistently reach the maximum end of the customer-set dimensional specification for that shelf. That shelf blade portion is formed of two distinct sections, the first being a generally straight section adapted to cut and divide the finger lean meat as close as possible to the spare rib around the pork middle, and a second further generally straight section, but formed at a shallow angle canted down from the first shelf portion and adapted to operate as sufficiently low as needed to avoid cutting into any of the red meat portion of the loin eye, whether as a small “pencil score” or as a large “body score”, in view of the significant extended length of that shelf portion of the Z-blade.
Another aspect of the present invention, as an alternate form, provides a Z-blade also having a shelf portion of extended length, again to regularly reach the customer's maximum belly shelf dimension specification, but formed of a gradual sweeping curve shape, rather than two straight sections divided by an intervening shallow angle. Again, the first part of the curve of the shelf is adapted to cut out the finger lean meat close to the spare rib as possible, while the second portion of the curve of the shelf is adapted to cut close to, yet stay sufficiently distant from so as not to score, the loin eye meat.
Additionally, as another aspect of the disclosure, there is a J-blade member formed so as to have an initial meat cutting blade portion that is substantially straight and formed at a tight upright angle, so as to closely trim the “saddle area” of the fatback from adjacent the loin without over-exposing the false lean from the shoulder end or “over-scoring” the ham end (but still creating a desired “silver dollar”-size ham end score). Further, there is a lower sweeping curve portion, formed of a tight radius adapted to closely match the shape of the conveyor bed, so as to allow the blade to be adjusted closely adjacent the same, thereby resulting in increased yield.
Another aspect of the disclosure is a modified form of the J-blade, for use with machines that require a diverter bar tab member to be present, where the tab is so formed as to minimize its premature breakage before the blade is otherwise normally used up.
Further aspects of the disclosure include a method of forming Z-blades and J-blades for a pork loin puller apparatus resulting in a substantially extended useful life for such blades, a substantial elimination of the welded tab breakage problem of the prior art, and with polishing of the blade surface, resulting in a substantial reduction in side loads on the blade-holders and other blade-related components.
Yet a further aspect of the disclosure is a method for forming both Z-blades and J-blades for meat carcass processing operations, where the resulting blades provide increased yields of loin, belly, and fatback, resulting in increased revenues, minimize hand-trimming operations, and have a substantially increased overall useful life compared to prior art dual loin knife blades.
BRIEF DESCRIPTION OF THE DRAWINGS
The means by which the foregoing other aspects of the present invention are accomplished, and the manner of their accomplishment will be readily understood from the following specification upon reference to the accompanying drawings, in which:
FIG. 1 is a front elevation view of a Z-blade of the present disclosure;
FIG. 2 is a side elevation view of the Z-blade of FIG. 1 ;
FIG. 3 is a cross-sectional view, taken along lines 3 — 3 / 4 — 4 of FIG. 1 , reflecting a single bevel cutting edge, and shown as a right-hand blade;
FIG. 4 is a cross-sectional view, taken along lines 3 — 3 / 4 — 4 of FIG. 1 , reflecting a single bevel cutting edge, and shown as a left-hand blade;
FIG. 5 is similar to FIGS. 3 and 4 , but depicts a double bevel cutting edge for a Z-blade;
FIG. 6 is a front elevation view of a J-blade of the present disclosure;
FIG. 7 is a side elevation view of the J-blade of FIG. 6 (configured as a left-hand blade;
FIG. 8 is a cross-sectional view, taken along lines 8 — 8 / 9 — 9 of FIG. 7 , reflecting a single bevel cutting edge, and shown as a left-hand blade;
FIG. 9 is a cross-sectional view, taken along lines 8 — 8 / 9 — 9 of FIG. 7 , reflecting a single bevel cutting edge, but shown as a right-hand blade;
FIG. 10 is similar to FIGS. 8 and 9 , but depicts a double bevel cutting edge for a J-blade;
FIG. 11 is a front elevation view of an alternate form of the J-blade, namely a tabbed-style J-blade;
FIG. 12 is a side elevation view of the tabbed-style J-blade of FIG. 11 ;
FIG. 13 is a cross-sectional view, taken along lines 13 — 13 / 14 — 14 of FIG. 11 , reflecting a single bevel cutting edge, and shown as a right-hand blade;
FIG. 14 is a cross-sectional view, taken along lines 13 — 13 / 14 — 14 of FIG. 11 , reflecting a single bevel cutting edge, and shown as a left-hand blade;
FIG. 15 is similar to FIGS. 13 and 14 , but depicts a double bevel cutting edge for the tabbed-style J-blade;
FIG. 16 is an enlarged view of the Z-blade of FIG. 1 , shown as a left-handed blade in its operational environment above an associated conveyor bed, and a loin meat carcass (shown at its shoulder end);
FIG. 17 is an enlarged view of the J-blade of FIG. 6 , shown as a left-handed blade in its operational environment above an associated conveyor bed, and a loin meat carcass (shown at its shoulder end); and
FIG. 18 is an enlarged view of the alternate tabbed-type J-blade of FIG. 11 , shown as a left-handed blade in its operational environment with an associated conveyor bed and a loin meat carcass (shown at its shoulder end).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present disclosure relates to dual loin knife blades that provide improved processing operating efficiencies and yields over the prior forms of Z-blades and J-blades as disclosed in U.S. Pat. No. 6,547,658, and further overcomes many of the deficiencies found in the blades, and their shapes and manufacturing methods.
Having reference to the drawings, wherein like reference numerals indicate corresponding elements, there is shown in FIG. 1 an illustration of a Z-blade member, generally denoted by reference 20 . Z-blade 20 includes (from top to bottom in that Figure): an upper mounting portion, generally denoted by region reference 22 ; an upper central blade portion 24 ; an angle bend forming a rib bone radius portion 26 ; a shelf portion 28 comprising an upper initial or finger shelf portion 30 , a relatively short shallow-angled shelf bend portion 32 , and a lower or loin eye avoidance shelf portion 34 (hereafter the “LAS portion”); an angle bend forming a belly cutoff radius 36 ; a belly cutoff blade portion 38 ; and a lower mount portion 40 . Portions 28 , 30 , 32 , 34 , 36 and 38 , collectively, form a lower central blade portion.
More specifically, the upper mounting portion 22 of Z-blade 20 comprises an S curve portion 42 and an upper mount portion 44 which mounts to a loin puller apparatus' upper blade mount (not shown). It will be understood that, depending on the specific mounting block arrangement and location (not shown) present in a given loin pulling machine (not shown), there may be a need for an even larger (or smaller) S curve portion, or instead, no need at all for the linkage-adjusting S curve portion 42 of Z-blade 20 . Instead, portion 42 and upper mount portion 44 can simply be formed as an elongated straight mounting section of Z-blade 20 , or even take some other configuration, again depending on the specific upper mounting requirements for the Z-blade in a given application.
As seen in FIGS. 1 and 2 , the cutting edge 46 runs from an upper end point 48 to a lower end point 50 . Those end points 48 , 50 may be readily extended upwardly and downwardly as needed for a given loin puller machine, depending on the type and size (i.e. live weights) of hog carcass being processed. Further, cutting edge 46 can be formed with either an inner or outer single beveled cutting edge, such as shown in FIGS. 3 and 4 , or instead, can be formed as a double bevel cutting edge, as shown in FIG. 5 , depending on the preference of the customer. In FIG. 2 , cutting edge 46 is shown as an inner single bevel cutting edge (but again, that type edge is depicted merely for purposes of presentation).
Upper central blade portion 24 is shown as a generally elongated straight section ending at its lower end in the rib bone radius 26 . It will be understood that upper straight blade portion 24 is positioned substantially above the entry point of the meat carcass into the blade (such point being shown as line M—M in FIG. 2 ). Nevertheless, blade portion 24 still carries a cutting edge 46 , primarily so that if any carcasses are improperly aligned within the loin pulling machine (not shown), the cutting edge 46 will be present to cut through the bones and meat, so that such mis-aligned carcass section does not jam up the machine and cause unwanted downtime.
The angle of the rib bone radius 26 is quite tight, and thus, relative to now the lower central blade portion, sets up an aggressive positioning of the shelf portion 28 towards the loin area, as compared to that angle in the known prior art blades, which instead typically had much larger radii, such as 114°. That is, the angle of the present rib bone radius 26 is preferably in the range from approximately 107° to 111°, and more preferably is approximately 109°.
The permitted length of a cut belly shelf on a loin is typically specified by the end user customers to be 2.5 inches plus or minus 0.2 inch. The prior art Z-blades, however, purposely had only a 2.5 inch maximum shelf length. However, with the present invention, the shelf length (designated as length S.L. in FIG. 2 ) for the elongated shelf portion 28 is 2.7 inches, and therefore is able to cut deeper into the belly area and near the loin eye meat. That resultant elongated length of cut belly shelf thereby increases the overall weight of the loin portion, with resultant increased revenues for the processors. However, if such an extended shelf length S.L. of 2.7 inches were undertaken with a straight shelf blade design, such as present in the known prior art Z-blades, that extended straight blade length would improperly cut right into the loin eye meat.
Advantageously, the present shelf 28 has been formed of two sections, namely an upper, initial finger shelf portion 30 , which is formed preferably as a straight section extending approximately 0.680 inch in length, and within a preferred range from approximately 0.650 to 0.710 inch in length, and then the second shelf or LAS section 34 , i.e. the loin avoidance shelf portion, which is also formed preferably as a straight section having a length of approximately 0.561 inch, and within a preferred range from approximately 0.531 to 0.591 inch in length. Formed between those two shelf portions 30 and 34 is a bend angle portion 32 having a shallow bend angle α in the range of approximately 9° to 13°, and preferably approximately 11.2°. The radius to create angle α is approximately 4.8845 to 4.9445 inches, and preferably 4.9145 inches. Angle α allows the LAS blade portion 34 to cant down slightly from the upper finger shelf portion 30 . It will be understood that if angle α is made too great, than the belly yield can be lost, i.e., the depth of the edge of the belly is no larger as much as the customer-required depth specification of one-half inch minimum, thereby necessitating additional trimming labor to cut back the belly shelf towards the spare rib, until the required one-half inch depth dimension is again attained. On the other hand, if angle α is made too small, then there is a risk of exposing and cutting into the loin eye meat by the LAS section 34 . Thus, by using a bend angle α within the above range, for the extended shelf S.L., that angle α allows the LAS portion 34 completely to avoid interference with the red meat of the loin eye. Thus, the two-part extended length shelf 28 , with intervening angle α of bend portion 32 , is a substantial improvement over the straight shelves of the prior art Z-blades, because an extended shelf length of meat can now be cut, including cutting closer to the spare rib and through the finger lean, yet without cutting into the loin eye meat. This extended length shelf results in substantial yield gains of the loin portions for the meat processor.
As seen in FIG. 2 , the cutoff radius 36 has a tight angle bend created by a radius in the range from approximately 0.220 to 0.280 inches, and more preferably of approximately 0.2500 inch. The angle between the lower shelf portion 34 , relative to the belly cutoff blade portion 38 , is formed within the range of approximately 117.2° and 121.8°, and preferably approximately 119.5°. The belly cutoff blade portion 38 is thus formed as a substantially vertical portion including the cutting edge 46 and lower end point 50 , and is operable to cutoff the fatback from the belly of the pork carcass. The lower mounting portion 40 mounts within the lower mounting block (not shown) of the associated loin pulling machine (not shown); again, it can take any of several forms as needed to be held properly by such mounting blocks. Thus, the shape shown for lower mounting portion 40 in FIGS. 1 and 2 is merely for purposes of illustration.
The overall length (designated as length O.L. in FIG. 2 ), for the Z-blade of the present disclosure is normally in the range from approximately 13⅞ inches to 14⅛ inches, and is preferably some 14 inches long, as measured in its finally formed shape. The range of thickness for the Z-blade 20 is in the preferred range from approximately 0.130 inches to 0.150 inches, and is preferably 0.140 inches. As noted, the upper central blade portion 24 and belly cutoff blade portion 38 are generally parallel to one another. As an alternate form of two section shelf 28 , it could be formed as one continuous downwardly curved section, formed of a radius of preferably 7.287 inches, and within the preferred range from 7.257 inches to 7.317 inches. Such a curved shelf blade portion of the extended 2.7 inch length is a substantial improvement over prior art shelf blade portions.
Turning to FIGS. 6 and 7 , there is shown as one aspect of the present disclosure, an improved J-blade, generally denoted by reference numeral 60 , and for use with certain types of loin puller machines. That is, certain loin puller apparatus (not shown) were modified into dual blade machines in the field, i.e. converted from a single hoop-style blade machine to a dual blade loin knife-type machine. Due to such field modifications, including the style and location of the specific blade mounting blocks used, and the other components found in those type loin puller machines, the J-blades used with those field-modified machines are necessarily formed of a specific shape. Thus, the improved J-blade 60 for use with such field-modified machines includes a dual bevel cutting edge 62 (used for presentation purposes only in this disclosure, and again is dependent on the end user's preference), having respective upper and lower end points 64 , 66 . J-blade 60 includes (from top to bottom in those Figures): an upper mount portion 68 ; an upper central blade portion 70 ; a rib bone radius 72 ; a lower central blade portion having generally straight fatback trimming portion 74 , a transition area 76 , and a sweeping radius portion 78 ; a cutoff angle bend 80 ; a generally straight cutoff portion 82 ; and a lower blade mount portion 84 .
More specifically, the upper central blade portion 70 comprises an S-curve portion 86 which helps properly position the upper mount portion 68 in its needed linkage position. That is, the S-curve portion 86 helps as a linkage step to properly locate (from left to right in FIG. 7 ) the upper mount portion 68 relative to the upper mounting block (not shown) of an associated field-modified loin puller machine (not shown). Thus, again here, similar to the above-described Z-blade, the blade portions 68 and 70 can take other shapes rather than the S-curve portion 86 , as needed to accommodate the proper linkage positioning with the upper blade mounting blocks.
The feather bone radius 72 is preferably in the preferred range from 0.220 to 0.280 inches, and more preferably is approximately 0.2500 inch. That relatively tight radius allows the straight fatback trim portion 74 of the disclosed improved J-blade 60 to be aggressively positioned (i.e. in a fairly vertical alignment and quite close to, i.e. tighter into against, the feather bones (not shown) of the pork carcass), than was ever previously available with the prior art J-blades. Preferably, the relative length of the straight fatback trim portion 74 is approximately 2.079 inches long and within the preferred range of approximately 2.049 to 2.109. Further, it will be understood that the prior art blades were formed of a flat curve along that fatback trim portion of the overall J-blade, rather than substantially straight as formed with the fatback trim portion 74 of the disclosed J-blade 60 . By having such a straight blade portion for fatback trim portion 74 , the result is that less overall fat remains on the loin portion that is pulled, and instead, more fat is cut into the fatback portion that is trimmed away. This results in better yields, and hence, in better revenues for those respective sections of the carcass when sold.
There is a small transition area 76 located between the generally straight fatback trim portion 74 and the sweeping radius portion 78 of J-blade 60 . The radius for the sweeping radius portion 78 is much more aggressive, i.e. is much tighter, than that present in the prior art J-blades. That is, the radius in area 78 is preferably in the range from approximately 3.939 inches to 3.999 inches, and more preferably is approximately 3.9691 inch. The sweeping radius portion 78 of J-blade 60 operates to remove the fatback over the loin eye, and thus, that tight radius blade portion causes a smaller thickness of fat cover (not shown) to remain over the loin eye, yet that portion 78 does not enter the red meat of the loin eye. For example, the most aggressive radius present in the known prior art fatback blade portions was relatively flat, i.e. only approximately 4.117 inches, such that that relatively flat radius inherently created a substantial yield loss in the fatback trim portion of the carcass. The tight sweeping radius of present blade portion 78 then transitions into, and comes down low towards belt bed, due to the sharp cutoff angle bend 80 . That sharp bend 80 has a preferred radius of only approximately 1.875 inch, and is within a preferred range of only approximately 0.1575 inch to 0.2175 inch. The angle between the sweeping radius portion 78 relative to the cutoff portion 82 , is formed within the range of approximately 83.9° and 88.5°, and preferably 86.2.
Stated another way, the fatback trim portion 74 comprises approximately the first two fifths of the meat cutting portion of the J-blade 60 , and the lower sweeping radius portion 78 comprises approximately the lower remaining three fifths. This aggressive shape, thus, trims the fatback over the loin eye very close in with a tight radius, and puts the blade quite close to the red meat portion of the loin, resulting in a larger piece of fatback that is now worth more, since it contains more connected weight. Further, the resulting loin is thus formed to be of a very first quality, since it has only the minimal dimensional specification of remaining fat cover. If the overall meat cutting portions of the blade (i.e. portions 74 and 78 ) were formed too tight, i.e. too close in against the loin eye, then they would expose the loin red meat, which then drops the quality and price of the loin. On the other hand, if those blade portions 74 , 78 were formed to be too loose or wide, then there is less fatback trimmed off, such that too much fat is left on the loin. That, in turn requires extra and costly subsequent “hand knife” labor for trimming away that extra fatback. In effect, the tight radius of cutoff angle bend 80 allows the sweeping radius portion 78 to start right away at its lower end, such that the sweeping radius portion 78 gets up close into the loin eye area, and thereby, in effect, allows the greatest recovery of the fatback.
It will be noted that FIGS. 8 , 9 and 10 , disclose, respectively, inner and outer single bevel cutting edges 63 , and a dual bevel cutting edge 62 .
Shown in FIGS. 11 and 12 , as an alternate aspect of the present disclosure, is a modified form of a J-blade for use with those certain different types of loin puller processing machines that need a tab for holding a diverter bar, and which machines are otherwise different from the machines which utilize the style of J-blade 60 of FIGS. 6 and 7 .
Thus, there is shown in FIGS. 11 and 12 , an improved tabbed-style J-blade, as generally denoted by reference numeral 90 . Tabbed J-blade 90 includes a dual bevel cutting edge 92 with respective upper and lower end points 94 , 96 . The tabbed J-blade 90 includes (from top to bottom in FIG. 12 ): an upper mount portion 98 ; an upper central blade portion 100 , which extends generally down to that point along tabbed blade 90 as designated by carcass entry line M—M, i.e. the line at approximately which the top of the pork carcass enters the blade; an elongated sweeping curve portion, generally designated by reference numeral 102 , which includes two separate blade portions, namely a tight upper radius or fatback trim portion 104 , as separated by a transition area 106 , and a tight lower radius or sweep radius portion 108 (which carries the integrally-formed tab member 109 , as having an inner opening 111 to hold and retain the associated diverter bar (not shown)); a cutoff angle bend 110 ; a generally vertical cutoff blade portion 112 ; and finally, a lower mount portion 114 .
More specifically, the upper central portion 100 includes a generally shallow S-curve portion 116 which, along with the upper mount portion 98 , can be larger or smaller (as needed) and provides the proper positioning and linkage setup for mounting the upper end of the J-blade 90 to the mounting blocks (not shown) of the loin puller machines (not shown). Again, as with the similar portion of the above-described Z-blade 20 and J-blade 60 , the upper portions 98 and 100 of tabbed J-blade 90 can be formed in different configurations, as needed, to accommodate the upper mounting block for a given loin puller machine (not shown). However, starting from essentially carcass entry line M—M on down, the shapes of the various blade portions for tabbed J-blade 90 are specially formed. The upper fatback trim portion 104 is preferably formed of a radius in the range of approximately 3.970 inches to 4.030 inches, and more preferably is of approximately 4.0 inches. This tight curvature for upper fatback trim portion 104 permits the blade 90 at that location to properly divide and trim the finger lean portions and to cut near the feather bone area of the loin, but without cutting into the loin eye meat. Then, after the transition area 106 , the separate and different radius of the lower sweep radius portion 108 is within the range from approximately 3.470 inches to 3.530 inches, and more preferably, is of approximately 3.5 inches. As seen, those two respective and distinct radiuses blend into one another along the transition area 106 . The cutoff angle bend 110 is preferably formed of a tight radius of approximately 0.360 inch, and within a preferred range of from 0.330 inch to 0.390 inch.
While it is of a slightly different overall shape from the corresponding portions of non-tabbed J-blade 60 (of FIGS. 6 and 7 ), the lower meat cutting portions 104 and 108 of the tabbed J-blade 90 are still substantially more aggressive, i.e. tighter in towards the feather bones and loin eye meat, than any of the known prior art tabbed-style J-blade designs. In effect, the curved cutting portions 104 and 108 permit substantially more fatback to be trimmed from the loin meat areas, and thus, add back an otherwise lost portion of the fatback segment, thereby substantially increasing yields, over the prior art tabbed-style J-blade.
As shown in FIG. 16 , the Z-blade 20 of the present disclosure is depicted in its normal operating environment, namely in operation above a split conveyor belt-type bed 116 , as shown carrying the shoulder end of the pork loin, generally depicted by reference numeral 118 . As seen, the shelf portion 28 properly cuts the finger lean meat 120 yet does not get too close to the loin meat 112 . However, as will be understood, the Z-blade 20 is formed so as to leave a proper “silver dollar”-sized score (not shown) on the belly.
Turning to FIG. 17 , there is shown, in the operating environment similar to FIG. 16 , the non-tabbed J-blade 60 of the present disclosure, including the split conveyor belt bed 116 and the carcass shoulder end 118 . As seen, the sweeping radius portion 78 of non-tabbed J-blade 60 mirrors, i.e. is shaped to closely follow, the overall profile of the belt bed 116 . Thus, when needed the blade, in effect, is allowed to lay down directly onto the belt bed, as it were, so as to be able to closely trim the loin shoulder end 118 . This blade profile-mirrors-bed profile feature is particularly advantageous when pulling loins of so-called “European White” hog carcasses, yet can be accomplished without at all cutting into the belt bed 116 . In effect, when blade 60 is so lowered, there is no “air gap” left between the profile of the lower sweeping radius portion 78 and the belt bed 116 . This blade profile-mirrors-bed profile feature is further accentuated by the fact that the radius formed in cutoff angle bend 80 of non-tabbed J-blade 60 is substantially sharp. Thus, a substantially greater amount of fatback 124 can be cut away by the aggressive shape of the meat cutting portions of non-tabbed J-blade 60 . Further, the specific configuration of J-blade 60 will not over-expose false lean at the shoulder end or over-score the ham end of the loin.
Turning to FIG. 18 , there is shown the tabbed J-blade 90 of the present disclosure as depicted in its operating environment (similar to FIGS. 16 and 17 ), and again depicting the split conveyor belt bed 116 and the loin shoulder end 118 . As noted, the angle of the cutoff angle bend 110 is not quite as sharp, i.e. not as tight (as the corresponding angle of cutoff angle bend 80 of non-tabbed J-blade 60 ). Nevertheless, the lower sweep radius portion 108 of tabbed J-blade 90 is still able to come down substantially close to, and have a generally similar profile to, the conveyor belt bed 116 . Thus, here again, and contrary to the prior art tabbed J-blade designs, a substantial greater portion of the fatback 124 of the carcass is able to be cut away from the loin 122 , all so as to in increase both loin and fatback yields when using the tabbed J-blade 90 of the present disclosure. Further yet, the tabbed-style J-blade must not expose too much false lean, or “over score” the loin's ham end, i.e., beyond the desired “silver dollar”-size score.
Now, turning to the method of forming the various Z-blades and J-blades of the present disclosure, it will be understood that the blades are preferably formed of D-2 steel material, die-stamped rather than hand-formed (as in the prior art) for greater accuracy and consistency, and are heat treated for greatest longevity. The preferred method for forming the respective blades of the present disclosure, thus, includes the following steps:
(a) preliminarily, when forming a tabbed-style J-blade, form a laser cut, or mill cut as desired, of the profile of the blade and attached tab, all as an integral unit formed from one piece of metal stock (such that the tab member is not a weaker piece due to being welded later on to a separate blade member, as was done in the prior art);
(b) mill the outer blade profile (either style of blade), on a milling machine;
(c) machine the milled blades' overall cutting edge, whether as a double or single bevel edge, and whether as an inner or outer single bevel edge;
(d) anneal the machined blades, so as to soften them, by subjecting them in a preferred temperature range of from approximately 1060° F. to 1080° F., in the preferred time range from approximately 85–95 minutes;
(e) die-stamp the annealed blades, so as to form the actual accurate curves, angle bends, and overall blade profile to the respective Z- and J-blades;
(f) heat treat the die-stamped blades, to within the range on the Rockwell scale of between approximately R.C. 44–54;
(g) quality control check the blade profile of the heat-treated blades, to make sure the cutting edge profile has not changed during the earlier heat treatment step; and
(h) polish all surfaces of the blades to generally a substantially flawless mirror-like finish, namely to a polished surface finish within the preferred range from approximately 4 to 32 microinches.
Thereafter, the finished and polished blades are wrapped and shipped to the customer, whereupon the customer grinds on their own final cutting edge, to their own specific edge grinding specifications and desires. They can also then subsequently re-sharpen the blade over its lifetime of use.
Due to the foregoing method of forming the present Z- and J-blades, a substantially superior blade member is obtained. For example, contrary to the rough surface finish established on the known prior art blades, the mirror-like polished surface finish found on the blades of the present disclosure helps to substantially reduce side load forces created by the blades as they cut through the meat carcasses. This is because the polished surface finish creates less drag on the blade-related machine components. This in turn substantially reduces blade wear, and blade-related component wear for the loin puller machines, thereby resulting in increased savings in maintenance downtime and replacement parts.
Further, the present tabbed-style J-blades are formed by laser cutting (or mill-cutting, as desired) both the blade and the tab as a single unit, i.e. all formed as an integral piece from one piece of metal stock. This is contrary to the prior art method of welding and braising on the tab as a separate item to the blade. Thus, due to that difference, the present one-piece tabbed-style J-blades has a substantially longer useful life, as there is no problem in having a welded tab portion prematurely break off from the remaining blade portion. Further, by heat treating the blades to be within the R.C. 44–54 range, the present blades are substantially stronger and result in a longer useful life. Yet further, as a result of die-stamping the curves and bends of the present Z- and J-blades, instead of hand forming then as done with the prior art blade, a very accurate, and consistently-formed, blade portion is achieved.
By permitting with the presently-disclosed blades an additional two tenths of an inch of fatback layer to remain on the belly (which around the time of filing the subject application was running approximately $1.23 per pound, as contrasted to the then current price for fat hand trimmings off the loin of only $0.46 per pound), the extra two tenths of an inch, across the entire length of the pork belly, times typically some 1200 carcass pieces per hour, times two loins per animal, times the typical 16-hour per day shifts of such pork carcass processing operations, results in additional revenue to the processor of literally tens of thousands of dollars per day. Similarly, substantial revenue savings, in effect, occurs by reducing the amount of needed later “hand trimming” of excess fatback over the loin eye meat.
From the foregoing, it is believed that those skilled in the art will readily appreciate the unique features and advantages of the present disclosure over the previous types of dual loin knife blades for meat processing operations. Further, the foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitation should be understood therefrom, as modifications will be obvious to those skilled in the art.
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Dual loin knife blade members, in the form of a Z-blade and two styles (tabbed and non-tabbed) of J-blades, for use with knife assemblies in loin pulling machines for pork processing operations. The Z-blade knife comprises a shelf portion of extended length, formed of two separately-shaped blade portions, to maximize to the allowable customer dimensional length specification for the meat shelf being cut, while not cutting into and exposing the red meat of the pork loin eye. The J-blade, of either the tabbed or non-tabbed style, includes lower sweeping radius blade portions allowing the J-blade to lie closely adjacent and generally conform to the profile of the underlying split conveyor belt bed shape. The profiles for the present Z-blades and J-blades permit substantially increased yield in pork loin processing operations, reduced subsequent hand-trimming labor, as well as extended blade wear. A method is also disclosed for manufacturing the Z-blades and J-blades, resulting in increased wear, less surface drag on blade-related components and minimizing premature tab breakage on the tabbed-style J-blades.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. Nos. 14/046,081 and 14/046,120, filed 4 Oct. 2013, a continuation-in-part of application Ser. No. 14/219,836, filed 19 Mar. 2014, a continuation-in-part of application Ser. No. 14/269,895, filed 5 May 2014, each of which is herein incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates in general to an electrode having metal nanoparticles synthesized by a novel route, and to an electrochemical cell bearing such an electrode.
BACKGROUND
[0003] Metal-air battery has gained more and more attention as one of the post lithium-ion battery technologies. This is ideally supported by the concept that O 2 gas as an active material is continuously coming from outside of the battery.
[0004] Currently, Li-air battery is a promising candidate of high energy density type rechargeable batteries, because the most negative potential of Li metal brings about the highest working potential. The Li anode still has the serious problems of dendrite growth and high moisture reactivity. However, because of such a high working voltage, this battery technology is of significant interest in post lithium-ion batteries.
[0005] On the other hand, this system has many issues on the cathode side as well. The cathode in Li-air batteries requires an oxygen reduction reaction associated with the Li ion during discharging, and the subsequent decomposition reaction of Li compounds (such as Li 2 O 2 , LiOH and Li 2 CO 3 as discharge products) during recharging. In particular, carbon as a conducting support has been recently reported to be corroded during recharging, resulting in generation of unwanted CO 2 gas, and the accumulation of insulative/resistive carbonates. In terms of battery performance, these accumulation processes cause poor rechargeability, rate capability and cycleability of lithium-air batteries.
[0006] One of the countermeasures to avoid carbon corrosion is to replace carbon with non-carbon materials such as ceramics and metal. Bruce et al. demonstrated a version of this strategy with nanoporous gold and TiC ceramic as alternatives carbon cathode. By applying this idea to non-aqueous Li-air batteries, carbon corrosion was remarkably suppressed, and battery performance was drastically improved. Therefore, non-carbon materials are of great interest in this research field.
[0007] One of the issues for carbon cathode alternatives is the low surface area of non-carbon materials. Carbon is often used as porous materials with high surface area because it works well at practically high rates. Considering cost, mass production and quality, developing non-carbon materials with high surface area is a big challenge. Therefore, non-carbon materials with high surface area are strongly desired.
SUMMARY
[0008] Electrodes and electrochemical cell employing metal nanoparticles synthesized by a novel route are provided.
[0009] In one aspect, an electrode for a metal-air battery comprising metal nanoparticles is disclosed, wherein the metal nanoparticles are synthesized by a method comprising adding surfactant to a reagent complex according to Formula I:
[0000] M 0 .Xy I,
[0000] wherein M 0 is zero-valent metal, X is a hydride, and y is an integral or fractional value greater than zero.
[0010] In another aspect, a metal-air battery is disclosed. The metal-air battery has an electrode, the electrode comprising metal nanoparticles, the metal nanoparticles having been synthesized by a method comprising adding surfactant to a reagent complex according to Formula I:
[0000] M 0 .Xy I,
[0000] wherein M 0 is zero-valent metal, X is a hydride, and y is an integral or fractional value greater than zero.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Various aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments taken in conjunction with the accompanying drawings, of which:
[0012] FIG. 1 is an x-ray photoelectron spectrum of an Ag.(LiBH 4 ) 2 complex prepared by the process reported here;
[0013] FIG. 2 is an x-ray diffraction spectrum of silver nanoparticles synthesized by a disclosed process using the Ag.(LiBH 4 ) 2 complex of FIG. 1 ;
[0014] FIG. 3 is a plot of voltage vs. logarithm of current density for three lithium-air batteries having cathodes with different forms of silver;
[0015] FIG. 4 is a plot of voltage vs. capacity for four lithium-air batteries; and
[0016] FIG. 5 is a plot of voltage vs. logarigthm of current density for two lithium-air batteries, where carbon powder is incorporated in the cathodes.
DETAILED DESCRIPTION
[0017] The present disclosure describes electrodes for use in metal-air batteries, as well as the metal-air batteries which include an electrode of the type disclosed. The electrodes include metal nanoparticles synthesized by a novel mechanochemical synthetic technique. The metal nanoparticles which are included in the electrode can be of any metal. In addition, the metal nanoparticles included in the disclosed electrodes are easily producible at industrial scale, at uniform size down to low nanometer, and are highly pure, for example being devoid of oxides.
[0018] As shown below, the metal-air batteries and electrodes of the present disclosure demonstrate superior performance as compared to similar system which, instead of metal nanoparticles synthesized by the disclosed novel method, employ macroscale metal, microscale metal, or commercially available nanoparticulate metal.
[0019] An electrode for use in a metal-air battery is disclosed. The electrode includes zero-valent metal nanoparticles, where the term “zero-valent” means that the metal nanoparticles consist essentially of metal which is in oxidation state zero, or elemental metal. The zero-valent metal nanoparticles included in the electrode, referred to henceforth simply as “metal nanoparticles” can be prepared by a disclosed method for synthesizing metal nanoparticles which includes a step of contacting a reagent complex with a surfactant. The reagent complex used in the method for synthesizing metal nanoparticles has a formula according to Formula I:
[0000] M 0 .X y I,
[0000] wherein M 0 is a zero-valent metal and X is a hydride. The subscript y can be any positive fractional or integral value. In some cases, y can be a value from 1 to 4, inclusive. In some cases, y can be a value from 1 to 2, inclusive. In some cases, y will be approximately 2.
[0020] The zero-valent metal can be any transition metal, post-transition metal, alkali metal, or alkaline earth metal. In some instances, the zero-valent metal can be a noble metal. In one non-limiting example discussed below, the zero-valent metal is silver
[0021] The hydride employed in Formula I can be a solid metal hydride (e.g. NaH, or MH 2 ), metalloid hydride (e.g. BH 3 ), complex metal hydride (e.g. LiAlH 4 ), or salt metalloid hydride also referred to as a salt hydride (e.g. LiBH 4 ). In some examples the hydride will be LiBH 4 , yielding a reagent complex having the formula M.LiBH 4 . In some specific examples, the reagent complex will have the formula M.(LiBH 4 ) 2 . It is to be appreciated that the term hydride as used herein can also encompass a corresponding deuteride or tritide.
[0022] The reagent complex can be a complex of individual molecular entities, such as a single metal atom in oxidation state zero in complex with one or more hydride molecules. Alternatively the complex described by Formula I can exist as a molecular cluster, such as a cluster of metal atoms in oxidation state zero interspersed with hydride molecules, or a cluster of metal atoms in oxidation state zero, the cluster surface-coated with hydride molecules or the salt hydride interspersed throughout the cluster.
[0023] One process by which a reagent complex according to Formula I can be obtained includes a step of ball-milling a mixture which includes both a hydride and a preparation composed of metal. The preparation composed of metal can be any source of metallic metal, but will typically be a source of metallic metal which contains zero-valent metal at greater than 50% purity and at a high surface-area-to-mass ratio. For example, a suitable preparation composed of metal would be a metal powder comparable to commercial grade metal powder.
[0024] The ball-milling step can be performed with any type of ball mill, such as a planetary ball mill, and with any type of ball-milling media, such as stainless steel beads. It will typically be preferable to perform the ball-milling step in an inert environment, such as in a glove box under vacuum or under argon.
[0025] An x-ray photoelectron spectrum of an example reagent complex, Ag.(LiBH 4 ) 2 , obtained by this process is shown in FIG. 1 . An x-ray diffraction spectrum of the silver nanoparticles synthesized by addition of surfactant to this reagent is shown in FIG. 2 .
[0026] In some variations of the method for synthesizing metal nanoparticles, the surfactant can be in suspended or solvated contact with a solvent or solvent system. In different variations wherein the reagent complex is in suspended contact with a solvent or solvent system and the surfactant is suspended or dissolved in a solvent or solvent system, the reagent complex can be in suspended contact with a solvent or solvent system of the same or different composition as compared to the solvent or solvent system in which the surfactant is dissolved or suspended.
[0027] In some variations of the method for synthesizing metal nanoparticles, the reagent complex can be combined with surfactant in the absence of solvent. In some such cases a solvent or solvent system can be added subsequent to such combination. In other aspects, surfactant which is not suspended or dissolved in a solvent or solvent system can be added to a reagent complex which is in suspended contact with a solvent or solvent system. In yet other aspects, surfactant which is suspended or dissolved in a solvent or solvent system can be added to a reagent complex which is not in suspended contact with a solvent or solvent system.
[0028] The surfactant utilized in the method for synthesizing metal nanoparticles can be any known in the art. Usable surfactants can include nonionic, cationic, anionic, amphoteric, zwitterionic, and polymeric surfactants and combinations thereof. Such surfactants typically have a lipophilic moiety that is hydrocarbon based, organosilane based, or fluorocarbon based. Without implying limitation, examples of types of surfactants which can be suitable include alkyl sulfates and sulfonates, petroleum and lignin sulfonates, phosphate esters, sulfosuccinate esters, carboxylates, alcohols, ethoxylated alcohols and alkylphenols, fatty acid esters, ethoxylated acids, alkanolamides, ethoxylated amines, amine oxides, alkyl amines, nitriles, quaternary ammonium salts, carboxybetaines, sulfobetaines, or polymeric surfactants.
[0029] In some instances the surfactant employed in the method for synthesizing metal nanoparticles will be one capable of oxidizing, protonating, or otherwise covalently modifying the hydride incorporated in the reagent complex. In some variations the surfactant can be a carboxylate, nitrile, or amine. In some examples the surfactant can be octylamine.
[0030] The metal nanoparticles included in the electrode can have an average maximum dimension less than 100 nm. In some instances, the metal nanoparticles included in the electrode have an average maximum dimension less than 25 nm. In some instances, the metal nanoparticles included in the electrode have an average maximum dimension less than 10 nm. In some instances, the metal nanoparticles included in the electrode have an average maximum dimension of 5 nm or less. The metal nanoparticles included in the electrode are, in some variations, generally of uniform size and free of oxide. The metal nanoparticles included in the electrode can be obtained by the process for synthesizing metal nanoparticles, as disclosed above.
[0031] It will be appreciated that the disclosed electrode can, and frequently will, include additional structural and/or electrochemically active materials. For example, polytetrafluoroethylene (PTFE) can serve as a binder to facilitate metal nanoparticle dispersion, adhesion, or structural integrity. The disclosed electrode can include a substance such as carbon powder or carbon paper, to participate in electrochemistry or to serve as a structural substrate. It is to be understood that these are examples only, and that any suitable materials can be incorporated into the disclosed electrode along with the metal nanoparticles.
[0032] Thus, in one non-limiting example, discussed further below, an example electrode according to the present disclosure includes silver nanoparticles, obtained by the disclosed process for synthesizing metal nanoparticles. The silver nanoparticles are mixed with poly(vinylidene fluoride-co-hexafluoropropene) (PVdF-HFP) and (N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethylsulphonyl-imide) (DEME-TFSI) in N-methylpyrrolidone (NMP) and the mixture is cast on carbon paper.
[0033] Further disclosed is a metal-air battery having at least one electrode of the type described above. The metal-air battery will generally produce an electrical current via an electrochemical reaction in which a cation species originated from a metal anode reacts with oxygen through electron reduction or oxidation process. In some instances, the metal-air battery will be a lithium-air battery, in which electrical current is generated by an electrochemical reaction which includes the following: within which occurs during normal operation at least the following electrochemical reaction:
[0000] 2Li + +2 e − +O 2 Li 2 O 2 .
[0000] In some instances, the electrode as described above and included within the metal-air battery of the present disclosure will operate as a cathode-type electrode during discharge and charge.
[0034] In a non-limiting example (details of which are provided below), a lithium-air battery was prepared having a lithium anode and lithium bis(trifluoromethanesulfonyl)Imide (LiTFSI) dissolved in DEME-TFSI as an electrolyte. Six similar batteries were prepared in which the cathode had the silver nanoparticles of FIG. 2 (Example 1), μm scale commercially available silver particles (Comparative Example 1), nm scale commercially available silver nanoparticles (Comparative Example 2), no silver (Comparative Example 3), the commercial silver nanoparticles of Comparative Example 2, in admixture with carbon powder (Comparative Example 4), or the silver nanoparticles of Example 1 in admixture with carbon powder (Comparative Example 5).
[0035] The plot in FIG. 3 showing battery voltage as a function of the logarithm of current density demonstrates the superiority of the battery of the present disclosure as compared to the comparable batteries having commercially available silver particles on the cathode. The plot of initial charge/discharge profiles in FIG. 4 further indicates the superior charge/discharge properties of the battery according to the present disclosure. Finally, the current-voltage profiles of FIG. 5 , again represented by voltage as a function of logarithm of current density, indicate that the battery according to the present disclosure has superior performance when carbon is omitted from the cathode.
[0036] Various aspects of the present disclosure are further illustrated with respect to the following Examples. It is to be understood that these Examples are provided to illustrate specific embodiments of the present disclosure and should not be construed as limiting the scope of the present disclosure in or to any particular aspect.
[0037] In each of the examples below, an electrode is prepared as described, and then incorporated into a lithium-air battery opposite a lithium anode with 0.352 mol/kg LiTFSI in DEMETFSI which is immersed in glass filter separator (Whattman) and the battery is supplied with pure oxygen (99.99% in purity). The battery is a coin-type cell with air hole toward cathode side which is put in gas tight chamber.
[0038] A current was applied for 30 minutes and the potential was monitored. After 30 minute, the current was switched next in the range of 0.1 μA-1 mA. In FIGS. 3 and 5 , the potentials recorded after 30 minute were plotted as a function of logarithm of current density. For discharge-charge measurements, the current of 53 μA was applied and the cut-off voltage was 2.0 V and 3.5 V, respectively.
Example 1
Electrode Having Silver Nanoparticles Synthesized by the Disclosed Method
[0039] Silver powder (6.00 g) and lithium borohydride (2.44 g) are combined in a planetary ball mill. The combination is ball-milled for 4 hours at 160 rpm with stainless steel ball bearings. This produced particles of Ag.(LiBH 4 ) 2 complex, an XPS spectrum of which is shown in FIG. 1 . The reagent complex (5.58 g) is suspended in THF (100 mL) and octylamine (47.7 g) is added, and stirred for 4 hours to produce silver nanoparticles (XRD spectrum shown in FIG. 2 ). These silver nanoparticles were then washed with additional THF.
[0040] Ag nanoparticles obtained by the mechanochemical process above are mixed with PVdF-HFP (Alkema) and DEMETFSI ionic liquid (Kanto corporation) in the NMP (Aldrich) solvent, and then was cast on a carbon paper (Toray, TGP-H-60), and finally dried at 120° C. under vacuum. The weight ratio of Ag:PVdF-HFP:DEMETFSI to form an electrode was 30:15:55 (wt %).
Comparative Example 1
[0041] An electrode is compared as in Example 1, however commercially available μm scale Ag particles are used in place of the nanoparticles prepared by the mechanochemical method.
Comparative Example 2
[0042] An electrode is compared as in Example 1, however commercially available nanoparticulate Ag is used in place of the nanoparticles prepared by the mechanochemical method.
Comparative Example 3
[0043] An electrode is prepared as above, however no silver is used; carbon paper only (No Ag particle).
Comparative Example 4
[0044] An electrode is prepared as in Comparative example 1, except that Super P carbon black is included in the material cast on carbon paper. SuperP:Ag:PVdF-HFP:DEMETFSI=11:19:15:55 (wt %).
Comparative Example 5
[0045] An electrode is prepared as in Example 1, except that Super P carbon black is included in the material cast on carbon paper. SuperP:Ag:PVdF-HFP:DEMETFSI=11:19:15:55 (wt %).
[0046] The foregoing description relates to what are presently considered to be the most practical embodiments. It is to be understood, however, that the disclosure is not to be limited to these embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
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Electrodes for metal-air batteries and the metal-air batteries employing such electrodes are provided. The electrodes include metal nanoparticles synthesized via a novel route. The nanoparticle synthesis is facile and reproducible, and provides metal nanoparticles of very small dimension and high purity for a wide range of metals. The electrodes utilizing these nanoparticles thus may have superior capability. Electrochemical cells employing said electrodes are also provided.
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BACKGROUND OF THE INVENTION
This invention relates to a power transmission driveline unit for motor vehicles, and more prticularly to an automatic power transmission for a transaxle driveline arrangement for a vehicle in which the engine and the power output shafts which rotate the wheels extend in a direction generally transverse to the length of the vehicle. Such arrangements are used in vehicles having a forwardly mounted engine with front wheel drive or a rearwardly mounted engine with rear wheel drive.
SUMMARY OF THE INVENTION
Briefly, this invention comprises an automatic power transmission transaxle driveline unit for a motor vehicle.
One of the primary objects of this invention is to porvide a three forward speed and reverse drive motor vehicle transmission adapted for use with an engine which extends transversely of the vehicle.
Another object of the invention is to provide a transmission of the type described which extends transversely of the vehicle, and includes drive portions which extend in opposite directions;
A further object of this invention is to provide an automatic transmission such as described which is compact and adaptable to a multiplicity of different transversely extending engines;
Still another object of the present invention is the provision of an automatic transmission of the class described which is simple and economical in construction and efficient in operation.
Other objects and advantages of this invention will be made apparent as the description progresses.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings in which one of various possible embodiments in illustrated,
FIG. 1 is a schematic front elevational view of a motor vehicle drive train which includes an automatic power transmission unit embodying this invention;
FIG. 2 is an elevational view of a power transmission unit constructed in accordance with this invention with the case thereof broken away and shown in section for clarity; and
FIGS. 3U and 3L are enlarged sectional views of the upper and lower portions of FIG. 2 and should be considered together as two portions of one view.
Like parts are indicated by corresponding reference characters throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 of the drawings diagrammatically discloses a motor vehicle power plant and drive train comprising an internal combustion engine E mounted transversely of a vehicle between two wheels W, which wheels may be the front or rear wheels. The engine E is drivingly connected to a power transmission unit which includes a hydrokinetic type of torque converter device TC drivingly connected to a change speed gearbox B having a speed change section SC and a transfer section T. The output from the gearbox B is connected to a differential unit D which is drivingly attached to axles A attached to the wheels W.
FIGS. 2, 3U and 3L disclose the flow of power through the transmission unit that comprises torque converter TC, box B and differential D in a series connected drive transmitting relationship. The end portion of a driving member, such as the crankshaft of the engine E of the motor vehicle is indicated at 1. The shaft is drivingly connected to a drive transmitting ring 3 by fasteners 5 and the ring is connected to a torque converter casing 7 by bolts 9. An engine starter ring 11 is mounted on and extends around the periphery of drive ring 3.
The torque converter casing 7 contains the conventional turbine 8 and stator or reaction member 10 as well as the impeller 12, with the impeller 12 being integrally connected to the casing 7 and the turbine member 8 being drivingly connected by a hub 13 to a shaft 15. The stator or reaction member 10 is connected by a one-way brake device (having an inner hub 17) to an axial sleeve 19 secured to a wall or partition 21 attached to the interior of a housing 23. The construction of a torque converter of this type is well known and a detailed description of such construction or the operation thereof is unnecessary.
A gear type hydraulic pump 25 having a driving gear 27 is directly connected by a key 29 to the rearwardly projecting end of an axially extending sleevelike flange portion 31 of torque converter casing 7. The pump 25 draws fluid from a supply sump (not shown) through a conduit 33 and circulates fluid through the converter TC, the transmission lubricating system and the various hydraulically operated control mechanisms associated with this power transmission.
The gearbox B includes the forward drive clutch C 1 , the direct drive clutch C 2 and a pair of planetary gear trains 35 and 37 which are adapted to cooperate with the torque converter device TC to provide means for the transmission of three forward drives and a reverse drive to a speed change section output shaft 39. The forward drive clutch C 1 is engaged whenever any of the three forward speed is being utilized, and is disengaged when the transmissions controls are set in either Neutral or Reverse. The direct drive clutch C 2 is engaged only when the third Direct Forward Speed is being transmitted and whenever Reverse drive is being transmitted. The different clutches and brakes that are applied for transmitting the several drive ratios obtainable with this transmission are set forth in the chart below.
______________________________________Drive Ratio: Members Applied:______________________________________Low (first) C.sub.1 and B.sub.1 or O.W.B..sub.1Kickdown (second) C.sub.1 B.sub.2Direct (third) C.sub.1 C.sub.2Reverse C.sub.2 B.sub.1______________________________________
The gear box includes the housing 23 which may be considered to include the upper and lower portions, the speed change section SC and the transfer section T. In the front portion of the speed change section are located the clutches C 1 and C 2 and one planetary gear set 37 whereas the rear portion of the speed change section houses the planetary gear set 35 and an overrunning clutch O.W.B. 1 . The rear end of the converter driven gear box input shaft 15 pilots the forward end of the speed change section output shaft 39. Output shaft 39 has its rear end portion journalled in a bearing 41 located in the rear wall 43 of the speed change section. A speed change section output gear 45 is secured to the rearward end of shaft 39 for transferring the drive from the speed change section to the transfer section T. Section T will be described in detail hereinafter.
Transmission input shaft 15 is drivingly connected at 47 to a spider element 49 which carries the friction clutch disc elements 51 of the Reverse and Direct Drive clutch C 2 . The set of clutch discs 51 are adapted to be drivingly engaged with the use of clutch disc 53 which are drivingly connected to the interior surface of a brake drum 55. The brake drum 55 is journalled on the rearwardly projecting collar 57 on the gear box housing wall 21. A brake band B 2 is arranged to be selectively applied to the brake drum 55 to prevent rotation thereof. The brake drum mounts a backing plate 59 which cooperates with an axially shiftable piston 61 to effect drive transmitting engagement of the clutch discs 51 and 53. An angular spring 63 normally urges the piston 61 forwardly to clutch disengage position. Pressure fluid for operation of the clutch C 2 is supplied to the piston bore 65 for piston 61 through the conduit 67 which is connected to the hydraulically operated control system. The spider 49 also has a rearwardly extending clutch drum 69 at the periphery thereof. Clutch drum 69 has drivingly and shiftably mounted on its interior face one or more clutch discs 71. The clutch discs 71 are arranged to be drivingly engaged with the clutch discs 73 which are carried by the exterior surface of an annulus gear 75 of the forwardly arranged planetary gear set 37. Clutch discs 71 and 73 are arranged to be drivingly compressed against a backing plate 77 by a pressure plate member 79 actuated by a lever spring plate 81. Lever spring plate 81 is operated by a piston 83 which reciprocates in a cylinder bore 85 formed in the rear side of the spider element 49. Pressure fluid is supplied to the cylinder bore 85 through a conduit 87 connected to the hydraulically operated control system.
Arranged concentrically within the forward drive clutch C 1 is the forwardly located planetary gear set 37. This gear set comprise the annulus gear 75, a sun gear 87, planet pinion gearing 89 connecting gears 75 and 87, and a planet pinion gear carrier 91 which rotatably supports the pinion gearing. Carrier 91 is splined to the speed change output shaft 39 at 93. Annulus gear 75 is supported on an annular plate 97 rotatably mounted by bushing 99 on the hub portion of the carrier 91. The sun gear 87 is an integral part of a double sun gear sleeve 101, with the sun gear 87 being formed on the front end thereof and a sun gear 103 of the planetary gear set 35 being formed on the rear end thereof. Bearings 105 mount the sun gear sleeve 101 on the speed change section output shaft 39.
The rearwardly located gear set 35 includes the sun gear 103, and annulus gear 107, planet pinion gearing 109 which connects gears 103 and 107 and a planet pinion gear carrier 111 which rotatably supports pinion gearing 109. Annulus gear 107 is drivingly connected to the speed change section output shaft 39 by splines 113. Pinion gear carrier 111 is drivingly connected at 115 to a brake drum 117 adapted to be engaged by a brake band B 1 . Brake drum 117 is rotatably mounted on an annular ledge 119 secured to the rear wall 43 of the housing 23 by fasteners 121. The brake drum 117 is restrained against reverse rotation, counterclockwise when looking from the left towards the right of the transmission, by means of a conventional one-way brake device O.W.B. 1 .
Inter-connection between the two axially spaced adjacent gear sets 35, 37 is by way of the common sun gear sleeve 101 and by way of the dual connections of the front carrier 91 and the rear annulus gear 107 to the common speed change section output shaft 39. The drum 55 is connected by bell-shaped member 123 to the sun gear sleeve 101.
An end cover plate 125 forms a chamber 127 at the end of the housing 23 opposite to the end in which the torque converter is located. Gear 45 on the end of the speed change section output shaft 39 drives a transfer gear 129 mounted on the end of the transfer shaft 131 located in the transfer section T of housing 23. The transfer gear 129 is rotatably supported by bearings 133 in wall 43. The other end of the transfer shaft 131 is rotatably supported by bearings 135 in a sleeve 143.
A governor valve body 137 of a hydraulic governor device which forms part of the hydraulic control system is mounted on the transfer shaft 131 by a governor support 139 which is splined to the transfer shaft 131 and is rotatably mounted within sleeve 143. Suitable porting 145 extends through the body 137, support 139 and sleeve 143 to provide for the flow of hydraulic fluid to and from the governor valve body 137. An annular seal 147 is mounted on the inside of sleeve 143 and engages the transfer shaft 131.
The end of transfer shaft 131 opposite to that which the transfer gear 129 is attached is formed as a gear 149. Gear 149 drives an annular ring-shaped gear 151 secured by fasteners 153 to an annular flange 155 on a two-piece differential case or carrier 159. Each of the two pieces of carrier 159 includes an annular collar 160 extending transversely with respect to the vehicle. A bearing 161 supports one collar 160 in a housing member 163 and a bearing 165 supports the other collar 160 in a tubular member 167 located in an opening in a housing 169. The two-piece carrier 159 forms a differential chamber through which a shaft 171 extends. Pinions 173 and 175 are rotatably mounted on shaft 171 and engage side gears 177 and 179 which are respectively splined to output shafts 181 and 183. The output shafts 181 and 183 may be coupled by universal joints, such as indicated at 185 to the axles A connected to the wheels W.
With the aforesaid drive arrangement when the transmission is set in Neutral by proper positioning of the transmission shift selector mechanism (not shown), the hydraulic control system of the transmission prevents the application of the brake bands B 1 and B 2 . When the clutches C 1 and C 2 are disengaged, the torque converter-driven gearbox shaft 15 is disconnected from the planetary gear set 37 and from the gear sleeve 101 so there can be no drive input to either of the gear sets 35 and 37.
When the drive ratio selector mechanism (not shown) is set for initiation of drive in the Drive ratio the forward drive clutch C 1 is automatically engaged and this transmits drive to the annulus gear 75. Neither of the braking bands B 1 or B 2 nor the clutch C 2 is engaged at this time. The one-way brake O.W.B 1 prevents reverse rotation of the carrier 111 at this time and this one-way brake device provides the reaction for the compounded gear sets 35 and 37 which cooperate to transmit the one-way low or first speed forward drive to the speed change section output shaft 39. This low speed drive passes from the input shaft 15 through the engaged clutch C 1 and then to the annulus 75. Annulus gear 75 acts on the planet pinion gears 89 and causes rotation of the sun gear 87 backwards because the load on the speed change section output shaft 39 tends to anchor the planet pinion carrier 91 against rotation. Rotation of the sun gear 87 backwards rotates the sleeve 101 and the sun gear 103 backwards. The sun gear 103 rotating backwards acts on the planet pinions 109 and tends to rotate the pinion gear carrier 111 backwards because of the output shaft load on the annulus gear 107. Due to the one-way brake O.W.B. 1 the carrier 111 cannot be rotated backwards and the pinion gears 109 are then active to drive the ring gear 107 and connected speed change section output shaft 39 forwardly. Due to the connection of both the carrier 97 and the annulus gear 107 to the speed change section output shaft 39 and due to the anchoring of carrier 111 by the brake O.W.B. 1 , at this time part of the torque of the input shaft 15 is transmitted directly to the speed change section output shaft 39 by the planetary gear set 37 and the other part of the input shaft torque is delivered to the speed change section output shaft 39 through the compounded gear sets 37 and 35. The starting Low drive when the transmission is set for Drive, or any other forward drive ratio for that matter, passes through both of the gear sets 37 and 35 with the reaction normally provided by the one-way brake device O.W.B 1 . Gear 45 on the end of speed change section output shaft 39 rotates with such output shaft and rotates transfer gear 129 and the transfer shaft 131 connected to such transfer gear. Gear 149 on the opposite end of transfer shaft 131 rotates the ring gear 151, thereby rotating the case 159 the output shafts 181 and 183 are rotated in accordance with well known differential principles by the side gears 177 and 179.
The governor 137 rotates with transfer shaft 131 for controlling the fluid pressure which is utilized by the control system (not shown) for actuating the various clutches and servo mechanisms. It will be noted that the construction described permits the differential mechanism to be generally aligned in a vertical plane with the torque converter TC and the transfer Section T to be generally aligned in a vertical plane with the speed change section SC, thus providing a compact construction.
When Second speed is to be attained by an upshift from starting low, it is merely necessary to apply braking band B 2 while the forward drive clutch C 1 remains engaged. This anchors the rotatable sleeve 101 that carries the sun gears 87 and 103. With sun gear 103 anchored, the planetary gear set 37 is activated to directly transmit a forward Second speed drive from annulus 75 to pinions 89 to the speed change output shaft 39 by way of the carrier 91. The planetary gear set 35 is inactive at this time and its pinion carrier 111 is driven forwardly which causes it to overrun the one-way brake device O.W.B 1 . Braking band B 1 and clutch C 2 remain disengaged when the transmission is conditioned for Second speed for drive. It will be noted that no braking band need be released on an upshift from Low to Second because the Second speed can lift off the one-way brake O.W.B 1 when band B 2 is applied to activate Second speed and likewise no braking band need be applied on an automatic downshift from Second to Low for the drive can drop down onto the one-way brake device O.W.B 1 as the band B 2 is released.
The output from speed change section output shaft 39 is transmitted by gears 45 and 129 to the transfer shaft 131 and then by gears 149 and 151 to the differential mechanism.
Third forward speed or direct drive is achieved by an up-shift from Second that results from the engagement of the direct drive clutch C 2 on the release of the band B 2 . The forward drive clutch C 1 remains engaged when in third forward speed while bands B 1 and B 2 are each released. Engagement of the clutch C 2 while clutch C 1 is engaged connects the annulus gear 75 and the sun gear 87 of the planetary gear 37 and this locks up the gear set 37, thereby providing a direct 1:1 forward drive. Because of the interconnection of planetary gear set 37 with planetary gear set 35 by means of the sun gear sleeve 101 and the splines 113 for annulus 107, the two gear sets 35 and 37 are both locked up for the transmission of the third forward speed. The drive is then transmitted by the gears 45 and 129 to the transfer shaft 131.
Reverse drive is obtained by plaing the transmission selector lever (not shown) in a Reverse position. This action engages the clutch C 2 and applies the brake band B 1 , while the clutch C 1 is disengaged and the braking band B 2 is released. With the clutch C 1 disengaged there is no drive input to the annulus gear 75. Drive input is from the input shaft 15 to the clutch C 2 and drum 123 to the sun gear sleeve 101. As the braking band B 1 is applied to the carrier 111 is anchored and the annulus 107 is driven in a backwards or reversed direction by the gear set 35. Accordingly, the direction of rotation of gear 45 is reversed and this reverse rotation is transmitted through the gear 129 and transfer shaft 131 to the differential and axles A.
It will be seen that an automatic transmission as described lends itself to a compact construction which is advantageous for small front wheel drive vehicles, for example. The transmission is in essence folded upon itself with the final components, such as the governor and output gear 149 being mounted on a transfer shaft extending back in the direction toward the torque converter to provide a differential drive arrangement located in approximately the same generally vertical planer area as the torque converter TC.
In view of the foregoing it will be seen that the other objects and advantages of this invention are achieved.
Although only one embodiment of the invention has been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible.
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Automatic Power Transmission apparatus having output members extending in opposite directions to and generally parallel to the axis of rotation of the engine crankshaft. A transfer shaft has a gear on opposite ends thereof to transfer the output of one portion of the drive train back to another portion of the drive train which is located in general planar alignment with the input to the apparatus.
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