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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a division of co-pending U.S. patent application Ser. No. 10/250,299.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a windshield for motorcycles which is adjustably mounted by a holding means on the motorcycle and can be adjusted by a drive means into different positions.
[0004] The invention furthermore relates to a windshield for motorcycles which is adjustably mounted by a holding means on the motorcycle, the holding means having two non-parallel guides for setting different vertical and/or inclined positions of the windshield as it moves along the guides.
[0005] Finally, the invention relates to a drive means for an adjustably supported motor vehicle component, especially a windshield for motorcycles.
[0006] 2. Description of Related Art
[0007] German Patent DE 39 41 875 C1 discloses a windshield which is mounted on a motorcycle so as to be adjustable in its height and its angular orientation by an adjustment means. The adjustment means contains at least two guide rails arranged at different angles and on each of which a respective sliding piece is movably supported. The windshield is connected to the two sliding pieces to be able to pivot around the transverse axis of the vehicle. An electric motor is located in the area of the front, lower guide rail and via a threaded rod transfers linear drive motion to the sliding piece which is supported on the front guide rail. The driving of the sliding piece via the threaded rod or a comparable dimensionally stable drive element limits the possible locations of the electric motor in the vicinity of the front guide rail.
SUMMARY
[0008] A primary object of the present invention is to provide a windshield of the initially mentioned type with a drive device which is improved with respect to its arrangement and functionality.
[0009] Another object of the invention is to provide a windshield of the initially mentioned type with a holding means with two guides which is adjustably supported by a durable holding means with a simple structure.
[0010] A further object of the invention is to provide a drive means of simple structure for an adjustable vehicle component.
[0011] The initially mentioned object is achieved in accordance with the invention in that the drive means for the windshield has a cable line connection between the drive motor of the drive means and the adjustable windshield. A cable line connection which is formed, for example, in the manner of a Bowden cable, can be installed flexibly with bends or curvatures so that the drive means can be attached in the vicinity of the windshield or also farther away from it on the motorcycle without major structural limitations which entail rigid connecting elements, such as spindles or the like.
[0012] The initially mentioned object is also achieved in the initially mentioned windshield in accordance with the invention in that the drive means for the windshield has a lever means with at least one pivotally mounted drive lever between the drive motor of the drive means and the adjustable windshield. Rigid coupling by means of a pivotable drive lever enables reliable, play-free actuation and adjustment of the windshield. The lever ratios on the drive lever can be designed such that none of the drive movements applied to the drive lever are stepped up into large driven motions of the drive lever. This yields a compact execution of the drive unit.
[0013] If the drive means for the windshield has a lever means with two symmetrically arranged drive levers which are each connected on the outside end to a carriage, which is supported in the middle for pivoting in opposite directions, and which on the inner end are connected to one another by means of a movable coupling part, a uniform drive motion can be applied to two movable bearing parts of the windshield which are spaced apart from one another.
[0014] The second object is achieved by the first guide is mounted on the vehicle and the second guide being located on the windshield and by a driven carriage which is connected to the windshield on the first guide which is mounted on the vehicle and a vehicle-mounted part on the second guide located on the windshield being drive-engaged. Thus, both the vehicle-mounted part and also the windshield or the part connected to the windshield assume a guide function. Functionally, the carriage is connected via a cable line connection to the drive means. Here, the aforementioned advantages of the flexible arrangement of the drive means apply. A cable line connection is defined as any connections which are resistant to extension and compression, but which are flexible, and which can be flexible installed on the motorcycle, for example, in the manner of a Bowden cable.
[0015] Preferably, the windshield is mounted on the windshield bearing part which contains the second guide and which is connected to the carriage. In this configuration, the windshield bearing part forms a unit of the holding means and the windshield is interchangeably attached to the windshield bearing part and the holding means without effort.
[0016] If each cable line is guided to a respective one of a right-side and a left-side windshield bearing part or on two spaced mounting points on the windshield itself by the drive means, reliable adjustment of the windshield is ensured by this double driving.
[0017] Functionally, the drive means contains a rope pulley on which the cable or the rope of at least one cable or rope line can be wound and unwound. This pulley can have two adjacent peripheral grooves on which two cable lines can be wound and unwound at the same time and in the same direction so that the two cables, and thus the two windshield bearing parts, are synchronously activated. By means of one of the two cable line connections, at least one other movable part of the motorcycle can be adjusted synchronously to the motion of the windshield.
[0018] In one preferred embodiment, the guides are made as links in which stationary bearing elements, such as pins or the like, are guide-engaged. If the guides or links are formed to be linear, depending on the mutual assignment, a uniform adjustment motion is enabled. When the guides or links have at least one curved section, a pivoting motion of the windshield can be superimposed on the linear adjustment motion. Instead of the curved section, any shape of the guide or the link deviating from the linear section can make provide a pivoting motion of the windshield which deviates from the straight adjustment motion.
[0019] Preferably, the first guide or link is made in at least one longitudinal part of the holding means. This longitudinal part can be a central part of the holding means. Alternatively, there are two longitudinal parts in the right-side and left-side arrangement for the two windshield bearing parts.
[0020] Preferably, the longitudinal part is formed from at least two combined components which can be divided along the guide. This configuration facilitates the production of guides and the installation of the assigned components of the holding means, such as, for example, the carriage.
[0021] In the drive means for an adjustably supported vehicle component, especially a windshield for motorcycles, it is provided in accordance with the invention that the drive means has a cable line connection between the drive motor of the drive means and the vehicle component and a rope pulley on which at least one cable line can be wound and unwound and is guided by the drive means to the vehicle component or to a right-side and to a left-side vehicle component bearing part.
[0022] Furthermore, it is provided that the drive means has a lever means with at least one pivotally supported drive lever between the drive motor of the drive means and the adjustable vehicle component.
[0023] Further details of the configuration and advantages of the invention will become apparent from the following description taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a side view the front part of a motorcycle with an adjustable windshield;
[0025] FIG. 2 is a perspective view of the holding means of the windshield with a drive device in the initial position;
[0026] FIG. 3 is a view similar to that of FIG. 2 showing the drive device with the covering removed;
[0027] FIG. 4 is a view similar to that of FIGS. 2 & 3 showing the holding and drive device in the end position;
[0028] FIG. 5 is a perspective view of an inner side of the left-side part of the holding means;
[0029] FIG. 6 is a top view of the left-side part of the holding means and the drive device;
[0030] FIG. 7 shows in an inside view as shown in FIG. 5 , but with the holding means in the end position as shown in FIG. 4 ;
[0031] FIG. 8 is a perspective view from above of a second embodiment of a holding means of the windshield with a modified drive device in the initial position;
[0032] FIG. 9 is a view corresponding to that of FIG. 8 , but with the holding and drive device in the intermediate position;
[0033] FIG. 10 is a view corresponding to that of FIG. 8 , but with the holding and drive device in the end position;
[0034] FIG. 11 is a plan view of the holding means of the second embodiment in the initial position according to FIG. 8 ;
[0035] FIG. 12 is a plan view of the holding means in the intermediate position according to FIG. 9 ; and
[0036] FIG. 13 is a plan view of the holding means in the end position according to FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
[0037] The partially depicted motorcycle 1 of FIG. 1 has a cowling 2 and a windshield 3 which is mounted above the cowling 2 by a holding means 4 such that it can route the slipstream past the motorcycle driver 5 . If necessary, the windshield 3 can be adjusted in its height and/or its angle of inclination by the holding means 4 out of a most vertical set position (shown schematically in FIG. 1 in broken lines) into a highly inclined position (shown in solid lines).
[0038] The holding means 4 contains a holding frame 6 (only the part of the left part of which is shown in FIGS. 2 to 7 ) with mounting or screw openings 7 (see, FIGS. 5 & 8 ) for fixing the holding frame 6 on the frame of the motorcycle 1 or on the cowling 2 . A drive means 8 is mounted on the central transverse part 9 of the holding frame 6 . On the longitudinal side parts 10 (only the left longitudinal part 10 being shown), a linear link guide 11 (see, FIG. 4 ) with a, for example, rectangular cross section is formed in which an elongated carriage 12 is movably held. A front bearing pin 13 extends through a side oblong hole opening 14 of the link guide 11 into the bearing hole 15 of a windshield bearing part 16 . The carriage 12 is drive-engaged with a part, e.g., a stationary rear bearing pin 18 that projects on the back end 17 of the longitudinal part 10 , laterally to the outside, and fits into the link guide 19 of the windshield bearing part 16 which is formed as an oblong hole. The guides 11 , 19 are non-parallel with respect to each other, as is apparent from the drawings, for varying the position of the windshield 3 in terms of height and/or inclination, when it is moved along the guides. The rear bearing pin 18 is located above the link guide 11 , and the link guide 19 of the windshield bearing part 16 runs underneath the front bearing pin 13 so that the windshield bearing part 16 is swung up around the bearing pin 13 if it is pushed lengthwise by means of the driven carriage 12 and the bearing pin 13 . The windshield bearing part 16 has mounting openings 20 for attaching the windshield 3 .
[0039] Next to the link guide 11 and parallel to it, a channel 21 is formed, which connects with the opening 14 of the link guide 11 (see FIG. 5 to 7 ) and in which a drive cable 22 , which is connected to the carriage 12 , is movably held. The drive cable 22 is movably guided in jacketing 23 from the windshield bearing part 16 , via a bend 24 , to the pulley 25 of the central drive means 8 . The pulley 25 is mounted on the gear shaft of the force transmission mechanism 27 driven by the electric motor 26 (see especially FIG. 3 ), and has a peripheral groove 28 in which the drive cable 22 can be wound and unwound and which is resistant to tension and compression. By means of a retaining pin 29 which is mounted on the end of the drive cable 22 and which is inserted in a recess of the rope pulley 25 , the drive cable 22 is attached to the pulley 25 in the peripheral direction, resistant to extension. The pulley 25 has a second peripheral groove 30 next to the first peripheral groove 28 in which, in the same direction of rotation, a second drive cable 31 for the opposing, right-side windshield bearing part (not shown) is located. The covering 32 (see FIG. 2 ) covers and seals the pulley 25 .
[0040] Next to the link guide 11 and parallel to it, a channel 21 is formed, which connects with the opening 14 of the link guide 11 (see FIG. 5 to 7 ) and in which a drive cable 22 , which is connected to the carriage 12 , is movably held. The drive cable 22 is movably guided in jacketing 23 from the windshield bearing part 16 , via a bend 24 , to the pulley 25 of the central drive means 8 . The pulley 25 is mounted on the gear shaft of the transmission 27 driven by the electric motor 26 (see especially FIG. 3 ), and has a peripheral groove 28 in which the drive cable 22 can be wound and unwound and which is resistant to tension and compression. By means of a retaining pin 29 which is mounted on the end of the drive cable 22 and which is inserted in a recess of the rope pulley 25 , the drive cable 22 is attached to the pulley 25 in the peripheral direction, resistant to extension. The pulley 25 has a second peripheral groove 30 next to the first peripheral groove 28 in which, in the same direction of rotation, a second drive cable 31 for the opposing, right-side windshield bearing part (not shown) is located. The covering 32 (see FIG. 2 ) covers and seals the pulley 25 .
[0041] When the electric motor 26 is actuated, for example, via a hand switch on the handlebars or via a speed-dependent or slipstream-dependent control, the drives cables 22 , 31 are taken up at the same time from the position shown in FIG. 1 in which the two windshield bearing parts 16 are located in the front position and hold the windshield 3 in the lower vertical position with a slight upward inclination, via rotation of the cable pulley 25 so that, via rearward displacement of the respective carriage 12 , the windshield bearing parts 16 , and thus the windshield 3 , are raised and inclined more dramatically against the slipstream. The end position is shown in FIGS. 4 & 7 .
[0042] The opposing drive motion of the electric motor 26 moves the windshield 3 back again into the reclined position or into an intermediate position.
[0043] If the link guide 11 is positioned so that it rises over its length relative to the lengthwise axis of the motorcycle, the front bearing pin 13 , and thus the windshield bearing part 16 and the windshield 3 , are additionally raised in its vertical position.
[0044] One or both link guides 11 , 19 can have angled or curved sections so that a certain swinging behavior of the windshield 3 which is dependent on the lengthwise displacement can be fixed.
[0045] The largely flexibly installable drive cables 22 , 31 of the drive means 8 enable a comparatively free arrangement of the drive means 8 relative to the movable holding means 4 or to the windshield 3 so that the electric motor 26 with the transmission 27 and the pulley 25 can also be located away from the holding means 4 and at angular positions to it, which is something which could be accomplished by a conventional mechanical coupling only with high construction cost.
[0046] In another embodiment of the windshield (see, FIGS. 8 to 13 ), with a modified drive means, the holding means 4 contains a drive pulley 33 (see FIG. 11 ) which is located on the central transverse part 9 in the middle between the two side longitudinal parts 10 (only the left longitudinal part 10 is shown) and is pivotally supported on it and is coupled to rotate with the electric motor 26 via the transmission mechanism 27 . The drive wheel 33 is covered by a cover 34 which is mounted on the transverse part 9 . The carriage 12 of the windshield bearing part 16 is U-shaped and sits movably on the guide 11 which is formed as a rail. On the two brackets 35 , which project inward from the carriage 12 , a pin 36 is mounted on which a left drive lever 37 is pivotally supported. The drive lever 37 extends roughly to the middle of the transverse part 9 , resting directly on the cover 34 , and supported to move and pivot on a pin 38 which projects upward, for example, from the cover 34 and which is held to be able to move into an elongated hole 39 in the drive lever 37 .
[0047] A right drive lever 40 for driving the right windshield bearing part or its carriage is located symmetrically to the left drive lever 37 and is supported in the corresponding manner by means of a pin 42 which fits into the longitudinal slot 41 . The right drive lever 40 has an inner end 43 which is bent up such that this end 43 rests on the inner end 44 of the left drive lever 37 . The inner ends 43 , 44 of two drive levers 37 , 40 , each contain a longitudinal guide slot 45 , 46 in which is held a movable coupling part, e.g., the guide pin 47 which is mounted on a sliding piece 48 which is movably supported in a longitudinal guide 49 on the cover 34 . A drive part, e.g., a guide pin 50 which is eccentrically mounted on the drive wheel 33 extends through an arc-shaped slot 51 in the cover 34 (which defines a circular path) up into the longitudinal guide slot 45 in the drive lever 37 (as shown) or into the lengthwise hole 46 of the right drive lever 40 .
[0048] A right drive lever 40 for driving the right windshield bearing part or its carriage is located symmetrically to the left drive lever 37 and is supported in the corresponding manner by means of a pin 42 which fits into the longitudinal slot 41 . The right drive lever 40 has an inner end 43 which is bent up such that this end 43 rests on the inner end 44 of the left drive lever 37 . The inner ends 43 , 44 of two drive levers 37 , 40 , each contain a longitudinal guide slot 45 , 46 in which is held the guide pin 47 which is mounted on a sliding piece 48 which is movably supported in a longitudinal guide 49 on the cover 34 . A pin 50 which is eccentrically mounted on the drive wheel 33 extends through an arc-shaped slot 51 in the cover 34 up into the longitudinal guide slot 45 in the drive lever 37 (as shown) or into the lengthwise hole 46 of the right drive lever 40 .
[0049] To change the position of the windshield 3 , the drive means 8 causes the drive wheel 33 to rotate and swings the windshield 3 , for example, by an angle of a maximum roughly 130° clockwise as shown in FIGS. 8 to 13 . In doing so, the pin 50 , which slides in the longitudinal guide slot 45 , pivots the left drive lever 37 around the pin 38 so that the drive lever 37 moves the carriage 12 , and thus, the left windshield bearing part 16 to the rear via the middle intermediate position shown in FIGS. 9 & 12 into the end position which is shown in FIGS. 10 & 13 and in which the windshield 3 is raised to have a greater inclination.
[0050] As a result of the pin 50 which couples the two drive levers 37 , 40 to one another, the drive motion is transferred to the two drive levers 37 , 40 for their synchronous movement.
[0051] This embodiment has a small installation depth of the drive, since the drive motion takes place via the drive lever which pivots through only a comparatively small angle. The rotary motion of the pin 50 in the vicinity of the two end positions causes only minor pivoting of the two drive levers 37 , 40 , so that starting and braking take place gently in the vicinity of the two end positions.
[0052] The drive means 8 is controlled via Hall sensors in the drive motor and/or via microswitches which are triggered via the drive wheel 33 . There can also be a comparable control in the first embodiment.
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A windshield for motorbikes which can be variably positioned at various angles of inclination on the motorbike by a holding device ( 6 ) and a drive device ( 8 ). The drive device ( 8 ) has a cable or a cable pull connection ( 22, 23, 24, 25 ) between a drive motor ( 26 ) of the drive device ( 8 ) and a support element ( 16 ) for the adjustable windshield. The holding device ( 6 ) can also be formed by two non-parallel guides ( 11, 19 ) for varying the position of the windshield ( 3 ) in terms of height and/or inclination, when it is moved along the guides ( 13, 19 ). The first guide ( 11 ) is fixed to the vehicle and the second guiding mechanism ( 19 ) is arranged on the windshield ( 3 ). A driveable carriage ( 12 ) which is connected to a support element ( 16 ) for the adjustable windshield and is situated on the first guide ( 11 ) engages a part ( 18 ) which is fixed to the vehicle and is situated on the second guide ( 19 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an ignition timing control system for an internal combustion engine which uses a hybrid fuel containing alcohol.
2. Description of the Prior Art
For controlling the exhaust gases emitted by an automobile engine, it is a common practice to install a catalytic converter such as a three-way catalyst in the engine exhaust system. For coping with the fact that the catalysts including of this type of converter are inactive below a certain temperature, it is also a common practice to employ a system for quickly activating the catalyst after a cold engine start by retarding the ignition timing and thus quickly raising the exhaust gas temperature when the engine coolant temperature is low.
However, in such systems, a problem arises when the engine uses a fuel containing an alcohol such as methyl alcohol. Since the combustion temperature of alcohols is lower than that of gasoline, the temperature of the exhaust gas decreases with increasing alcohol concentration of the fuel. This slows the heating of the catalyst and thus delays its activation, with the result that the quality of the exhaust emissions is degraded.
SUMMARY OF THE INVENTION
This invention was accomplished for overcoming this problem and its object is to provide a system which prevents degradation of exhaust emissions in an engine using a fuel containing alcohol by controlling the ignition timing so as to quickly raise the catalyst temperature.
For realizing these objects, the present invention provides a system for controlling ignition timing of an internal combustion engine having a catalytic converter in its exhaust system and using a gasoline-alcohol blend fuel. The system comprises first means for detecting alcohol concentration in the fuel and control means for determining an ignition timing of the engine, wherein the control means retarding the ignition timing in response to the detected alcohol concentration.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the invention will be more apparent from the following description and drawings, in which:
FIG. 1 is an overall schematic view of an ignition timing control system for an internal combustion engine according to the invention;
FIG. 2 is a flow chart showing the operation of the system shown in FIG. 1;
FIG. 3 is a graph showing the characteristics of a look-up table(s) of a target retard amount IGrn defined with respect to the alcohol concentration VALC and the coolant temperature TW;
FIG. 4 is a graph showing the characteristics of a look-up table(s) of a correction value IGrnd for the target retard amount IGrn defined with respect to the intake manifold pressure PB; and
FIG. 5 is a graph showing the characteristics of a look-up table of a correction coefficient KTA for a basic value IGrx of an actual retard amount IGr defined with respect to the intake air temperature TA.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, reference numeral 10 designates a main unit of an internal combustion engine. Fuel containing methanol or some other alcohol is supplied from a fuel tank 12 via a fuel line 14 to a fuel injection nozzle 16 installed in an air intake manifold 18 of the main engine unit 10. A catalytic converter 20 such as a three-way catalyst is installed in an exhaust pipe 22 of the main engine unit 10.
The amount of fuel injected by the fuel injection nozzle 16 and the ignition timing are controlled by a controller 26 including a microcomputer. The controller 26 receives detection signals representing the engine speed Ne, the coolant temperature TW and the crank angle θcr from a engine sensor unit 28 that is mounted on the engine and includes a number of different kinds of sensors. It also receives a detection signal representing the throttle opening degree θth from a throttle position sensor 30, a detection signal representing the intake manifold pressure PB from a manifold absolute pressure sensor 32, a detection signal representing the oxygen content VO 2 of the exhaust gas from an oxygen content sensor 34, a detection signal representing the alcohol content VALC of the fuel from an alcohol concentration sensor 36 mounted in the fuel line 14, a detection signal representing the intake air temperature TA from a manifold air temperature sensor 38, and a detection signal representing the traveling speed V, of a vehicle on which the engine main unit 10 is mounted, from a vehicle speed sensor 40. Based on these signals, the controller 26 calculates the amount of fuel to be injected and the ignition timing IG. The ignition timing IG is calculated as
IG=IGi-IGr+A
where ignition advance is defined as being positive, IGi is a basic ignition timing retrieved from a look-up table(s) using Ne and PB and VALC as address data, IGr is an ignition retard amount calculated in the manner explained below, and A is a term representing various corrections. The data are predetermined separately for respective alcohol concentrations.
FIG. 2 is a flow chart showing the operation of the system shown in FIG. 1, in particular showing the determination procedures of a subroutine for calculating the retard amount IGr.
In step S1 through step S4 it is checked if the current operating condition is such that the ignition timing may be retarded.
More specifically, it is checked in step S1 if the engine speed Ne is at or above a prescribed value Nes. This is done because retarding the ignition timing will make the engine rotation unstable if the engine speed is too low. If it is found that Ne<Nes, control passes to step S5 in which the value of IGrx, the basic value used in calculating the aforesaid retard amount IGr, is set to zero, and no retard processing is conducted. The prescribed value Nes includes hysteresis. For example, it is initially set at 1,000 rpm, but once the engine speed Ne exceeds this value, the engine speed Ne is judged to be not less than the prescribed value Nes down to a lower value of, say, 950 rpm. If Ne≧Nes, control passes to step S2.
In step S2, it is then checked if a high-load increased fuel injection flag Fwot (the bit of which is set to 1 when the amount of fuel injected is increased under high load) is set to zero and, if the result is negative (if Fwot=1), control passes to step S5 and retard processing is not conducted. This is done because retarding the ignition timing when the flag Fwot=1 degrades the acceleration performance of the engine. When the flag Fwot=0, control passes to step S3.
In step S3, it is checked if an idle feedback flag Ffb (whose bit is set to 1 when feedback control is conducted for maintaining a constant idling speed) is set to zero and, if the result is negative (Ffb=1), control passes to step S5 and retard processing is not conducted. This is done because processing for retarding the ignition timing conducted while the flag Ffb=1 disturbs the feedback control and causes the engine rotation to become unstable. When the flag Ffb=0, control passes to step S4.
In step S4, a discrimination is still made as to whether or not the vehicle speed V is at or above a reference speed Vs set at a very low value (e.g. 5 km/h ), and if V<Vs, control passes to step S5 and retard processing is not conducted. This is done because the inertial force of the vehicle body is not large enough to stabilize the engine rotation when V<Vs, so that retarding the ignition timing under this condition would cause the engine rotation to become unstable. When V≧Vs, control passes to step S6.
The retard processing is conducted from step S6 onward. In step S6, the coolant temperature TW and the alcohol concentration VALC are used as address data for retrieving from a look-up table(s) of a target retard amount IGrn that corresponds to the values of TW and VALC at that instant. So as to compensate for the decrease in exhaust gas temperature with increasing value of VALC and thus to improve the temperature increase characteristics of the catalytic converter 20, the characteristics of the table is arranged such that the target retard amount IGrn increases with increasing alcohol concentration VALC, as shown in FIG. 3. Further, so as to compensate for the lower exhaust gas temperature while the engine is running cold, the table is arranged such that the target retard amount IGrn increases with decreasing coolant temperature TW.
Moreover, when the intake manifold pressure PB decreases (increases in negative pressure value) owing to reduced engine load, the amount of fuel injected also decreases, lowering the exhaust gas temperature. Since it is preferable to compensate for this temperature drop, in step S7 the target retard amount IGrn is corrected for the intake manifold pressure PB. This correction is conducted by using the manifold pressure PB for retrieving a correction value IGrnd from a correction table and adding the retrieved value to the target retard amount IGrn. FIG. 4 shows the characteristics of the table. As illustrated, the value IGrnd is zero during high load operation when the manifold pressure PB is at or over a prescribed upper limit value PBH (e.g. -99 mmHg in negative pressure), increases as the manifold pressure PB decreases below the upper limit value PBH, and then becomes a prescribed fixed value during low load operation when the manifold pressure PB is lower than a prescribed lower limit value PBL (e.g. -450 mmHg in negative pressure).
Control then passes to step S8 in which a prescribed unit amount delta IGr is added to the basic value IGrx in the preceding cycle to obtain that for the current cycle, and to step S9 in which the so-obtained value IGrx is compared with the target retard amount IGrn. The unit amount delta IGr is added to the value IGrx in each succeeding cycle until the value IGrx becomes larger than the target retard amount IGrn, at which time the value IGrx is replaced with the target retard amount IGrn in step s10. In other words, the value IGrx is progressively incremented until the target retard amount IGrn is reached.
Next, in step S11, a correction coefficient KTA related to the intake air temperature TA is retrieved from a table, and, in step S12, the aforesaid actual retard amount IGr is calculated as the product of the value IGrx and the coefficient KTA. As the intake air temperature TA decreases, the air-fuel mixture becomes increasingly difficult to ignite. Thus at lower intake air temperatures, retarding the ignition timing leads to an increase in the amount of unburned components in the exhaust gas, namely to more harmful exhaust emissions. Therefore, as shown in FIG. 5, the characteristics of the KTA table is arranged such that the coefficient KTA is zero and, accordingly, the retard amount IGr is zero, when the temperature TA is at or below a prescribed lower limit value TAL (e.g. 10° C.). Between the lower limit value TAL and a prescribed upper limit value TAH (e.g. 25° C.), the coefficient KTA increases from zero to 1 as the temperature TA increases.
The ignition timing IG will be calculated on the basis of the retard amount IGr obtained in the foregoing manner. Conducting ignition at this ignition timing prevents lowering of the exhaust gas temperature, in this way promoting the reactions in the catalytic converter 20.
The present invention has thus been shown and described with reference to the specific embodiments. However, it should be noted that the present invention is in no way limited to the details of the described arrangements, but changes and modifications may be made without departing from the scope of the appended claims.
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An ignition timing control system for an internal combustion engine having a catalytic converter in its exhaust system and using a gasoline-alcohol blend fuel. Since the combustion temperature of the alcohols is lower than that of gasoline, the temperature of the exhaust gas decreases with increasing alcohol concentration of the fuel, which slows the heating of the catalyst and thus delays its activation, thereby degrading exhaust emission. In order to avoid this, ignition timing is retarded at cold engine starting with increasing alcohol concentration in the fuel so as to raise the exhaust gas temperature and promote the reactions in the catalytic converter. The retard amount is further adjusted by the manifold pressure and the intake air temperature.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 10/119,298 filed Apr. 10, 2002.
[0002] This application claims the priority of German Application No. 101 18 067.5 filed Apr. 11, 2001, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] This invention relates to a device for a fiber processing machine such as a carding machine or a roller card for evening the fiber web or sliver produced thereby. The fiber processing machine may be preceded by a fiber tuft feeder which has a feed chute and further includes a feeding device composed of a feed roll and a feed tray which directly cooperate with an opening roll (such as a preliminary roll in a roller card and a licker-in in a carding machine) of the fiber processing machine. The lower end of the feed chute terminates in the region of the feed roll in such a manner that the feed roll draws the fiber material from the feed chute.
[0004] In a known device, such as disclosed in European Patent No. 468,985, a carding machine is fixedly connected with an upstream-arranged tuft feeder. The housing of the tuft feeder accommodates a feed chute which continues, without the interposition of delivery rolls, as a hopper slide, by means of which the fiber material (fiber batt) is advanced to the carding machine. The feed roll cooperates with the fixed-axis licker-in of the carding machine. Setting the distance between a clamping location defined by the cooperating feed roll and feed tray and a combing location (which is the location where the fiber material is transferred to the opening roll) is not contemplated by the prior art structure.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to provide, in a fiber processing system, an improved device of the above-outlined type with which the distance between the clamping and transfer locations may be altered in a simple manner, making possible an improved processing of the fiber material.
[0006] This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber processing system includes a first roll; a feed tray forming a feeding device with the first roll and defining a clamping location therewith for clamping and advancing fiber material; a second roll cooperating with the feeding device for taking over the fiber material therefrom at a transfer location on the second roll; a third roll cooperating with the second roll for taking over the fiber material from the second roll; and an adjusting arrangement for varying a distance between the clamping and transfer locations. The adjusting arrangement includes a pivoting device for arcuately displacing the second roll about the rotary axis of the first roll or the third roll; and a shifting device for displacing the feeding device toward or away from the third roll.
[0007] By virtue of the fact that, as viewed in the direction of fiber processing, the opening roll adjoining the feeding device may be swung about the axis of an immediately adjoining roll, the transfer location may be changed, whereby the distance between the clamping location and the transfer location is altered as well. Thus, a distance adjustment is feasible which is of primary importance for a gentler and more uniform feed of the fiber material. In particular, an advantageous adaptation of the distance to the properties (particularly the fiber length) of the processed fiber material is feasible by setting the distance as a function of such properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a schematic side elevational view of a roller card, preceded by a roller card feeder.
[0009] [0009]FIG. 2 is a schematic side elevational view of a preferred embodiment of the invention in which the opening roll, cooperating with the feed roll, is pivotal about the rotary axis of the feed roll.
[0010] [0010]FIGS. 3 a and 3 b are schematic side elevational views, in two different operational positions, of a further preferred embodiment of the invention in which the opening roll, cooperating with the feed roll, is pivotal about the rotary axis of an immediately consecutive opening roll.
[0011] [0011]FIGS. 4 a, 4 b and 4 c are schematic side elevational views showing initial, intermediate and end positions of the pivotal opening roll of the FIG. 2 embodiment.
[0012] [0012]FIGS. 5 a , 5 b and 5 c are schematic side elevational views showing initial, intermediate and end positions of the pivotal opening roll of the embodiment shown in FIGS. 3 a , 3 b.
[0013] [0013]FIG. 6 is a schematic partial view of a carding machine incorporating another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] [0014]FIG. 1 shows a roller card 1 in which the processed fiber advances in the direction A. Upstream of the roller card 1 —as viewed in the fiber processing direction A—a roller card feeder 31 is arranged which may be, for example, a SCANFEED model manufactured by Trützschler GmbH & Co. KG, Mönchengladbach, Germany. The feeder 31 has a housing 27 which is provided with wheels 28 a , 28 b for displacing the feeder 31 on the supporting floor in the direction of the arrows B, C. The feeder 31 further includes a vertical reserve chute 2 supplied from above with a flow I composed of air and finely opened fiber, advanced in a supply and distributor conduit 3 . In the upper region of the reserve chute 2 air outlet openings 4 ′, 4 ″ are provided through which the conveying air stream II enters into a suction device 5 after the fiber tufts III have been separated from the stream II. A slowly rotating delivery roll 6 at the lower end of the reserve chute 2 advances the fiber material in cooperation with a feed tray 7 from the reserve chute 2 to a rapidly rotating opening roll 8 which is provided with a pin or sawtooth clothing. A circumferential portion of the opening roll 8 borders the entrance at the upper end of a downwardly extending feed chute 9 into which the opening roll 8 advances the fiber material. At the lower, outlet end of the feed chute 9 a slowly rotating delivery roll 10 is provided which, in cooperation with a feed tray 14 , advances the fiber material to the roller card 1 .
[0015] The walls forming the feed chute 9 are, in the region of their lower portion and up to a certain height, provided with air outlet openings 11 ′, 11 ″. For uniformly densifying and maintaining constant the discharged fiber quantities, at the upper, entrance end the feed chute 9 communicates with an air passage 12 coupled to a blower. As a result, the fiber material is exposed to an air stream at the delivery roll 6 from the air passage 12 , so that an air/fiber tuft mixture IV advances in the feed chute 9 . The air is withdrawn at the lower part of the feed chute 9 through the air outlet openings 11 ′, 11 ″. The fiber material is continuously introduced into the feed chute 9 at a predetermined flow rate by the feed roll 6 and the opening roll 8 , and the fiber material is discharged at the same flow rate from the feed chute 9 by the delivery roll 10 and the feed tray 14 . The feed tray 14 is composed of a series of individual feed tray elements rotatable about pivot 15 of a tray support structure 13 which, in turn, is mounted on the inside of the housing 27 of the feeder 31 . The delivery roll 10 and the feed tray 14 of the feeder 31 form a feeding device for supplying the fiber material (fiber batt) directly to the roller card 1 . For this purpose the feeder 31 is, from its position shown in FIG. 1, rolled to the immediate vicinity of the roller card 1 .
[0016] The feeding device 10 , 14 is followed in the working direction A by a first preliminary roll 16 1 , a second preliminary roll 16 2 , a preliminary cylinder 17 (licker-in), a transfer roll 18 , a main cylinder 19 , a doffer 20 and a stripping roll 21 . With the licker-in 17 two roll pairs and with the main cylinder 19 six roll pairs cooperate, each being formed of a working roll 25 and a reversing roll 26 . The stripping roll 21 is adjoined by and is cooperating with two calender rolls 22 , 23 . All the above-noted rolls of the roller card 1 rotate at high circumferential velocities.
[0017] Turning to FIG. 2, the feed tray 14 ′ is positioned above the feed roll 10 which rotates in the direction 10 a. The feed roll 10 is followed by an opening roll 16 rotating in the direction 16 a . These two directions of rotation are opposite to one another so that along the cooperating circumferential regions of the two rolls the latter move in the same direction. In this arrangement the opening roll 16 of FIG. 2 functions as the roll 16 1 of FIG. 1 and directly transfers fiber material to the preliminary drum 17 , whereby the second opening roll 16 2 of FIG. 1 is advantageously dispensed with.
[0018] The preliminary roll 16 is arranged for pivotal adjustment about the rotary axis M 1 of the feed roll 10 . For this purpose, one end of a lever 29 is mounted on the shaft of the feed roll 10 and the opposite end of the lever 29 is mounted on the shaft or supporting bracket of the preliminary roll 16 . By means of this construction the lever 29 may pivot in the direction of the arrows D, E about the axis M 1 of the feed roll 10 , and thus likewise, the preliminary roll 16 may swing about the axis M 1 . In this manner the distance between the clamping location (that is, the smallest distance between the feed roll 10 and the feed tray 14 ′) and the transfer location (that is, the smallest distance between the feed roll 10 and the preliminary roll 16 ) is changed. During the arcuate displacement of the axis M 2 of the preliminary roll 16 about the axis M 1 of the feed roll 10 , the distance between the non-illustrated clothings of the feed roll 10 and the preliminary roll 16 remains constant. In this construction the preliminary roll 16 is a structural component of the roller card feeder 31 .
[0019] Turning to the embodiment shown in FIGS. 3 a and 3 b , the feeding device (composed of the feed roll 10 and the feed tray 14 ) of the roller card feeder, as well as the preliminary rolls 16 1 and 16 2 of the roller card are arranged in series. In this embodiment the preliminary roll 16 1 is arranged to swing about the axis M 3 of the subsequent preliminary roll 16 2 . For this purpose the two rolls 16 1 and 16 2 are coupled to one another by a lever 30 in a manner similar to the connection between rolls 10 and 16 by the lever 29 of the FIG. 2 embodiment. The lever 30 is pivotal in the direction of the arrows G, H about the axis M 3 . In this manner, the preliminary roll 16 1 may swing about the rotary axis M 3 of the preliminary roll 16 2 . By rotation in the direction of the arrow G, the distance e 1 according to FIG. 3 a is increased to e 2 according to FIG. 3 b , that is, the distance between the clamping location defined by the components 10 and 14 and the transfer location between the components 10 and 16 1 is adjustable. Further, a change of at least some of the distances a 1 , b 1 , c 1 and d 1 shown in FIG. 3 a to distances a 2 , b 2 , c 2 and d 2 shown in FIG. 3 b results from a displacement of the feeding device 10 , 14 by rolling the roller card feeder 31 toward the roller card 1 (FIG. 1) in the direction of the arrow F. The swinging and shifting motions of the rolls will be described in further detail with reference to FIGS. 4 a , 4 b , 4 c and 5 a , 5 b , 5 c which relate to the two embodiments shown in FIG. 2 and in FIGS. 3 a , 3 b , respectively.
[0020] In FIGS. 4 a , 4 b and 4 c the preliminary roll 16 1 is arcuately displaceable about the axis M 1 of the feed roll 10 as shown in FIG. 2. FIG. 4 a shows the starting position of the feeding device (feed roll 10 and feed tray 14 ) and the preliminary rolls 16 1 and 16 2 (in FIG. 2 the preliminary roll 16 2 was omitted). In a first step, according to FIG. 4 b , the preliminary roll 16 1 is swung in the direction D about the axis M 1 of the feed roll 10 . As a result, the distance between the clothings of the preliminary rolls 16 1 and 16 2 and the distance between the clamping and transfer locations defined by the feeding device 10 , 14 and the roll 16 1 rolls increases. In order to reestablish the required initial distance between the clothings of the preliminary rolls 16 1 and 16 2 shown in FIG. 4 a , in a second step according to FIG. 4 c , the feeding device 10 , 14 is, together with the preliminary roll 16 1 , shifted in the direction F toward the preliminary roll 16 2 by rolling the feeder 31 toward the roller card 1 as noted earlier. As a result, the distance between the clamping location defined by the feed roll 10 and the feed tray 14 and the transfer location defined by the feed roll 10 and the preliminary roll 16 1 is enlarged, while the distance between the rolls 10 and 16 1 and between the rolls 16 1 and 16 2 remains the same, as may be seen by a comparison between FIGS. 4 a and 4 c.
[0021] In FIGS. 5 a , 5 b and 5 c an arcuate displacement of the preliminary roll 16 1 about the axis M 3 of the preliminary roll 16 2 is shown in accordance with the embodiment illustrated in FIGS. 3 a and 3 b . In FIG. 5 a the initial position of the feeding device (feed roll 10 , and feed tray 14 ), the preliminary roll 16 1 and the preliminary roll 16 2 is shown. In a first step according to FIG. 5 b , the feeding device 10 , 14 is shifted in the direction of the arrow I away from the preliminary roll 16 1 by rolling the feeder 31 away from the roller card 1 (FIG. 1). As a result, the distance between the clothings of the feed roll 10 and the preliminary roll 16 1 is increased. In order to reestablish the required initial distance between the feed roll 10 and the preliminary roll 16 1 according to FIG. 5 a , in a second step according to FIG. 5 c the preliminary roll 16 1 is swung in the direction of the arrow H about the axis M 3 of the preliminary roll 16 2 . In this manner, the distance between the clamping location defined by the feed roll 10 and the feed tray 14 and the transfer location defined between the feed roll 10 and the preliminary roll 16 1 is reduced as compared to that shown in FIG. 5 a and also, the distance between the two rolls 10 and 16 1 is re-established.
[0022] While in the preceding description the invention was set forth in connection with a roller card and roller card feeder, it will be understood that in the same manner a mobile card feeder (incorporating the feeding device 10 , 14 ) and a carding machine may be used.
[0023] [0023]FIG. 6 shows an embodiment in which the feeding device 10 , 14 is an integral part of the fiber processing machine, such as a schematically and partially shown carding machine CM. The feeding device 10 , 14 is followed by three licker-ins 16 3 , 16 4 and 16 5 . The feeding device 10 , 14 receives the fiber tufts as a fiber batt from, for example, a non-illustrated card feeder and advances the fiber material to the licker-in 16 3 . The fiber material is then consecutively transferred to the licker-ins 16 4 and 16 5 and the latter transfers the fiber material to the main carding cylinder 35 . For varying, according to the invention, the distance between the clamping location defined by the feed roll 10 and the feed tray 14 and the transfer location at the licker-in 16 3 , the latter may be swung either about the rotary axis of the feed roll 14 as described in connection with FIGS. 2, 4 a , 4 b and 4 c or about the licker-in 16 4 as described in connection with FIGS. 3 a , 3 b , 5 a , 5 b and 5 c . For the required shifting of at least the feeding device 10 , 14 in the direction of the arrow K, the feeding device 10 , 14 is mounted on a support block 36 which may be displaced on a base block 37 which, in turn, is stationarily secured to the card frame 38 .
[0024] It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A fiber processing system includes a first roll; a feed tray forming a feeding device with the first roll and defining a clamping location therewith for clamping and advancing fiber material; a second roll cooperating with the feeding device for taking over the fiber material therefrom at a transfer location on the second roll; a third roll cooperating with the second roll for taking over the fiber material from the second roll; and an adjusting arrangement for varying a distance between the clamping and transfer locations. The adjusting arrangement includes a pivoting device for arcuately displacing the second roll about the rotary axis of the first or the third roll; and a shifting device for displacing the feeding device toward or away from the third roll.
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CROSS REFERENCE TO RELATED APPLICATION
This U.S. Patent Application claims the benefit of United Kingdom Patent Application No. 1212191.9 filed Jul. 9, 2012, the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference.
BACKGROUND
There has been a trend in recent years for motor vehicle displays to increase in size and to become more complex functionally. There is, however, a limit to the size and complexity of practical automotive displays incorporating numerous separate display devices, in the same area or in overlapping areas within a single display unit, for example, mechanical dials, gauges and warning lights. Dashboard space is also increasingly at a premium in automobiles.
Rather than increasing the number of components, size, complexity and cost of display units, there is a trend for increasing use of liquid crystal display (LCD) devices in automotive dashboard display units, either by increasing the size of a single LCD device or by using multiple LCD devices. Such LCD devices may, of course, also be used in conjunction with other display devices within the same display unit.
Often, there is a desire to maximize the so-called “dark panel” effect, which is the partial or full concealment of display elements, including back-lit LCD devices, when not in use, so that such display elements or their outlines blend into a surrounding background area within the display unit. To the eye, the concealed display devices and their associated display areas then appear dark, even in bright ambient lighting conditions.
An automotive dashboard display unit will normally have a clear or partially absorbing cover sheet spaced in front of the display devices and display areas of the display unit. If partially absorbing, the cover sheet will be visually clear (i.e. non-scattering) and may either have a neutral color such as grey, or may alternatively be tinted with a color for visual appeal. All such partially absorbing cover sheets, whether of neutral color or tinted, will be referred to herein as “neutral density filters”.
Often the cover sheet will be shielded by a protruding bezel or display surround and be angled so as not to direct stray reflections or bright lights or daylight back towards the eyes of the viewer. The effect of ambient light reflected from the cover sheet is then minimised. However, a significant amount of ambient light will still, of course, be incident on the display areas. Although reflective LCD devices may benefit from such reflected ambient light, this disclosure relates to back-lit LCD devices where ambient light is not used to display information displayed by the LCD device. Such ambient light, when scattered or reflected back towards the viewer from the display unit can reduce the contrast of the displayed information by the back-lit LCD device.
Returned ambient light can also illuminate or emphasize the outer surface of the LCD device itself or the edge or border between the LCD device one or more areas bounding or surrounding the LCD display area, whether or not the LCD is active. Such returned light impairs the dark panel effect.
In such circumstances, one way of improving the dark panel effect is to use a neutral density filter above the display area which reduces the intensity of ambient light incident on the display area and also reduces the intensity of any returned light that is scattered or reflected back towards the viewer. Such a neutral density filter is often incorporated within the outermost cover sheet spaced in front of the display devices and display areas of the display unit. Although the neutral density filter can substantially eliminate returned ambient light such that the dark panel effect is maximized, this is at the cost of reducing the intensity of the transmitted light visible to the user from all light sources within the display unit. It has been found in practice that to achieve a good dark panel effect using such a neutral density filter, it is necessary for the filter to have a transmission of about 37% and to achieve an excellent dark panel effect using such a neutral density filter, it is necessary for the filter to have a transmission of about 26%. To compensate, it becomes necessary to increase the luminance of light sources such as those used to illuminate back-lit LCD devices, with a consequent increase in power consumption and cost for the display unit.
This disclosure provides a display unit having an improved dark panel effect while maintaining an adequate contrast ratio and display brightness in a back-lit LCD device within a display unit.
SUMMARY
The disclosure relates to a display unit, and in particular relates to a display unit for a motor vehicle, having a display area with a back-lit liquid crystal display (LCD) device, and also to such an LCD device bounded on at least one side by a border area.
There is provided a display unit for presenting visible information to a viewer of the display unit, said unit comprising: a back-lit liquid crystal display (LCD) device, said device comprising a display area for displaying said visible information, a light source, and behind said display area a liquid crystal cell, a first polarizer and a second polarizer, said light source being configured to provide back-light illumination to said cell and said polarizers forming a pair of polarizers on opposite sides of said cell such that when said back-light illumination is provided, the first polarizer polarizes said illumination and the second polarizer either passes or blocks said illumination when the polarisation of said illumination is rotated by said cell; a first cover sheet extending over said cell; and a second cover sheet extending over the first cover sheet; wherein one of said first and second cover sheets comprises a third polarizer and the other of said first and second cover sheets comprises a neutral density filter, the third polarizer being aligned with the second polarizer whereby the illumination passed by the second polarizer is passed by the third polarizer, and the first cover sheet is separated from the display area of the LCD device by a gap, and whereby ambient external light incident on the LCD device and reflected or scattered back towards the viewer from said display area is attenuated by two passes through the neutral density filter, and by two passes through the third polarizer sheet.
In some embodiments, the first cover sheet comprises the third polarizer and the second cover sheet comprises the neutral density filter. In alternative embodiments of the invention, the first cover sheet comprises the neutral density filter and the second cover sheet comprises the third polarizer.
Because the third polarizer has the same polarisation properties as that of the second polarizer, the third polarizer does not significantly attenuate the polarized light transmitted from the LCD device. The third polarizer will, however attenuate at least half of the ambient unpolarized light which has been admitted into the display unit towards the display area.
There are a number of advantages to providing the gap between the first cover sheet and the display area, rather than placing the first cover sheet directly on the outer surface or display area of the LCD device. The first is that the LCD device may not have a uniform surface near its edges, as the layers forming the LCD device will need to be bonded together or held together in a frame. Another is that the LCD device will often be bounded by one or more areas on one or more edges of the LCD display area. There may be a step or gap between the LCD display area and such surrounding areas where these border each other. By providing the gap, the first cover sheet can be stretched across any such features or discontinuities, thereby making it possible in principle to provide a smooth outer surface to the display. At the same time, the outer surface of the LCD device is visually concealed from the viewer in returned ambient illumination.
Therefore, when the display unit comprises one or more border areas that lie adjacent to the display area in view of a viewer of the display unit, the first cover sheet preferably extends over such border areas with the first cover sheet being separated from border areas by a gap. This arrangement then helps to visually conceal the outer surface of the, or each, border area, such that ambient external light incident on the LCD device and reflected or scattered back towards the viewer from border area(s) is attenuated by two passes through the neutral density filter, and by two passes through the third polarizer.
Most preferably, the ambient light reflected or scattered back towards the viewer from the display area of the LCD device is substantially the same (e.g. in terms of luminance and/or color spectrum) as the ambient light reflected or scattered back towards the viewer from the border areas. This is so that after attenuation by the first and second cover sheets the, or each, edge of the display is concealed.
In some embodiments, the first cover sheet is joined to the second cover sheet so there is no gap between these sheets.
In other embodiments, the first cover sheet and the second cover sheet are also separated by a gap. In contrast with an arrangement in which the first and second cover sheets have no such gap, for example, by being bonded to each other, this provides the advantage that the first cover sheet and the second cover sheet need not be parallel with each other. Then, when the third polarizer is provided by the first cover sheet, the first cover sheet can be oriented so that this is parallel with the second polarizer, thereby ensuring that the axes of the second polarizer and third polarizer are as closely aligned as possible. At the same time, the second cover sheet, which will include the neutral density filter, can be angled so as to minimise the reflection of ambient light off the outer surface of the second cover sheet directly into the eyes of the viewer.
It will often be the case that border areas near or adjacent the display area are substantially planar, in which case, the first cover sheet is preferably parallel with such border areas.
The display area of the LCD device will also normally be substantially planar, in which case the first cover sheet is preferably parallel with the display area.
In an embodiment, the display area and the border areas are substantially co-planar with each other such that the respective gaps between the border areas and the first cover sheet are substantially the same.
Preferably, the neutral density filter transmits between about 40% and 80% of light incident at a normal angle on the neutral density filter. Most preferably, the neutral density filter transmits between about 50% and 70% of the light incident at a normal angle on the neutral density filter.
In order to achieve a good dark panel effect, it is preferred if the neutral density filter transmits about two-thirds of the light incident on the filter, the ambient light returned to the viewer of the display from the display area being about 0.5% of the total ambient light incident on the second cover sheet. Then, the first and second cover sheets transmit about half of the illumination from the display area out from the second cover sheet.
In order to achieve an excellent dark panel effect, it is preferred if the neutral density filter transmits about half of the light incident on the filter, the ambient light returned to the viewer of the display from the display area being about 0.25% of the total ambient light incident on the second cover sheet. Then, the first and second cover sheets transmit about one-third of the illumination from the display area out from the second cover sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will now be further described, by way of example only, and with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram representing a display unit for presenting visible information to a viewer of the display unit and capable of providing a good dark panel effect, comprising a back-lit liquid crystal cell having first and second polarizers and a neutral density filter (with a 37% pass), separated by a gap from the cell;
FIG. 2 is a schematic diagram showing a display unit for presenting visible information to a viewer of the display unit and capable of providing a good dark panel effect, comprising a back-lit liquid crystal cell having first and second polarizers and a joined neutral density filter (with a 69% pass) and third polarizer that are separated by a gap from the cell;
FIGS. 3 and 4 are schematic diagrams showing a display unit for presenting visible information to a viewer of the display unit and capable of providing a good dark panel effect, comprising a back-lit liquid crystal cell having first and second polarizers and a separated neutral density filter (with a 69% pass) and third polarizer, one of which is separated by a gap from the cell;
FIG. 5 is a schematic diagram representing a display unit for presenting visible information to a viewer of the display unit and capable of providing an excellent dark panel effect, comprising a back-lit liquid crystal cell having first and second polarizers and a neutral density filter (with a 26% pass), separated by a gap from the cell;
FIG. 6 is a schematic diagram showing a display unit for presenting visible information to a viewer of the display unit and capable of providing an excellent dark panel effect, comprising a back-lit liquid crystal cell having first and second polarizers and a joined neutral density filter (with a 50% pass) and third polarizer that are separated by a gap from the cell; and
FIGS. 7 and 8 are schematic diagrams showing a display unit for presenting visible information to a viewer of the display unit and capable of providing an excellent dark panel effect, comprising a back-lit liquid crystal cell having first and second polarizers and a separated neutral density filter (with a 50% pass) and third polarizer, one of which is separated by a gap from the cell.
DETAILED DESCRIPTION
FIGS. 1 and 5 illustrate two embodiments of a display unit for presenting visible information to a person viewing the display unit. The display units comprise a source of visible light (S) for providing back-light illumination (L S ) to a liquid crystal display (LCD) device which comprises a display area (A) for displaying visible information. The light source is therefore behind the display area of a liquid crystal cell, the cell comprising a first polarizer (P 1 ) on the outside of a first glass substrate (G 1 ) nearest the light source and a second polarizer (P 2 ) on the outside of a second glass substrate (G 2 ) directly behind the display area.
Sandwiched between the two glass substrates is a liquid crystal layer (LC) comprising a liquid crystal fluid medium. The liquid crystal cell may be any known type of cell. Not shown are other conventional components of the cell, all of which will be well-known to those skilled in the art, such as, for example, glass bead spacers, and transparent electrodes on the glass substrates for activating and deactivating the liquid crystal medium.
The light source (S) is configured to provide the back-light illumination (L S ), which will usually be unpolarized light, to the cell, passing first into the first polarizer (P 1 ), then the liquid crystal layer (LC) and then the second polarizer (P 2 ). Optionally, the first polarizer may be incorporated into the light source. The polarisation axes of the polarising layers (P 1 , P 2 ) may either be parallel with respect to each other or be crossed, and if crossed will usually be (in the case of linear polarizers) at right angles to each other. If parallel, then the second polarizer will block illumination for which the LCD rotates the polarisation, and if crossed the second polarizer will pass illumination for which the LCD rotates the polarisation. Conversely, if the polarisation axes are parallel, then the second polarizer will pass illumination for which the LCD does not rotate the polarisation, and if crossed the second polarizer will block illumination for which the LCD does not rotate the polarization.
Although the polarizers will most often be linear polarizers, it may alternatively be the case that the polarizers are circular polarizers, either with the same left or right polarisations or with opposite left and right polarizations.
In either case, it is preferred that all polarizers used with the illustrated display units should have no or low birefringence.
The front surface of the display area (A) may be provided by, as drawn, the second polarizer (P 2 ), however, it is also known for the outer layer of the LCD device to be a transparent layer. Similarly, the first polarizer (P 1 ) need not provide the outer layer of the cell nearest the light source if this is provided by a transparent layer.
The display area is bounded by at least one border, which in most cases will be opaque. In the drawings, two border elements or features are illustrated, one of which (B 1 ) stands proud of the surface, and the other of which (B 2 ) is flush or substantially flush with the surface. Such border elements may extend fully around the display area (A), which will often be square or rectangular in outline, or just along some of the sides of the display area.
Each of the display units of FIGS. 1 and 5 is capable of providing a dark panel effect, i.e. the partial or full concealment of display elements, including the back-lit LCD device and any border features, when not in use, so that such display elements or their outlines substantially disappear from view. This is achieved by use of a neutra density filter (ND) spaced in front of the display area (A) and any border features (B 1 , B 2 ) by a gap. The gap (D 1 ) with the display area will normally be greater than or equal to the gap (DB) above any protruding or flush border features (B 1 , B 2 ). The gap may also vary in width if the cover sheet is not parallel with the display area. The neutral density filter is therefore separate from a front surface of the display area (A), and may be provided by an outmost cover for the display unit.
The neutral density filter suppresses the view of the un-active display areas, any border features, and joins or boundaries between the un-active display area and border features, by reducing the amount of ambient light scattered or reflected from these features and directed back towards the person viewing the display unit. In FIG. 1 , the neutral density filter passes 37% of the light entering the filter, and in FIG. 5 , the neutral density filter passes 26% of the light entering the filter.
In all the Figures, the incident ambient light (L A ) in the drawings is shown as being incident at a non-normal angle to the filters and display areas, and this is done only for the sake of clarity so that different reflections can be seen, however in all cases the stated reflection and transmission percentages are those for a normal angle of incidence. Ambient light will, of course, have a range of angles of incidence, however, the stated percentages do illustrate in general terms the performance of the devices described below.
In all the Figures, it has been assumed that the reflectance of light off an external surface will be 4%, although this figure may be somewhat lower if antireflection coatings are provided. In these examples, 4% of incident ambient light (L A ) will be reflected by the neutral density filter, and 96% transmitted into the body of the neutral density filter (ND). In FIG. 1 , 37% of this is transmitted (35.5%) and in FIG. 5 , 26% is transmitted (25%). After 4% reflection off the display area (A) and similar losses due to reflection and transmission in the second pass through the neutral density filter, FIGS. 1 and 5 show that there will be, respectively, 0.5% and 0.25% remaining ambient reflected light (R). Subjectively, these amounts can be classed as a “good” dark panel effect and an “excellent” dark panel effect.
The neutral density filter (ND) also absorbs the transmitted polarized light from the light source, such that of the light exiting the display area visible to the user (L V ) is reduced to, respectively, 35.5% and 25% of the transmitted polarized light exiting the display area (A).
These results are summarized in Table 1 below. Commercially available LCD devices can provide a luminance of typically 200 to 500 cd/m 2 . High luminance displays from about 500 cd/m 2 up to approximately 1000 cd/m 2 are available, but at a relatively high commercial cost for automotive driver display uses. Partly, this additional cost is as a result of having to provide a heat exchange cooler on the light source (S) to keep this within operating temperature bounds. In Table 1, this available but relatively expensive range is indicated by source luminance L S figures that have been underlined.
Luminance displays significantly above 1000 cd/m 2 are not commercially feasible for automotive driver display uses. In Table 1, this limit is indicated by the dashed line in the table and source luminance L S figures shown in bold.
Table 1 shows how much source luminance (L S ) is required to achieve four different levels of luminance visible to the user (L V ), namely: a minimally usable level of visible luminance of 200 cd/m 2 , suitable mainly in dark ambient lighting conditions; an acceptable visible luminance of 350 cd/m 2 , this being the minimum amount suitable for both dark and light ambient lighting conditions; a good visible luminance of 500 cd/m 2 , which is a more preferable amount suitable for both dark and light ambient lighting conditions; and an excellent visible luminance of 650 cd/m 2 , which is the amount suitable even in very bright ambient lighting conditions.
TABLE 1
Luminance required from Source: L S (cd/m 2 )
Good Dark Panel Effect
Excellent Dark Panel Effect
(R≈0.5% returned
(R≈0.25% returned
reflection)
reflection)
Joined
Joined
ND
P &
Separate
ND
P &
Separate
Filter
ND
P & ND
Filter
ND
P & ND
alone
Filters
Filters
alone
Filters
Filters
Luminance
(FIG.
(FIG.
(FIGS. 3 &
(FIG.
(FIG.
(FIGS. 7 &
Visible to
1)
2)
4)
5)
6)
8)
Viewer: L V
Luminance
L V /
L V /
L V /
L V /
L V /
L V /
(cd/m 2 )
Level
35.5%
48.8%
46.8%
25%
35.4%
34.0%
200
Adequate
563
410
427
800
565
588
luminance
required in
dark
ambient
lighting
conditions
350
Acceptable
986
717
748
1400
989
1029
luminance
for all
normal
ambient
lighting
conditions
500
Good
1408
1025
1068
2000
1412
1470
luminance
for all
normal
ambient
lighting
conditions
650
Luminance
1831
1332
1389
2600
1836
1912
required in
extreme
conditions
As can be seen from Table 1, with commercially feasible light sources (S), the neutral density filter (ND) approach is capable of achieving only an acceptable visible luminance for a good dark panel effect of about 0.5% returned ambient light (R) and is only capable of achieving a minimally usable visible luminance for an excellent dark panel effect of about 0.25% returned ambient light (R).
As shown in FIGS. 2-4 and 6 - 8 , the aspects disclosed herein address this limitation by using both a neutral density filter (ND) and an additional, third polarizer (P 3 ), both of which are spaced apart from the display area (A), and optionally also spaced apart from adjacent raised, flush or substantially flush border features (B 1 , B 2 ) by a gap (D 1 , DB). In FIGS. 2-4 and 6 - 8 , components such as the light source (S) and LCD device (P 1 , G 1 , LC, G 2 , P 2 ) are the same as in the devices described above in relation to FIGS. 1 and 5 , and so will not be described again in detail. As in the devices of FIGS. 1 and 5 , the first polarizer (P 1 ) may alternatively be incorporated in the light source (S), and the LCD cell may comprise additional transparent layers, as will be known to those skilled in the art.
The third polarizer (P 3 ) has the same polarisation as the second, or upper polarizer (P 2 ) of the LCD device, so that this third polarizer has a minimum attenuation of display light emitted by the LCD device. The third polarizer will, however, strongly attenuate unpolarized ambient light (L A ). Practical, low cost sheets of linear polarizers will transmit about 73.7% of incident light polarized in the same direction as the polarizer, and will pass about 38.7% of unpolarized light entering the polarizer.
FIGS. 2-4 show embodiments which achieve a good dark panel effect of about 0.5% and FIGS. 6-8 show embodiments which achieve an excellent dark panel effect of about 0.25%.
In FIGS. 2 and 6 , the neutral density filter (ND) and third polarizer (P 3 ) are joined or bonded together and, for a given absorption by the neutral density filter (ND), the same result will be achieved regardless of which of these two elements is closest to the display area (A). The position of these two elements may therefore be interchanged, as indicated by the double headed arrow extending between the neutral density filter (ND) and third polarizer (P 3 ).
FIGS. 3 , 4 , 7 and 8 show arrangements where the neutral density filter (ND) and third polarizer (P 3 ) are separate elements, being separated by a gap (D 2 ). The same optical result is achieved regardless of which of these elements is closest to the display area (A).
With the addition of the third polarizer (P 3 ), FIGS. 2-4 show that, in achieving the same good dark panel effect (R) of about 0.5% as that of the arrangement of FIG. 1 , the neutral density filter (ND) can be made more transmissive, with an increase from 37% to 69%. As a result, the intensity of the visible light (L V ) from the display is increased from 35.5% to 48.8% in the case of FIG. 2 , and to 46.8% in the cases of FIGS. 3 and 4 .
With the addition of the third polarizer (P 3 ), FIGS. 6-8 show that, in achieving the same excellent dark panel effect (R) of about 0.25% as that of the arrangement of FIG. 5 , the neutral density filter (ND) can be made more transmissive, with an increase from 26% to 50%. As a result, the intensity of the visible light (L V ) from the display is increased from 25% to 35.4% in the case of FIG. 6 , and to 34.0% in the cases of FIGS. 7 and 8 .
These results are summarized in Table 1, which show that with commercially feasible light sources (S), the arrangements of FIGS. 2-4 are capable of achieved a good visible luminance for all normal light conditions and with a good dark panel effect of about 0.5% returned ambient light (R), and the arrangements of FIGS. 6-8 are capable of achieved an acceptable visible luminance for light and dark ambient light conditions and with an excellent dark panel effect of about 0.25% returned ambient light (R).
The aspects disclosed herein allow improvement in both user visibility of information displayed by the LCD device and at the same time improved dark panel effect.
The arrangements of FIGS. 3 and 4 provide other potential benefits, owing to the separate provision of the neutral density filter and third polarizer. For optimum performance in terms of blocking reflected ambient light while still passing displayed polarized light, the third polarizer should be as near to parallel to the LCD device as possible. Polarizers also tend to be more expensive that neutral density filters. Both these factors militate towards positioning the third polarizer in proximity with and parallel to the LCD device.
It may, however, be desired to position the neutral density filter at an angle to the plane of the LCD device, so as to direct stray ambient light reflections off the outer and inner surfaces of the neutral density filter away from the eyes of the viewer. The neutral density filter can then be provided in the outermost cover of the display unit and this of course may need to be considerably larger than the dimensions of the inner, third polarizer. The increased size of the neutral density filter as opposed to that of the third polarising filter will not be an issue in terms of cost.
When the display area has a border or frame, then the appearance of this can be minimised if the ambient light reflected or scattered back towards the viewer from the display area of the LCD device is substantially the same (e.g. in terms of luminance and/or color spectrum) as the ambient light reflected or scattered back towards the viewer from the border areas.
The disclosure provides, for a given back-light source, a display unit having a improved dark panel effect while maintaining adequate contrast ratio and display brightness in a back-lit LCD device within the display unit.
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A display unit for a motor vehicle, having a display area with a back-lit liquid crystal display device bounded by a border area is provided. The display unit includes a light source, and behind the display area a liquid crystal cell, a first polarizer and a second polarizer, the light source being configured to provide back-light illumination to the cell and the polarizers forming a pair of polarizers on opposite sides of the cell such that, in use, the first polarizer polarizes the illumination and the second polarizer either passes or blocks this illumination when the polarization of the illumination is rotated by the cell. A first cover sheet extends over said cell, and a second cover sheet extends over the first cover sheet.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/936,156 (referred to as the '156 application” and incorporated herein by reference), titled “STREAMLOADING CONTENT, SUCH AS VIDEO CONTENT FOR EXAMPLE, BY BOTH DOWNLOADING ENHANCEMENT LAYERS OF THE CONTENT AND STREAMING A BASE LAYER OF THE CONTENT,” filed on Jul. 6, 2013 and listing Shivendra Panwar as the inventor, the '156 application claiming benefit to U.S. Provisional Application Ser. No. 61/677,044 titled “STREAMLOADING: A NEW WAY TO STREAM CONTENT TO USERS WITH LIMITED OR EXPENSIVE BANDWIDTH ACCESS,” filed on Jul. 30, 2012, and listing Shivendra Panwar as the inventor (referred to as “the '044 provisional” and incorporated herein by reference). The scope of the present invention is not limited to any requirements of the specific embodiments described in that application.
FEDERAL FUNDING
[0002] This invention was made with Government support and the Government may have certain rights in the invention as provided for by Grants 1230773 and 0905446 by the National Science Foundation.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention concerns playing media content provided from a remote source.
[0005] 2. Background Information
[0006] Modern cellular networks are evolving rapidly. Over the past few years, with the advent of smart mobile devices, a huge increase of data consuming applications, and a manifold increase in the capacity of cellular network bandwidth, users in cellular networks have become extremely data hungry. Cisco predicts cellular data traffic will grow by over eight times in the next four years, with more than two-thirds of it consisting of mobile video. (See, e.g., the article, Cisco, “Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update, 2011-2016,” available at http://goo.gl/reBfY. (February 2012), incorporated herein by reference.) Traffic from next year's video alone is projected to exceed current total mobile traffic. Moreover, video streaming services are expected to constitute a major portion of the mobile video traffic. (See, e.g., the article, J. Erman, A. Gerber, K. K. Ramakrishnan, S. Sen, and O. Spatscheck, Over The Top Video: the Gorilla in Cellular Networks,” Proceedings of the 2011 ACM SIGCOMM conference on Internet Measurement, IMC '11, pages 127-136 (ACM, November 2011), incorporated herein by reference.) Indeed, video traffic has increased to the point that it now constitutes more than half of all Internet traffic. (Recall, e.g., the article, Cisco, “Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update, 2011-2016,” available at http://goo.gl/reBfY. (February 2012), incorporated herein by reference.) Together, a wide range of video delivery services and a surge in the quality of videos account for this phenomenon. As more devices become mobile, demand by users for video delivered to their mobile devices is expected to increase.
[0007] The data rate available to a mobile user in a cellular network often varies. For example, a user located closer to a base station may experience a higher data rate than one who is far away, at the edge of the macrocell. Further, high data rate small cells such as picocells (deployed by the service providers), femtocells, and potentially even WiFi hotspots (deployed by users) are often overlaid on cellular networks. This results in extreme variations in data rates experienced by a mobile user in a cellular network. Yet another source of bandwidth variability are periods and/or areas of congestion in the network (e.g., during peak hours). Note that network congestion is not limited to wireless networks, and is often found in other communications networks (e.g., “wired” communications networks) as well.
[0008] In a video streaming system, the data rate available to a user affects, almost instantaneously, the quality of video experienced by the user. For example, when a user is watching a streaming video, the video quality becomes poor almost as soon as the user moves into a low data rate area. Thus, it will become increasingly important to providing good video streaming services in cellular networks in the near future.
[0009] In recent years, there have been industry proposals to exploit adaptive video streaming in wireless networks. With adaptive video streaming, the video bit rate is switched on-the-fly to provide the best video quality to the user based on the available resources in the network. For example, Microsoft's IIS Smooth Streaming (See, e.g., the reference, A. Zambelli, Mobile Video Transmission Using Scalable Video Coding , (Microsoft Corporation, March 2009), incorporated herein by reference.), Adobe's Flash Dynamic Streaming (See, e.g., the article, D. Hassoun, “Dynamic Streaming in Flash Media Server 3.5—Part 1: Overview of the New Capabilities,” http://goo.gl/0G95h (August 2010), incorporated herein by reference.), and Apple's HTTP Adaptive Bit-rate Streaming (See, e.g., the article, R. Pantos (Ed.) and W. May, “HTTP Live Streaming,” (Apple Inc., September 2012), incorporated herein by reference.) use various techniques to deliver streaming video to users efficiently by dynamically switching among different streams of varying quality and bit-rate to provide a smooth and seamless video to users.
[0010] The research community has also been very active in this area. For example, an intelligent bit-rate switching based adaptive video streaming (ISAVS) algorithm has been proposed. (See, e.g., the article, X. Qiu, H. Liu, D. Li, S. Zhang, D. Ghosal, and B. Mukherjee, “Optimizing HTTP-based Adaptive Video Streaming for Wireless Access Networks, 3 rd IEEE International Conference on Broadband Network and Multimedia Technology ( IC - BNMT ), 2010, pages 838-845 (October 2010), incorporated herein by reference.) The ISAVS algorithm provides the best possible video quality to users with minimum replay interruptions. Similarly, an optimized H.264/AVC-based bit stream switching for mobile video streaming has been proposed. (See, e.g., the article, T. Stockhammer, G. Liebl, and M. Walter, “Optimized H.264/AVC-Based Bit Stream Switching for Mobile Video Streaming,” EURASIP J. Appl. Signal Process ., 2006:127-127 (January 2006), incorporated herein by reference.) The advanced bit stream switching capabilities using SP/SI pictures defined in the H.264/MPEG-4 AVC standard (See, e.g., the article, T. Wiegand, G. Sullivan, G. Bjontegaard, and A. Luthra, “Overview of the H.264/AVC Video Coding Standard,” IEEE Transactions on Circuits and Systems for Video Technology , 13(7):560-576 (July 2003), incorporated herein by reference.) were exploited in the foregoing reference.
[0011] Despite resent proposals such as those referenced above, streaming of content, such as video content, still has certain inherent limitations, some of which are discussed in §1.2.1.4 below. Although playing a previously downloaded video generally avoids such problems, downloads are generally much more costly to users than streams.
[0012] Traditional Video Delivery
[0013] This section discusses traditional video delivery services and introduces their drawbacks when used over modern wireless networks.
[0014] Streaming and Downloading
[0015] There are presently two ways users can legally consume digital media content in the United States—downloads and streaming. A video streaming service is one where the consumer is not allowed to cache more than a short period of video data ahead of the point being watched. (See, e.g., the reference, “Rates and Terms for use of Musical Works under Compulsory License for Making and Distributing of Physical and Digital Phonerecords,” Title 37 Patents, Trademarks, and Copyrights; Chapter III Copyright Royalty Board, Library of Congress; Subchapter E Rates and Terms for Statutory Licenses; Part 385, 37 C.F.R. §385.11 (February 2009), incorporated herein by reference, which pertains to the analogous concept of audio streaming.) More specifically, according to 37 C.F.R. §385.11, “streaming cache reproduction” means a reproduction of a sound recording of a musical work made on a computer or other receiving device by a service solely for the purpose of permitting an end user who has previously received a stream of such sound recording to play such sound recording again from local storage on such computer or other device rather than by means of a transmission; provided that the user is only able to do so while maintaining a live network connection to the service, and such reproduction is encrypted or otherwise protected consistent with prevailing industry standards to prevent it from being played in any other manner or on any device other than the computer or other device on which it was originally made. Services such as Hulu, Netflix, and Amazon Instant Video are examples of video streaming services. On the other hand, a video downloading service is one where the consumer tries to cache as much of the video as their network bandwidth allows, irrespective of the point of video being watched. Examples of video downloading services include iTunes Movie Rentals, Google Play Movies, as well as YouTube. (See, e.g., the article, C. Breen, “Where to Look for Streaming Movies and TV Shows,” http://goo.gl/JlW0I (July 2012), incorporated herein by reference.) Unlike streaming services in which video playback is aborted when a device loses its connection to the network, it may play all the way to the end in a downloading service. Also, unlike a downloading service, seeking back on the video to replay a portion of it requires the data to be sent again in a streaming service.
[0016] Downloads are generally priced much higher than streaming (Recall the definition of “streaming cache reproduction.”) since they confer some ownership rights, as compared with streams, which are consumable only over a limited duration while a “live connection” is maintained. For example, video downloading services are typically ten to a hundred times more expensive than video streaming services, because of the charges imposed by content owners. As a result, from the perspective of price, in most cases, users prefer a streaming service to a downloading service, especially for longer format videos that they are unlikely to view repeatedly.
[0017] On the other hand, streaming, especially for content like video, requires a high bandwidth connection (which may be expensive to the consumer and/or the communications service provider) to be maintained over the duration of its consumption. In some cases, such as in a mobile environment or in any access network that delivers variable bandwidth (e.g., DSL or cable), this bandwidth often cannot be guaranteed for the duration of consumption. Traditionally, the problem of maintaining a high bandwidth connection when streaming video has been addressed by either (a) delivering the streamed content at a relatively low bandwidth, at the cost of reducing the quality and aesthetic enjoyment of the media (e.g., low definition video instead of high definition video), or (ii) by adapting the coding rate, and consequently the quality, in real time to match the bandwidth available. Clearly, the latter option also leads to variable quality.
[0018] The challenge and expense of maintaining a high bandwidth connection is almost always higher in a mobile environment.
[0019] Streaming in Wireless Networks
[0020] With the dramatic increase in the use of mobile devices, more users now intend to watch high quality videos on these devices using wireless network connections such as WiFi or 3G/4G/4G LTE and next generation cellular technologies. These wireless networks inherently provide variable bandwidths to users, especially for those who are mobile. Bandwidths experienced by users in these wireless networks can vary from tens of Mbps to a few Kbps, depending on traffic demand(s) from other user(s), and where the user is located with respect to a base station in case of cellular networks, or with respect to an access point in case of a WiFi hotspot. Since higher quality videos require higher data rates, if the user moves to a low data rate region, or if there is traffic congestion, there will likely be insufficient bandwidth to support the streaming of high definition video. In such scenarios, it is expected that video streaming service providers will prefer to lower the quality of the video delivered, rather than causing an interruption in its playback. As discussed, congestion in any type of communications networks (including “wired” networks) can cause similar challenges.
[0021] Scalable Video Coding
[0022] Lowering the video quality by reducing its bit rate can also be implemented using SVC (i.e., scalable video coding), an extension of the H.264 video coding standard. SVC allows a high quality video to be decomposed into multiple bit streams, with a subset of these bit streams requiring a lower bandwidth that can be used to display a lower quality version of the original video. In other words, a video can be divided into several bit stream layers such that each additional upper layer adds to the quality of the video. Further, every layer consists of predictions based on data decoded by (e.g., typically all of) the layer(s) below it. Thus, every layer directly or indirectly depends on its lower layer(s), and can only be used when (e.g., typically all) layer(s) below it are available to be decoded. The lowest layer, referred to as the “Base Layer” of the video, can be decoded by itself, independent of any other layer. The higher layers of the video that progressively enhance its quality are referred to as “Enhancement Layers” of the video.
[0023] Given its scalability in quality and bit rate of the video, SVC is considered to be a suitable encoding method for mobile TV broadcast/multicast (See, e.g., the article, S. Hua, Y. Guo, Y. Liu, H. Liu, and S. Panwar, “Scalable Video Multicast in Hybrid 3G/Ad-Hoc Networks,” IEEE Transactions on Multimedia , 13(2):402-413 (April 2011), incorporated herein by reference.) as well as video streaming services (See, e.g., the article, T. Schierl, T. Stockhammer, and T. Wiegand, “Mobile Video Transmission Using Scalable Video Coding,” IEEE Transactions on Circuits and Systems for Video Technology , 17(9):1204-1217 (September 2007), incorporated herein by reference.). The video to be streamed is first divided into chunks, where each chunk contains data for a small temporal portion of the video (e.g., on the order of one second of video). In simpler terms, the video can be represented as the sequential playlist of all its temporal chunks (simply referred to as “chunks”, without loss of generality). Each chunk is then divided into a base layer and one or more enhancement layers using SVC. The chunks are then streamed, in sequence, to a user device. At the user device, the chunks are decoded and played, one by one, as they become available. In general, a chunk cannot be played while it is still being downloaded. Under SVC, the user device tries to download as many layers of a chunk of video as the available bandwidth allows, until it is time to start playing the chunk. Using SVC, user devices can avoid interruptions by continuing to play the video at a lower quality when their bandwidth drops, by downloading fewer layers of the chunks of the video.
[0024] Limitations of Streaming
[0025] Although using SVC for streaming videos over wireless networks helps to reduce interruptions to the video as the user experiences varying bandwidths, it still suffers from a few drawbacks when compared to other kinds of video delivery services. For instance, since a user device decoding and playing streaming video cannot (legally) cache (e.g., too many) future chunks of the video (even if they are close to the base station or access point, and have surplus bandwidth available), the quality of video drops as soon as such user devices move away from the base station or access point (and/or as soon as congestion occurs) and their bandwidth falls below the required level to download all layers (that is, the base layer and all enhancement layers) of the video.
[0026] On the other hand, when a use device downloads (as opposed to plays a stream of) a video, the surplus bandwidth available can be used to download future chunks of the video. Thus, with downloading, even when the available bandwidth falls, the user can continue to enjoy the same high quality video since future chunks were stored in cache. Unfortunately, however, as discussed above, downloading video content is generally much more expensive than streaming such content.
[0027] Perceived Needs
[0028] As should be appreciated from the foregoing, although a user may prefer to use a video streaming service from the price perspective, a video downloading service may be preferable from the quality perspective. Consequently, a service that can potentially provide download quality video, while still qualifying legally as a streaming service, is highly desirable for wireless networks.
SUMMARY OF THE INVENTION
[0029] Example embodiments consistent with the present invention provide a video delivery service that, while still (legally) qualifying as a streaming service (Recall, e.g., the reference, “Rates and Terms for use of Musical Works under Compulsory License for Making and Distributing of Physical and Digital Phonerecords,” Title 37 Patents, Trademarks, and Copyrights; Chapter III Copyright Royalty Board, Library of Congress; Subchapter E Rates and Terms for Statutory Licenses; Part 385, 37 C.F.R. §385.11 (February 2009).), offers users video quality potentially as good as those offered by a traditional, more expensive downloading service. Such example embodiments may do so by: (a) requesting, by a client device, enhancement layers of the media content; (b) receiving, by an enhancement layer serving module, the request for enhancement layers of the media content; (c) serving, by the enhancement layer serving module, at least some enhancement layers of the media content to the client device; (d) receiving, by the client device, at least some enhancement layers of the media content; (e) storing, by the client device, the received at least some enhancement layers of the media content; (f) requesting, by the client device, a base layer of the media content; (g) receiving, by a base layer streaming module, the request for a base layer of the media content; (h) streaming, by the base layer streaming module, the base layer of the media content to the client device; (i) receiving, by the client device, the stream of the base layer of the media content; (j) decoding, by the client device, the media content using both (1) the stored at least some enhancement layers of the media content and (2) the received stream of the base layer of the media content; and (k) playing, by the client device, the decoded media content.
[0030] Some example embodiments consistent with the present invention use an extension of the H.264 video coding standard, called Scalable Video Coding (or “SVC”) (See, e.g., the article, H. Schwarz, D. Marpe, and T. Wiegand, “Overview of the Scalable Video Coding Extension of the H.264/AVC Standard,” Circuits and Systems for Video Technology, IEEE Transactions on , 17(9):1103-1120 (September 2007), incorporated herein by reference.), to encode video content into multiple scalable layers, the lowest layer being the base layer, while the higher layer(s) being enhancement layer(s). More specifically, an example streamloading system consistent with the present invention allows users to download enhancement layers, while actually streaming only the base layer of the video. Since the enhancement layers cannot be decoded without the base layer, the example streamloading service (legally) qualifies as a streaming service (the key legal feature of streaming as opposed to downloading being the continuous connection between the server and the user while video content is being viewed. (Recall, e.g., the reference, “Rates and Terms for use of Musical Works under Compulsory License for Making and Distributing of Physical and Digital Phonerecords,” Title 37 Patents, Trademarks, and Copyrights; Chapter III Copyright Royalty Board, Library of Congress; Subchapter E Rates and Terms for Statutory Licenses; Part 385, 37 C.F.R. §385.11 (February 2009).)
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 illustrates an example of data flow in a streamloading system consistent with the present invention.
[0032] FIGS. 2A-2C compare streaming and streamloading when a user device moves from a high data rate center of cell to a low data rate cell edge.
[0033] FIG. 3 includes flow diagrams illustrating example methods consistent with the present invention performed by a user device that can request and decode (and perhaps play) digital content, an enhancement layer server, and a base layer server (which may be the same device as, or a different device from, the enhancement layer server).
[0034] FIG. 4 is a block diagram illustrating an example user client device that can request and decode (and perhaps play) digital content such as layered digital video.
[0035] FIG. 5 is a block diagram illustrating an example server (or an example user client device) that may perform various acts or methods, and store various information (e.g., enhancement layer serving for download, or base layer streaming) generated and/or used by such acts or methods, in a manner consistent with the present invention.
DETAILED DESCRIPTION
[0036] Example embodiments consistent with the present invention may involve novel methods, apparatus, message formats, and/or data structures for encoding, streaming, decoding and/or playing content such as video content. The following description is presented to enable one skilled in the art to make and use the invention, and is provided in the context of particular applications and their requirements. Thus, the following description of embodiments consistent with the present invention provides illustration and description, but is not intended to be exhaustive or to limit the present invention to the precise form disclosed. Various modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles set forth below may be applied to other embodiments and applications. For example, although a series of acts may be described with reference to a flow diagram, the order of acts may differ in other implementations when the performance of one act is not dependent on the completion of another act. Further, non-dependent acts may be performed in parallel. No element, act or instruction used in the description should be construed as critical or essential to the present invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Thus, the present invention is not intended to be limited to the embodiments shown and the inventors regard their invention as any patentable subject matter described.
[0037] In the following, certain terms are defined in §4.1. Then, an overview of an example implementation consistent with the present invention is provided in §4.2. Thereafter, a detailed example implementation consistent with the present invention is described in §4.3. Next, example apparatus consistent with the present invention are described in §4.4. Simulated performance of one example implementation is discussed in §4.5. Alternatives and refinements to some of the example embodiments are described in §4.6. Finally, some conclusions are presented in §4.7.
DEFINITIONS
[0038] As used in this application, a “content streaming service” is one in which a consumer device is not allowed to cache more than a short period (and/or small amount) of content data ahead of the point being played (e.g., watched in the case of a video streaming service). (Recall, e.g., “Rates and Terms for use of Musical Works under Compulsory License for Making and Distributing of Physical and Digital Phonerecords,” Title 37 Patents, Trademarks, and Copyrights; Chapter III Copyright Royalty Board, Library of Congress; Subchapter E Rates and Terms for Statutory Licenses; Part 385, 37 C.F.R. §385.11 (February 2009).) Services such as Hulu, Netflix, and Amazon Instant Video are examples of video streaming services. (Recall, e.g., C. Breen, “Where to Look for Streaming Movies and TV Shows,” http://goo.gl/J1W0I (July 2012).) Content playback is aborted when a device loses its connection to the network in a content streaming service. Unlike a downloading service, seeking back to replay a portion of the content requires the previously played content data to be sent again in a streaming service.
[0039] As used in this application, a “content downloading service” is one in which the consumer device tries to cache as much of the video as their network bandwidth allows, irrespective of the point of video being played (e.g., watched in the case of a video download service). Services such as iTunes Movie Rentals, Google Play Movies, etc., are examples of video downloading services. (Recall, e.g., C. Breen, “Where to Look for Streaming Movies and TV Shows,” http://goo.gl/J1W0I (July 2012).) Once downloaded, a network connection is not needed to play previously downloaded content, and is not needed to perform a seek operation on the content.
[0040] As used in this application, the “base layer” of an encoded media content can be decoded, independent of any higher level layers, to provide a (relatively) low quality version of the media content.
[0041] As used in this application, the “enhancement layer(s)” of an encoded media content cannot be decoded without the corresponding base layer. A given enhancement layer directly or indirectly depends on all of its lower layer(s), and can only be used when all layers below it are available to be decoded. Each higher enhancement layer progressively enhances the quality of the decoded media content.
[0042] As used in this application, a “chunk” is a unit of data that contains information for a small temporal portion of (e.g., video) content to be decoded and/or played (e.g., on the order of one second of video). The entire content can be decoded and/or played by decoding and/or playing a sequence of chunks.
[0043] As used in this application, a “subchunk” is a layer (e.g., a base layer or an enhancement layer) of a chunk.
[0044] As used in this application, a “sliding quality window” is a number of chunks (no greater than the number of chunks of content remaining to be decoded and/or played) immediately following a chunk of the content being played.
[0045] As used in this application, a “legally allowed buffer size” is an amount (measured in terms of time and/or data) of future (not yet played) content permitted, under an applicable law and/or contract or agreement, to be stored.
[0046] Overview
[0047] In some example embodiments consistent with the present invention, the property of SVC (note that SVC is not required), which makes every enhancement layer of a video completely directly or indirectly dependent on all its lower layers, is exploited to provide video delivery that can deliver download quality video, while qualifying as a video streaming service. Recall that any amount of enhancement layer data is of no use if the base layer data for the video is unavailable. More specifically, at least some example embodiments consistent with the present invention allow enhancement layers of any number of future chunks of a video to be delivered in advance (like a downloading service), but restricts the delivery of base layers of chunks to a limited set of chunks just about to be viewed (like a streaming service). Such example embodiments allow user client devices to stream the base layer data of the video and download the enhancement layer data. This combination may be referred to as “video streamloading.” Like a video streaming service, if the network connection is lost, the video playback aborts in a video streamloading service because the streaming of the base layer stops. Similarly, like regular video streaming, with streamloading, seeking back on the video to replay a portion of it requires the base layer data to be streamed again. In addition, any Digital Rights Management (“DRM”) technologies used to protect content in current streaming technologies can also be used with streamloading. This is because of the foregoing properties of a video streamloading service (legally) qualifies it as a video streaming service. Thus, it is expected that content owners would price streamloading services similar to other video streaming services.
[0048] FIG. 1 illustrates operations in a system 100 consistent with the present invention. The system 100 includes a stream server 110 , a download server 120 and a user client device 130 . (Note that although shown separately, functions performed by the stream server 110 and the download server 120 may be performed on a single server.) As shown, the user client device 130 initially fetches future enhancement layer chunks 150 , the downloading of which is only restricted by bandwidth constraints. That is, future enhancement layer chunks are requested as soon as the user client device 130 has spare bandwidth available. The user client device then fetches base layer chunks of video 140 , for example, based on time constraints. That is, a particular base layer chunk 140 is requested only when the user client device 140 is (contractually and/or legally) allowed to request and/or receive the base layer chunks, based on the current play position of the video (or of other content). When playing the video, the user client device assembles the fetched layers of chunks in order 160 , and provides them to the player.
[0049] FIGS. 2A-2C compare streaming and streamloading when a user client device moves from a high data rate center of cell to a low data rate cell edge, such as illustrated in FIG. 2A . In FIGS. 2B and 2C , each a subchunk (i.e., each layer of a chunk) is labeled with t T , which denotes the time slot at which it was downloaded. Assume that chunk of the video takes twelve time slots to play. Referring to FIG. 2B , a streaming system is typically constrained to only download the next few chunks. Consequently, with streaming, under the scenario illustrated in FIG. 2A , the video quality drops as the data rate drops as shown in FIG. 2B . Referring now to FIG. 2C , a streamloading system downloads the enhancement layers of all future video chunks before the data rate drops. Consequently, with streamloading, under the scenario illustrated in FIG. 2A , the user client device can maintain good video quality throughout. More specifically, a user client device in a streamloading system can download all future enhancement layer subchunks before the available bandwidth drops, and can therefore sustain high quality video even when it moves far away from the base station. Thus a video streamloading service has the potential to deliver video quality as good as a video downloading service. In fact, the quality of video in an example streamloading service consistent with the present invention is equivalent to that of a streaming service in the worst case, and is equivalent to a downloading service in the best case.
[0050] As should be appreciated from the forgoing example, when a streamloading user client device is close to the base station (or access point) and surplus bandwidth is available, such surplus bandwidth is exploited to download enhancement layers of future chunks of the video. When the user client device eventually moves away from the base station (or access point, or otherwise loses available bandwidth, for example due to network congestion), if there is a relatively low bandwidth availability, as long as it is sufficient to sustain the streaming of base layer data, it will be possible to play high quality video (because the enhancement layer data for those chunks had been downloaded previously).
[0051] FIG. 3 includes flow diagrams which illustrate example methods 305 / 355 / 375 consistent with the present invention performed by a user client device (Recall, e.g., 130 of FIG. 1 .) that can request and decode (and perhaps play) digital content, an enhancement layer server (Recall, e.g., 120 of FIG. 1 .), and a base layer server (Recall, e.g., 110 of FIG. 1 , which may be the same device as, or a different device from, the enhancement layer server.). Collectively, a system-wide method is provided in which a user client device requests enhancement layers of the media content ( 310 and 315 ). An enhancement layer serving module receives the request for enhancement layers of the media content ( 360 ), and responsive to the received request, serves at least some enhancement layers of the media content to the user client device ( 365 ). The user client device receives the enhancement layer(s) of the media content ( 320 ) and stores the received enhancement layer(s) of the media content ( 325 ). The user client device also requests a base layer of the media content ( 330 and 335 ). A base layer serving module receives the request for a base layer of the media content ( 380 ) and, responsive to the received request, streams the base layer of the media content to the user client device ( 385 ). The client device receives the stream of the base layer of the media content ( 340 ). The user client device may then decode the media content using both (1) the stored enhancement layer(s) of the media content and (2) the received stream of the base layer of the media content. (Block 345 ) The user client device may then play the decoded media content (Block 345 ).
Detailed Example Implementation(s)
[0052] In one example implementation of a streamloading system, a video is to be divided into N sequential chunks, {c i |0≦i<N} each containing an equal length of playing time of the video. Each chunk c i is encoded in M layers, resulting in M subchunks, {s ij |0≦j<M} where s i0 is the base layer subchunk of chunk c i and {s ij |0<j<M} are its enhancement layer subchunks. The user client device starts playing chunk c i as soon as chunk c i-1 finishes playing and subchunk s i0 has finished downloading. A video interruption takes place if subchunk s i0 has not finished downloading by the time chunk c i-1 finishes playing. Once a user client device starts playing chunk c p in any system, only the future subchunks {s ij |p<i<N,0≦j<M} may be downloaded.
[0053] For a user client device playing chunk c p , a video streaming (not streamloading) service only allows subchunks from S p stream to be downloaded, where S p stream ={s ij |p<i<(p+b), 0≦j<M}. In this example, b is the legally and/or contractually allowed buffer size, measured in units of chunks.
[0054] In the example streamloading system, when a user client device is playing chunk c p , only subchunks from S p stream may be downloaded, where:
[0000] S p stream ={s i0 |p<i<+b )}∪{ s ij |p<i<N, 1≦ j<M}.
[0055] S i0 denotes the i th base layer, and S i,j denotes the j th enhancement layer corresponding to the i th base layer. Thus, base layer subchunks are downloaded based on the legally and/or contractually allowed buffer size b, while all future enhancement layer subchunks are allowed to be downloaded.
[0056] As defined in §4.1 above, a sliding quality window consists of w>b chunks immediately following chunk c p being played. It is desirable to continuously optimize the quality of video within the sliding quality window. If S p denotes the set of all downloadable subchunks when chunk c p is playing, in streaming and streamloading systems, subchunk s ij εS p may be downloaded before subchunk s i′j′ εS p when any of the following conditions is true:
[0000] i<i′≦p+w and j=j′;
[0000] i,i′≦p+w and j<j′;
[0000]
i≦p+w<i′;
[0000] p+w<i=i ′ and j<j ′; and
[0000]
p+w<i<i′.
[0057] A time first” chunk serving strategy is a more conservative strategy that favors uninterrupted play over quality. A “quality first” chunk serving strategy is more aggressive strategy that favors quality over uninterrupted play. By manipulating the size of the quality window (to the extent permitted by law and/or contract), a more or less conservative chunk serving strategy can be used. Thus a conservative time first” strategy would download all lower layer enhancement layer sub-chunks in a window, before tackling higher layer subchunks in the window (a left to right policy); this typically implies a larger window because the objective is to download as far into the future as possible. An aggressive “quality first” strategy would download all subchunks over a shorter window (an “down-up” policy); again assuming the two schemes are downloading about the same amount subchunks at any given time. Hybrid policies (e.g., downloading more lower layer enhancement layer subchunks, and less and less higher layer subchunks, thereby providing a “diagonal” policy) are also possible.
[0058] Thus, while chunk c p is playing, at first, all downloadable base layer subchunks are requested for download, earlier subchunks being requested first. Downloadable enhancement layer subchunks falling within the quality window are then requested for download, layer by layer, earlier subchunks being requested first within a layer. After all subchunks belonging to the quality window are downloaded, any remaining downloadable subchunks are then requested for download chunk by chunk, lower layer subchunks being requested first within a chunk.
[0059] In one example implementation, videos are split into chunks and subchunks, with a chunk length of 1.2 s, and coded into four layers (M=4). In this example, N=5000 for a 100 minute video (60*100/1.2). A quality window size w=50 may be used as an example. Naturally, other values are possible and will depend on the application and conditions.
Example Apparatus
[0060] FIG. 4 is a block diagram illustrating an example user client device 400 that can request and decode (and perhaps play) digital content such as layered digital video. Such an example device may include, for example, a desktop computer, a laptop computer, a tablet computer, a smart phone, a set-top box, etc. As shown, the device 400 may include a controller 410 , one or more storage devices 420 , a transmitter 430 , a receiver 440 , a video decoder 450 , a display device 460 and a system bus(es) and/or network(s) 470 . The various components 410 - 460 may communicate with each other via the system bus(es) and/or network(s) 470 . The controller 410 may include a microprocessor, an ASIC, an FPGA, etc., and may control and coordinate operations of the other components 420 - 460 of the device. The storage device(s) 420 may provide volatile and non-volatile storage of information, and/or program instructions. The transmitter 430 may operate transmit various requests. The receiver 440 may operate to receive one or more layers of video information (to be stored, to be decoded, and/or to be viewed, etc.). Video decoder 450 may decode previously downloaded layers and steamed base layers of received video information to be rendered (e.g., on device). The decoded video may then be rendered on a display device 460 . (Audio portions of a video stream may be decoded and rendered on a speaker (not shown).)
[0061] FIG. 5 is a block diagram illustrating an example server (or an example user client device) 500 that may perform various acts or methods, and store various information (e.g., enhancement layer serving for download, or base layer streaming) generated and/or used by such acts or methods, in a manner consistent with the present invention. The apparatus 500 may include one or more processors 510 , one or more input/output interface units 530 , one or more storage devices 520 , and one or more system buses and/or networks 540 for facilitating the communication of information among the coupled elements. One or more input devices 532 and one or more output devices 534 may be coupled with the one or more input/output interfaces 530 . The one or more processors 510 may execute machine-executable instructions to perform one or more aspects of the present invention. At least a portion of the machine executable instructions may be stored (temporarily or more permanently) on the one or more storage devices 520 and/or may be received from an external source via one or more input interface units 530 . In one embodiment, the server may be one or more conventional personal computers. In this case, the processing units 510 may be one or more microprocessors. The bus 540 may include a system bus. The storage devices 520 may include system memory, such as read only memory (ROM) and/or random access memory (RAM). The storage devices 520 may also include a hard disk drive for reading from and writing to a hard disk, a magnetic disk drive for reading from or writing to a (e.g., removable) magnetic disk, an optical disk drive for reading from or writing to a removable (magneto-) optical disk such as a compact disk or other (magneto-) optical media, and solid state storage. A user may enter commands and information into the personal computer through input devices 532 , such as a keyboard and pointing device (e.g., a mouse) for example. Other input devices such as a microphone, a joystick, a game pad, a satellite dish, a scanner, or the like, may also (or alternatively) be included. These and other input devices are often connected to the processing unit(s) 510 through an appropriate interface 530 coupled to the system bus 540 . The output devices 534 may include a monitor or other type of display device, which may also be connected to the system bus 540 via an appropriate interface. In addition to (or instead of) the monitor, the personal computer may include other output devices (not shown), such as speakers and printers for example. The various methods and acts described above (performed either by a server, or even by a user client device) may be performed by one or more of the illustrated apparatus, and the various information described above may be stored on one or more apparatus. Thus, the modeling and design methods described above may be implemented as processor-executable instructions (for example as software modules) stored on a non-transitory storage device (RAM, ROM, magnetic and/or optical disk storage, solid state storage, etc.). These instructions may be executed by one or more processors (for example, microprocessors). Data and/or instructions used may be received by one or more inputs via one or more input interfaces. Data produced may be output by one or more outputs via one or more output interfaces. Therefore, one or more aspects of the methods described above may be implemented on a personal computer, a laptop computer, a tablet, a personal digital assistant, a server, a smart communications device, a set-top box, etc. Alternatively, or in addition, one or more aspects of the methods described above may be implemented on hardware (for example, integrated circuits, application specific integrated circuits, programmable logic or gate arrays, etc.).
[0062] Simulated Performance
[0063] To evaluate the performance of streamloading, the detailed implementation of a video streamloading service described in §4.3 above was simulated by the inventors, and its performance was compared with a streaming service. (See, e.g., the paper, A. Rath, S. Goyal and S. Panwar, “Streamloading: Low Cost High Quality Video Streaming for Mobile Users,” ACM 5 th Workshop on Mobile Video ( MoVid' 13), (Oslo, Norway, 27 Feb. 2013, incorporated herein by reference.) In those simulations, the present inventors found that for all kinds of videos, a streamloading system can serve more than 50% additional users with near perfect video quality, as compared to a streaming system, in the presence of 20 femtocells in the macrocell. Even in the absence of femtocells, a streamloading system can serve as much as 35% additional users with near perfect video quality, as compared to a streaming system. These simulations demonstrated that by using streamloading, network operators can increase their network capacity, and content providers can serve a higher number of users with better quality video using the same network resources. Fluctuations in network capacity might cause fluctuations in video quality that negatively affects user perceived quality, especially as the quality of the video deteriorates. The present inventors found that the fluctuations grow as the quality of the video deteriorates. Since a streamloading system was found to serve better quality videos in almost all scenarios simulated and since it smoothes out the video bit rate as the channel quality varies, the perception, as well as the amount, of fluctuation in quality of video is also generally found to be lower in streamloading.
[0064] Alternatives and Refinements
[0065] The example implementations of a streamloading system described can be modified in a variety of ways. For example, the femtocells used in the simulations discussed in the paper, A. Rath, S. Goyal and S. Panwar, “Streamloading: Low Cost High Quality Video Streaming for Mobile Users,” ACM 5 th Workshop on Mobile Video ( MoVid' 13) could easily be replaced by WiFi hotspots if mobile connectivity for a single connection across these two technologies—cellular and WiFi—can be maintained.
[0066] Scheduling algorithms dictating the order of enhancement layer subchunks to download, can be provided to improve the quality of video experienced and/or to reduce fluctuations in the quality level of the video. For example, transmission scheduling algorithms in the cellular network targeted at streaming video in particular can help reduce the airtime consumed by streamloading users such that download of enhancement subchunks at higher data rate regions is favored by the scheduler to that in lower data rate regions.
[0067] Any encryption or other protection applied to streamed video could be applied to both parts (base layer and enhancement layers) of the video, and the mechanism to delete the video stream after viewing could also proceed in the same manner as in normal streaming. Alternatively, encryption or other protection could be applied to just the base layer, since the base layer is more crucial than the enhancement layers. Since only the base layer is being streamed, the demands on network bandwidth are reduced, thereby reducing the likelihood of a disruption during streaming. This also lowers bandwidth costs to the consumer, or to the service provider in case of flat rate pricing of bandwidth. (Some combination of both is also possible.)
[0068] Other video encoding streams, such as MPEG 4 for example (See, e.g., the article, Marpe, D., Wiegand, T.; Sullivan, G. J., The H.264/MPEG4 advanced video coding standard and its applications,” IEEE Communications Magazine , Volume 44, Issue 8, pp. 134-143 (August 2006), incorporated herein by reference.), have a structure that allow for a similar approach. For example, in the context of MPEG 4, B and P frames can be downloaded (like enhancement layers), and I frames can be streamed (like base layers). Given the dependency of B and P frames on I frames, only a very poor video, of no commercial use, can at best be recovered from B and P frames alone.
[0069] Although the example streamloading systems and methods were discussed in the context of a wireless network, the streamloading methods can also be used in wireline networks such as cable networks (or any Internet service provider (“ISP”), such as satellite TV for example). For example, in one such alternative system, a set top box (or even a computer, or TV) could pre-download enhancement layers, so that a video on demand can be streamed (only the base layer) to the user later using a lower bandwidth. This allows the ISP to reduce bandwidth usage during peak viewing hours, reducing tremendously the expense in capital expenditure for network infrastructure.
[0070] Finally, although the example streamloading systems and methods were described in the context of video content, they can also be modified for use with other media stream coding formats that can be similarly segmented.
CONCLUSIONS
[0071] As can be appreciated from the foregoing, example systems and methods consistent with the present invention enable the provision of low cost streaming video, while reducing the amount of consistent bandwidth needed to consume media content.
[0072] In at least some of the example streamloading implementations, only those parts of the digital representation of the content that add to the quality, but cannot be used, by themselves, to reproduce the content are downloaded. An example of this are the higher layers of SVC (Scalable Video Coding, H.264) video (the enhancement layers) that are useless without the base layer bit stream, and serve to add quality to a video stream beyond that offered by the base layer alone. In an implementation of SVC video using streamloading, the enhancement layers could be downloaded before viewing. This could be done when bandwidth is abundant and/or inexpensive (e.g., in a Wi-Fi hotspot, by an Ethernet connection, or close to a cellular base station, where high bandwidth is available). Later, it would only be the base layer that would be streamed in the traditional manner. Combining the previously downloaded enhancement layers with the incoming base layer stream would lead to a high quality video viewing experience even at bandwidths that support streaming only the base layers.
[0073] Thus, wireless networks with highly variable data rates can provide a streamloading video delivery service that improves the quality of the video watched by mobile users, while still (legally) qualifying as a video streaming service generally offered at cheaper video streaming service prices. The quality of video enjoyed by users in streamloading, in the worst case scenario, is no worse than that in streaming, while in the best case scenario, it can be as good as that in downloading. Since steamloading video delivery can also be used to improve the capacity of a macrocell, it benefits network operators as well as video delivery service providers.
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Video streaming applications are a major contributor to the recent dramatic rise of data traffic in cellular networks. Mobile users in a cellular network often experience fluctuating data rates, which might affect the quality of video they view in a streaming service. Although replacing such video streaming services with video downloading/renting services could potentially allow such mobile users to enjoy consistently higher quality videos, such services typically cost a lot more than video streaming services because of legal copyright pricing and management issues. By downloading enhancement layers but streaming base layers of the content, mobile users can enjoy download-quality videos with a service (legally) classified as a streaming service.
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RELATED APPLICATIONS
[0001] This application is a continuation of Ser. No. 10/368,935, filed Feb. 19, 2003, now pending, which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates the use of certain cannabidiol derivatives and of their dimethyl heptyl homologs (CBD-DMH) in the treatment of nausea and of anti vomiting activity.
BACKGROUND OF THE INVENTION
[0003] It is known that cannabidiol compounds of general formula I
in which R′ stands for CH 3 and R″ stands for
[0004] a. straight or branched alkyl of 5 to 12 carbon atoms;
[0005] b. a group —O—R′″, where R′″ . . . is a straight or branched alkyl of 5 to 9 carbon atoms, or a straight or branched alkyl substituted at the terminal carbon atom by a phenyl group;
[0006] c. a group —(CH 2 ) n —O-alkyl, where n is an integer from 1 to 7 and the alkyl group contains 1 to 5 carbon atoms, are antiiflammatory agents and have analgesic, antianxiety, anticonvulsive, neuroprotective, antipsychotic and anticancer activity.
[0007] There are known many cannabinoid-type compounds which have anti-nausea and anti-vomiting activity. However, many of them are psychoactive which is undesired for this purpose.
SUMMARY OF THE INVENTION
[0008] It has now been found that cannabidiol compounds of general formula I are not psychoactive but are very useful in the treatment of nausea and of anti-vomiting activity.
[0009] The present invention thus consists in the use of cannabidiol compounds of general formula I in the treatment of nausea and of vomiting activity. The compounds are used in particular in the treatment of chemotherapy-induced nausea.
[0010] Thus the invention provides methods for treating nausea and/or vomiting by administering to a subject in need of such treatment a cannabidiol compound as described herein. As used herein, a “subject” shall mean a human, a vertebrate mammal including but not limited to a dog, cat, horse, cow, pig, sheep, goat, or non-human primate, e.g., monkey, or a fowl, e.g., chicken. Included within the scope of the present invention are all animals which are susceptible to nausea and/or vomiting. The term “effective amount” of a cannabidiol compound (optionally combined with other non-cannabidiol compounds) refers to the amount necessary or sufficient to realize a desired biologic effect, e.g., a lessening of nausea and/or vomiting activity.
[0011] The cannabidiol compound of formula II and/or its DMH homolog of formula III may be used as such. It may also be used as part of a pharmaceutical preparation being selected among a tablet, a capsule, a granule, a suspension in a solution, etc.
[0012] Said pharmaceutical preparation may comprise in addition to the active ingredient an excipient selected among a carrier, a disintegrant, a lubricant, a stabilizer, a flavoring agent, a diluent, another pharmaceutically effective compound, etc.
[0013] The diluent may be an aqueous cosolvent solution comprising a pharmaceutically acceptable cosolvent, a micellar solution prepared with natural or synthetic ionic or nonionic surfactants, or a combination of such cosolvent and micellar solutions, etc.
[0014] The carrier may consist essentially of a solution of ethanol, a surfactant or water, or essentially of an emulsion comprising triglycerides, lecitin, glycerol, an emulsifier, an antioxidant, water, etc.
[0015] The present invention will hereinafter be described in detail without being limited by said description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The Figures illustrate the following reactions:
[0017] FIG. 1 . Mean (+sem) frequency of conditioned rejection reactions elicited by a lithium- or saline-paired saccharin solution in Experiment 1 when rats were tested 30 min after an injection of vehicle or cannabidiol (CBD). The groups varied on the basis of the pretreatment drug (CBD or Vehicle) administered 30 min prior to an intraoral infusion of saccharin solution during the conditioning trial and the conditioning drug (Lithium or Saline) administered following saccharin exposure.
[0018] FIG. 2 . Mean (+sem) frequency of conditioned rejection reactions elicited by a lithium- or saline paired saccharin solution in Experiment 2 when the pretreatment and test drug was cannabidiol dimethyllheptyl (CBD-DMH).
[0019] FIG. 3 . Mean (+sem) ml consumed of lithium-paired or saline-paired saccharin solution during a 6 hr consumption test on the day following the final taste reactivity (TR) test trial among rats pretreated with 5 mg/kg of CBD or Vehicle prior to the conditioning trial in Experiment 1.
[0020] FIG. 4 . Mean (+sem) ml consumed of lithium-paired or saline-paired saccharin solution during a 6 hr consumption test on the day following the final TR test trial among rats pretreated with 5 mg/kg of CBD-DMH or Vehicle prior to the conditioning trial in Experiment 2.
DETAILED DESCRIPTION OF THE INVENTION
[0000] 1) Materials and Methods
[0021] a. Experiment 1 uses cannabidiol (CBD) of formula II:
[0022] Experiment 2 uses cannabidiol-dimethyl heptyl (CBD-DMH) of formula III:
In Experiment 1 were used 29 male rats and in Experiment 2 were used 24 male Sprague-Dawley rats (Charles River Labs, St. Constant, Quebec), which weighed 290-350 gm on the conditioning day. They were individually housed in stainless steel hanging cages in a colony room kept at 21° C. on a 12:12 hr light:dark schedule with the lights on at 07.00 h. Throughout the experiment, the rats were maintained on ad-lib Purina Rat Chow and water. The procedures were approved by the Wilfrid Laurier University Animal Care Committee according to the guidelines of the Canadian Council on Animal Care.
[0023] b. The rats were surgically implanted with intra-oral cannulae as described by Parker, L. A. Learn Motiv., 13, 281-303 (1982). The surgical anesthesia preparation included administration of 0.4 mg/kg atropine solution i.p. 15 min prior to ketamine (75 mg/kg, i.p.) combined with xylazine (10 mg/kg, i.p.) which was dissolved in sterile water and administered at a volume of 1 ml/kg. On each of three subsequent days during recovery from surgery, the cannulae were flushed with a chlorhexidine rinse (Novlosan; 0.1% chlorhexidine) to prevent infection.
[0024] c. The design of the experiments evaluated the effect of CBD (Experiment 1) and of CBD-DMH (Experiment 2) on the establishment of conditioned rejection reactions, on the expression of conditioned rejection reactions during testing and the potential role of state dependent learning decrements in responding. The rats were randomly assigned to independent groups on the basis of the pretreatment drug and the conditioning drug. In Experiment 1, the groups were as follows: CBD-lithium (n=8), CBD-saline (n=6), Vehicle-lithium (n=8), Vehicle-saline (n=7). In Experiment 2, the groups were as follows: CBD-DMH—lithium (n=6), CBD-DMH—saline (n=6), Vehicle-lithium (n=6), Vehicle-saline (n=6). All rats were administered two test trials, one following an injection of the drug (Experiment 1: CBD; Experiment 2: CBD-DMH) and the other following an injection of the vehicle. C 6 H 13 The order of the test trials was counterbalanced among the rats in each group.
[0025] d. CBD and CBD-DMH were prepared in a mixture (2.5 mg/ml Vehicle) of 1 ml alcohol/1 ml emulsifier/18 ml saline and were administered at a volume of 2 ml/kg. Lithium chloride was prepared in a 0.15 M (wt/vol) solution with sterile water and was administered at a volume of 20 ml/kg. All injections were intraperitoneally (ip) administered.
[0026] e. One week following the surgery, the rats were adapted to the conditioning procedure. On the adaptation trial, each rat was transported into the room that contained the Plexiglass test chamber (25 cm×25 cm×12 cm ). The room as illuminated by four 25-W light bulbs located 30 cm from either side of the chamber. Each rat was placed individually into the test chamber, and a 30-cm infusion hose was then connected to the cannula through the ceiling of the chamber. A syringe was connected to the hose and placed into the holder for the infusion pump (Model 22; Harvard Apparatus, South Natick, Mass.). After 60 s, the pump delivered water through the tube into the rat's mouth at the rate of 1 ml/min for 2 min. The rat was then returned to its home cage.
[0027] f. The conditioning trial occurred on the following day; it was identical to the adaptation trial, except that the rats were infused with 0.1% saccharin solution rather than water. Thirty min prior to the conditioning trial, the rats were injected ip with either 2 ml/kg of the drug (CBD: Experiment 1; CBD-DMH: Experiment 2) or with the vehicle in which the drug was mixed. Immediately following the infusion of saccharin solution, the rats were injected ip with 20 ml/kg of lithium chloride or saline. During the intraoral infusion, the orofacial and somatic responses displayed by the rats were videotaped from a mirror mounted at a 45° angle beneath the test chamber. Immediately following the TR test, the rat was returned to its home cage.
[0028] g. The Taste Reactivity (TR) test trials were administered 4 and 6 days after the conditioning trial; on the day prior to the first test trial, the rats received an adaptation trial as described above. On each of two test trials, the rats were injected with either 5 mg/kg of the test drug (CBD: Experiment 1; CBD-DMH: Experiment 2) or with the vehicle, thirty min prior to receiving an infusion of saccharin solution for 2 min at the rate of 1 ml/min. The order of the tests was counterbalanced among the rats within each group. The orofacial and somatic reactions displayed by the rats were videotaped during the saccharin exposure.
[0029] h. In both experiments, on the day following the final TR test trial, the rats were administered a consumption test trial in a non-deprived state. On this trial, the water bottles were replaced with tubes containing the saccharin solution and the amounts consumed over a 6 hr period of drinking were recorded.
[0030] i. Taste reactivity scoring: A rater blind to the experimental conditions scored the videotapes on two occasions in slow motion (⅕ speed) using the Observer (Noldus, NL) event-recording program on a PC computer. The frequency of the rejection reactions of gaping (rapid large amplitude opening of the mandible with retraction of the comers of the mouth), chin rubbing (mouth or chin in direct contact with the floor or wall of the chamber and body projected forward) and paw treads (sequential extension of one forelimb against the floor or wall of the chamber while the other forepaw is being retracted) were summated to provide a rejection reaction score (inter-rater reliability: Experiment 1: Vehicle test r (29)=0.91, CBD test r (29)=0.90; Experiment 2: Vehicle test r(24)=0.95; CBD-DMH test r (24)=0.97.
[0000] 2) Results
[0000] a. Taste Reactivity Test:
[0031] FIGS. 1 and 2 present as indicated above the mean frequency of rejection reactions displayed by the rats in the various groups during the vehicle test trial and during the drug (CBD: Experiment 1, CBD-DMH: Experiment 2) test trial. In both experiments, the pattern of responding indicates that the cannabinoid drug interfered with both the establishment of conditioned rejection and with the expression of previously established conditioned rejection reactions.
[0032] In Experiment 1 with CBD, the 2 by 2 by 2 mixed factor ANOVA revealed significant effects of pretreatment drug, F(1, 25)=6.0; p=0.022, conditioning drug, F (1, 25)=10.9; p=0.003, test drug, F (1, 25)=7.4; p=0.012, test drug by conditioning drug, F(1, 25)=6.0; p=0.021 and a pretreatment by conditioning drug interaction that approached statistical significance F(1, 25)=3.6; p=0.069. Subsequent Least Significant Difference (LSD) post-hoc pair-wise comparison tests [20] revealed that the lithium-conditioned rats, but not the saline-conditioned rats, displayed significantly fewer conditioned rejection reactions during the CBD test trial than during the vehicle test trial (p's<0.05). This indicates that CBD attenuated the expression of previously established conditioned rejection reactions. Additionally, across both test drug conditions, the lithium-conditioned rats pretreated with CBD displayed fewer rejection reactions than those pretreated with vehicle (p<0.05) indicating that the CBD pretreatment during conditioning attenuated the establishment of conditioned rejection reactions, presumably by interfering with lithium-induced nausea.
[0033] In Experiment 2, with CBD-DMH, the 2 by 2 by 2 mixed factors ANOVA revealed a significant effect of test drug, F (1, 20)=4.6; p=0.044 and a significant pretreatment drug by conditioning drug by test drug interaction, F (1, 20)=5.6; p=0.028. Subsequent LSD post-hoc pair-wise comparison tests revealed that Group Vehicle-Lithium displayed significantly more rejection reactions during the vehicle test than any other group (p's<0.01) and that this group displayed more rejection reactions during the vehicle test than during the drug test (p<0.01). CBD-DMH interfered with the establishment of conditioned rejection reactions when administered prior to a saccharin-lithium pairing and with the expression of these conditioning rejection reactions when administered prior to the subsequent test of conditioning.
[0034] The attenuation of lithium-induced conditioned rejection reactions during conditioning or testing cannot be interpreted as state-dependent learning decrement, because when rats were trained and tested in the same cannabinoid sate, they displayed fewer rejection reactions than when they were trained and tested in the same vehicle state.
[0000] b. Consumption Test:
[0035] FIGS. 3 and 4 present the mean ml of saccharin solution consumed by the various groups in Experiments 1 and 2 respectively. As is apparent, rats suppressed their consumption of a lithium-paired saccharin solution, but pretreatment with CBD (Experiment 1) or CBD-DMH (Experiment 2) prior to conditioning did not modulate the strength of the avoidance response. A 2 by 2 ANOVA for each Experiment revealed only a significant effect of conditioning drug for Experiment 1 (F(1,22)=25.01; p<0.001) and a marginally significant effect of conditioning drug for Experiment 2 (F(1, 19)=4.36; p=0.051). There were no other significant effects.
[0000] 3) Interpretation
[0036] The non-psychoactive cannabinoids, CBD and CBD-DMH, interfered with the establishment of conditioned rejection reactions (presumably by reducing the lithium-induced nausea) and with the expression of previously established conditioned rejection reactions (presumably by reducing conditioned nausea during the test). These results are the first to describe the anti-nausea properties of the naturally occurring cannabinoid, found in marijuana and its dimethylheptyl homolog. It has previously been reported similar effects produced by the 5HT3 antagonist anti-emetic agent, ondansetron, and THC; that is, both agents interfered with the establishment and the expression of conditioned rejection reactions in rats.
[0037] As has previously been reported using the antiemetic agent, ondansetron, as the pretreatment agent, CBD and CBD-DMH pretreatment did not interfere with the establishment of conditioned taste avoidance in a consumption test. Since treatments without emetic properties elicit taste avoidance, but not conditioned rejection reactions, taste avoidance does not reflect conditioned sickness. On the other hand, only treatments with emetic effects produce conditioned rejection reactions in rats suggesting that this affective change in taste palatability is mediated by nausea.
[0038] The anti-emetic effects of cannabinoid agonists, such as THC and WIN 55-212, appear to be mediated by specific actions at the CB1 receptor, because these effects are blocked by administration of the CB1 receptor antagonist, SR-141716. On the other hand, CBD and CBD-DMH have relatively weak affinity for the CB1 receptor and may be act by preventing the uptake of the endogenous cannabinoid agonist, anandamide. Further research is necessary to determine the specific mechanism by which CBD and CBD-DMH prevent nausea in rats.
CONCLUSION
[0039] The above results demonstrate that the non-psychoactive component of marijuana, cannabidiol, and its synthetic analog, cannabidiol dimethylheptyl, interfere with nausea and with conditioned nausea in rats.
[0040] Therapeutically effective amounts of cannabidiol compounds and homologs can be determined from animal models as described above and as will be well known to and routinely performed by one of ordinary skill in the art. The applied dose can be adjusted based on the relative bioavailability and potency of the administered compound. Adjusting the dose to achieve maximal efficacy based on the methods described above and other methods as are well-known in the art is well within the capabilities of the ordinarily skilled artisan.
[0041] All references that are recited in this application are incorporated in their entirety herein by reference.
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The present invention relates the use of certain cannabidiol derivatives and of their dimethyl heptyl homologs (CBD-DMH) in the treatment of nausea, in particular chemotherapy-induced nausea, and of anti vomiting activity. The present invention relates also to the use of said cannabidiol derivatives being part of a pharmaceutical composition.
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FIELD OF THE INVENTION
The present invention relates to a motor driven shutter used for an automatic exposure camera, and more specifically to a motor driven camera for achieving an automatic exposure by controlling the shutter blades and the diaphragm blades with a single motor.
BACKGROUND OF THE INVENTION
An example of the above-mentioned motor driven shutter is disclosed, for example, in Japanese Published Unexamined Patent Application No. 3-89331. In this shutter, two sets of sectors are used to increase the shutter speed; that is, one set of sectors serves to open the shutter at a high speed, and the other set of sectors serves to set the aperture of the diaphragm and further to close the shutter. In other words, when not released, the first set of sectors are closed for light shading, and the second set of sectors are opened so as to provide a required exposure. When released, the first set of sectors are opened at high speed, and the exposure is attained through the second set of sectors. The exposure is completed when the second set of sectors are closed at a predetermined timing.
In the prior art motor driven shutter, however, since a second sector actuating electromagnet, a first sector actuating electromagnet, and an electromagnet controlling circuit for controlling these magnets are required as the control means, in addition to the stepping motor as the driving control means, the structure thereof is complicated; the structure is large and its cost is high and therefore the structure is subject to increased problems.
SUMMARY OF THE INVENTION
The object of the present invention is to overcome the above-mentioned problems. To achieve the above-mentioned object, the present invention provides a motor driven shutter having a single motor controlled in both forward and reverse rotations, and diaphragm blades and shutter blades controlled by the motor. A driving member is operated by the motor. A diaphragm member sets the diaphragm blades to a predetermined position via the driving member upon forward rotation of the motor. A closing member is engaged at a charge position to operate the diaphragm blades to a closed position. Shutter blades are engaged at a closed position and urged in an open direction. The driving member sets the diaphragm blades to a predetermined position and further releases the shutter blades by releasing the engagement during the reverse rotation of the motor in a diaphragm setting process, and closes the diaphragm blades by releasing the engagement of the closing member during the succeeding operation of the motor.
In the motor driven shutter described above, the motor driven shutter can be driven and controlled by a single motor, so that it is possible to simplify the structure and control operation of the motor driven shutter, and therefore to reduce the size and cost thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, it will now be described in greater detail with reference to the accompanying drawings, wherein:
FIG. 1 is a structural view showing one embodiment of the motor driven shutter according to the present invention;
FIG. 2 is a block diagram showing the control system for controlling the motor driven shutter shown in FIG. 1;
FIG. 3 is a flowchart showing the control sequence of the control system shown in FIG. 2;
FIG. 4 is a flowchart showing a detailed process of the step F12 of the flowchart shown in FIG. 3; and
FIG. 5 is a graphical representation showing the exposure characteristics showing the operational relationship between the diaphragm blades and the shutter blades.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described hereinbelow with reference to the attached drawings. FIGS. 1 to 5 show an embodiment of the motor driven shutter of the present invention. In FIGS. 1 and 2, the symbol HS denotes a home switch for outputting an operation start confirming signal. The home switch HS is a normally closed switch having a movable contact h1 and a fixed contact h2. The movable contact h1 is supported at one end by a pin 6d on a distance ring 6. A spring 6c is disposed between the pin 6d and a base plate 2a. The distance ring 6 is always urged in the clockwise direction by the elastic force of this spring 6c. When a release button SW is not depressed, the distance ring 6 is located at its home position as shown in FIG. 1, in which the home switch HS is held open by the pin 6d. When the release button SW shown in FIG. 2 is depressed, the supply voltage is turned on at the first stroke of the switch button so that a sequence of the automatic focusing operation (lens drive) is executed. Further, at the second stroke of the switch button, an exposure operation and a film winding-up operation are executed.
A pinion 11a fixed to one end of a step motor 4 drives a driving ring to rotate a rachet wheel 7 in the clockwise direction via the driving ring 1 and the distance ring 6 when the step motor 4 is rotated in the reverse direction, so that an engage lever 8 is pushed upward. When an electromagnet 9 is energized at this time, the end portion of the engage lever 8 is held at a position away from the engagement position with the toothed portions of the rachet wheel 7. Thereafter, the step motor 4 rotates in the forward direction in a focusing operation, to transmit rotational motion to the driving ring 1 disposed on the base plate 2 via the pinion 11a fixed to a rotation transmission shaft, so that the distance ring 6 is rotated in the clockwise direction in the drawing via the spring 6c. When the distance ring 6 rotates in the clockwise direction, the movable contact h1 of the opened home switch HS is brought into contact with the fixed contact h2, due to the resulting movement of the pin 6d, to close the home switch HS.
The movable contact h1 of the home switch HS is connected to a reference potential point, and the fixed contact h2 thereof is connected to an input side of a forward and reverse rotation pulse transmitting section 15 of a control circuit CPU, as seen in FIG. 2. The number of pulses transmitted by the forward and reverse rotation pulse transmitting section 15 is determined by a shutter calculating section 17 and a focus adjustment calculating section 18 of the control circuit CPU. When the home switch HS is not closed, the forward and reverse rotation pulse transmitting section 15 cannot transmit a phase pulse to a step motor driving circuit 4a. Further, the forward and reverse rotation pulse transmitting section 15, the shutter calculating section 17, the focus adjustment calculating section 18 and an AF magnet sequence section 16 are all controlled by programs stored in a main control section 19 comprised of a ROM and a RAM. When the AF magnet sequence section 16 is controlled by the main control section 19, the AF magnet sequence section 18 executes a sequential control such that three reverse rotation pulses are transmitted; the electromagnet 9 is operated; and then seven forward rotation pulses are transmitted.
In the camera described above, when the release button SW shown in FIG. 2 is depressed, an operation sequence as shown by a flowchart in FIG. 3 is executed. The depression of the release button SW turns on the supply voltage (in F1), so that the power is held at H (in F2). The distance to the subject is measured by a distance measuring section 18a shown in FIG. 2 (in F3), and the focus adjustment is calculated by the focus adjustment calculating section 18. Three reverse rotation pulses are transmitted from the AF magnet sequence section 16 to the step motor 4 via the forward and reverse rotation pulse transmitting section 15 and the step motor driving circuit 4a (in F4). When three reverse rotation pulses have been transmitted to the step motor 4, the rachet wheel 7 rotates in the clockwise direction and pushes the engagement lever 8 upward. Under these conditions, the AF magnet sequence section 16 outputs a signal to the electromagnet 9 for a retracting operation (in F5). The operation of the electromagnet 9 holds the engagement lever 8 at a position where the end portion of the engage lever 8 is kept away from the engagement position with the tooth portions of the rachet wheel 7. Under control of the AF magnet sequence section 16, seven forward rotation pulses are transmitted from the forward and reverse rotation pulse transmitting section 15 to the step motor 4 to execute the lens drive operation (in F6).
The on or off operation of the home switch HS is detected by this lens driving operation (in F7). When the home switch HS is closed, the forward rotation pulse determined by the focus adjustment calculating section 18 is transmitted to the step motor 4 via the forward and reverse rotation pulse transmitting section 15 (in F8). When an appropriate displacement of the wheel 7 is obtained in the lens driving operation (in F9), the retracting operation of the AF magnet is turned off (in F10). When the release button SW is depressed to the second stroke position, the measuring section 17a measures the brightness of an object to be photographed (in F11), and the shutter calculating section 17 calculates the diaphragm aperture and the shutter speed on the basis of the set contents of a setting section 17b and under various conditions such as the above-mentioned measurement values and the film sensitivity, according to the respective modes of diaphragm priority, shutter speed priority, depth-of-field program, dynamic object program, etc.
Thereafter, an exposure operation is executed (in F12). This exposure operation will be described hereinbelow in further detail with reference to a flowchart shown in FIG. 4. After the engagement lever 8 engages the rachet wheel 7 due to the turn-off operation of the electromagnet 9, when the driving ring 1 is further rotated in the clockwise direction by the step motor 4, the pin 1c is moved away form the distance ring 6, so that a cam portion 1b pushes the pin 5a of the diaphragm lever 5 upward. When the motor 4 rotates through an angular distance corresponding to the number of the pulses applied to the motor, the diaphragm lever 5 is pivoted by the cam portion 1b, so that the opened diaphragm blades 5e are set to a predetermined aperture position by the pin 5b (in Fa) coupled thereto. In more detail, in FIG. 1, the driving ring 1 is rotated to a position slightly further than this predetermined diaphragm aperture position and then the motor 4 is reversed (in Fb), so that an engage stepped portion 1d engages a projection 20c of the set lever 20 to push the set lever 20 against the spring 20b in the upward and leftward direction in the drawing. The set lever 20 is urged in the clockwise direction by the spring 20 to slide in the lower right hand direction. Therefore, the set lever 20 is shifted by the engage stepped portion 1d via the projection 20c, so that the position at which the motor 4 stops corresponds to the set value of the diaphragm (Fc). At this moment, the aperture is fixed at D as shown by the curve A in FIG. 5. When the set lever 20 is shifted against the spring 20b, the roughly L-shaped opening claw 21 is urged by the stepped portion of the set lever 20 to be pivoted in the counterclockwise direction, so that the curved portion 21a shown on the lower and right side in FIG. 1 is released from the stepped portion of the opening ring 10. Therefore, the opening ring 10, previously urged in the clockwise direction by a spring (not shown), is quickly pivoted in the same direction, to quickly open the shutter blades 10a coupled thereto from the closed condition as shown by the curve B in FIG. 5. On the other hand, during the course of shift movement against the spring 20b, the set lever 20 stops the pivotal motion of the closing lever 22 because the projection 20d enters the pivotal range of the curved portion 22c of the closing lever 22, and simultaneously pushes the pin 23a of the closing claw 23 via an opening claw 21 to release the engagement with the curved portion 22c (in Fe).
After the shutter blades 10a have been opened and a required exposure time has been elapsed (in Fg), the motor 4, once stopped, begins to rotate again in the forward direction (in Fh), the set lever 20 is moved by the spring 20c, so that the engagement between the projection 20d and the curved portion 22c is released. When this engagement is released, the closing lever 22 is quickly pivoted in the counterclockwise direction by the spring 22b. Since the projection 22d pushes the pin 5c and pivots the diaphragm lever 5 in the clockwise direction against the spring 5d, the diaphragm blades are closed as shown by the curve A in FIG. 5, so that the exposure ends (Fi). As described above, the camera exposes the film according to the exposure value determined by the aperture D and the exposure time T as shown by the hatched portion in FIG. 5.
The closing lever 22 pivots the set lever 20 at the end of its pivotal motion in the counterclockwise direction by the well-known method (not shown), to move the projection 20c away from the operating range of the engage stepped portion 1d. Thereafter, when the motor 4 rotates in the reverse direction (in F13), although the respective members are returned by the driving ring to the respective home positions as shown in FIG. 1, the opening ring 10 is rotated in the counterclockwise direction against the spring (not shown), to close the shutter blades. After that, the projection 22e is pushed by the pin 10b, and the closing lever 22 is pivoted in the clockwise direction to engage the curved portion 22c with the closing claw 23. Therefore, the diaphragm lever 5 is pivoted by the spring 5d in the counterclockwise direction to open the diaphragm blades again.
After the exposure operation has been executed as described above (in F12), the main control section 19 commands the forward and reverse rotation pulse transmitting section 15 to transmit a reverse rotation pulse to the step motor 4 (in F13). When the motor 4 rotates in the reverse direction, the respective members are returned to the respective home positions by the driving ring 1. Successively, the control discriminates whether the home switch HS is closed or opened. If opened, the film is fed (in F15) and the supply voltage is turned off (in F16). If not closed, in the above step F7, the AF magnet 9 is immediately turned off (in F17), and the reverse rotation pulse is transmitted seven times to restore to the home position (in F18). When the restoration to the home position is not confirmed in step F14 above, the reverse rotation pulse is transmitted again in the steps F19 and F20. A series of the operations of the motor driven shutter ends as described above.
In the above-mentioned embodiment, although the shutter blades are opened via the opening ring 10, it is also possible to realize such a structure that the shutter blades are directly opened without use of the opening ring 10. Further, in the above-mentioned embodiment, the engage lever 8, and the rachet wheel 7 are driven by controlling the electromagnet 9 to hold the distance ring 6 at the predetermined position. Alternatively, without use of these members, it is possible to engage the distance ring 6 at the predetermined position by an engage member; that is, by providing a setting lever (a member having the same function as the set lever 20) engaged with the sector gear 6b and an engage member (e.g. a member having the same function as the closing lever 22) linked with the set lever, and by rotating the motor 4 in the reverse direction during the rotation process of the driving ring 1 in the forward direction for focus adjustment so that the sector gear 6b is moved by the set lever. Further, in the above embodiment, although the shutter blades are opened when the opening ring 10 is released and then pivoted, it is also possible to open the shutter blades 10a by operating the blades to the open and closed positions alternatively with the use of a step motor, for instance.
Further, in the above embodiment, although the diaphragm lever 5 opens the diaphragm blades as shown in FIG. 5, in normal conditions, it is also possible to close the diaphragm blades in the normal condition shown in FIG. 1. In this case, an intermediate member is interposed between the pin 5a and the cam portion 1b. Further, the operation that the closing lever 22 is engaged with the closing claw 23 by the engagement between the pin 10b and the projection 22e can be made at the same time when the motor 4 is rotated in the reverse direction to rotate the rachet wheel 7 and further to move the engage lever 8, not at the end of a series of the operations of the motor driven shutter as the above-mentioned embodiment, but the early stage of the succeeding operation thereof.
Further, in the above-mentioned embodiment, although the operation for closing the shutter blades to complete the exposure is made by rotating the motor 4 in the forward direction again to release the engagement between the curved portion 22c and the projection 20d so that the closing lever 22 is pivoted, it is possible to eliminate the projection 20d and to allow the closing lever 22 to pivot by increasing the shift motion length of the set lever 20 relative to the pin 20a and by rotating the motor 4 additionally in the reverse direction so that the closing claw 23 is released to pivot the closing lever 22. Furthermore, in the above-mentioned embodiment, although a step motor is used as the power source, it is also possible to obtain the same effect by using an ultrasonic motor, a direct current motor having an encoder, etc.
As described above, according to the present invention, the driving ring 1 is operated with the shutter blades 10a closed, the diaphragm blades are then moved to a predetermined position by the diaphragm lever 5 moved by the cam portion 1b; the diaphragm aperture value is set by rotating the motor in the reverse direction; the shutter is opened simultaneously; and then the diaphragm blades are closed by rotating the motor 4. Accordingly, it is possible to perform a series of the diaphragm setting operation and the shutter opening and closing operation by using a single motor as a driving source, thus simplifying the construction and thereby reducing the portions at which trouble may occur. In addition, since only a single power source is used, the control circuit is simple.
Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications depart from the scope of the invention, they should be construed as being included therein.
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A motor driven shutter has diaphragm blades and shutter blades controlled by a single motor. The shutter comprises a driving member actuated by the motor, a diaphragm member for setting the diaphragm blades to a predetermined position via the driving member by the forward rotation of the motor, a closing member for operating the diaphragm blades to a closed position, and shutter blades urged in an open direction. The driving member sets the diaphragm blades to a predetermined position and further releases the shutter blades upon motor rotation in the reverse direction in a diaphragm setting process. The driving member closes the diaphragm blades by releasing the engagement of the closing member in the succeeding operation of the motor.
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BACKGROUND OF THE INVENTION
In drilling for oil, water, or other substances beneath the earth, much use is made of strings of pipe. The pipe, tubing, or the like, may be used to add fluids to, or remove them from the earth. Pipes are also used as a means of transmitting power to a drilling device, e.g., rotary drill. Pipes are also used in certain well repair operations, i.e., well workovers. Usually, a string of pipe is used comprising many individual threaded sections to make up the desired length of pipe or tubing. As pipe goes down the hole, extra sections are threaded on.
In a drilling and/or workover operation, the pipe is usually placed near the well bore to minimize transport and handling of the tubing. The tubing or pipe may be stored vertically, if there is room for storage on the drilling rig. Frequently, such storage is not available, either because of the great amount of pipe involved, or because a relatively small "workover" rig is used to pull tubing, and such small rigs cannot accomodate any significant amount of pipe in vertical storage. In these cases, the pipe is stored horizontally, near the well site.
Typically, a joint of tubing is removed from the well string by unscrewing it from the well string. Usually the threaded or male end, of the pipe is pointing downward, with the top end of the joint of tubing being supported from the top of the derrick. The threads are conventionally protected by metal or plastic caps, with the capped end then being slid along a rack of pipes. Unfortunately, the threaded ends, even when capped, are subject to much wear and consequent deterioration as a result of being slid along a rack of pipes. It would be very beneficial to the industry if a better way of moving the threaded pipe around were available. I studied the problem and found a way to eliminate most of the problems associated with prior art ways of "pulling tubing."
BRIEF SUMMARY OF THE INVENTION
Accordingly, the present invention provides a process for protecting the threaded male end of tubing, pipe, casing, or the like, in drilling and/or workover operations while displacing said tubing, pipe, casing, or the like, from a generally vertical posture in a drill hole to a horizontal placement for storage of same, or from a horizontal placement to a generally vertical posture in order to threadably engage the threaded female end of another tubing, pipe, casing, or the like, prior to entry into the drill hole, said process comprising engaging or suspending the female end of said tubing, pipe, casing, or the like, in order to aid in controlling and directing the same while it is being displaced; situating the threaded male end of said tubing, pipe, casing, or the like, in a male-end transport means including a base, at least one rolling means including a base, at least one rolling means rotatably secured to said base; and transporting said tubing, pipe, casing, or the like, to said desired placement while said female end is engaged or suspended and while said male end is situated in said male-end transport means.
My transport means rides on the top of several lengths of pipe. The transport means may be relatively close to the ground at the start of lay down operations, when riding on a single layer or pipe. After a considerable amount of pipe has been moved to a horizontal posture there will be many layers of pipe or tubing, and the transport means will be higher above the ground.
My device can be used as soon as there is enough tubing available to permit the device to roll upon the tubing. When tubing is being moved to the horizontal posture only two or three lengths of tubing are needed to permit easy horizontal movement of the device. If the surface conditions are adequate, i.e., a storage floor of relatively smooth hard-packed dirt, it may be possible to use the device even from the onset, when no tubing is horizontally stored on the ground. Alternatively, a length of board can be used for the initial horizontal traverses of the device.
My process for protecting the threaded ends of piping is especially important whenever moving internally coated or lined tubing or pipe. This material may be coated or lined to withstand the harsh environments encountered underground, i.e., the presence of salts, acids, hydrogen sulfide, erosive materials, and the like. Any damage to the internal lining may result in significant corrosion or even failure of the tubing, which would make it impossible to retrieve the lower end of the string without an expensive and time-consuming "fishing" job or workover.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an isometric sketch of the present invention showing a transport means useful in practicing the process of the present invention.
FIG. 2 is a side view of the transport means in FIG. 1.
FIG. 3 is a front view of the transport means shown in FIG. 1.
FIG. 4 is a simplified sketch, not to scale, showing the movement of tubing in the transport means at the beginning, middle, and end of a tube transport cycle.
DETAILED DESCRIPTION
FIG. 1 shows an isometric view of the apparatus used in the process of the present invention. Base 1 contains a pair of hard plastic rollers 2 mounted upon axles 10 rotatably mounted within openings 11 on base 1.
Base 1 contains trough 6 defined by two downwardly inclined side surfaces on side walls 12 connected to define a V-shape by end portions 4 and 5. Semi-cirular or curved opening 3, within front wall 4, helps align a joint of tubing within the trough. Back wall 5 is preferably without any recession. The function of wall 5 is to prevent the joint of tubing from slipping out of that end of the V trough. Retention means 7 is a metal strip secured to the bottom of trough 6 in a position intermediate end walls 5 and 4. Retention means 7 will minimize or prevent movement of tubing from end wall 5 to end wall 4, by engaging the cap which may be screwed on the male end of the threaded tubing.
Handle 8 is provided to simplify carrying the tubing pin roller around the job site. Rope loop 9, and handle 8, can be used as anchoring points for ropes or cables to help move the tubing pin roller back and forth.
FIG. 2 is a side view of the device shown in FIG. 1 with a slightly different base configuration. Rollers 22 are mounted on axles 20 fitted within aperatures 31 which are an integral part of base 21. Rope loops 29 are provided at both ends of the tubing pin roller, while handle 28 is only provided at one end. The ends of trough 6 of FIG. 1 are shown in FIG. 2 as end members 24 and 25.
FIG. 3 is a front view of the tubing pin roller shown in FIG. 1. Roller 32 is mounted upon axle 30 which is mounted within base 41. The V-shape of trough 36 is clearly shown in this drawing. Rope loop 39 and handle 38 are shown mounted to base 41.
FIG. 4 shows how the transport means or tubing pin roller is used in practice. Tubing joint 1 is lowered into tubing pin roller 2 which is resting upon layers of horizontally stored tubing 6. The tubing pin roller rolls back to an intermediate horizontal position upon tubing 6, as shown by the location of tubing pin roller 2' containing a joint of tubing 1'. At the end of the horizontal traverse of the layers of pipe 6 the tubing pin roller is shown at the end of the pipe rack as tubing pin roller 2" containing at an almost horizontal position, a joint 1" of tubing.
Initial placement of tubing 1 within tubing pin roller 2 would usually be made manually with a gentle shove or kick given to tubing pin roller 2' to promote horizontal movement of the tubing pin roller as the joint of tubing 1 is slowly lowered to the ground. When the joint of tubing has been lowered to the approximate level of the other tubing 6 already in horizontal storage, the tubing joint would be manually or mechanically lifted from tubing pin roller 2" and set on top of other tubing. A worker could then kick tubing pin roller 2" back for another joint of tubing, or alternatively, a rope may be attached, by means not shown in FIG. 4, and the tubing pin roller pulled back to receive another joint of tubing.
Materials which can be used to make the tubing pin roller are all readily available. I prefer the use of hard plastic rollers on steel rods. Hard plastic rollers two and one-half inches in diameter by 10 inches long work very well over axles of 9/16th inch steel rods. At least two rollers should be used to permit ease of horizontal movement. It would be possible to use even more rollers, e.g., 3, 4 or 5 or even more rollers in parallel, and such construction may be desirable if great load bearing capacity is required or if a low profile for the device is needed.
Alternate means of affixing the rollers to the base may also be used. One acceptable mode of construction would be the use of 5 or 10 roller skate wheels aligned on two parallel axles. The rollers should extend substantially across the entire length of the axle so that the transport means, or tubing pin roller, does not require precise alignment on top of the horizontally stacked pipe to permit free movement.
It is not essential to have end plates or front and back walls 4 and 5 as shown in FIG. 1. The V trough shape 6 will align the pipe to a great extent. In practice, if the axles are kept well lubricated, the rolling coefficient of friction between the tubing pin roller and horizontal tubes is always much less than the static friction between the threaded or capped end of pipe. The tubing, once placed on the tubing pin roller, will remain on the tubing pin roller as it traverses horizontally a rack of pipes, because the force required to move the threaded end of the pipe within the roller is greater than the force required to roll the tubing pin roller.
In practice, the rope loops, such as 9 and 10, are not often needed. If the device is made out of sturdy steel plate, e.g., one-quarter inch thick, the device has sufficient mass to roll horizontally from one end of the pipe rack to the other end with a simple shove. Use of a rope may not be necessary under some conditions. Whenever the outside surface of the pipe, or perhaps the roller surface, deteriorates significantly then the coefficient of rolling friction may increase enough to justify the use of a rope at either or both ends of the tubing pin roller to facilitate horizontal movement of the device.
Instead of trough 6, it may be desirable to provide a horizontal, preferably resilient, surface to engage the threaded end of the pipe. A foam, or solid rubber mat, in a perfectly flat, or V shaped configuration could be used to accomodate the threaded end of a pipe. When a resilient material is used to accomodate the threaded end, it may be possible to dispense with capping of the threaded end of the pipe, though I still prefer to cap the threaded ends of the pipe with a light weight plastic cap to give further insurance against damage to the threaded ends, or any material applied as a liner to the pipe or tubing.
When using a 10 inch roller, an axle length of 10.5 inches works well, the axle can simply be welded to the base, providing a very simple and rugged construction. It is also possible to build the axle into the base before the base is completely fabricated, or provide for the use of timken bearings or the like as a means of affixing the axle to the base. When using two and one-half inch rollers on a 10.5 inch axle, the height of the device, measured from the bottom of the base to the top of end portions 4 or 5 is ideally about 6.75 inches. The length of the end pieces 4 and 5, as measured in a direction parallel to the roller axles, is about 7 inches. The recession 3 provided in end plate 4 is preferably a semi-circle, with a diameter of about 4 inches, though a V shape may be used with good results. The horizontal plates 6 should be inclined to provide a V shape, which will help align the pipe within the tubing pin roller. A V-shape with an included angle of 90°, i.e., a right angle, gives very good results.
The length of the feed trough, as measured on an axis perpendicular to the length of the trough, or distance between end plates 4 and 5 should be about 7 inches. To minimize the amount of horizontal movement of tubing which must occur by hand at the beginning or end of a traverse, it is preferable that one end of the V trough be vertically aligned with one end of the base, as shown in the drawings. This permits the threaded end in the tubing pin roller to approach very closely the other threaded ends in a stack of tubing. There is a very slight loss of stability due to the somewhat lop-sided placement of the V trough, as compared to centering the trough between the axles, but in practice this is not a problem. Actually, this placement of the V trough minimizes problems of the device tilting forward when tubing is placed near the front. With the V trough moved back from the front, the tubing will prevent the tubing pin roller from flipping backwards, while the weight of the tubing pin roller's V trough, and asymmetrical location thereof, minimize the tendency of the device to tip forwards.
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A process for protecting the threaded male end of tubing or the like in a drilling operation when, e.g., tubing is pulled from the ground comprising placing the male end of tubing in a transport means including a base on at least one rolling means and transporting said male end of tubing in the transport means while the female end of the tubing is engaged or suspended in the drilling operation.
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BACKGROUND
[0001] There are robotic cleaning vehicles which traverse the bottom of swimming pools and other large liquid containers submerged in the contained liquid. The robotic cleaning vehicle draws in liquid from ports in their bottom and passing the liquid through filters in the body of the vehicle and expels the filtered liquid back into the large container, typically a swimming pool. These vehicles typically travel on wheels which suspend the body of the vehicle above the bottom of the container. In some cases these wheels are mounted on axles and one of the axles is held at angle other than perpendicular to the general direction of movement of the vehicle so that as the vehicle moves forward and back on its wheels it follows a path that covers a significant portion of the container.
SUMMARY
[0002] A self directed pool cleaning vehicle comprising a body includes a water inlet port and a water outlet port with the inlet port being located on the bottom of the body and containing a filter. A drive mechanism mounted to the body propels the vehicle in two generally opposed directions. A first axle and a second axle, with each axle carrying two wheels at either end, support the body and control its direction of movement in response to the drive mechanism. The axles are mounted to the body such that they can be generally perpendicular to the directions in which the drive mechanism propels the vehicle. The first axle is mounted to the body via a first slot and a second slot, with each slot extending generally in the direction in which the drive mechanism propels the vehicle such that the first axle can move toward either end of the slots. A steering structure is provided having a flexible member with at least a first portion which moves to close a portion of the first slot to limit the movement of the first axle in the first slot, the movement of the first portion changing the angle of the first axle to other than perpendicular to the directions in which the drive mechanism propels the vehicle when the first axle is used as the trailing axle. The steering structure has a locking mechanism which interacts with the body to hold the first portion in a position closing a portion of its slot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a perspective view of a self directed cleaning vehicle which is an embodiment of the present invention with its remote power supply.
[0004] FIG. 2 is a perspective view of the rear axle and associated elements of the vehicle of FIG. 1 .
[0005] FIG. 3 is a side elevation of one of the mounting slots of the rear axle with the steering ribbon unengaged.
[0006] FIG. 4 is a side elevation of one of the mounting slots of the rear axle with the steering ribbon engaged.
[0007] FIG. 5 is a perspective view of the steering ribbon and the wheel well cap that carries an axle mounting slot with the steering ribbon unengaged.
[0008] FIG. 6 is a perspective view of the steering ribbon and the wheel well cap that carries an axle mounting slot with the steering ribbon engaged.
[0009] FIG. 7 is a perspective view of entire the steering ribbon assembly including both axle mounting slots and the locking mechanism.
[0010] FIG. 8 is a perspective view of the bottom of the vehicle of FIG. 1 .
[0011] FIG. 9 is a perspective view of the inside of the vehicle of FIG. 1 with its filters illustrated.
[0012] FIG. 10 is a perspective view of the filter assembly of the vehicle of FIG. 1 .
[0013] FIG. 11 is a perspective view of the mounting of the filter handle to the vehicle.
[0014] FIG. 12 is a perspective view of the inside of the vehicle showing the inlet ports.
[0015] FIG. 13 is a perspective view of one of the filter handles of the vehicle of FIG. 1 .
[0016] FIG. 14 is a perspective view of the filter assembly of the vehicle of FIG. 1 with its hinges shown.
[0017] FIG. 15 is a perspective view of the bottom of the vehicle of FIG. 1 with its passive brushes illustrated.
[0018] FIG. 16 is a cross section along line 16 - 16 of FIG. 6 .
[0019] FIG. 17 is a perspective view of the filter assembly of the vehicle of FIG. 1 partially withdrawn from the vehicle.
[0020] FIG. 18 is a perspective view of a flexible ribbon with slots.
DETAILED DESCRIPTION
[0021] Referring to FIG. 1 a self directed vehicle 10 has a body with a top bridge 11 to which is mounted an electric motor 12 with a shaft 13 projecting out of each end of motor 12 . In an alternative embodiment shaft 13 is two separate shafts, with each separate shaft extending from an opposing end of motor 12 . Attached to each end of the shaft 13 is a propeller 14 which faces an outlet port 15 . Each outlet port is covered with a flap valve 16 hinged to allow the expulsion of water from the vehicle but to prevent its ingress. The electric motor 12 has an external source of power 18 which includes a timing mechanism to reverse the direction of the rotation of the motor 12 . The vehicle 10 also has a chassis or bottom body 20 which is supported by and travels on front wheels 30 and rear wheels 40 . The rear wheels 40 are associated with a steering structure including a steering ribbon or flexible member 50 which is operated by a slide knob 52 . The front wheels 30 are carried by an axle (not shown) which is fixed in its orientation to the chassis 20 .
[0022] The rear wheels 40 are carried by an axle 80 (Shown in FIG.'s 2 , 7 and 16 ) which is able to slide in slots 90 (Shown in FIG.'s 2 - 4 , 6 - 7 and 16 ). A steering ribbon 50 is adjusted to partially block one of these slots from its rear edge. Thus when the axle 80 is the trailing axle (That is the vehicle moving away the ribbon 50 ), one end of the axle 80 cannot move to the rear of its slot and the axle 80 assumes a skewed configuration (Shown in FIG. 16 ).
[0023] FIG. 2 shows details of how the wheel wells 60 of the vehicle carry the wheel well caps 70 which in turn carry the slots 90 in which is mounted the rear axle 80 . It also shows the steering ribbon 50 with its slide knob 52 being guided and supported by the wells 60 and the caps 70 .
[0024] FIG. 3 shows a wheel well cap 70 with its slot 90 unobscured by the steering ribbon 50 while FIG. 4 shows a similar view in which this slot has been obscured by the steering ribbon 50 . FIG. 6 provides another view of a slot 90 being partially obscured by the steering ribbon 50 . The steering ribbon slide knob 52 , by which the position of the steering ribbon can be adjusted, is shown as well as the steering ribbon locking protrusion which interacts with other portions of the vehicle to hold the steering ribbon 50 in a given position. Slide knob 52 may be accessed from outside the body of the vehicle. Below the protrusion 54 is a slit 56 which allows the steering ribbon 50 to flex as the protrusion is moved from one locking position to another. Slit 56 provides a springing effect to locate protrusion 54 within locking slots 102 (Shown in FIG. 7 ). FIG. 5 provides a view similar to that of FIG. 6 in which the steering ribbon 50 is in a non-obscuring position.
[0025] FIG. 7 shows how the steering ribbon 50 interacts with other parts of the vehicle 10 to cause the back axle to become tilted when it is the trailing axle, i.e. when the vehicle is moving in a direction away from the steering ribbon. The right and left ends of the back axle 80 are each mounted in a slot 90 . The right end is free to traverse the length of its slot 90 but the steering ribbon 50 has been positioned to hold the left end at the forward end of its slot 90 . The chassis 20 of the vehicle 10 carries a steering ribbon locking bracket which in turn carries locking slots 102 . These interact with the steering ribbon protrusion 54 shown in FIGS. 5 & 6 to lock the steering ribbon 50 in various positions. In this case the ribbon has been locked in a position such that it occludes most of the left slot 90 . This occlusion can also be seen in FIG. 6 . The slide knob 52 is used to move the steering ribbon 50 between the lock positions established by the steering ribbon locking slots 102 and the steering ribbon slit 56 and the steering ribbon protrusion 54 (Both shown in FIGS. 5 & 6 ) work together to allow the shift between locking positions. The slit 56 allows the protrusion 54 to move downward out of a locking slot 102 as the steering ribbon 50 is moved to the left or right by exerting pressure on the slide knob 52 , which is itself readily accessible from the exterior of the vehicle as can be seen in FIG. 1 . The movement of the steering ribbon 50 is constrained by the ribbon guide track 58 which can be seen in FIG. 16 . The flexible nature of steering ribbon 50 permits at least the end portions of steering ribbon 50 to flex to be maintained within the non linear portions of guide track 58 as the ribbon 50 is moved within the track.
[0026] The vehicle 10 is propelled forward and backwards on its front wheels 30 and back wheels 40 by the operation of the electric motor 12 and its associated propellers 14 expelling water out of one of its outlet ports 15 . The direction of rotation of the electric motor 12 is reversed by its remote power source 18 causing the direction of water expulsion and the direction of travel of the vehicle to be reversed. The power source 18 is conveniently equipped with a timer which causes the reversal and the timer is conveniently set to the time it takes the vehicle to traverse a length or width of the surface being cleaned. Thus as the vehicle reaches an end of this surface, the timer of the power source 18 acts to reverse its general direction of travel. When the steering ribbon 50 is locked in a position such that it occludes a portion of one of the slots 90 , it causes the back axle 80 to become tilted when the vehicle moves forward and this alters the direction of travel of the vehicle. In this way the vehicle traces a pattern that covers the entire surface to be cleaned rather than moving back and forth over the same path.
[0027] Referring to FIG. 8 the bottom of the chassis 20 of the vehicle 10 is provided with inlet ports 22 which have side walls 24 and back walls 26 , as well as flap valves 28 . In one embodiment side walls 24 and back walls 26 extend from the bottom of the chassis 20 in a direction inwardly into the center of the vehicle 10 . In an alternative embodiment, flap valves are attached directly to filter frame 110 . Chassis 20 is provided with drainage slits 23 each of which has a flap valve 25 . In operation the vehicle 10 is submerged beneath the surface of a liquid such as water which covers the surface which the vehicle is to clean such as the floor of a swimming pool. The interior of the vehicle is filled with this liquid as it is submerged. The propellers 14 shown in FIG. 1 then draw fluid in through the inlet ports 22 and expel it out of one of the outlet ports 15 shown in FIG. 1 .
[0028] When the vehicle 10 has completed its cleaning operation it is raised out of the reservoir of liquid covering the surface being cleaned and the liquid contained within the vehicle is permitted to drain out through the drainage slits 23 . The inlet port flap valves 28 allow liquid to be drawn into the interior of the vehicle 10 by the action of the propellers 14 but not to allow it to drain out. On the other hand, the drainage slit flap valves 25 allow the liquid to drain out of the interior of the vehicle 10 when it is raised out of the reservoir but prevents the entrance of the fluid into the interior through the drainage slits 23 when the vehicle is submerged and the propellers 14 are in operation.
[0029] Referring to FIG. 9 each of the inlet ports 22 opens into the interior of a filter frame 110 which is covered by a fine mesh material which serves to filter particulate impurities such as debris and bacteria out of the fluid which passes out of the interior of the filter frame 110 . The inlet port flap valves 28 ensure that when the propellers 14 are not active fluid which has not yet passed through the fine mesh of the filter frame 110 does not drain back out of the vehicle 110 . On the other hand, the drainage slits 23 are positioned outside the filter frame 110 and so only have access to fluid which has passed through the fine mesh of the filter frame 110 .
[0030] The placement of the inlet ports 22 is to accommodate the filter system which in turn is configured to facilitate easy removal of the filter frame 110 . The two inlet ports 22 are each placed on the opposite side of the centerline of the chassis 20 so that each can feed a separate filter frame 110 and yet the two together can cover the entire width of the chassis 20 . The filter frames 110 are configured to be parallel to this center line so that they can be removed without interference with the electric motor 12 and its associated propellers 14 .
[0031] Referring to FIG. 10 the filter system includes filter frame 110 which carries a fine mesh material and has a top 112 , a window 114 and a handle 116 . The window 114 may be transparent which allows the operator of the vehicle 10 to easily see what larger materials have accumulated in the filter frame 110 beneath that window 114 during the cleaning operation of the vehicle 110 .
[0032] The handle 116 provides for the removal of the filter frame 110 for cleaning but also provides a locking function for holding the filter frame 110 in place during the cleaning operation of the vehicle 10 . This locking function is provided by the interaction of the protrusions 122 carried by the filter handle 120 as can be seen in FIG. 12 with the front wall 117 of the filter handle 116 which can be seen in FIG. 13 . The filter handle 116 is constructed as a downward facing u channel with a back wall 119 as well as the front wall 117 . The protrusions 122 fit between these walls in frictional engagement with the front wall 117 to lock the filter frame 110 in place during the cleaning operation of the vehicle 110 . The handle 116 also carries a depression 121 which facilitates grasping the handle 110 and raising it out of a locked position. This depression 121 mates with a depression 124 in the filter trim 120 shown in FIG. 12 to allow easy grasping access to the locked in position filter handle 116 . The handle 116 also carries a shaped boss 118 which mates with a shaped hole 113 in the filter frame top 112 as seen in FIG. 11 such that the upward rotation of the handle is restrained once it reaches the appropriate angle for withdrawal of the filter frame 110 from the chassis 20 . A partial withdrawal at this appropriate angle up and to the side of the centerline of the chassis 20 is shown in FIG. 17 .
[0033] The filter frame 110 is also provided with a door 111 which opens on hinges 115 as can be seen in FIG. 14 . This allows access to the interior of the filter frame 110 for the removal of debris which has accumulated during the cleaning operation of the vehicle 10 . This provides for an easy method for cleaning the filtering system.
[0034] The bottom of the chassis has been provided with passive brushes 130 which can be seen in FIGS. 1 & 15 . As shown each brush extends across the full width of the chassis 20 . However, if the inlet ports 22 were moved closer to the leading and trailing ends of the chassis 20 each passive brush could be shortened such that it just extended across a portion of the width. But in one such embodiment the passive brushes 130 would be mounted such that they jointly covered the entire width of the chassis. Each passive brush 130 is constructed of scrubbing elements which reach to the surface to be cleaned when the chassis 20 is supported on this surface by its front wheels 30 and its rear wheels 40 . In one embodiment the scrubbing elements are stiff bristles.
[0035] In another embodiment, shown in FIG. 18 , steering member or flexible ribbon 50 includes a connecting member 140 that operatively engages axel 80 . In one implementation connecting member 140 includes a first slot 142 and a second slot 144 . Axel 80 extends through first slot 142 and second slot 144 . First slot 142 includes a first end 146 and a second end 148 , the second end 148 being closer to center section 150 than first end 146 . Similarly, second slot 144 includes a first end 152 and a second end 154 , where second end 154 is closer to center section 150 than first end 152 . Note that first slot 142 and second slot 144 have a longitudinal axis defined between first and second ends of each slot. First slot 142 and second slot 144 are in a non linear alignment with center portion 150 . Since ribbon 50 is flexible, the shape of the region of the ribbon adjacent the slots 142 , 144 may vary as ribbon 50 is moved from one position to another position to adjust the axle angle relative to the body as described above.
[0036] In a center setting where knob 52 is positioned midway or equidistant between the wheels 40 attached to axle 80 , axel 80 will be perpendicular to the movement of the vehicle when the vehicle moves in a direction toward slide knob 52 as shown by vector 156 . When the vehicle is moving in the direction of vector 156 axle 80 will be pushed by and adjacent to first ends 146 and 152 of first and second slots 142 and 144 respectively. Similarly, when the vehicle moves rearward in a direction opposite vector 156 , axle 80 remains perpendicular to vector 156 with axle 80 being pushed by and adjacent to second ends 148 and 154 of first and second slots 142 and 144 respectively.
[0037] When a user moves slide knob 52 to a rightward position in vector direction 158 , first end 146 of first slot 142 will pull axle 80 proximate slot 142 in vector direction 156 . However, the portion of axle 80 proximate second slot 144 will be free to travel between first end 152 and second end 154 of second slot 144 . In this configuration, when the vehicle is moving in vector direction 156 , the axel 80 proximate first slot 142 will be in a fixed/restrained mode while the axle 80 proximate second slot 144 will have freedom to move toward the body opposite vector 156 such that axle 80 proximate second slot 144 will be adjacent first end 152 of second slot 144 . As a result, the axle and wheels will be at a non-perpendicular angle relative to vector 156 . This will result in the vehicle being steered or directed in a leftward motion with respect to vector 156 . For purposes of clarity, the vector direction that the vehicle will move in this mode will be between vectors 156 and 158 .
[0038] In this rightward mode when the vehicle is moved in a direction opposite to vector 156 axle 80 proximate first slot 142 will remain fixed relative to first end 146 of first slot 142 while the axle will be pushed to second end 154 of second slot 144 . Hence making the axle perpendicular to vector 156 . As a result the motion of the vehicle in the direction opposite to vector 156 will be straight, while the motion of the vehicle in the general direction of vector 156 will veer in a left ward direction between vectors 156 and 158 as noted above.
[0039] When a user moves slide knob 52 to a leftward position opposite to vector direction 158 , first end 152 of second slot 144 will pull axle 80 proximate slot 144 in vector direction 156 . However, the portion of axle 80 proximate first slot 142 will be free to travel between first end 146 and second end 148 of first slot 142 . In this configuration, when the vehicle is moving in vector direction 156 , the axel 80 proximate second slot 144 will be in a fixed/restrained mode while the axle 80 proximate first slot 142 will have freedom to move toward the body opposite vector 156 such that axle 80 proximate first slot 144 will be adjacent first end 146 of first slot 142 . As a result, the axle and wheels will be at a non-perpendicular angle relative to vector 156 . This will result in the vehicle being steered or directed in a rightward motion with respect to vector 156 . For purposes of clarity, the vector direction that the vehicle will move in this mode will be between vectors 156 and 160 .
[0040] In this leftward mode when the vehicle is moved in a direction opposite to vector 156 axle 80 proximate second slot 144 will remain fixed relative to first end 152 of second slot 144 while the axle 80 proximate first slot 142 will be pushed to second end 148 of first slot 142 . Hence making the axle 80 perpendicular to vector 156 . As a result the motion of the vehicle in the direction opposite to vector 156 will be straight, while the motion of the vehicle in the general direction of vector 156 will veer in a right ward direction between vectors 156 and 160 as noted above.
[0041] While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. It is noted that the construction and arrangement of the pool cleaning vehicle with mechanism for skewing an axle as described herein is illustrative only. Although only a few embodiments of the present invention have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g. variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, elements shown as integrally formed may be constructed of multiple parts or elements and vice versa, the position of elements may be reversed or otherwise varied, and the nature of number of discrete elements or positions may be altered or varied. Additionally, the mechanism for skewing the axle may also be applied to other pool cleaning vehicles including vehicles with wheels driven by a mechanical linkage to a motor, or to vehicles employing a single propeller. Accordingly, all such modifications are intended to be included within the scope of the present invention to be included within the scope of the present invention as defined in the appended claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present inventions as expressed in the appended claims.
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A self directed pool cleaning vehicle comprising a body carrying water inlet and outlet ports with the inlet port being located on the bottom of the body with the body containing a filter is described. A drive mechanism propels the vehicle in two generally opposed directions. Two axles which each carry two wheels support the body and control its direction of movement. One axle is mounted to the body via slots that extend in the directions of motion such that this axle can move toward either end of the slots. A steering structure is provided with a portion that moves to close a portion of one of the slots and can be locked in a position that prevents one end of an axle from traversing its slot. Thus when this axle is the trialing axle it is held at other than a right angle to the two generally opposed directions.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application is a National Stage of International Application No. PCT/KR2007/003783 filed Aug. 7, 2007, and claims the benefit of Korean Patent Application No. 10-2006-0078981 filed on Aug. 21, 2006, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to a data transmission, and more particularly, to a data transmission method and apparatus in a communication environment in which network and/or hardware characteristics are changed.
2. Description of the Related Art
Accompanying the development of communication technology, various kinds of wired/wireless communication services and associated communication standards, which support multimedia communication, exist. In particular, increases in data rates have resulted in an increase of real-time audio and video streaming services through wired/wireless communication. For real-time streaming services, a technique enabling a user to listen to the music or view video in a seamless manner is most important. In particular, when a communication environment is changed, the importance of a data transmission method for seamless communication between a sender and a receiver is emphasized.
FIG. 1 illustrates a case of data communication in which a communication environment is degraded during data transmission.
In FIG. 1 , it is assumed that a mobile terminal of a receiver 11 moves from a Wireless Local Area Network (WLAN) network 130 having a maximum data rate of 2 Mbps to a Wideband Code Division Multiple Access (WCDMA) network 140 having a maximum data rate of 384 Kbps. A sender 12 in a 2 Mbps wireless communication network is transmitting data to the mobile terminal of the receiver 11 at a data rate of 1 Mbps in operation 101 and does not know the characteristics of a network to which the mobile terminal of the receiver 11 moves. Thus, if the sender 12 continuously transmits data to the mobile terminal of the receiver 11 at the same data rate in operation 103 after handover of the mobile terminal of the receiver 11 is accomplished in operation 102 , the mobile terminal of the receiver 11 cannot receive all data transmitted by the sender 12 . That is, a data loss occurs. Thus, if the data being transmitted is streaming data, such as music or video, the receiver 11 cannot seamlessly listen to the music or view the video in real-time.
FIG. 2 illustrates a case of data communication in which a communication environment is improved during data transmission.
In FIG. 2 , it is assumed that a mobile terminal of a receiver 21 moves from a WCDMA network 230 having a maximum data rate of 384 Kbps to a WLAN network 240 having a maximum data rate of 2 Mbps. A sender 22 is transmitting data to the receiver 21 at a data rate of 384 Kbps in operation 201 before handover of the mobile terminal of the receiver 21 and does not know the characteristics of a network to which the mobile terminal of the receiver 21 moves. Thus, if the sender 22 continuously transmits data to the mobile terminal of the receiver 21 at the same data rate in operation 203 after the handover of the mobile terminal of the receiver 21 is accomplished in operation 202 , data transmission is inefficient since the data is transmitted at the data rate of 384 Kbps in the WLAN network 240 having the data rate of maximum 2 Mbps.
Data loss or inefficiency of data transmission may occur in a case of not only the handover between heterogeneous networks illustrated in FIGS. 1 and 2 but also handover between homogeneous networks. In addition, when network characteristics of the same network is changed without a handover, data loss or inefficiency of data transmission may also occur.
Besides the network characteristic information, hardware characteristic information of a sender and/or a receiver may also affect data communication. If the sender continuously transmits data without considering that a mobile terminal of the receiver cannot process data due to a change in an available resource of hardware such as Central Processing Unit (CPU) or memory, the mobile terminal of the receiver cannot receive the data normally.
SUMMARY OF THE INVENTION
Exemplary embodiments of the present invention provides a data transmission method and apparatus for guaranteeing Quality of Service (QoS) of data regardless of a change in a communication environment, which can occur during data transmission. The present invention also provides a computer readable recording medium storing a computer readable program for executing the method.
According to an aspect of the present invention, there is provided a method for transmitting data from a first device to a second device, the method comprising detecting information on a communication environment of the first device; receiving information on a communication environment of the second device from the second device; and adjusting the QoS of the data transmission in an application layer based on at least one of the information on the communication environment of the first device and the information on the communication environment of the second device.
The data may be scalable coded audio or video data.
The adjusting of the QoS may comprise adjusting scalability of the audio or video data based on at least one of the information on the communication environment of the first device and the information on the communication environment of the second device.
According to an aspect of the present invention, there is provided an apparatus for transmitting data of a first device to a second device, the apparatus comprising a characteristic information detector detecting information on a communication environment of the first device; a characteristic information receiver receiving information on a communication environment of the second device from the second device; a determiner determining based on at least one of the information on the communication environment of the first device and the information on the communication environment of the second device, which are provided by the characteristic information receiver, whether adjustment of the QoS of the data transmission is necessary; and a QoS adjuster adjusting the QoS of the data transmission in an application layer according to the determination result of the determiner.
The data may be scalable coded audio or video data.
Scalability of the audio or video data may be adjusted.
According to another aspect of the present invention, there is provided a computer readable recording medium storing a computer readable program for executing the method.
The present invention provides a data transmission method and apparatus for guaranteeing Quality of Service (QoS) of data regardless of a change in a communication environment, which can occur during data transmission. The present invention also provides a computer readable recording medium storing a computer readable program for executing the method.
As described above, according to the present invention, when a sender transmits data to a receiver, the QoS of data transmission can be adjusted by considering communication environments of the sender and the receiver, and thus stable data transmission can be achieved.
The sender can reduce hardware resources required for the data transmission by adjusting scalability of data to be transmitted and a data rate based on information on network and/or hardware characteristics. In addition, the receiver can be guaranteed QoS by receiving the data optimized and transmitted according to the network and/or hardware characteristic information.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and aspects of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 illustrates a case of data communication in which a communication environment is degraded during data transmission;
FIG. 2 illustrates a case of data communication in which a communication environment is improved during data transmission;
FIG. 3A is a flowchart illustrating a data transmission method according to an embodiment of the present invention;
FIG. 3B is a flowchart illustrating a data transmission method according to another embodiment of the present invention; and
FIG. 4 is a block diagram of a data transmission apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3A is a flowchart illustrating a data transmission method according to an embodiment of the present invention.
In FIG. 3A , a first device 31 is a sender transmitting data, and a second device 32 is a receiver receiving the data transmitted by the first device 31 . FIG. 3A illustrates a case where a communication environment of the first device 31 and/or the second device 32 is changed while the first device 31 is transmitting data to the second device 32 . Information on the communication environment includes information on network and/or characteristics of hardware used for the data communication.
The network characteristic information includes information on a kind of network used for the data communication of the first device 31 or the second device 32 and information on a bandwidth available in the network. A change in the network characteristic information may occur when the first device 31 and/or the second device 32 performs a handover to a heterogeneous/homogeneous network.
As illustrated in FIGS. 1 and 2 , if a sender does not know that a receiver performs a handover to a heterogeneous network, a loss of data being transmitted or inefficiency of data transmission may occur. Even when the receiver performs a handover to a homogeneous network, a difference may exist in the number of users or a bit error rate (BER) of a network after handover, resulting in a change in a network characteristic.
The network characteristic may be changed even in the same network without handover, and in this case, an increase or decrease of the number of users and an increase or decrease of BER in the same network are elements which can change the network characteristic.
A change in a hardware characteristic may also affect the data communication between the first device 31 and the second device 32 . The hardware characteristic information includes information on hardware resources available in the first device 31 or the second device 32 , i.e., information on a CPU speed and a memory size. For example, if an available CPU or memory resource of the second device 32 for data reception is decreased due to another task besides the data reception, the second device 32 may not receive data transmitted by the first device 31 .
A case where an available hardware resource of the first device 31 for data transmission is decreased may also affect the data communication. If a specific amount of the data transmitted by the first device 31 must be transmitted to the second device 32 per unit of time, for example, if the data is streaming data, the first device 31 may not transmit the streaming data to the second device 32 in real-time due to a decrease in a CPU or memory resource available for the data transmission.
On the contrary, if an available hardware resource of the first device 31 or the second device 32 is increased, an increase of the QoS of data communication may be necessary. That is, QoS provided to the second device 32 can be increased by reducing the time taken for data transmission by increasing a data rate, or transmitting multimedia data having high image or sound quality.
The network characteristic information and the hardware characteristic information are only illustrations of communication environment information, and all kinds of information affecting QoS of data transmission between the first device 31 and the second device 32 can be included in the communication environment information.
Referring to FIG. 3A , in operation 301 , the first device 31 detects information on its network and/or hardware characteristics.
The network characteristic information includes information on a kind of network and an available bandwidth used by the first device 31 for data communication. The hardware characteristic information includes information on hardware resources available in the first device 31 for the data communication, i.e., information on a CPU speed and a memory size.
The method of extracting the network and/or hardware characteristic information is not limited to a specific method. For example, information on a network characteristic currently used for data transmission can be extracted using a detection method such as Network Driver Interface Specification (NDIS) of Windows Operating System (OS).
In operation 302 , the second device 32 detects information on its network and/or hardware characteristics.
That is, the second device 32 detects information on a network characteristic used to receive data transmitted by the first device 31 and/or information on a hardware characteristic of hardware available for the data reception. As in the case of the first device 31 , a method of extracting the network and/or hardware characteristic information is not limited. For the network characteristic information, a detection method, such as NDIS of Windows OS, can be used.
Although operations 301 and 302 are respectively performed by the first device 31 and the second device 32 , it will be understood by those of ordinary skill in the art that operations 301 and 302 can be performed at the same time or at different times in a different sequence.
In operation 303 , the first device 31 receives the information on the network and/or hardware characteristics of the second device 32 from the second device 32 .
That is, in order for the first device 31 to transmit in consideration of the information on the entire communication environment, the first device 31 receives the information on the network and/or hardware characteristics of the second device 32 .
The network and/or hardware characteristic information can be received using a specifically defined communication protocol or received by expanding an existing communication protocol.
The network and/or hardware characteristic information can be periodically received with a predetermined time interval or received only if the network and/or hardware characteristic information of the second device 32 is changed.
In operation 304 , the first device 31 adjusts the QoS of data transmission based on the network and/or hardware characteristic information of the first device 31 , which has been detected in operation 301 , and the network and/or hardware characteristic information of the second device 32 , which has been received from the second device 32 in operation 303 . The QoS adjustment is performed by an application used to adjust QoS of data transmission.
For example, a data rate is adjusted or data is changed. A change in data occurs when, for example, the scalability of scalable coded audio or video data is adjusted. If the network and/or hardware characteristic information indicates an improved communication environment, data can be transmitted to the second device 32 within a short time by increasing the data rate, or data having high sound or video quality can be transmitted to the second device 32 by adjusting the scalability.
Any method of adjusting QoS of data transmission, such as changing a period of data transmission or a transmission path, can be used in operation 304 .
The adjustment of QoS can be performed only if the network and/or hardware characteristic information of the first device 31 or the second device 32 is changed or performed periodically with a constant time interval. If the network and/or hardware characteristic information of the second device 32 is periodically received in operation 303 , the adjustment of the QoS of data transmission may be periodically performed.
In operation 305 , the first device 31 transmits data to the second device 32 based on the QoS adjusted in operation 304 .
FIG. 3B is a flowchart illustrating a data transmission method according to another embodiment of the present invention.
FIG. 3B illustrates a case where information on a network characteristic includes information on a characteristic that is added or changed in a network path between the first device 31 and the second device 32 .
A network characteristic in a data transmission path also affects data communication between the first device 31 and the second device 32 . This case corresponds to a case where a router or gateway 33 relaying data cannot process a sufficient amount of data. For example, this case corresponds to a case where a network to which the first device 31 and the second device 32 belong to supports a data rate of 100 Mbps while a data rate of the router or gateway 33 does not exceed 10 Mbps. It is assumed that the first device 31 transmits data at a data rate of 10 Mbps regardless of the network environments of the first device 31 and the second device 32 . The router or gateway 33 is only an illustration illustrating how a network characteristic of a transmission path can be affected.
Operations 311 and 312 are the same as operations 301 and 302 illustrated in FIG. 3A . The first device 31 detects information on its network and/or hardware characteristics, and the second device 32 detects information on its network and/or hardware characteristics.
In operation 313 , the second device 32 transmits the detected network and/or hardware characteristic information to the router or gateway 33 .
In operation 314 , the router or gateway 33 adds information on its network characteristic to the network and/or hardware characteristic information received from the second device 32 or changes the network and/or hardware characteristic information received from the second device 32 .
For example, it is assumed that the network characteristic information of the second device 32 is 100 Mbps and the network characteristic information of the router or gateway 33 is 10 Mbps. The router or gateway 33 can change the network characteristic information received from the second device 32 to the network characteristic information of the router or gateway 33 , i.e., 10 Mbps, and transmit the changed network characteristic information to the first device 31 . Alternatively, the router or gateway 33 can add the network characteristic information of the router or gateway 33 to the network characteristic information received from the second device 32 and transmit the added network characteristic information to the first device 31 . In this case, the first device 31 determines a network characteristic affecting data transmission, based on the network characteristic information of the router or gateway 33 and the network characteristic information of the second device 32 .
In operation 315 , the router or gateway 33 transmits the network and/or hardware characteristic information to the first device 31 . Here, the network characteristic information is the information that is added or changed in operation 314 .
Operations 316 and 317 are the same as operations 304 and 305 illustrated in FIG. 3A . The first device 31 adjusts the QoS of data transmission based on the received network and/or hardware characteristic information and transmits data to the second device 32 based on the adjusted QoS.
FIG. 4 is a block diagram of a data transmission apparatus according to an embodiment of the present invention.
In FIG. 4 , the first device 31 is a sender transmitting data, and the second device 32 is a receiver receiving the data transmitted by the first device 31 .
FIG. 4 illustrates a data transmission apparatus of the first device 31 adjusting the QoS of data transmission considering a case where a communication environment of the first device 31 and/or the second device 32 is changed during the data transmission. Information on a network characteristic and information on a hardware characteristic are only illustrations of information on the communication environment, and all kinds of information affecting the QoS of data transmission between the first device 31 and the second device 32 can be included in the communication environment information.
Referring to FIG. 4 , the data transmission apparatus includes a database 41 , a transmitter 42 , and a characteristic information management unit 43 . The characteristic information management unit 43 includes a characteristic information detector 430 , a characteristic information receiver 431 , a determiner 432 , and a QoS adjuster 433 .
The database 41 is a storage unit storing data to be transmitted from the first device 31 to the second device 32 .
The characteristic information detector 430 detects information on network and/or hardware characteristics of the first device 31 . That is, the characteristic information detector 430 detects information on network and/or hardware characteristics, which can be used by the first device 31 for data communication with the second device 32 .
The characteristic information receiver 431 receives information on network and/or hardware characteristics of the second device 32 from the second device 32 . The characteristic information receiver 431 also receives information on a network characteristic that is added or changed by the router or gateway 33 besides the network and/or hardware characteristic information of the second device 32 .
As described above, the network and/or hardware characteristic information may be received as a kind of general data using an existing communication protocol between the first device 31 and the second device 32 without using the specifically defined or expanded communication protocol.
The determiner 432 determines whether adjustment of the QoS of the data transmission is necessary, based on the network and/or hardware characteristic information of the first device 31 , which has been detected by the characteristic information detector 430 , and the network and/or hardware characteristic information of the second device 32 , which has been received by the characteristic information receiver 431 . That is, whether adjustment of the QoS of the data transmission is necessary is determined by determining whether a communication state is degraded or improved.
The QoS adjuster 433 adjusts the QoS of the data transmission by receiving data from the database 41 if the determiner 432 determines that adjustment of the QoS of the data transmission is necessary.
For example, a data rate is adjusted or data is changed. A change in data occurs when, for example, the scalability of scalable coded audio or video data is adjusted. The adjustment of QoS is performed in an application layer using an application for adjusting the QoS of data transmission.
The transmitter 42 transmits the data whose QoS has been adjusted by the QoS adjuster 433 to the second device 32 .
The invention can also be embodied as computer readable codes on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices. In other exemplary embodiments, the computer readable recording medium may include carrier waves (such as data transmission through the Internet). In yet other exemplary embodiments, computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
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Provided is data transmission method and apparatus. A method for transmitting data from a first device to a second device includes detecting information on a communication environment of the first device; receiving information on a communication environment of the second device from the second device; and adjusting the QoS of the data transmission in an application layer based on at least one of the information on the communication environment of the first device and the information on the communication environment of the second device. Accordingly, when a sender transmits data to a receiver, the QoS of data transmission can be adjusted by considering communication environments of the sender and the receiver, and thus optimized data transmission can be achieved.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 10/977,294, filed Oct. 28, 2004 and incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to light emitting diodes (LEDs) and, in particular, to a technique for mounting LED dies for packaging so the packaged LEDs have improved optical, electrical, and thermal characteristics.
BACKGROUND
LEDs are formed by growing epitaxial layers, including p-type and n-type layers, on a growth substrate. A light-emitting active layer is sandwiched between the n and p layers. Green, blue, and ultraviolet LEDs are typically gallium-nitride based, where the growth substrate is typically either sapphire (an insulator), SiC (a semiconductor), silicon, SiC-on-insulator (SiCOI), or other engineered substrate. Infrared, red, and amber LEDs are typically some combination of AlInGaPAs and grown on a GaAs or InP substrate. The growth substrate has a lattice structure similar to the lattice structure of the LED material.
It is sometimes desirable to remove the growth substrate to, for example, improve the optical properties of the LED or to gain electrical access to the LED layers. In the case of a sapphire substrate, removal may be by means of laser melting a GaN/sapphire interface. In the case of Si or GaAs substrates, more conventional selective wet etches may be utilized to remove the substrate.
Since the LED epitaxial layers are extremely thin (e.g., less than 10 microns) and delicate, before removing the growth substrate, the LED wafer must first be attached to a support substrate so that the LED layers are sandwiched between the growth substrate and the support substrate. The support substrate has the desired optical, electrical, and thermal characteristics for a particular application of the LED. The growth substrate is then removed by known processes. The resulting wafer with the support substrate and LED layers is then diced, and the LED dice are then mounted in packages.
A package typically includes a thermally conductive plate with electrical conductors running from the die attach region to the package terminals. The p and n layers of the LED are electrically connected to the package conductors. In the case of a vertical injection device, the support substrate is metal bonded to the package, providing a current path to the n or p-type LED layers adjacent to the support substrate, and the opposite conductivity type layers are connected via a wire (e.g., a wire ribbon) to a package contact pad. In the case of a flip-chip LED (n and p-type layers exposed on the same side), both n and p-connections are formed by die attaching to multiple contact pads patterned to mate to the n and p-contact metallizations on the die. No wires are required.
Some drawbacks with the above-described devices are described below.
The support substrate between the LED layers and the package provides some electrical and thermal resistance, which is undesirable. The support substrate itself adds expense and height. The process of attaching the support substrate to the LED wafer is costly, and yield is lowered.
Accordingly, what is needed is a technique to avoid the above-described drawbacks.
SUMMARY
LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. In one example, the LED is a GaN-based LED, and a relatively thick (approx. 1-2 micron) GaN layer (typically n-type) is grown on the substrate to provide a low-stress transition between the substrate crystal lattice structure and the GaN crystal lattice structure.
The top LED layer (typically p-type) on the wafer is metallized, and the wafer is diced into separate LED elements. For each die, the metallized layer is metal bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and traces leading to solderable package connections.
For each individual chip, the growth substrate is then removed.
The GaN transition layer is then thinned and its top surface textured, patterned, shaped, or roughened to improve light extraction. The thinning reveals (exposes) the n-GaN contact layer, removes the less transparent nucleation layer, and removes crystal damage caused during the growth substrate removal.
If the LED is a vertical injection device, an electrical contact to the thinned GaN layer (usually n-type) is required. A suitable metal contact is formed on the GaN layer, and a wire ribbon or a metal bridge is provided between a contact pad on the package substrate and the contact on the GaN layer. If the LED is a flip chip design, n and p contacts are formed on the side of the LED facing the package substrate and are bonded to contact pads on the package substrate without a wire.
The LED layers are extremely thin (less than 50 microns and typically less than 3 microns) so there is very little absorption of light by the thinned GaN layer; there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween; and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power) is high. The light extraction features (e.g., roughening) of the GaN layer further improves efficiency.
A process is also described where the LED layers are transferred to the package substrate without first being diced. The entire growth substrate is then removed intact so that it may be reused.
The process may be performed on LEDs that are not GaN-based. Other embodiments are described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an LED die, using a sapphire growth substrate, mounted on a package substrate.
FIG. 2 is a cross-sectional view of the sapphire growth substrate being removed using a laser.
FIG. 3 is a cross-sectional view of an LED die, using a silicon based growth substrate, mounted on a package substrate.
FIG. 4 is a cross-sectional view of the silicon-based growth substrate being removed by etching.
FIG. 5 is a cross-sectional view of the LED die of FIG. 2 or 4 being protected by a protective layer.
FIG. 6 is a cross-sectional view of the exposed LED layer being thinned by etching.
FIG. 7 is a cross-sectional view of the LED/protective layer being planarized.
FIG. 8 is a cross-sectional view of the resulting structure after a photomask deposition.
FIG. 9 is a cross-sectional view of the resulting structure after the photomask is selectively exposed and developed to mask selected areas on the top surface of the LED.
FIG. 10 is a cross-sectional view of the resulting structure after a metal deposition.
FIG. 11 is a cross-sectional view of the resulting structure after a metal liftoff process.
FIG. 12 is a cross-sectional view of the exposed portions of the LED layer being roughened for increased light extraction.
FIG. 13A is a cross-sectional view of the resulting structure after the protective layer is removed and after a wire is bonded to the top metal layer.
FIG. 13B is a cross-sectional view of the resulting structure using a metal bridge instead of a wire bond.
FIG. 14 is an alternative to the embodiment of FIG. 1 , where a flip-chip LED is mounted on the package substrate.
FIG. 15 is a cross-sectional view of the flip-chip LED of FIG. 14 after undergoing the applicable process steps illustrated in FIG. 2 (growth substrate removal), FIG. 5 (protective layer formation), FIG. 6 (thinning etch), and FIG. 12 (surface roughening).
FIG. 16 is a cross-sectional view of a flip-chip LED mounted on a package substrate where the metal electrode for the n-layer is distributed across the n-layer in a pattern.
FIG. 17 illustrates one embodiment of the package substrate and LED die mounted and sealed in a housing.
DETAILED DESCRIPTION
A process for providing a very thin LED on a package substrate, without any growth substrate or support substrate, is described with respect to FIGS. 1-16 .
As a preliminary matter, a conventional LED is formed on a growth substrate. In the example used, the LED is a GaN-based LED, such as an AlInGaN LED. The term GaN will be used to represent any GaN-based material. Typically, a relatively thick (approx. 1-2 micron) undoped or n-type GaN layer is grown on a sapphire growth substrate using conventional techniques. Other substrates may also be used, such as SiC, Si, SiCOI, and ZnO. In the case of gallium-phosphide (III-P) LEDs, the growth substrate is typically GaAs or Ge. The relatively thick GaN layer typically includes a low temperature nucleation layer and one or more additional layers so as to provide a low-defect lattice structure for the n-type cladding layer and active layer.
One or more n-type cladding layers are then formed over the thick n-type layer, followed by an active layer, one or more p-type cladding layers, and a p-type contact layer (for metallization).
Various techniques are used to gain electrical access to the n-layers. In a flip-chip example, portions of the p-layers and active layer are etched away to expose an n-layer for metallization. In this way the p contact and n contact are on the same side of the chip and can be directly electrically attached to the package substrate contact pads. Current from the n-metal contact initially flows laterally through the n-layer. In contrast, in a vertical injection (non-flip-chip) LED, an n-contact is formed on one side of the chip, and a p-contact is formed on the other side of the chip. Electrical contact to one of the p or n-contacts is typically made with a wire bond or a metal bridge, and the other contact is directly bonded to a package substrate contact pad.
Examples of forming LEDs are described in U.S. Pat. Nos. 6,649,440 and 6,274,399, both assigned to Lumileds and incorporated by reference.
A wire-bond LED version is described with respect to FIGS. 1-13A .
Flip-chip devices may be extensively tested before dicing. Test parameters include color and brightness. Devices may then be binned (grouped with LEDs having similar attributes).
FIG. 1 is a cross-sectional view of two LED dice 10 mounted on a package substrate 12 . Each LED die 10 includes a sapphire growth substrate 14 , n-type layers 16 , an active layer 18 , and p-type layers 20 . The p-layer surface is highly doped to form an ohmic contact with a die metallization layer (e.g., NiAg). It is preferable if the metallization is highly reflective to light emitted by the active layer. The metallization layer is then bonded to a metal contact pad 22 on the package substrate 12 . The bond technology may be solder, thermocompression, interdiffusion, or a Au stud bump array bonded by an ultrasonic weld. The combination of the die metallization and bond material is shown as metal 24 and may include a diffusion barrier or other layers to protect the optical properties of the metallization layer adjacent the p-layer 20 .
The LED dice 10 are typically from the same wafer but can, instead, be different types and colors.
The package substrate 12 may be an array of package elements that will later be separated. FIG. 1 shows two package elements that will later be separated. Any arrangement of LEDs may be used such as arrays of LEDs or groups of arrays. The package substrate 12 may be formed of the electrically insulating material AlN, with gold contact pads 22 connected to solderable electrodes 26 using vias and/or metal traces. Alternatively, the package substrate 12 may be formed of a conducting material if passivated to prevent shorting, such as anodized AlSiC. In one embodiment, the package substrate 12 is thermally conductive to act as a heat sink or to conduct heat to a larger heat sink. Ultimately the LEDs may have a lens cap attached to them, or be coated with a phosphor (for converting blue or UV light to create a white light), or be further processed, and the package may be soldered to a printed circuit board, if appropriate for the particular application.
FIG. 2 illustrates the growth substrate being removed using an excimer laser beam 30 . The laser beam 30 melts the GaN material at its interface with the growth substrate, allowing the growth substrate to then be lifted off.
FIGS. 3 and 4 illustrate an alternative technique for growth substrate removal using etching. The growth substrate 32 may be silicon based (e.g., SiC, SiC-on-insulator, SiC-on-quartz, Si, etc.) so that it is etchable using conventional etching techniques, such as reactive ion etching (RIE). The etchant is shown as etchant 34 .
Additional non-laser liftoff techniques can be used to remove the growth substrate. Such a liftoff technique may etch away a layer between the growth substrate and the LED layers. For example, the growth substrate may be SiCOI, and an etchant solution etches away the insulator material. The remainder of the growth substrate may then be lifted off. A sapphire substrate with an undercut etch layer may also be used.
The growth substrate 32 may also be removed by lapping. In such a case, the top surface of the package substrate 12 with the dice bonded thereto must be planar. Depositing a filler between the dice may serve to mechanically support the dice during the lapping process.
An unusual aspect of the process described herein is that the LED-forming process is continued after the LED is mounted on the package substrate 12 . In conventional designs, the LED is completely fabricated before being mounted on a support substrate.
A wide array of semiconductor processing may be applied to the transferred LED layers in order to enhance optical extraction and establish electrical contact (for vertical injection devices only). First, however, the package substrate 12 must be protected from the effects of the processing. Note that precise placement (±2 microns) of the dice is typically necessary to allow reliable lithographic process steps.
In FIG. 5 , a protective layer 36 of, for example, polyimide is deposited to protect the package substrate 12 during subsequent processes, such as etching. The protective layer is removed from the top of the LED by a simple planarization step or mask/etch step.
As an alternative to forming the protective layer of FIG. 5 , a thin (<15 micron) layer of UV transparent material (e.g., aluminum oxide) may be deposited over the structure of FIG. 1 prior to the UV excimer laser lift off step. The lifting off the growth substrate ( FIG. 2 ) would then lift off the aluminum oxide only over the growth substrate, providing a self-aligned protective layer for the package substrate 12 . If the thickness of the transparent layer is approximately matched to the LED transferred layers, then planarization of the surface may be achieved.
In FIG. 6 , the exposed, relatively thick, GaN layer 16 is thinned by etching using a dry etch 38 such as RIE. In one example, the thickness of the GaN layer 16 being etched is 7 microns, and the etching reduces the thickness of the GaN layer 16 to approximately 1 micron. If the initial thickness of all the epitaxial LED layers is 9 microns, in this case the etching causes the total thickness of the LED layers to be 3 microns. The thinning process removes any damage caused by the laser lift off process, as well as reduces the thickness of the optically absorbing layers that are no longer needed, such as a low temperature GaN nucleation layer and adjacent layers. All or a portion of the n-type cladding layer adjacent to the active layer is left intact.
For vertical injection type devices, planarization may be required to enable successful lithography. In FIG. 7 , the structure is planarized in preparation for a metallization step. Planarization and top metallization is not needed if the LED is a flip-chip type, discussed with respect to FIGS. 14 and 15 . Planarization may be performed with a simple mechanical polishing step.
In FIG. 8 , a photoresist 40 is deposited.
In FIG. 9 , the photoresist is selectively exposed by UV radiation through a mask and developed to leave mask portions 42 , where it is desired to contact the exposed n-layer 16 with metal. The subsequent metal layer may form fingers or another pattern to distribute the current while providing space for light to pass. Alternatively, the metal layer can be made very thin so as to be transparent. Alternatively, a transparent conductor such as indium tin oxide (ITO) may be employed to spread current.
In FIG. 10 , a metal 44 is deposited. The metal may be any conventional metal used in LEDs, such as Au, Ni, Ag, and combinations of metals for forming metal alloys. The metal may be deposited by sputtering or evaporation.
In FIG. 11 , a metal liftoff process is performed by dissolving the underlying photoresist and lifting off the metal. As an alternative to FIGS. 8-10 , the metal layer(s) may be deposited first, and lithographic patterning of the metals can be achieved with metal etching using a photoresist mask.
In FIG. 12 , the light-emitting top surface of the LED (n-layer 16 ) is roughened for increased light extraction. In one embodiment, layer 16 is photo-electrochemically etched using a KOH solution 46 . This forms a “white” roughness in the GaN surface (having n-type Si doping). This etching process can be used to further thin the n-layer 16 and stop at a predetermined thickness using an etch stop layer grown during the LED formation process. This latter approach is useful for resonant device designs. For such devices, a mirror stack (e.g., a Bragg reflector) may now be deposited on the top surface of the LED. Additional light extraction techniques could include micron or nanometer scale patterned etching (dimple or photonic crystal). Forming patterns such a dimples or photonic crystals are well known.
The protective layer 36 is then chemically removed.
If desired, a phosphor material may be deposited over the LED die for wavelength shifting the light. The phosphor may be deposited using an electro-phoretic deposition (EPD) or screen-printing technique.
In FIG. 13A , a wire 48 is bonded to the top metal 44 and a package substrate contact pad 22 . Alternatively, a rigid metal bridge 47 , shown in FIG. 13B , may be deposited between the metal 44 and the pad 22 .
The resulting package substrate 12 is then diced using conventional techniques (e.g., scribe-and-break or sawing). Each package substrate die may contain one or more LEDs, either of the same color or of different colors. Each package substrate die may contain other circuitry, such as detectors, multiplexers, regulators, etc. The resulting package element may be further processed by, for example, receiving an LED lens cap, mounting on a printed circuit board, etc.
The resulting package element of FIG. 13A or 13 B has a very thin LED directly mounted on a package substrate that extends beyond the boundaries of the LED. No support substrate is required, thus eliminating the thermal and electrical resistance introduced by a support substrate. Since the LED is very thin, there is little optical absorption by the layers. Light extraction features may be provided in the top layer surface. In the case of roughening the surface, high surface randomization is provided, and photons generated within the epitaxial layers experience a high frequency of randomizing events. The short path length between events and the absence of absorbing regions of epitaxial material (e.g., the absence of a low-temperature GaN nucleation layer and adjacent high defect density regions) ensure a high light extraction efficiency.
The resulting thin film (TF) LEDs are also advantageous for resonant structures such as resonant cavity and photonic-crystal based LEDs, since the reduced thickness of high refractive index material substantially reduces the number of optical modes and allows for designs with higher extraction efficiency and radiance.
In one embodiment, the distance between the primary emission surface (the top surface) and the package substrate surface is less than 50 microns, although typically the distance will be much less (e.g., 20 microns or less). The thickness of the LED layers may be 10 microns or less and typically less than 3 microns.
FIGS. 14 and 15 illustrate the use of a flip-chip LED 49 in the above described packaging method. A flip-chip LED does not require any wire bond for contacting the n or p-layers so that it has a lower profile and is less fragile. In FIG. 14 , all elements are the same as FIG. 1 except portions of the p-layer 20 and active layer 18 are etched away during the LED forming process, and metal 50 (metallization layer plus bonding metal) contacts the n-layer 16 on the same side as the p-contact metal 24 . An underfill material 52 may be deposited in the voids beneath the LED to reduce thermal gradients across the LED, add mechanical strength to the attachment, and prevent contaminants from contacting the LED material. Since no top metal layer needs to be formed, the steps shown in FIGS. 7-11 may be skipped. The n-metal 50 and p-metal 24 are bonded to the pads 22 on the package substrate 12 .
FIG. 16 illustrates a flip chip LED 54 where the metal electrode 56 for the n-layer 16 is formed in a pattern across the n-layer to distribute the current. The metal electrode 56 is insulated from the p-contact metallization 58 by an insulating material 60 . The pattern of metal electrode 56 may be like fingers, a polka dot pattern, or any other pattern. Non-contiguous metal patterns require an additional insulating and conducting layer to make contact to all the metal portions.
An alternate process flow that would eliminate the need to dice the sapphire substrate wafer and allow for reuse of the sapphire substrate is also possible and described below. After fabrication of the flip-chip LEDs but before dicing, the LEDs are wafer-level tested and mapped according to their performance.
An array of separated package substrates 12 are prepared by surrounding the metal bonding regions on each package substrate with regions that are not affected by the LED bonding process, such that the portion of the package substrate extending beyond the LED die of interest does not damage or become bonded to adjacent LED dies on the wafer during the bonding process. Methods to render areas unaffected by the bonding process include a reduced height or coating with an inert film such as SiO 2 .
The wafer with the LEDs is placed in contact with a separated package substrate such that the first desired LED die is attached to the package substrate in a manner similar to the previously described method, using a combination of localized pressure, heat, and ultrasonic agitation.
The separation of the growth substrate from the bonded device (by pulling the package substrate from the sapphire substrate) follows, using the laser lift off method, localized to the die area. An optical pathway through the device attachment system would be required for the laser beam. An additional advantage of this substrate-reuse technique is that the pulling force could be maintained on the device during the growth substrate separation, increasing the LED's capacity for absorbing thermal shock associated with laser liftoff.
The LED structures of FIGS. 13A , 13 B, 15 , and 16 may be directly soldered to a circuit board or other connectors. Alternatively, the LED structures may be encapsulated in a secondary housing. FIG. 17 is an exploded view of one embodiment of the package substrate 12 with an LED die 10 mounted in a package. A heat-sinking slug 60 is placed into an insert-molded leadframe 62 . The insert-molded leadframe 62 is, for example, a filled plastic material molded around metal leads 64 that provide an electrical path. Slug 60 may include an optional reflector cup 66 . The LED die 10 attached to the package substrate 12 is mounted directly or indirectly to slug 60 . The metal leads 64 are bonded to the electrodes 26 ( FIG. 13A ) on the package substrate 12 . An optical lens 68 may be added.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.
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LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent application Ser. No. 09/907,512 filed on Jul. 16, 2001 entitled “High Resolution Overlay Alignment Methods and Systems for Imprint Lithography,” which claims priority to U.S. Provisional Patent Application No. 60/218,568 filed on Jul. 16, 2000 entitled “High-Resolution Overlay Alignment Methods and Systems for Imprint Lithography,” both of which are incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of N66001-98-1-8914 awarded by the Defense Advanced Research Projects Agency (DARPA).
BACKGROUND OF THE INVENTION
[0003] The present invention relates to methods and systems to achieve high-resolution overlay alignment for imprint lithography processes.
[0004] Imprint lithography is a technique that is capable of printing features that are smaller than 50 nm in size on a substrate. Imprint lithography may have the potential to replace photolithography as the choice for semiconductor manufacturing in the sub-100 nm regime. Several imprint lithography processes have been introduced during 1990s. However, most of them have limitations that preclude them from use as a practical substitute for photolithography. The limitations of these prior techniques include, for example, high temperature variations, the need for high pressures and the usage of flexible templates.
[0005] Recently, imprint lithography processes may be used to transfer high resolution patterns from a quartz template onto substrate surfaces at room temperature and with the use of low pressures. In the Step and Flash Imprint Lithography (SFIL) process, a rigid quartz template is brought into indirect contact with the substrate surface in the presence of light curable liquid material. The liquid material is cured by the application of light and the pattern of the template is imprinted into the cured liquid.
[0006] Using a rigid and transparent template makes it possible to implement high resolution overlay as part of the SFIL process. Also the use of a low viscosity liquid material that can be processed by light curing at low pressures and room temperatures lead to minimal undesirable layer distortions. Such distortions can make overlay alignment very difficult to implement.
[0007] Overlay alignment schemes typically include measurement of alignment errors between a template and the substrate, followed by compensation of these errors to achieve accurate alignment. The measurement techniques that are used in proximity lithography, x-ray lithography, and photolithography (such as laser interferometry, capacitance sensing, automated image processing of overlay marks on the mask and substrate, etc) may be adapted for the imprint lithography process with appropriate modifications. The compensation techniques have to be developed keeping in mind the specific aspects of imprint lithography processes.
[0008] Overlay errors that typically need to be compensated for include placement errors, theta error and magnification error. Overlay measurement techniques have been significantly improved during recent years as the minimum line width of photolithography processes have continued to shrink. However, these techniques may not be directly applicable to the imprint lithography processes.
SUMMARY OF THE INVENTION
[0009] The present invention includes an imprint lithography system for impinging a flux of light upon a liquid to polymerize the liquid, the system including, a source of light producing the flux of light; and a template having overlay marks being disposed between the liquid and the source of light and being opaque to the flux of light, with a pitch of the overlay marks establishing a polarization of the flux of light such that the flux of light impinges upon and polymerizes the liquid in superimposition with the overlay marks. These and other embodiments are described fully below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings in which:
[0011] FIGS. 1A and 1B depict a cross-sectional view of the gap between a template and a substrate;
[0012] FIGS. 2A-2E depict cross-sectional views of an imprint lithography process;
[0013] FIG. 3 depicts a process flow chart showing the sequence of steps of the imprint lithography process;
[0014] FIG. 4 depicts a bottom view of a patterned template;
[0015] FIG. 5 depicts a cross-sectional view of a template positioned over a substrate;
[0016] FIG. 6 depicts a cross sectional view of an imprint lithography process using a transfer layer;
[0017] FIG. 7 depicts a cross-sectional view of a process for forming an imprint lithography template;
[0018] FIGS. 8A-8C depict a cross-sectional views of patterned templates;
[0019] FIG. 9 depicts a cross sectional view of alternate patterned template designs;
[0020] FIGS. 10A-10B depict a top view of a process for applying a curable fluid to a substrate;
[0021] FIG. 11 depicts a schematic of an apparatus for dispensing a fluid during an imprint lithographic process;
[0022] FIG. 12 depicts fluid dispensing patterns used in an imprint lithographic process;
[0023] FIG. 13 depicts a fluid pattern that includes a plurality of drops on a substrate;
[0024] FIG. 14 depicts a schematic of an alternate apparatus for dispensing a fluid during an imprint lithographic process;
[0025] FIGS. 15A-15B depict a fluid pattern that includes a plurality of substantially parallel lines;
[0026] FIG. 16 depicts a projection view of a substrate support system;
[0027] FIG. 17 depicts a projection view of an alternate substrate support system;
[0028] FIG. 18 is a schematic diagram of a 4-bar linkage illustrating motion of the flexure joints;
[0029] FIG. 19 is a schematic diagram of a 4-bar linkage illustrating alternate motion of the flexure joints;
[0030] FIG. 20 is a projection view of a magnetic linear servo motor;
[0031] FIG. 21 is a process flow chart of global processing of multiple imprints;
[0032] FIG. 22 is a process flow chart of local processing of multiple imprints;
[0033] FIG. 23 is a projection view of the axis of rotation of a template with respect to a substrate;
[0034] FIG. 24 depicts a measuring device positioned over a patterned template;
[0035] FIG. 25 depicts a schematic of an optical alignment measuring device;
[0036] FIG. 26 depicts a scheme for determining the alignment of a template with respect to a substrate using alignment marks;
[0037] FIG. 27 depicts a scheme for determining the alignment of a template with respect to a substrate using alignment marks using polarized filters;
[0038] FIG. 28 depicts a schematic view of a capacitive template alignment measuring device;
[0039] FIG. 29 depicts a schematic view of a laser interferometer alignment measuring device;
[0040] FIG. 30 depicts a scheme for determining alignment with a gap between the template and substrate when the gap is partially filled with fluid;
[0041] FIG. 31 depicts an alignment mark that includes a plurality of etched lines;
[0042] FIG. 32 depicts a projection view of an orientation stage;
[0043] FIG. 33 depicts an exploded view of the orientation stage;
[0044] FIG. 34 depicts a process flow of a gap measurement technique;
[0045] FIG. 35 depicts a cross sectional view of a technique for determining the gap between two materials;
[0046] FIG. 36 depicts a graphical representation for determining local-minimum and maximum of a gap;
[0047] FIG. 37 depicts a template with gap measuring recesses;
[0048] FIG. 38 depicts a schematic for using an interferometer to measure a gap between a template and interferometer;
[0049] FIG. 39 depicts a schematic for probing the gap between a template and a substrate using a probe-prism combination;
[0050] FIG. 40 depicts a cross-sectional view of an imprint lithographic process;
[0051] FIG. 41 depicts a schematic of a process for illuminating a template;
[0052] FIGS. 42 A-B depict a projection view of a flexure member;
[0053] FIG. 43 depicts a first and second flexure member assembled for use;
[0054] FIG. 44 depicts a projection view of the bottom of an orientation stage;
[0055] FIG. 45 depicts a schematic view of a flexure arm;
[0056] FIG. 46 depicts a cross-sectional view of a pair of flexure arms;
[0057] FIG. 47 depicts a scheme for planarization of a substrate;
[0058] FIGS. 48 A-B depicts various views of a vacuum chuck for holding a substrate;
[0059] FIGS. 49 A-C depict a scheme for removing a template from a substrate after curing;
[0060] FIGS. 50 A-C depict a cross-sectional view of a method for removing a template from a substrate after curing;
[0061] FIGS. 51 A-B depict a schematic view of a template support system; and
[0062] FIG. 52 depicts a side view of a gap between a template and a substrate.
[0063] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawing and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0064] Embodiments presented herein generally relate to systems, devices, and related processes of manufacturing small devices. More specifically, embodiments presented herein relate to systems, devices, and related processes of imprint lithography. For example, these embodiments may have application to imprinting very small features on a substrate, such as a semiconductor wafer. It should be understood that these embodiments may also have application to other tasks, for example, the manufacture of cost-effective Micro-Electro-Mechanical Systems (or MEMS). Embodiments may also have application to the manufacture of other kinds of devices including, but not limited to: patterned magnetic media for data storage, micro-optical devices, biological and chemical devices, X-ray optical devices, etc.
[0065] With reference now to the figures, and specifically to FIGS. 1A and 1B , therein are shown arrangements of a template 12 predisposed with respect to a substrate 20 upon which desired features are to be imprinted using imprint lithography. Specifically, the template 12 may include a surface 14 that is fabricated to take on the shape of desired features which, in turn, may be transferred to the substrate 20 . In some embodiments, a transfer layer 18 may be placed between the substrate 20 and the template 12 . Transfer layer 18 may receive the desired features from the template 12 via imprinted layer 16 . As is well known in the art, transfer layer 18 may allow one to obtain high aspect ratio structures (or features) from low aspect ratio imprinted features.
[0066] For the purpose of imprint lithography, it is important to maintain the template 12 and substrate 20 as close to each other as possible and nearly parallel. For example, for features that are about 100 nm wide and about 100 nm deep, an average gap of about 200 nm or less with a variation of less than about 50 nm across the imprinting area of the substrate 20 may be required for the imprint lithography process to be successful. Embodiments presented herein provide a way of controlling the spacing between the template 12 and substrate 20 for successful imprint lithography given such tight and precise gap requirements.
[0067] FIGS. 1A and 1B illustrate two types of problems that may be encountered in imprint lithography. In. FIG. 1A , a wedge shaped imprinted layer 16 results because the template 12 is closer to the substrate 20 at one end of the imprinted layer 16 . FIG. 1A illustrates the importance of maintaining template 12 and substrate 20 substantially parallel during pattern transfer. FIG. 1B shows the imprinted layer 16 being too thick. Both of these conditions may be highly undesirable. Embodiments presented herein provide systems, processes and related devices which may eliminate the conditions illustrated in FIGS. 1A and 1B as well as other orientation problems associated with prior art lithography techniques.
[0068] FIGS. 2A through 2E illustrate an embodiment of an imprint lithography process, denoted generally as 30 . In FIG. 2A , template 12 may be orientated in spaced relation to the substrate 20 so that a gap 31 is formed in the space separating template 12 and substrate 20 . Surface 14 of template 12 may be treated with a thin layer 13 that lowers the template surface energy and assists in separation of template 12 from substrate 20 . The manner of orientation and devices for controlling gap 31 between template 12 and substrate 20 are discussed below. Next, gap 31 may be filled with a substance 40 that conforms to the shape of treated surface 14 . Alternately, in an embodiment, substance 40 may be dispensed upon substrate 20 prior to moving template 12 into a desired position relative to substrate 20 .
[0069] Substance 40 may form an imprinted layer such as imprinted layer 16 shown in FIGS. 1A and 1B . Preferably, substance 40 may be a liquid so that it may fill the space of gap 31 rather easily and quickly without the use of high temperatures and the gap can be closed without requiring high pressures. Further details regarding appropriate selections for substance 40 are discussed below.
[0070] A curing agent 32 may be applied to the template 12 causing substance 40 to harden and assume the shape of the space defined by gap 31 . In this way, desired features 44 ( FIG. 2D ) from the template 12 may be transferred to the upper surface of the substrate 20 . Transfer layer 18 may be provided directly on the upper surface of substrate 20 . Transfer layer 18 may facilitate the amplification of features transferred from the template 12 to generate high aspect ratio features.
[0071] As depicted in FIG. 2D , template 12 may be removed from substrate 20 leaving the desired features 44 thereon. The separation of template 12 from substrate 20 must be done so that desired features 44 remains intact without shearing or tearing from the surface of the substrate 20 . Embodiments presented herein provide a method and associated system for peeling and pulling (referred to herein as the “peel-and-pull” method) template 12 from substrate 20 following imprinting so that desired feature 44 remain intact.
[0072] Finally, in FIG. 2E , features 44 transferred from template 12 to substance 40 may be amplified in vertical size by the action of the transfer layer 18 as is known in the use of bilayer resist processes. The resulting structure may be further processed to complete the manufacturing process using well-known techniques. FIG. 3 summarizes an embodiment of an imprint lithography process, denoted generally as 50 , in flow chart form. Initially, at step 52 , course orientation of a template and a substrate may be performed so that a rough alignment of the template and substrate may be achieved. An advantage of course orientation at step 52 may be that it may allow pre-calibration in a manufacturing environment, where numerous devices are to be manufactured, with efficiency and with high production yields. For example, where the substrate includes one of many die on a semiconductor wafer, course alignment (step 52 ) may be performed once on the first die and applied to all other dies during a single production run. In this way, production cycle times may be reduced and yields may be increased.
[0073] At step 54 , a substance may be dispensed onto the substrate. The substance may be a curable organosilicon solution or other organic liquid that may become a solid when exposed to activating light. The fact that a liquid is used may eliminate the need for high temperatures and high pressures associated with prior art lithography techniques. Next, at step 56 , the spacing between the template and substrate may be controlled so that a relatively uniform gap may be created between the two layers permitting the precise orientation required for successful imprinting. Embodiments presented herein provide a device and system for achieving the orientation (both course and fine) required at step 56 .
[0074] At step 58 , the gap may be closed with fine vertical motion of the template with respect to the substrate and the substance. The substance may be cured (step 59 ) resulting in a hardening of the substance into a form having the features of the template. Next, the template may separated from the substrate, step 60 , resulting in features from the template being imprinted or transferred onto the substrate. Finally, the structure may be etched, step 62 , using a preliminary etch to remove residual material and a well-known oxygen etching technique to etch the transfer layer.
[0075] In various embodiments, a template may incorporate unpatterned regions i) in a plane with the template surface, ii) recessed in the template, iii) protrude from the template, or iv) a combination of the above. A template may be manufactured with protrusions, which may be rigid. Such protrusions may provide a uniform spacer layer useful for particle tolerance and optical devices such as gratings, holograms, etc. Alternately, a template may be manufactured with protrusions that are compressible.
[0076] In general, a template may have a rigid body supporting it via surface contact from: i) the sides, ii) the back, iii) the front or iv) a combination of the above. The template support may have the advantage of limiting template deformation or distortion under applied pressure. In some embodiments, a template may be coated in some regions with a reflective coating. In some such embodiments, the template may incorporate holes in the reflective coating such that light may pass into or through the template. Such coatings may be useful in locating the template for overlay corrections using interferometry. Such coatings may also allow curing with a curing agent source that illuminates through the sides of the template rather than the top. This may allow flexibility in the design of a template holder, of gap sensing techniques, and of overlay mark detection systems, among other things. Exposure of the template may be performed: i) at normal incidences to the template, ii) at inclined angles to the template, or iii) through a side surface of the template. In some embodiments, a template that is rigid may be used in combination with a flexible substrate.
[0077] The template may be manufactured using optical lithography, electron beam lithography, ion-beam lithography, x-ray lithography, extreme ultraviolet lithography, scanning probe lithography, focused ion beam milling, interferometric lithography, epitaxial growth, thin film deposition, chemical etch, plasma etch, ion milling, reactive ion etch or a combination of the above. The template may be formed on a substrate having a flat, parabolic, spherical, or other surface topography. The template may be used with a substrate having a flat, parabolic, spherical, or other surface topography. The substrate may contain a previously patterned topography and/or a film stack of multiple materials.
[0078] In an embodiment depicted in FIG. 4 , a template may include a patterning region 401 , an entrainment channel 402 , and an edge 403 . Template edge 403 may be utilized for holding the template within a template holder. Entrainment channel 402 may be configured to entrain excess fluid thereby preventing its spread to adjacent patterning areas, as discussed in more detail below. In some embodiments, a patterned region of a template may be flat. Such embodiments may be useful for planarizing a substrate.
[0079] In some embodiments, the template may be manufactured with a multi-depth design. That is, various features of the template may be at different depths with relation to the surface of the template. For example, entrainment channel 402 may have a depth greater than patterning area 401 . An advantage of such an embodiment may be that accuracy in sensing the gap between the template and substrate may be improved. Very small gaps (e.g., less than about 100 nm) may be difficult to sense; therefore, adding a step of a known depth to the template may enable more accurate gap sensing. An advantage of a dual-depth design may be that such a design may enable using a standardized template holder to hold an imprint template of a given size which may include dies of various sizes. A third advantage of a dual-depth design may enable using the peripheral region to hold the template. In such a system, all portions of the template and substrate interface having functional structures may be exposed to the curing agent. As depicted in FIG. 5 , a template 500 with the depth of the peripheral region 501 properly designed may abut adjacent imprints 502 , 503 . Additionally, the peripheral region 501 of imprint template 500 may remain a safe vertical distance away from imprints 503 .
[0080] A dual-depth imprint template, as described above, may be fabricated using various methods. In an embodiment depicted in FIG. 6 , a single, thick substrate 601 may be formed with both a high-resolution, shallow-depth die pattern 602 , and a low-resolution, large-depth peripheral pattern 603 . In an embodiment, as depicted in FIG. 7 , a thin substrate 702 (e.g., quartz wafer) may be formed having a high-resolution, shallow-depth die pattern 701 . Die pattern 701 may then be cut from substrate 702 . Die pattern 701 may then be bonded to a thicker substrate 703 , which has been sized to fit into an imprint template holder on an imprint machine. This bonding may be preferably achieved using an adhesive 704 with an index of refraction of the curing agent (e.g., UV light) similar to that of the template material.
[0081] Additional imprint template designs are depicted in FIGS. 8A, 8B , and 8 C and generally referenced by numerals 801 , 802 , and 803 , respectively. Each of template designs 801 , 802 and 803 may include recessed regions which may be used for gap measurement and or entrainment of excess fluid.
[0082] In an embodiment, a template may include a mechanism for controlling fluid spread that is based on the physical properties of the materials as well as geometry of the template. The amount of excess fluid which may be tolerated without causing loss of substrate area may limited by the surface energies of the various materials, the fluid density and template geometry. Accordingly, a relief structure may be used to entrain the excess fluid encompassing a region surrounding the desired molding or patterning area. This region may generally be referred to as the “kerf.” The relief structure in the kerf may be recessed into the template surface using standard processing techniques used to construct the pattern or mold relief structure, as discussed above.
[0083] In conventional photolithography, the use of optical proximity corrections in the photomasks design is becoming the standard to produce accurate patterns of the designed dimensions. Similar concepts may be applied to micro- and nano-molding or imprint lithography. A substantial difference in imprint lithography processes may be that errors may not be due to diffraction or optical interference but rather due to physical property changes that may occur during processing. These changes may determine the nature or the need for engineered relief corrections in the geometry of the template. A template in which a pattern relief structure is designed to accommodate material changes (such as shrinkage or expansion) during imprinting, similar in concept to optical proximity correction used in optical lithography, may eliminate errors due to these changes in physical properties. By accounting for changes in physical properties, such as volumetric expansion or contraction, relief structure may be adjusted to generate the exact desired replicated feature. For example, FIG. 9 depicts an example of an imprint formed without accounting for material property changes 901 , and an imprint formed accounting for changes in material properties 902 . In certain embodiments, a template with features having a substantially rectangular profile 904 , may be subject to deformations due to material shrinkage during curing. To compensate for such material shrinkage, template features may be provided with an angled profile 905 .
[0084] With respect to imprint lithography processes, the durability of the template and its release characteristics may be of concern. A durable template may be formed of a silicon or silicon dioxide substrate. Other suitable materials may include, but are not limited to: silicon germanium carbon, gallium nitride, silicon germanium, sapphire, gallium arsinide, epitaxial silicon, poly-silicon, gate oxide, quartz or combinations thereof. Templates may also include materials used to form detectable features, such as alignment markings. For example, detectable features may be formed of SiOx, where x is less than 2. In some embodiments x may be about 1.5. It is believed that this material may be opaque to visible light, but transparent to some activating light wavelengths.
[0085] It has been found through experimentation that the durability of the template may be improved by treating the template to form a thin layer on the surface of the template. For example, an alkylsilane, a fluoroalkylsilane, or a fluoroalkyltrichlorosilane layer may be formed on the surface, in particular tridecafluoro-1,1,2,2-tetrahydrooctyl trichlorosilane (C 5 F 13 C 2 H 4 SiCl 3 ) may be used. Such a treatment may form a self-assembled monolayer (SAM) on the surface of the template.
[0086] A surface treatment process may be optimized to yield low surface energy coatings. Such a coating may be used in preparing imprint templates for imprint lithography. Treated templates may have desirable release characteristics relative to untreated templates. For example, newly-treated templates may posses surface free energies, λ treated of about 14 dynes/cm. Untreated template surfaces may posses surface free energies, λ untreated about 65 dynes/cm. A treatment procedure disclosed herein may yield films exhibiting a high level of durability. Durability may be highly desirable since it may lead to a template that may withstand numerous imprints in a manufacturing setting.
[0087] A coatings for the template surface may be formed using either a liquid-phase process or a vapor-phase process. In a liquid-phase process, the substrate may be immersed in a solution of precursor and solvent. In a vapor-phase process, a precursor may be delivered via an inert carrier gas. It may be difficult to obtain a purely anhydrous solvent for use in liquid-phase treatments. Water in the bulk phase during treatment may result in clump deposition, which may adversely affect the final quality or coverage of the coating. In an embodiment of a vapor-phase process, the template may be placed in a vacuum chamber, after which the chamber may be cycle-purged to remove excess water. Some adsorbed water may remain on the surface of the template. A small amount of water may be needed to complete a surface reaction which forms the coating. It is believed that the reaction may be described by the formula:
R—SiCI3+3H2O=>R—Si(OH)3+3HCI
To facilitate the reaction, the template may be brought to a desired reaction temperature via a temperature-controlled chuck. The precursor may then be fed into the reaction chamber for a prescribed time. Reaction parameters such as template temperature, precursor concentration, flow geometries, etc. may be tailored to the specific precursor and template substrate combination.
[0088] As previously mentioned, substance 40 may be a liquid so that it may fill the space of gap 31 . For example, substance 40 may be a low viscosity liquid monomer solution. A suitable solution may have a viscosity ranging from about 0.01 cps to about 100 cps (measured at 25 degrees C.). Low viscosities are especially desirable for high-resolution (e.g., sub-100 nm) structures. In particular, in the sub-50 nm regime, the viscosity of the solution should be at or below about 25 cps, or more preferably below about 5 cps (measured at 25 degrees C.). In an embodiment, a suitable solution may include a mixture of 50% by weight n-butyl acrylate and 50% SIA 0210.0 (3-acryoloxypropyltristrimethylsiloxane) silane. To this solution may be added a small percentage of a polymerization initiator (e.g., a photo initiator). For example, a 3% by weight solution of a 1:1 Irg 819 and Irg 184 and 5% of sm 1402.0 may be suitable. The viscosity of this mixture is about 1 cps.
[0089] In an embodiment, an imprint lithography system may include automatic fluid dispensing method and system for dispensing fluid on the surface of a substrate (e.g., a semiconductor wafer). The dispensing method may use a modular automated fluid dispenser with one or more extended dispenser tips. The dispensing method may use an X-Y stage to generate relative lateral motions between the dispenser tip and the substrate. The method may eliminate several problems with imprint lithography using low viscosity fluids. For example, the method may eliminate air bubble trapping and localized deformation of an imprinting area. Embodiments may also provide a way of achieving low imprinting pressures while spreading the fluid across the entire gap between the imprinting template and the substrate, without unnecessary wastage of excess fluid.
[0090] In an embodiment, a dispensed volume may typically be less than about 130 nl (nano-liter) for a 1 inch 2 imprint area. After dispensing, subsequent processes may involve exposing the template and substrate assembly to a curing agent. Separation of the template from the substrate may leave a transferred image on top of the imprinted surface. The transferred image may lie on a thin layer of remaining exposed material. The remaining layer may be referred to as a “base layer.” The base layer should be thin and uniform for a manufacturable imprint.
[0091] Imprint processes may involve high pressures and/or high temperatures applied at the template and substrate interface. However, for the purpose of a manufacturable imprint lithography process including high resolution overlay alignment, high pressures and temperatures should be avoided. Embodiments disclosed herein avoid the need for high temperature by using low viscosity photo-curable fluids. Further, imprinting pressures may be minimized by reducing squeezing force required to spread the fluid across the entire imprinting area. Therefore, for the purpose of fluid based imprint lithography, a fluid dispense process should satisfy the following properties:
1. No air bubble should be trapped between template and substrate; 2. Direct contact between the dispenser tip and substrate should be avoided to minimize particle generation; 3. Pressure required to fill the gap between template and substrate should be minimized; 4. Non-uniform fluid buildup and/or pressure gradients should be minimized to reduce non-uniform localized deformation of template-substrate interface; and 5. Waste of the dispensed fluid should be minimized.
[0097] In some embodiments, relative motion between a displacement based fluid dispenser tip and a substrate may be used to form a pattern with substantially continuous lines on an imprinting area. Size of the cross section of the line and the shape of the line may be controlled by balancing rates of dispensing and relative motion. During the dispensing process, dispenser tips may be fixed near (e.g., on the order of tens of microns) the substrate. Two methods of forming a line pattern are depicted in FIGS. 10A and 10B . The pattern depicted in FIGS. 10A and 10B is a sinusoidal pattern; however, other patterns are possible. As depicted in FIGS. 10A and 10B a continuous line pattern may be drawn using either a single dispenser tip 1001 or multiple dispenser tips 1002 .
[0098] Dispensing rate, V d , and relative lateral velocity of a substrate, v s , may be related as follows:
V d =V d /t d (dispensing volume/dispensing period), (1)
V s =L/t d (line length/dispensing period), (2)
V d =a L (where, ‘a’ is the cross section area of line pattern), (3)
[0099] Therefore,
V d =a v s . (4)
The width of the initial line pattern may normally depend on the tip size of a dispenser. The tip dispenser may be fixed. In an embodiment, a fluid dispensing controller 1111 (as depicted in FIG. 11 ) may be used to control the volume of fluid dispensed (V d ) and the time taken to dispense the fluid (t d ). If V d and td are fixed, increasing the length of the line leads to lower height of the cross section of the line pattern. Increasing pattern length may be achieved by increasing the spatial frequency of the periodic patterns. Lower height of the pattern may lead to a decrease in the amount of fluid to be displaced during imprint processes. By using multiple tips connected to the same dispensing line, line patterns with long lengths may be formed faster as compared to the case of a single dispenser tip. In an embodiment, a displacement based fluid delivery system may include: a fluid container 1101 , an inlet tube 1102 , an inlet valve 1103 , an outlet valve 1104 , a syringe 1105 , a syringe actuator 1106 , a dispenser tip 1107 , an X stage actuator 1109 , a Y stage actuator 1110 , a dispenser controller 1111 , an XY stage controller 1112 , and a main control computer 1113 . A suitable displacement based dispenser may be available from the Hamilton Company.
[0100] FIG. 12 illustrates several undesirable fluid patterns or dispensing methods for low viscosity fluids. These dispensing patterns may lead to one or more problems, including: trapping air bubbles, localized deformations, and waste of fluid. For example, dispensing a single drop at the center of the imprinting area 1201 , or dispensing irregular lines 1205 may lead to localized deformations of the template and/or substrate. Dispensing several drops 1202 , or lines 1206 in a circumferential pattern may lead to trapping of air bubbles. Other dispensing patterns with nearly closed circumferential patterns 1204 may similarly lead to air bubble trapping. Likewise, spraying or random placement of droplets 1203 may lead to trapping of air bubbles. Spin-coating a substrate with a low viscosity fluid may cause a “dewetting” problem due to the thin film instability. Dewetting may lead to formation of numerous small drops of fluid on the substrate, instead of a thin uniform layer of fluid.
[0101] In an embodiment, a fluid dispensing method may dispense multiple small drops of liquid that may later be formed into a continuous body as they expand. FIG. 13 depicts the case of using five drops of liquid. Here, five drops are used only for the purpose of illustration. Other “open” patterns, such as a sinusoidal line, a ‘W’, or an ‘X’ may be implemented using this method. As the template-substrate gap decreases, circular drops 1301 may become thinner and wider causing neighboring drops to merge together 1302 . Therefore, even though the initial dispensing may not include a continuous form, the expanding liquid may expel air from the gap between the template and substrate. A pattern effective for use in this method should be dispensed in such a way that as droplets expand, they do not trap any air between the template and substrate.
[0102] Small drops of liquid whose volume may be accurately specified may be dispensed using micro-solenoid valves with a pressure-supporting unit. Another type of the liquid dispensing actuator may include a piezo-actuated dispenser. Advantages of a system with a micro-solenoid valve dispenser as compared to a displacement based fluid dispenser may include faster dispensing time and more accurate volume control. These advantages may be especially desirable for larger size imprints (e.g., several inches across). An embodiment of a system including micro-solenoid valves is depicted in FIG. 14 . The system may include: fluid container 1401 , an inlet tube 1402 , an inlet valve 1403 , a pump 1404 , an outlet valve 1405 , a pump controller 1406 , a micro-solenoid valve 1407 , a micro-solenoid valve controller 1408 , an X-y stage 1409 , an X-Y stage controller 1410 , and a main computer 1412 . A substrate 1411 may be placed on X-Y stage 1409 . A suitable micro-solenoid valve dispenser system may be available from the Lee Company.
[0103] A dispensing pattern that may be useful for large imprint areas (e.g., greater than several inches 2 ) is depicted in FIG. 15A . In such an embodiment, parallel lines of fluid 1503 may be dispensed. Parallel lines of fluid 1503 may be expanded in such a way that air may be expelled from the gap as template 1501 approaches substrate 1502 . To facilitate expanding lines 1503 in the desired manner, template 1501 may be close to the gap in an intentionally wedged configuration (as depicted in FIG. 15B ). That is, the template/substrate gap may be closed along lines 1503 (e.g., the wedge angle may be parallel to the lines 1503 ).
[0104] An advantage of providing a well-distributed initial fluid layer may be that the orientation error between the template and substrate may be compensated for. This may be due to the hydraulic dynamics of the thin layer of fluid and compliance of the orientation stage. The lower portion of the template may contact the dispensed fluid earlier than other portions of the template. As the gap between the template and substrate gets smaller, the imbalance of reaction forces between the lower and higher portions of the template increases. This imbalance of forces may lead to a correcting motion for the template and substrate, e.g., bring them into a substantially parallel relationship.
[0105] Successful imprint lithography may require precise alignment and orientation of the template with respect to the substrate to control the gap in between the template and substrate. Embodiments presented herein may provide a system capable of achieving precise alignment and gap control in a production fabrication process. In an embodiment, the system may include a high resolution X-Y translation stage. In an embodiment, the system may provide a pre-calibration stage for performing a preliminary and course alignment operation between the template and substrate surface to bring the relative alignment to within the motion range of a fine movement orientation stage. This pre-calibration stage may be required only when a new template is installed into the apparatus (also sometimes known as a stepper). The pre-calibration stage may consist of a base plate, a flexure component, and a plurality of micrometers or high resolution actuators coupling the base plate and the flexure component.
[0106] FIG. 16 depicts an embodiment of an X-Y translation stage in an assembled configuration, and generally referenced by numeral 1600 . The overall footprint may be less than about 20 inches by 20 inches and the height may be about 6 inches (including a wafer chuck). Such an embodiment may provide X and Y-axis translation ranges of motion of about 12 inches.
[0107] A second embodiment of an X-Y translation stage is depicted in FIG. 17 , and generally referenced by numeral 1700 . To provide a similar range of motion to that of X-Y stage 1600 , stage 1700 may have a foot print of about 29 inches by 29 inches and a height of about 15 inches (including a wafer chuck). Stages 1600 and 1700 differ mainly in that additional linkages 1701 are oriented vertically, thereby providing additional load bearing support for the translation stage.
[0108] Both X-Y stage 1600 and X-Y stage 1700 are flexure based systems. Flexures are widely used in precision machines since they may offer frictionless, particle-free and low maintenance operation. Flexures may also provide extremely high resolution. However, most flexure based systems may possess limited ranges of motion (e.g., sub mm range of motion). Embodiments disclosed herein may have a range of motion of more than 12 inches. It is believed that such stages may be cost-effective for lithographic applications, particularly in vacuum. Further, for imprint lithography techniques, the presence of imprint forces may give embodiments presented herein significant advantages.
[0109] In general, an X-Y stage may include two types of components: actuation components and load-carrying components. Lead screw assembly mechanisms have been widely used where the positioning accuracy is not a very significant factor. For high accuracy applications, ball screw assemblies have been used for both the actuating and load-carrying components. Both of these designs may be prone to problems of backlash and stiction. Further, the need for lubrication may make these designs undesirable for use in vacuum or in particle-sensitive applications (e.g., imprint lithography).
[0110] Additionally, some designs may utilize air bearings. Air bearings may substantially eliminate problems of stiction and backlash. However, air bearings may provide limited load bearing capacities. Additionally, air bearings may be unsuitable for use in vacuum environments.
[0111] FIG. 18 shows a schematic of portion of a basic linkage 1800 . Link 1 ( 1804 ) and link 3 ( 1805 ) may be of the same length. When a moving body 1801 moves along the X-axis, all of the joints in linkage 1800 rotate by the same absolute angle. It should be noted that the motion range may be independent of the length of link 2 ( 1803 ). Due to kinematic constraints, link 2 ( 1803 ) may remain parallel to a line between joint 1 ( 1806 ) and joint 4 ( 1807 ). In linkage 1800 , the range of motion, lm, may be given as:
l m =2 d 1 [cos(θ o −α max /2)−cos(θ o +α max /2)]=4 d 1 sin(θ o )sin(α max /2), (5)
where, θ o is the angle of joint 1 ( 1806 ) when all flexure joints are in their equilibrium conditions, α max is the maximum rotation range of the flexure pivots, and d 1 is the length of links 1 and 3 , ( 1804 ) and ( 1805 ). As shown in Eqn. (5), for given d 1 , the motion range is maximized when θ 0 =90 Degree. Therefore, the link length may be given as:
d 1 =l m /[4 sin(α max /2)] (6)
[0112] Therefore, using an α max of 60°, the minimum link length for a 12 inch motion range, is 6 inches.
[0113] FIG. 19 depicts an embodiment of a basic linkage similar to linkage 1800 , but with the addition of two cylindrical disks 1902 . A kinematic study shows that if joint 2 1904 and joint 3 1905 of FIG. 19 rotate in opposite directions by the same angle, the stage may generate a pure translational motion along the X axis. By adding cylindrical disks 1902 at flexure joints 2 1904 and 3 1905 , the resulting rolling contact may rotate link 1 1908 and link 2 1906 in opposite directions. In an embodiment, no additional joints or bearings may be required since cylindrical discs 1902 may be coupled to links 1908 and 1906 . In order to prevent discs 1902 from slipping, an appropriate pre-load may be applied between the two disks. Compared to conventional stages where direct driven mechanisms or bearings may be used, the contact surface here may be relatively small, and relatively easy to maintain. Note that although disks 1902 are not depicted in relation to X-Y stages 1600 , and 1700 , disks 1902 may be present in some embodiments. Links 1602 and 1601 in FIG. 16 may correspond to links 1908 and 1906 of FIG. 19 . Thus disks 1902 may be present at location 1603 (as well as other locations not visible in the FIG. 16 ). Referring to FIG. 17 , disks 1902 may be present at location 1702 (as well as other locations not visible in FIG. 17 ).
[0114] As the actuation system for either of stages 1600 or 1700 , two linear servo motors (as depicted in FIG. 20 and referenced by numeral 2000 ) may be suitable. One linear servo motor may serve each translation axis. Suitable linear servo motors may be available from the Trilogy Systems Corporation. An advantage of such linear servo motors may be the absence of frictional contact. Another advantage of such linear servo motors may be the fact that they may readily produces actuation forces greater than about 100 pounds. Therefore, actuation components may provide only translational motion control in the X and Y directions. It should be noted that in some embodiments, the actuator of the lower stage might need to be more powerful than the actuator of the upper stage. In some embodiments, laser interferometers may provide a feedback signal to control X and Y positioning of the X-Y stage. It is believed that laser interferometry may provide nm level positioning control.
[0115] Placement errors can be compensated using laser interferometers and high resolution X-Y stages (such as X-Y stage 1700 , depicted in FIG. 17 ). If the orientation alignments between the template and substrate are independent from X-Y motions, the placement error may need to be compensated only once for an entire substrate wafer (i.e., “global overlay”). If orientation alignments between the template and substrate are coupled with X-Y motions and/or excessive local orientation variations on substrate exist, then X-Y position changes of the template relative to the substrate may need to be compensated for (i.e., field-to-field overlay). Overlay alignment issues are further discussed with regard the overlay alignment section. FIGS. 21 and 22 provide global and field-to-field overlay error compensation algorithms, respectively.
[0116] In an embodiment, orientation of template and substrate may be achieved by a pre-calibration stage (automatically, using actuators or manual, using micrometers) and a fine orientation stage, which may be active or passive. Either or both of these stages may include other mechanisms, but flexure-based mechanisms may be preferred in order to avoid particles. The calibration stage may be mounted to a frame, and the fine orientation stage may be mounted to the pre-calibration stage. Such an embodiment may thereby form a serial mechanical arrangement.
[0117] A fine orientation stage may include one or more passive compliant members. A “passive compliant member” may generally refer to a member that gets its motion from compliance. That is, motion may be activated by direct or indirect contact with the liquid. If the fine orientation stage is passive, then it may be designed to have the most dominant compliance about two orientation axes. The two orientation axes may be orthogonal and may lie on the template lower surface (as described with referenced to FIG. 43 ). The two orthogonal torsional compliance values may typically be the same for a square template. The fine orientation stage may be designed such that when the template is non-parallel with respect to the substrate, as it makes contact with the liquid, the resulting uneven liquid pressure may rapidly correct the orientation error. In an embodiment, the correction may be affected with minimal, or no overshoot. Further, a fine orientation stage as described above may hold the substantially parallel orientation between the template and substrate for a sufficiently long period to allow curing of the liquid.
[0118] In an embodiment, a fine orientation stage may include one or more actuators. For example, piezo actuators (as described with reference to FIG. 46 ) may be suitable. In such an embodiment, the effective passive compliance of the fine orientation stage coupled with the pre-calibration stage should still be substantially torsional about the two orientation axes. The geometric and material parameters of all the structural and active elements together may contribute to this effective passive stiffness. For instance, piezo actuators may also be compliant in tension and compression. The geometric and material parameters may be synthesized to obtain the desired torsional compliance about the two orthogonal orientation axes. A simple approach to this synthesis may be to make the compliance of the actuators along their actuation direction in the fine orientation stage higher than the structural compliances in the rest of the stage system. This may provide passive self-correction capability when a non-parallel template comes into contact with the liquid on the substrate. Further, this compliance should be chosen to allow for rapidly correcting orientation errors, with minimal or no overshoot. The fine orientation stage may hold the substantially parallel orientation between the template and substrate for sufficiently long period to allow curing of the liquid.
[0119] Overlay alignment schemes may include measurement of alignment errors followed by compensation of these errors to achieve accurate alignment of an imprint template, and a desired imprint location on a substrate. The measurement techniques used in proximity lithography, x-ray lithography, and photolithography (e.g., laser interferometry, capacitance sensing, automated image processing of overlay marks on the mask and substrate, etc) may be adapted for the imprint lithography process with appropriate modifications.
[0120] Types of overlay errors for lithography processes may include placement error, theta error, magnification error, and mask distortion error. An advantage of embodiments disclosed herein may be that mask distortion errors may not be present because the disclosed processes may operate at relatively low temperatures (e.g., room temperature) and low pressures. Therefore, these embodiments may not induce significant distortion. Further, these embodiments may use templates that are made of a relatively thick substrate. This may lead to much smaller mask (or template) distortion errors as compared to other lithography processes where masks are made of relatively thin substrates. Further, the entire area of the templates for imprint lithography processes may be transparent to the curing agent (e.g., UV light), which may minimize heating due to absorption of energy from the curing agent. The reduced heating may minimize the occurrence of heat-induced distortions compared to photolithography processes where a significant portion of the bottom surface of a mask may be opaque due to the presence of a metallic coating.
[0121] Placement error may generally refer to X-Y positioning errors between a template and substrate (that is, translation along the X and/or Y-axis). Theta error may generally refer to the relative orientation error about Z-axis (that is, rotation about the Z-axis). Magnification error may generally refer to thermal or material induced shrinkage or expansion of the imprinted area as compared to the original patterned area on the template.
[0122] In imprint lithography processes, orientation alignment for gap control purposes between a template and substrate corresponding to the angles α and β in FIG. 23 may need to be performed frequently if excessive field-to-field surface variations exist on the substrate. In general, it is desirable for the variation across an imprinting area to be smaller than about one-half of the imprinted feature height. If orientation alignments are coupled with the X-Y positioning of the template and substrate, field-to-field placement error compensations may be necessary. However, embodiments of orientation stages that may perform orientation alignment without inducing placement errors are presented herein.
[0123] Photolithography processes that use a focusing lens system may position the mask and substrate such that it may be possible to locate the images of two alignment marks (one on the mask and the other on the substrate) onto the same focal plane. Alignment errors may be induced by looking at the relative positioning of these alignment marks. In imprint lithography processes, the template and substrate maintain a relatively small gap (of the order of micro meters or less) during the overlay error measurement. Therefore, overlay error measurement tools may need to focus two overlay marks from different planes onto the same focal plane. Such a requirement may not be critical for devices with features that are relatively large (e.g., about 0.5 J.lm). However, for critical features in the sub-100 nm region, the images of the two overlay marks should to be captured on the same focal plane in order to achieve high resolution overlay error measurements.
[0124] Accordingly, overlay error measurement and error compensation methods for imprint lithography processes should satisfy the following requirements:
[0125] 1. Overlay error measurement tools should be able to focus on two overlay marks that are not on the same plane;
[0126] 2. Overlay error correction tools should be able to move the template and substrate relatively in X and Y in the presence of a thin layer of fluid between the template and substrate;
[0127] 3. Overlay error correction tools should be able to compensate for theta error in the presence of a thin layer of fluid between the template and substrate; and
[0128] 4. Overlay error correction tools should be able to compensate for magnification error.
[0129] The first requirement presented above can be satisfied by i) moving an optical imaging tool up and down (as in U.S. Pat. No. 5,204,739) or ii) using illumination sources with two different wavelengths. For both these approaches, knowledge of the gap measurement between the template and the substrate is useful, especially for the second method. The gap between the template and substrate may be measured using one of existing non-contact film thickness measurement tools including broad-band interferometry, laser interferometry and capacitance sensors.
[0130] FIG. 24 illustrates the positions of template 2400 , substrate 2401 , fluid 2403 , gap 2405 and overlay error measurement tools 2402 . The height of a measuring tool may be adjusted 2406 according to the gap information to acquire two overlay marks on the same imaging plane. In order to fulfill this approach an image storing 2407 device may be required. Additionally, the positioning devices of the template and wafer should be vibrationally isolated from the up and down motions of the measuring device 2402 . Further, when scanning motions in X-Y directions between the template and substrate are needed for high resolution overlay alignment, this approach may not produce continuous images of the overlay marks. Therefore, this approach may be adapted for relatively low-resolution overlay alignment schemes for the imprint lithography process.
[0131] FIG. 25 illustrates an apparatus for focusing two alignment marks from different planes onto a single focal plane. Apparatus 2500 may use the change of focal length resulting from light with distinct wavelengths being used as the illumination sources. Apparatus 2500 may include an image storage device 2503 , and illumination source (not shown), and a focusing device 2505 . Light with distinct wavelengths may be generated either by using individual light sources or by using a single broad band light source and inserting optical band-pass filters between the imaging plane and the alignment marks. Depending on the gap between the template 2501 and substrate 2502 , a different set of two wavelengths may be selected to adjust the focal lengths. Under each illumination, each overlay mark may produce two images on the imaging plane as depicted in FIG. 26 . A first image 2601 may be a clearly focused image. A second image 2602 may be an out-of-focus image. In order to eliminate each out-of-focus image, several methods may be used.
[0132] In a first method, under illumination with a first wavelength of light, two images may be received by an imaging array (e.g., a CCD array). Images which may be received are depicted in FIG. 26 and generally referenced by numeral 2604 . Image 2602 may correspond to an overlay alignment mark on the substrate. Image 2601 may correspond to an overlay alignment mark on the template. When image 2602 is focused, image 2601 may be out-of-focus, and visa-versa. In an embodiment, an image processing technique may be used to erase geometric data corresponding to pixels associated with image 2602 . Thus, the out of focus image of the substrate mark may be eliminated, leaving image 2601 . Using the same procedure and a second wavelength of light, image 2605 and 2606 may be formed on the imaging array. The procedure may eliminate out of focus image 2606 . Thus image 2605 may remain. The two remaining focused images 2601 and 2605 may then be combined onto a single imaging plane 2603 for making overlay error measurements.
[0133] A second method may utilize two coplanar polarizing arrays, as depicted in FIG. 27 , and polarized illumination sources. FIG. 27 illustrates overlay marks 2701 and orthogonally polarized arrays 2702 . Polarizing arrays 2702 may be made on the template surface or may be placed above it. Under two polarized illumination sources, only focused images 2703 (each corresponding to a distinct wavelength and polarization) may appear on the imaging plane. Thus, out of focus images may be filtered out by polarizing arrays 2702 . An advantage of this method may be that it may not require an image processing technique to eliminate out-of-focused images.
[0134] It should be noted that, if the gap between the template and substrate is too small during overlay measurement, error correction may become difficult due to stiction or increased shear forces of the thin fluid layer. Additionally, overlay errors may be caused by the non-ideal vertical motion between the template and substrate if the gap is too large. Therefore, an optimal gap between the template and substrate should to be determined, where the overlay error measurements and corrections may be performed.
[0135] Moiré pattern based overlay measurement has been used for optical lithography processes. For imprint lithography processes, where two layers of Moiré patterns are not on the same plane but still overlapped in the imaging array, acquiring two individual focused images may be difficult to achieve. However, carefully controlling the gap between the template and substrate within the depth of focus of the optical measurement tool and without direct contact between the template and substrate may allow two layers of Moiré patterns to be simultaneously acquired with minimal focusing problems. It is believed that other standard overlay schemes based on the Moire patterns may be directly implemented to imprint lithography process.
[0136] Placement errors may be compensated for using capacitance sensors or laser interferometers, and high resolution X-Y stages. In an embodiment where orientation alignments between the template and substrate are independent from X-Y motions, placement error may need to be compensated for only once for an entire substrate (e.g., a semiconductor wafer). Such a method may be referred to as a “global overlay.” If orientation alignments between the template and substrate are coupled with X-Y motions and excessive local orientation variations exist on the substrate, X-Y position change of the template may be compensated for using capacitance sensors and/or laser interferometers. Such a method may be referred to as a “field-to-field overlay.” FIGS. 28 and 29 depict suitable sensor implementations. FIG. 28 depicts an embodiment of a capacitance sensing system. A capacitance sensing system may include capacitance sensors 2801 , a conductive coating 2802 , on a template 2803 . Thus, by sensing differences in capacitance, the location of template 2803 may be determined. Similarly, FIG. 29 depicts an embodiment of a laser interferometer system including reflective coating 2901 , laser signal 2902 and receiver 2903 . Laser signals received by receiver 2903 may be used to determine the location of template 2904 .
[0137] The magnification error, if any exists, may be compensated for by carefully controlling the temperature of the substrate and the template. Using the difference of the thermal expansion properties of the substrate and template, the size of pre-existing patterned areas on the substrate may be adjusted to that of a new template. However, it is believed that the magnification error may be much smaller in magnitude than placement error or theta error when an imprint lithography process is conducted at room temperature and low pressures.
[0138] The theta error may be compensated for using a theta stage that has been widely used for photolithography processes. Theta error may be compensated for by using two separate alignment marks that are separated by a sufficiently large distance to provide a high resolution theta error estimate. The theta error may be compensated for when the template is positioned a few microns apart from the substrate. Therefore, no shearing of existing patterns may occur.
[0139] Another concern with overlay alignment for imprint lithography processes that use UV curable liquid materials may be the visibility of the alignment marks. For the overlay error measurement, two overlay marks, one on the template and the other on the substrate may be used. However, since it may be desirable for the template to be transparent to a curing agent, the template overlay marks may typically not include opaque lines. Rather, the template overlay marks may be topographical features of the template surface. In some embodiment, the marks may be made of the same material as the template. In addition, UV curable liquids may tend to have refractive indices that are similar to those of the template materials (e.g., quartz). Therefore, when the UV curable liquid fills the gap between the template and the substrate, template overlay marks may become very difficult to recognize. If the template overlay marks are made with an opaque material (e.g., chromium), the UV curable liquid below the overlay marks may not be properly exposed to the UV light, which is highly undesirable.
[0140] Two methods are disclosed to overcome the problem of recognizing template overlay mark in the presence of the liquid. A first method uses an accurate liquid dispensing system along with high-resolution gap controlling stages. Suitable liquid dispensing systems and the gap controlling stages are disclosed herein. For the purpose of illustration, three steps of an overlay alignment are depicted in FIG. 30 . The locations of the overlay marks and the patterns of the fluid depicted in FIG. 30 are only for the purpose of illustration and should not be construed in a limiting sense. Various other overlay marks, overlay mark locations, and/or liquid dispensing patterns are also possible. First, in step 3001 , a liquid 3003 may be dispensed onto substrate 3002 . Then, in step 3004 , using the high-resolution orientation stage, the gap between template 3005 and substrate 3002 may be carefully controlled so that the dispensed fluid 3003 does not fill the gap between the template and substrate completely. It is believed that at step 3004 , the gap may be only slightly larger than the final imprinting gap. Since most of the gap is filled with the fluid, overlay correction can be performed as if the gap were completely filled with the fluid. The overlay marks may be placed such that the liquid does not cover them in this first position. Upon the completion of the overlay correction, the gap may be closed to a final imprinting gap (step 3006 ). This may enable spreading of the liquid into the remaining imprint area. Since the gap change between steps 3004 and 3006 may be very small (e.g., about 10 nm), the gap closing motion is unlikely to cause any significant overlay error.
[0141] A second method may be to make special overlay marks on the template that may be seen by the overlay measurement tool but may not be opaque to the curing agent (e.g., UV light). An embodiment of this approach is illustrated in FIG. 31 . In FIG. 31 , instead of completely opaque lines, overlay marks 3102 on the template may be formed of fine polarizing lines 3101 . For example, suitable fine polarizing lines may have a width about ½ to ¼ of the wavelength of activating light used as the curing agent. The line width of polarizing lines 3101 should be small enough so that activating light passing between two lines is diffracted sufficiently to cause curing of all the liquid below the lines. In such an embodiment, the activating light may be polarized according to the polarization of overlay marks 3102 . Polarizing the activating light may provide a relatively uniform exposure to all the template regions including regions having overlay marks 3102 . Light used to locate overlay marks 3102 on the template may be broadband light or a specific wavelength that may not cure the liquid material. This light need not be polarized. Polarized lines 3101 may be substantially opaque to the measuring light, thus making the overlay marks visible using established overlay error measuring tools. Fine polarized overlay marks may be fabricated on the template using existing techniques, such as electron beam lithography.
[0142] In a third embodiment, overlay marks may be formed of a different material than the template. For example, a material selected to form the template overlay marks may be substantially opaque to visible light, but transparent to activating light used as the curing agent (e.g., UV light). For example, SiOx where x is less than 2 may form such a material. In particular, it is believed that structures formed of SiOx where x is about 1.5 may be substantially opaque to visible light, but transparent to UV light.
[0143] FIG. 32 , depicts an assembly of a system, denoted generally as 100 , for calibrating and orienting a template, such as template 12 , about a substrate to be imprinted, such as substrate 20 . System 100 may be utilized in a machine, such as a stepper, for mass fabrication of devices in a production environment using imprint lithography processes as described herein. As shown, system 100 may be mounted to a top frame 110 which may provide support for a housing 120 . Housing 120 may contain the pre-calibration stage for course alignment of a template 150 about a substrate (not shown in FIG. 32 ).
[0144] Housing 120 may be coupled to a middle frame 114 with guide shafts 112 a, 112 b attached to middle frame 114 opposite housing 120 . In one embodiment, three (3) guide shafts may be used (the back guide shaft is not visible in FIG. 32 ) to provide a support for housing 120 as it slides up and down during vertical translation of template 150 . Sliders 116 a and 116 b attached to corresponding guide shafts 112 a, 112 b about middle frame 114 may facilitate this up and down motion of housing 120 .
[0145] System 100 may include a disk-shaped base plate 122 attached to the bottom portion of housing 120 . Base plate 122 may be coupled to a disk-shaped flexure ring 124 . Flexure ring 124 may support the lower placed orientation stage included in first flexure member 126 and second flexure member 128 . The operation and configuration of the flexure members 126 , 128 are discussed in detail below. As depicted in FIG. 33 , the second flexure member 128 may include a template support 130 , which may hold template 150 in place during the imprinting process. Typically, template 150 may include a piece of quartz with desired features imprinted on it. Template 150 may also include other substances according to well-known methods.
[0146] As shown in FIG. 33 , actuators 134 a, 134 b and 134 c may be fixed within housing 120 and operable coupled to base plate 122 and flexure ring 124 . In operation, actuators 134 a, 134 b and 134 c may be controlled such that motion of the flexure ring 124 is achieved. Motion of the actuators may allow for coarse pre-calibration. In some embodiments, actuators 134 a, 134 b and 134 c may include high resolution actuators. In such embodiments, the actuators may be equally spaced around housing 120 . Such an embodiment may permit very precise translation of the ring 124 in the vertical direction to control the gap accurately. Thus, the system 100 may be capable of achieving coarse orientation alignment and precise gap control of template 150 with respect to a substrate to be imprinted.
[0147] System 100 may include a mechanism that enables precise control of template 150 so that precise orientation alignment may be achieved and a uniform gap may be maintained by the template with respect to a substrate surface. Additionally, system 100 may provide a way of separating template 150 from the surface of the substrate following imprinting without shearing of features from the substrate surface. Precise alignment and gap control may be facilitated by the configuration of the first and second flexure members, 126 and 128 , respectively.
[0148] In an embodiment, template 5102 may be held in place using a separated, fixed supporting plate 5101 that is transparent to the curing agent as depicted in FIG. 51 . While supporting plate 5101 behind template 5102 may support the imprinting force, applying vacuum between fixed supporting plate 5101 and template 5102 may support the separation force. In order to support template 5102 for lateral forces, piezo actuators 5103 may be used. The lateral supporting forces may be carefully controlled by using piezo actuators 5103 . This design may also provide the magnification and distortion correction capability for layer-to-layer alignment in imprint lithography processes. Distortion correction may be very important to overcome stitching and placement errors present in the template structures made by electron beam lithography, and to compensate for distortion in the previous structures present on the substrate. Magnification correction may only require one piezo actuator on each side of the template (i.e. total of 4 piezo actuators for a four sided template). The actuators may be connected to the template surface in such a way that a uniform force may be applied on the entire surface. Distortion correction, on the other hand, may require several independent piezo actuators that may apply independently controlled forces on each side of the template. Depending on the level of distortion control required, the number of independent piezo actuators may be specified. More piezo actuators may provide better control of distortion. The magnification and distortion error correction should be completed prior to the use of vacuum to constrain the top surface of the template. This is because magnification and distortion correction may be properly controlled only if both the top and bottom surfaces of the template are unconstrained. In some embodiments, the template holder system of FIG. 51 may have a mechanical design that causes obstruction of the curing agent to a portion of the area under template 5102 . This may be undesirable because a portion of the liquid below template 5102 may not cure. This liquid may stick to the template causing problems with further use of the template. This problem with the template holder may be avoided by incorporating a set of mirrors into the template holder to divert the obstructed curing agent in such a way that the curing agent directed to the region below one edge of template 5102 may be bent to cure an obstructed portion below the other edge of template 5102 .
[0149] In an embodiment, high resolution gap sensing may be achieved by designing the template such that the minimum gap between the substrate and template falls within a sensing technique's usable range. The gap being measured may be manipulated independently of the actual patterned surface. This may allow gap control to be performed within the useful range of the sensing technique. For example, if a spectral reflectivity analysis technique with a useful sensing range of about 150 nm to 20 microns is to be used to analyze the gap, then the template may have feature patterned into the template with a depth of about 150 nm or greater. This may ensure that the minimum gap that to be sensed is greater than 150 nm.
[0150] As the template is lowered toward the substrate, the fluid may be expelled from the gap between the substrate and the template. The gap between the substrate and the template may approach a lower practical limit when the viscous forces approach equilibrium conditions with the applied compressive force. This may occur when the surface of the template is in close proximity to the substrate. For example, this regime may be at a gap height of about 100 nm for a 1 cP fluid when 14 kPa is applied for 1 sec to a template with a radius of 1 cm. As a result, the gap may be self-limiting provided a uniform and parallel gap is maintained. Also, a fairly predictable amount of fluid may be expelled (or entrained). The volume of fluid entrained may be predictable based on careful fluid dynamic and surface phenomena calculations.
[0151] For production-scale imprint patterning, it may be desired to control the inclination and gap of the template with respect to a substrate. In order to accomplish the orientation and gap control, a template manufactured with reticle fabrication techniques may be used in combination with gap sensing technology such as i) single wavelength interferometry, ii) multi-wavelength interferometry, iii) ellipsometry, iv) capacitance sensors, or v) pressure sensors.
[0152] In an embodiment, a method of detecting gap between template and substrate may be used in computing thickness of films on the substrate. A description of a technique based on Fast Fourier Transform (FFT) of reflective data obtained from a broad-band spectrometer is disclosed herein. This technique may be used for measuring the gap between the template and the substrate, as well as for measuring film thickness. For multi-layer films, the technique may provide an average thickness of each thin film and its thickness variations. Also, the average gap and orientation information between two surfaces in close proximity, such as the template-substrate for imprint lithography processes may be acquired by measuring gaps at a minimum of three distinct points through one of the surfaces.
[0153] In an embodiment, a gap measurement process may be based on the combination of the broad-band interferometry and Fast Fourier Transform (FFT). Several applications in current industry utilized various curve fitting techniques for the broad-band interferometry to measure a single layer film thickness. However, it is expected that such techniques may not provide real time gap measurements, especially in the case of multi-layer films, for imprint lithography processes. In order to overcome such problems, first the reflective indexes may be digitized in wavenumber domain, between 1/λ high and 1/λ low . Then, the digitized data may be processed using a FFT algorithm. This novel approach may yield a clear peak of the FFT signal that accurately corresponds to the measured gap. For the case of two layers, the FFT signal may yield two clear peaks that are linearly related to the thickness of each layer.
[0154] For optical thin films, the oscillations in the reflectivity are periodic in wavenumber (w)not wavelength (λ), such as shown in the reflectivity of a single optical thin film by the following equation,
R = ρ 1 , 2 2 + ρ 2 , 3 2 ⅇ - 2 α d - 2 ρ 1 , 2 ρ 2 , 3 ⅇ - α d cos ( 4 π n d / λ ) 1 - ( ρ 1 , 2 ρ 2 , 3 ) 2 ⅇ - 2 α d + 2 ρ 1 , 2 ρ 2 , 3 ⅇ - α d cos ( 4 π n d / λ )
where ρ i,i+1 are the reflectivity coefficients at the interface of the i−1 and i interface, n is the index of refraction, d is the thickness to measure of the film (material 2 of FIG. 52 ), and α is the absorption coefficient of the film (material 2 of FIG. 52 ). Here, w=I/λ.
[0155] Due to this characteristic, Fourier analysis may be a useful technique to determine the period of the function R represented in terms of w. It is noted that, for a single thin film, a clearly defined single peak (P l ) may result when a Fourier transform of R(w) is obtained. The film thickness (d) may be a function of the location of this peak such as,
d=P l /(Δ w× 2 n ), (8)
where Δw=W f −W s ; W f =l/λ min and W s =l/λ max .
[0156] FFT is an established technique in which the frequency of a discrete signal may be calculated in a computationally efficient way. Thus, this technique may be useful for in-situ analysis and real-time applications. FIG. 34 depicts an embodiment of a process flow of film thickness or gap, measurement via a FFT process of a reflectivity signal. For multi-layer films with distinct reflective indexes, locations of peaks in a FFT process may correspond to linear combinations of each film thickness. For example, a two-layer film may lead to two distinct peak locations in a FFT analysis. FIG. 35 depicts a method of determining the thickness of two films based on two peak locations.
[0157] Embodiments presented herein may enable measuring a gap or film thickness even when the oscillation of the reflectivity data includes less than one full period within the measuring wavenumber range. In such a case, FFT may result in an inaccurate peak location. In order to overcome such a problem and to extend the lower limit of the measurable film thickness, a novel method is disclosed herein. Instead of using a FFT algorithm to compute the period of the oscillation, an algorithm to find a local minimum (W 1 ) or maximum point (W 2 ) of the reflectivity between W s and W f may be used to compute the period information: dR/dw=0 at W 1 and W 2 . The reflectivity R(w) of Equation 7 has its maximum at w=O. Further, the wavenumber range (Δw) of typical spectrometers may be larger than W s . For a spectrometer with 200 nm-800 nm wavelength range, Δw=3/800 whereas W s =1/800. Therefore, the oscillation length of the reflectivity data between 0-W s may be smaller than that of Δw. As depicted in FIG. 36 , there may be two cases of the locations of minimum and maximum in the Δw range, given that w=0 is a maximum point of R(w). Therefore, the film thickness can be computed as follows:
Case 1 WWO: a local minimum exists at WI. Therefore, W 1 =one half of the periodic oscillation, and hence d=0.5/(w 1 ×2n). Case 2 WW 1 : a local maximum exists at W 2 . Therefore, W 2 =one period of the periodic oscillation, and hence d=1/(w 2 ×2n).
[0160] A practical configuration of the measurement tool may include a broad-band light source, a spectrometer with fiber optics, a data acquisition board, and a processing computer. Several existing signal processing techniques may improve the sensitivity of the FFT data. For example, techniques including but not limited to: filtering, magnification, increased number of data points, different range of wavelengths, etc., may be utilized with gap or film thickness measurement methods disclosed herein.
[0161] Embodiments disclosed herein include a high precision gap and orientation measurement method between two flats (e.g., a template and a substrate). Gap and orientation measurement methods presented here include use of broad-band interferometry and fringe based interferometry. In an embodiment, a method disclosed herein which uses broad-band interferometry may overcome a disadvantage of broad-band interferometer, namely its inability to accurately measure gaps smaller than about ¼ of the mean wavelength of the broad-band signal. Interference fringe based interferometry may be used for sensing errors in the orientation of the template soon after it is installed.
[0162] Imprint lithography processes may be implemented to manufacture single and multi-layer devices. Single layer devices, such as micron size optical mirrors, high resolution light filters and light guides, may be manufactured by forming a thin layer of material in certain geometric shapes on substrates. The imprinted layer thickness of some of these devices may be less than ¼ of the mean wavelength of a broad-band signal, and may be uniform across an active area. A disadvantage of broad-band interferometer may be that it may be unable to accurately measure gaps smaller than about ¼ of the mean wavelength of the broad-band signal (e.g., about 180 nm). In an embodiment, micrometer size steps, which may be measured accurately, may be etched into the surface of the template. As depicted in FIG. 37 , steps may be etched down in the forms of continuous lines 3701 or multiple isolated dots 3702 where measurements may be made. Isolated dots 3702 may be preferable from the point of view of maximizing the useful active area on the template. When the patterned template surface is only a few nanometers from the substrate, a broad-band interferometer may measure the gap accurately without suffering from minimum gap measurement problems.
[0163] FIG. 38 depicts a schematic of the gap measurement described here. Probes 3801 may also be used in an inclined configuration, such as depicted in FIG. 39 . If more than three probes are used, the gap measurement accuracy may be improved by using the redundant information. For simplicity's sake, the ensuing description assumes the use of three probes. The step size, h s , is magnified for the purpose of illustration. The average gap at the patterned area, h p , may be given as:
h p =[( h 1 +h 2 +h 3 )/3]− h s , (9)
When the positions of the probes are known ((X i , Y i ), where X and y axes are on the substrate surface), the relative orientation of the template with respect to the substrate may be expressed as a unit vector (D) that is normal to the template surface with respect to a frame whose x-y axes lie on the top surface of the substrate.
n=r/∥r∥, (10)
where, r=[(X 3 , Y 3 , h 3 )−(X 1 , Y 1 , h 1 )]×[(X 2 , Y 2 , h 2 )−(X 1 , Y 1 , h 1 )]. Perfect orientation alignment between two flats may be achieved when n=(00 I) T , or h 1 =h 2 =h 3 .
[0164] Measured gaps and orientations may be used as feedback information to imprinting actuators. The size of the measuring broad-band interferometric beam may be as small as about 75 μm. For a practical imprint lithography process, it may be desirable to minimize the clear area used only to measure the gap since no pattern can be etched into at the clear area. Further, blockage of the curing agent due to the presence of measurement tool should to be minimized.
[0165] FIG. 40 depicts a schematic of multi-layer materials on substrates. For example, substrate 4001 has layers 4002 , and 4003 , and fluid 4005 between substrate 4001 and template 4004 . These material layers may be used to transfer multiple patterns, one by one vertically, onto the substrate surface. Each thickness may be uniform at the clear area where a gap measurement may be made using light beams 4006 . It has been shown that using broad-band interferometry, the thickness of a top layer may be measured accurately in the presence of multi-layer films. When the optical properties and thicknesses of lower layer films are known accurately, the gap and orientation information between the template and substrate surface (or metal deposited surfaces for multi-layer devices) may be obtained by measuring the top layer thickness. The thickness of each layer may be measured using the same sensing measurement probes.
[0166] It may be necessary to perform orientation measurement and corresponding calibration when a new template is installed or a machine component is reconfigured. The orientation error between the template 4102 and substrate 4103 may be measured via an interference fringe pattern at the template and substrate interface as depicted in FIG. 41 . For two optical flats, the interference fringe pattern may appear as parallel dark and light bands 4101 . Orientation calibration may be performed using a pre-calibration stage as disclosed herein. Differential micrometers may be used to adjust the relative orientation of the template with respect to the substrate surface. Using this approach, if no interference fringe band is present, the orientation error may be corrected to be less than ¼ of the wavelength of light source used.
[0167] With reference to FIGS. 42A and 42B , therein are depicted embodiments of the first and second flexure members, 126 and 128 , respectively, in more detail. Specifically, the first flexure member 126 may include a plurality of flexure joints 160 coupled to corresponding rigid bodies 164 , 166 . Flexure joints 160 and rigid bodies 164 , and 166 may form part of arms 172 , 174 extending from a frame 170 . Flexure frame 170 may have an opening 182 , which may permit the penetration of a curing agent (e.g., UV light) to reach the template 150 when held in support 130 . In some embodiments, four (4) flexure joints 160 may provide motion of the flexure member 126 about a first orientation axis 180 . Frame 170 of first flexure member 126 may provide a coupling mechanism for joining with second flexure member 128 as illustrated in FIG. 43 .
[0168] Likewise, second flexure member 128 may include a pair of arms 202 , 204 extending from a frame 206 . Arms 202 and 204 may include flexure joints 162 and corresponding rigid bodies 208 , 210 . Rigid bodies 208 and 210 may be adapted to cause motion of flexure member 128 about a second orientation axis 200 . A template support 130 maybe integrated with frame 206 of the second flexure member 128 . Like frame 182 , frame 206 may have an opening 212 permitting a curing agent to reach template 150 which may be held by support 130 .
[0169] In operation, first flexure member 126 and second flexure member 128 may be joined as shown in FIG. 43 to form orientation stage 250 . Braces 220 , 222 may be provided in order to facilitate joining of the two pieces such that the first orientation axis 180 and second orientation axis 200 are substantially orthogonal to each other. In such a configuration, first orientation axis 180 and second orientation may intersect at a pivot point 252 at approximately the template substrate interface 254 . The fact that first orientation axis 180 and second orientation axis 200 are orthogonal and lie on interface 254 may provide fine alignment and gap control. Specifically, with this arrangement, a decoupling of orientation alignment from layer-to-layer overlay alignment may be achieved. Furthermore, as explained below, the relative position of first orientation axis 180 and second orientation axis 200 may provide an orientation stage 250 that may be used to separate the template 150 from a substrate without shearing of desired features. Thus, features transferred from the template 150 may remain intact on the substrate.
[0170] Referring to FIGS. 42A, 42B and 43 , flexure joints 160 and 162 may be notched shaped to provide motion of rigid bodies 164 , 166 , 208 , 210 about pivot axes that are located along the thinnest cross section of the notches. This configuration may provide two (2) flexure-based sub-systems for a fine decoupled orientation stage 250 having decoupled compliant motion axes 180 , 200 . Flexure members 126 , 128 may be assembled via mating of surfaces such that motion of template 150 may occur about pivot point 252 substantially eliminating “swinging” and other motions that could shear imprinted features from the substrate. Thus, orientation stage 250 may precisely move the template 150 about a pivot point 252 ; thereby, eliminating shearing of desired features from a substrate following imprint lithography.
[0171] Referring to FIG. 44 , during operation of system 100 , a Z-translation stage (not shown) may control the distance between template 150 and the substrate without providing orientation alignment. A pre-calibration stage 260 may perform a preliminary alignment operation between template 150 and the substrate surfaces to bring the relative alignment within the motion range limits of orientation stage 250 . In certain embodiments, pre-calibration may be required only when a new template is installed into the machine.
[0172] With reference to FIG. 45 , therein is depicted a flexure model, denoted generally as 300 , useful in understanding the principles of operation of a fine decoupled orientation stage, such as orientation stage 250 . Flexure model 300 may include four (4) parallel joints: joints 1 , 2 , 3 and 4 , that provide a four-bar-linkage system in its nominal and rotated configurations. Line 310 may pass though joints 1 and 2 . Line 312 may pass through joints 3 and 4 . Angles <:11 and <:12 may be selected so that the compliant alignment (or orientation axis) axis lies substantially on the template-wafer interface 254 . For fine orientation changes, rigid body 314 between joints 2 and 3 may rotate about an axis depicted by Point C. Rigid body 314 may be representative of rigid bodies 170 and 206 of flexure members 126 and 128 .
[0173] Mounting a second flexure component orthogonally onto the first one (as depicted in FIG. 43 ) may provide a device with two decoupled orientation axes that are orthogonal to each other and lie on the template-substrate interface 254 . The flexure components may be adapted to have openings to allow a curing agent (e.g., UV light) to pass through the template 150 .
[0174] The orientation stage 250 may be capable of fine alignment and precise motion of template 150 with respect to a substrate. Ideally, the orientation adjustment may lead to negligible lateral motion at the interface and negligible twisting motion about the normal to the interface surface due to selectively constrained high structural stiffness. Another advantage of flexure members 126 , 128 with flexure joints 160 , 162 may be that they may not generate particles as frictional joints may. This may be an important factor in the success of an imprint lithography process as particles may be particularly harmful to such processes.
[0175] Due to the need for fine gap control, embodiments presented herein may require the availability of a gap sensing method capable of measuring small gaps of the order of 500 nm or less between the template and substrate. Such a gap sensing method may require a resolution of about 50 nanometers, or less. Ideally, such gap sensing may be provided in real-time. Providing gap sensing in real-time may allow the gap sensing to be used to generate a feedback signal to actively control the actuators.
[0176] In an embodiment, a flexure member having active compliance may be provided. For example, FIG. 46 depicts a flexure member, denoted generally as 400 , including piezo actuators. Flexure member 400 may be combined with a second flexure member to form an active orientation stage. Flexure member 400 may generate pure tilting motions with no lateral motions at the template-substrate interface. Using such a flexure member, a single overlay alignment step may allow the imprinting of a layer on an entire semiconductor wafer. This is in contrast to overlay alignment with coupled motions between the orientation and lateral motions. Such overlay alignment steps may lead to disturbances in X-Y alignment, and therefore may require a complicated field-to-field overlay control loop to ensure proper alignment.
[0177] In an embodiment, flexure member 250 may possess high stiffness in the directions where side motions or rotations are undesirable and lower stiffness in directions where necessary orientation motions are desirable. Such an embodiment may provide a selectively compliant device. That is, flexure member 250 may support relatively high loads while achieving proper orientation kinematics between the template and the substrate.
[0178] With imprint lithography, it may be desirable to maintain a uniform gap between two nearly flat surfaces (i.e., the template and the substrate). Template 150 may be made from optical flat glass to ensure that it is substantially flat on the bottom. The template may be patterned using electron beam lithography. The substrate (e.g., a semiconductor wafer), however, may exhibit a “potato chip” effect resulting in micron-scale variations on its topography. Vacuum chuck 478 (as shown in FIG. 47 ), may eliminate variations across a surface of the substrate that may occur during imprinting.
[0179] Vacuum chuck 478 may serve two primary purposes. First, vacuum chuck 478 may be utilized to hold the substrate in place during imprinting and to ensure that the substrate stays flat during the imprinting process. Additionally, vacuum chuck 478 may ensure that no particles are present on the back of the substrate during processing. This may be especially important to imprint lithography, as particles may create problems that ruin the device and decrease production yields. FIG. 48A and 48B illustrate variations of a vacuum chuck suitable for these purposes according to two embodiments.
[0180] In FIG. 48A , a pin-type vacuum chuck 450 is shown as having a large number of pins 452 . It is believed that vacuum chuck 450 may eliminate “potato chip” effects as well as other deflections on the substrate during processing. A vacuum channel 454 may be provided as a means of applying vacuum to the substrate to keep it in place. The spacing between the pins 452 may be maintained such that the substrate will not bow substantially from the force applied through vacuum channel 454 . At the same time, the tips of pins 452 may be small enough to reduce the chance of particles settling on top of them.
[0181] FIG. 48B depicts a groove-type vacuum chuck 460 with a plurality of grooves 462 across its surface. Grooves 462 may perform a similar function to pins 454 of the pin-type vacuum chuck 450 . As shown, grooves 462 may take on either a wall shape 464 or a smooth curved cross section 466 . The cross section of grooves 462 for groove-type vacuum chuck 462 may be adjusted through an etching process. Also, the space and size of each groove may be as small as hundreds of microns. Vacuum flow to each of grooves 462 may be provided through fine vacuum channels across multiple grooves that run in parallel with respect to the chuck surface. The fine vacuum channels may be formed along with grooves through an etching process.
[0182] FIG. 47 illustrates the manufacturing process for both pin-type vacuum chuck 450 and groove-type vacuum chuck 460 . Using optical flat 470 , no additional grinding and/or polishing steps may be needed for this process. Drilling at determined locations on the optical flat 470 may produce vacuum flow holes 472 . Optical flat 470 may then be masked and patterned 474 before etching 476 to produce the desired features (e.g., pins or grooves) on the upper surface of the optical flat. The surface of optical flat 470 may then be treated 479 using well-known methods.
[0183] As discussed above, separation of template 150 from the imprinted layer may be a critical, final step in the imprint lithography process. Since the template 150 and substrate may be almost perfectly parallel, the assembly of the template, imprinted layer, and substrate leads to a substantially uniform contact between near optical flats. Such a system may usually require a large separation force. In the case of a flexible template or substrate, the separation may be merely a “peeling process.” However, a flexible template or substrate may be undesirable from the point of view of high-resolution overlay alignment. In case of quartz template and silicon substrate, the peeling process may not be implemented easily. However, separation of the template from an imprinted layer may be performed successfully by a “peel and pull” process. A first peel and pull process is illustrated in FIGS. 49A, 49B , and 49 C. A second peel and pull process is illustrated in FIGS. 50A, 50B , and 50 C. A process to separate the template from the imprinted layer may include a combination of the first and second peel and pull processes.
[0184] For clarity, reference numerals 12 , 18 , 20 , and 40 are used in referring to the template, transfer layer, substrate, and curable substance, respectively, in accordance with FIGS. 1A and 1B . After curing of the substance 40 , either the template 12 or substrate 20 may be tilted to intentionally induce an angle 500 between the template 12 and substrate 20 . Orientation stage 250 may be used for this purpose. Substrate 20 is held in place by vacuum chuck 478 . The relative lateral motion between the template 12 and substrate 20 may be insignificant during the tilting motion if the tilting axis is located close to the template-substrate interface. Once angle 500 between template 12 and substrate 20 is large enough, template 12 may be separated from the substrate 20 using only Z-axis motion (i.e. vertical motion). This peel and pull method may result in desired features 44 being left intact on the transfer layer 18 and substrate 20 without undesirable shearing.
[0185] A second peel and pull method is illustrated in FIGS. 50A, 50B , 50 C. In the second peel and pull method, one or more piezo actuators 502 may be installed adjacent to the template. The one or more piezo actuators 502 may be used to induce a relative tilt between template 12 and substrate 20 ( FIG. 50A ). An end of piezo actuator 502 may be in contact with substrate 20 . Thus, if actuator 502 is enlarged ( FIG. 50B ), template 12 may be pushed away from substrate 20 ; thus inducing an angle between them. A Z-axis motion between the template 12 and substrate 20 ( FIG. 50C ), may then be used to separate template 12 and substrate 20 . An end of actuator 502 may be surface treated similar to the treatment of the lower surface of template 12 in order to prevent the imprinted layer from sticking to the surface of the actuator.
[0186] In summary, embodiments presented herein disclose systems, processes and related devices for successful imprint lithography without requiring the use of high temperatures or high pressures. With certain embodiments, precise control of the gap between a template and a substrate on which desired features from the template are to be transferred may be achieved. Moreover, separation of the template from the substrate (and the imprinted layer) may be possible without destruction or shearing of desired features. Embodiments herein also disclose a way, in the form of suitable vacuum chucks, of holding a substrate in place during imprint lithography. Further embodiments include, a high precision X-Y translation stage suitable for use in an imprint lithography system. Additionally, methods of forming and treating a suitable imprint lithography template are provided.
[0187] While this invention has been described with references to various illustrative embodiments, the description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
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The present invention includes an imprint lithography system for impinging a flux of light upon a liquid to polymerize the liquid, the system including, a source of light producing the flux of light; and a template having overlay marks being disposed between the liquid and the source of light and being opaque to the flux of light, with a pitch of the overlay marks establishing a polarization of the flux of light such that the flux of light impinges upon and polymerizes the liquid in superimposition with the overlay marks.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a Divisional of co-pending U.S. patent application Ser. No. 09/432,704 filed Nov. 2, 1999, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
The present invention generally relates to measurement of the distance of a shaft from the bottom of a vessel and the amount by which the shaft is offset from the center of the vessel. More particularly, the present invention relates to the precise measurement of shaft height and shaft offset in vessels employed in dissolution testing systems.
BACKGROUND ART
In the pharmaceutical industry, dissolution testing and analysis is required to be performed on samples taken from batches of tablets or capsules manufactured by pharmaceutical companies in order to assess efficacy and other properties. Dissolution analysis by automated means has become popular for increasing throughput and improving accuracy, precision, reliability, and reproducibility. Automation also relieves the tedium of manually performing a variety of requisite procedures, including: handling and delivering dosage units such as capsules and tablets; monitoring dissolution system parameters; manipulating the shafts carrying the agitation paddles or sample baskets; recording, displaying and printing accumulated data and test results; and cleaning and filtering the vessels employed in such procedures.
Despite the benefits accruing from automation, validation of the procedures employed in dissolution testing and analysis remains a critical consideration. A typical dissolution test requires, among other things, that a rotatable shaft equipped with a paddle or basket be properly positioned in the center of, and properly located a specified distance from the bottom of, a dissolution test vessel prior to conducting the test. The USP has promulgated guidelines for the pharmaceutical industry which are enforced by the FDA. Under USP 24, General Chapters, Dissolution (711), the shaft must be positioned such that its centerline is not more than 2 mm at any point from the vertical axis of the vessel, and such that the paddle or basket (typically mounted to the lower end of the shaft) be positioned at 25 mm±2 mm from the bottom of the vessel.
Various hand-held devices have been utilized to carry out the measurements required to determine whether a shaft is positioned in a dissolution test vessel in compliance with the above-cited guidelines. Rulers, machinist calipers and micrometers, and pass/fail fixtures typify such devices and are known to persons skilled in the art. It is readily apparent to such skilled persons that operation of these devices requires a great deal of manual handling, with critical specifications largely determined by sight and feel. Conventional shaft measurement devices therefore engender an unacceptably high risk of error. There accordingly exists a long felt need for improved apparatus and methods for determining the position of a shaft installed in the vessel of a dissolution testing station.
DISCLOSURE OF THE INVENTION
In accordance with the present invention, an apparatus is mountable to a shaft disposed within a vessel and is adapted for measuring the magnitude by which the centerline of the shaft is offset from the central axis of the vessel. The apparatus comprises a housing and a plunger slidably mounted to the housing. The plunger has an outer section extending radially outwardly beyond a wall of the housing, and means such as a spring for biasing the plunger radially outwardly. A transducer is operatively mounted to the housing. The transducer is adapted to encode positions of the plunger and to produce an electrical signal proportional to a change in position resulting from displacement of the plunger. Means such as data lines are provided for transferring the signal to means such as a microprocessor for interpreting the signal.
In another embodiment according to the present invention, an apparatus is mountable to a shaft having a paddle or basket disposed within a vessel. The vessel has a central axis and a hemispherical end region. The apparatus is adapted for measuring the distance from a distal surface of the paddle or basket to a lowermost point on the inside surface of the hemispherical end region. The apparatus comprises a housing and a plunger slidably mounted to the housing. The plunger has an outer section extending outwardly beyond a wall of the housing, and means such as a spring for biasing the plunger outwardly. An end portion extends transversely from the plunger beneath the housing and is substantially centered about a central portion of the housing. A transducer is operatively mounted to the housing. The transducer is adapted to encode positions of the plunger and to produce an electrical signal proportional to a change in position resulting from displacement of the plunger. Means such as data lines are provided for transferring the signal to means such as a microprocessor for interpreting the signal.
In another embodiment according to the present invention, a system is provided for determining the location of a rotatable shaft in relation to a vessel mounted to a rack of a dissolution testing station. The shaft has a first end mounted to the testing station above the vessel, a second end disposed within the vessel and an operative component secured to the second end. The system comprises a housing including means such as a resilient clip and groove for removably mounting the housing to the shaft, and a plunger slidably mounted to the housing. The plunger has an outer section extending radially outwardly beyond a wall of the housing and extendable to an inside lateral surface of the vessel, and has means such as a spring for biasing the plunger radially outwardly. A transducer is operatively mounted to the housing. The transducer is adapted to encode positions of the plunger, and to produce an electrical signal proportional to a distance from a reference position to an extended position at which the plunger is in contact with the inside lateral surface of the vessel. Means such as data lines are provided for transferring the signal to means such as a microprocessor for interpreting the signal.
In another embodiment according to the present invention, a system is provided for determining the location of a rotatable shaft in relation to a vessel. The vessel has a central axis and a hemispherical end region, and is mounted to a rack of a dissolution testing station. The shaft has a first end mounted to the testing station above the vessel, a second end disposed within the vessel and an operative component such as a paddle or basket secured to the second end. The system comprises a spherical object removably disposed in a lowermost point on an inside surface of the hemispherical end region of the vessel. A housing includes means such as a resilient clip or groove for removably mounting the housing to the shaft. A plunger is slidably mounted to the housing. The plunger has an outer section extending beyond a wall of the housing and extendable to the spherical object, and has means such as a spring for biasing the plunger outwardly. An end portion has an upper surface and a lower surface, and extends transversely from the plunger and between the operative component and the spherical object.
A transducer is operatively mounted to the housing. The transducer is adapted to encode positions of the plunger, and to produce an electrical signal proportional to a distance from a reference position at which the top surface of the end portion of the plunger is biased against the operative component to an extended position at which the lower surface is in contact with the spherical object. Means such as data lines are provided for transferring the signal to means such as a microprocessor for interpreting the signal.
In another object according to the present invention, a system is provided for determining the location of a shaft in relation to a vessel in which the shaft is disposed. The vessel has a central axis and a hemispherical end region. The system comprises a shaft offset measurement device which includes a first housing and a first plunger slidably mounted to the first housing. The first plunger has an outer section extending radially outwardly beyond a wall of the first housing and means such as a spring for biasing the first plunger radially outwardly. A first transducer is operatively mounted to the first housing. The first transducer is adapted to encode positions of the first plunger and to produce a first electrical signal proportional to a change in position resulting from displacement of the first plunger.
The system further comprises a shaft height measurement device which includes a second housing and a second plunger slidably mounted to the second housing. The second plunger has an outer section extending outwardly beyond a wall of the second housing, and means such as a spring for biasing the second plunger outwardly. An end portion extends transversely from the second plunger beneath the second housing and is substantially centered about a central portion of the second housing. A second transducer is operatively mounted to the second housing. The second transducer is adapted to encode positions of the second plunger and to produce a second electrical signal proportional to a change in position resulting from displacement of the second plunger.
The system further comprises a console including logic means such as a microprocessor for effecting interpretations of the first and second electrical signals and means such as an LCD display for displaying the interpretations in human-readable form. Means such as data lines are provided for transferring the first and second electrical signals to the logic means.
In another embodiment according to the present invention, an apparatus is adapted for measuring the magnitude by which the centerline of a shaft is offset from the central axis of a vessel in which the shaft is disposed, and for measuring the distance from a distal end of the shaft to the lowermost point on an inside surface of a hemispherical end region of the vessel. The apparatus comprises a mounting assembly, a lateral plunger slidably mounted to the mounting assembly, a lateral transducer operatively disposed with respect to the mounting assembly and to the lateral plunger, a vertical plunger slidably mounted to the mounting assembly, and a vertical transducer operatively disposed with respect to the mounting assembly and to the vertical plunger.
The lateral plunger has means such as a spring for biasing the lateral plunger radially outwardly. The lateral transducer is adapted to encode positions of the lateral plunger and to produce an electrical signal proportional to a change in position resulting from displacement of the lateral plunger. The vertical plunger has means such as a spring for biasing the vertical plunger downwardly with respect to the mounting assembly, and includes an upper end portion extending transversely from the vertical plunger. The vertical transducer is adapted to encode positions of the vertical plunger and to produce an electrical signal proportional to a change in position resulting from displacement of the vertical plunger. Means such as data lines are provided for transferring the signals produced respectively by the lateral and vertical transducers to means for interpreting the signals. The signal interpreting means can include a console with which the signal transferring means communicates, wherein the console has logic means such as a microprocessor for effecting interpretations of the signals and means such as an LCD display for displaying the interpretations in human-readable form.
The present invention also provides methods for determining the position of a shaft installed in a vessel with respect to the central axis of the vessel and/or lowermost point inside the vessel.
Accordingly, a method is provided for measuring the amount by which the centerline of a shaft is offset from the central axis of a vessel in which the shaft is to be disposed, comprising the following steps. A measurement device which includes a radially outwardly biased plunger is mounted to the shaft. The plunger has a settable zero reference position. The shaft is inserted into the vessel at a normal operating position of the shaft, wherein a distal end of the plunger is in contact with a lateral inside surface of the vessel at a first distal plunger position. A first displaced plunger position is defined as a position on the plunger located a distance by which the plunger has moved in relation to the zero reference position, the distance being equal a first displacement magnitude.
The displacement magnitudes are measured by encoding the displaced plunger position and interpreting the displaced plunger position in relation to the zero reference position, wherein the displacement magnitudes determine the shaft centerline offset amount. A value for the shaft centerline offset amount is calculated based on the measured first displacement magnitudes. Finally, a signal is produced which is indicative of the shaft centerline offset amount.
Accordingly, another method is provided wherein a distal end of the plunger position is in contact with a lateral inside surface of the vessel at a first distal plunger position. This first displaced plunger position is reset to the zero reference position. The shaft is then rotated one full revolution while continuously sampling the displacement of the plunger position is defined as a position on the plunger located a distance by which the plunger has moved in relation to the zero reference position, the distance being equal to the displacement magnitude from this continuous sampling, the lowest and the largest displacement magnitudes are kept.
Another method according to the present invention is for measuring a shaft height, which is defined as the distance between the distal end of a shaft and the inside lowermost surface of a hemispherical end region of a vessel in which the shaft is to be disposed. The method comprises the following steps. A measurement device which includes a downwardly biased plunger is mounted to the shaft. The plunger includes an end portion. The end portion extends below the shaft and has a predetermined end portion height. A zero reference position of the plunger is defined by urging the end portion against the distal end of the shaft. The zero reference position is encoded. The inside lowermost surface of the hemispherical end region of the vessel is located by inserting a spherical object having a predetermined diameter into the vessel. The shaft is inserted into the vessel at a normal operating position of the shaft, permitting the end portion of the plunger to contact the spherical object.
A displaced plunger position is defined as a position on the plunger located a distance by which the plunger has moved in relation to the zero reference position in order to contact the spherical object, the distance being equal to a displacement magnitude. The displacement magnitude is measured by encoding the displaced plunger position and interpreting the displaced plunger position in relation to the zero reference position, wherein the sum of a predetermined constant plus the displacement magnitude is proportional to the shaft height. A value for the shaft height is calculated based on the measured displacement magnitude. A signal is produced which is indicative of the shaft height.
A further method according to the present invention is for measuring the amount by which the centerline of a shaft is offset from the central axis of a vessel in which the shaft is to be disposed, and for measuring a shaft height defined as the distance between the distal end of the shaft and the inside lowermost surface of a hemispherical end region of the vessel. The method comprises the following steps. The inside lowermost surface of the hemispherical end region of the vessel is located by inserting a spherical object into the vessel. A measurement device is mounted over the vessel. The measurement device includes a lateral plunger and a vertical plunger. The vertical plunger includes an end portion. The shaft is inserted into the vessel at a normal operating position of the shaft.
A distal end of the lateral plunger is permitted to contact a lateral inside surface of the vessel. A displaced lateral plunger position is defined as a position on the lateral plunger located a lateral distance by which the lateral plunger has moved in relation to a predetermined zero reference position of the lateral plunger, the lateral distance being equal to a lateral displacement magnitude. The lateral displacement magnitude is measured by encoding the displaced lateral plunger position and interpreting the displaced lateral plunger position in relation to the zero reference position of the lateral plunger, wherein the lateral displacement magnitude determines the shaft centerline offset amount. A value for the shaft centerline offset amount is calculated based on the measured lateral displacement magnitude. A signal is produced which is indicative of the shaft centerline offset amount.
The end portion of the vertical plunger is permitted to contact the spherical object. A displaced vertical plunger position is defined as a position on the vertical plunger located a vertical distance by which the vertical plunger has moved in relation to a predetermined zero reference position of the plunger, the vertical distance being equal to a vertical displacement magnitude. The vertical displacement magnitude is measured by encoding the displaced vertical plunger position and interpreting the displaced vertical plunger position in relation to the zero reference position of the vertical plunger, wherein the vertical displacement magnitude determines the shaft height. A value for the shaft height is calculated based on the measured vertical displacement magnitude. A signal is produced which is indicative of the shaft height.
It is therefore an object of the present invention to provide an apparatus for measuring the amount by which the centerline of a shaft disposed in a vessel is offset from the central vertical axis of the vessel.
It is another object of the present invention to provide an apparatus for measuring the height of such shaft above the lowermost inside point of the vessel.
It is a further object of the present invention to provide an apparatus for controlling the process by which the shaft centerline offset amount and shaft height are measured, and for expressing the results of such process using peripheral devices.
It is yet another object of the present invention to provide improved methods for determining accurate values for the shaft centerline offset amount and shaft height.
Some of the objects of the invention having been stated hereinabove, other objects will become evident as the description proceeds, when taken in connection with the accompanying drawings as best described hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a paddle shaft installed in a vessel in which the present invention is implemented;
FIG. 2 is a perspective view of a dissolution testing station in which the present invention is implemented;
FIG. 3A is a perspective view of a shaft centerline offset and height measurement system according to the present invention;
FIG. 3B is a perspective view of a shaft height measurement device according to the present invention;
FIG. 3C is a perspective view of a shaft centerline offset measurement device according to the present invention;
FIG. 4A is a front elevation view of the shaft centerline offset measurement device in FIG. 3C;
FIG. 4B is a rear elevation view of the shaft centerline offset measurement device in FIG. 3C;
FIG. 4C is a top plan view of the shaft centerline offset measurement device in FIG. 3C;
FIG. 4D is a bottom plan view of the shaft centerline offset measurement device in FIG. 3C;
FIG. 5A is a front elevation view of the shaft height measurement device in FIG. 3B;
FIG. 5B is a rear elevation view of the shaft height measurement device in FIG. 3B;
FIG. 5C is a top plan view of the shaft height measurement device in FIG. 3B;
FIG. 5D is a bottom plan view of the shaft height measurement device in FIG. 3B;
FIGS. 6A and 6B are front and rear elevation views, respectively, of a shaft centerline offset measurement device mounted to a shaft within a vessel according to the present invention;
FIGS. 7A and 7B are front and rear elevation views, respectively, of a shaft height measurement device mounted to a shaft within a vessel according to the present invention;
FIGS. 8A, 8 B and 8 C are geometric views illustrating a method for calculating the offset amount of the centerline of a shaft according to the present invention;
FIG. 9 is a geometric view illustrating another method for calculating the offset amount of the centerline of a shaft according to the present invention;
FIGS. 10A and 10B are perspective views of a combined shaft centerline offset and height measurement device according to the present invention;
FIGS. 11A and 11B are detailed perspective views of a shaft centerline offset measurement module of the device in FIGS. 10A and 10B;
FIG. 12 is a detailed perspective view of a shaft height measurement module of the device in FIGS. 10A and 10B; and
FIGS. 13A and 13B are a flow diagram of a test routine according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a typical vessel V employed in a dissolution testing station, while FIG. 2 illustrates one such testing station generally designated DTS. Vessel V has an open upper end 12 , a lateral side region 14 , and a hemispherical end region 16 . A plurality of vessels V (typically 6 or 8) are mounted in a rack 18 of dissolution testing station DTS for high-throughput testing. Each vessel V is centered and locked into position on rack 18 with the aid of a vessel centering ring CR (not shown in FIG. 2 ). Dissolution testing station DTS includes, among other components, a water bath WB for temperature control of vessels V and a programmable systems control module 20 having peripheral elements such as an LCD display 20 A, a keypad 20 B, and individual readouts 20 C. A shaft S provided with a paddle or basket P may be inserted into each vessel V. One or more spindle motors (not shown) housed within control module 20 drive the rotation of shafts S through a chuck (not shown) or equivalent coupling means. Referring specifically to FIG. 1, the parameters of shaft position relative to vessel V sought to be determined are shaft centerline offset determined by shaft distance x, and shaft or paddle height y. The present invention described in detail below has been found by applicants to measure these parameters accurately to within 0.1 mm.
FIGS. 3A through 3C show a shaft centerline offset and height measurement system according to the present invention and generally designated 30 . Primary components of measurement system include a shaft centerline offset measurement device generally designated 40 , a height measurement device generally designated 50 , and a control/display console generally designated 60 . Control/display console 60 is portable and thus includes a handle 60 A. A keypad 60 B is provided for inputting commands, calibration data, and the like. Results derived from measurements taken by centerline offset and height measurement devices 40 , 50 are transferred through electrical conduits EC and may be displayed at display screen 60 C, which is preferably an LCD type display. Alternatively, these results may be sent through a communication port 60 D such as an RS 232 port to another peripheral such as a remote computer. Control/display console 60 can also be equipped with an on-board dot-matrix printer 60 E. In addition, control/display console 60 includes a decoder chip adapted for decoding signal received from transducers, a CPU for performing calculations and other computing functions, a memory register, and other associated logic components and circuitry (not shown). A suitable decoder chip is a quadrature decoder available from HEWLETT PACKARD as model designation HCTL-2016. A suitable CPU is a micro controller unit available from PHILLIPS as model designation 87C52.
Centerline offset measurement device 40 is illustrated in more detail in FIGS. 3C and 4A through 4 D. Height measurement device 50 is illustrated in more detail in FIGS. 3B and 5A through 5 D.
Referring particularly to FIGS. 3C and 4A, centerline offset measurement device 40 includes a housing 42 , a lateral plunger 44 , and a horizontally-oriented sensor or transducer 46 (indicated schematically in FIG. 4A by phantom lines). Preferably, both lateral plunger 44 and transducer 46 are mounted within housing 42 . Lateral plunger 44 is movably mounted to housing 42 by conventional means, such that lateral plunger 44 can slide inwardly and outwardly with respect to housing 42 . An outer section 44 A of lateral plunger 44 extends outside housing 42 through a hole 42 A in a wall 42 B of housing 42 . Means such as a spring (not shown) is provided to interface with lateral plunger 44 and housing 42 and to impart a biasing force to lateral plunger 44 in a radially outward direction away from housing 42 . Preferably, an arrow-shaped plunger head 44 B is provided at a distal end 44 C of lateral plunger 44 for a purpose described hereinbelow. Means such as an electrical conduit EC containing lead wires is provided for transferring signals generated by transducer 46 .
Transducer 46 serves to measure a change in lateral position of lateral plunger 44 by converting a sense of the physical change in such position to an electronic signal representative of the magnitude of such change. For this purpose, transducer 46 is preferably an optical linear encoder module such as model designation HEDS 9200 R00 available from HEWLETT PACKARD. Transducer 46 operates in conjunction with a code strip (not shown) in a manner typical of optical encoders. Because transducer 46 is to measure positional changes of lateral plunger 44 , the code strip is mounted to an inner section 44 D of lateral plunger 44 in the vicinity of transducer 46 . Hence, as lateral plunger 44 moves, the code strip moves with respect to transducer 46 . As the code strip passes by transducer 46 , transducer 46 optically reads and counts lines on the code strip. The number of lines counted is correlated to a magnitude by which lateral plunger 44 has moved from an initial reference position. Alternatively, transducer 46 could be mounted to lateral plunger 44 and the code strip fixedly secured within housing 42 .
Referring to FIGS. 3C, 4 B and 4 C, a longitudinal recess 48 is formed in a rear face 42 C of housing 42 by a recess wall 48 A. Preferably, recess wall 48 A has a cylindrical profile to better accommodate the contour of shaft S. In an upper section 48 B of longitudinal recess 48 proximate to a top face 42 D of housing 42 , a clip-like member 49 is provided to assist the secure mounting of shaft centerline offset measurement device 40 to shaft S. Clip-like member 49 includes a pair of resilient prongs 49 A and 49 B. In addition, a bottom face 42 E of housing 42 may be configured to conform to the specific type of operative component, e.g., paddle or basket P, carried on shaft S in order to further assist in mounting thereto. Thus, in the exemplary embodiment shown in FIG. 4D, bottom face 42 E includes a groove 42 F that enables housing 42 to straddle paddle P when mounted to shaft S. FIGS. 6A and 6B show centerline offset measurement device 40 mounted to shaft S and shaft S installed in vessel V.
Referring particularly to FIGS. 3B and 5A, height measurement device 50 includes a housing 52 , a vertical plunger 54 , and a vertically-oriented sensor or transducer 56 (indicated schematically in FIG. 5A by phantom lines). As in the case of centerline offset measurement device 40 , both vertical plunger 54 and transducer 56 are preferably mounted within housing 52 . Vertical plunger 54 is movably mounted to housing 52 by conventional means, such that vertical plunger 54 can slide inwardly and outwardly with respect to housing 52 . An outer section 54 A of vertical plunger 54 extends outside housing 52 through a hole 52 A in a wall 52 B of housing 52 . Means such as a spring (not shown) is provided to interface with vertical plunger 54 and housing 52 and to impart a biasing force to vertical plunger 54 in a downward direction away from housing 52 . An end portion 54 B is attached to vertical plunger 54 in offset relation thereto by means of an intermediate member 54 C. Accordingly, when height measurement device 50 is mounted to shaft S, vertical plunger 54 is situated in parallel relation to shaft S and end portion 54 B is centrally disposed beneath shaft S and its operative component P. The purpose of end portion 54 B is described hereinbelow. Finally, means such as an electrical conduit EC containing lead wires is provided for transferring signals generated by transducer 56 .
In a manner analogous to that respecting centerline offset measurement device 40 , transducer 56 serves to measure a change in vertical position of vertical plunger 54 by converting a sense of the physical change in such position to an electronic signal representative of the magnitude of such change. Consequently, transducer 56 specified for height measurement device 50 is the same or similar unit as transducer 46 specified for centerline offset measurement device 40 , as well as the associated code strip which preferably is mounted to vertical plunger 54 .
Referring to FIGS. 3B, 5 B and 5 C, means are provided for mounting height measurement device 50 to shaft S similar to that respecting centerline offset measurement device 40 . That is, a longitudinal recess 58 is formed in a rear face 52 C of housing 52 by a cylindrically-profiled recess wall 58 A. A clip-like member 59 including a pair of resilient prongs 59 A and 59 B is disposed in an upper section 58 B of longitudinal recess 58 proximate to a top face 52 D of housing 52 . In addition, a bottom face 52 E of housing 52 includes a groove 52 F or other means for improving the securement of height measurement device 50 to shaft S provided with paddle P or the like, as shown in FIG. 5 D. FIGS. 7A and 7B show height measurement device 50 mounted to shaft S and shaft S installed in vessel V.
The operation of shaft centerline offset and height measurement system 30 will now be described with particular reference to FIGS. 3A, 6 A, 6 B, 7 A, 7 B, 8 A through 8 C, and 9 . By way of example, an indication of centerline offset is obtained before an indication of shaft or paddle height is obtained.
Referring to FIGS. 6A and 6B, the operation of centerline shaft measurement device 40 will first be described. Centerline offset measurement device 40 is affixed to shaft S. Shaft S is then lowered into vessel V at a normal operating position for shaft S. Because lateral plunger 44 is preferably biased radially outwardly, the tapered edges that comprise arrow-shaped plunger head 44 B assist in installing and removing shaft S from vessel V when centerline offset measurement device 40 is mounted to shaft S. After shaft S is disposed in its normal operating position, a distal end (which in the present exemplary embodiment corresponds to the outermost surface of plunger head 44 B) of outwardly biased lateral plunger 44 is in contact with a lateral inside surface ID of vessel V.
At this point, assuming shaft S is offset from the true central vertical axis of vessel V, lateral plunger 44 will have displaced laterally with respect to a zero reference position. At this plunger position, lateral plunger 44 will have displaced a distance equal to a displacement magnitude. This displacement magnitude is evident by the change in position of the code strip mounted to lateral plunger 44 . Transducer 46 encodes the displaced position of the code strip, and thus the displaced position of lateral plunger 44 , and sends the encoded signal to control/display console 60 (see FIG. 3 A), which decodes, stores, and processes the signal.
The displacement magnitude measured is one indication of the amount by which shaft S is offset from the central axis of vessel V. This displacement magnitude alone, however, is not necessarily a good indication when one considers that the position of lateral plunger 44 will change when lateral plunger 44 is disposed at other distal plunger positions on the circumference of lateral inside surface ID of vessel V. Accordingly, more precision can be achieved by employing transducer 46 to sample a plurality of displaced plunger positions. These displaced plunger positions are obtained when lateral plunger 44 is rotated to define a plurality of distal plunger positions located on the circumference of lateral inside surface ID. By doing so, a calculation of the centerline offset amount can be based on a plurality of displacement magnitudes measured by transducer 46 at different circumferential locations on lateral inside surface ID.
Referring to FIGS. 8A through 8C, lateral inside surface ID is assumed to be a perfect circle ABC for purposes of calculation and has a center O through which central axis of vessel V runs. The centerline of the shaft S is represented by a point T, thus illustrating that shaft S is clearly not in alignment with the central axis of vessel V. Shaft S with centerline offset measurement device 40 mounted thereto is inserted into vessel V as described above, at which time distal end or plunger head 44 B of lateral plunger 44 contacts lateral inside surface ID at a first distal plunger position A. The distance by which lateral plunger 44 is displaced at this time is encoded by transducer 46 and stored in control/display console 60 as a first displacement magnitude. After the first displacement magnitude is measured, second and third displacement magnitudes are likewise measured by respectively rotating lateral plunger 44 120° (or one-third of a revolution around lateral inside surface ID) to a second distal plunger position B and another 120° to a third distal plunger position C.
Lateral plunger 44 can be rotated by manually rotating housing 42 around shaft S or by rotating shaft S itself. In order to aid in locating the 120° positions, indicator marks (not shown) could be provided, for instance, on vessel centering ring CR (see FIG. 1 ). Nevertheless, the method described herein will give an accurate indication of centerline offset even if readings are taken at plunger positions that deviate approximately ±5° from the 120° positions.
Referring to FIG. 8A, a radial distance d 1 , along lateral plunger 44 from centerline T to first distal plunger position A, a radial distance d 2 along lateral plunger 44 from centerline T to second distal plunger position B, and a radial distance d 3 along lateral plunger 44 from centerline T to third distal plunger position C are obtained. Radial distances d 1 , d 2 and d 3 can be derived in a variety of ways, such as by taking a value representing some constant plunger length and adjusting that value by taking into account the measured first, second and third displacement magnitudes, respectively. A chordal distance AB between first and second distal plunger positions A, B, a chordal distance AC between first and third distal plunger positions A, C and a chordal distance BC between second and third distal plunger positions B, C are then calculated respectively according to the following equations derived from the law of cosines: AB = ( d 1 ) 2 + ( d 2 ) 2 - 2 · d 1 · d 2 · cos ( 2 · π 360 · 120 ) AC = ( d 1 ) 2 + ( d 3 ) 2 - 2 · d 1 · d 3 · cos ( 2 · π 360 · 120 ) BC = ( d 3 ) 2 + ( d 2 ) 2 - 2 · d 3 · d 2 · cos ( 2 · π 360 · 120 )
Next, a theoretical radius R for circle ABC based on chordal distances AB, AC, and BC is calculated according to the following equation: R = AB · AC · BC 4 · S · ( S - AB ) · ( S - AC ) · ( S - BC ) wherein factor S = AB + AC + BC 2
Referring to FIG. 8B, it follows that radius R is equal to a radius AO from center O to first distal plunger position A, a radius BO from center O to second distal plunger position B, and a radius CO from center O to third distal plunger position C. An angle AOB between radii AO and BO is then calculated according to the following equation derived from the law of cosines: AOB = cos - 1 ( ( AO ) 2 + ( BO ) 2 - ( AB ) 2 2 · AO · BO ) · 360 2 · π
Referring to FIG. 8C, values for radial distances AT and BT are equal to radial distances d 1 and d 2 , respectively. Thus, an angle ABT between radial distances AT and BT is calculated according to the following equation derived from the law of sines: ABT = sin - 1 ( d 1 · sin ( 120 · 2 · π 360 ) AB ) · 360 2 · π
Next, an angle ABO between chordal distance AB and radius BO and an angle OBT between radius BO and radial distance BT are calculated according to the following equations: ABO = 180 - AOB 2 OBT = ABT - ABO
It will be seen from FIG. 8C that a triangle is defined by three vertices corresponding to center O, centerline T, and second distal plunger position B. Because the values for two sides of this triangle, radius BO and radial distance BT, and the angle OBT therebetween are known, control/display console 60 can now calculate the value for the remaining side, which is the offset distance OT of centerline T from center O. Offset distance OT is calculated according to the following equation derived from the law of cosines: OT = ( BO ) 2 + ( d 2 ) 2 - ( 2 · BO · d 2 · cos ( OBT · 2 · π 360 ) )
The offset distance OT provides an accurate indication of the amount by which the centerline of shaft S is offset from the central axis of vessel V in any radial direction. This is because the calculation is based on three displacement magnitudes measured at three different positions of lateral plunger 44 within vessel V, and the relationships between the various points and distances observed within vessel V and described hereinabove can be resolved by trigonometric equations.
A preferred modification to the method described above yields the same result, i.e., calculation of offset distance OT, yet avoids the additional task of deriving values for radial distances AT, BT and CT from the first, second and third displacement magnitudes. In this preferred modification, advantage is taken of the fact that the first, second and third displacement magnitudes measured by transducer 46 are linearly proportional to radial distances AT, BT and CT, respectively. Thus, radial distance d 1 is set equal to zero, radial distance d 2 is set equal to a value based on the second displacement magnitude relative to the first displacement magnitude, and radial distance d 3 is set equal to a value based on the third displacement magnitude relative to the first displacement magnitude. For example, d 1 =0, d 2 =−0.1, and d 3 =−0.9. If such values for d 1 , d 2 and d 3 are used and the above equations applied, the same value for offset distance OT is obtained.
A further alternative method for calculating the amount by which the centerline of shaft S is offset from the central axis of vessel V will now be described with reference to FIG. 9 . Lateral inside surface ID of vessel V is represented by a circle AB in FIG. 9, and has a center O through which the central axis of vessel V runs. The centerline of shaft S is represented by point T. If a diameter for circle AB is drawn through center O and centerline T, it is observed that a maximum displacement magnitude will be measured when lateral plunger 44 is disposed within vessel V along a maximum radial distance AT, and a minimum displacement magnitude will be measured when lateral plunger 44 is rotated 180° and disposed along a minimum radial distance BT. If lateral inside surface ID of vessel V were a perfect circle, an offset distance OT could be found by subtracting radius AO from radial distance AT or by subtracting radial distance BT from radius BO. A preferred method of calculation, however, is derived as follows.
It is observed that maximum radial distance AT=AO+OT and minimum radial distance BT=BO−OT. For purposes of calculation, lateral inside surface ID of vessel V is assumed to be a perfect circle such that AO=BO. Thus, minimum radial distance BT=AO−OT. Offset distance OT can be found by subtracting maximum radial distance AT from minimum radial distance BT as follows:
AT−BT= ( AO+OT )−( AO−OT )=2 OT
Therefore, OT = ( AO + OT ) - ( AO - OT ) 2 = AT - BT 2
In order to implement this method, lateral plunger 44 is rotated 360°, i.e., one full revolution around the inside of vessel V. At predetermined intervals while lateral plunger 44 is rotating, e.g., every 5 ms, transducer 46 encodes the position of lateral plunger 44 to generate a data set consisting of a plurality of displacement magnitudes. From this data set, a maximum measured displacement magnitude d MAX and a minimum measured displacement magnitude d MIN are selected. An example of a subroutine that could perform this selection process can be constructed from the following steps:
1) READ a first displacement magnitude and STORE;
2) READ a second displacement magnitude and STORE;
3) IF second displacement magnitude<first displacement magnitude, THEN SET second displacement magnitude=d MIN AND SET first displacement magnitude=d MAX , ELSE SET second displacement magnitude=d MAX AND SET first displacement magnitude=d MIN ;
4) READ a third displacement magnitude;
5) IF third displacement magnitude<d MIN THEN SET third displacement magnitude=d MIN ;
6) IF third displacement magnitude>d MAX THEN SET third displacement magnitude=d MAX .
This procedure is repeated successively until each sampled displacement magnitude is determined to be either the maximum or minimum for the data set. Offset distance OT is then calculated according to the following equation: OT = d MAX - d MIN 2
Referring primarily to FIGS. 7A and 7B, the operation of height measurement device 50 will now be described. Height measurement device 50 is affixed to shaft S. Prior to installation of shaft S in vessel V, a spherical object such as a stainless steel ball 65 having a predetermined uniform diameter is placed into vessel V. Stainless steel ball 65 will come to rest at a lowermost point 19 on the inside surface of hemispherical end region 16 of vessel V, thereby locating the true bottom of vessel V. Vertical plunger 54 is biased to a fully downwardly extended position. In order to obtain a zero reference position, end portion 54 B of vertical plunger 54 is urged upwardly until good contact is made with the underside of paddle P or other operative component of shaft S. Shaft S is then inserted into vessel V at a normal operating position for shaft S.
Once shaft S has been installed, vertical plunger 54 moves downwardly until coming into contact with stainless steel ball 65 . At this point, vertical plunger 54 will have displaced vertically with respect to the zero reference position. The distance by which vertical plunger 54 displaces is characterized as its displacement magnitude. Transducer 56 encodes the displaced position by reading the code strip mounted to vertical plunger 54 and generates a signal representative of the measured displacement magnitude, in a manner analogous to the interaction of transducer 46 and the code strip of lateral plunger 44 of centerline offset measurement device 40 described hereinabove. Transducer 56 sends the encoded signal to control/display console 60 (see FIG. 3 A). The height of paddle P above lowermost point 19 of hemispherical end region 16 is most easily derived from the measured displacement magnitude by adding together the values for the displacement magnitude, the height of end portion 54 B and the diameter of stainless steel ball 65 .
As an alternative embodiment of the present invention, shaft centerline offset and height measurement system 30 can be modified to incorporate both the shaft centerline offset and height measurement functions in a single measurement device. That is, housing 42 or 52 can be adapted to accommodate both transducers 46 and 56 , plungers 44 and 54 , and their associated components described hereinabove. However, a preferred approach to this functional combination is to provide a more modular device which does not require the mounting of a single (and bulkier and heavier) housing to shaft S.
This preferred alternative embodiment will now be described with reference to FIGS. 10A, 10 B, 11 A, 11 B and 12 , illustrating a combined shaft centerline offset and height measurement device generally designated 70 .
Instead of employing a housing to serve as a mounting assembly for centralizing the operative components of the present embodiment, a modified vessel centering ring 75 is provided. Modified vessel centering ring 75 includes a central region 75 A having a bore 75 B through which shaft S with paddle P or the like can be inserted.
Combined shaft centerline offset and height measurement device 70 includes a centerline offset measurement module generally designated 80 and a height measurement module generally designated 90 . It will be noted that all operative components of combined shaft centerline and offset measuring device 70 , including centerline offset measurement module 80 and a height measurement module 90 , are mounted directly or indirectly to modified vessel centering ring 75 , and thus operate independently of shaft S. Thus, while only one centerline offset measurement module 80 could be provided and rotated by means such as a turntable mounted to modified vessel centering ring 75 , it is more advantageous to provide three centerline offset measurement modules 80 , all of which are suspended from modified vessel centering ring 75 independently of shaft S. Moreover, as shown in FIGS. 10A and 10B, centerline offset measurement modules 80 are oriented 120° from each other, thereby eliminating the alignment and rotation steps attending centerline offset measurement device 40 in FIGS. 4A through 4D.
Referring to FIGS. 11A and 11B, each centerline offset measuring module 80 includes a sensor body 82 which serves as a mounting bracket for a lateral plunger 84 and a transducer 86 . Sensor body 82 preferably has a U-shaped profile defined by a central region 82 A and legs 82 B and 82 C. Transducer 86 is preferably secured directly to the inside of leg 82 B of sensor body 82 , and preferably is an optical linear encoder similar to transducers 46 and 56 . An upper linear bearing 102 A is attached to a top surface 82 D of central region 82 A and a lower linear bearing 104 A is attached to an end 82 E of leg 82 C. A lower bearing track 104 B is attached to each lateral plunger 84 and engages lower linear bearing 104 A, thereby enabling lateral plunger 84 to slide laterally with respect to sensor body 82 . A code strip 106 is fixedly secured to lateral plunger 84 to cooperate with transducer 86 in the manner described hereinabove.
As shown in FIG. 10B, three upper bearing tracks 102 B (of which only two are shown) are attached to central region 75 A of modified vessel centering ring 75 . Upper linear bearing 102 A of each sensor body 82 engages a corresponding upper bearing track 102 B to enable each sensor body 82 to slide laterally with respect to modified vessel centering ring 75 . In the exemplary embodiment shown in FIGS. 10A and 10B, means such as springs (not shown) are provided respectively for biasing each lateral plunger 84 radially inwardly and for biasing each sensor body 82 radially outwardly. Thus, when shaft S is installed into vessel V, plunger tips 84 A of lateral plungers 84 are biased to contact shaft S while rear faces 82 F of sensor bodies 82 are biased to contact lateral inside surface ID of vessel V. Each lateral plunger 84 has upper and lower guide members 84 B and 84 C, respectively, to assist in urging lateral plungers 84 outwardly when shaft S is being inserted and removed from vessel V.
FIG. 12 is a detailed view of height measurement module 90 , which is an alternative to incorporating the structure of height measurement device 50 described hereinabove. Height measurement module 90 includes a sensor mounting bracket 92 , a vertical plunger 94 , and a vertically-oriented transducer 96 . Vertical plunger 94 preferably includes a vertical rail 94 A, an upper arm 94 B, and a lower arm 94 C. Sensor mounting bracket 92 includes a clamping section 92 A by which sensor mounting bracket 92 is fixedly secured to vertical rail 94 A, such as by inserting vertical rail 94 A through clamping section 92 A and tightening clamping section 92 A with a fastener (not shown) threaded into holes 92 B.
In the preferred embodiment, lower arm 94 C includes an arcuate section 94 CA and a lower end portion 94 CB extending horizontally from arcuate section 94 CA. Likewise, upper arm 94 B includes an arcuate section 94 BA and a lower end portion 94 BB extending horizontally from arcuate section 94 BA. Arcuate sections 94 BA and 94 CA are disposed adjacent to each other, and upper end portion 94 BB is disposed above lower end portion 94 CB. Means such as a spring 98 is connected between upper end portion 94 BB and lower end portion 94 CB in order to vertically bias upper and lower end 94 BB and 94 CB portions away from each other.
Lower arm 94 C is secured to sensor mounting bracket 92 , or preferably is secured directly to vertical arm 94 A such as by inserting vertical arm 94 A into an upper portion of lower arm 94 CC and employing fastening means similar to clamping section 92 A. Upper arm 94 B is mounted to an annular bearing 99 through which vertical rail 94 A extends, thus enabling upper arm 94 B to move vertically with respect to lower arm 94 C and transducer 96 . Vertical rail 94 A is provided with a longitudinal groove 94 A′ which engages a complementary tongue (not shown) disposed within annular bearing 99 , thereby preventing annular bearing 99 and upper arm 94 B from rotating around vertical rail 94 A. Upper arm 94 B includes a recessed area 94 BC into which a code strip (not shown) is attached to cooperate with transducer 96 .
Vertical rail 94 A is movably attached to modified vessel centering ring 75 in order to render combined shaft centerline offset and height measurement device 70 compatible with vessels V of different sizes. Preferably, an annular bearing (not shown) similar to annular bearing 99 is attached to modified vessel centering ring 75 and vertical rail 94 A is extended therethrough. In addition, means such as a spring (not shown) is provided to bias vertical rail 94 A (and thus height measurement module 90 in its entirety) downwardly.
To complete the measurement system, it will be readily apparent that combined shaft centerline and offset measurement device 70 is operable in conjunction with control/display console 60 in FIG. 3A, although some reprogramming is necessary. Combined shaft centerline and offset measurement device 70 can be made to communicate with control/display console 60 by running appropriate data lines such as conduits EC from transducers 86 , 96 to control/display console 60 .
The operation of combined shaft centerline and offset measurement device 70 will now be described. Stainless steel ball 65 is inserted into vessel V in order to locate lowermost point 19 of hemispherical end region 16 . Modified vessel centering ring 75 , equipped with combined shaft centerline and offset measurement device 70 , is then fitted onto rack 18 of dissolution testing station DTS over one of vessels V. At this time, rear face 82 F of radially outwardly biased sensor body 82 of each centerline offset measurement module 80 makes contact with lateral inside surface ID of vessel V. Additionally, lower end portion 94 CB of downwardly biased vertical plunger 94 of height measurement module 90 makes contact with stainless steel ball 65 .
Shaft S is then lowered into vessel V to its normal operating position. Shaft S passes through bore 75 B of modified vessel centering ring 75 while being lowered into vessel V. Also, paddle P contacts one or more upper guide members 84 B of lateral plungers 84 while shaft S is being lowered into vessel V, thus urging one or more of lateral plungers 84 outwardly to clear the way for paddle P to pass downwardly. Once shaft S reaches its normal operating position, plunger tips 84 A of radially inwardly biased lateral plungers 84 are in full contact with shaft S.
Assuming shaft S is offset from the central axis of vessel V, one or more of lateral plungers 84 of centerline offset measurement modules 80 will have displaced outwardly with respect to a predetermined zero reference position for displaced lateral plunger or plungers 84 . Hence, lateral plungers 84 operate in a manner analogous to lateral plunger 44 of centerline offset measurement device 40 . Each lateral plunger 84 if displaced will have moved by a distance equal to a displacement magnitude along the radial direction of that particular lateral plunger 84 . This physical event is measured and converted into an electrical signal by the coaction of transducer 86 and its associated code strip 106 as described hereinabove. Accordingly, three signals representing the displacement magnitudes at the 120° positions along lateral inside surface ID of vessel V are sent to control/display console 60 . Offset distance OT is then preferably calculated by employing the sequence of steps including the trigonometric equations described hereinabove.
Height measurement module 90 also operates when shaft S is installed in vessel V. Before the bottom end of shaft S or its paddle P reaches its lowermost position within vessel V, upper end portion 94 BB of upper arm 94 B of vertical plunger 94 is biased in its highest position above lower end portion 94 CB of lower arm 94 C. This constitutes a zero reference position for vertical plunger 94 . As shaft S is being lowered into vessel V, paddle P makes contact with upper end portion 94 BB. By the time shaft S reaches its final, normal operating position, paddle P will have urged upper end portion 94 BB downwardly towards lower end portion 94 CB against the biasing force of spring 98 . As the code strip for vertical plunger 94 is fixedly mounted in recessed area 94 BC of upper arm 94 B, the code strip moves downwardly by the same distance as upper end portion 94 BB. This distance constitutes the displacement magnitude for vertical plunger 94 , which is encoded by transducer 96 , and a signal is sent to control/display console 60 for further processing. One way to derive or interpret the height of paddle P above lowermost point 19 of vessel V is to add together values for the measured displacement magnitude, the height of upper end portion 94 BB, the height of lower end portion 94 CB, and the diameter of stainless steel ball 65 .
It will be understood that while the Figures depict control/display console 60 as being portable and designed for remote operation, the present invention encompasses a variation wherein control/display console 60 is integrated into dissolution testing station DTS. For example, the operative components of control/display console 60 can be housed within programmable systems control module 20 of dissolution testing station DTS (see FIG. 2 ).
FIGS. 13A and 13B illustrate by way of example a flow diagram of a test routine executable by software written for control/display console 60 . The particular test routine illustrated manages the operation of shaft centerline offset and height measurement system 30 with centerline offset measurement device 40 and height measurement device 50 . It will be understood, however, that the software can be rewritten without undue experimentation and adapted for use of control/display console 60 with combined shaft centerline offset and height measurement device 70 . It is also to be noted that this test routine can be configured, for example, to test up to 30 dissolution testing stations DTS and up to 8 shafts S and corresponding vessels V per dissolution testing station DTS. Therefore, a total of 240 shaft sites can be tested in a single test routine if desired.
Referring again to FIGS. 13A and 13B, display screen 60 C of control/display console 60 displays a main menu at step 115 , prompting the user to select either a test run for shaft height measurement or a test run for shaft offset measurement. If the user selects a test run for shaft height measurement, a shaft height measurement subroutine 120 - 137 is initiated. On the other hand, if the user selects a test run for shaft offset (or “ctr line”) measurement, a shaft offset measurement subroutine 140 - 157 is initiated.
When the shaft height measurement subroutine is initiated, the user is prompted at step 120 to assign an integer from 1 to 30 to the dissolution testing station presently being tested in order to distinguish that testing station from other testing stations to be tested. The user is then prompted at step 125 to input an identification for that particular testing station, such as a serial number. Shafts operating in that testing station are assigned numbers according to the respective positions of the shafts in the testing station, such as 1 through 6 or 1 through 8. Thus, the user is prompted at step 130 to either initiate testing of a particular shaft, proceed to the next shaft, or exit the shaft height measurement subroutine and return to the main menu.
If the user desires to test that particular shaft, the user is prompted at step 131 to input an identification for the shaft, such as a serial number. Next, the user is prompted at step 132 to input an identification for the vessel in which the shaft operates. The user is then prompted to place the stainless steel ball into the vessel at step 133 , install the shaft height measurement device at step 134 , press the vertical plunger upwardly against the paddle or basket of the shaft in order to obtain a zero reference reading at step 135 , and lower the shaft equipped with the height measurement device into the vessel at step 136 . Once the shaft height measurement has been taken and appropriately interpreted, a readout or indication of the shaft height is displayed at step 137 and the user is prompted to test another shaft in the particular testing station being tested.
When the shaft centerline offset measurement subroutine is initiated by selection at step 115 , the user is prompted at step 140 to assign an integer to the dissolution testing station presently being tested. The user is then prompted at step 145 to input an identification for that particular testing station. Next, the user is prompted at step 150 to either initiate testing of a particular shaft identified by its position number, proceed to the next shaft, or exit the shaft centerline offset measurement subroutine and return to the main menu.
If the user desires to test that particular shaft, the user is prompted at step 151 to input an identification for the shaft. Next, the user is prompted at step 152 to input an identification for the vessel in which the shaft operates. The user is then prompted to install the shaft centerline offset measurement device at step 153 , and to lower the shaft equipped with the offset measurement device into the vessel at step 154 . After a key input is entered at this position, the user is prompted at step 155 to rotate the shaft 120°. A key input is requested to indicate the completion of this step. The user is then prompted at step 156 to rotate the shaft another 120°, and a key input is requested to indicate the completion of this step. Once the measurements taken at these positions have been appropriately interpreted and the offset distance calculated, a readout or indication of the shaft centerline offset is displayed at step 157 and the user is prompted to test another shaft in the particular testing station being tested.
These steps are repeated for every shaft and dissolution testing station desired by the user to be tested.
It will be understood that in the case where the centerline offset is measured by making one full rotation around the vessel in order to sample a plurality of displacements, the steps of the test routine are modified accordingly. It will also be understood that in the case where a testing routine such as that just described is adapted for use in conjunction with combined shaft centerline offset and height measurement device 70 , the total number of steps required by the test routine can be reduced.
It will be further understood that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation—the invention being defined by the claims.
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Apparatus and methods for measuring the amount by which the centerline of a shaft disposed in a vessel is offset from the central vertical axis of the vessel, and for measuring the height of such shaft above the inside bottom of the vessel. Apparatus includes a shaft centerline offset measurement device, a shaft height measurement device, and a control/display console. Each measurement device includes a transducer or optical encoder for sensing a displaced position of a biased plunger to which a code strip is mounted. The devices may be combined into a single shaft offset and height measurement device. Improved methods include calculating shaft offset based on a plurality of readings from the transducer, and applying trigonometric relationships. The apparatus and methods are particularly useful in the verification of paddle or basket shafts utilized in dissolution testing stations, so that the dissolution testing protocol complies with government agency guidelines.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 10/130,864 filed on Nov. 4, 2002. This application claims the benefit and priority of PCT/US00/24943, filed Sep. 12, 2000. This application claims the benefit of U.S. Provisional Application No. 60/167,887 filed Nov. 26, 1999. The entire disclosure of each of the above applications are incorporated herein by reference.
GOVERNMENT LICENSE RIGHTS
This invention was made with Government support under 9752985 awarded by The National Science Foundation. The Government has certain rights in the invention.
FIELD OF THE INVENTION
This invention relates to a system and method for interactive, adaptive, customized and individualized computer-assisted instruction of students, preferably implemented on network connected computers. More particularly, the system and method comprises i) an assembly tool for bringing diverse educational resources together to create customized course material for the instruction of students and ii) a replication element to update each resource and assure access to each updated resource. The system and method of the present invention responds to the instructor's creativity, allowing the instructor to shape and control the instructional materials and process.
BACKGROUND OF THE INVENTION
The application of computers in education has been limited by several problems, including a) a failure to provide systems that adapt to new advances in course material caused by technological developments, b) a failure to permit customized design of instructional information by the teacher, and c) a failure to integrate systems effectively into the existing curriculum.
Current approaches merely sequence students through pre-packaged educational materials. These systems do not provide any means for gathering or using more comprehensive information from outside sources. Consequently, the educational materials are relatively static and outdated, resulting in course of limited to poor quality.
Computer assisted instruction systems have ignored or under-utilized such important developments in computer technology in recent years as client-server systems and networking systems. Though now an active field with a wide spectrum of activities from research to commercial applications, application of dynamic on-line systems in educational, instructional, and homework tasks is only just starting to be explored.
What is needed is a computer-driven system that adapts to new information, allows for new information to be readily utilized by an instructor, so that the instructor can integrate new information into the existing curriculum.
SUMMARY OF THE INVENTION
The present invention contemplates a system and method for computer-assisted education, comprising a Resource Assembly Tool (RAT) and a Dynamic Resource Replication (DRR) element. The RAT provides a graphical user interface inside of a standard web browser. The interface consists of a plurality (e.g. two or more) browser windows. In one embodiment, a first browser widow is configured as resizable with a frameset that contains the menu and the map under construction, and a second multipurpose non-resizable window that displays information and input forms. Once a new map is started, the author can then enlarge the map area and insert resources into it. These resources may be identified by URL or simple network browsing or searching metadata sources. Once resources have been located they are connected together using the link mode of the RAT.
Rather complex maps can be generated using the RAT. These are different from binary trees, both because branches can loop back, and because branches can be re-united. Additionally, maps that are not created by the RAT are accessible by the RAT with the resultant generation of a graphical layout of the map. The RAT then provides the integration of several maps, thus creating nested maps. A course can easily contain several hundred of these nested maps. Due to the inherent complexity of this arrangement all maps and conditions are compiled into a pre-processed binary data structure at the start of a session.
The delivery system for these resources consists of a distributed network of servers. While each author has a so-called home server which holds the authoritative copy of all resources published by that author, all servers in the network can host sessions utilizing these resources. DRR is designed to prevent overload situations on any one server in the network, as well as to avoid single points of failure in the network. Replication processes between servers in the network are triggered in two situations: i) a user wants to retrieve a resource from a server in the network which is not locally present on that server; ii) an author publishes a new version of a resource. In the first case, after localizing the author's home server and a series of authentication steps, the session-hosting server subscribes to the resource and replicates it to a local copy. In the latter case, all subscribed servers are notified that a new version is present, and according to a decision algorithm either replicate the new version or unsubscribe from it.
As the RAT allows an author to assemble resources from across the network into consistent presentations, the DRR mechanism was found to be capable of ensuring the integrity of such presentations even if parts of the network are down, inaccessible or overloaded. The dynamic nature of the DRR allows for just-in-time just-enough replication of resources and thus is different from caches, which are not updated when a resource changes, and static replication mechanisms implemented in many databases which only allow for non-discriminate replication of predefined chunks of data at prespecified times.
The characteristics of the DRR allow extremely large server networks to operate together without risk of a network failure. The selective replication capability of the DRR of the specific file requested by RAT limits the required memory, transmission time, and does not require the users computer to interact with the complete database of the Library server.
Thus, the present invention contemplates, in one embodiment, a method of combining educational resources, comprising: a) providing i) a network comprising a first home server of a first educational institution and a second home server of a second educational institution, said first home server hosting (i.e. holding in memory or in otherwise in a database) a first pool of resources, said second home server hosting to a second pool of resources, said resources comprising combinable fragments, pages, sequences and courses, ii) a first author at said first educational institution and a second author at said second educational institution, iii) a resource assembly tool configured for use by said first and second authors; and b) accessing a resource (e.g. a fragment, page, sequence, portion of a course, or entire course) from said second pool of resources through the actions of said first author; c) combining, through the use of said resource assembly tool by said first author, said resource from said second pool of resources with a resource (again, a fragment, page, sequence of pages, portion of a course, or entire course) from said first pool of resources. In a preferred embodiment, said accessing comprises replicating said resource from said second pool of resources.
It is not intended that the present invention be limited to the combination of resources “as is.” The author has the freedom to make changes to the fragments, pages, sequences, courses and the like having educational content. For example, prior to said combining, the present invention contemplates that said first author modifies said resource of said second pool of resources (the original resource is not overwritten; rather a new version is created). On the other hand, prior to said combining, said first author may modify said resource of said first pool of resources. Of course, said first author may also choose to modify both resources before combining.
The present invention contemplates that, in one embodiment, said combining is part of the process for creating a first page, said page comprising combined resource fragments. It is not intended. however, that the present invention be limited to pages having only two fragments. In other words, the combining of first and second fragments may be preceeded—or followed—by combinations of other fragments. In some cases, the combining is the last step in the creation of a first author page.
It is also not intended that the combining only be at the fragment level. Resources can be combined to create entire courses. For example, a sequence of pages can be combined with another sequence to make a course.
As noted in more detail below, the present invention contemplates that said first author publishes said first author combination (e.g. page, sequence of pages, or course), thereby adding said first author combination to said first and second pools of resources. In other words, the product of the combining is made accessible to authors from other institutions, so that they may use the new product “as is” or as subsequently modified. For example, the first author page may be accessed by said second author and said second author, after said accessing, is free to modify said first author page so as to create a second author page.
It is not intended that the second author be limited to the nature or extent of modifications. The second author may choose to delete or edit material on the page. On the other hand, the second author may choose to add additional fragments, pages, etc. from one or more pools of resources. In any event, the present invention contemplates that said second author, after said accessing and modifying, publishes said second author combination (e.g. page or other resource), thereby adding said second author combination to said first and second pool of resources.
In other words, the sharing can continue because—whatever the second author does to the material—it is available to the first author for possible use, as well as any other authors that are part of the system via the network. Indeed, it is not intended that the number of institutions or authors be limited in any way. Instances where three or more institutions are involved are contemplated. For example, the present invention contemplates in one embodiment a method of combining educational resources, comprising: a) providing i) a network comprising a first home server of a first educational institution, a second home server of a second educational institution, and a third home server of a third educational institution, said first home server hosting a first pool of resources, said second home server hosting a second pool of resources, and said third home server hosting a third pool of resources, said resources comprising combinable fragments, pages, sequences of pages, and courses, ii) a first author at said first educational institution and a second author at said second educational institution, iii) a resource assembly tool configured for use by said first and second authors; and b) accessing, through the actions of said first author, i) a resource (e.g. fragment, page, etc.) from said second pool of resources and ii) a resource from said third pool of resources; c) combining, through the use of said resource assembly tool by said first author, said resource from said second pool of resources and said resource from said third pool of resources to create a first combination.
In the above-described embodiment, said first author is using and combining material from third-party sources. However, it is not intended that the present invention limit the author as to where resources can be obtained. Moreover, the author can combine in any manner desired. For example, the method can further comprise d) combining a resource (e.g. a fragment, page, etc.) from said first pool of resources with said first combination to create a second combination.
All of the above-described discussion about replicating as part of accessing can apply to the three (or more) institution embodiment. Similarly, the freedom to modify prior to combining should again be underscored. Most importantly, the present invention contemplates that said first author publishes said first author page, thereby adding said first author page to said first, second and third pools of resources, and thereby permitting access by other authors (who may make further changes and combinations to create a second author page).
A variety of system configurations can carry out the methods described above. In one embodiment, the present invention contemplates a system for sharing educational resources, comprising: a) a first author computer at a first educational institution connected to a first home server, said first author computer having a user interface, said first home server providing access to a first pool of resources comprising combinable resources (e.g. fragments, pages, sequences of pages, portions of courses, and entire courses); b) a second author computer at a second educational institution connected to a second home server, said second author computer having a user interface, said second home server providing access to a second pool of resources comprising combinable resources; c) a network connecting said first home server of said first educational institution to said second home server of said second educational institution; d) a resource assembly tool configured for use through said user interface of said first and second author computers, said resource assembly tool capable of combining said combinable resources from said first pool of resources and said second pool of resources; and e) a resource replication element configured so as to replicate resources from said first and second pools of resources prior to said combining of said resource assembly tool. Importantly, the systems are not limited to the number of servers or client computers.
DESCRIPTIONS OF THE DRAWINGS
FIG. 1 provides a top level schematic of the primary interfaces of the LearningOnline Network.
FIG. 2A shows the overview of network communication links between servers of the LearningOnline Network.
FIG. 2B shows an example of the Hosts Lookup Table.
FIG. 2C illustrates the response times of server-server communications without disk access.
FIG. 2D illustrates the response times of server-server communications with disk access.
FIG. 3A depicts the implementation of the Dynamic Resource Replication.
FIG. 3B describes the process of modifying a resource.
FIG. 4 shows a top level illustration of the Resource Assembly Tool.
FIG. 5A presents an embodiment of a graphical user interface during Resource Assembly Tool access.
FIG. 5B presents an example of the graphical user interface during Resource Assembly Tool access.
FIG. 5C presents another example of the graphical user interface during Resource Assembly Tool access.
FIG. 6 shows the non-graphical (XML) presentation of FIG. 5C .
FIG. 7A shows an example of a course map having nested sequences.
FIG. 7B shows an example of a course map sequence having nested pages.
FIG. 7C shows an example of a course map summary sequence.
FIG. 8 shows an example of a flow chart during a course initialization first run.
FIG. 9A illustrates an example of a flow chart during a course initialization first run for the procedure loadmap.
FIG. 9B demonstrates an example of a resource properties hash dump resulting from the loadmap procedure.
FIG. 9C demonstrates an example of a resource properties hash dump resulting from the links between resources from the loadmap procedure.
FIG. 9D demonstrates an example of a resource properties hash dump resulting from the links and link conditions between resources from the loadmap procedure.
FIG. 10 depicts an example of an excerpt of the dump of the condition array constructed in the loadmap procedure.
FIG. 11A illustrates an example of a flow chart during a course initialization first run for the procedure traceroute.
FIG. 11B depicts an example of an excerpt of the resource properties hash dump resulting from cumulative link conditions to reach a certain resource.
GENERAL DESCRIPTION OF THE INVENTION
Current computer-assisted instructional systems have only haphazardly exploited the potential of client-server systems and networking technologies. The present inventors recognize that systems, running under sophisticated windowing operating systems, can support advanced object based software applications, including high speed graphics, animation and audio output, that are particularly suited to education. Servers can store gigabytes of educationally relevant data and programs at central or distributed locations at quite reasonable cost.
Clients and servers can be linked remotely with increasing convenience and decreasing cost. The Internet has emerged as a means of providing an inexpensive means of connecting computers to provide effective communications and access to information and other resources such as software. Further Internet developments that made the Internet truly universal include the HTML and the HTTP protocols, which provide platform independent access to hyperlinked multimedia information, and the Java™ programming language, which provides platform independent software for Internet applications programming. Subsets of the Internet (called intranets) have become an increasingly important means for disseminating information and enabling communication within constrained domains, such as a single school system or corporate enterprise.
The present invention provides the tools for management and control over the computer-assisted instruction materials and provides the needed flexibility to allow an instructor to construct customized material using information from diverse educational resources. The present invention provides the tools for the integration of traditional educational material (such as data, equations and the like) from several sources. More importantly, the present invention permits an instructor to select from a wider and richer variety of educationally relevant sound and visual display objects. All elements of the on-screen display can be pulled from diverse sources and synthesized in an integrated display calling for graphics, animation, video, or sound as appropriate. The present invention provides the authoring tools needed to generate multimedia educational course material presentations that is accessible to the on-line student.
The elements of the display objects can be created by people other than the actual instructor (e.g. third-party teachers, artists, animators, singers and so forth). The instructor, through the tools of the present invention, has access to these materials and can utilize all or a portion of a third-party's course materials in the assembly of a customized on-line course, lecture, class, or session. The educational resources are stored in libraries (e.g. as data snips or dynamic clip art) and then accessed by the instructor in an implementation of this invention. These educational resources can be in the form of short clips of text, sound, voice, graphics, animation or video. Using the resource assembly tool of the present invention, these diverse resources can be combined according to the desires and creativity of the instructor to generate a customized presentation.
Another important object is that the method and system of this invention is adapted to implementation on a variety of networks. When so implemented, the interactive, adaptive, and self-paced computer-assisted instruction and homework provided by this invention is available to geographically dispersed students and from geographically dispersed schools.
The network on which this invention is implemented can be configured as an intranet. In another embodiment, implementation is achieved over the public Internet. In either case, the system is configured with appropriate links and is compatible with browser and e-mail format extensions. In short, this invention is adaptable to Network Computers (“NC”). NCs are low cost computers specifically designed to access intranets or the public Internet. In a current preferred embodiment and implementation, this invention is adaptable to multimedia PCs for some students or students with special needs. Typical interactive devices include keyboards, mice or other pointing devices, voice recognition, joy-sticks, touch activated devices, light-pens, and so forth. Other devices, such as virtual reality devices, can be added as they become commercialized.
Authoring instructional materials for a course, lecture, class or other type of educational presentation to a student, when done according to the method of the present invention, typically comprises several steps, including decisions about the objects to display to the student and the sequencing of these objects. The first step is the selection of objects which carry the education content for presentation to a student. Objects can include visual display items, such as text, animation or movies, audible display items, such as voice, audio and so forth. They can include input items known in the computer arts, such as buttons to select. Selections to chose from include (but are not limited to) the text to enter, the useful hypertext and hypermedia links, and functions to perform with student input and so forth. The second step is the selection of the sequencing logic for the ordered display of the objects to the student throughout the course, lecture, class or session.
Importantly, to increase the utility of the materials, the number of hard-coded hyperlinks between the resources should be minimized. The actual combining and sequencing is part of the system functionality and driven by RAT-constructed ‘roadmaps’, which are constructed by the instructors. With this mechanism, one and the same resource can be part of different courses in different contexts.
The present invention contemplates the use of algorithms in the design of the student interface virtual course resources. In one embodiment, the learner is provided with multiple representations of the same knowledge elements and can select a preferred representation. In a preferred embodiment, algorithms that learn from a learner's previous selection of preferred options are employed and these automatically customize the course to the learners' needs, offering remedial actions for detected shortcomings and allowing leaps over segments of material for which the student is predicted to already have achieved mastery.
The present invention contemplates an automated exam engine that will produce randomized and/or individualized tests without the instructor having the need or even the opportunity to select the problems. This can be done by providing a large pool of exam questions via an open source database. Each exam problem contains attached metadata that catalogs its degree of difficulty and discrimination for students of different ability levels.
Using the RAT, an instructor can create and/or assemble a customized set of assignments, quizzes, and examinations with a large variety of conceptual questions and quantitative problems. These on-line presentations can include pictures, animations, graphics, tables, links, etc. The writing and development is facilitated by numerous types of individualized problems designed to encourage students to collaborate and discuss concepts while insuring that problems differ for each student to inhibit rote copying.
Indeed, the present invention contemplates a feedback system i) where students and other instructors can comment, criticize, evaluate and/or grade a resource, and ii) where the author of the resource can comment, evaluate, grade and/or assist with performance of the student. With regard to the latter, in a preferred embodiment, students are given instant feedback and relevant hints via the Internet and may correct errors without penalty prior to an assignment's due date. The system keeps track of student's participation and performance, and records are available in real time both to the instructor and to the individual student. Statistical tools and graphical displays facilitate assessment and course administration.
This invention contemplates the ability of this student feedback system to be initiated by a screen button on the student's navigation graphical interface that opens up a text field. When the student sends a feedback, it arrives at an email address (or set of email addresses) specified by the course faculty; independent of the computer platform. With the normal ‘reply’ function, faculty or teaching assistants can respond to the student input and the reply automatically is returned by handling within the network. This type of student input improves the use of the on-line resources. For example, if additional specific hints are included in the reply by the instructor, these changes take effect within the network immediately and all students benefit.
Also contemplated by this invention is a chatroom that allows for multiple ways of communication. Learners can post text, graphics, whiteboard information and formulas into the chatroom, which operates without any plugins.
With regard to students and other instructors commenting and grading resources, the present invention contemplates compiling feedback of this type in an electronic file associated with the particular resource (whether the resource is a fragment, page, sequence of pages, portion of a course, or entire course). When the author of the resource (or another instructor) accesses the resource, the cumulative feedback associated with the particular resource (at that time) is available for review (e.g. the author or other instructor can query the feedback) so that comments and criticism can be considered in any effort to edit/modify the resource, thereby improving the resource. This process is an on-going process, allowing for the possibility of continuous improvement of the resource as it is experience by students or utilized by other instructors. By virtue of the feedback system, resources can be placed in competition. That is to say, students can apply a grade (or a set of grades directed to various features of a resource such as clarity, technical functionality, accuracy and the like) to a particular resource (e.g. a fragment, page, sequence of pages, portion of a course, or course) and that grade can be compared to the grade given to another resource in the same field (e.g. biology, math, etc.). If desired, the resource receiving the higher grade (or the higher average grade based on cumulative grading from a plurality of students) can thereafter be selected preferrentially for instructional purposes.
Thus, the present invention also contemplates a method of evaluating educational resources, comprising: a) providing i) a network comprising a first home server of a first educational institution and a second home server of a second educational institution, said first home server hosting a first pool of resources, said second home server hosting a second pool of resources, said resources comprising combinable fragments, pages, sequences and courses, ii) a first author at said first educational institution and a second author at said second educational institution, iii) a resource assembly tool configured for use by said first and second authors; iv) one or more students connected through one or more computers to said network, said computers having a user interface; b) displaying a resource from said first pool of resources through the actions of a student on said user interface of said student's computer, to create a first displayed resource; c) grading said first displayed resource, whereby a numerical value associated with said first displayed resource is stored in a file; and d) accessing said first displayed resource (whether or not the resource is currently displayed or otherwise in use) through the actions of said first author, under conditions such that said numerical value associated with said first displayed resource is apparent to said author. Of course, the process need not stop here. In one embodiment, the present invention further contemplates, e) combining, through the use of said resource assembly tool by said first author, a resource from said first or second pool of resources with said displayed resource under conditions wherein said displayed resource is modified to create a modified first displayed resource; f) displaying said modified first displayed resource through the actions of a student on said user interface to create a second displayed resource; g) grading said second displayed resource, whereby a numerical value associated with said second displayed resource is stored in a file; and h) accessing said second displayed resource (whether or not the resource is currently displayed or otherwise in use) through the actions of said first author, under conditions such that said numerical value associated with said second displayed resource is apparent to said author. In some cases, the numerical value associated with the second displayed resource will be higher than the numerical value associated with the first displayed resource, indicating that [at least according to the student(s)] the resource has been improved. Again, the process need not stop here; indeed, the above indicated steps can be repeated numerous times (in the manner of a feedback loop).
The present invention is not limited to grading from students. The above-indicated method steps can be modified such that other instructors provide the feedback and the grading.
In addition, the present invention is not limited to grading and numerical values. The above-indicated method steps can be modified such that written comments or other symbols are provided as feedback in association with a resource.
Furthermore, the present invention is not limited to review of feedback and use of feedback by the original author. The above-indicated method steps can be modified such that a second author at another institution views the feedback and modifies the resource accordingly.
A. The Resource Assembly Tool
The RAT generates pathways that link resources. The RAT acts as a graphical user interface inside of a standard web browser. This invention contemplates that any browser-compatible software language will support RAT's function. The RAT/browers interface in one embodiment comprises two or more windows. For example, one window is resizable, and the other is a multipurpose non-resizable window. The former window contains the menu and the current project, while the latter window displays general operational information. When a new project is started the default settings are limited to start and finish codes, thus allowing the user complete freedom of choice for the resource links.
The project window operates in a similar manner as most popular computer operating systems. Editing is accomplished by using the mouse to click on the appropriate resource, or in the alternative, a dialog box allows use of describing the title of the resource for retrieval through the network. The dialog boxes also accept URL addresses that are either part of the institutions intranet or an external WWW URL. The invention contemplates an ability for the user to access a central database directory to search for and/or browse to locate desired resources.
The dialog box may also be utilized to delete resources from a linked pathway as well as adding them. It is envisioned that an option of a complete severance from the integrated pathway is coupled with an alternative options of merely removing the specific resource and leaving the pathway intact.
Once a desired resource is located, the link mode of the RAT is utilized. This function “physically” connects on resource to another that is the basis of the basic inventive concept of this system.
The default mode of the RAT is info mode. This allows the user to quickly pan the mouse over the presented pathway to examine the metadata of each resource. For example, if the mouse pointer is stopped over a movie resource, an information bubble will appear that presents the title, actors, subject matter, and running time. This will allow an instructor to quickly assess whether any particular pathway requires modification for a new course or due to changes within a specific academic field. If the instructor does require changes to the resource they only click on the resource and the RAT enters edit mode, thus allowing changes.
B. The Replication Element
To enable immediate and dynamic system reconfiguration in case of server or network downtimes and overload situations, data replication is required, where any machine in the network can serve any learner in the institution. On approach is to use a server network of inexpensive web servers running Linux® and the Apache web server, which communicate with each other via persistent TCP connections. The network of the present invention has the ability to replicate resources and update user records dynamically from server to server, as well as the ability to transfer user sessions between each other in overload situtations.
In order for the resource pool to be functionally more consistent and comprehensive, all resources in one embodiment take the form of a multimedia object and are stored in the multimedia resource pool. For each content author, the system will provide separate private construction and public resource space. Moving a resource from construction space into the public resource pool is combined with the ‘wizard’-assisted gathering of abstracts, classification information and keywords (IMS compliant metadata and the Library of Congress classification scheme), as well as versioning and access privilege scheme.
C. Other System Elements
This invention contemplates the integration of the Computer-Assisted Personalized Approach (CAPA) with the other system elements in order to provide students with personalized problem sets, quizzes and exams. Different students see slightly different problems, which enables them to collaborate on a conceptual level without being able to blindly copy answers. Students are given instant feedback and relevant hints via the Internet and may correct errors without penalty until the assignment due date. The system records the students' participation and performance, and the records are available online to both the instructor and the individual student.
CAPA is a teaching tool, not a curriculum, and as such does not dictate course design, content or goals. Instead, it enables faculty to augment their courses with individualized relevant exercises. CAPA, as a stand-alone system has been widely accepted by more than 40,000 students in astronomy, biochemistry, chemistry, mathematics, physics, botany, accelerator physics, and a host of human ecology and computer science courses since 1992. CAPA has been licensed by various institutions for instruction in several disciplines.
This invention contemplates an integrated embodiment of CAPA with the LearningOnline Network (LON-CAPA). This linkage implements an infrastructure that allows a group of organizations (departments, universities, colleges, and commercial businesses) to link their on-line learning communities. LON-CAPA thus enables institutions to share their on-line learning objects and act as a common marketplace.
Most current on-line homework engines are close to faculty needs and desires but due to time and budget constraints they lack scalability and failover security. Systems that provide on-line homework are frequently subject to strong peak workloads close to deadlines, while at the same time their functionality is crucial.
The LON-CAPA is a distributed system with a classical three-tier architecture based on a communication backbone. The nodes in the network can be geographically distributed among different departments and even institutions with only the commodity Internet as link.
LON-CAPA is based on a network of basic computers as access servers and a few high-performance library servers. While library servers hold all objects (content and system) of a subset of users within the network anytime, access servers act as intelligent caches and replicate the needed resources at that point upon demand and update them as becomes necessary.
Definitions
The terms “instructional materials” or “educational materials” encompass all educational resources used as components of a course of instruction, or as components of a lecture, class, or other type of session with one or more students.
The terms “educational resource” or simply “resource” indicate an elementary piece or “fragment” of text, sound, voice, graphics, animation, and/or video (e.g. in the form of data snips or clip art) that can be combined, utilizing the Resource Assembly Tool (RAT) of the present invention, to represent a complete on-screen presentation (e.g. whether a single screen or “page of fragments” or whether a plurality of pages and links). With RAT, fragments can be combined into “pages” (i.e. something that a browser would display as a page or a printer would print as a page). Pages can be combined into sequences, and sequences into courses. Such components are selected according to the course (physics, math, biology, etc.) and can include prerequisite tests, pretests, lessons, and unit tests.
A “network” is the hardware and software connecting student client computers to school servers. “Network connections” can comprise fiber optic links, wired links or terrestrial or satellite wireless links. Servers are linked together on the network. There are “home” servers for each resource “author.” A first resource author can, using the Resource Assembly Tool of the present invention, access a resource on his/her own home server; alternatively, a first resource author can also access a resource on a second resource author's home server.
Teachers and other instructional designers can create, or “author,” materials for use in this invention (teachers are thus “authors”). Materials can be original or can be derived from existing textbooks, workbooks or media material. They can simply employ elements of standardized curricula, pretests such as criterion tests, post-tests, and standardized texts. However, the present invention is particularly suited to non-standardized curricula and the use of on-line educational resources authored by third-parties collaborating in a combined educational effort.
Parties collarborating in a combined educational effort can be from a variety of “educational institutions” including but not limited to public and private colleges and universities.
To encourage resource sharing and “re-usage” and to improve the quality of the educational resources, teachers and other instructional designers should be able to modify (“edit”) the resources for their own use, or even be ‘value adders’. Modifying and adding value to a resource allows all parties collaborating and contributing to the resource library to share and generate improved and enhanced instructional materials. It should be stressed that “modifying” is meant to indicate the creation of a new derivative resource of branch (while preserving the original resource in its original form). In other words, the modified resource does not override the a resource; rather it creates a new resource in the system which is derived from the orginal resource. In a preferred embodiment, a detailed log is kept with all branches of a resource specifying authorship history in machine-readable form.
Efficient re-usage of educational objects only works if those objects can actually be found in the potentially large pool of resources. The present invention contemplates that an instructor can “query” for an image with a graphical representation of particular information form a particular topic (e.g. trigonometry, calculus, etc.).
The present invention contemplates “personalized homework” or “individualized homework.” This means that each student sees a slightly different computer-generated problem. This encourages collaboration between students on a conceptual level, but prevent blind copying of answers. The students get immediate automatic feedback for their entered homework answers, while faculty are able to provide answer-specific hints for common problems identified either beforehand or during the class term.
The term “httpd” is used to indicate Hypertext Transfer Protocol Daemon, a detached permanent server process that serves web content.
The term “GIF” refers to a Graphical Interface Format, a common format for INternet graphics developed by Compuserve.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment of the system and method of the present invention, the Network comprises of relatively inexpensive upper-PC-class server machines which are linked through the commodity interne in a load-balancing, dynamically content-replicating and failover-secure way. FIG. 1 schematically shows an overview of this network. All machines in the Network are connected with each other through two-way persistent TCP/IP connections. Clients (B, F, G and H in FIG. 1 ) connect to the servers via standard HTTP. There are two classes of servers, Library Servers (A and E in FIG. 1 ) and Access Servers (C, D, I and J in FIG. 1 ). Library Servers are used to store all personal records of a set of users, and are responsible for their initial authentication when a session is opened on any server in the Network. For Authors. Library Servers also host their construction area and the authoritative copy of the current and previous versions of every resource that was published by that author. Library servers can be used as backups to host sessions when all access servers in the Network are overloaded. Otherwise, for learners, access servers, are used to host the sessions. Library servers need to be strong on I/O, while access servers can generally be cheaper hardware. The network is designed so that the number of concurrent sessions can be increased over a wide range by simply adding additional Access Servers before having to add additional Library Servers. Preliminary tests showed that a Library Server could handle up to 10 Access Servers fully parallel.
The Network is divided into so-called domains, which are logical boundaries between participating institutions. These domains can be used to limit the flow of personal user information across the network, set access privileges and enforce royalty schemes.
Example of Transactions
FIG. 1 also depicts examples for several kinds of transactions conducted across the Network. An instructor at client B modifies and publishes a resource on her Home Server A. Server A has a record of all server machines currently subscribed to this resource, and replicates it to servers D and I. However, server D is currently offline, so the update notification gets buffered on A until D comes online again. Servers C and J are currently not subscribed to this resource. Learners F and G have open sessions on server I, and the new resource is immediately available to them. Learner H tries to connect to server I for a new session, however, the machine is not reachable, so he connects to another Access Server J instead. This server currently does not have all necessary resources locally present to host learner H, but subscribes to them and replicates them as they are accessed by H.
Learner H solves a problem on server J. Library Server E is H's Home Server, so this information gets forwarded to E, where the records of H are updated.
Transaction Mechanism
FIG. 2 elaborates on the details of this network infrastructure. FIG. 2A depicts three servers (A, B and C) and a client who has a session on server C. As C accesses different resources in the system, different handlers, which are incorporated as modules into the child processes of the web server software, process these requests.
Our current implementation uses mod_per 1 inside of the Apache web server software. As an example, server C currently has four active web server software child processes. The chain of handlers dealing with a certain resource is determined by both the server content resource area (see below) and the MIME type, which in turn is determined by the URL extension. For most URL structures, both an authentication handler and a content handler are registered.
Handlers use a common library lonnet to interact with both locally present temporary session data and data across the server network. For example, lonnet provides routines for finding the home server of a user, finding the server with the lowest load average (loadavg), sending simple command-reply sequences, and sending critical messages such as a homework completion, etc. For a non-critical message, the routines reply with a simple “connection lost” if the message could not be delivered. For critical messages, lonnet tries to reestablish connections and re-send the command. If no valid reply could be received, it answers “connection deferred” and stores the message in buffer space to be sent at a later point in time. Also, failed critical messages are logged.
The interface between lonnet and the Network is established by a multiplexed UNIX domain socket (denoted DS in FIG. 2A ). The rationale behind this rather involved architecture is that httpd processes (Apache children) dynamically come and go on the timescale of minutes, based on workload and number of processed requests. Over the lifetime of an httpd child, however, it has to establish several hundred connections to several different servers in the Network.
On the other hand, establishing a TCP/IP connection is resource consuming for both ends of the line, and to optimize this connectivity between different servers, connections in the Network are designed to be persistent on the timescale of months, until either end is rebooted. This mechanism will be elaborated on below.
Establishing a connection to a UNIX domain socket is far less resource consuming than the establishing of a TCP/IP connection. lonc is a proxy daemon that forks off a child for every server in the Network. Which servers are members of the Network is determined by a lookup table, of which FIG. 2B is an example. In order, these entries denote: an internal name for the server, the domain of the server, the type of the server, the host name, and the IP address.
The lonc parent process maintains the population and listens for signals to restart or shutdown, as well as USR 1 . Every child establishes a multiplexed UNIX domain socket for its server and opens a TCP/IP connection to the lond daemon (discussed below) on the remote machine, which it keeps alive. If the connection is interrupted, the child dies, whereupon the parent makes several attempts to fork another child for that server.
When starting a new child (a new connection), first an init-sequence is carried out, which includes receiving the information from the remote lond which is needed to establish the 128-bit encryption key; the key is different for every connection. Next, any buffered (i.e., delayed) messages for the server are sent.
In normal operation, the child listens to the UNIX socket, forwards requests to the TCP connection, gets the reply from lond, and sends it back to the UNIX socket. Also, lonc takes care of the encryption and decryption of messages. lonc was built by putting a non-forking multiplexed UNIX domain socket server into a framework that forks a TCP/IP client for every remote lond.
lond is the remote end of the TCP/IP connection and acts as a remote command processor. It receives commands, executes them, and sends replies. In normal operation, a lonc child is constantly connected to a dedicated lond child on the remote server, and the same is true vice versa (two persistent connections per server combination).
lond listens to a TCP/IP port (denoted P in FIG. 2A ) and forks off enough child processes to have one for each other server in the network plus two spare children. The parent process maintains the population and listens for signals to restart or shutdown. Client servers are authenticated by IP.
When a new client server comes on-line, lond sends a signal USR 1 to lonc, whereupon lonc tries again to reestablish all lost connections, even if it had given up on them before a new client connecting could mean that that machine came on-line again after an interruption.
The gray boxes in FIG. 2A denote the entities involved in an example transaction of the Network. The Client is logged into server C, while server B is her Home Server. Server C can be an Access Server or a Library Server, while server B is a Library Server. Client submits a solution to a homework problem, which is processed by the appropriate handler for the MIME type “problem”. Through lonnet, the handler writes information about this transaction to the local session data. To make a permanent log entry, lonnet establishes a connection to the UNIX domain socket for server B. lonc receives this command, encrypts it, and sends it through the persistent TCP/IP connection to the TCP/IP port of the remote lond. lond decrypts the command, executes it by writing to the permanent user data files of the client, and sends back a reply regarding the success of the operation. If the operation was unsuccessful, or the connection would have broken down, lonc would write the command into a FIFO buffer stack to be sent again later. lonc now sends a reply regarding the overall success of the operation to lonnet via the UNIX domain port, which is eventually received back by the handler.
Scalability and Performance Analysis
The scalability was tested in a test bed of servers between different physical network segments and FIG. 2B shows the network configuration of this test. In the first test, the simple ping command was used. The pinging command is used to test connections and yields the server short name as reply. In this scenario, lonc was expected to be the speed-determining step, since lond at the remote end does not need any disk access to reply. The graph in FIG. 2C shows the number of seconds until completion versus the number of processes issuing 10,000 ping commands each against one Library Server (a 450 MHz Pentium II was used in this test, with a single IDE HD). For the solid dots, the processes were concurrently started on the same Access Server and the time was measured until the processes finished—all processes finished at the same time. One Access Server, the 233 MHz Pentium II, can process about 150 pings per second, and as expected, the total time grows linearly with the number of pings.
The gray dots were taken with up to seven processes concurrently running on different machines and pinging the same server—the processes ran fully concurrent, and each process finished as if the other ones were not present (about 1000 pings per second). Execution was fully parallel.
In a second test, lond was the speed-determining step—10,000 put commands each were issued first from up to seven concurrent processes on the same machine, and then from up to seven processes on different machines. The put command requires data to be written to the permanent record of the user on the remote server.
In particular, one “put” request meant that the process on the Access Server would connect to the UNIX domain socket dedicated to the library server, lonc would take the data from there, shuffle it through the persistent TCP connection. lond on the remote library server would take the data, write to disk (both to a dbm-file and to a flat-text transaction history file), answer “ok”, lonc would take that reply and send it to the domain socket, the process would read it from there and close the domain-socket connection.
The graph in FIG. 2D shows the results of the above test. Series 1 (solid black diamond) is the result of concurrent processes on the same server—all of these are handled by the same server-dedicated lond-child, which lets the total amount of time grow linearly. Series 2 through 8 were obtained from running the processes on different Access Servers against one Library Server, each series goes with one server. In this experiment, the processes did not finish at the same time, which most likely is due to disk-caching on the Library Server—lond-children whose datafile was (partly) in disk cache finished earlier. With seven processes from seven different servers, the operation took 255 seconds till the last process was finished for 70,000 put commands (270 per second)—versus 530 seconds if the processes ran on the same server (130 per second).
Server Content Resource Areas
Internally, all resources are identified primarily by their URL. Different logical areas of the server are distinguished by the beginning part of the URL:
/adm: publicly available content, logos, manual pages, etc. /res/domainname/authorname/ . . . : the resource area, holding course maps, HTML pages, homework, movies, applets, etc. Access to these files is restricted by the cookie-based authentication mechanism. Content in this area will be served by type-dependent handlers, for example, one handlers to serve homework problems, and another one for TeX resources. The structure of this area of the server is exactly the same on every server, even though not all resources might be present everywhere. /raw/domainname/authorname/ . . . : internally, this is just a symbolic link to the res directory, however, no content handlers are called when serving a resource and access is controlled by IP rather than cookies. This structure is used for replication of resources between servers. /˜authorname/ . . . : the content construction space. This is normal UNIX filespace, which however can only by viewed on the web by the authors themselves through the cookie-based authentication. Content handlers are active for this space. This space can be mounted on other UNIX machines, as well as AppleShare and Windows. Below the authorname, this directory has the same structure as the resource space of the author.
Publication of a Resource
Authors can only write-access the /˜authorname/ space. They can copy resources into the resource area through the publication step, and move them back through a recover step. Authors do not have direct write-access to their resource space. During the publication step, several events will be triggered. Metadata is gathered, where a wizard manages default entries on a hierarchical per-directory base. The wizard imports the metadata (including access privileges and royalty information) from the most recent published resource in the current directory, and if that is not available, from the next directory above, etc. The Network keeps all previous versions of a resource and makes them available by an explicit version number, which is inserted between the file name and extension, for example foo.2.html, while the most recent version does not carry a version number (e.g., foo.html). Servers subscribing to a changed resource are notified that a new version is available.
Dynamic Resource Replication
Since resources are assembled into higher order resources simply by reference, in principle it would be sufficient to retrieve them from the respective Home Servers of the authors. However, there are several problems with this simple approach. Since the resource assembly mechanism is designed to facilitate content assembly from a large number of widely distributed sources, individual sessions would depend on a large number of machines and network connections to be available, and thus be rather fragile. Also, frequently accessed resources could potentially drive individual machines in the network into overload situations.
Finally, since most resources depend on content handlers on the Access Servers to be served to a client within the session context, the raw source would first have to be transferred across the Network from the respective Library Server to the Access Server, processed there, and then transferred on to the client.
To enable resource assembly in a reliable and scalable way, a dynamic resource replication scheme was developed. FIG. 3 shows the details of this mechanism. Anytime a resource out of the resource space is requested, a handler routine is called which in turn calls the replication routine ( FIG. 3A ). As a first step, this routine determines whether or not the resource is currently in replication transfer ( FIG. 3A , Step D 1 a ). During replication transfer, the incoming data is stored in a temporary file, and Step D 1 a checks for the presence of that file. If transfer of a resource is actively going on, the controlling handler receives an error message, waits for a few seconds, and then calls the replication routine again. If the resource is still in transfer, the client will receive the message “Service currently not available.”.
In the next step ( FIG. 3A , Step D 1 b ), the replication routine checks if the URL is locally present. If it is, the replication routine returns “OK” to the controlling handler, which in turn passes the request on to the next handler in the chain.
If the resource is not locally present, the Home Server of the resource author (as extracted from the URL) is determined ( FIG. 3A , Step D 2 ). This is done by contacting all library servers in the author's domain (as determined from the Lookup Table, see FIG. 2B ). In Step D 2 b , a query is sent to the remote server whether or not it is the Home Server of the author (in our current implementation, an additional cache is used to store already identified Home Servers (not shown in the figure)). In Step D 2 c , the remote server answers the query with “True” or “False”. If the Home Server was found, the routine continues, otherwise it contacts the next server (Step D 2 a ). If no server could be found, a “File not Found” error message is issued. In our current implementation, in this step the Home Server is also written into a cache for faster access if resources by the same author are needed again (not shown in the figure).
In Step D 3 a , the routine sends a subscribe command for the URL to the Home Server of the author. The Home Server first determines if the resource is present, and if the access privileges allow it to be copied to the requesting server ( FIG. 3A , Step D 3 b ). If this is true, the requesting server is added to the list of subscribed servers for that resource (Step D 3 c ). The Home Server will reply with either “OK” or an error message, which is determined in Step D 4 . If the remote resource was not present, the error message “File not Found” will be passed on to the client. If the access was not allowed, the error message “Access Denied” is passed on. If the operation succeeded, the requesting server sends an HTTP request for the resource out of the /raw server content resource area of the Home Server.
The Home Server will then check if the requesting server is part of the network, and if it is subscribed to the resource (Step D 5 b ). If it is, it will send the resource via HTTP to the requesting server without any processing by content handlers (Step D 5 c ). The requesting server will store the incoming data in a temporary data file (Step D 5 a ); the same file checked in Step D 1 . If the transfer is not completed, and appropriate error message is sent to the client (Step D 6 ). Otherwise, the transferred temporary file is renamed as the actual resource, and the replication routine returns “OK” to the controlling handler (Step D 7 ).
FIG. 3B depicts the process of modifying a resource. When an author publishes a new version of a resource, the Home Server will contact every server currently subscribed to the resource ( FIG. 3B , Step U 1 ), as determined from the list of subscribed servers for the resource generated in FIG. 3A , Step D 3 c . The subscribing servers will receive and acknowledge the update message (Step U 1 c ). The update mechanism finishes when the last subscribed server has been contacted (messages to unreachable servers are buffered). Each subscribing server will check if the resource in question had been accessed recently, that is, within a configurable amount of time (Step U 2 ).
If the resource had not been accessed recently, the local copy of the resource is deleted (Step U 3 a ) and an unsubscribe command is sent to the Home Server (Step U 3 b ). The Home Server will check if the server had indeed originally subscribed to the resource (Step U 3 c ) and then delete the server from the list of subscribed servers for the resource (Step U 3 d ). If the resource had been accessed recently, the modified resource will be copied over using the same mechanism as in Step D 5 a through D 7 of FIG. 3A ( FIG. 3B , Steps U 4 a through U 6 ).
Construction of a Course by the Instructor
Content Re-usage and Granularity
Any faculty participating in the Network can publish their own learning resources into the common pool. To that end, the Network provides a “construction space” which is only accessible to the author, and a publication process, which transfers the material to the shared pool. During the publication process, metadata about the resource is gathered, and system-wide update notification and versioning mechanisms are triggered.
Learning resources can be simple paragraphs of text, movies, applets, individualizing homework problems, etc. In addition to providing a distributed digital library with mechanisms to store and catalog these resources, the Network enables faculty to combine and sequence these resources at several levels. An instructor from Community College A could combine a text paragraph from University B with a movie from College C and an online homework problem from Publisher D, to form one page. Another instructor from High School E can take that page from Community College A and combine it with other pages into a module, unit or chapter. Those in turn can be combined into whole coursepacks. Faculty can design their own curricula from existing and newly created resources instead of having to buy a complete off-the-shelf product.
FIG. 4 shows a general overview of the resource assembly mechanism and the different levels of content granularity supported by the current implementation of this principle. The topmost puzzle piece represents a resource at the fragment level—one image, one movie, one paragraph of text, one problem, or one regular web page. Attached to the resource is metadata gathered at the publication time of the resource.
Using the resource assembly tool described below, these fragments and pages can be assembled into a page. A page is a resource of the grain size which would be rendered as one page on the web and/or on the printer.
Using the same tool, fragments (which would then be rendered as stand-alone pages), pages, and sequences can be assembled into sequences. Sequences are resources which are rendered a sequence of pages, not necessarily linear. Examples are one lesson, one chapter, or one learning cycle.
On the third granularity level, fragments (rendered as stand-alone pages), pages, and sequences can be assembled into courses. Courses are a sequence which represents the entirety of the resources belonging to a learning unit into which learners can be enrolled. Examples are a University one-semester course, a workshop, or a High School class.
Maps
To increase the utility of the materials, the number of hard-coded hyperlinks between the resources should be minimized. The actual combining and sequencing is part of the system functionality and driven by RAT-constructed “roadmaps”, which are constructed by the instructors. With this mechanism, one and the same resource can be part of different courses in different contexts. The soft-linking makes it possible to import only the desired set of resources without effectively importing additional parts another instructors resources through hard-linked menus or “next page” buttons that might resided on those resources.
Curriculum Adaptivity
Maps allow for conditional choices and branching points. The actual path through and presentation of the learning resources is determined by instructor-specified combinations of learner choices and system generated adaptations (for example, if the learner does not pass a test, additional resources may be included). Each learner can have an individualized curriculum according to preferences, capabilities and skills.
These maps can be generated at different levels of granularity with a graphical tool, or in an automated way through custom scripts.
Resource Assembly Tool
The Network provides the Resource Assembly Tool as one means to generate maps. The Resource Assembly Tool provides a graphical user interface inside of a standard web browser. The current implementation is written in JavaScript™. FIG. 5 shows screenshots of the current implementation. The interface usually consists of two browser windows, one resizable one with a frameset that contains the menu and the map under construction, and a multipurpose non-resizable window that displays information and input forms. When a new map is started, it only has a start and a finish resources. The author can then enlarge the map area and insert resources into it.
In FIG. 5A , the author is editing information about a resource in the map after clicking on the box representing the resource in the map. In the dialog, the author can enter a map-internal title for the resource, which is displayed to the learners when navigating the maps. In the same dialog, the author will specify the URL of the resource, which can either be internal to the Network, or any URL of a web page outside of it. For internal resources, the author can also browse the Network filesystem or search the resource metadata to locate an appropriate resource.
The resource priority can be chosen. A resource can be “regular.” “mandatory” or “optional.” These resource priorities are only used in the bookkeeping of earned points by the learners. Within the map, resources of different priorities are displayed in different colors. The dialog also allows for two modes of removing the resource from the map: either deleting it from the map including every link to and from it, or deleting it while reconnecting any links that went through the resource. As an example, resources A and B might both connect to resource C, and resource C might connect to D. When removing C from the map using the first option, both A and B will not no longer be connected to D. Using the second option, both A and B will reconnect with D. In the latter case, the Resource Assembly Tool will also handle conditional links correctly: such as, if A connected to C under condition 1 , and C connected to D under condition 2 , then in the end A will connect to D under a new condition which is ( 1 AND 2 ).
Finally, this dialog allows the author to connect the resource to another resource (or itself) through a new link. When selecting this option, the Resource Assembly Tool goes into link mode, and will link the current resource to the next clicked resource (unless the action is cancelled).
FIG. 5B shows the Resource Assembly Tool in info mode, that is, when no specific component of the map is edited, and if the Tool is not in link mode. In info mode, the contents of the dialog window change dynamically as the mouse is moved over the components of the map. In this case, the mouse pointer is over the link condition between two resources. The dialog window shows the titles of the connected resources, as well as the condition priority. In this scenario, the condition priority is set such that the link cannot be taken (i.e., “is blocked”) if the condition is false. The condition priority can also be set such that the link is recommended if the condition is true (possibly giving the learner several options where to go next), or that the link must be taken (“is forced”) over any other possible link if the condition is true. Within the map, conditions of different priorities are displayed in different colors. If the author now were to click on the condition, the Tool would go into edit mode, and the condition could be edited.
FIG. 5C shows the Tool in edit mode for the link between the resource titles displayed. The author can remove the link, or insert a new resource into the link. Obviously, by this mechanism, rather complex maps can be generated. These are different from binary trees, both because branches can loop back, and because branches can be re-united. In fact, most branches re-unite in the finish resources. Into each link, a condition with one of three different priorities can be attached. Whether or not a certain resource in the map can be displayed depends on whether or not it can be reached through any path along allowed links, starting with the start resource of the course. If a resource is not linked to, it is assumed to be accessible if the map which it is part of is accessible.
Map Representation and Storage Format
FIG. 6 shows the XML representation of the resource map constructed in FIG. 5 , which is the format in which maps are stored. In the figure, however, additional graphical map layout information generated by the Resource Assembly Tool is not displayed. This graphical information is optional to re-generate the same graphical layout when the map is brought up again in the Resource Assembly Tool, and is not needed for any other system functionality.
Maps can be generated by tools other than the Resource Assembly Tool. In particular, an author might have some other representation of a course sequence, which can be converted into a map using scripts. If this map then were to be brought up in the Resource Assembly Tool, the Tool would automatically generate a graphical layout for it. Each entry of the map, resources, conditions and links, are stored in separate tags.
Resources and conditions have to have unique ID numbers. These numbers are automatically generated by the Resource Assembly Tool when the entry is first created, or added to the entries when a map generated outside the Resource Assembly Tool is first retrieved. They can also be assigned by custom scripts or added in by hand.
In this example, FIG. 6 , entry 1 is the start resource of the map. When this map is accessed, the source (src) URL of this tag will be the first resource rendered. Entry 2 is the finish resource of this map. This resource will be the last resource in the sequence of resources. Entry 6 is a problem resource with the given URL and title, as well as the priority “mandatory”. Entry 19 is a condition, which is used by the link between entries 6 , the problem, and 9 , a sequence.
Example of Nested Maps
FIG. 7 shows the XML representation of three maps which are imported into each other. FIG. 7B is the sequence that is referenced as resource 9 in the course map FIG. 7A . In the resulting map, the entry point of resource 9 in FIG. 7A is in fact the entry point of the start resource of FIG. 7B , namely, resource 1 . The exit point of resource 9 in FIG. 7A is the exit point of the finish resource of FIG. 7B , namely, resource 2 . FIG. 7C is the page which is referenced as resource 24 in FIG. 7B .
A course can easily contain several hundreds of these nested maps. Since the accessibility of each individual resource in the course depends on the state of all possible paths linking it to the start resource of the course across all intermediate maps, the computation and disk-I/O effort per single transaction could quickly become prohibitive. Thus, all maps and conditions are compiled into a pre-processed binary data structure at the start of a session.
Initialization of a Course for a Learner
When a learner first enters a course during a session, the system will initialize this course for the learner. In particular, at this point, the course map and all nested (embedded) maps and resources are evaluated, and the information is compiled into two binary structures, which are stored with the session information: the resource properties hash, and the link conditions array. This information will be used over the duration of the session for several purposes: navigation (which resource is the next, which one the previous?), for access control (can the resource be reached under the link conditions given the current state of the student?), and to register assessment results within the context of a certain course and map (there might be several instances of the same problem resource within a course).
Evaluation of the Map Structure for a Course
The URL of the course is passed to the procedure readmap ( FIG. 8 ). Procedure readmap first initializes the resource properties as an empty hash, seeds the link conditions array with a 0th element, which is set to “true”, priority “normal”, and sets the map counter to 0 ( FIG. 8 , Step R 1 ). While the resource properties hash, the link conditions array and the map counter are global variable of the initialization process, all other variables are local to the procedures (an important property for these routines to run recursively). The procedure readmap then calls procedure loadmap for the URL of the course ( FIG. 8 . Step R 2 ).
FIGS. 9 & 10 show a dump of excerpts of the binary structure generated in loadmap for the nested maps of FIG. 7 . Procedure loadmap ( FIG. 9A ) first checks if the map URL has already been processed (multiple inclusion of the same map in a course structure) ( FIG. 9A , Step L 1 ). If the URL was processed, it has been assigned a map counter value in the resource properties hash. If the map has been processed, there is no need to process it again, and loadmap returns.
If the map has not been processed, the map counter is incremented and the map is registered under the current value in the resource properties hash ( FIG. 9A , Step L 2 ). The file is then opened ( FIG. 9A , Step L 3 ), which might entail prior replication, and the contents are parsed. If there are no further entries, loadmap returns ( FIG. 9A . Step L 4 ).
The new entry tag is then read ( FIG. 9A . Step L 5 ) and the type is determined ( FIG. 9A , Step L 6 ). If the entry is a resource (Step L 7 ), a resource ID is formed by combining the map counter and the resource ID within the map. For example, the “Part 1 Introduction” resource of part 1 .sequence ( FIG. 7B ) was assigned the resource ID 2 . 5 , since it has the internal resource ID 5 in the 2 nd map processed (see FIG. 9B under “ids_”). If the same URL is found again, additional IDs are assigned to it. It is necessary to store the IDs under the URL in the resource properties hash for reverse lookup if a user simply requests a URL. If the resource is a start or finish resource, the resource ID is registered as the start or finish resource of the map, respectively ( FIG. 9B . “map—start”. “map_finish”). The properties of the resource (URL, Title, Priority, etc) are now stored under the resource ID (see for example FIG. 9B “title_ 2 . 5 ”).
If the resource is not a map itself ( FIG. 9A , Step L 8 ), the next entry is read. Otherwise, procedure loadmap calls itself recursively to process that map (Step L 9 ). If in Step L 6 , the type of the entry was determined to be a condition. a condition ID is formed (Step L 10 ) by again combining the map counter with the internal ID. The condition is also added to the end of the condition array (see FIG. 10 ), which is a compilation of all conditions in the course (Step L 11 ). The conditions in this array are evaluated when a transaction occurs that could change the state of the student, and the state of each condition is stored by the index number in the session environment. A reference to the index number in the condition array is stored under the condition ID ( FIG. 9D . “condid_”).
If the entry is a link (Step L 6 ), a link ID is generated (Step L 121 . This ID is formed by combining the map counter and another counter which is incremented for every new link within the map. Under this ID, the IDs of the originating and the destination resource of the link are stored, as well as that of the link condition ( FIG. 9D ). For the originating resource, in Step L 13 the link ID is added to the list of outgoing links ( FIG. 9C , “to_”), and for the destination resource, the link ID is added to the list of incoming links ( FIG. 9C , “from_”).
After the last entry has been processed, procedure loadmap returns. After the last map has been processed, the original course-level instance of loadmap returns to readmap ( FIG. 8 , Step R 2 ). The next major step will be to determine all possible paths and conditions leading up to a resource for access control.
readmap checks if the course has a start resource from its map_start entry in the resource properties (Step R 2 ), and if does not, continue to store the two global binary data structures (Steps R 5 , R 6 ). In this special case, all resources which are part of any maps in the course are assumed to be accessible.
If the course has a start resource, readmap calls the procedure traceroute ( FIG. 11A ) with the following parameters (Step R 4 ); 1) the cumulative condition along this path or route so far is set to “true” (the map is accessible). 2) the resource ID of the start resource of the course map, and 3) an empty list for all resources processed so far along this route. It is again important to note that all variables except the global binary structures are local to traceroute, since traceroute will recursively call itself whenever there is a branching to follow all possible paths of the maps.
traceroute will establish a section within the resource properties hash that builds up all conditions leading up to a resource. FIG. 11B shows an excerpt of the final result. For example, resource 2 . 5 , the introduction to part 1 , can be reached under condition 8 (see FIG. 10 ), meaning, after solving the pretest problem. traceroute first checks if the resource has already been processed on this route by its resource ID ( FIG. 11A . Step T 1 ). This test avoids that traceroute runs into endless loops when the links on the map loop. Next, the resource ID is added to the list of processed resources on this route (Step T 2 ).
The resource conditions are now OR'd (i.e. a logical “or” is appled) with the cumulative conditions on this route (Step T 3 )—the route represents another way of getting to the resource. A small routine with simplification rules for boolean expressions is called to simplify the potentially very long expression.
In the next step, it is determined if the resource is itself a map (Step T 4 ). If it is, the exit route conditions can differ from the entry route condition by all additional conditions along the paths in the embedded maps (for non-map resources, entry and exit route conditions are the same). If, however, the embedded map does not have a start resource (Step T 5 ), that is not the case—again, the missing of entry point to an embedded link structure is interpreted as the resources being openly accessible.
If the embedded map does have a start resource. traceroute is called recursively with the current route conditions, the ID of the start resource of that map, and the list of already processed resource IDs (Step T 6 ). Upon return, if the embedded map does not have a finish resource, the entry and exit conditions of this map are assumed to be the same (Step T 7 ). If the map had a finish resource, the route condition so far is set to the resource condition of the finish resource of the embedded map (Step T 8 ). In order go on from here, the user would have had to reach the finish resource of the embedded map.
Now the route conditions are correctly set for exiting the resource and going on from here. traceroute now loops over all outgoing links of the resource (Step T 9 ). If the link does have a link condition (Step T 10 ), then the route condition for this branch path is the cumulative route condition so far AND the link condition (Step T 1 I). If there is no link condition, then there is no change in route conditions (Step T 12 ). To further process the routes along this link, traceroute is called recursively with the resource ID of the destination resource of the link, the new route conditions, and the list of already processed resources (Step T 13 ). traceroute returns after processing the last outgoing link of the resource it had been called.
FIG. 11B shows part of the output of traceroute for the example FIG. 7 .
Multivalued Boolean Evaluation of Link Priorities
When a user accessed a resource on a map and desires to access the “next” resource, the request is processed by a number of steps. From the data exemplified in FIG. 9C , it is determined which outgoing links exist. From the data in FIG. 9D it is determined to which resources those links lead. For each of the resources, the expressions in FIG. 11A are evaluated as follows. Stored in the session environment is the evaluation of the table FIG. 10 , where the boolean part is evaluated as “0” or “1”. In addition, a multivalued boolean value is computed incorporating the condition priority. A false blocking condition is assigned the value zero, all other false conditions the value 1 . A true forced condition is assigned the value 3 , all other true conditions the value 2 .
In the expressions FIG. 11A an “&” (“AND”) is processed as the minimum (min) operation, a “I” (“OR”) is processed as the maximum (max) operation. The outcome “0” means “blocked”, the outcome “1” means “not recommended”, the outcome “2” means recommended, and the outcome “3” means forced.
From the above, it should be clear that the methods and systems of the present invention provide computer-driven system that adapts to new information, allows for new information to be readily utilized by instructors, so that the instructor can integrate new information into the existing curriculum.
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At least one content publishing server having a memory storing a map data structure configured by a content author which defines relationships among plural resources and thereby define an informational item of higher granularity content. Each of the plural resources are associated with a first electronic file linked to said map data structure and configured to store information about the usage of the associated resource. Higher granularity content is associated with a second electronic file linked to said map data structure configured to store information about the usage of the higher granularity content. The server which delivers the informational item to a computer gathers feedback usage information reflecting how the higher granularity content and individual ones of the plural resources are used by users. The server updates the electronic files in accordance with the feedback usage information.
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BACKGROUND
Field
[0001] The disclosed teachings relate generally to impact protection for sensor elements. More specifically, the teachings are directed to impact protectors for sensors used in vehicular exhaust systems.
[0002] Sensors used in, for example, automotive applications are built to withstand temperature and vibration extremes in use. However, such sensors may be prone to damage by impact with obstacles during manufacturing of the device with which they are associated, during assembly of the system, such as an automobile, in which the sensor is associated, or during use of the system.
[0003] Hence, there is seen to be a need in the art for an impact preventing device for such sensors.
SUMMARY
[0004] Accordingly, a protection element for a sensor associated with an exhaust system of a vehicle includes a hollow base portion adapted for at least partially surrounding a longitudinal axis of an associated sensor, and first and second legs extending from the base portion and adapted for coupling to a device of the exhaust system.
[0005] In another aspect of the disclosed teachings, an automotive exhaust treatment device includes a sensor mounting boss housing a sensor and extending from a surface of the exhaust treatment device. A sensor protector having a base portion positioned above the mounting boss additionally includes first and second legs extending from the base portion and fixedly coupled to the surface on opposite sides of the boss.
BRIEF DESCRIPTION OF THE DRAWING
[0006] The objects and features of the invention will become apparent from a reading of a detailed description, taken in conjunction with the drawing, in which:
[0007] FIG. 1 a is a perspective view of a piece of tubing showing cutting lines for producing two sensor protectors arranged in accordance with the principles of the disclosed teachings;
[0008] FIG. 1 b is a perspective view of two sensor protectors fashioned by cutting the tubing along the cutting lines shown in FIG. 1 a;
[0009] FIG. 2 is a side view of the tubing of FIG. 1 a prior to cutting it into two sensor protectors in accordance with the principles of the disclosed teachings;
[0010] FIG. 3 is a side view of the tubing of FIG. 1 a taken from a side opposite to that of FIG. 2 ;
[0011] FIG. 4 is a perspective view of an alternative embodiment of a sensor protector arranged in accordance with the principles of the disclosed teachings;
[0012] FIG. 5 is a perspective view of the sensor protector of FIG. 4 shown mounted for protection of a sensor associated with an exhaust treatment device in accordance with the principles of the disclosed teachings; and
[0013] FIG. 6 is a perspective view of a second alternative embodiment of a sensor protection element arranged in accordance with the principles of the disclosed teachings; and
[0014] FIG. 7 is a perspective view of the sensor protection element of FIG. 6 mounted for protection of a sensor associated with an exhaust treatment device in accordance with the principles of the disclosed teachings.
DETAILED DESCRIPTION
[0015] With reference to FIGS. 1 a, 1 b, 2 and 3 , two sensor protector elements are fashioned from tubing 100 by cutting the tubing along the lines shown in FIGS. 1 a, 2 and 3 .
[0016] After the tubing is cut, the two elements shown in the exploded view of FIG. 1 b result in two protectors 102 a and 102 b. A first sensor protector 102 a has a substantially cylindrical base portion from which first and second legs 106 and 108 extend. Similarly, sensor protection element 102 b has a substantially cylindrical base portion with two legs 110 and 112 extending therefrom. FIGS. 2 and 3 show side views of the tube of FIG. 1 a prior to cutting and separation. With this fabrication approach, the mounting legs are integral with their base portions.
[0017] An alternative protection element is shown in FIG. 4 . Sensor protection element 400 has a substantially cylindrical hollow base portion 402 from which two legs 404 and 406 extend. Legs 404 and 406 can, for example, be fixedly coupled to base portion 402 by welding or other suitable attachment processes.
[0018] In automotive applications, the protection elements of FIGS. 1-3 or FIG. 4 , and the sensor which they are designed to protect are, for example, configured in association with an exhaust after-treatment device as shown in FIG. 5 .
[0019] Exhaust after-treatment device 500 may comprise a variety of exhaust system elements, including, without limitation, mufflers, catalytic converters, particulate filters, or simply an exhaust conduit such as an exhaust pipe or manifold.
[0020] In the example shown in FIG. 5 , after-treatment device 500 has an inlet conduit 504 at one end of its housing 502 . Extending outwardly from inlet tube 504 is a sensor and sensor mounting boss 506 . As seen from FIG. 5 , sensor protection element 400 (as shown in FIG. 4 ) is placed such that its base portion 402 overlies mounting boss 506 while legs 404 and 406 extend from base portion 402 on opposite sides of mounting boss 506 and are fixedly coupled to the device at its inlet 504 by suitable attachment means, such as welding. Base portion 402 may be open at its end allowing for the passage of a sensor cable 508 which, in most applications would extend to a unit utilizing the sensor signals, such as an engine control unit of a motor vehicle.
[0021] Surrounding cable 508 as it exits boss 506 is a hardened cable shield 510 fashioned, for example, from a metallic substance. Shield 510 extends from boss 506 through and beyond the boss portion 402 of sensor protection element 400 . In this way, during assembly or in use, cable 508 will not be damaged by coming into contact with protection element 400 .
[0022] A second alternative embodiment of a sensor protection element 600 is set forth in FIG. 6 . Protection element 600 has first and second mounting legs 604 and 605 and a 3-walled base portion 602 adapted to extend along three sides of a longitudinal axis of a sensor being protected. Each wall of the base portion 602 has an associated aperture 606 , 608 and 610 . Base portion 602 terminates at its end opposite mounting legs 604 and 605 at edge surface 612 .
[0023] FIG. 7 sets forth an example application of sensor protection element 600 in an automotive exhaust system environment. As with the application example of FIG. 5 , exhaust after-treatment device 700 may comprise a variety of exhaust system components, including, without limitation, mufflers, catalytic converters, particulate filters, or simply an exhaust conduit such as an exhaust pipe or manifold.
[0024] As seen from FIG. 7 , a sensor and sensor mounting boss 702 extends from after-treatment device 700 . Mounted to device 700 on opposite sides of boss 702 are legs 604 and 605 of protection element 600 . Base portion 602 extends along three sides around a longitudinal axis of sensor and sensor boss 702 so as to surround sensor cable 704 and its cable shield 706 . The open face of base portion 602 faces the vehicle undercarriage or any exhaust system or vehicle component providing a natural impact shield at that side of the sensor boss.
[0025] Sensor protection elements arranged as shown in the teachings herein are suitable for use with a wide variety of sensors, including, without limitation, oxygen sensors, temperature sensors, pressure sensors, nitrous oxide sensors, ammonia sensors, etc.
[0026] The detailed description has been set forth for the sake of example only and is not to be construed as a limitation on the invention. The invention will be found in the appropriately interpreted appended claims.
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An impact protection element for a sensor housed in a boss features a hollow base element adapted to overlie the boss and a pair of legs extending along opposite sides of the boss.
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BACKGROUND OF THE INVENTION
This invention relates to the field of rocket propulsion, and more particularly steering of rocket propelled missiles or vehicles by thrust vector control.
Thrust vector control with large deflection angles (±20° and more) has, in the past, required the use of gimballed rocket motors or gimballed nozzles with the associated complexity of gimbal servos and related precision mechanisms that are exposed to large forces. The use of secondary injection of fluids such as liquids or cold or hot gas generally limits the thrust vector control deflection angle to approximately ±6°.
There has therefore existed an unfulfilled need for a thrust vector control system that can operate reliably, rapidly and effectively to produce not only a relatively constant axial thrust, but also thrust vectors that yield the lateral forces necessary for desired pitch, yaw and roll maneuvers without the complex mechanization associated with the gimballed systems. In answering that need, an additional and important consideration is a need for compatability with propulsion gas generators of the constant burn rate type. Such compatability requires a substantially constant level of total utilization of the gas generator output irrespective of modulation or apportionment between different thruster nozzles during various maneuvers.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is a principal object of this invention to provide an improved thrust vector control system for propulsion and steering of missiles or vehicles.
Another object of the invention is to provide a thrust vector control system that functions to provide thrust at large angles while avoiding the need for gimballed rocket motors, nozzles, or other thruster elements and their associated mechanizations.
Yet another object is the provision of a thrust vector control system that is compatible with constant burn rate thrust gas generators.
Still another object is to provide a missile or vehicle propulsion system having thrust vector control through a combination of thrusters disposed at fixed predetermined angles relative to the vehicle frame of reference and operable by pulse duration modulation to achieve substantially constant axial thrust even while performing one or more maneuvers involving lateral thrust components.
As another object the invention aims to accomplish the foregoing while providing a system that is relatively simple and reliable in use.
Other objects and many of the attendant advantages will be readily appreciated as the subject invention becomes better understood by reference to the following detailed description, when considered in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end elevational view of a missile or vehicle including a thrust vector control system embodying this invention;
FIG. 2 is a fragmentary sectional view of the missile or vehicle of FIG. 1, taken substantially along line 2--2 thereof;
FIG. 3 is a tabular graphic illustration of various control modes of the system of FIGS. 1 and 2.
FIG. 4 is an end elevational view of a missile or vehicle including an alternative embodiment of the invention.
FIG. 5 is a fragmentary sectional view of the missile or vehicle of FIG. 4, taken substantially along line 5--5 thereof; and
FIG. 6 is a tabular, graphic illustration of various control modes of the system of FIGS. 4 and 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a missile or other vehicle 10 having an elongated, generally cylindrical body 12 is provided with a reaction generating thruster system at its after end, which system embodies thrust vector control according to this invention. In the form of the invention being described as an example, there are provided four thruster units generally indicated at 16, 18, 20, and 22, the units comprising valves 16a, 18a, 20a, and 22a, and associated thrust nozzles 16b, 18b, 20b, and 22b, respectively.
While the invention contemplates the use of any thrust gas controlling valve having the ability to interrupt and reestablish a full flow of thrust gas with considerable rapidity so as to provide a controllably pulsed output. The actual construction of such valves is not necessary to an understanding of this invention and so will not be described in detail. Suffice it to say here that valves of the type known in the art as vortex valves, which incorporate poppet valves, spool valves, or fluidic devices operated by high pressure control fluid, are suitable.
The thruster units 16-22 are disposed so as to diverge at predetermined angles θ to the frame of reference of the vehicle. These angles θ, in this example, lie in planes passing through the central axis of the vehicle, are equal in magnitude, and can be large, e.g., 20°, or more. The thruster units 16-22 are supplied with thrust producing warm gas by a toroidal, gas generator 26 having passage means communicating with the vortex valves 16a-22a. The thrust gas generator 26 is capable of providing a substantially constant total mass-flow-rate.
High pressure control fluid is provided by a centrally located high pressure gas generator 30 connected by a conduit 30a and manifolding 30b to the poppet, spool valves, or fluidic elements of the vortex valves 16a-22a. A guidance system 34, using any well known navigational technique, provides control signals, represented by flow lines 36, 38, 40, 42, to the vortex valves 16a-22a, respectively.
MODE OF OPERATION
The signals, lines 36-42 regulate the duty cycles of the respective vortex valves by pulse duration modulation in a manner to provide not only continuous thrust for effecting forward motion of the vehicle 10, but also resultant thrust vector control for effecting pitch and yaw in accordance with the interest of the guidance system.
To this end, and with reference additionally to FIG. 3, the respective vortex valve controlled thrustors 16, 18, 20, and 22 are individually controlled in pulse duration modulation, with the thrust vectors F 1 , F 2 , F 3 , and F 4 corresponding to the average thrust forces generated by the corresponding thrusters.
Beginning at the left in FIG. 3, the first example depicts normal operation with no control forces. In that case, all thrusters are pulsed at 50% duty cycle. Thus, the thrusters 16, 18, 20, and 22 provide thrust pulses 50, 52, 54, and 56, respectively. These pulses are at a frequency that minimizes vibration. Preferably, opposite thrusters are pulsed in synchronism and alternate with pulses of the adjacent thrusters. The net result is that lateral components of the thrust vectors F 1 and F 3 and of vectors F 2 and F 4 cancel to produce a zero lateral resultant, while the axial components of F 1 and F 3 add to provide a resultant axial thrust vector A 1 ,3 and the axial components of F 2 and F 4 add to provide a resultant axial thrust vector A 2 ,4.
In the next example, where a pitch-up maneuver is effected, the operation of the opposite thrusters 16,20 is altered to provide a continuous or prolonged pulse of the thruster 16 as shown at 50' while the thruster 20 is shut off completely. The opposite thrusters 18,22 continue to be simultaneously pulsed at the 50% duty cycle of each as indicated at 52' and 56'.
Again, the lateral components of the thrust vectors F 2 and F 4 of the thruster pair 18,22 are cancelled. However, the sideways or lateral component of the vector F 1 of the one operating thruster 16 is not cancelled and is indicated at L 1 . The axial component of the thrust vector F 1 is indicated at A 1 in this example and, because the thruster 16 is operating at 100% of its duty cycle during the maneuver, F 1 is increased and A 1 is equal to the axial component A 2 ,4, as well as to the former combined axial components A 1 ,3 of the thrusters 16,20 of the former example. It will be recognized that the total axial thrust remains unchanged during the pitch-up maneuver. Also, that the total thrust gas flow remains unchanged. The latter is important in that it permits use of the mentioned constant rate thrust gas generator 26. It will also be recognized that the reaction of the vehicle is in movement of the aft end in the opposite directions to the thrust vectors or components being discussed.
Turning to the next example, a pitch down and yaw to left maneuver is being executed. In this manuever, the thrusters 16 and 22 are shut down and the thrusters 18 and 20 are operated at 100% of their duty cycles as shown at 52" and 54', respectively. The resulting axial components A 3 and A 2 maintain the total axial thrust constant, while the lateral components L 3 and L 2 effect the desired vehicle maneuver.
The last example, a yaw to right involves normal 50% pulsing of the opposite thrusters 16, 20 as indicated at 50" and 54" and operation of the other opposing thrusters to provide a zero duty cycle by thrusters 18 and 100% duty cycle of thruster 22 as shown at 56". As before, the axial components remain constant. The lateral components, however, are cancelled for the thrusters 16, 20 as in the first example, and a lateral component L 4 of the vector F 4 exists that produces the desired yaw maneuver.
An alternative embodiment of the invention is illustrated in FIGS. 4 and 5, which embodiment permits thrust vector control to provide the additional controlled maneuver of roll in either direction about the axis of the vehicle. In this embodiment, a vehicle 60 is provided with eight thrusters 62,64, 66, 68, 70, 72, 74, and 76 each individually comprising and controlled by a vortex valve and including a suitable nozzle. These eight thrusters are disposed at fixed thrust angles relative to the vehicle frame of reference and are pulse duration modulated, for example between zero, 50% and 100% duty cycles, to accomplish the desired manuevers while maintaining a substantially constant average axial thrust and total gas mass-flow-rate.
As is best seen in FIG. 4, the eight thrusters are arranged in four pairs such that 62 and 64 constitute one pair, 70, 72 an opposite pair, while 66, 68 constitute a pair with 74,76 the opposite pair. It will be observed that opposite pairs are set at angles diverging to opposite sides of the vehicle and further that the thrusters of a given pair are canted or set at angles diverging to opposite sides of a plane extending between those thrusters and the thrusters of the opposite pair.
A supply of thrust producing warm gas is ducted to the four pairs of vortex valves of the four thruster pairs from a toroidal gas generator 80, via ducts 82. A supply of high pressure control fluid is provided to the eight vortex valves from a centrally located gas generator 84 via ducts 86. A guidance system, not shown, provides control signals to those valves to effect pulse duration modulation of the thrusters in accordance with the invention to implement maneuvers of pitch, yaw, and roll, or combinations thereof.
Now, referring to the first or left hand control situation of FIG. 6, when all eight thrusters are pulsed between full off and full on at a 50% duty cycle no pitch, yaw, or roll is induced because all lateral components are cancelled. The total axial thrust will be the sum of the axial components of the eight thrust vectors F 1 , F 2 ,-F 8 . Inspection of FIG. 6 will further reveal the pulse modulation program for operation of the eight thruster valves to effect conditions of pitch, yaw, roll, and combinations thereof, all while maintaining substantially constant average mass-flow-rate and axial thrust.
Examples having been given of embodiments of the invention employing 4 and 8 thruster units, it will be understood to those skilled in the art, without further description, that the invention can readily be embodied in other even numbered configurations. Thus, the thruster units could be 2, 4, 6, 8 or more in number, wherein antipodal units or pairs are pulse duration modulated to produce the desired lateral thrust components while maintaining a constant total average axial thrust.
Obviously, other embodiments and modifications of the subject invention will readily come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing description and the drawing. It is, therefore, to be understood that this invention is not to be limited thereto and that said modifications and embodiments are intended to be included within the scope of the appended claims.
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A missile thrust vector control system using fixed valves and nozzles in n numbers, as 4 or 8, mounted so that the thrust vectors operate at preselected angles to the frame and are pulse modulated in certain combinations to produce thrust vectors the sums of which provide desired deflections in pitch, yaw, and roll, without altering axial propulsion thrust.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase Application of PCT International Application No. PCT/IB2014/061457, International Filing Date, May 15, 2014, claiming priority to Italian Patent Application No. TO2013A000396 (102013902156593), filed May 16, 2013, each of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a process for the production of micro- and nanofibres of poly(cyanoacrylate), to continuous, uniform coating layers obtained from said fibres and to substrates or articles provided with said coatings.
The production of polymer nanofibres, which are characterized by their high surface area/volume ratio and by their mechanical properties, is of considerable interest in various applications such as the production of reinforced composites, of materials used as tissue scaffolds, as filter media and for controlled drug delivery.
BACKGROUND OF THE INVENTION
The main techniques for the production of polymer nanofibres comprise processes of extrusion of a polymer melt through holes of nanometric dimensions in a template and processes of electrospinning. Electrospinning involves the use of a source of high voltage for generating electrically charged polymer jets, which are collected on a substrate as a mat of nanofibres. This technique requires the polymer to be processable in the liquid state and to be able to withstand high voltage.
In practice, however, these known techniques are not applicable for the production of nanofibres polymerized from cyanoacrylate monomers, commonly known as “Super Glue®” or “Super Attak®”. The property of these monomers of polymerizing instantaneously and irreversibly in the presence of moisture in fact makes the electrospinning process rather difficult. The polymerization of the monomer triggered by the humidity of the air in fact causes obstruction of the point of the needles during processing. Moreover, the product collected on the target substrate is generally in the form of drops or beads that are not suitable for electrospinning.
Some very recent works that dealt with the problems relating to the production of poly(cyanoacrylate) nanofibres proposed, as the only existing method available for producing such nanofibres, the condensation of vapours of cyanoacrylate on specially conditioned and structured surfaces.
In contact with such surfaces, the monomers polymerize in the form of fibrillar network structures of micrometric or nanometric dimensions [1-3].
For example, fingerprints left on surfaces can act as sites of initiation for vapours of cyanoacrylate monomer and polymerization follows the thin lines of the fingerprints, forming poly(cyanoacrylate) fibres. However, the main disadvantages of these approaches concern the difficulty of scale-up and lack of process control during moisture-activated polymerization, which leads to a crosslinked polymer structure that is in the form of a hard white solid.
In this state, crosslinked cyanoacrylates cannot be dispersed in common solvents in order to be used as polymer solutions.
SUMMARY OF THE INVENTION
The general aim of the present invention is to provide a process that is simple, economical and rapid, and that can easily be implemented industrially, for producing micro- and nanofibres from cyanoacrylate monomers.
A specific aim of the invention is to provide a process that allows large quantities of micro- and nanofibres to be produced by direct electrospinning from solutions.
In view of these aims, the invention relates to methods for the production of micro- and nanofibers of poly(cyanoacrylates), as described and claimed herein.
The invention also relates to polymer coatings in the form of a uniform, continuous layer, obtained from the aforementioned micro- and nanofibers, as well as articles and/or substrates provided with said coating layers, as described and claimed herein.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1( a ) and ( b ) illustrate fibers with diameter controlled from about 300 nm to about 1.3 μm ( FIG. 1( c ) );
FIGS. 1( a ), ( b ) and ( c ) are photographs obtained with the scanning electron microscope (SEM), which illustrate the electrospun nanofibers at various magnifications:
(a) magnification ×1000: nanofibers obtained from 5% w/v solution of polymer in acetone;
(b) magnification ×5000 of the fibers of FIG. 1( a ) ;
(c) magnification ×2000: nanofibers obtained from 10% w/v solution of polymer in acetone.
DETAILED DESCRIPTION
The process according to the invention applies to any monomer of alkyl-2-cyanoacrylate (where alkyl can be C 1 -C 8 ), among which the monomers that are the most representative and of greatest interest from the practical and industrial standpoint are methyl- or ethyl- or octyl-2-cyanoacrylate and mixtures thereof.
The first step of the process according to the invention envisages mixing the cyanoacrylate monomer in a dipolar aprotic solvent, including in particular dimethylformamide (DMF), dimethyl acetamide (DMAc), dimethyl sulphoxide (DMSO) and/or N-methyl-2-pyrrolidone (NMP); of these, DMSO is particularly preferred.
The aforementioned dipolar aprotic solvent performs the dual function of solvent for the cyanoacrylate monomer and catalyst for initiating its polymerization, leading to the formation of a viscous gel of cyanoacrylate polymer or prepolymer.
The cyanoacrylate monomer and the solvent can be mixed in any proportions by volume that lead to formation of the gel, for example with volume ratios from 0.1:1 to 2:1. When using DMSO, generally it is preferable to mix equal volumes of cyanoacrylate monomer and DMSO; mixing can be carried out by dropwise addition of cyanoacrylate monomer to the dipolar aprotic solvent, for example contained in a glass test tube.
Using a Vortex mixer, the contents can be submitted to agitation to ensure complete mixing of the two liquids. The process that leads to formation of the gel as a result of contact of the cyanoacrylate monomer with the solvent is exothermic, therefore during formation of the gel it is preferable for the test tube or the container in question to be kept in a cold environment for the purpose of accelerating the exothermic gelling process.
After gelling, preferably the gel is left to equilibrate at room temperature.
The second step of the process involves dissolution of the gel in a solvent, having properties suitable for electrospinning, which has properties of solvent for polyacrylates.
Solvents suitable for the electrospinning process comprise acetonitrile, ketones, such as in particular acetone, chlorinated hydrocarbon solvents and simple C 1 -C 4 carboxylic acids such as formic acid and acetic acid. However, aqueous solvents, water, alcohols, and linear hydrocarbon solvents such as hexane and heptane, are not suitable.
In general, it is possible to use any conventional solvent that is able to dissolve a polyacrylate and has the desired electrical properties necessary for the electrospinning process. The important electrical properties of the solvent in relation to electrospinning are:
a dipole moment preferably above 3 debye; a dielectric constant preferably above 20; and a boiling point preferably below 110° C.
The preferred solvents are acetone and/or acetonitrile.
As stated, the gel is dissolved using an amount of solvent suitable for obtaining a solution of poly(cyanoacrylate), suitable for electrospinning; typically, the gel is dissolved in the solvent in proportions from 1% to 30% w/v.
This solution can be submitted to electrospinning using conventional electrospinning equipment.
Conventional electrospinning equipment comprises a syringe filled with the polymer solution, a syringe pump, a source of high voltage and a collector. The metal needle of the syringe typically has the function of electrode for inducing electric charges in the solution, under the influence of a strong electrostatic field.
When the charge repulsion exceeds the surface tension of the polymer solution, a charged polymer jet forms, which is accelerated towards the collector. On the way, the solvent evaporates and polymer micro- and nanofibres collect on the collector. The diameters of the fibres can vary from a few nanometers to values above 5 μm.
In contrast to the cyanoacrylate monomers, the modified poly(cyanoacrylate) is characterized by excellent electrospinning properties, as the nanofibres obtained are long and of uniform diameter, without formation of porous or bead-like structures.
The size and the morphology of the nanofibres can easily be controlled by varying the concentration of the polymer in the solvent, without using surfactants or salts, which are required for other polymeric materials. Moreover, nanofibrous mats can be deposited over a very wide area (larger than 100 cm 2 ) and collected randomly or aligned, by varying the size of the collector and thus also the applied electric field.
In particular, the main advantage of the process according to the invention is that the polymerization triggered by the dipolar aprotic solvent does not give rise to rapid polymerization with crosslinking, such as occurs with other initiators such as the amines. In these conditions, moisture does not cause rapid and irreversible polymerization, so that the cyanoacrylate polymerized (gelatinized) in this form is not thermosetting.
The process allows a layer of nanofibres with controlled thickness and density to be deposited on various substrates, such as glass, metals and plastics. It is observed that the fibres can be melted on the surfaces on which they are deposited, for example by thermal treatment in a stove, with a hot plate, with a microwave oven and/or laser, at a temperature between 100° and 300° C. with treatment times typically between 10 seconds and 5 minutes, depending on the method of melting used and the thickness of the mat of fibres. Non-porous, transparent coatings are obtained that have good scratch resistance, antifriction properties that make them useful as lubricating coatings, hydrophilic self-cleaning properties and properties of non-condensation of water vapour (antifogging properties). For example, water vapour condensed on a glass substrate coated with the fused nanofibres takes, in normal conditions of temperature and humidity, half the time to evaporate completely compared to an untreated substrate. Moreover, mechanical strength tests conducted on the coating of fused fibres demonstrate that the coatings thus obtained have a lower coefficient of friction than Teflon (typically used as lubricant). They are also characterized by excellent adhesion to the underlying substrate. In addition, the coating of fused nanofibres of polymerized cyanoacrylate has low surface roughness and good optical transparency (100% transmittance for wavelengths in the visible range). This coating, when applied to plastic substrates (for example of polydimethylsiloxane, PDMS), promotes the release of other polymeric materials (for example of the same PDMS) cured in situ on its surface (anti-sticking properties). This makes it possible to use the process according to the present invention as a substitute for other technologies, such as deposition of silanization solutions, of Parylene and of Teflon.
The invention therefore also provides a process for the deposition of coatings, as an alternative to the vapour phase deposition of polymers; in particular, the exceptional properties of the coatings thus obtained cannot be achieved if the coatings are formed by other processes, such as spin-coating and casting.
The cyanoacrylate coating developed also has good characteristics of biocompatibility, promoting cell growth more than the substrates conventionally used for these purposes (such as glass, polystyrene).
Further features of the process according to the invention are illustrated by the embodiment example that follows.
EXAMPLE
A poly(cyanoacrylate) gel was prepared using ethyl-2-cyanoacrylate and dimethyl sulphoxide mixed in 1:1 ratio by volume, following the mixing procedure described above.
Solutions of poly(cyanoacrylate) gel in acetone and acetonitrile were prepared with a concentration from 2% to 20% w/v. Each solution was collected in a 1-ml syringe fitted with a stainless steel needle with inside diameter of 0.5 mm, acting as spinneret, and connected to a generator of high voltage.
The syringe was attached to a syringe pump for maintaining a flow rate of 3-5 ml/h, depending on the viscosity of the solution. A copper plate covered with aluminium foil was used as the collector. The voltage applied and the distance from the tip to the collector were 10-15 kV and 15 cm, respectively.
The size of the fibres produced can be varied by acting upon the concentration of the polymer solution: an increased concentration of the solution greatly increases the solution viscosity, allowing fibres of larger diameter to be produced.
The electrospun nanofibres thus obtained can be thermally treated in fusion (for example at a temperature of about 130° C.) to form transparent coatings on glass substrates or on other surfaces, obtaining coatings with hydrophilic, self-cleaning properties.
The coating obtained has high adherence to the substrate, antifriction and anti-scratch properties and hydrophilic behaviour with extremely low hysteresis, as well as anticondensation properties and biocompatibility.
The invention thus provides a process that is economical, especially when using DMSO as catalyst, which is of low cost and does not require further purification relative to the grade that is commercially available.
The fibres can be deposited on any surface, without requiring pretreatment or patterning; the polymer constituting the nanofibres and the coatings is biodegradable.
Moreover, the polymerization and electrospinning process proves to be suitable for allowing the incorporation of functional nanofillers in the fibres by direct dispersion or by means of precursors; that is, various natural or synthetic polymers can additionally be mixed in the nanofibres.
The main application is the production of filters, membranes, biomedical scaffolds, medical devices, mechanical reinforcements, coatings, as well as applications in the textile industry.
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Methods are provided for the production of poly(cyanoacrylate) micro- or nanofibers which include mixing the cyanoacrylate monomer with a dipolar aprotic solvent to form a poly(cyanoacrylate) gel, dissolving the gel in a solvent for acrylates to form a solution suitable for electrospinning, and submitting the solution thus obtained to electrospinning to form said micro- or nanofibers. The micro- or nanofibers thus obtained can be used to form coatings that adhere to a substrate as a result of thermal treatment.
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BACKGROUND OF THE INVENTION
The present invention relates to a pressure reducer for hydraulic brake systems comprising a piston penetrating a sealing ring with play, a piston head of enlarged diameter forming a valve together with the sealing ring, which valve is able to separate an inlet chamber and an outlet chamber in the housing, and, in the rest position, a first spring presses the piston against a stop in the outlet chamber and a second spring presses the sealing ring in the same direction against a step of the housing to thereby define the valve stroke.
In a known pressure reducer of this type, such as disclosed in FIG. 4 of German Patent DE-AS No. 1,555,387, the piston may be loaded by a spring whose initial tension determines the change-over pressure of the pressure reducer. With a sealing ring inserted, a second spring concentrically enclosing the piston exerts pressure on the sealing ring, thus reliably pressing it against the step. The valve stroke so established will bring about an exactly defined change-over point as the inlet pressure increases. However, the second spring will have a retarding effect on the quick opening of the valve upon a drop in the inlet pressure, since the axial displacement of the sealing ring required to this end will be possible only if the inlet port side pressure has decreased to the point that the initial tension of the second spring has been overcome. By means of a sealing washer, the other end of this second spring presses a second annular seal against the front surface of the inlet chamber, the second annular seal serving as a piston seal. The thus produced deformation of the sealing ring material will lead to a wear which cannot be neglected.
It is also known from FIGS. 1 and 3 of German Patent DE-AS 1,555,387 to dispense with such a second spring for the loading of the valve sealing ring to ensure a quick opening of the valve upon a drop in the inlet pressure. Then, however, the sealing ring will not reliably abut against the housing step in the rest position. Because of the thus undefined valve stroke the change-over pressure is not exactly determined.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a pressure reducer of the type described above, having an exactly defined valve stroke and safeguarding a quick opening of the valve upon a drop in the inlet pressure.
A feature of the present invention is the provision of a pressure reducer for hydraulic brake systems comprising a housing having a longitudinal axis; a piston disposed in the housing coaxial of the axis penetrating a sealing ring with play disposed in the housing coaxial of the axis, the piston having a head of enlarged diameter forming a valve in cooperation with the sealing ring, the valve controlling a connection between an inlet chamber and an outlet chamber disposed in the housing; a first spring disposed in the housing coaxial of the axis to press the head against a stop in the outlet chamber in a rest position of the reducer; a second spring disposed in the housing coaxial of the axis to press the sealing ring toward the stop against a step in the housing, the first and second springs, the stop and the step defining a stroke of the valve; and an engaging plate disposed in the housing coaxial of the axis between the sealing ring and the second spring, the engaging plate being capable of being carried axially along by the piston in a direction away from the stop after the piston has travelled a predetermined distance less than the stroke of the valve.
In this construction the second spring will be fully effective in the rest position of the valve. The sealing ring will be pressed against the step and there will be an exact definition of the valve stroke. In the working position, on the other hand, the second spring will be lifted off of the sealing ring by means of the engaging plate carried along by the sealing ring. Thus, upon a drop in the inlet pressure there will be an immediate axial displacement of the sealing ring without having to overcome the force of a spring. Thus, the desired quick opening of the valve is brought about.
A further advantage lies in the fact that the second spring is working in parallel with the first spring at the time of the valve's closure. Thus, it is possible to use a weaker spring as a first spring for a given change-over point. In doing so, the ratio of the forces of the springs may be selected freely within a large range. In particular, it is also possible to choose a relatively strong spring as the second spring. This will enable a considerable reduction of the size of the springs and permit the structural size of the pressure reducer to be kept very small, in particular in the case of a fixed change-over value.
It will be an advantage for the engaging plate to have engaging means pointing inwards and projecting up into the path of motion of a piston shoulder. Such an engaging plate can easily be formed out of sheet metal and easily mounted by being slipped over the piston.
It is possible to rate the first spring small enough so that it will engage an axial bore of the piston which will lead to a considerable reduction of the structural size.
Further, the two springs may axially overlap. Thereby it will be possible to achieve an axial shortening of the pressure reducer.
The same purpose will be served if the second spring axially overlaps the usual piston seal.
It will further be advantageous if, on the outside the piston seal is surrounded by a support of the housing and if the other end of the second spring is supported on a ring washer resting at the front face of this support of the housing. In this way, the piston seal will be secured reliably. Yet, it will not be loaded by any force of a spring, the wear being correspondingly small.
In a preferred embodiment, the piston is disposed completely in a chamber of the housing which exceeds the piston length by an amount only slightly more than the valve stroke; a coaxial connecting bore branches off of this chamber of the housing on the outlet port side; and a coaxial connecting branch begins a small distance from the other end of the chamber of the housing. Thus, a pressure reducer will result, which will be easy to fit into the normal connection bore of a pressure generator, e.g. of a master cylinder, at whose other end a pressure line's connecting branch normally directly connected with the pressure generator may be connected, and whose space requirements will be very small, e.g. less than 40 mm in the axial direction and less than 30 mm in the diametric direction.
BRIEF DESCRIPTION OF THE DRAWING
Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawing in which:
FIG. 1 is a longitudinal cross sectional view of a first embodiment of a pressure reducer in accordance with the principles of the present invention; and
FIG. 2 is a longitudinal cross sectional view of a second embodiment of a pressure reducer in accordance with the principles of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the housing 1 comprises a main part 2 and an insert 3 inserted therein and additionally secured by means of a flanged rim 4. A seal 5 seals the two with respect of each other. At insert 3 there is a coaxial connecting branch 6 with a bore 7 which leads into an inlet chamber 9 via a diagonal bore 8. Main part 2 has a coaxial connecting bore 10 communicating with an outlet chamber 12 via a bore 11. Further, insert 3 accommodates a piston chamber 13 communicating with the atmosphere via a diagonal bore 14.
A piston 15 penetrates a sealing ring 17 with play. Piston 15 has an enlarged piston head 16. By means of a sealing edge, piston head 16 forms a valve 19 by abutting the front face 18 of sealing ring 17. Valve 19 separates inlet chamber 9 from outlet chamber 12. Piston 15 is passed through a piston seal 20 outwards into piston chamber 13. Piston seal 20 is kept in insert 3 by a plate 21 firmly fastened thereto. Further, piston 15 has an axial bore 22 containing a first spring 23. Spring 23 has one end abutting the bottom of axial bore 22 and the other end abutting a front face 24 of insert 3. A conically shaped second spring 25 acts on sealing ring 17 by means of an engaging plate 26, pressing sealing ring 17 against a step 27 of housing 1 in the rest position. Since spring 23 presses an end of piston 15 against a stop 28 at the bottom of outlet chamber 12 there will be an exact definition of the valve stroke s. The other end of second spring 25 supports itself at a surface 29 of insert 3, thus, overlapping both first spring 23 and piston seal 20 in the axial direction. Engaging plate 26 has engaging means 30 pointing inwardly and lying in the path of motion of a shoulder 31 of the piston 15. In the represented rest position, engaging means 30 is spaced a distance x from shoulder 31. Distance x is smaller than the valve stroke s.
Inlet chamber 9, outlet chamber 12 and piston chamber 13 together form a chamber 32 of housing 1 whose axial length slightly exceeds the length of piston 15 plus the valve stroke s. Due to the axial overlapping of springs 23 and 25 as well as the fitting of spring 23 in axial bore 22 this small length will be sufficient which in a practical embodiment will only need to amount to slightly more than 20 mm (millimeters).
Inlet chamber 9 is connected with a pressure generator, e.g. with a brake-pedal-operated master cylinder. It may be screwed directly into a connecting bore of this pressure generator. Outlet chamber 12 is connected with a brake cylinder, e.g. with a rear wheel cylinder. In doing so, a usual connecting line, as normally introduced into the master cylinder, may be screwed directly into connecting bore 10. After inserting connecting branch 6 into a corresponding connecting bore the length of the pressure reducer will protrude very small. In a practical embodiment it was less than 40 mm.
Upon an increase of the inlet pressure P e during operation, this pressure will be transmitted directly into outlet chamber 12 by way of open valve 19. Thus, the outlet pressure P a will equal the inlet pressure. With the inlet pressure increasing, piston 15 will be displaced to the right in the drawing, since its surface facing inlet chamber 9 is smaller than the surface facing outlet chamber 12. After a distance x, piston 15 will carry along second spring 25 by means of engaging plate 26. Thus, there will be an increase in the prestressing force against which piston 15 is closing. The entire valve stroke s will therefore be achieved at a defined inlet pressure. Upon a further increase in the inlet pressure there will result a slower increase in the outlet pressure P a in a known manner, since the pressures will change dependent upon the ratio of the inlet port side and outlet port side surfaces of piston 15. If now again there is a drop in the inlet pressure P e the then prevailing outlet pressure P a will immediately displace sealing ring 17 to the right in the drawing, since it will not be loaded by spring 25. This displacement will lead to an immediate opening of valve 19 and, hence, to a pressure compensation which will release the brakes.
In the embodiment according to FIG. 2, the same mode of operation will result. Therefore the same reference numerals will be used for like parts. Insert 3, however, is not flanged to main part 2 of housing 1, but is rather fastened by means of a thread 33. On the side spaced from engaging plate 26, spring 25 supports itself on a ring washer 34 which keeps annular seal 20 in its support 35 of housing 1, thus taking over the function of plate 21. In doing so, ring washer 34 will rest on the front face 36 of support 35 of housing 1. Consequently, piston seal 20 will not be loaded by the force of spring 25, yet may easily be replaced if insert 3 is screwed out of main part 2.
This principle is also applicable in pressure reducers having no fixed change-over points. In this case, first spring 23 is given a different and/or variable prestress by an outside control element.
While we have described above the principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims.
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A pressure reducer for hydraulic brake systems comprising a valve formed by the head of a spring-loaded piston and by a sealing ring which is urged by a spring against a step of the housing. Arranged between the spring and the sealing ring is an engaging plate which is carried along by the piston after the piston has travelled an amount smaller than the valve stroke. This results in an exactly defined valve stroke and at the same time results in a quick opening of the valve upon decrease of the inlet pressure.
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This application claims priority under 35 U.S.C. 119 from United States Provisional Application Serial No. 60/211,485 filed Jun. 14, 2000.
The present invention relates to sports equipment bags and more particularly to a novel method to expand the use of sports bag from transport/protection utility only to also drying and optional scenting utility.
Sports equipment, and notably hockey and football equipment, is often comprised of many items for the individual user. Together these many items make for a bulky and unwieldy combination of items to move from place to place. Thus, this sports equipment is usually transported in a bag.
Sports equipment has a near legendary reputation for becoming wet from sweat, and for becoming foul-smelling as well. The foul smelling sports equipment, and the space necessary to dry it, is currently an ongoing source of conflict in many living situations. Players are often forced to dry their sports equipment in risky, unsuitable, or destructive environments, such as back yards, garages, balconies, where they may be subject to theft or cold or damp weather.
Also, since many games are played in close proximity to each other from a time perspective, a player often does not have enough time to dry the equipment before the next use. This makes for a clammy and unpleasant feeling; putting on wet equipment.
In current practice, the problems of wetness and foul smell are addressed in the following ways.
For wetness, the sports equipment is removed from the sports bag, and spread out to dry on racks, on the ground, or in the sun, and then, when the equipment is dry, the equipment is placed back into the sports bag. This requires diligence and lengthy periods of time.
For foul odor, it is common practice to place aroma packs, air fresheners and the like into the sports equipment bag. However, if the sports equipment is not removed from the bag to dry, the air fresheners effect is greatly minimized.
Hanging drying and/or anti-wrinkling bags for clothes are shown in U.S. Pat. Nos. 5,555,648 (Griffin) issued Sep. 17, 1996; 5,730,006 (Conley) issued Mar. 24, 1998; 4,572,364 (Jordan) issued Feb. 25, 1986 and 3,739,492 (Brooks) issued Jun. 19, 1973 but none of these is suitable for sporting equipment including pads and the like which are awkward and bulky and many of these include heat and/or steam which are unsuitable for the sports equipment.
There remains then, an opportunity to improve the situation. The present invention allows for such improvement.
SUMMARY OF THE INVENTION
The present invention is concerned with a method and apparatus to allow wet and foul smelling sports equipment to remain in the sports bag and yet, while still remaining in the sports bag, the equipment will become dry and fairer smelling.
According to the present invention, there is provided a method for drying sporting equipment and the like comprising:
transporting the sporting equipment in a sporting equipment bag having a filler opening through which the equipment is inserted into the bag and handles for carrying the bag;
with the equipment in the bag, closing the opening of the bag;
providing an air flow opening in the bag separate from the filler opening;
attaching a blower fan to the air flow opening of the bag;
and actuating the fan to force air into the bag until the sporting equipment is dry from the air passing around the sporting equipment and escaping from the bag.
While the present invention has been described in the context of sporting equipment, it is apparent that the present invention will in practice be used to dry various items, not just sports equipment. Many other activities make use of bulky items which require drying or scenting. It will be used as a general purpose dryer.
Also, the size of the bag and fan can theoretically have no limit and be applied to many different things.
While the bag is included as an element of this construction, it will be appreciated that the present invention may be sold as a kit of parts for assembly into a bag so that an existing bag will be formed into a drying arrangement according to the present invention.
The bag may have a second air flow opening generally opposite to the first air flow opening or optionally, air may escape through the existing filler opening.
Preferably the air flow opening or openings is covered by a screen or mesh or a more rigid grid arranged to prevent the passage through the airflow opening of the equipment within the bag.
Preferably the fan includes a fan housing and wherein the airflow opening includes a peripheral engagement member engaged around a periphery of the fan housing such that the fan and fan housing are contained within the peripheral engagement member.
Preferably there is provided an air freshener in a pocket at or adjacent the bag airflow opening.
Preferably the filler opening is arranged at a top of the bag and the bag includes a bottom wall for sitting on a support surface and side walls standing upwardly from the bottom wall with the sporting equipment resting on the bottom wall and wherein the airflow opening is in one side wall.
Preferably two of the side walls are at ends that is the walls generally at right angles to the length of the handles and the airflow opening is in one end. However the openings may be located at other places in the bag wall, but generally not in the bottom where the bag can simply sit on its bottom with the equipment resting against the bottom. Such handles are generally attached to the sides or to straps extending around the sides with the insertion opening parallel to the handles but other constructions may be included.
Preferably the air flow opening includes a mounting ring having a peripheral clamping arrangement for clamping the fabric of the bag which has a first ring element on one side of the wall and a second ring element on the other side of the wall for clamping the fabric wall of the bag therebetween and the fan includes a fan housing which fits into the ring and locks in place. However the fan may also be permanently attached to the bag so as to be carried thereby and be available at all times and places for the drying action.
Preferably the ring includes a screen having a concave outside face and the fan housing includes a screen having a convex face fitting against the screen of the ring.
Preferably a second rigid ring similar to or identical to the mounting ring is arranged in a wall of the bag opposite to the mounting ring. The use of the same ring structure reduces cost of manufacture by avoiding the necessity for different parts.
Preferably there is provided an air freshener housing located on an outside face of the fan housing of the fan where the air freshener housing can be opened and closed to allow entry of more or less of the air freshener material.
According to a second aspect of the invention there is provided a fan assembly for mounting on a fabric wall of a bag comprising:
a mounting ring having a peripheral clamping arrangement for clamping the fabric of the bag for supporting the ring in a hole in the wall;
and a fan having a fan housing which fits into the ring and locks in place in the ring so as to blow air through the ring into the bag.
The purpose of the detachable fan is so that the fan can remain safely at home while the bag is in use. Also, this makes the bag lighter, not having to carry the fan around. However as an alternate embodiment it would be possible to have the fan permanently mounted. This would have the benefit of not having to attach and detach the fan, but would add slight weight to the bag.
Another option would be to secure the existing fan as described in the drawings permanently to the mounting rings by means of a bolt or screw, thus locking the fan into place.
According to a third aspect of the invention there is provided an apparatus for drying sporting equipment and the like comprising:
a sporting equipment bag having a bag bottom, bag side walls standing upwardly from the bag bottom, a closable filler opening through which the equipment is inserted into the bag and handles on the bag side walls for carrying the bag;
an air flow opening in at least one of the bag side walls separate from the filler opening;
and a blower fan for mounting into the air flow opening of the bag.
The invention as defined above may have one or more of the following advantages.
Since the equipment remains in the sports bag, extra space is not needed to dry the equipment. This also results in less conflict for those individuals who share the space in which the sports equipment would be dried by traditional methods.
Since the equipment remains in the sports bag, extra effort of spreading or hanging the equipment is not needed to dry the equipment.
Since the present invention allows for easy drying and scenting of sports equipment, the overall pleasure in participating in the sport for which the equipment is designed, is increased.
Since the equipment remains in the bag, and since it is scented during the proposed drying process, little to no foul smell is present outside the bag, quite unlike traditional drying methods.
Since the equipment can be easily dried quickly on a regular basis, the growth of bacteria on the sports equipment is greatly minimized
In preferred embodiments, the blower fan would have an on-off switch and a timer. In preferred embodiments, the fan does not have a heating function, as heat drying may degrade sports equipment, especially parts made of leather. However a low heating action which does not excessively heat the equipment may also be possible.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
FIG. 1 is a vertical cross-sectional view through a sporting equipment bag according to the present invention.
FIG. 2 is a vertical cross-sectional view through the fan and mounting ring of FIG. 1 on an enlarged scale.
FIG. 3 is a front elevational view of the mounting ring of FIG. 1 .
FIG. 4 is a rear elevational view of the mounting ring of FIG. 1 .
FIG. 5 is a front elevational view of the fan housing of FIG. 1 .
FIG. 6 is a rear elevational view of the fan housing of FIG. 1 .
FIG. 7 is a cross-sectional view on an enlarged scale of the scent dispensing housing of the fan housing of FIG. 1 .
DETAILED DESCRIPTION
A sports equipment bag is shown in FIG. 1 as indicated at 10 for receiving sports equipment schematically indicated at 11 within the bag for transportation and storage. The bag includes a bottom wall 12 which has a stiffener plate 13 so the bottom can rest upon the floor or other support surface with the sports equipment resting on the bottom in loose or random arrangement within the bag. The bag includes side walls 14 and a top 15 . At the top 15 is provided one or more handles 16 by which the bag can be carried. Adjacent or at the top 15 is provided an opening 17 with a closure member in the form of a zipper by which the opening can be opened for insertion and removal of the sporting equipment and the closure member reclosed to enclose the sporting equipment.
While the bag is shown generally rectangular, in most cases the bag is relatively elongate so as to define two of the side walls 14 as end walls 18 and 19 with the handle 16 having ends at or adjacent the end walls 18 and 19 so that the bag is carried longitudinally.
The sporting equipment generally may include bulky items such as helmets, skates, pads, boots and gloves all of which are relatively bulky and thick so that they cannot be readily washed and/or tumble dried.
In the end wall 18 is provided an opening 20 which is cut into the fabric of the end wall so as to form a circular opening in which the fabric is removed. At the end wall 19 is provided a similar circular opening 21 cut in the fabric forming the end wall 19 .
Each of the openings 20 and 21 is filled by a rigid plastics mounting member 22 which is clamped to the edge of the fabric surrounding the opening 20 , 21 and spans the opening so as to provide a closure member for the opening.
The mounting members 22 are identical in the arrangement as shown so that each is manufactured from the same parts and each can operate interchangeably with the other. This arrangement is preferred to minimize the number of parts manufactured but it will be appreciated that only one of the mounting members cooperates, at one time, with a fan 23 which is attached to the selected mounting member so as to support the fan at the end of the bag.
The mounting member comprises an outside ring 24 and an inside ring 25 so that the outside ring is mounted on the outside surface of the bag wall and the inside ring is mounted on the inside surface of the bag wall. The inside and outside rings provide matching abutting clamping elements 26 and 27 which are annular in shape and which grasp the edge portion of the fabric at the opening. The clamping elements include rings projecting outwardly from the face of the clamping element which cooperate with recesses in the other of the clamping elements so that the fabric is clamped between the rings and recesses to be held in place around the full periphery of the opening.
The outside ring 24 has a circular opening 27 which is open and allows access to the interior of the inside ring 25 through the opening 27 . The inside ring 25 includes a screen 28 spanning the opening with a screen having a plurality of slot shaped openings 29 which extend generally radially from a central closed area 30 to an outer edge 31 adjacent to but spaced inwardly from the inner edge of the outside ring 27 . The slot shaped openings 29 allow the penetration of air from the exterior through the opening 27 into the interior of the bag or vice versa. The screen 28 is curved so as to define a convex surface facing inwardly into the bag and a concave surface facing outwardly of the bag. The two portions of the mounting ring are clamped together by screws 32 A.
The outside ring 24 as shown in FIG. 3 includes a multi-lobed (in the example three lobes) bayonet receptacle 32 for receiving the male lobes 33 on the peripheral edge of the fan housing 23 as shown in FIG. 5 . Thus the fan housing can be mounted on either on of the mounting rings 22 and is attached simply by aligning the male lobes 33 with the female receptacles 32 and by rotating the housing so that the male lobes move behind shoulders 34 of the ring 24 to lock the lobes 33 in place on the ring 24 .
The fan 23 includes a housing 35 formed by a front piece 36 and a rear piece 37 which are clamped together by screw fasteners 38 .
The front portion 36 forms a domed convex shape facing forwardly of the front portion 36 so that it can closely follow the curvature of the concave surface of the mounting ring. Behind the domed front face of the fan housing is provided a fan rotor 40 mounted on a central shaft 41 of a motor 42 . The fan rotor extends across the housing inside the front face so as to drive air through the housing outwardly through the front face to pass through the openings 29 of the mounting ring. The front face of the fan housing therefore has slot shaped openings 44 shaped to match and align with the openings 29 in the mounting ring.
The motor 42 is mounted within a motor mount 45 carried within the interior of the housing 35 . The motor is arranged along a central axis of the fan housing behind the rotor 40 and in front of a central closed area of the rear portion 37 of the fan housing. The rear portion is also domed and includes a series of radially extending slots 47 extending outwardly from the central area to an outer periphery of the rear portion 37 .
A timer T and an on/off switch S are shown schematically in FIG. 5 and are located in the central closed area of the rear portion 37 for manual operation.
Centrally of the closed central area of the rear portion 37 is provided an air freshener or scent dispensing housing 50 which contains a block of scenting material 51 which releases scenting gases. The scenting material is contained within a slidable member 52 which can be manually pulled outwardly from the central area by a manually graspable handle 53 to open the scenting housing or the housing can be closed by pushing the handle 53 inwardly so that a cover 54 moves over the scenting block 51 to cover the scenting block. The cover 54 includes sides 55 with slots 56 in the side so that air flow into the fan housing is drawn from the area over the scenting block thus tending to pull gases discharged from the scenting block into the fan housing for discharge into the bag. The amount of scenting material can thus be controlled by pulling or pushing on the handle 53 so as to open and close the slots 56 from a fully closed position in which the cover 54 covers the scenting block to a fully open position in which the slots are pulled to their maximum open width allowing the maximum air freshener material to escape.
While the above describes a particular method of dispensing scent, it is proposed that various methods of providing a controlled scent release function is possible without materially departing from the intent of the present invention.
In operation, the user of the sporting equipment when returning from a sporting event simply leaves the equipment requiring drying within the bag resting in a loose or disordered collection within the bag sitting on the bottom of the bag. The fan housing is then taken from a storage location and inserted onto a selected one of the mounting rings.
If the user desires it, the scent cavity is checked and/or loaded with a scent block, and the scent controller is set to the desired level.
The fan is then actuated by the on/off switch and/or the timer so that air is pushed through the fan housing and through the screen section of the mounting ring into the interior of the bag. That air thus tends to inflate the bag with air beyond the air necessary for the inflation escaping through the other mounting ring to maintain the bag pressurized and air flow through the materials within the bag.
When the required drying time has elapsed, the fan housing can be removed from the bag and the bag used to carry the equipment to the new location for the next sporting event. The same fan housing can of course be used on other similar bags by other persons at the same location. The fan and the fan housing is driven by mains electricity from a supply cable (NOT SHOWN).
The mounting ring at one end is shown arranged so that the fan housing can be mounted by the end of the bag. However one of the rings may be mounted in the reverse direction with the domed screen facing outwardly so as to maximize the area available within the bag. This limits the mounting of the fan housing to the other concave end.
The mounting rings and the fan housing can be readily attached to a conventional sporting equipment bag so there is no need for purchase of a special bag for use with the present invention. The conventional bag can therefore be modified simply by cutting the necessary openings at each end and by attaching the mounting rings. In practice, therefore, the mounting rings and the fan can be sold separately as items to be used as required. Thus a user could purchase additional mounting rings for additional bags which would then be used with a single fan housing which would be moved from bag to bag as required. A family having multiple bags could therefore use a single fan housing and would purchase only the single fan housing to cooperate with multiple mounting rings.
In an alternative arrangement (not shown) the inlet opening can be formed of fabric in a specially designed bag where the opening preferably has a closure around the opening which allows it to be clamped around the lip or concave outer surface of the fan. Thus it may include an elastically pulled lip sticking out from the outer edge of a fabric mesh cover to engage over the fan, or may include a draw string in a sleeve at the edge of the lip. Thus the fan is held in place firmly at the end of the bag and the bag can expand under air pressure to allow drying throughout the equipment.
The equipment is transported in the same bag simply by disconnecting the fan and picking up the bag by the handles. There is no need to remove or handle the equipment before or after drying. Surprisingly, the bag which is substantially closed apart from the inlet and a similarly sized outlet, causes pressure and air flow within the bag to cause the drying air to permeate throughout the equipment, even into skate boots.
A particularly important discovery has been made in the development of the present invention. It was expected that the present invention would not work very well because sports equipment is often densely packed within a sports bag. The question was how well could room-temperature forced air dry very wet sports equipment which was tightly packed? Also, how could fresh air be introduced into cavities such as the inside of hockey skates and the like?
As experiments showed, it appears that the pressure created by the fan, (the bag puffs up quite noticeably) allows air to be “forced” throughout the whole interior of the bag, and throughout all of the equipment, almost regardless of how tightly packed they were.
It is preferred not to use a heater in the fan because, in practice, in addition to the added cost to manufacture the blower fan, the life span of some sports equipment decreases when dried with heat and drying occurs quite rapidly without heated air.
It must be noted that many placement options for the openings on the bag, the size of the fan, and the placement of the air freshener and its pocket, the shape and position of the fan/fan housing, the type of fan blade and motor, the shape, size, and placement of the connecting apparatus can be made without materially departing from the intent of the present invention. For example, the connecting apparatus could be friction fit like a vacuum cleaner hose, slide fit, snap on, etc.
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An apparatus and method is provided for drying and/or scenting sports equipment and the like. A sports bag is designed such that it has two openings which are covered by a mesh fabric or a rigid plastic screen. One opening is used to receive a blower fan engaged onto the mounting at the opening. The other opening is used to allow air to escape. Wet and/or foul smelling sports equipment is placed into the sports bag. An air freshener is inserted into a pocket located in the blower fan housing, or near to the opening of the intake opening of the sports bag. The fan is turned on (with or without a timer). In a relatively short period of time the sports equipment is dry, with little effort required or foul odor released outside the sports bag.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/610,680, filed Sep. 17, 2004 and entitled QUICK CONNECT COUPLING. The subject matter of this application is incorporated herein by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to flexible hose couplings. More particularly, it relates to a novel and improved quick connect hose couplings. Specifically, it relates to an improved push-to-connect and quick to disconnect flexible hose coupling.
[0004] 2. Description of the Prior Art
[0005] Quick connect couplings are known. In such couplings a port adapter may include the female portion or port and be pre-assembled on an associated fixture, machine or equipment or the female portion or port may be machined as part of associated fixtures, machinery or equipment. The hose connection or male portion or hose stem, including a hose insert portion and a ferrule, are attached to an open end of the hose to be connected to the fixture, machinery or equipment. The hose stem portion has a hose insert portion, which is inserted into the open end of the hose. The ferrule is then compressed about the hose end containing the insert causing all portions to be permanently affixed. Merely pressing the hose connection portion into the female portion or port subsequently completes the hose connection. Such quick connect couplings are particularly desirable when the hose must be connected in a location which is not readily accessible since it eliminates the need for starting the threads and the danger of cross threading and eliminates the need to use a related tool which might not fit in the available space. Since the port adapter may be threaded into place as a pre-assembly operation, or the port preexisting in the associated fixture, machine or equipment, it is easy to insure that the port is proper and ready. Further, the time of assembly and, in turn, the assembly costs are reduced.
[0006] Historically, the considerations that have driven the design of such couplings have included complexity of port design, effecting machineability, complexity of stem design, complexity and location of sealing elements such as o-rings or other shape of seals, complexity and location of locking components such as clips of various shapes, total number of components needed to complete the coupling, and interplay of the geometry of the port and the stem. All of these have greatly affected the cost of producing such couplings which impacts greatly upon their economic viability.
[0007] It has also been important to ensure that such couplings can be used safely and reliably. Obviously, one of the primary purposes of such couplings is to provide a long lasting leak-free connection. However, over time, increasing emphasis has been placed upon safety. The quick disconnect characteristic of such couplings necessarily give rise to a greater opportunity for inadvertent and sudden disconnects, with grave results. This is particularly true in the environments where use of such couplings is especially appealing. These include industrial or heavy machinery locations where installations of fluid connections are numerous, dense, and almost inaccessible, having movement of many hard and heavy objects nearby, including the fixtures upon which the couplings are often attached. Unexpected impacts upon quick to disconnect couplings or maintenance in such difficult quarters can increase the likelihood of inadvertent disconnects. Inadvertent disconnects on pressurized systems can lead to damaged or broken machines, destroyed premises, severe injuries to maintenance or other workers, or even death, such as through unexpected machinery movement or spray of very hot fluids at high pressure.
[0008] One example of a push to connect and quick to disconnect coupling can be found in U.S. Pat. No. 3,773,360 to Timbers, which is incorporated herein by this reference. It appears to be an attempt to provide both straight-forward push to connect and quick to disconnect processes while simplifying port and stem design to contain cost. Timbers '360 discloses the advantage of a simple port design where no sealing or locking components or clips are integral. However, the disclosed stem is more complex including all sealing and locking components. Further, the locking component is intricate and relatively complex. Significantly, the disclosed coupling requires an additional component, or stop member, to make the coupling resistant to inadvertent disconnection. The complexity and additional components would increase the cost of the coupling.
[0009] The coupling of Timbers '360 completes its fluid connection by simply pressing the male portion into the female portion. With the stop member removed, the coupling is disconnected by additional insertion of the male portion into the female portion into closer engagement. This causes the port to compress the locking component. The unique and intricate shape of the locking component then allows it to grab unto the stem and stay compressed such that its locking function is deactivated. The two portions are then separated.
[0010] It was apparently contemplated that the coupling of Timbers would be inadvertently disconnected too easily to be safe in many environments. Accordingly, the stop member was included in the disclosure. The stop member interferes with the male and female portions being pressed into closer engagement by filling space between the female and male portions. It would appear that the coupling with the stop member in place is resistant to inadvertent disconnection.
[0011] However, both the use and shape of the stop member leaves substantial opportunity for the coupling to experience disastrous inadvertent disconnection. First, there is no way to ensure that the stop member will be properly installed on the coupling during the entire time of its deployment. The stop member could be absent from the beginning or removed at any time during the life of the coupling leaving no tell-tale sign that anything is amiss. In such a condition the coupling would no longer be resistant to inadvertent disconnection. Second, the disclosed shape of the stop member includes a loop that extends radially away from the coupling. In the environments described above as those where the use of a quick to connect and quick to disconnect coupling is especially appealing, the loop would be subject to gathering debris or other being hooked by moving objects. This gives rise to substantial opportunity for the stop member to be stripped from the coupling. Once again, the coupling would no longer be resistant to inadvertent disconnection.
[0012] Safety is also compromised by the existence of such a rigid loop in many industrial or heavy machinery environments. It can be a direct source of damage or injury through the entanglement of debris, tools, clothing, hair or fingers. Further, it is not inconsequential that every time the coupling is to be disconnected, the metal loop, comprising the stop member, is removed to become lost as hazardous debris.
[0013] Accordingly, there remains the need for a quick to connect and quick to disconnect coupling having simplified design for economic viability, but more importantly, exhibiting greatly enhanced safety by being highly resistant to inadvertent disconnection without relying on human intervention to ensure all safety components are present upon the coupling, not having dangerous external shapes, and not adding to the opportunity for distribution of dangerous debris.
SUMMARY OF THE INVENTION
[0014] The present invention has as an object the provision of a quick connect and quick to disconnect hose coupling with an improvement in safety while retaining economical production and the benefits of such couplings.
[0015] The present invention is an improved quick to connect and quick to disconnect fluid coupling of the type having a clip, a male portion having an annular groove adapted to receive the clip, a female portion, and a sealing element. It is improved by the female portion having a dual function frustoconical portion adapted to compress the sealing element during joinder of the male portion with the female portion as well as to compress the clip into the annular groove in preparation of separating the male portion from the female portion. Further, a sleeve is slideably placed about the male portion and adapted to capture the clip compressed within the annular groove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are incorporated in and form part of the specification in which like numerals designate like parts, illustrate preferred embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings:
[0017] FIG. 1 is an elevation, with one quarter cut-away, of a preferred embodiment decoupled or disconnected;
[0018] FIG. 2 is an elevation, with one quarter cut-away, of a preferred embodiment during coupling operation (insertion);
[0019] FIG. 3 is an elevation, with one quarter cut-away, of a preferred embodiment upon coupling;
[0020] FIG. 4 is an elevation, with one quarter cut-away, of a preferred embodiment prepatory to decoupling or disconnection operation;
[0021] FIG. 5 is an exploded detail, from FIG. 4 ;
[0022] FIG. 6 is a plan view of a locking element in the simplified form of a snap-ring;
[0023] FIG. 7 is an elevation of a disconnect tool; and,
[0024] FIG. 8 is a plan view of a disconnect tool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Referring to FIG. 1 , a preferred embodiment of this quick connect coupling 1 of the instant invention includes female portion or port 10 and hose stem 12 . The female portion or port 10 is illustrated as part of an adapter 14 having threads 16 and formed with wrenching flats 18 , as one contemplated embodiment and for convenience of illustration. Commonly, port 10 is expected to be machined into the body of a fixture, machine or equipment not depicted. For those instances where port 10 is formed into an adapter 14 , adapter 14 provides the base for port 10 . For those instances where port 10 is formed into a fixture, machine or equipment, these provide the base. Port 10 has an interior surface 20 defining an inlet opening 22 , an outlet opening 24 , a fluid passage 26 , a first frustoconical ramp 28 , a first cylinder 30 , annular wall 32 , second frustoconical ramp 36 , and optionally second cylinder 34 . First frustoconical ramp 28 is a dual function ramp serving functions in both the connection and disconnection operations, to be described later. Second frustoconical ramp 36 is a lead-in ramp, significant to connection operation described later.
[0026] Still referring to FIG. 1 , hose stem 12 includes shaft 38 with a bore 40 having a stem inlet opening 42 and a stem outlet opening 44 . The shaft has an exterior surface 46 defining a first annular seal groove 48 , an annular clip groove 50 , an annular step groove 52 , a second annular seal groove 54 , sleeve abutment 55 , debris barrier 56 , hose stop 58 , hose insert 60 , and annular retaining groove 86 .
[0027] Hose insert 60 would be placed in an opened end of a hose, not depicted, that would carry the subject fluid. Insertion would normally progress until the end of the hose met the hose stop 58 . The hose would be affixed in common manner with a clamp or ferrule, not depicted.
[0028] First annular seal groove 48 carries first seal 62 and seal backing 64 . First seal 62 is a sealing element in the form of an o-ring. Seal backing 64 serves to increase the pressure at which the coupling can operate without fluid leaking past first seal 62 . Other available seal designs are also contemplated.
[0029] Clip 66 is a locking element in the simplified form of a snap-ring having gap 68 , depicted in FIG. 6 . Other clip shapes, such as with a square as opposed to a round cross section are also contemplated. Clip 66 is sized small enough that gap 68 must be enlarged to allow clip 66 to be large enough to pass over external surface 46 . However, clip 66 must also be large enough that gap 68 must be reduced to allow clip 66 to pass through first cylinder 30 . It is preferred that clip 66 is sized large enough that it completely fills the void created by first ramp 28 and optionally by second cylinder 34 . When so sized, it additionally acts as a wear buffer prolonging the life of coupling 1 by minimizing the wearing of port 10 . This feature is discussed more fully below. Gap 68 must be large enough to allow adequate reduction of clip 66 within clip groove 50 . Clip 66 is initially carried loosely in clip groove 50 .
[0030] Second annular seal groove 54 carries second seal 70 , also an o-ring. A capture sleeve 72 is mounted upon exterior surface 46 in slideable relation to stem 12 . Sleeve 72 has capture cylinder 74 and shoulder 76 . Capture cylinder 74 includes one or more press spots 88 which is the result of a crimping or pressing operation, and function as restraining detents. It is also contemplated that these restraining detents could be formed by machining or molding similar shapes into capture cylinder 74 . Press spots 88 are diminutive to allow sleeve 72 to be slid into place upon exterior surface 46 . Once so placed, the interaction of retaining groove 86 and press spot 88 restricts sleeve 72 from being removed from exterior surface 46 . When sleeve 72 is moved against sleeve abutment 55 , second seal 70 is captured under sleeve cylinder 74 . Clip 66 is not (see FIG. 2 ). When sleeve 72 is moved toward stem outlet 44 , as depicted in FIG. 1 , clip 66 is captured by sleeve cylinder 74 within clip groove 50 . Second seal 70 both seals the interface between exterior surface 46 and sleeve 72 against movement of contaminants, and provides friction to dampen movement of sleeve 72 . A third seal 80 is placed about capture cylinder 74 to span the gap between shoulder 76 and port 10 when coupling when coupling 1 is connected. Third seal 80 seals the interface of capture cylinder 74 and second ramp 36 against movement of contaminants.
[0031] Connection of coupling 1 is effected by inserting stem 12 into port 10 as depicted in a beginning phase as regards the relationship of stem 12 to port 10 in FIG. 2 . Note, in the preferred configuration in preparation of connection, clip 66 is captured by sleeve 72 , as depicted in FIG. 1 . The insertion continues to the position depicted in FIG. 3 . During this insertion, first seal 62 is guided by second ramp 36 into alignment with first cylinder 30 . First seal 62 is then compressed by second ramp 28 so that first seal 62 can move into a satisfactory sealing position between stem 12 and fluid passage 26 . It is because of this sealing relationship that fluid passage 26 can also be referred to as a sealing bore. Sleeve 72 is also guided by second ramp 36 into alignment with first cylinder 30 . As insertion progresses, sleeve lead-in 78 abuts first ramp 28 . After abutment of sleeve lead-in 78 and second ramp 28 , insertion of shaft 38 continues even though insertion of sleeve 72 is halted by this abutment. This results in sleeve 72 moving toward sleeve abutment 55 , relatively, and releasing clip 66 . Clip 66 is now captured only by passage 26 . Stem 12 is then retracted to the point depicted in FIG. 3 , where clip 66 expands into the void left by first ramp 28 and optionally second cylinder 34 . Stem 12 and port 10 are now in axial locking relationship. If a force is applied to stem 12 to expel or pull it from port 10 , such as under the influences of fluid pressure or pulling upon stem 12 (“non-allowed separation”), clip 66 will be pressed into step groove 52 by wall 32 . Clip 66 will then be jammed between step groove 52 and wall 32 . Retraction of stem 12 from port 10 will not be allowed.
[0032] Repeated attempts for non-allowed separation of coupling 1 while in the axial locking relationship, would wear upon wall 32 , and clip groove 50 but for the sizing of clip 66 described earlier and the presence of step groove 52 . Sizing clip 66 largely enough to fit snugly in the void left by first ramp 28 and second cylinder 34 , causes clip 66 to provide the additional function of a protective insert. A smaller sizing would allow clip 66 to work against wall 32 under the influences of non-allowed separation, wearing the material in which port 10 is formed, which is commonly softer than the material from which clip 66 is formed. The addition of step groove 52 causes the wear to occur in an orderly manner that gives indication of wear, by stem 12 seating in a less inserted manner in port 10 when in axial locking relationship, without a catstrophic failure of coupling 1 .
[0033] Capture cylinder 74 of sleeve 72 fills the space between external surface 46 and first cylinder 30 , stabilizing stem 12 against lateral movement in relation to port 10 . Accordingly, first cylinder 30 can be referred to as a stabilizing bore.
[0034] It is contemplated that insertion could be accomplished from a beginning point depicted in FIG. 2 and with capture sleeve 72 abutting sleeve abutment 55 . In this configuration clip 66 is not captured by sleeve 72 prior to connection. However, this increases the force required for connection. In this instance, insertion forces would include not only the force necessary to compress first seal 62 by second ramp 36 and by first ramp 28 in sequence, but the additional force necessary to compress clip 66 by second ramp 36 . The force required to compress clip 66 by second ramp 36 can be substantial. By contrast, it can be seen that connection utilizing the preferred configuration where clip 66 is captured by capture sleeve 72 requires substantially lees insertion force.
[0035] Disconnection of coupling is effected by first increasing the insertion of stem 12 into port 10 as depicted by the arrow in FIG. 4 . FIGS. 4 and 5 depict an intermediate position. First ramp 28 displaces clip 66 from step groove 52 toward clip groove 50 and then compresses clip 66 into clip groove 50 . During this operation first ramp 28 can be regarded as a disconnection ramp. Insertion continues until sleeve lead-in 78 abuts first ramp 28 , and clip 66 is compressed to a size that fits within passage 26 . Sleeve 72 is then axially moved to the position depicted in FIG. 1 , in relation to stem 12 to capture clip 66 . This is effected, not by moving sleeve 72 in the direction of the arrow, but rather by holding it steady while shaft 38 is retracted opposite of the direction indicted by the arrow. In practice this is accomplished by applying a wedging action between shoulder 76 and debris barrier 56 . A tool such as a blade screw driver can provide the wedging action by inserting the blade between shoulder 76 and debris barrier 56 and twisting. As the tool is of common design, it is not depicted. The special purpose tool 82 depicted in FIG. 7 can also provide the wedging action. Tines 84 are inserted between debris barrier 56 and shoulder 76 . Special purpose tool 82 is then rocked by applying pressure to handle 85 to provide the wedging action. Once clip 66 is thus captured under sleeve 72 , the jamming of clip 66 between wall 32 and step groove 52 cannot occur. The stem 12 becomes free to be disconnected from port 10 . Stem 12 is retracted from port 10 .
[0036] There are several subtle aspects to the instant invention that make it essentially fail safe against inadvertent disconnection. Primarily, disconnection requires a combination of actions that will not occur naturally. Merely pushing upon stem 12 has no effect upon causing disconnection. Even pushing upon both stem 12 and shoulder 76 will not lead to disconnection. Disconnection requires the concerted efforts of pushing stem 12 into port 10 and wedging shoulder 76 apart from debris barrier 56 . Further, urging capture cylinder toward the clip capture position without first increasing the insertion of stem 12 into port 10 is completely ineffective for two complementary reasons. One, sleeve lead-in 78 would actually tend to move clip 66 farther out of clip groove 50 as well as back toward step groove 52 . Two, step groove 52 is too shallow to allow clip 66 to be compressed to a size that fits within passage 26 . It can further be seen that sleeve shoulder 76 does not extend beyond the reach of debris barrier 56 . According, sleeve 72 does not lend itself to being simply grabbed and pushed into this clip capture position.
[0037] These subtleties allow the production of a quick to connect and quick to disconnect couplings that represents a dramatic leap forward in the safety of such couplings while keeping all of the desirable features. Further, they have led to such couplings without the additional hazards described in the Timbers '360 (i.e., hazards loops and potentially hazardous debris).
[0038] The foregoing description and illustrative embodiments of the present invention have been shown on the drawings and described in detail in varying modifications and alternative embodiments. It should be understood, however, that the foregoing description of the invention is exemplary only, and that the scope of the invention is to be limited only to the claims as interpreted in view of the prior art. Moreover, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.
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The present invention is an improved quick to connect and quick to disconnect fluid coupling of the type having a clip, a male portion having an annular groove adapted to receive the clip, a female portion, and a sealing element. It is improved by the female portion having a dual function frustoconical portion adapted to compress the sealing element during joinder of the male portion with the female portion as well as to compress the clip into the annular groove in preparation of separating the male portion from the female portion. Further, a sleeve is slideably placed about the male portion and adapted to capture the clip compressed within the annular groove.
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FIELD OF THE INVENTION
[0001] The invention relates generally to sputtering of materials. In particular, the invention relates to the a target containing multiple tiles of target material.
BACKGROUND ART
[0002] Sputtering, alternatively called physical vapor deposition (PVD), is widely used in the commercial fraction of semiconductor integrated circuits for depositing layers of metals and related materials. A typical DC magnetron plasma reactor 10 illustrated in cross section in FIG. 1 includes an electrically grounded vacuum chamber 12 to which a target 14 is vacuum sealed through an electrical isolator 16 . A DC power supply 18 negatively biases the target 14 with respect to the chamber 12 or a grounded sputter shield within the chamber 12 to excite an argon sputter working gas into a plasma. However, it is noted that RF sputtering is also known. The positively charged argon ions are attracted to the biased target 14 and sputter material from the target 14 onto a substrate 20 supported on a pedestal in opposition to the target 14 . A magnetron 24 positioned in back of the target projects a magnetic field parallel to the front face of the target 14 to trap electrons, thereby increasing the density of the plasma and increasing the sputtering rate. In modern sputter reactors, the magnetron may be small and be scanned about the back of the target 14 . Even a large magnetron may be scanned in order to improve the uniformity of erosion and deposition.
[0003] Although aluminum, titanium, and copper targets may be formed as a single integral member, targets for sputtering other materials such as molybdenum, chromium, and indium tin oxide (ITO) are more typically formed of a sputtering layer of the material to be sputtered coated onto or bonded to a target backing plate of less expensive and more readily machinable material.
[0004] Sputter reactors were largely developed for sputtering onto substantially circular silicon wafers. Over the years, the size of silicon wafers has increased from 50 mm diameters to 300 mm. Sputtering targets or even their layers of sputtering material need to be somewhat larger to provide more uniform deposition across the wafer. Typically, wafer sputter targets are formed of a single circular member for some materials such as aluminum and copper or a single continuous sputter layer formed on a backing plate for more difficult materials.
[0005] In the early 1990's, sputter reactors were developed for thin film transistor (TFT) circuits formed on glass panels to be used for large displays, such as liquid crystal displays (LCDs) for use as computer monitors or television screens. The technology was later applied to other types of displays, such as plasma displays and organic semiconductors, and on other panel compositions, such as plastic and polymer. Some of the early reactors were designed for panels having a size of about 400 mm×600 mm. It was generally considered infeasible to form such large targets with a single continuous sputter layer. Instead, multiple tiles of sputtering materials are separately bonded to a single target backing plate. In the original sizes of flat panel targets, the tiles could be made big enough to extend across the short direction of the target so that the tiles form a one-dimensional array on the backing plate.
[0006] Because of the increasing sizes of flat panel displays being produced and the economy of scale realized when multiple displays are fabricated on a single glass panel and thereafter diced, the size of the panels has been continually increasing. Flat panel fabrication equipment is commercially available for sputtering onto panels having a minimum size of 1.8 m and equipment is being contemplated for panels having sizes of 2 m×2 m and even larger. For such large targets, a two-dimensional tile arrangement illustrated in plan view in FIG. 2 may become necessary. Rectangular target tiles 30 are arranged in a rectangular array and bonded to a target backing plate 32 .
[0007] As shown in the plan view of FIG. 2 , a substantially rectangular target 30 includes rectangular target tiles 32 arranged in a rectangular array and bonded to a target backing plate 34 . The tile size depends on a number of factors including ease of fabricating the tiles and they may number 4×5, but the tiles 30 may be of substantial size, for example 75 mm×90 mm, such that a 3×3 array is required for a larger panel. The number of tiles in the tile array may be even greater if the target material is difficult to work with, such as chromium or molybdenum. The illustrated target backing plate 34 is generally rectangularly shaped to conform to the shape and size of the panel being sputter coated but its corners 36 are rounded to conform to the chamber body supporting it and it includes an extension 38 from the chamber body containing an electrical terminal for powering the target and pipe couplings for the cooling fluid used to cool the target 30 . As illustrated in cross section in FIG. 3 , the target backing plate 34 for flat panel sputtering is typically formed from two metal plates 42 , 44 , for example, of titanium welded or otherwise bonded together. One of the plates 42 , 44 is formed with linear cooling channels 46 through which the cooling fluid circulates. This backing plate 34 is more complex than the usual backing plate for wafer processing since, for the very large panel sizes, it is desired to provide a backside vacuum chamber rather than the usual cooling bath so as to minimize the differential pressure across the very large target 30 .
[0008] The tiles 32 are bonded to the backing plate 34 on its chamber side with a gap 48 possibly formed between the tiles 32 . Typically, the tiles 32 have a parallelopiped shape with perpendicular corners with the possible exception of beveled edges at the periphery of the tile array. The gap 32 is intended to satisfy fabricational variations and may be between 0 and 0.5 mm. Neighboring tiles 32 may directly abut but should not force each other. On the other hand, the width of the gap 48 should be no more than the plasma dark space, which generally corresponds to the plasma sheath thickness and is generally somewhat greater than about 0.5 mm for the usual pressures of argon working gas. Plasmas cannot form in spaces having minimum distances of less than the plasma dark space. As a result, the underlying titanium backing plate 34 is not sputtered while the tiles 32 are being sputtered.
[0009] Returning to FIG. 2 , the tiles 32 are arranged within a rectangular outline 40 conforming approximately to the area of the target 30 desired to be sputtered or somewhat greater. The magnetron 24 of FIG. 1 is scanned with this outline 40 . Shields or other means are used to prevent the untiled surface of the backing plate 34 from being exposed to high-density plasma and be thereby sputtered. Clearly sputtering a titanium backing plate 34 supporting molydenum or other tiles is not desired. Even if the backing plate 34 is composed of the same material as the target tiles 32 , sputtering of the backing plate 34 is not desired. The backing plate 34 is a complex structure and it is desired to refurbish it after one set of tiles 32 have been exhausted and to use it for a fresh set of tiles 32 . Any sputtering of the backing plate 34 should be avoided.
[0010] The rectangular tile arrangement of FIG. 2 presents difficulties with increases in the panel size. There are several processes available for bonding target tiles to backing plates. One popular process illustrated in FIG. 4 includes an apparatus comprising two heating tables 60 , 62 . The tiles 32 are placed on one table 60 with their sputtering face oriented downwards. Each tile 32 is painted on its backside with a coating 64 of indium. The heating table 60 heats the coated tiles 32 to about 200° C., far above indium's melting point of 156° C. so that indium wets to the tiles 32 and forms a uniform molten layer. Similarly, the backing plate 34 is placed on the other heating table 62 and is painted with an indium coating 66 and is heated to about 200° C. With all indium coatings 64 , 66 in their molten state, the tiles 32 are removed from the first table 60 , inverted, and placed on top of the backing plate 34 with the melted indium coatings 64 , 66 facing each other and the sputtering faces oriented upwards. Upon cooling, the indium solidifies and bonds the tiles 32 to the backing plate 34 .
[0011] The transfer operation must be performed quickly enough that the indium coating 64 on the tiles 32 does not solidify during transfer. For smaller targets, the transferring could be done manually. However, with the target and tiles becoming increasingly larger, a transfer fixture grasps the edges of the tiles, and a crane lifts the fixture and moves it to the second table.
[0012] Such large mechanical structures are not easily manipulated to provide the desired degree of alignment, specifically, the bonded tiles being separated by no more than 0.5 mm. Instead, as illustrated for a corner area 40 between four tiles 32 in the plan view of FIG. 5 , the four tiles 32 arranged in a rectangular array tend to slide along each other and be misaligned with different sizes for the inter-tile gaps 48 . More importantly, an interstix 72 between the corners of the four tiles may become much larger than intended. By an interstix is meant a point or space at the interfaces between three or more tiles so that the term does not include the line between two tiles. Even a well defined interstix 72 presents the greatest gap between tiles 32 . As a result, the widest point of the interstix 72 for misaligned tiles 32 may become larger than the plasma dark space, e.g., 1 mm, so that the plasma may propagate towards the backing plate 34 . If the gap is only slight lrager than the plasma dark space, the plasma state in the gap may be unsteady and result in intermittent arcing. Even if the arcing is confined to tile material, the arc is likely to ablate particles of the target material rather than atoms and create contaminant particles. If the plasma reaches the backing plate, it will be sputtered. Plate sputtering will introduce material contamination if the tiles and backing plate are of different materials. Furthermore, plate sputtering will make it difficult to reuse the backing plate for a refurbished target. Even if the plasma does not immediately reach the backing plate, an oversized interstix 72 allows the plasma to sputter the sides of the tiles 32 facing the interstix 72 . The side sputtering will further enlarge the interstix 72 and worsen the situation of plate sputtering.
[0013] A similar problem arises from the differential thermal expansion between the materials of the target tiles and the backing plate. When the bonded assembly is cooled to room temperature, the differential thermal expansion is likely to cause the assembly to bow. Because of the softness of solid indium, the bow can be pressed out of the bonded assembly. However, the pressing is a generally uncontrolled process and the tiles may slide relative to each other during the pressing to create the undesired tile arrangement of FIG. 5 .
[0014] Techniques have been developed to bond tiles to backing plates with a conductive elastomer that can be applied at a much lower temperature. Such bonding services are available from Thermal Conductive Bonding, Inc. of San Jose, Calif. Nonetheless, elastomeric bonding does not completely eliminate the misalignment problem with larger array of target tiles.
SUMMARY OF THE INVENTION
[0015] A target, particularly useful as a rectangular target, includes rectangular target tiles which are bonded to a target backing plate in a non-rectangular two-dimension array.
[0016] The rectangular tiles may be arranged in staggered rows such that only three tiles meet at an interstix and only two of those tiles have acute corners adjacent to the interstix. In one embodiment of the row arrangement, one row may include only plural whole tiles while a neighboring row has one less whole tile and two half tiles on the ends. In another embodiment of the row arrangement, all rows include the same number of whole tiles and one partial tile with the partial tiles being disposed on opposed ends of neighboring rows.
[0017] The rectangular tiles may alternatively be arranged in a herringbone or zig-zag pattern of whole rectangular tiles having a 1:2 size ratio and square tiles disposed on the periphery of the rectangular outline.
[0018] Alternatively, the tiles may be hexagonally shaped and arranged in a close-packed structure.
[0019] Yet further alternatively, the tiles may be triangularly shaped, preferably having isosceles shapes within the interior of the rectangular outline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic cross-sectional view of a conventional plasma sputter reactor.
[0021] FIG. 2 is a plan view of rectangular target of the prior art formed from a two-dimensional array of target tiles.
[0022] FIG. 3 is a cross-sectional view of a conventional configuration of target tiles bonded to a target backing plate including cooling channels.
[0023] FIG. 4 is a schematic view illustrating a conventional method of bonding target tiles to a backing plate.
[0024] FIG. 5 is a plan view illustrating a problem with the conventional rectangular arrangement of target tiles.
[0025] FIG. 6 is a plan view of a first embodiment of the invention including rectangular target tiles arranged in staggered rows.
[0026] FIG. 7 is a plan view of a second embodiment including rectangular tiles arranged in staggered rows with partial end tiles of the same size arranged on opposing ends of neighboring rows.
[0027] FIG. 8 is a plan view of a third embodiment including rectangular tiles arranged in a herringbone or zig-zag pattern.
[0028] FIG. 9 is a plan view of a fourth embodiment including hexagonal tiles.
[0029] FIG. 10 is a plan view of a fifth embodiment including triangular tiles.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Targets made according to the invention avoid many of the problems of conventional targets composed of tiles arranged in a rectangular array. Instead, as illustrated in the plan view of FIG. 6 , a target 80 of one embodiment of the invention includes rectangular tiles 32 each of substantially the same composition at least on its sputtering face and arranged in staggered rows and bonded to the target backing plate 34 . In this embodiment, the tiles 32 of one row are offset in the row direction from the tiles 32 of the neighboring rows. In some of the rows, end tiles 82 have a length in the row direction that is only a fraction of the corresponding length of full tiles 32 . In this embodiment, it is preferred that the length of the end tiles 82 be one-half the full length less the desired size of the gap between tiles so that only two sizes of tiles 32 , 82 are needed. While the tiles 32 , 82 can still slide in the row direction during their transfer to and bonding with the backing plate 34 , movement in the perpendicular direction is quite limited. As a result, interstices 84 at the corners between tiles 32 , 82 are much less likely to grow to abnormally large sizes. Furthermore, each interstix 84 forms between three tiles 32 , 82 and only two of the tiles 32 , 82 present acute angles to the interstix 84 . Accordingly, plasma arcing is less severe than with four tiles presenting four acute angles, as in the prior art target 30 of FIG. 1 .
[0031] The target 80 contains some rows containing a number N of whole tiles 32 alternating with rows containing N−1 whole tiles 32 and two half tiles 82 . Within a factor that is a ratio of the number of rows and number of columns, the aspect ratio of the whole tiles 32 determines the aspect ratio of the useful target area covered by the tile 32 , 82 .
[0032] A closely related target 90 illustrated in plan view in FIG. 7 has rectangular tiles 92 arranged in rows all containing N full tiles 92 and one partial rectangular tile 94 . The partial tiles 94 are arranged on opposite ends of neighboring rows and may have the same length in the row direction so that only two sizes of tiles are required. The length of the partial tiles 94 in the row direction is not limited to one-half the corresponding length of the full tiles 92 . Even if the full tiles 92 are square, the aspect ratio of the useful area of the target can be nearly freely chosen by varying the row dimension of the partial tiles 94 .
[0033] In both the targets 80 , 90 , the full tiles 32 are arranged in a parallelogram arrangement of similarly oriented tiles 32 .
[0034] A target 100 of a third embodiment of the invention is illustrated in FIG. 8 has rectangular tiles arranged in a herringbone arrangement, alternatively called a zig-zag arrangement. Viewed in the orientation of FIG. 8 , the herringbone pattern includes tiles 102 having an 1:2 aspect ratio, taking into account any desired gap between the tiles 102 . In the herringbone pattern, the tiles 102 are arranged in both the vertical and horizontal directions with paths passing through the short dimension of a first tile on a first end, through the long dimension of a second tile, and then through the short dimension of a third tile on a second end opposite the first end of the second tile. Thereafter, the pattern repeats. Viewed along the direction of the diagonal passing from lower left to upper right, there are parallel chevron patterns along the diagonal of pairs of orthogonally arranged tiles 102 . The edges around the rectangular pattern require several half tiles 104 . Note that a whole tile 106 at the upper right corner replaces two half tiles of the precise herringbone pattern.
[0035] The herringbone pattern provides many interlocking corners and thus allows little slippage to accumulate. This rigidity is accomplished with only two sizes of tiles. However, there is very little flexibility in the aspect ratio of the tiles in the simple illustrated herringbone pattern so that the overall aspect ratio of the useful area of the target is constrained to ratios of small integers. The target aspect ratio can be more freely chosen if rectangularly shaped target tiles of nearly arbitrary aspect ratio are lined up on one of the edges of the herringbone pattern. (A similar edge row of differently sized tiles may be used with the other rectangular arrangements to more easily attain an arbitrary aspect ratio.) The herringbone pattern can be characterized as pairs of perpendicularly oriented 1:2 tiles arranged in an parallelogram pattern.
[0036] In all the rectangular embodiments described above with reference to FIGS. 6, 7 , and 8 , a tile in the interior of the two-dimensional array away from the periphery abuts along a line six other tiles, whether they be full or partial tiles in contrast to the four tiles abutted in the prior art rectangular arrangement of FIG. 1 .
[0037] All the previously described patterns involve rectangular tiles. In contrast, a target 110 illustrated in plan view in FIG. 9 includes regular hexagonal tiles 112 arranged in a hexagonal close packed structure, alternatively characterized as a rhombohedral pattern with one pair of sides aligned with the rectangular outline. It is not conventional to fabricate tiles in non-rectangular shapes. However, targets of many high-temperature metals are formed by sintering powders in a mold. The mold can be shaped in the required non-rectangular shape, in this embodiment a hexagonal shape. Fitting the hexagonal tiles 122 into a rectangular shape requires extra edge pieces. However, in the design of FIG. 9 , the edge pieces can be restricted to tiles of two shapes, trapezoidal tiles 114 along set of opposed edges, which are half hexagons, and pentagonal tiles 116 along the other set of opposed edges. Although the illustrated hexagons are regular, they may be stretched or shrunk along one opposed pair of sides with all interior corners maintained at 60°. Even with regular hexagons having a fixed aspect ratio, the length of the parallel sides of the pentagonal tiles 106 may be varied to provide more freedom in the overall target aspect ratio. The limitation to three sizes of tiles 112 , 114 , 116 is obtained when there are an odd number of rows in the illustrated orientation of an odd number of abutting hexagon tiles 112 , one of which may be split into two trapezoidal tiles 114 for the edges. The hexagonal arrangement produces interstices 118 abutting three tiles 112 (including edge tiles 114 , 116 as appropriate). Each of the abutting tiles abuts at corners having an exterior obtuse angle of 120°. Similarly to the rectangular patterns of the invention, each hexagonal tile 112 in the interior of the arrangement abuts along a line six other tiles, whether they be full or partial tiles.
[0038] The rectangular and hexagonal tiles described above have interior angles of 90° and 60° respectively. It is possible to modify these shapes to more oblique shapes. As long as the opposed sides of the tiles are parallel, they can be close packed. However, such oblique shapes require additional edge pieces.
[0039] Another target 120 illustrated in plan view in FIG. 10 includes triangular tiles. In the illustrated embodiment, each row includes alternating triangular tiles 122 , 124 of the same shape of an isosceles triangle but with inverted orientations with respect to the perpendicular of the horizontally illustrated row direction. Two right triangular tiles 126 are disposed at the end of the rows to provide the desired overall rectangular shape. If there are matched pairs of tiles 122 , 124 in each row, that is, N of each, then the right triangular end tiles 128 have the same shape even if their tops and bottoms need to be differentiated. As a result, only two sizes of tiles 122 , 124 and 126 are required. The vertically oriented vertex of one isosceles tile 124 , 126 abuts the base of another similar oriented isosceles tile 124 , 126 so that interior interstices 128 are bordered by three acute apexes and one flat side of four respective tiles 124 , 126 . If the isosceles triangles of the tiles 124 , 126 are equilateral triangles, the minimum apex angle is increased and the perimeter-to-area ratio decreased. However, an equilateral design provides little flexibility in overall aspect ratio of the target while a more general isosceles design allows different base-to-side ratios in the triangles. In the illustrated triangular arrangement, each tile 122 or 124 at the interior of the pattern abuts along a line four other triangular tiles, whether they be full or partial. It may be desirable to line one edge of the triangular array, whether isosceles or equilateral, with rectangular tiles of arbitrary aspect ratio to thereby allow an arbitrary target aspect ratio.
[0040] The illustrated triangular arrangement can be characterized as a rectangular arrangement of non-rectangular elements although non-rectangular arrangements are possible. In any case, all the embodiments described above include a two-dimensional array of tiles arranged and bonded to the backing plate such that the edges of the tiles do not conform to a rectangular two-dimensional grid, as do the tiles of the prior art arrangement of FIG. 2 .
[0041] Other triangular shapes and staggering patterns are possible, but the isoceles design of FIG. 10 provides a large minimum apex angle and a small number of extra edge pieces.
[0042] The invention is useful not only for refractory metal targets such as molybdenum, chromium, and tungsten as well as silicon, targets of which are difficult to fabricate in large sizes. Similarly, the invention is also useful for targets of more complex composition, such as indium tin oxide (ITO), which is typically sputtered from a target of a mixture of indium oxide and tin oxide in the presence of an oxygen ambient. Nonetheless, the invention is also useful for more common metals such as aluminum, copper, and titanium, particularly when a target backing plate is used which is intended to be refurbished. That is, the invention is not limited to the composition of the target The invention may further be applied to targets used in RF sputtering, such as insulating targets, as may be used for sputtering metal oxides. A magnetron is not essential for the invention. Furthermore, the invention can be applied to round targets although a large variety of edge pieces are required.
[0043] Although the invention has been described on the basis of planar bodies having straight sides, it is understood that the edges may have cross-sections of more complexity, such as steps, as long as the overall shape is describable as rectangular, etc. Similarly, the corners of the shape may be somewhat rounded, either intentionally or unintentionally.
[0044] The invention is most useful for large rectangular targets having minimum dimensions of greater than 1.8 m. However, the invention is applicable to smaller targets for which tiling is still desired. Especially for smaller targets, the target backing plate may be simpler than the one illustrated and not include the cooling channels.
[0045] The invention thus provides less tile misalignment and improved sputtering performance with only a small increase in the complexity of the tiled target and its fabrication.
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A sputtering target, particularly for sputter depositing a target material onto large rectangular panels, in which a plurality of target tiles are bonded to a backing plate in a two-dimensional non-rectangular array such that the tiles meet at interstices of no more than three tile, thus locking the tiles against excessive misalignment during bonding. The rectangular tiles may be arranged in staggered rows or in a herringbone or zig-zag pattern. Hexagonal and triangular tiles also provide many of the advantages of the invention.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority from provisional application No. 60/161,692, filed Oct. 26, 1999 for “PIEZOELECTRIC IN-PLANE BIMORPH ON LOAD BEAM SUSPENSION-LEVEL MICROACTUATOR” by James Morgan Murphy, Richard August Budde, Markus E. Mangold, and Peter Crane.
BACKGROUND OF THE INVENTION
The present invention relates to a suspension-level microactuator having an improved stroke length. More particularly, it relates to a microactuator located in-plane along a suspension in a disc drive system and having an electroactive element to selectively move a transducing head radially with respect to a rotatable disc.
Disc drive systems include disc drive suspensions for supporting transducing heads over information tracks of a rotatable disc. Typically, suspensions include a load beam having a mounting region on a proximal end, a flexure on a distal end, a relatively rigid region adjacent to the flexure, and a spring region between the mounting region and the rigid region. An air bearing slider which supports the transducing head is mounted to the flexure. The mounting region is typically attached to a base plate for mounting the load beam to an actuator arm. A motor which is controlled by a servo control system rotates the actuator arm to position the transducing head over the desired information tracks on the disc. This type of suspension is used with both magnetic and non-magnetic discs.
In an effort to increase the storage capacity of hard disc drives, the density of concentric data tracks on magnetic discs continues to increase (i.e., the size of data tracks and radial spacing between the data tracks continues to decrease). Therefore, a corresponding improvement in the accuracy of the positioning system that locates the transducing head over a particular track is needed. Conventionally, the positioning system uses a single-stage, closed-loop feedback system in which a large-scale actuation motor, such as a voice coil motor, acts in response to a control signal based on position error information from the read head to radially position a head on a slider at the end of the actuator arm. This system is approaching the limit of its ability to follow the ever-narrower tracks and to reject the vibrations and disturbances present in the drive environment. This inability to follow the narrow tracks is due in large part to the significant length of structure between the voice coil motor and the head and the in-loop resonances which result from the structure. Thus, a high resolution head positioning mechanism is needed to accommodate the more densely spaced tracks.
One promising design for high resolution head positioning involves employing a high resolution microactuator in addition to the conventional low resolution actuator motor, thereby effecting head positioning through dual-stage actuation. Various microactuator designs have been considered to accomplish high resolution head positioning. These designs, however, have shortcomings that limited the effectiveness of the microactuator. Many designs increased the complexity of designing and assembling the existing components of the disc drive, while other designs were unable to achieve the force and bandwidth necessary to accommodate rapid track access. Therefore, the prior designs did not present ideal microactuator solutions.
The positioning of a transducing head through dual-stage actuation using electroactive elements has been disclosed in prior patent applications. One such application is U.S. patent application Ser. No. 09/311,086, filed May 13, 1999 by Budde et al. entitled “PIEZOELECTRIC MICROACTUATOR SUSPENSION ASSEMBLY WITH IMPROVED STROKE LENGTH,” which is assigned to Seagate Technology, Inc., the assignee of the present invention, and is hereby incorporated by reference. Another such application is U.S. patent application Ser. No. 09/553,220, filed on even date herewith by Boutaghou, Crane, Mangold, and Walter entitled “BENDING MICROACTUATOR HAVING A TWO-PIECE SUSPENSION DESIGN,” which is assigned to Seagate Technology, Inc., the assignee of the present invention, and is hereby incorporated by reference. There remains a need in the art, however, for an electroactive element microactuator design that provides efficient high resolution head positioning in a dual-stage actuation system, allows for a greater range of motion than current designs, has reduced in-loop resonances, and is easy to manufacture and install.
BRIEF SUMMARY OF THE INVENTION
The present invention is a microactuator for selectively altering a position of a transducing head carried by a slider, in a disc drive system, with respect to a track of a rotatable disc having a plurality of concentric tracks. The disk drive system includes an actuator arm. The microactuator includes a load beam attached to a distal end of the actuator arm. The load beam has a first section and a second section. A flexure is connected to the second section of the load beams for supporting the slider carrying the transducing head. A hinge is attached between the first section and the second section, the hinge being flexible to permit movement of the second section with respect to the first section in the general plane of the load beam. A bending motor is connected between the first section and the second section of the load beam along a longitudinal centerline of the load beam. The bending motor is deformable in response to a control signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a disc drive system including a microactuation system for positioning a transducing head over selected tracks of a rotating disc.
FIG. 2A is a top view of a microactuation system, shown in a neutral position, for use in a dual-stage disc drive actuation system for high resolution positioning of a transducing head according to the present invention.
FIG. 2B is a top view of the microactuation system of FIG. 2A, shown in a first actuated position, for use in a dual-stage disc drive actuation system for high resolution positioning of a transducing head according to the present invention.
FIG. 2C is a top view of the microactuation system of FIG. 2A, shown in a second actuated position, for use in a dual-stage disc drive actuation system for high resolution positioning of a transducing head according to the present invention.
FIG. 3 is a top perspective view of the microactuation system of FIG. 2 A.
FIG. 4 is a bottom perspective view of the microactuation system of FIG. 2 A.
FIG. 5 is a top perspective view of the microactuation system of FIG. 2A shown with the bending motor removed.
FIG. 6 is a top view of a portion of the microactuation system of FIG. 2 A.
FIG. 7A is a cross-sectional view of a bending motor according to a first embodiment of the present invention.
FIG. 7B is a cross-sectional view of a bending motor according to a second embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a perspective view of disc drive system 10 , as known in the prior art, for positioning a transducing head (not shown) over a selected track of a magnetic disc. The system 10 includes, as shown generally from left to right in FIG. 1, a voice coil motor (VCM) 12 , an actuator arm 14 , a suspension 16 , a flexure 18 , and a slider 20 . The slider 20 is connected to the distal end of the suspension 16 by the flexure 18 . The suspension 16 is connected to the actuator arm 14 which is coupled to the VCM 12 . As shown on the right side of FIG. 1, the system 10 includes a disc 22 having a multiplicity of tracks 24 that rotate about an axis 26 . During operation of the disc drive system 10 , the rotation of the disc 22 generates air movement which is encountered by the slider 20 . This air movement or windage acts to keep the slider 20 aloft a small distance above the surface of the disc 22 allowing the slider to “fly” above the surface of the disc 22 . Any wear associated with physical contact between the slider 20 and the disc 22 is thus minimized.
The flexure 18 provides a spring connection between the slider 20 and the suspension 16 . The flexure 18 is configured such that it allows the slider 20 to move in pitch and roll directions to compensate for fluctuations in the spinning surface of the disc 22 . Many different types of flexures 18 , also known as gimbals, are known to provide the spring connection allowing for pitch and roll movement of the slider 20 and can be used with the present invention. The VCM 12 is selectively operated to move the actuator arm 14 around an axis 28 , thereby moving the suspension 16 and positioning the transducing head (not shown) carried by the slider 20 between tracks 24 of the disc 22 . Proper positioning of the transducing head (not shown) is necessary for reading and writing of data on the concentric tracks 24 of the disc 22 . For a disc 22 having a high track density, however, the VCM 12 lacks sufficient resolution and frequency response to accurately position the transducing head (not shown) on the slider 20 over a selected track 24 of the disc 22 . Therefore, a higher resolution actuation device is used in combination with the VCM 12 .
FIGS. 2A-2C show three top views of a microactuation system 30 for use in a dual stage disc drive actuation system for high resolution positioning of a transducing head (not shown) according to the present invention. As shown from right to left in FIGS. 2A-2C, the microactuation system 30 includes a bending motor 32 and a load beam 34 . A mounting region 38 of the load beam 34 connects to a base plate (not shown) which connects to the actuator arm 14 . The bending motor 32 , the load beam 34 , and the base plate are all components of the suspension 16 (as shown in FIG. 1 ). As shown on the far right side in FIGS. 2A-2C, the distal end of the load beam 34 is coupled to the flexure 18 , which holds the slider 20 .
FIGS. 2A-2C when viewed together illustrate the general operation of the microactuation system 30 of the present invention. FIG. 2A shows the microactuation system 30 in a neutral position. As is apparent from FIG. 2A, in the neutral position the bending motor 32 is generally straight along its longitudinal axis. FIG. 2B shows the microactuation system 30 in a first actuated position in which the bending motor 32 is curved or bent to the left of the neutral position. FIG. 2C shown the microactuation system 30 in a second actuated position in which the bending motor 32 is curved or bent to the right of the neutral position. The amount of displacement of the slider 20 shown in FIG. 2 B and FIG. 2C is exaggerated for purposes of illustration. The bending of the bending motor 32 operates to cause a displacement of the slider 20 and thus the transducing head (not shown), which in turn causes an adjustment of the position of the transducing head (not shown) with respect to a selected track 24 of the disc 22 .
FIG. 3 shows a top perspective view of the microactuation system 30 of the present invention (absent the mounting region 38 ). As shown in FIG. 3, moving from left to right, or from a proximal end to a distal end, the load beam 34 includes two pre-load bend legs 40 a , 40 b and a head suspension 42 . The head suspension 42 is flexibly coupled to the mounting region 38 (shown in FIGS. 2A-2C) by the two pre-load bend legs 40 a , 40 b . The head suspension 42 includes a proximal section 44 and a distal section 46 separated by an air gap or a space 47 . The distal section 46 is connected to the proximal section 44 by two hinges 48 a and 48 b . The distal section 46 of the head suspension 42 supports the flexure 18 , which supports the slider 20 , which supports the transducing head (not shown).
As further shown in FIG. 3, the bending motor 32 is mounted to a top surface of the head suspension 42 in a plane generally parallel to the plane of the head suspension 42 . The bending motor 32 is mounted to the proximal section 44 and the distal section 46 of the head suspension 42 . In a preferred embodiment, the bending motor 32 is mounted to the head suspension 42 using an adhesive. The bending motor 32 can also be mechanically fastened to the head suspension 42 . The fastening of the bending motor 32 to the head suspension 42 is described in greater detail below with reference to FIG. 5 .
The configuration of the bending motor 32 with respect to the head suspension 42 has significant advantages. The configuration allows for the use of longer bending motors 32 , which allows for a greater stroke or cross-track deflection of the transducing head. Also, the bending motor 32 is supported by the head suspension 42 and the head suspension 42 acts to absorb the majority of shock loads applied to the slider 20 so that less force is transmitted through the bending motor 32 . This results in improved robustness and shock resistance. Also, the configuration of the present invention results in a stiffer structure, which increases the resonance frequencies. Finally, the placement of the bending motor 32 near the slider 20 and the transducing head results in decreased in-loop resonances and vibrations as there are fewer components between the bending motor 32 and the transducing head (which supplies the position error information). The significance of in-loop resonances is further detailed in the above-referenced copending U.S. patent application Ser. No. 09/553,220, by Boutaghou, Crane, Mangold, and Walter et al. entitled “BENDING MICROACTUATOR HAVING A TWO-PIECE SUSPENSION DESIGN.”
A bottom perspective view of the microactuation system 30 of the present invention is shown in FIG. 4, which more clearly illustrates the flexure 18 and the slider 20 mounted to a distal end of the head suspension 42 . FIG. 4 also shows the location of the transducing head 49 carried by the slider 20 .
FIG. 5 shows a top perspective view of the microactuation system 30 of the present invention with the bending motor 32 removed to reveal additional features of the head suspension 42 . As further shown in FIG. 5, the distal section 46 of the head suspension 42 includes two slots 50 a , 50 b and an adhesive region 52 , and the proximal section 44 includes, near a proximal end, an adhesive region 54 . The bending motor 32 is generally mounted to the proximal section 44 of the head suspension 42 at the adhesive region 54 and to the distal section 46 of the head suspension 42 at the adhesive region 52 . The slots 50 a and 50 b act to prevent the adhesive used to mount the bending motor 32 to the distal section 46 of the head suspension 42 from moving or wicking along the bending motor 32 . This, in turn, helps to maximize the effective length, or the area between attachment points, of the bending motor 32 . The present invention, by employing elements having increased effective lengths, has increased stroke or cross-track deflection of the transducing head.
FIG. 6 shows a top view of the hinge region of the head suspension 42 . As shown in FIG. 3, the proximal section 44 is rotatably coupled to the distal section 46 of the load beam 42 by hinges 48 a and 48 b . The hinges 48 a and 48 b are generally formed by bending the material of the head suspension 42 normal to the general plane of the head suspension 42 . This configuration provides increased compliance for rotation about a virtual pivot VP to facilitate rotation and displacement of the distal section 46 with respect to the proximal section 44 in a plane generally parallel to that of the disc 22 . At the same time, this configuration provides substantial stiffness to resist undesired movements and vibrations out of a plane generally parallel to the disc 22 . The location of the virtual pivot VP is generally identified by the intersection of two lines extending from and parallel to the two hinges 48 a , 48 b (as shown by the dashed lines in FIG. 3 ). In a preferred embodiment, the hinges 48 a , 48 b are configured such that the virtual pivot VP is located near a longitudinal and transverse center point of the bending motor 32 . One advantage of the configuration of the head suspension 42 is that the location of the two hinges 48 a , 48 b reduces deformation resulting from application of the preload force. Because the hinges 48 a , 48 b are located close to the point of application of the preload force, lower bending moments result.
The specific pivotal structures flexibly coupling the distal portion 46 of the head suspension 42 to the proximal portion 44 of the head suspension 42 shown in FIGS. 3-6 are intended to be exemplary only. Many other pivotal structures can also be used between the distal portion 46 and proximal portion 44 of the head suspension 42 . For example, the hinges 48 a , 48 b can be disposed at a variety of angles with respect to the longitudinal centerline of the head suspension 42 . Also, one or more appropriately sized beams can be used to connect the two portions 44 , 46 of the head suspension 42 . Other structures generally known to those of ordinary skill in the art can also be employed.
The bending motor 32 is a structural element operable as a bendable cantilever to alter the position of the distal section 46 with respect to the proximal section 44 of the head suspension 42 (as illustrated by the sequence of FIGS. 2 A- 2 C). By causing rotation and displacement of the distal section 46 of the head suspension 42 , the bending motor 32 effects high resolution positioning of the transducing head carried by the slider 20 . In a preferred embodiment the bending motor 32 is constructed from an electroactive material such as piezoelectrics, electroactive ceramics, electroactive polymers, or electrostrictive ceramics. In another preferred embodiment the bending motor 32 is constructed from thermoactive elements. The remainder of this disclosure will describe the preferred embodiment of the present invention employing piezoelectric elements such as zinc oxide (ZnO), lead zirconate titanate (PbZrTiO 3 , also known as PZT), aluminum nitride (AlN), or polyvinylidene fluoride (PVDF).
FIG. 7A shows a sectional view of a oppositely poled bending motor 60 , which represents a first preferred embodiment of the bending motor 32 described with reference to FIG. 3 . The view shown in FIG. 7A is a transverse cross-section taken across the width of the oppositely poled bending motor 60 . The oppositely poled bending motor 60 operates using a “single-ended” approach as further explained below. The oppositely poled bending motor 60 includes a bottom electrode 62 , a oppositely poled piezoelectric element 64 , and a top electrode 66 . The oppositely poled piezoelectric element 64 is divided generally along a longitudinal centerline into a first portion 68 (shown on the left side of FIG. 7A) and a second portion 70 (shown on the right side of FIG. 7 A). The oppositely poled piezoelectric element 64 is formed such that the first portion 68 and the second portion 70 have opposite poling. For example, the first portion 68 is poled in the direction of the arrow 72 , and the second portion 70 is poled in the direction of the arrow 74 .
During operation, an electric potential is applied to the bottom electrode 62 and the top electrode 66 . Generally, the bottom electrode 62 is connected to electrical ground, and the driving voltage is applied to the top electrode 66 . Alternatively, voltages of opposite polarities can be applied to the top electrode 66 and the bottom electrode 62 to create an overall potential between the electrodes greater than the voltage applied to either single electrode. The potential difference between the bottom electrode 62 and the top electrode 66 causes expansion or contraction of the first portion 68 and the second portion 70 of the oppositely poled piezoelectric element 64 . For example, if a positive voltage is applied to the top electrode 66 , the first portion 68 (poled in a positive direction) will contract in the direction normal to the electrodes 62 , 66 , which, in turn, will cause the first portion 68 to expand longitudinally (in the direction parallel to the electrodes 62 , 66 ). Conversely, the same positive voltage applied to the top electrode 66 will cause the second portion 70 to contract longitudinally.
The expansion of the first portion 68 and the concurrent contraction of the second portion 70 generates a bending moment in the piezoelectric element 64 in-plane. This moment results in a bending motion of the oppositely poled bending motor 60 , toward the right as illustrated in FIG. 2C, which will effect rotation and displacement of the distal section 46 with respect to the proximal section 44 of the head suspension 42 . This rotation and displacement of the distal section 46 will, in turn, cause movement of the transducing head carried by the slider 20 . The amount of bending of the oppositely poled bending motor 60 , and thus the amount of displacement of the transducing head, is precisely controlled by the magnitude of the voltages applied to the electrodes 62 , 66 . The direction of the bending motion is controlled by the polarity of the voltage applied to the electrodes 62 , 66 , and the amount of displacement is controlled by the magnitude of the voltages applied. The bending motion will occur in a direction toward the side that is contracting longitudinally.
FIG. 7B shows a sectional view of a uniformly poled bending motor 80 , which represents a second preferred embodiment of the bending motor 32 described with reference to FIG. 3 . The view shown in FIG. 7B is a transverse cross-section taken across the width of the uniformly poled bending motor 80 . The uniformly poled bending motor 80 operates using a “differential” approach as further explained below. The uniformly poled bending motor 80 includes a bottom electrode 82 , a piezoelectric element 84 , a first top electrode 86 , and a second top electrode 88 . The first top electrode 86 is deposited over the top surface of one longitudinal half of the piezoelectric element 84 , and the second top electrode 88 is placed over the other longitudinal half of the piezoelectric element 84 . The entire piezoelectric element 84 is poled in the direction of the arrow 90 .
During operation, an electric potential is applied to the bottom electrode 82 and the top electrodes 86 , 88 . Generally, the bottom electrode 82 is connected to electrical ground, and the driving voltage is applied to the top electrodes 86 , 88 . Alternatively, two bottom electrodes can be used, placed generally opposite the two top electrodes 86 , 88 , and a voltage can also be applied to the two bottom electrodes. The potential difference between the bottom electrode 82 and the top electrodes 86 , 88 causes expansion or contraction of the portion of the piezoelectric element 84 located between the respective top electrode and the bottom electrode. For example, if a positive voltage is applied to the first top electrode 86 , the portion of the piezoelectric element 84 located between the first top electrode 86 and the bottom electrode 82 will contract in the direction normal to the electrodes 82 , 86 , which, in turn, will cause the that portion to expand longitudinally (in the direction parallel to the electrodes 82 , 86 ). At the same time, a negative voltage is applied to the second top electrode 88 , which causes the portion of the piezoelectric element located between the second top electrode 88 and the bottom electrode 82 to contract longitudinally.
The expansion of the first portion and the concurrent contraction of the second portion generates a bending moment in the piezoelectric element 84 . This moment results in a bending motion of the uniformly poled bending motor 80 , toward the right as illustrated in FIG. 2C, which will effect rotation and displacement of the distal section 46 with respect to the proximal section 44 of the head suspension 42 . This rotation and displacement of the distal section 46 will, in turn, cause movement of the transducing head carried by the slider 20 . The amount of bending of the uniformly poled bending motor 80 , and thus the amount of displacement of the transducing head, is precisely controlled by the magnitude of the voltages applied to the electrodes 82 , 86 , 88 . The direction of the bending motion is controlled by the polarity of the voltages applied to the first top electrode 86 and the second top electrode 88 , and the amount of displacement is controlled by the magnitude of the voltage applied. The bending motion will occur in a direction toward the side that is contracting longitudinally.
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 microactuation system selectively alters a position of a transducing head carried by a slider in a disc drive system with respect to a track of a rotatable disk having a plurality of concentric tracks. The microactuation system includes a head suspension having a first portion and a second portion coupled by one or more flexible hinges. An electroactive element is attached to the first portion of the head suspension at one end and the second portion of the load beam at the other end. The electroactive element bends in response to a control signal applied thereto. The hinge is sufficiently compliant to permit movement of the first portion with respect to the second portion of the head suspension.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 USC 119(e) of provisional patent application No. 61/237,233, which was filed on Aug. 26, 2009, and which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to semiconductor circuits, and more specifically to a high voltage switch implemented in a low voltage semiconductor process.
BACKGROUND OF THE INVENTION
[0003] Advanced integrated circuit fabrication processes, such as CMOS can produce chips with low power consumption, high logic density and high speed of operation. However, these modern processes manufacture integrated circuits that operate at low voltages, due to the lowered breakdown voltages of the transistors that are fabricated. These low voltage IC's are difficult to interface with circuits operating at higher voltage levels, unless special processes are used that can produce low voltage and high voltage devices in the same IC, but these special processes can have disadvantages such as limited performance capabilities.
[0004] One particular area of technology using low voltage ICs, but required to interface to higher voltage circuits is implantable medical devices for the purpose of functional electrical stimulation (FES). Such devises stimulate nerve bundles with electrodes in close proximity to the nerve tissue. The ability to process high voltage signals using high voltage tolerant circuits such as analog switches, with integrated circuits built using low voltage advanced CMOS processes, is highly desirable.
SUMMARY OF THE INVENTION
[0005] A high voltage analog switch operable by a binary signal is implemented in a low voltage semiconductor process. The binary signal is converted to control signals with fixed voltage levels: ground and supply voltages Vdd and 2×Vdd. An additional control voltage is used which is equal to the switch input voltage level plus an added offset voltage. The switch has three parallel circuit paths, with each path comprising at least three series connected MOSFET transistors. The control signals are selectively applied to the gates of the transistors to control the switch and selectively turn on or turn off each of the three circuit paths depending on the input voltage range, so that the breakdown voltage of any of the transistors is never exceeded in any mode of operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a block diagram of a high voltage switch according to an embodiment of the present invention.
[0007] FIG. 2 shows an exemplary table of relative voltage levels generated within a switch controller for the high voltage switch of FIG. 1 .
[0008] FIG. 3 shows a circuit diagram of an exemplary switch module for the high voltage switch of FIG. 1 .
[0009] FIG. 4 shows a table of on/off states for the transistors of the switch module of FIG. 3 .
[0010] FIG. 5 shows a table of gate voltages for the switched transistors of the switch module of FIG. 3 .
[0011] FIG. 6 shows a table of node voltages within the switch module of FIG. 3 .
[0012] FIG. 7 shows a circuit diagram for an alternate embodiment of the high voltage switch of the present invention.
DETAILED DESCRIPTION
[0013] FIG. 1 shows a block diagram of a high voltage analog switch (HVS) 100 according to an embodiment of the present invention. An input voltage Vin is coupled to a first terminal 105 of switch 100 which is coupled to the input of switch module 110 . Terminal 115 is the output terminal of switch 100 . Input line 101 couples binary signal S to switch 100 and controls the operation of switch 100 . When S=a binary “1” or high, then switch 100 is ON and Vin is connected to Vout. When S=“0” or low, then switch 100 is OFF and Vin is disconnected from Vout.
[0014] Switch module 110 is controlled by switch controller 120 , which receives binary signal S. Switch controller 110 includes voltage level controller 125 , level shifters 130 and 135 and gate voltage controller 140 . Input line 101 couples signal S to voltage level controller 120 , which generates control signals C and Cb. Cb is the logical complement of C. Control signals C and Cb are coupled to respective level shifters 130 and 135 , which generate respective control signals U and Ub. Ub is the logical complement of U. Input voltage Vin and control signals C, Cb, U and Ub are coupled to gate voltage controller 140 , which generates the gate control voltages needed to control the operation of switch module 110 by way of multiple control lines 141 . When a gate voltage follows the input voltage Vin, the voltage applied to the gate is equal to the input voltage and a small offset voltage Voffset, in which case the gate control voltage=Vin+Voffset. Switch 100 receives a first supply voltage Vdd and a second supply voltage=2×Vdd, which are not shown in FIG. 1 .
[0015] Switch 100 can be implemented in a low voltage CMOS process forming MOSFET transistors with a breakdown voltage of, for example 3.3 volts, operating with a typical first supply voltage Vdd=3.0 volts and a typical second supply voltage 2×Vdd, but with the capability of switching an input voltage Vin of approximately 6 volts (or approximately 2×Vdd) without exceeding the breakdown voltage of any of the MOSFET transistors in switch 100 .
[0016] Switch 100 is a floating switch in that when switch 100 is in the off state, the input voltage Vin and the output voltage Vout can be at any voltage potential.
[0017] FIG. 2 shows an exemplary table of relative voltage levels for control lines C, Cb, U and Ub within switch controller 120 for the switch of FIG. 1 . Switch controller 120 converts binary signal S to control signals with three voltage levels: ground and supply voltages Vdd and 2×Vdd. Switch 100 is in the OFF state, if C=Gnd, Cb=Vdd, U=Vdd and Ub=2×Vdd. Switch 100 is in the ON state, if C=Vdd, Cb=Gnd, U=2×Vdd and Ub=Vdd.
[0018] FIG. 3 shows a circuit diagram of an exemplary switch module 310 for the high voltage switch of FIG. 1 . Switch module 310 includes three parallel circuit paths ( 301 , 302 and 303 ), where each path is made of three series connected MOSFET transistors. The bulk terminal of each transistor is usually connected to the source terminal of the corresponding transistor. The breakdown voltage limit across any terminals to the bulk terminal of each individual transistor is not a concern throughout the discussion below. Circuit path 301 includes transistors M 1 , M 2 and M 3 of a first polarity controlled by respective gate control voltages: Vdd, V 1 M and Vdd and with node voltages V 1 a and V 1 b between the transistors. Circuit path 302 includes transistors M 4 , M 5 and M 6 of a first polarity controlled by respective gate control voltages: V 2 L, V 2 M and V 2 L and with node voltages V 2 a and V 2 b between the transistors. The voltage levels for V 2 L, V 2 M and V 2 L are not limited to the three voltage levels previously mentioned: Gnd, Vdd and 2×Vdd. These voltages also depend on the input voltage Vin in some modes of operation, as will be described with respect to FIG. 5 . Circuit path 303 includes transistors M 7 , M 8 and M 9 of a second polarity controlled by respective gate control voltages: Vdd, V 3 M and Vdd and with node voltages V 3 a and V 3 b between the transistors.
[0019] The first (M 1 , M 4 , M 7 ) and the third (M 3 , M 6 , M 9 ) transistors in each of the three circuit paths are voltage range limiting transistors, which limit the voltage across the middle transistors (M 2 , M 5 , M 8 ) and prevent the voltages across all of the transistors from exceeding their breakdown voltages.
[0020] FIG. 4 shows the on/off state of each of the transistors in the three circuit paths as switched on or off by gate voltage controller 140 in accordance with the input voltage range. When switch 100 is in the ON state, the ON state resistance of the switch is assumed to be significantly lower than the load resistance connected to the output of switch 100 such that the output voltage Vout at terminal 115 can be considered to be equal to the input voltage Vin at terminal 105 .
[0021] When switch 100 is in the ON state, and the input voltage is in the low range of: 0<Vin<Vdd−Vt, where Vt is the typical threshold voltage of a MOSFET transistor, then the first circuit path 301 transistors M 1 , M 2 and M 3 are turned on by gate voltage controller 140 .
[0022] When switch 100 is in the ON state, and the input voltage is in the middle range of: Vdd−Vt<Vin<Vdd+Vt, then the second circuit path transistors M 4 , M 5 and M 6 are turned on by gate voltage controller 140 . Since transistors M 4 , M 5 and M 6 in the second circuit path 302 have the same polarity as transistors M 1 , M 2 and M 3 in the first circuit path 301 , transistors M 4 , M 5 and M 6 are also turned on by gate voltage controller 140 , when Vin is in the middle voltage range.
[0023] When switch 100 is in the ON state, and the input voltage is in the high range of: Vdd+Vt<Vin<2×Vdd, then only the third circuit path 303 transistors M 7 , M 8 and M 9 are turned on by gate voltage controller 140 .
[0024] When switch 100 is in the OFF state, and the input voltage is in the low range of: 0<Vin<Vdd−Vt, then only the first circuit path 301 transistors M 1 and M 3 are turned on by gate voltage controller 140 .
[0025] When switch 100 is in the OFF state, and the input voltage is in the middle range of: Vdd−Vt<Vin<Vdd+Vt, then only the first circuit path transistors M 1 and M 3 are turned on by gate voltage controller 140 .
[0026] When switch 100 is in the OFF state, and the input voltage is in the high range of: Vdd+Vt<Vin<2×Vdd, then only the third circuit path 303 transistors M 7 and M 9 are turned on by gate voltage controller 140 . Since the middle transistors (M 2 , M 5 and M 8 ) of all three paths ( 301 , 302 and 303 ) are turned off when switch 100 is in the OFF state, there will be no current flow between the input voltage Vin at terminal 105 and the output voltage Vout at terminal 115 .
[0027] The turning on and off of the various circuit paths overlap for different input voltage ranges to some extent since the transistors are not completely turned on or off as the input voltage Vin varies from one range to another range and there may still be some conduction of current within the transistors, except for transistors M 2 , M 5 and M 8 in the OFF state. Switch 100 uses three circuit paths operating at three different (but with some overlap) voltage ranges in order to provide a relatively undistorted connection in the on state between Vin and Vout across the input voltage range of Vin.
[0028] FIG. 3 shows that the gate voltages connected to transistors M 1 and M 3 in the first circuit path 301 and transistors M 7 and M 9 in the third circuit path 303 in all states of operation are set to the first supply voltage Vdd. The table in FIG. 5 shows the gate voltages applied to the other transistors (M 2 , M 4 , M 5 , M 6 and M 8 ) in switch module 310 as a function of the state of switch 100 and the range of the input voltage Vin. For transistors M 4 , M 5 and M 6 in the second circuit path 302 , when the input voltage Vin is in the middle or high range, the gate voltages of these transistors follow the input voltage, plus an offset voltage Voffset. The offset voltage Voffset is slightly greater than Vt such that the gate voltages of transistors M 4 , M 5 and M 6 are always higher than the input voltage Vin by Vt to keep transistors M 4 , M 5 and M 6 on. The gate voltages of the other transistors in the table in FIG. 5 , are either set to Vdd or 0V, when switch 100 is in the OFF state.
[0029] When switch 100 is in the OFF state and no current flow is allowed in all three paths, then the gate voltages for M 2 and M 5 are at zero volts, and the gate voltage for transistor M 8 is set to Vdd. The gate voltages for transistors M 1 , M 3 , M 4 , M 6 , M 7 and M 9 are set to Vdd for limiting the source voltages and the drain voltages of transistors M 2 , M 5 and M 8 within one Vdd. The source voltages and the drain voltages for transistors M 1 , M 3 , M 4 , M 6 , M 7 and M 9 are also limited to within one Vdd for the input voltage at terminal 105 and the output voltage at terminal 115 varying within the voltage range between 0V and 2×Vdd.
[0030] FIG. 6 shows a table of node voltages for the switch module of FIG. 3 . Based on the node voltages for different input and output voltage ranges in the ON and OFF states, it can be observed that the voltages across the different terminals of all the transistors are less than the breakdown voltage of any of the transistors in switch 100 .
[0031] FIG. 7 shows a circuit diagram for an alternate embodiment of the high voltage switch 700 of the present invention. For purposes of simplifying the diagram, electronic circuits equivalent to the level shifters 130 and 135 of FIG. 1 are not shown in FIG. 7 . An equivalent to the gate voltage controller 140 of FIG. 1 is part of the circuit of FIG. 7 . Control signals C, Cb, U and Ub, discussed previously, are shown connected to switch 700 to the gates of various transistors of switch 700 . The third path 303 in FIG. 3 is equivalent to transistors M 9 , M 10 and M 11 in FIG. 7 . Since the first path 301 and the second path 302 in FIG. 3 have transistors with the same polarity, some transistors in the two paths can be combined together if proper gate voltage controls are applied. Transistors M 1 and M 4 in FIG. 3 are combined together as transistor M 5 in FIG. 7 . Similarly, transistors M 3 and M 6 in FIG. 3 are combined together as transistor M 8 in FIG. 7 . Transistor M 19 in FIG. 7 is equivalent to transistor M 2 in FIG. 3 . Due to the specific gate voltage controller design shown in FIG. 7 , transistors M 5 in FIG. 3 is replaced by transistors M 6 and M 7 in FIG. 7 . Transistors M 15 and M 16 connected in between M 6 and M 7 at node Z are used to ensure that no current flows through transistors M 6 and M 7 during the OFF state.
[0032] When switch 700 is turned ON by input signal S=“1” (not shown in FIG. 7 ), then transistors M 5 , M 19 and M 8 form a circuit path between Vin and Vout that is turned on when the input voltage Vin is in the low range: 0<Vin<(Vdd−Vsg 4 ) where Vsg 4 is the source-to-gate voltage of transistor M 4 . For the input voltage range Vin<˜(Vdd−Vsg 4 ), PMOS transistor M 4 is in the triode region of operation such that Vx is equal to Vdd. Node Y is floating between Vdd and 0V, since M 14 (the source voltage of M 14 is equal to Vx and hence, equal to Vdd, since transistor M 13 is on) and M 18 are off. The gate voltages of this first circuit path (transistors M 5 , M 19 and M 18 ) are all at Vdd. This circuit path is similar to the first circuit path 301 as discussed with regard to FIG. 3 .
[0033] When switch 700 is turned ON and the input voltage Vin is in the middle range, ˜Vdd−Vsg 4 <Vin<(2×Vdd)−Vsg 4 , then transistors M 5 , M 6 , M 7 and M 8 form a circuit path between Vin and Vout, similar to the second circuit path 302 discussed with regard to FIG. 3 . Transistor M 1 in FIG. 7 is biased as a current source set by a proper gate bias voltage Vswb. Transistors M 1 , M 2 and M 4 form a source follower, such that the voltage at node X will follow Vin with an offset voltage such that Vx=Vin+Vsg 4 , where Vx=voltage at node X. Node Y will follow node X such that Vx=Vy, since transistors M 12 , M 13 and M 14 are conducting for this input voltage range. Therefore, transistors M 5 , M 6 , M 7 and M 8 are turned on with their gate to source voltages equal to Vsg 4 . The on resistance for this Vin range is smaller if a small (W/L) is used for transistor M 4 , as this will maximize Vsg 4 . In the upper reaches of this Vin input voltage range, the branch M 9 , M 10 and M 11 is also turned on.
[0034] When switch 700 is turned ON and the input voltage Vin is in the high range 2×Vdd>Vin>|Vtp|+Vdd, (where Vtp is the typical threshold voltage for a PMOS transistor) then a circuit path from Vin to Vout is connected through transistors M 9 , M 10 and M 11 . This circuit path is similar to the third circuit path 303 as discussed with regard to FIG. 3 .
[0035] When switch 700 is turned OFF and the input voltage Vin is in the low range: 0<Vin<Vdd−Vtn, the gate voltages of transistors M 5 and M 8 are equal to Vdd (transistor M 3 is on) and hence, transistors M 5 and M 8 are turned on. No conduction path is established between transistors M 5 and M 8 since M 19 is off and nodes Y and Z are at 0V to keep transistors M 6 and M 7 off.
[0036] When switch 700 is turned OFF and the input voltage Vin is in the high range: Vdd+|Vtp|<Vin<2×Vdd, (where Vtp is the typical threshold voltage for a PMOS transistor), transistors M 9 and M 11 are on, but transistor M 10 is turned off. Transistors M 5 and M 8 are also turned on in the middle input voltage range: Vdd−Vtn<Vin<2×Vdd. Transistors M 5 , M 8 , M 9 and M 11 during their periods of operation limit the voltage swings across the inner transistors M 6 , M 7 , M 10 and M 19 , which are always off when switch 700 is off.
[0037] When switch 700 is in the OFF state, the gate voltages of M 9 and M 11 are at Vdd, forcing the source and drain voltages of M 10 to be between Vdd+|Vtp 9 , 11 | and 2×Vdd, even though Vin and/or Vout may vary rail-to-rail between 0V and 2×Vdd. Hence, M 9 -M 11 will not be under stress when switch 700 in the off state.
[0038] In all of these various operational configurations, the voltages across the different terminals of all the transistors are less than the breakdown voltage, whether switch 700 is on or off.
[0039] Although the preceding description describes various embodiments of the system, the invention is not limited to such embodiments, but rather covers all modifications, alternatives, and equivalents that fall within the spirit and scope of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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A high voltage analog switch operable by a binary signal is implemented in a low voltage semiconductor process. The switch has three parallel circuit paths, with each path comprising at least three series connected transistors. Control signals are selectively applied to the control terminals of the transistors to control the switch and selectively turn on or turn off each of the three circuit paths depending on the input voltage range, so that the breakdown voltage of all of the transistors is never exceeded in any mode of operation.
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BACKGROUND OF THE INVENTION
The thread tension device on a sewing machine is intended to apply a prescribed amount of "drag" on the sewing thread to enable the sewing machine to properly set a stitch. Depending upon the type and thickness of the material being sewn, as well as the type and thickness of the thread, the drag, or tension setting, is varied such that an optimum stitch may be obtained. Ordinarily, thread tension devices use a spring for applying a compressive force to a set of tension discs between which the thread is passed. A screw arrangement is used to vary the compression on the spring thereby varying the tension on the thread. If the thread passing between the discs is uniform, this arrangement will supply a constant uniform tension to the thread. However, in actuality, the thread is not uniform and there are variations in the thickness thereof. This causes the tension discs to separate increasing the compression on the spring which, in turn, exerts a greater compressive force on the thread. This varying tension may result in improperly set stitches and even possible breakage of the thread itself.
SUMMARY OF THE INVENTION
The object of this invention is to provide a tension device for a sewing machine capable of exerting uniform tension on a thread regardless of variations in the thickness thereof. This object is achieved in a tension device having a set of thread tensioning discs, between which the thread passes by applying a uniform compressive force on the tension discs independent of the spacing therebetween by means of an electro-magnetic actuator which develops a uniform force in response to any given level of electrical current input.
DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in mind as will hereinafter appear, the invention will be described with reference to the attached drawings in which:
FIG. 1 is a front elevational view of the head of a sewing machine, partly in section, showing the invention incorporated therein;
FIG. 2 is an exploded perspective view of the tension device of this invention;
FIG. 3 is a lengthwise cross-sectional view of the linear actuator of this invention;
FIG. 4 is a cross-sectional view of the linear actuator taken along the line of 4--4 of FIG. 3;
FIG. 5 is a lengthwise cross-sectional view of a linear actuator in a second embodiment of this invention,
FIG. 6 is a cross-sectional view of the linear actuator taken along the line 6--6 of FIG. 5; and
FIG. 7 is a perspective view of the first embodiment of this invention diagrammatically showing the electrical circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 a sewing machine is shown as having a bed 10 and a sewing head 12. A needle bar 14 is carried within the sewing head 12 and is arranged for reciprocatory motion. A sewing needle 16 is removably attached to the exposed end of the needle bar 14 by means of a screw clamp 18. Also carried in the sewing head 12 is a downwardly biased presser bar 20 having a presser foot 22 removably attached thereto by a screw clamp 24. The presser foot 22, under the influence of the downward bias on the presser bar 20, urges the material being sewn into engagement with a feed mechanism characterized by a feed dog 26 located in the bed 10 of the sewing machine.
In order for the sewing machine to properly make a stitch, a certain amount of drag, or tension, must be applied to a sewing thread T. To this end, the tension device 30 of this invention may be found within the sewing head 12. The tension device 30 as shown and described herein has two thread paths such that it may be used to tension two sewing threads simultaneously. However, a single thread may also be used effectively with the device for which the following discussion will pertain. The tension device 30 as shown in FIG. 2 includes a frame 32 having a hollow tube 34, with a longitudinal split 36 therein, depending from the frame 32. A first thread guiding plate 38 is formed with a hole 40 therein for slidably engaging the tube 34. A set of tension discs 42, 44, and 46 are provided for engaging the sewing thread T. The tension discs 42 and 46 are identical and are each respectively formed with a circular aperture 48 and 50 therethrough for rotatably engaging the tube 34. The tension disc 44, which is located between the tension discs 42 and 46, is substantially larger than the discs 42 and 46 such that the tension disc 44 may act as a guide for thread entering between the tension disc 44 and either of the tension discs 42 or 46. An aperture 52 is formed in the tension disc 44 for slidably engaging the tube 34. Tabs 54 extend from the tension disc 44 into the aperture 52 and engage the slot 36 in the tube 34 preventing the tension disc 44 from rotating. A second thread guiding plate 56 is provided for guiding the thread from the tension discs 42, 44 and 46 to other thread manipulating instrumentalities with which the present invention is not concerned, such as a check spring, thread takeup (none of which are shown). Clearance holes 58, 60 and 62 are formed respectively in the frame 32, the first thread guiding plate 38 and the second thread guiding plate 56 through which a screw 64 passes for mounting the tension device 30 in the sewing head 12.
In order to apply a compressive force to the tension discs 42, 44, 46, a pin 66 is provided for passing through the tube 34. The pin 66 is formed with a first shoulder 68 at one end thereof for engaging a retaining disc 70 which, in turn, bears against the tension discs 42, 44 and 46. The opposite end of the pin 66 extends outside the frame 32 and is formed with a second shoulder 72 which is engaged by a bell crank 74 having a first arm 76 bifurcated for embracing the pin 66 and abutting the second shoulder 72. The bell crank 74 is pivotally mounted on a pin 78 and includes a second arm 80 which is pivotally engaged by a linear actuator 82.
The linear actuator 82, as shown in FIGS. 3 and 4, includes a base 84, a cylindrical frame 86 extending from the base 84, and a guide stud 88 also extending from the base 84, coaxial with the frame 86. The base 84, the frame 86 and the stud 88 are all made of a magnetic material. An electrical coil 90, wrapped around a non-magnetic spool 92, is mounted to the inner periphery of the frame 86. The remaining space between the spool 92 and the stud 88 is occupied by a cylindrical armature 94 having a central bore 96 for slidably engaging the stud 88. In accordance with the teachings in U.S. Pat. No. 4,065,739 of Jaffe, et al, a flexible magnet 98, having previously been magnetized, is wrapped around the outside of the armature 94 and is secured thereto as by an adhesive or the like. In order for the electro-magnetic actuator 82 to output a uniform force in response to any given level of electrical current input to the electrical coil 90, the over all length of the flexible magnet 98, when installed on the armature 94, should be less than the length of the electrical coil 90; the difference in the lengths of the parts 90 and 94 establishing the range of movement of the armature 94 in response to energization of the coil 90 over which a constant force will be exerted thereon. The magnet 98 should be arranged adjacent to the electrical coil in all positions within the range of movement; and both the electrical coil 90 and the armature 94 should be electrically and magnetically uniform throughout their entire lengths. The exposed end 99 of the armature 94 is bifurcated for embracing the second arm 80 of the bell crank 74. Clearance holes 100 are formed through both the bifurcated end 99 of the armature 94 and the bell crank 74 second arm 80 through which a pivot pin 102 is passed.
FIG. 7 shows a sample electrical circuit for energizing the linear actuator 82. Electrical power is provided by a regulated voltage supply (not shown) and travels along a wire 110 to a variable current control 112, such as a potentiometer, mounted on the sewing head 12, accessible to the operator. The control 112 has indicia 114 thereon relating to the amount of tension being applied to the thread. A wire 116 connects the current control 112 to a tension release switch 118 including a switch opening element 119 preferably located in the path of the presser bar or in the path of an element carried on the presser bar which opens the circuit thereby releasing the tension whenever the presser bar 20 is lifted. A wire 120 connects the switch 118 to the linear actuator 82. A wire 122 then connects the actuator 82 back to the voltage supply.
In operation, the regulated voltage supply is activated and the operator sets the desired tension by operating the variable current control 112. After the operator threads the sewing machine, that is, passes thread T from a thread supply over the first thread guide 38, between the tension discs 44 and 42 or 46, around the second thread guide 56 and onto the sewing needle 16, when the operator lowers the presser bar 20 causing the presser foot 22 to engage the material that is to be sewn, the switch 118 closes allowing the linear actuator 82 to be energized. Depending upon the setting of the current control 112, the actuator 82 exerts a prescribed downward force on the bell crank 74 second arm 80, causing the bell crank 74 to pivot about the pin 78. The pivoting of the bell crank 74 causes the first arm 76 thereof to pull against the second shoulder 72 of the pin 66, forcing the retaining disc 70, abutting the first shoulder 68 of the pin 66, to bear against the tension discs 42, 44 and 46, thereby applying tension to the thread therebetween. If the thickness of the thread T changes, the spacing between the applicable discs 42 and 44 or 44 and 46 changes accordingly while the linear actuator 82 exerts the same amount of force thereon. Depending upon the ratio of the length of the first arm 76 to the second arm 80 of the bell crank 74, the force exerted by the actuator 82 may be multiplied, thereby minimizing the size of the actuator 82 which would be required.
In FIGS. 5 and 6, there is shown an alternate construction of the tension device 30 wherein a linear actuator 130 acts directly upon a set of tension discs 132 and 134. The tension disc 132 is mounted to the end of the actuator 130 armature 136, while a tension disc 134 is slidably mounted thereon. The actuator 130, which is basically identical to the actuator 82, includes an end cap 138 having a thread bearing surface 140 formed thereon. The thread bearing surface 140 on the end cap 138 is shaped complimentary to the tension disc 134 and, in operation, the action of the armature 136 forces the tension disc 132 to move the disc 134 into engagement with the surface 140.
In FIG. 7 the electrical circuit includes two different control elements: the switch 118 adapted to effect control of the tension in response to a particular operation of an instrumentality of the sewing machine; and a manual control 112. It will appreciated that other control arrangements responsive, for instance, to data stored in an electronic memory could also be used with the device of this invention to provide for automatic tension control.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit and scope of the invention are intended to be included within the appended claims.
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A tension device for sewing machines is disclosed having thread tensioning discs and a linear actuator for applying a compressive force between the discs. The invention is characterized in that for any given tension setting of the device, the applied compressive force, or tension, remains constant regardless of any variations in the spacing of the discs due to variations in the thread thickness, up to the range of travel of the linear actuator.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention is directed to a technique for performing functional verification of a device, and in particular is directed to a self-verification technique for performing on-chip or internal device clock generation verification by the chip/device which contains the clock generation circuitry.
[0003] 2. Description of Related Art
[0004] Boundary scan is a methodology allowing controllability and observability of the boundary pins of a JTAG compatible device via software control. This capability enables in-circuit testing without the need of bed-of-nail in-circuit test equipment. Certain boundary scan techniques are known, such as those described in the IEEE 1149.1 Specification known as IEEE Standard Test Access Port and Boundary Scan Architecture (which is hereby incorporated by reference as background material). Included in such a boundary scan methodology are certain data and control signals including scan-in and scan-out data signals and a scan clock control signal.
[0005] Many types of integrated circuit devices such as microprocessors use phase-locked loop (PLL) circuitry to multiply a reference clock and achieve a high frequency clock for use by the microprocessor's transistor logic. In new transistor technologies, PLL yield and reliability may often be suspect. Verifying the output of the PLL (i.e. the internally generated clock signal) typically requires a probe and oscilloscope, or complex timebase logic that requires a separate timebase clock. However, once the microprocessor or other device (having the internal PLL circuitry) is placed in a system, external probes may be difficult to connect. In addition, because of pin restrictions, the PLL output may not be brought out to a pin of the integrated circuit device (the integrated circuit device also being known as a ‘chip’). In a bring-up system, the timebase clock may not exist and the timebase logic may not be functional.
[0006] It would thus be desirable to provide an on-chip ability to verify PLL functionality with the aid of existing on-chip circuitry and associated clock signals such as a JTAG scan clock control signal.
SUMMARY OF THE INVENTION
[0007] The present invention provides a system and method for performing functional verification of a device, and in particular a technique for performing phase-locked loop (PLL) functional verification by the device which contains the PLL circuitry. A relatively slow-speed external clock is provided to the device, and is used to generate control signals to a counter. PLL circuitry within the device generates a relatively high-speed master clock signal for use by the device. This master clock signal is coupled to a clock input of the counter, the counter having various control inputs that are used to selectively count clock pulses of the master clock. As the frequency of the external clock signal is known, and the master clock signal is generated from known PLL circuitry, it is possible to analyze the count value from the counter to determine whether the PLL circuitry used to generate the master clock is operating properly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0009] FIG. 1 depicts a circuit for generating a clock edge detect control signal.
[0010] FIG. 2 depicts a circuit for generating a measure request edge detect control signal.
[0011] FIG. 3 depicts a circuit for generating a count control signal.
[0012] FIG. 4 depicts a timing diagram of various control signals used to verify functionality of a phase-locked loop (PLL) circuit.
[0013] FIG. 5 depicts a counter being controlled to assist in verifying functionality of a phase-locked loop (PLL) circuit.
[0014] FIG. 6 depicts a phase-locked loop (PLL) circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Because boundary scan techniques such as JTAG boundary scan are well known to those of ordinary skill in the art, the details of boundary scan will not be described herein in order to maintain focus on the techniques of the present invention. Suffice it to say that the JTAG boundary scan definition includes a boundary scan clock sometimes called TCK. The present invention makes use of such boundary scan clock in performing a phase-locked loop (PLL) on-chip verification.
[0016] A phase-locked loop circuit typically uses a reference clock as an input, and through the use of circuitry used to couple the output of the PLL to the input in a feedback path, it is possible to create an output PLL clock signal that is of a higher frequency than the input reference clock frequency. Such a technique is shown at 600 in FIG. 6 . There, a reference clock 602 , such as from a crystal oscillator, is provided to an input of a phase detector 604 . The output of the phase detector is coupled to the input of charge pump 606 . The output of charge pump 606 is coupled to the input of low pass filter 608 . The output of low pass filter 608 is coupled to the input of voltage controlled oscillator (VCO) 610 , and the output of the VCO 610 is the PLL output clock signal 612 . The output of VCO 610 is also used in a feed-back loop to provide a clock-multiplication effect of the PLL. Specifically, the output of VCO 610 is coupled to the input of a divide-by-N circuit 614 . The output of divide-by-N circuit 614 is coupled to another input 616 of phase detector 604 , thus completing the PLL control feed-back path. This is a representative example of a phase-locked loop clock generation circuitry for which the present invention provides on-chip verification.
[0017] The generation of various control signals used by the present design will now be described. Referring first to FIG. 1 , there is shown at 100 a technique for generating a TCK_EDGE control signal 102 from an externally provided JTAG CLOCK signal 104 using an edge detect circuit 106 . This JTAG CLOCK signal is also known as a JTAG scan clock.
[0018] Referring next to FIG. 2 , there is shown at 200 a technique for generating a MEASURE_REQUEST_EDGE control signal 202 from a MEASURE REQUEST control signal 204 using an edge detect circuit 206 . This MEASURE REQUEST control signal 204 is generated internal to the integrated circuit device, for example by an embedded controller or processor, and signals a desire to measure the PLL output clock signal.
[0019] Referring now to FIG. 3 , a circuit 300 is shown for generating various control signals, including the CLEAR_COUNTER and KEEP_COUNTING control signals which are used to verify PLL functionality as will be further described below. This circuitry 300 makes use of the previously described control signals TCK_EDGE and MEASURE_REQUEST_EDGE, shown in FIG. 3 at 102 and 202 , respectively. An S-R flip flop 302 has at its S-input the MEASURE_REQUEST_EDGE control signal 202 , and has at its R-input a DONE control signal 204 . The Q-output from S-R flip flop 302 is coupled to AND gate 304 . Coupled to another input of AND gate 304 is the TCK_EDGE control signal 102 . The output of AND gate 304 is coupled to the S-input of S-R flip flop 306 . The DONE control signal 204 is also coupled to the R-input of S-R flip flop 306 . The Q-output of S-R flip flop 306 is coupled to the D-input of D flip flop 308 . The Q-output of D flip flop 308 is coupled to the D-input of D flip flop 310 . The Q-output of D flip flop 308 is also coupled to a non-inverted input of AND gate 312 . The Q-output of D flip flop 310 is coupled to an inverted input of AND gate 312 , and the output of this AND gate 312 is the generated control signal CLEAR_COUNTER 322 (to be further described below). The Q-output of D flip flop 310 is also coupled to an input of AND gate 314 . Coupled to another input of AND gate 314 is the TCK_EDGE control signal 102 . The output of AND gate 314 is coupled to the S-input of S-R flip flop 316 . Coupled to the R-input of S-R flip flop 316 is the DONE control signal 204 . The Q-output of S-R flip flop 316 is the generated control signal KEEP_COUNTING 320 (to be further described below). The Q-output of S-R flip flop 316 is also coupled to AND gate 318 . Control signal TCK_EDGE 102 is coupled to another input of AND gate 318 , and the output of AND gate 318 is the DONE control signal 204 previously described as being used as the signal coupled to the R-input of various S-R flip flops such as 302 , 306 and 316 . Certain operational aspects of this circuit 300 will now be described with reference to the timing diagram 400 shown in FIG. 4 .
[0020] Referring now to timing diagram 400 of FIG. 4 , there is shown the timing relationship of four control signals JTAG CLOCK 402 , TCK_EDGE 404 , MEASURE_REQUEST_EDGE 406 , and KEEP_COUNTING 408 . These correspond to the respective signals shown at JTAG CLOCK 104 of FIG. 1 , TCK_EDGE 102 of FIG. 1 , MEASURE_REQUEST_EDGE 202 of FIG. 2 , and KEEP_COUNTING 320 of FIG. 3 . As can be seen, the TCK_EDGE control signal 404 provides a pulse 410 responsive to the JTAG CLOCK signal 402 transitioning from a logic ‘0’ to a logic ‘1’ at 412 , in effect providing an edge detect control signal based upon JTAG CLOCK signal 402 having a ‘0’to ‘1’ edge transition (of course, an alternate embodiment could reverse all logic control signals and use a logic ‘0’ as the active logic control state). The KEEP_COUNTING control signal 408 is shown to go from a logic ‘0’ to a logic ‘1’ at 416 , and to go from a logic ‘1’ to a logic ‘0’ at 418 . The transition of KEEP_COUNTING from ‘0’ to ‘1’ is responsive to a second successive TCK_EDGE pulse, and is the result of the TCK_EDGE control signal being coupled to both S-R flip flop 306 by way of AND gate 304 and S-R flip flop 316 by way of AND gate 314 ( FIG. 3 ). Similarly, the transition of KEEP_COUNTING from ‘1’ to ‘0’ is responsive to the TCK_EDGE control signal 102 being coupled to S-R flip flop 318 ( FIG. 3 ), which results in the DONE signal 204 going active which resets all the S-R flip flops 302 , 306 and 316 and thus disables the KEEP_COUNTING control signal 320 . The use of the KEEP_COUNTING control signal as a part of PLL on-chip verification will now be described with respect to FIG. 5 .
[0021] Referring now to FIG. 5 , there is shown at 500 a circuit for generating a multi-bit DATAOUT signal at 508 which as will be described below provides verification of the output PLL clock signal of a PLL circuit such as PLL output clock signal 612 shown in FIG. 6 . A KEEP_COUNTING signal 320 , as previously described with respect to FIGS. 3 and 4 , is coupled to the INCREMENT input of counter 502 . A CLEAR_COUNTER signal 322 , as previously described with respect to FIG. 3 , is coupled to the RESET input of counter 502 . The PLL output clock signal, such as signal 612 of FIG. 6 , is used as a general purpose system clock signal for the integrated circuit device, and is coupled to the clock input (indicated by an upside-down V) of each individual circuit such as is shown at 510 of FIG. 5 (this system clock signal is also coupled to the upside-down V clock inputs of the various circuits shown in FIG. 3 ). The counter 502 counts clock pulses appearing on the clock input signal 510 when the INCREMENT control signal of the counter is active—in this particular embodiment when the KEEP_COUNTING control signal 320 is active. The count of the clock pulses is provided at the output of the counter 502 , as DATAOUT signal 508 . Thus, the DATAOUT signal 508 provides a count of the number of PLL output clock signals that occur during the time that the KEEP_COUNTING signal is active, for example the time during the positive going pulse 416 and the negative going pulse 418 shown in FIG. 4 . This DATAOUT signal 508 can then be read by circuitry within the device itself, such as an embedded controller or microprocessor, to verify proper PLL operation by examining the DATAOUT signal 508 . The frequency of this global clock signal may be calculated since the period of the externally provided JTAG clock is known, and thus the expected frequency of the PLL generated clock can be determined based upon this known external clock frequency.
[0022] In an alternate embodiment, scan ports of the counter 502 are used to pre-load the counter with a known value. If the DATAOUT of the counter maintains its preloaded value after the MEASURE_REQUEST control signal has been issued, this is an indicator that the PLL circuitry may be completely non-functional.
[0023] Thus, by use of an externally provided clock signal, in this instance a JTAG CLOCK signal or scan clock, in combination with on-chip PLL verification circuitry, it is possible for a device to itself determine whether its internally generated clock signal is operating properly.
[0024] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
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A system and method for performing functional verification of a device, and in particular a technique for performing phase-locked loop (PLL) functional verification by the device which contains the PLL circuitry. A relatively slow-speed external clock is provided to the device, and is used to generate control signals to a counter. PLL circuitry within the device generates a relatively high-speed master clock signal for use by the device. This master clock signal is coupled to a clock input of the counter, the counter having various control inputs that are used to selectively count clock pulses of the master clock. As the frequency of the external clock signal is known, and the master clock signal is generated from known PLL circuitry, it is possible to analyze the count value from the counter to determine whether the PLL circuitry used to generate the master clock is operating properly.
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RELATED APPLICATIONS
This file is a continuation-in-part application of prior patent application for a "Multi-Stage Infectious Waste Treatment System", Ser. No. 214,597, filed Mar. 18, 1994 now U.S. Pat. No. 5,425,925, which is a continuation-in-part of an application for a "Method for Sterilizing and Disposing of Infectious Waste," Ser. No. 690,116, filed Apr. 23, 1991 now abandoned, which was a continuation-in-part of application Ser. No. 511,275, filed Apr. 19, 1990, now U.S. Pat. No. 5,089,228.
FIELD OF THE INVENTION
The present invention relates generally to treatment of infectious waste. More particularly, the present invention relates to a system which mechanically fragments and decontaminates infectious waste. The present invention is particularly, though not exclusively, useful for treating an infectious waste stream which includes a variety of types of waste.
BACKGROUND OF THE INVENTION
The disposal of infectious waste from hospitals and other medical establishments is a major problem. Indeed, the importance of proper and effective infectious waste disposal has become of greater concern in recent years, due to an increased awareness of health problems such as the AIDS epidemic. In part because of the AIDS epidemic, definitions of what constitutes "infectious waste" are being broadened. Consequently, the volume of infectious waste which must be disposed of is increasing. Accordingly, the need for a system or apparatus which will accomplish the safe, efficacious, and cost effective treatment of significant volumes of infectious waste for disposal is growing.
One method for decontaminating infectious waste involves incineration, wherein the waste is burned and the decontaminated ashes are properly disposed. An alternative treatment method is to disinfect the waste in a steam autoclave prior to waste disposal. While effective for their intended purposes, both incinerators and autoclaves present ancillary problems. Incinerators, for example, are difficult and costly to construct and are relatively expensive to maintain in an environmentally safe manner. Autoclaves too, present additional problems, such as odor, cost and operational complexity. Additionally, waste which has been disinfected by autoclaving typically requires further treatment procedures, such as incineration or shredding and granulation, prior to final disposition of the waste in such places as landfills.
With the above discussion in mind, alternative infectious waste treatment systems have been proposed to disinfect the waste in preparation for disposal. According to these proposals, a solid infectious waste is contacted with a disinfectant solution containing a chlorine compound to decontaminate the waste. The decontaminated waste may then be disposed in ordinary landfills.
Unfortunately, decontamination of waste using chlorine compounds presents certain technical complications. First, liquid disinfectant loses its disinfectant potency during prolonged storage. Thus, there is a need to use liquid disinfectant that is relatively "fresh" in order to achieve an acceptable degree of waste decontamination. Second, it is relatively difficult to ensure that an appropriate concentration of the disinfectant has contacted the waste during the treatment process. It is also important, however, to avoid applying too high a concentration of chlorine compound to the waste, in order to avoid undesirable results, such as corrosive effects and the release of toxic gases. Significant health risks are known to result from the discharge of chlorine to the environment.
The most commonly used disinfectant is sodium hypochlorite, typically as a one percent solution. The strength of the solution is dictated by the necessity of achieving a desired rate of bacteria kill in a given apparatus, resulting in a given rate of use of the disinfectant when operating at a given rate of throughput of waste. The use of a one percent solution results in the discharge of a significant amount of chlorine into the environment from the typical apparatus, either into the sewer or absorbed into the processed waste.
Because of its higher reactivity, chlorine dioxide is far more effective than sodium hypochlorite for the treatment of infectious waste. Chlorine dioxide also typically exists as a gas in solution, greatly enhancing the penetration of the disinfectant into the waste material. Chlorine dioxide can, if applied to properly granulated waste, achieve the necessary kill rate at a concentration of only about 50 ppm, or only about 0.005 percent, or 5 one-thousandths of the necessary concentration of sodium hypochlorite. Finally, the chlorine dioxide is far less environmentally persistent, rapidly disassociating into sodium chloride, water, and citric acid. When taking into account the rate of use of sodium hypochlorite in a typical process, and the required rate of use of properly applied chlorine dioxide to achieve the same kill rate, the sodium hypochlorite process results in the discharge to the environment of approximately ten thousand times as much of the treatment chemical. This means that the chlorine dioxide process results in the discharge to the environment of an amount of chlorine which is minuscule, compared to the amount of chlorine discharged by the sodium hypochlorite process.
Unfortunately, chlorine dioxide is very corrosive, highly unstable, and even explosive. It can not simply be substituted for sodium hypochlorite in a process. It must be used in an apparatus designed to properly generate and mix the chemical, and designed to properly granulate and handle the waste material to allow the use of a very low concentration of the chemical. Further, it is impractical to store chlorine dioxide, because it is an oxidizer and exposure to oxidizable impurities would consume a portion of the chlorine dioxide. Effective exclusion of oxidizable impurities from the storage tank would be difficult. Because of these difficulties, sodium hypochlorite is almost always used instead, even though it is less effective, and even though it results in increased chlorine contamination of the environment.
The present invention recognizes that liquid precursors of chlorine dioxide can be stored for relatively lengthy time periods without losing their potency. Further, these liquid precursors can be mixed to form chlorine dioxide immediately prior to injection into a waste stream, in a continuous process. Chlorine dioxide can be produced by the combination of sodium chlorite with a strong mineral acid, such as hydrochloric acid, or with a weak organic acid, such as citric acid. The use of a strong acid tends to produce high concentrations of chlorine dioxide more rapidly, and the process tends to be more difficult to control. Treatment of medical waste requires very low concentrations of chlorine dioxide produced in a slow and predictable manner. Therefore, the best choice for treatment of medical waste is the combination of sodium chlorite with a weak organic acid, such as citric acid. The resulting reaction is slow and predictable, and it is easily mediated by controlling the temperature of the solution.
The resulting solution can be used in a very low concentration to decontaminate infectious waste, if used in a system that mechanically reduces the particle size of the waste to the appropriate size. The present invention also recognizes the necessity for the correct interaction of certain critical structural features in the waste processing apparatus, to achieve the necessary intimate contact between the low concentration of chlorine dioxide and the waste material, and to properly handle the waste material to allow the conservative use of the chlorine dioxide.
Accordingly, it is an object of the present invention to provide a system for waste treatment in which chlorine dioxide precursors are appropriately mixed and then immediately blended with infectious waste to decontaminate the waste, while preventing excessive decomposition of the disinfectant, and while preventing any explosion hazard. Another object of the present invention is to provide a system for waste treatment which results in the reduction of waste particle size to an appropriate size to allow effective use of the disinfectant in a low concentration, while preventing clogging of the waste stream and while maximizing the recycling of the disinfectant. Finally, it is an object of the present invention to provide a system for waste treatment which is relatively easy and comparatively cost-effective to implement.
SUMMARY OF THE INVENTION
The present invention is a system for treating infectious waste comprising a series of continuous treatment stages. The multi-stage treatment system has an inlet stage at its front end which comprises an opening for receiving the infectious waste. The waste may be fed in any form through the opening, but in a preferred embodiment, the opening is sized to receive a sealed plastic bag in which the waste is packaged. The bags are fed through the opening into the system in their entirety. In this manner, waste handlers operating the present system need never come in direct contact with the infectious waste. The waste bag has a primary compartment containing the infectious waste, and it can have one or more secondary prefilled and sealed compartments containing other process additives in isolation from the waste, all of which are to be introduced into the system. As will be seen below, the entire contents of the bag are released from the bag and commingled during operation of the treatment system.
The inlet opening leads to a fragmenting chamber positioned therebelow, which encloses the shredding, wetting, and granulating stages of the system. The waste drops under the force of gravity from the inlet stage down into the shredding stage which comprises a plurality of opposingly rotating shredder blades. The shredding blades destroy the waste bag, spilling its contents into the fragmenting chamber. Any process additives contained in the bag become mixed with the waste in the shredding stage. The blades also function to break up any large frangible waste into small size particles.
The wetting stage is positioned immediately beneath the shredding stage to wet the small particle size shredded waste with the liquid chlorine dioxide treatment solution, as the waste falls through the shredding blades. The liquid disinfectant will more thoroughly mix with the waste material as the waste passes farther through the system. The wetting stage comprises a plurality of jets through which the liquid disinfectant is pumped, with the jets being positioned at the interior walls of the fragmenting chamber immediately beneath the shredding blades. The jets are directed radially into the chamber and are capable of producing a controlled spray of the liquid disinfectant into the waste mixture. The liquid disinfectant is preferably an aqueous chlorine dioxide solution containing some gaseous chlorine dioxide, which has been formed by the continuous mixing of liquid sodium chlorite and citric acid immediately prior to injection through the jets. The liquid disinfectant is also maintained at an elevated temperature immediately prior to injection. The temperature of the disinfectant is controlled according to the measured chlorine dioxide concentration in gas stripped from the solution. The heated liquid is then injected, to uniformly contact the falling waste mixture to form a hot mash. While the present invention in its preferred embodiment makes possible the use of chlorine dioxide as the disinfectant, the apparatus can be used with other disinfectants without departing from the spirit of the invention.
The granulating stage is provided beneath the wetting stage and comprises a plurality of specially designed blades mounted on a shaft so as to be rotatable against a plurality of stationary blades mounted on the walls of the fragmenting chamber to form cutting surfaces. The granulating blades rotate in a radial plane which is substantially parallel to the flow of the mash. At the cutting surfaces, the granulating blades break up the already small particle size waste into yet smaller particle sizes, to insure intimate contact between the treatment chemical and the waste material, and to cut any fibrous material which has not been previously fragmented by the shredding blades. The granulator blades are designed to allow the use of a plurality of cutting edges as the edges wear as a result of contact with hard materials. The blades also fully mix the components of the waste mash, thereby ensuring that the disinfectant chemicals in the liquid medium adequately contact the waste material to achieve the necessary kill rate with a relatively low concentration of the chemical.
A granulator is used instead of a hammer mill, because a hammer mill will not consistently and efficiently reduce the particle size of non-brittle materials, which constitute the majority of the medical waste stream. When such soft materials are passed through a hammer mill, the materials tend to pass through in crumpled form, rather than having a reduced particle size. This results in reduced contact between the disinfectant and the waste material.
A granulator is used at this stage instead of a shredder, because a shredder produces long strips of material. The strips tend to clog the shredder if used with a sizing screen, and they tend to become folded in accordion folds, thereby reducing contact between the disinfectant and the waste material. A shredder can also pass relatively large items unscathed. If a sizing screen were used downstream of a shredder at this point, it would quickly clog.
The output of the granulating stage is preferably fully wetted by the disinfectant solution, and it has a smaller granular particle size than the output of the shredding stage. The granulating stage is also designed with a sizing screen interacting with the specially designed blades to insure that the waste material is repeatedly cut and separated. The blades tend to press outwardly on the waste material in addition to cutting it, partially forcing the waste material through the screen. The blades also drag waste material cross the surface of the screen, thereby dispersing any tightly packed clumps of the material. This insures that the waste material does not clog the screen, and that it is reduced to the appropriate size to achieve thorough contact with the disinfectant, thereby allowing use of the desired low concentration of chemical.
The outlet from the fragmenting chamber incorporates the aforementioned screen functioning in cooperation with the granulating blades. The screen is sized to allow a selected smaller granular particle size waste to fall through the screen into a disinfectant reactor chamber below, while retaining any waste which has not been sufficiently granulated in the granulating stage. Waste which is retained by the screen is scooped up by the granulating blades rotating against the screen and returned to the associated cutting surfaces for additional particle size reduction until the waste is sufficiently small to pass through the screen. Up to this point substantially all of the work to convey the waste through the above-recited stages is performed by gravity.
The granulating stage is followed by the disinfecting stage. The disinfecting stage comprises a disinfectant reaction chamber preferably integral with an auger. The auger has two ends; a liquid medium collection tank and inlet port are at one end of the auger and a disinfected solid waste discharge port is at the other end. The auger is inclined upwardly to convey the waste from the inlet port to the disinfected solid waste discharge port. The length of the auger wherein the disinfection reaction occurs constitutes the disinfectant reaction chamber. The disinfection reaction is preferably completed by the time the waste reaches a point about two-thirds up the auger incline. The controlled rate at which the auger screw carries the waste up the incline to the discharge port enables a sufficient residence time for disinfection of the waste.
The disinfecting stage is combined with a dewatering stage. The dewatering stage comprises a conical flow restriction immediately prior to the discharge port. Although some of the liquid medium is removed from the waste by gravity at the lower end of the auger, the bulk of the liquid medium is removed from the waste by compressing the mash through the flow restriction. The final exit from the auger is positioned at or slightly beyond the point at which the conical flow restriction begins. The conical flow restriction is constructed with a critical restriction angle best suited to dewater the waste being treated. When these features are combined with the proper granulating of the waste, and when the waste is free of long strips, a high degree of dewatering will result without resulting in clogging of the discharge path. The auger is also sloped at a critical angle best suited to assist in dewatering while avoiding clogging. The combination of the pressure rise in the mash resulting from the conical restriction, and the pressure rise resulting from the angle of the auger, yield a compression of the waste material which achieves the maximum dewatering efficiency without resulting in clogging.
The liquid medium driven from the waste mash exits the auger through perforations or a screen in the housing surrounding the auger, and the liquid is collected and passed to the heated disinfectant mixing tank for recycling to the wetting stage. The screen in the auger housing is shaped to conform to the radial edges of the auger, so that as the auger turns it continually scrapes compacted waste material from the screen. This prevents clogging of the screen. The liquid to be recycled is passed through a cyclone separator designed to remove heavy fines or other material prior to return of the liquid to the jets. The heavy fines or other material can be periodically dumped from the cyclone separator onto the waste material in the auger.
In operation, process control for the present system is provided by regulating the disinfectant concentration in the system and the liquid medium temperature. Temperature is related to the rate of liquid medium flow, and heater and auger operating parameters. The above-described system satisfies the present objective of providing an infectious waste treatment apparatus which contacts an infectious waste with precise amounts of a disinfectant to disinfect the waste while simultaneously fragmenting the waste to reduce its bulk volume. The system also provides an infectious waste disposal apparatus which is relatively easy and comparatively cost-effective to implement and operate.
The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the multi-stage waste treatment apparatus of the present invention;
FIG. 2 is a view of the shredding stage of the apparatus of FIG. 1, along line 2--2;
FIG. 3 is a schematic view of the apparatus of FIG. 1;
FIG. 4 is a section view of an alternate embodiment of the waste outlet flow restriction;
FIG. 5 is a schematic of a control unit for the apparatus of the present invention;
FIG. 6 is a generalized curve for the functional relation between disinfectant solution temperature and disinfectant concentration;
FIG. 7 is a schematic view of the granulating stage of the apparatus of FIG. 1;
FIG. 8 is an enlarged view of a portion of FIG. 7, showing the relationship between the blades in the granulating stage;
FIG. 9 is a schematic view of the auger of FIG. 1, with a cyclone separator; and
FIG. 10 is a graph showing an operating range of desired disinfectant temperature versus disinfectant concentration.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIGS. 1 and 3, the infectious waste treatment system of the present invention is generally designated 10. System 10 comprises a plurality of treatment stages including an inlet stage 12, a shredding stage 14, a wetting stage 16, a granulating stage 18, a disinfecting stage 22, and a dewatering stage 24, which define a continuous flowpath for the waste. The terms "disinfect" and "decontaminate" are used synonymously herein and refer to the destruction of a substantial portion of infectious constituents within the infectious waste sufficient to render the waste substantially noninfectious.
Inlet stage 12 comprises an opening 28 at or near the top of a fragmenting chamber 30 which houses stages 14, 16, and 18. Inlet stage 12 opens down into shredding stage 14 at the upper level of fragmenting chamber 30. As shown in FIG. 2, shredding stage 14 comprises multiple pairs of rotatable shredding blades 31a,b, 32a,b, 33a,b. Blades 31a, 32a, 33a, are mounted on shaft 34 and blades 31b, 32b, 33b are mounted on shaft 35 such that blade 31b is rotatably fitted between blades 31a, 32a and so on for all the blades as shown. Each rotatable shredding blade is a disk 36 having a plurality of hook-shaped teeth 37 about the periphery 38 of disk 36. Stationary shredding blades such as 39a, 39b are fixed to chamber walls 40 spaced appropriately from rotatable blades 31a, 32a, 33a and 31b, 32b, 33b to channel waste into the rotatable blades, to reduce the waste particle size to a first selected particle size, and to prevent waste from accumulating in shredding stage 14. The output of waste material from the shredding stage 14 will include some long strips of relatively soft material. Shafts 34, 35 are positioned horizontally and parallel to one another, and the rotatable blades rotate in vertical planes which are substantially parallel to the vertical flowpath of the waste. Shredding action is provided by rotating shaft 34 in the opposite direction from shaft 35.
Referring to FIG. 3, a wetting stage 16 is provided immediately downstream from shredding stage 14. Wetting stage 16 comprises a plurality of liquid disinfectant jets 42a,b,c,d which are mounted in the wall 40 of chamber 30 around the periphery of the waste flowpath and adjacent the bottom side of the shredding blades. A liquid medium feed line is connected to each jet. Thus, as shown in FIG. 1, liquid medium feed lines 46a,b,c,d are connected to jets 42a,b,c,d respectively. Feed lines 46a,b,c, are also connected to a recycle pump 48 across a liquid distribution manifold 50. Pump 48 receives liquid medium from a recycle line 54 connected to a liquid medium collection tank 56 of a recycle stage 26. The manifold 50 is also fed by the output of a disinfectant mixing tank 156. Precursors, or constituents, of the desired disinfectant are fed into the mixing tank 156 through inlet lines 158. The disinfectant thus formulated is then immediately pumped from the mixing tank 156 into the manifold 50 by pump 160 and disinfectant line 162. This arrangement is particularly useful where the desired disinfectant is very volatile, such as chlorine dioxide. The liquid precursors can be sodium chlorite and citric acid. Recycled disinfectant can be fed back into the mixing tank through a recycle line 144. Recycle line 144 can be fed by a cyclone separator as will be discussed later. The mixing tank 156 can be maintained at a selected elevated temperature by heaters in the tank.
If it is desired to remove metals from the waste stream after shredding and wetting, a metal segregating stage 58 may be provided immediately after stages 14, 16. Metal segregating stage 58 comprises a magnet 60 which is mounted in the wall 40 of chamber 30. Magnet 60 contacts the waste as it falls toward granulating stage 18 to segregate the metals therefrom. Access is provided in wall 40 to enable periodic removal of metals from magnet 60.
Granulating stage 18 is positioned at the lower level of fragmenting chamber 30 and comprises a plurality of rotatable granulating blades 62a,b,c,d,e and stationary granulating blades 64a,b. Referring to FIGS. 3, 7, and 8, the rotatable blades 62a,b,c,d,e are mounted on a rotating shaft 66 which in turn is rotatably mounted on chamber wall 40. The rotatable blades have a vertical plane of rotation which is substantially parallel to the vertical flowpath of the waste. The rotatable blades 62a,b,c,d,e are rotatable past stationary granulating blades 64a, 64b, each of which is fixably mounted on opposite sides of chamber wall 40 adjacent rotatable blades 62a,b,c,d,e. As rotatable blades 62a,b,c,d,e rotate, they periodically pass stationary blades 64a,b to form transient cutting surfaces. FIG. 3 shows rotatable blade 62e meeting stationary blade 64b to form transient cutting surface 68. The rotatable and stationary granulating blades are all preferably formed with rectangular cross-sections as shown, so that each blade has four potential cutting edges. FIG. 8 shows the relationship between the cutting edges in more detail. Each blade can be removed and rotated to expose a new cutting edge, until all four edges on each blade have been dulled. As each rotatable blade passes each stationary blade, the clearance between the cutting edges is sufficiently small to granulate the material by a cutting action. The material is then continually passed through the blades until sufficient cuts have been made to reduce the waste material to a selected second, smaller particle size. In addition, all strips of waste material are granulated by this cutting action.
A screening action is accomplished immediately beneath the granulating blades in granulating stage 18. This comprises a screen 70 stretched cross-sectionally across conduit 72 which connects fragmenting chamber 30 and auger 74. Screen 70 has a mesh size which allows particles at or below a given particle size to pass through while preventing particles having a larger particle size than the given particle size from passing through. The movement of the rotatable blades imparts an outward radial motion to the waste material which partially imbeds the waste material in the screen 70. Screen 70 preferably has a 1/2 inch mesh size although other mesh sizes are within the purview of the skilled artisan. Screen 70 is positioned to cooperate with the rotatable granulating blades 62a,b,c,d,e of granulating stage 18. As the rotatable blades rotate, they periodically pass screen 70 to scoop waste retained on screen 70. FIG. 7 shows rotatable blade 62d meeting screen 70 to return waste retained by screen 70 to cutting surface 68.
Disinfecting stage 22 comprises a disinfectant reaction chamber 76 which is integral with auger 74. Auger 74 is inclined upward away from auger inlet 78 to enable precise control of the waste residence time in reaction chamber 76 and to facilitate dewatering as described hereafter. The inclination angle of auger 74 is defined as φ. For a waste stream composed mostly of soft material, such as medical waste, φ is selected between about 10° and 20° and preferably about 15° . This aids in dewatering, without promoting clogging. A lesser angle results in less dewatering capability, while a greater angle appreciably increases the tendency to clog. Reaction chamber 76 is sufficiently sized to hold the throughput of system 10 for a residence time which enables disinfection of the waste before discharge from system 10. Auger 74 has a screw 80 extending axially the entire length of auger 74 which is rotatably mounted therein to carry waste from auger inlet 78 to a waste solid discharge port 86 at the upper end of auger 74.
Dewatering stage 24 is likewise integral with auger 74 and comprises a conical flow restriction 90 at solid disinfected waste discharge port 86. A portion of liquid medium exits auger 74 under gravity through port 82 to collection tank 56 in fluid communication with port 82. A perforated plate 88 is provided at port 82 having a plurality of perforations 89, each significantly smaller than the mesh size of screen 70, and preferably about 1/8 inch, to prevent substantial quantities of waste from exiting auger 74 thereat. However, the primary function of port 82 is to enable fluid intrusion into auger 74 as will be shown.
The conical flow restriction 90 imposes a pressure on the waste material which compacts the material and removes the bulk of liquid medium from the waste before it exits system 10. The auger screw 80 terminates slightly beyond the entrance to the conical restriction 90. In one embodiment the constriction is a conical nozzle 90 having a fixed opening at the end of waste discharge port 86. The angle of the conical restriction 90 is selected according to the content of the waste stream. For a waste stream composed mostly of soft material, such as medical waste, the angle is between 15 and 20 degrees, and preferably about 18 degrees. This ensures sufficient compaction of waste material to achieve dewatering, without clogging the flow path. A lesser angle would significantly detract from the dewatering ability, while a greater angle would significantly increase the tendency to clog. In another embodiment, FIG. 4 shows an adjustable nozzle comprising a pair of doors 92a, 92b, the lower door having a pneumatically biased hinge 93 to render the size of opening 91 pressure responsive. In any case, the restriction applies a compacting force to the disinfected waste before the waste exits the system 10.
Liquid medium driven from the disinfected waste by the compacting force exits auger 74 through perforations 94 in auger housing screen 96. Perforations 94 are sized small enough to restrict the solid waste from the liquid stream. A sleeve 98 around screen 96 at perforations 94 channels the liquid medium into a recycle line 100 which is in fluid communication with the mixing tank 156 through recycle inlet line 144. Before being recycled to the mixing tank 156, as shown in FIG. 9, the liquid is passed through a cyclone separator 140 by means of a pump (not shown). The liquid cycles through the separator 140 to exit into the recycle inlet line 144, after the separation of heavy fines 146 or other materials which fall to the bottom of the separator 140. Periodically, a valve 150 is opened to flush the heavy fines 146 out the outlet 148 of the separator 140 and back onto the waste material on the auger 74.
Collection tank 56 has two chambers 104, 106 in fluid communication with one another, but separated by a weir 108. Port 82 of auger 74 is submerged in primary chamber 104. Secondary chamber 106 receives the overflow of primary chamber 104 and has a recycle outlet port 110 connected to recycle line 54. Heater elements 112, 114 are submerged in primary and secondary chambers 104, 106 respectively for heating the liquid medium as necessary. The collection tank 56 and the mixing tank 156 can be combined as one tank without departing from the spirit of the invention.
FIG. 5 is a schematic for process control of system 10 which is provided by automated control unit 120 in electrical communication with auger 74, heaters 112, 114, recycle pump 48 and door 92b. If a dewatering cone is used, instead of the adjustable door 92b, this connection to the control unit is deleted. Control unit 120 accordingly regulates the speed of auger screw 80, the heat output of heaters 112, 114, the liquid medium recycle rate of pump 48 and the compaction force applied by door 92b to the waste at solid waste discharge port 86. These parameters are regulated in response to the primary input parameters to unit 120 which are the ClO 2 concentration and the temperature of the liquid medium in tank 56. ClO 2 concentration data is provided to unit 120 by means of a conventional air stripper 122 in tank 56 and ClO 2 gas analyzer 124. Temperature data is provided to unit 120 from a conventional temperature sensor 126.
Method of Operation
With cross-reference to the drawings, operation of system 10 in a continuous mode may be seen. System 10 is particularly suited to the treatment of infectious wastes generated by hospitals and other medical facilities. Such wastes are primarily solid wastes consisting of plastic, paper, fabric, glass, and metal and embody a broad range of medical items including syringes, bottles, tubes, dressings, and the like. "Waste treatment" as the term is used herein constitutes fragmenting of the waste to a relatively small granular particle size and disinfecting the waste to render it substantially innocuous and suitable for ordinary landfilling.
The infectious waste is fed through inlet opening 28 into system 10 in any form. In a preferred embodiment, however, the waste is stored in a sealed compartmentalized plastic bag 128 which is then fed through opening 28 into system 10 in its entirety. Waste bag 128 has a primary compartment 130 containing the infectious waste, and the bag can have other prefilled and sealed compartments 132, 134 containing disinfectant chemicals or other process additives, if required. Additives may include dyes, defoamers, or surfactants.
The waste is inserted through inlet opening 28 into the top of fragmenting chamber 30 by an operator. The waste drops under the force of gravity from opening 28 down into opposingly rotating shredding blades 31a,b, 32a,b, 33a,b of shredding stage 14. The shredding blades destroy waste bag 128, spilling the waste and additives into chamber 30 where they are commingled to form a waste mixture. The shredding blades also break up the frangible waste to a small particle size. Wetting stage 16 operates simultaneously with stage 14, whereby the disinfectant jets wet the waste mixture with a stream of a liquid disinfectant. The liquid disinfectant is pumped to the jets from lines 54 and 62 connected to liquid medium collection tank 56 and mixing tank 156. With efficient operation of dewatering stage 24, the bulk of liquid medium in system 10 is recycled. The liquid disinfectant may be within a temperature range between about 0° C. and 100° C. and preferably between about 5° C. and 70° C. The liquid medium has more preferably been preheated above ambient temperature.
The liquid disinfectant uniformly contacts the falling waste mixture to form a wet mash. The mash falls through metal segregating stage 58 where metals are removed and continues falling down into granulating stage 18 where the rotating blades and the stationary blades break up the already small particle size frangible waste into yet a smaller granular particle size which is preferably slightly less than 1/4 inch. The granulating blades also fragment any fibrous material which has not been previously fragmented by the shredding blades, to about the same smaller granular particle size as the frangible material. The granulating blades also more fully mix the mash. Thus, the solids in the resulting mash of granulating stage 18 are preferably fully wetted by the disinfectant solution and the bulk of the solids preferably have a smaller granular particle size which is slightly less than about 1/4 inch. The liquid content of the mash is typically on the order of about 60% by weight.
Upon exiting granulating stage 18, the mash drops onto screen 70 which functions in cooperation with the granulating stage 18 to allow the smaller granular particle size waste to fall through it into disinfectant reaction chamber 76 while retaining any waste in granulating stage 18 which has not been sufficiently fragmented. Waste which is retained by screen 70 is scooped up by the rotating granulating blades rotating against screen 70, and returned to cutting surface 68 for additional particle size reduction until it is sufficiently small to pass through screen 70.
Inlet port 78 receives the waste mash from screening stage 20 and directs the mash to reaction chamber 76 integral with auger 74. The disinfectant solution collected in primary chamber 104 contacts the mash at lower end 84 of auger 74. Auger screw 80 turns continuously to withdraw the mash from lower end 84 at angle φ up the auger incline to solid waste discharge port 86 at a controlled rate which allows a sufficient residence time of the mash in reaction chamber 76. A sufficient residence time is typically on the order of less than about 5 minutes and preferably on the order of about 3 minutes. Auger screw 80 also maintains perforated screen 96 free of waste so that the liquid medium may exit the auger to be recycled. The disinfected and dewatered waste exiting system 10 typically has a liquids content of about 20% by weight in contrast to a liquids content in the mash of about 60% by weight.
The bulk waste volume of the exit waste is on the order of about 15% of the inlet waste. Most of the liquid medium is removed from the waste as the result of compaction caused by fixed nozzle 90 or pressure responsive nozzle 92a,b positioned at waste discharge port 86. The liquid medium exits auger 74 through perforations 94 and is collected in tank 156 for recycling to wetting stage 16 via line 162. Alternatively, collection can be in tank 56. The dual-chamber weir arrangement of tank 56 enables collection of fines in primary chamber 104 for periodic removal.
Process control for system 10 is provided by control unit 120. The decontamination level, i.e., level of kill, attainable in system 10 is a function of several interrelated operating parameters including liquid medium flow parameters and auger and heater operating parameters as shown in FIG. 5. Nevertheless, as is shown below, an operational model of system 10 can be developed as a function of a limited number of key parameters, which are level of kill, disinfectant concentration and temperature.
Accordingly, process control can be effected by selecting a desired level of kill, i.e., target kill, and adjusting the disinfectant concentration and disinfectant solution temperature as a function of the operating parameters to meet the preselected target kill. For example, in theory, a target kill of 6 decades (10 6 organisms/ml) is achieved within about three minutes for a typical infectious medical waste using a chlorine dioxide solution at a concentration of 30 ppm and a temperature of 50° C. In practice, however, the process is controlled by adjusting only temperature while monitoring variations in the disinfectant concentration as a baseline for temperature adjustment. Temperature is selected as the independent variable and disinfectant concentration as the dependent variable for the practical reason that the ability to independently adjust disinfectant concentration is somewhat limited when a fixed amount of precursor is employed, while it is relatively easy to adjust solution temperature via heaters 112, 114. Added amounts of precursors can be provided for process startup, or in the event of process upsets.
The operational model of system 10 recognizes the functional relationship between solution temperature and concentration of the disinfectant, chlorine dioxide, at a given level of kill n. The model is represented by the equation:
[ClO.sub.2 ]=a.sub.n e.sup.-k.sbsp.n.sup.T (1)
wherein
[ClO 2 ]=chlorine dioxide concentration,
T=temperature, and
a n , k n =empirically determined constants for kill n .
FIG. 6 generally depicts the shape of the curve for equation (1). Each point on the curve defines values of [ClO 2 ] and T at which kill n can be achieved. Accordingly, process control is more specifically implemented by preselecting the target kill, empirically determining the model constants at the target kill to define a curve, and adjusting the actual values of [ClO 2 ] and T to lie on the target kill curve.
FIG. 6 shows a typical start-up scenario for system 10. The treatment solution is initially at point A which is inside the required curve for the target kill. Since it is desirable to operate on the curve, automated process control 120 consequently raises the temperature of the solution in tanks 56, 156 toward point B which corresponds to the same chlorine dioxide concentration as point A, but at a higher temperature. Raising the temperature of the solution, however, increases the rate of chlorine dioxide formation, thereby increasing the chlorine dioxide concentration of the solution to a value designated by C on the vertical axis. Thus, as point B is approached, control unit 120 calculates that the required temperature on the curve has fallen. The dashed line shows the iterative equilibration procedure followed by control unit 120 whereby an operating point designated by D is ultimately attained. Operation is preferably maintained along or above the locus of points making up the curve which includes point D.
Chlorine dioxide concentration in tank 56 is continuously monitored by means of air stripper 122 and gas analyzer 124 to enable control unit 120 to determine whether the requirements of the disinfectant solution have changed. For example, if a relatively "dirty" waste is fed to system 10, the amount of ClO 2 consumed increases, reducing the ClO 2 concentration in the solution. Accordingly, control unit 120 must iteratively increase the temperature of the solution in the manner recited above to return operation of system 10 to the curve. If a relatively "clean" waste is fed to system 10, the ClO 2 concentration increases, correspondingly reducing the temperature requirement. Thus, control unit 120 decreases the temperature of the solution. It is preferable to preselect a target kill exceeding a minimum acceptable level of kill so that adequate decontamination of the waste is achieved even when operation falls somewhat below the curve. It has generally been found that within the presently prescribed temperature range a minimum ClO 2 concentration in the treatment solution to achieve an acceptable level of kill is about 10 ppm up to the required concentration and preferably about 12 ppm up to the required concentration.
FIG. 10 shows a typical operating curve which has been found to be effective for practical operation of the apparatus of the present invention. The recommended solution temperature in degrees C is plotted versus the measured chlorine dioxide concentration in ppm. Two curves are shown, reflecting an upper recommended limit and a lower recommended limit, with the area between the curves representing the normal operating area, or system control band. Approximately 3 degrees below the lower recommended limit is an alarm curve. It can be seen from FIG. 10 that the recommended control band for a chlorine dioxide concentration of 30 ppm is between approximately 21 degrees and approximately 41 degrees, with an alarm point at approximately 18 degrees. In fact, the upper recommended temperature limit is 20 degrees above the lower limit for any given concentration. The lower recommended limit curve in FIG. 10 corresponds to the curve shown in FIG. 6.
As noted in the preferred embodiment above, starting quantities of the chlorite salt and acid are fixed. As such, they are preferably provided in stoichiometric excess of quantities necessary to produce the required chlorine dioxide concentrations. Thus, adequate concentrations of liquid precursors will be available in solution for chlorine dioxide production, with equilibrium between the precursors and the reaction products being controlled by tank temperature. A significant fraction of the chlorine dioxide is consumed by reaction with the infectious waste constituents or diffuses out of solution. By way of example, a typical relative starting concentration of precursors, solvent and waste which will provide a desired chlorine dioxide concentration, is on the order of 4.6 g/l sodium chlorite per 3.3 g/l citric acid per 12 kg of solid waste.
While the particular Improved Multi-Stage Infectious Waste Treatment System as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.
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A multi-stage treatment system for infectious waste includes a shredding stage, a granulating stage, a wetting stage, a disinfecting stage, and a dewatering stage which define a continuous treatment flowpath for the infectious waste. A plurality of blades shred the waste in the shredding stage, then the waste is injected with volatile disinfectant chemicals which are mixed immediately before injection. A plurality of blades in a granulating stage then fragment the waste to a smaller particle size. The granulating stage insures that the waste is granulated to a sufficiently small size to facilitate the use of a relatively low concentration of a highly reactive disinfectant. Chemicals are mixed to form a volatile, highly reactive disinfectant which is then immediately injected into the waste downstream of the shredding stage. A plurality of jets wet the waste mixture in the wetting stage with the heated aqueous disinfectant. A flow restriction removes excess aqueous liquid from the disinfected waste in the dewatering stage and renders the product suitable for landfilling. A control system controls the temperature of the disinfectant to maintain an optimum temperature for a desired kill rate.
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TECHNICAL FIELD OF THE INVENTION
[0001] The disclosure relates to cryolite, and in particular to the low-molecular-ratio cryolite for aluminium electrolytic industry and a method for preparing the same.
BACKGROUND OF THE INVENTION
[0002] At present, aluminium electrolytic industry still employs a conventional Hall-Heroult process; electrolyte always takes cryolite-aluminium oxide as a basic system, and the cryolite generally adopts sodium fluoroaluminate. The aluminium electrolytic industry needs an electrolytic temperature of about 960 DEG C and thus power consumption is high, this is mainly because the liquidus temperature of the electrolyte is high and it is necessary to keep a certain temperature of superheat degree to make the aluminium oxide have a better solubility.
[0003] The method for preparing cryolite in industry generally adopts a synthesis method, in which anhydrous hydrofluoric acid reacts with aluminium hydroxide to form fluoaluminic acid; then the fluoaluminic acid reacts with sodium hydroxide or potassium hydroxide at a high temperature; after processes of filtering, drying, melting and crushing, the cryolite is prepared, wherein the cryolite synthesized by this method has a molecular ratio of m=3.0, with a relatively high melting point. The cryolite synthesized by the existing industrial synthesis method has a molecular ratio of m=2.0-3.0, and it is difficult to obtain the relatively pure low-molecular-ratio cryolite containing extremely low water content with a molecular ratio of m=1.0-1.5.
[0004] Therefore, the conventional art has disadvantages that the electrolytic power consumption is high and the electrolyte is not ideal.
SUMMARY OF THE INVENTION
[0005] In order to solve the technical problem existing in the conventional art, the inventor has done a great deal of research in the selection and preparation of electrolyte and unexpectedly finds that taking the mixture of low-molecular-ratio potassium cryolite and low-molecular-ratio sodium cryolite with a certain ratio as the electrolyte of the aluminium electrolytic system can significantly reduce the electrolytic temperature compared with the conventional aluminium electrolytic system which takes sodium cryolite as the electrolyte, and has obvious advantages in corrosion to electrode materials compared with the aluminium electrolytic system which takes single low-molecular-ratio potassium cryolite or low-molecular-ratio sodium cryolite as the electrolyte, but has the electrolytic temperature decrease fallen in between the conventional aluminium electrolytic system which takes sodium cryolite as the electrolyte and the aluminium electrolytic system which takes single low-molecular-ratio potassium cryolite or low-molecular-ratio sodium cryolite as the electrolyte.
[0006] The disclosure provides low-molecular-ratio cryolite for aluminium electrolytic industry, which consists of potassium cryolite and sodium cryolite with a mole ratio of 1:1˜1:3, wherein the molecular formula of the potassium cryolite is mKF.AlF 3 , m=1˜1.5; the molecular formula of the sodium cryolite is nNaF.AlF 3 , n=1˜1.5.
[0007] With the technical scheme above, when the low-molecular-ratio cryolite provided by the disclosure is applied to the aluminium electrolytic industry, the solubility property of aluminium oxide is improved, thus, the electrolytic temperature is reduced, the power consumption is reduced and the electrolytic efficiency is improved.
[0008] As a further improvement of the disclosure, m=1, 1.2 or 1.5; when m=1.0˜1.5; the melting point of the potassium cryolite mKF.AlF 3 is between 540 and 570 DEG C, wherein the melting point of the mKF.AlF 3 slightly increases as the increase of m. n=1, 1.2 or 1.5; when n=1.0˜1.5, the melting point of the nNaF.AlF 3 is between 960 and 1000 DEG C, wherein the melting point of the sodium cryolite nNaF.AlF 3 slightly increases as the increase of n.
[0009] As a further improvement of the disclosure, the mole ratio of the potassium cryolite to the sodium cryolite is 1:1; m=1.5 and n=1.5; the aluminium oxide has a solubility of 13 g/l in the system consisting of potassium cryolite and sodium cryolite with a mole ratio of 1:1 and the electrolytic temperature is between 825 and 900 DEG C.
[0010] Correspondingly, the disclosure also provides a method for preparing the low-molecular-ratio cryolite for aluminium electrolytic industry, which includes the following steps:
[0011] A) putting aluminium into a reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 700 and 850 DEG C, adding potassium fluotitanate, potassium fluoborate or mixture of they two in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain potassium cryolite; putting aluminium into another reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 700 and 850 DEG C, adding sodium fluotitanate, sodium fluoborate or mixture of they two in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain sodium cryolite; and
[0012] B) mixing the obtained potassium cryolite with the obtained sodium cryolite in a mole ratio of 1:1˜1:3.
[0013] The preparation method provided by the disclosure has advantages of mild reaction conditions, easy control, simple process, full reaction and high quality of reaction product.
[0014] As a further improvement of the disclosure, the method for preparing the low-molecular-ratio cryolite for aluminium electrolytic industry includes the following steps:
[0015] A) putting aluminium into a reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 780 and 850 DEG C, adding potassium fluotitanate in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain potassium cryolite of which the molecular formula is
[0000]
3
2
KF
·
AlF
3
;
[0000] putting aluminium into another reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 780 and 850 DEG C, adding sodium fluotitanate in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain sodium cryolite of which the molecular formula is
[0000]
3
2
NaF
·
AlF
3
;
[0000] and
[0016] B) mixing the obtained potassium cryolite with the obtained sodium cryolite in a mole ratio of 1:1˜1:3, wherein the reaction formula involved is:
[0000]
3
4
K
2
TiF
6
+
Al
=
3
4
Ti
+
3
2
KF
·
AlF
3
;
3
4
Na
2
TiF
6
+
Al
=
3
4
Ti
+
3
2
NaF
·
AlF
3
.
[0017] As a further improvement of the disclosure, the method for preparing the low-molecular-ratio cryolite for aluminium electrolytic industry includes the following steps:
[0018] A) putting aluminium into a reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 700 and 850 DEG C, adding potassium fluoborate in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain potassium cryolite of which the molecular formula is KF.AlF 3 ; putting aluminium into another reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 700 and 850 DEG C, adding sodium fluoborate in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain sodium cryolite of which the molecular formula is NaF.AlF 3 ; and
[0019] B) mixing the obtained potassium cryolite with the obtained sodium cryolite in a mole ratio of 1:1˜1:3, wherein the reaction formula involved is:
[0000] KBF 4 +Al=B+KF.AlF 3 ; NaBF 4 +Al=B+NaF.AlF 3 .
[0020] As a further improvement of the disclosure, the method for preparing the low-molecular-ratio cryolite for aluminium electrolytic industry includes the following steps:
[0021] A) putting aluminium into a reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 700 and 850 DEG C, adding the mixture of potassium fluoborate and potassium fluotitanate with a mole ratio of 2:1 in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain potassium cryolite of which the molecular formula is
[0000]
6
5
KF
·
AlF
3
;
[0000] putting aluminium into another reactor, injecting an inert gas to the reactor after vacuumizing, heating the reactor to a temperature of between 700 and 850 DEG C, adding the mixture of sodium fluoborate and sodium fluotitanate with a mole ratio of 2:1 in the reactor and stirring for 4 to 6 hours, pumping the superstratum melt liquid to obtain sodium cryolite of which the molecular formula is
[0000]
6
5
NaF
·
AlF
3
;
[0000] and
[0022] B) mixing the obtained potassium cryolite with the obtained sodium cryolite in a mole ratio of 1:1˜1:3, wherein the reaction formula involved is:
[0000]
K
2
TiF
6
+
2
KBF
4
+
10
3
Al
=
TiB
2
+
10
3
[
6
5
KF
·
AlF
3
]
;
Na
2
TiF
6
+
2
NaBF
4
+
10
3
Al
=
TiB
2
+
10
3
[
6
5
NaF
·
AlF
3
]
.
[0023] As a further improvement of the disclosure, the method for preparing the low-molecular-ratio cryolite for aluminium electrolytic industry includes the following steps:
[0024] A) putting excessive aluminium into a reactor, heating the reactor to a temperature of between 700 and 850 DEG C, adding the mixture of potassium fluoborate and potassium fluotitanate with a mole ratio of y:x in the reactor and stirring for 0.5 to 6 hours, pumping the superstratum melt liquid to obtain potassium cryolite of which the molecular formula is
[0000]
3
y
+
6
x
3
y
+
4
x
KF
·
AlF
3
;
[0000] putting excessive aluminium into another reactor, heating the reactor to a temperature of between 700 and 850 DEG C, adding the mixture of sodium fluoborate and sodium fluotitanate with a mole ratio of y:x in the reactor and stirring for 0.5 to 6 hours, pumping the superstratum melt liquid to obtain sodium cryolite of which the molecular formula is
[0000]
3
y
+
6
x
3
y
+
4
x
NaF
·
AlF
3
;
[0000] and
[0025] B) mixing the obtained potassium cryolite with the obtained sodium cryolite in a mole ratio of 1:1˜1:3, wherein the reaction formula involved is:
[0000]
K
2
TiF
6
+
KBF
4
+
Al
Al
·
Ti
·
B
+
3
y
+
6
x
3
y
+
4
x
KF
·
AlF
3
;
Na
2
TiF
6
+
NaBF
4
+
Al
Al
·
Ti
·
B
+
3
y
+
6
x
3
y
+
4
x
NaF
·
AlF
3
.
[0026] Compared with the conventional art, the disclosure achieves advantages as follows: when the low-molecular-ratio cryolite provided by the disclosure is applied to the aluminium electrolytic industry, the solubility property of aluminium oxide is improved, thus, the electrolytic temperature is reduced; and compared with the aluminium electrolytic system which takes the conventional cryolite or single low-molecular-ratio potassium cryolite or single low-molecular-ratio sodium cryolite as the electrolyte, the electrolytic temperature is obviously different and the corrosion to electrode materials is different too; the method provided by the disclosure for preparing the low-molecular-ratio cryolite has advantages of mild reaction conditions, easy control, simple process and full reaction.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] The disclosure is described below in further detail through specific embodiments.
Embodiment 1
[0028] Weighing 1 ton of aluminium and putting it into a reactor, injecting argon to the reactor for protection after vacuumizing, heating the reactor to a temperature of 800 DEG C, adding dried potassium fluotitanate in the reactor slowly in accordance with a reaction ratio and stirring quickly for 5 hours to form titanium sponge and potassium cryolite
[0000]
(
3
2
KF
·
AlF
3
)
,
[0000] opening the cover of the reactor, pumping the superstratum melt liquid potassium cryolite through a siphon-pump. Weighing 1 ton of aluminium and putting it into another reactor, injecting argon to the reactor for protection after vacuumizing, heating the reactor to a temperature of 800 DEG C, adding dried sodium fluotitanate in the reactor slowly in accordance with a reaction ratio and stirring quickly for 5 hours to form titanium sponge and sodium cryolite
[0000]
(
3
2
NaF
·
AlF
3
)
,
[0000] opening the cover of the reactor, pumping the superstratum melt liquid sodium cryolite through a siphon-pump.
[0029] Mixing the prepared potassium cryolite
[0000]
(
3
2
KF
·
AlF
3
)
,
[0000] with the prepared sodium cryolite
[0000]
(
3
2
NaF
·
AlF
3
)
,
[0000] in a mole ratio of 1:1 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 850 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
Embodiment 2
[0030] Weighing 1 ton of aluminium and putting it into a reactor, injecting argon to the reactor for protection after vacuumizing, heating the reactor to a temperature of 780 DEG C, adding dried potassium fluoborate in the reactor slowly in accordance with a reaction ratio and stirring quickly for 5 hours to form boron and potassium cryolite (KF.AlF 3 ), opening the cover of the reactor, pumping the superstratum melt liquid potassium cryolite through a siphon-pump. Weighing 1 ton of aluminium and putting it into another reactor, injecting argon to the reactor for protection after vacuumizing, heating the reactor to a temperature of 780 DEG C, adding dried sodium fluoborate in the reactor slowly in accordance with a reaction ratio and stirring quickly for 5 hours to form boron and sodium cryolite (NaF.AlF 3 ), opening the cover of the reactor, pumping the superstratum melt liquid sodium cryolite through a siphon-pump.
[0031] Mixing the prepared potassium cryolite (KF.AlF 3 ) with the prepared sodium cryolite (NaF.AlF 3 ) in a mole ratio of 1:1 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 825 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
Embodiment 3
[0032] Weighing 1 ton of aluminium and putting it into a reactor, injecting argon to the reactor for protection after vacuumizing, heating the reactor to a temperature of 750 DEG C, adding the mixture of dried potassium fluoborate and potassium fluotitanate in the reactor slowly in accordance with a reaction ratio, wherein the mole ratio of the potassium fluoborate to the potassium fluotitanate is 2:1; stirring quickly for 5 hours to form titanium boride and potassium cryolite
[0000]
(
6
5
KF
·
AlF
3
)
,
[0000] opening the cover of the reactor, pumping the superstratum melt liquid potassium cryolite through a siphon-pump. Weighing 1 ton of aluminium and putting it into a reactor, injecting argon to the reactor for protection after vacuumizing, heating the reactor to a temperature of 750 DEG C, adding the mixture of dried sodium fluoborate and sodium fluotitanate in the reactor slowly in accordance with a reaction ratio, wherein the mole ratio of the sodium fluoborate to the sodium fluotitanate is 2:1; stirring quickly for 5 hours to form titanium boride and sodium cryolite
[0000]
(
6
4
NaF
·
AlF
3
)
,
[0000] opening the cover of the reactor, pumping the superstratum melt liquid sodium cryolite through a siphon-pump.
[0033] Mixing the prepared potassium cryolite
[0000]
(
6
5
NaF
·
AlF
3
)
[0000] with the prepared sodium cryolite
[0000]
(
6
5
NaF
·
AlF
3
)
[0000] in a mole ratio of 1:1 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 825 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
Embodiment 4
[0034] Mixing the prepared potassium cryolite (KF.AlF 3 ) with the prepared sodium cryolite
[0000]
(
6
5
NaF
·
AlF
3
)
[0000] in a mole ratio of 1:3 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 850 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
Embodiment 5
[0035] Mixing the prepared potassium cryolite
[0000]
(
3
2
KF
·
AlF
3
)
[0000] with the prepared sodium cryolite (NaF.AlF 3 ) in a mole ratio of 1:3 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 850 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
Embodiment 6
[0036] Mixing the prepared potassium cryolite
[0000]
(
6
5
KF
·
AlF
3
)
[0000] with the prepared sodium cryolite
[0000]
(
3
2
NaF
·
AlF
3
)
[0000] in a mole ratio of 1:3 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 850 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
Embodiment 7
[0037] Weighing 5 tons of aluminium and putting it into a reactor, heating the reactor to a temperature of 750 DEG C, adding 2 tons of mixture of dried potassium fluoborate and potassium fluotitanate in the reactor slowly, wherein the mole ratio of the potassium fluoborate to the potassium fluotitanate is 1:1; stirring quickly for 4 hours to form aluminium-titanium-boron alloy and potassium cryolite
[0000]
(
9
7
KF
·
AlF
3
)
[0000] due to excessive aluminium, opening the cover of the reactor, pumping the superstratum melt liquid potassium cryolite through a siphon-pump. Weighing 5 tons of aluminium and putting it into a reactor, heating the reactor to a temperature of 750 DEG C, adding 2 tons of mixture of dried sodium fluoborate and sodium fluotitanate in the reactor slowly, wherein the mole ratio of the sodium fluoborate to the sodium fluotitanate is 1:1; stirring quickly for 4 hours to form aluminium-titanium-boron alloy and sodium cryolite
[0000]
(
9
7
NaF
·
AlF
3
)
[0000] due to excessive aluminium, opening the cover of the reactor, pumping the superstratum melt liquid sodium cryolite through a siphon-pump.
[0038] Mixing the prepared potassium cryolite
[0000]
(
9
7
KF
·
AlF
3
)
[0000] with the prepared sodium cryolite
[0000]
(
9
7
NaF
·
AlF
3
)
[0000] in a mole ratio of 1:3 and applying the cryolite mixture to the aluminium electrolytic industry, wherein the electrolytic temperature can be controlled in a range of between 850 and 900 DEG C, and virgin aluminium can be obtained by using inert electrode materials or carbon electrode materials or mixed (combination of carbon and inert electrode materials) electrode materials to carry out electrolysis.
[0039] The above are the further detailed description of the disclosure made in conjunction with specific preferred embodiments; it can not be considered that the specific embodiment of the disclosure is only limited to the description above. For the common technicians in the technical field of the disclosure, empty simple deductions or substitutes can be made without departing from the concept of the disclosure and they are deemed to be included within the scope of protection of the disclosure.
|
The disclosure provides low-molecular-ratio cryolite for aluminium electrolytic industry, which consists of potassium cryolite and sodium cryolite with a mole ratio of 1:1˜1:3, wherein the molecular formula of the potassium cryolite is mKF.AlF 3 and the molecular formula of the sodium cryolite is nNaF.AlF 3 , where m=1˜1.5 and n=1˜1.5. When the low-molecular-ratio cryolite provided by the disclosure is applied to the aluminium electrolytic industry, electrolytic temperature and power consumption can be reduced and electrolytic efficiency is improved.
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FIELD OF THE INVENTION
This application relates to fire deterrent systems and, in particular, to a computer based system that provides preemptive protection for structures that are in impending danger from an approaching fire when these structures are located in a wildfire zone.
PROBLEM
It is a problem for rural homeowners to protect their property from the danger of wildfires. There is an increasing trend for people to build their homes in locations that are within what is called the wildland/urban interface. This is a term that describes the border zone where structures, mainly residences, are built in wildland areas that by nature are subject to fires. The wildland/urban interface describes the geographical areas where formerly urban structures, mainly residences, are built in close proximity to flammable fuels naturally found in wildland areas, including forests, prairies, hillsides and valleys. To the resident, the forest represents a beautiful environment but to a fire the forest represents a tremendous source of fuel. Areas that are popular wildland/urban interfaces are the California coastal and mountain areas and the mountainous areas in Colorado (among others).
Residences built in these areas tend to be placed in locations that contain significant quantities of combustible vegetation and the structures themselves have combustible exterior walls and many have untreated wood roofs. Many of these houses are also built on sloping hillsides to obtain scenic views; however, slopes create natural wind flows that increase the spread of a wildfire. These homes are also located a great distance away from fire protection equipment and typically have a limited water supply, such as a residential well with a minimal water flow in the range of one to three gallons per minute.
Given this collection of factors, a wildfire entering this area is very difficult to control. Wildfire can reach an intensity that causes uncontrollable and rapid spread due to spotting, which occurs as wind-borne burning embers are carried far ahead of the main fire front and land in receptive fuels. These embers can fall on the roofs of houses, on woodpiles or can start new fires in the vegetation surrounding a structure while firefighters are occupied elsewhere with the main fire.
All prior art residential firefighting systems are grossly inadequate to deal with wildfires in the wildland/urban interface area. One of the most significant failings of all of these prior art fire fighting systems is that they are reactive by nature and serve to attempt to extinguish a fire that has begun on the roof of a structure. Due to the limited supply of water in the homes in a wildland/urban interface, such a method of defense is impractical as it can deliver a very limited amount of water to the structure that is ablaze. In addition, the intensity of a wildfire quickly overwhelms these limited fire extinguishing measures since they are activated once the structure is on fire and/or the wildfire has reached the structure. Nine of these prior art systems operate in a preemptive manner nor provide any environmental dependent measures to prevent the initiation of the fire or to thwart its spread.
Therefore, there presently exists no viable fire control system for residences in the wildland/urban interface and the magnitude and number of losses due to wildfires in these areas continue to increase at a significant rate on a yearly basis. There is a critical need for a fire prevention system that operates in a preemptive manner to effectively prevent the ignition and spread of fires that occur in these wildland/urban interface areas.
SOLUTION
The above described problems are solved and a technical advance achieved in the field by the fire deterrent system of the present invention. This fire deterrent system operates in a proactive manner by detecting the impending approach of a wildfire within the vicinity of the structure to be protected. This system includes apparatus to identify the locus, magnitude and direction of spread of a fire while it is still outside of a defensive perimeter that encircles the residence and extends outward therefrom. The impending arrival of a wildfire is sensed by this apparatus and defensive measures are taken in a preemptive manner in order to prevent the ignition of a fire within this defensive perimeter rather than attempting to extinguish fires once they have already ignited, which as experience shows is a futile measure in a wildfire. This apparatus includes an infrared, ultraviolet or electro-optical fire detector to detect the presence of a fire in the immediate vicinity of the residence. The apparatus further includes an anemometer to measure the wind magnitude and direction at the home site as well as a plurality of sensors sited at various locations around the defensive perimeter to detect the ignition of fires within this defensive perimeter. A computer based controller is used to monitor the water level in a storage tank and to control activation of a plurality of water delivery systems that function to apply water to the surrounding vegetation, the roof of the structure, the walls of the structure and any other site-specific locations that are required to prevent the ignition of a fire in this defensive perimeter. The water is preemptively applied to various combustible materials located within this defensive perimeter prior to the arrival of the fire in order to prevent these combustible materials contained from igniting due to burning embers that are wind-borne from the approaching fire. Therefore, this apparatus reduces the susceptibility of all combustible elements within the defensive perimeter to ignition to significantly decrease the fire danger to the residence and the surrounding vegetation. The computer based controller monitors water supply, wind velocity, locus and direction of the fire to sequentially and periodically activate various water delivery systems to maximize the protection effectiveness of the limited water resources that are available to the homeowner in the wildland/urban interface. This apparatus also includes a water recovery system in order to reuse the water that is applied to the roof and walls of the structure to reduce the need for water from the limited water supply. A manual access panel is also optionally provided so the system can be operated by homeowner, fire department personnel, police, etc. The computer provides all pertinent system information to operator so the panel can be used to modify system parameters or control activation of the system. This system can also be activated by homeowner from a remote location by means of a touch-tone phone connection to a telephone access port on the computer.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates an overview of a typical site in the wildland/urban interface area indicative of the structures contained therein and the primary elements of the apparatus of this fire protection system;
FIG. 2 illustrates in block diagram form a number of the primary architectural features of this apparatus;
FIGS. 3-5 illustrate in flow diagram form the operational steps taken by the controller in this apparatus to defend the residence from an impending wildfire.
DETAILED DESCRIPTION
There is an increased incidence of home building in the area defined as the wildland/urban interface. This area is where residences are built in close proximity to the flammable fuels naturally found in wildland areas, including forests, prairies, hillsides and valleys. These areas typically represent the confluence of a plurality of factors that render firefighting difficult, if not impossible. The primary factor is combustible vegetation which is found in abundance in these areas. An approaching fire ignites the surrounding vegetation in a step by step attack on a home and may reach intensities that render conventional firefighting methods ineffectual. In particular, when the fire reaches an intensity of 500 btu per foot of fire line front per second of burning, the fire is considered to be beyond control by use of organized means. Beyond 1000 btu per foot per second a fire can be expected to feature dangerous spotting, fire whirls, crowning and major runs with high rates of spread and violent fire behavior. Spotting is particularly difficult to deal with since it occurs as wind borne burning embers are carried far ahead of the main fire front. These embers land in receptive fuels and can fall on the roofs of homes or woodpiles and start new fires far in advance of the fire line front.
In addition, many of the structures built in these rural areas are constructed of materials that are highly susceptible to fires. Primary among these are untreated wood roofs such as untreated wood shingles or wood shake roofing. Furthermore, these structures have combustible exterior walls or affiliated wood structures such as decks and woodpiles located under decks or placed too close to the structure. Many of the structures are located on a slope which creates a natural windflow that increases the speed of a wildfire by creating a chimney effect. The remote location of these structures impedes the ability of fire protection equipment to reach the site of a fire. Finally, there is typically a significant lack of water available for firefighting purposes. There are no hydrants or ponds and a fire tanker truck must respond to the site of the fire in order to provide a source of water for firefighting purposes. These structures typically have a domestic water supply that consists of a well of limited volumetric capacity. Therefore, the confluence of many or all of these factors make firefighting in this environment difficult at best.
System Architecture
FIGS. 1 and 2 illustrate a typical residential structure located in a wildland/urban interface zone. FIG. 1 illustrates an aerial view of the residence R and its surroundings, while FIG. 2 illustrates a side perspective view thereof. In order to simplify FIGS. 1 and 2, the pipes interconnecting many of the water delivery systems are not shown, nor are the electrical conductors that connect the computer 1 to the various sensors, control valves, etc. A limited number of sprinklers are shown in these drawings to clearly illustrate the concepts of this invention and it is understood that the number, placement and interconnection of these elements are highly site-specific and variable.
In FIG. 1, the residence R and its surroundings are encircled by a defensive perimeter 100 which is divided into a plurality of sectors (labeled A-I), each which represents a position of the defensive zone for fire protection purposes. While these sectors A-I are drawn in a rectilinear manner on FIG. 1, it is obvious that these can be arbitrarily shaped sectors and are selected as a function of the topology of the surrounding land, the vegetation present on the land and the particular characteristics of the residence and its outlying structures. For the sake of simplicity, the sectors A-I are drawn as square boxes on FIG. 1. The residence R and its immediate surroundings are located in sector E, which sector is completely surrounded by peripheral defensive sectors A-D, F-I which extend outwardly from sector E. Sector A includes in the upper lefthand corner thereof a steep slope 21 that descends away from the residence and represents a significant wildfire threat if a fire should initiate at the base of incline 21. Furthermore, dense shrubs are located at the top of incline 21 and serve to intensify the fire danger. Each of the sectors A-I illustrated in FIG. 1 includes at least one remote sensor 12 that senses the immediate presence of an ignited fire. These are heat sensors of conventional design and provide data to a centralized computer 1 which is located within the residence R to indicate that the fire has entered one of the sectors of the defensive perimeter A-D, F-I outlying the residential sector E.
System Architecture--Water Application Apparatus
FIG. 2 illustrates a side view of residential structure R, including a below grade 102 view of the pipes 18 that supply sprinklers 11 with water. Included in the fire deterrent apparatus is a holding tank 7 that stores a large quantity of fire retardant fluid that is used by this system to proactively prevent the ignition and spread of fire in the defensive sectors and on the structure illustrated herein. Holding tank 7 is supplied by a water source 5 which typically is a domestic well but which also can be supplemented by a pond, swimming pool or any other reservoir nearby. Diversion valve 6 interconnects water source 5 with holding tank 7 and is electrically activated by computer 1 to maintain a predetermined level of fluid within holding tank 7. Similarly, a recovery valve 8 is provided in order to recycle any water that is applied to the residential structure R back to holding tank 7 in order to minimize the requirement for supplemental water from the water source 5, which has a limited volumetric output. Recovery valve 8 is connected to a series of recovery pipes which can be as simple as interconnecting the downspouts from the existing house gutter system with recovery valve 8 in order to recycle any water that is applied to the roof of the structure R. The water recovery system can also include open troughs at the bottom of the walls in order to capture any water that is sprayed on the side of the structure R for recycling to recovery valve 8 into holding tank 7. A supplemental source of power such as generator 3 is provided to guarantee a source of electricity to operate the valves, water pumps, computer system sensors, and generator 3 is activated in the event that there is a loss of power from the utility company.
A fire detection sensor 2 is used by the system in order to sense the presence of a wildfire in the region around the structure and its defensive perimeter. The sensor is typically an infrared, electro-optical or ultraviolet sensor 2 mounted on the peak of the roof and has an omni directional (360°) sensing capability that detects the presence of a fire up to 1 kilometer away from its location. In addition, an anemometer 10 is provided in order to identify the ambient wind velocity which affects the spread of the fire and the strategy of fire prevention that this system needs to implement. The apparatus used to preemptively defend against the spread of wildfire includes a plurality of sprinklers 11 that are strategically placed to spray the vegetation surrounding the structure R with a fire retardant fluid (such as water) in order to impede the spread of the fire. Sprinklers 14 also can be optionally included to spray the trees 13 in order to prevent airborne embers from igniting this particular vegetation. Trees are susceptible to the intense radiation caused by an approaching wildfire and application of water to the trees, especially in drought conditions, significantly deters the spread of radiant ignited fires. Sprinklers 15, 17 are also included on the roof and walls of the structure R and sprinklers 16 are preferably mounted on the outlying annexes thereto such as decks in order to direct a spray of the fire retardant fluid on the roof and walls of the structure R as well as its decks, wooden walkways, shrubbery, etc. The various sprinklers 11, 14-17 are supplied with water from pressure tank 9 via supply pipes 18-20, 24 only a few of which are shown. It should also be noted that the term "sprinkler" is understood to include all types of apparatus that would apply water to an object in a manner, volume, area desirable for the stated purpose including seeper hoses, etc.
This fire deterrent apparatus operates in a proactive manner with a knowledge based system in order to apply the limited fire retardant resources in the most beneficial manner to the structure R and its surrounding vegetation to impede the progress of an approaching fire. The use of a plurality of sectors A-I within the predetermined defensive perimeter 100 enables the computer system to maximize the application of the fire retardant fluid on the surrounding vegetation and on the structure R in the sector most directly in the path of the approaching fire. Depending on availability of fire retardant fluid in holding tank 7, the ambient wind conditions, and speed of approaching fire, computer system 1 can focus all of the fire prevention measures into a predetermined sector or may activate fire prevention measures in a plurality of the sectors, with a different intensity in each sector depending on the nearness of the sector to the approaching fire. In this manner, weighted or site-specific fire prevention measures are initiated on a sector by sector basis.
Operational Program--Fire Detection
FIGS. 3-5 illustrate in flow diagram form the primary operational steps taken by the fire prevention program resident on computer system 1 in order to controllably activate the various sprinklers 11, 14-17, pumps 4, generators 3 and other apparatus that comprise this system. At step 301, sensor 2 detects the presence of a wildfire within the vicinity of the structure R to be defended. Sensor 2 operates on an interrupt basis causing the computer system 1 to initiate the deterrent portion of the defensive program at step 302. Alternatively, the computer system 1 can be activated by a user via a telephone dial up port on computer system 1 or via a manual access panel which can be located on the exterior of structure R to enable firefighting personnel to activate the system. At step 303, the electrical generator 3 (if provided) is activated to ensure a constant source of power for the fire deterrent apparatus. At step 304, the water valves 6, 8 are activated and data is received from one of the continuously running programs resident on computer system 1. One continuously running program is the holding tank maintenance program that at step 305 determines whether the holding tank 7 is full of water. If not, diversion valve 6 is activated at step 306 to fill holding tank 7 with water up to its maximum level. Once holding tank 7 is full, processing proceeds to step 307 where diversion valve 6 is switched to its normal position to supply water to the domestic plumbing. At step 304 the structure defensive sequence is activated and the fluid recovery valve 8 is switched to recycle the water from the roof and walls of the structure R into the holding tank 7. At step 308 the water pump 4 is activated to provide a pressure boost above that level of pressure supplied by a residential water pump to pressurize pressure tank 9. At step 309 another continuous loop program is illustrated wherein it is determined whether the pressure tank 9 is fully pressurized. This continuous loop consisting of steps 309 and 308 operate to cycle the water pump 4 to maintain a minimum pressure in the pressure tank 9 in order to provide water to all of the sprinklers 11 at the required pressure.
There are a significant number of philosophical approaches to defending the structure R illustrated in FIGS. 1 and 2 from the impending wildfire. The philosophy illustrated herein is to immediately and at all times provide the maximum protection possible for the structure R itself with the sector defenses being activated concurrently therewith in an ordered sequence. It is possible to activate the sector defenses initially and to subsequently, upon the closer arrival of the impending fire, activate the structure defenses. This is arguably a more risky strategy but is philosophically within the purview of this apparatus and is left up to the structure owner to select the particular defensive sequence that is most applicable to the site-specific factors surrounding the structure.
Initial Fire Deterrent Measures
For the sake of illustration, assume that a wildfire W is approaching sector D as illustrated by the arrow on FIG. 1. At step 310, the initial sprinkling sequence is activated. At step 311 a timing cycle is provided to ensure that the structure R is sprinkled by the plurality of sprinklers 15-17 on or about the structure for a predetermined time interval. This predetermined time interval is a function of the types of materials which are used to build the structure R and the amount of water within holding tank 7 that can be allocated for an initial sprinkling sequence. These are preset parameters that are typically programmed into the system by the owner of the structure R. The various sprinkling systems 15-17 are typically activated in segments to reduce the required volumetric flow required of water pump 5. The sequencing of the sprinkler lines is also performed on a priority basis with, for example, the roof being sprinkled prior to the walls.
While the sprinkling sequence is activated and operational, at step 312 the environmental dependent deterrent measure section of the computer program is activated and at step 313 a fire movement subroutine is activated which polls the anemometer 10 and sensor 2 to determine the locus and velocity of the fire as well as the ambient wind conditions to calculate at step 314 the estimated time of arrival of the fire at the defensive perimeter. This calculation also includes retrieving at step 315 from memory in computer system 1 the definition of the plurality of sectors A-I therefrom to map the fire movement onto sector specific locations in order to identify at step 316 the sectors D which are most likely to be the initial contact with the approaching wildfire. Using the sector specific estimated time of arrival computation, and the water availability data retrieved at step 317, the system determines at step 318 a timed sprinkling sequence which can be weighted on a sector specific basis. A preferred operational sequence is to lightly spray all the vegetation using sprinklers 11, A distributed in the peripheral defensive sectors in order to lightly dampen these combustible materials. At step 317, the level of water in the holding tank 7 was measured and a calculation made as to the availability of water that can be used for supplemental flow in the sectors A, D, G nearest the approaching fire. If sufficient water is available to periodically sprinkle the structure R as well as continue vegetation sprinkling in at least one of the outlying sectors, the sprinklers 11, 14 in the sector D nearest the approaching fire W are activated at step 319 in order to further soak the vegetation in that sector D. Again, as a function of the quantity of water available in holding tank 7, adjacent sectors A, G may also have sprinklers 11, 14 activated therein, possibly at a lower flow level (step 320) than the sector D closest to the approaching wildfire W. An example is to sprinkle for five minutes on with a five minute interval between sprinkler initiations. Once the sprinkling cycles have been activated, the computer system 1 continually monitors the distance away from the structure and the velocity of approach of the fire W.
Fire Within Defensive Perimeter
If any of the local heat sensors 12 are triggered at step 321, indicating the presence of a fire within one of the sectors A-I, the computer program immediately activates sprinklers 11, 14 adjacent to the triggered remote sensors 12 in order to extinguish these localized fires. It is typical in a wildfire situation to have airborne embers ignite vegetation in a condition that is called spotting wherein the embers begin localized fires that, if extinguished at an early stage, do not pose a significant threat to the structure R. Therefore, computer program 1 at step 322 maximizes operational flows of water from water source 5 into holding tank 7 and through recovery valve 8 into holding tank 7. The operational pressure of the water in the lines to sprinklers 11, 14 are maximized by typically interspersing the activation of various sprinkler lines in order to minimize the flow demand on the water supply system. A typical system can not drive all sprinkler heads 11, 14-17 concurrently but can cycle various patterns of sprinkler heads on a time shared basis. Sets of sprinkler heads 11, 14 are plumbed together on a sector by sector basis and may also be orchestrated as a function of the type of vegetation to be sprayed. One set of sprinklers 14 can be used to spray trees and shrubs while another set of sprinklers 11 can be used to spray grassy areas and a third set of sprinklers 15, 16, 17 can be used to spray outlying structures or the main structure 17 itself.
Fire Passing Defensive Perimeter
As the fire approaches the structure R, the computer program, using the input from the ultraviolet sensor 2 as well as from the remote sensors 12, determines when the fire has ceased to approach the structure R. At step 323 the computer program determines whether the wildfire W is passing away from the defensive perimeter and de-escalates the fire activity at step 324 as a function of the nearness of approach and departure of the fire danger. Even though the fire may have ceased approaching, as long as it is within a predetermined distance from the structure it represents a threat to the structure R due to the feature of spotting or potential shifts in wind direction. Therefore, even though the fire may be retreating from the structure R, the computer system 1 continues a periodic wetting of the structure R and the surrounding vegetation in a reasonable cycle as a function of the amount of water available in holding tank 7. The frequency of sprinkling can be decreased at step 325 if the holding tank 7 is unable to maintain a significant quantity of water therein and also as a function changes in the wind magnitude and velocity and the nearness of the fire. When sensor 2 no longer senses the presence of a fire at step 326, the program advances to step 327 where holding tank 7 is refilled and all sprinkling is deactivated. Once the holding tank 7 is filled, the system returns to its prefire state.
In the manner outlined above, it can be seen that the system of the present invention provides an intelligent method of fire prevention by detecting the presence of a fire before it becomes an immediate threat to the structure and proactively applying defensive measures thereto. This minimizes the susceptibility of the structure's flammable materials and the surrounding vegetation to ignition by the wildfire. All prior art systems extinguish fires once they occur but do nothing to prevent the initiation of the fire. Therefore, these prior art firefighting methods are ineffectual in a wildfire environment since the intensity of the wildfire immediately overwhelms any defensive measure that can be installed on a structure given the typical conditions in the wildland/urban interface. In fact, once a wildfire ignites a structure in the wildland/urban interface it is generally impossible to extinguish the blaze in most wildfire conditions since the intensity of the fire thwarts reasonable firefighting activity unless a significant volume of water is available and a number of pieces of firefighting equipment are present before the fire has completely engulfed the structure.
While a specific embodiment of this invention has been disclosed, it is expected that those skilled in the art can and will design alternate embodiments of this invention that fall within the scope of the appended claims.
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The fire deterrent system operates in a preemptive manner by detecting the impending approach of a wildfire within the vicinity of the structure to be protected. The system includes apparatus to identify the locus and direction of spread of a fire while it is outside of a defensive perimeter that encircles the structure and extends outward therefrom. The estimated time of arrival of the fire at the defensive perimeter is determined and the structure and surrounding vegetation sprayed a predetermined time in advance of the determined arrival of the fire. Prewetting the structure and surrounding vegetation reduces the probability of local fires caused by wind-borne embers and reduces the combustibility of these materials to assist conventional fire fighting efforts.
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FIELD OF THE INVENTION
This invention relates generally to bottle packs which separate bottles placed vertically in a container, and guard them from injurious contact with each other.
BRIEF DESCRIPTION OF THE PRIOR ART
There are a great variety of methods and products in common use for holding separate from each other bottles placed vertically in a container, some of which hold the bottles at their tops and bottoms, while others, such as the bottle packs, provide a separating panel or panels inserted between the rows, said panels having ribs or other projections or configurations appropriately spaced to separate the individual bottles in a row from each other. Some bottle packs, or cushion separators as they are sometimes called, present a single face to one row of bottles, while others may be folded, to present two faces, for insertion between two rows of bottles already placed in the container.
BRIEF SUMMARY OF THE INVENTION
It is the object of this invention to create a new and unique type of bottle packs which may be inserted, in a first stage, either manually or mechanically, into a container in advance of placing the bottles there, with the separating panels of said bottle packs then standing vertically upright in folded pairs, and properly located for inserting said bottles in a second stage, also either manually or mechanically, into their predetermined positions, standing vertically and separated from each other by said folding pairs of vertical panels of said bottle packs. These new types of bottle packs, or multiple bottle packs, have each of said pairs of vertical panels serving as a protective barrier between two rows of bottles, each panel of said vertical pairs of panels having one or more outwardly projecting ribs or other configurations, whereby to separate the individual bottles in each row of bottles. Bottom panels are each connected at an edge or edges to the bottom edge of at least one of said vertical panels in such manner as to maintain said vertical panels in a vertical position when said bottom panels are seated horizontally on the bottom wall of said container, the perimeter dimensions of said bottom panels being such as to fit closely within the sidewalls of said container, whereby to maintain said vertical panels in their predetermined locations within said container.
Said bottom panels, reinforced by their connection to said vertical panels, may also serve as a partial support for the bottles, whereby to enhance the carrying capacity of said bottom wall of said container.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which illustrate some preferred embodiments of the invention, FIG. 1 is a cross-section at line AA of FIG. 2 through a stand up folding bottle pack 103, shown in the partially folded condition in which it can be made in a pulp moulding line equipped with a hot press dry finishing system.
FIG. 2 is a plan view of said bottle pack 103 in said partially folded condition.
FIG. 3 is an end view of said bottle pack 103 in the completely folded stand up condition with two rows of bottles in place on the bottom panels of said bottle pack 103.
FIG. 4 is a plan view of said bottle pack 103, in said completely folded stand up condition with two rows of three bottles each in place on the bottom panels of said bottle pack 103.
FIG. 5 is a cross-section at line AA of FIG. 6 through a multiple folding bottle pack type 104 shown in the partially folded condition in which it can be formed.
FIG. 6 is a plan view of said multiple folding bottle pack in said partially folded condition.
FIG. 7 is an end view of said bottle pack 104 in the completely folded stand up condition with three rows of bottles in place on the bottom panels thereof.
FIG. 8 is a plan view of said bottle pack 104, in a completely folded and alone condition with three rows of three each bottles in place on said bottom panels of said bottle pack 104.
FIG. 9 is a cross-section through line AA of FIG. 10 of folding bottle pack 100 in a completely unfolded condition suitable for placing on the flat tray of a dryer tunnel, and for stacking in the same unfolded condition, said folding bottle pack 100 being suitable for separating two rows of three bottles each in a container.
FIG. 10 is a plan view of the completely unfolded bottle pack 100 of FIG. 9.
FIG. 11 is an end view of said bottle pack 100 in the completely folded stand up condition with two rows of bottles in place on the bottom panels of said bottle pack 100.
FIG. 12 is a plan view of the bottle pack 100 completely folded in the stand up condition as in a container, and with the two rows of three bottles each in place.
FIG. 13 is a cross-section at line AA of FIG. 14 through a multiple folding bottle pack 101 for separating from each other the bottles in three rows of bottles with at least two bottles in each row, shown in the completely unfolded condition in which it can be placed on the flat tray of a tunnel dryer.
FIG. 14 is a plan view of the bottle pack 101 in the completely unfolded condition of FIG. 13.
FIG. 15 is an end view of said bottle pack 101 shown in the completely folded stand up position with three rows of bottles in place on said bottom panels of said bottle pack.
FIG. 16 is a plan view of said bottle pack 101, shown in the completely folded stand up condition, with the three rows of three bottles each in place on said bottom panels of said bottle pack 101.
FIG. 17 is a cross-section at line BB of FIG. 2 through the bottle pack 103, showing a locking device in place.
FIG. 18 is an enlarged detail of the locking device shown in FIG. 17.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the drawings, FIG. 1 shows a cross-section, taken at line AA in FIG. 2, of a stand alone folding bottle pack 103, shown in a partly folded condition as manufactured, to separate from each other the individual bottles 17 in two rows of bottles with three bottles in each row, said bottle pack 103 being comprised of:
two vertical panels 33 hingedly connected to each other at their top edges, each of said vertical panels 33 having two outwardly directed ribs 32 stretching in parallel from the bottom edge of said vertical panel 103 towards the top edge of said panel;
two horizontal bottom panels 30, each rigidly connected at an edge to the bottom edge of one of said vertical panels 33 at an angle of 90°, and to the bottom edges of the related two ribs 32, the maintenance of the 90° angle being reinforced by the connection of said two ribs 32 to said bottom panel 30.
FIG. 2 shows a plan of said bottle pack 103 in the partly folded condition of FIG. 1, showing the location of the two elements 15 and 16 of the optional locking device of FIG. 16, located at each end of said vertical panels 33, and the location of said ribs 32, spaced apart from each other and from each end of said bottle pack 103 at predetermined intervals and connected to said bottom panels 30.
FIG. 3 is an end view of said bottle pack 103 of FIG. 1 with said vertical panels 33 folded together in contact with each other to form a protective barrier between the two rows of bottles 17, locked together with the locking elements 15 and 16, and with the bottom panels 33 in a horizontal position whereby to support the two rows of bottles 17 and to maintain said vertical panels 33 in the required stand up vertical position.
FIG. 4 is a plan view of said bottle pack 103 with the two rows of bottles 17 in place on said bottom panels 30 and spaced apart by said vertical panels 33 with the bottles 17 in each row spaced apart from each other by said ribs 32, with said lock elements 15 and 16 of the locking device of FIG. 18, both projecting from one side of said pair of panels 33, and the perimeter dimensions of the two bottom panels together being of appropriate size to fit within the side walls 34 of the container in which they are to be placed.
FIG. 5 is a cross-section taken at line AA of FIG. 6 of a multiple stand alone bottle pack 104, shown in the partly folded condition as manufactured, to separate from each other the individual bottles 17 in three rows of said bottles with three bottles in each row, said bottle pack 104 being comprised of:
four vertical panels 33 hingedly connected to each other in pairs at their respective top edges, each of said vertical panels 33 having two outwardly directed ribs 32 stretching vertically in parallel from the bottom edge of said vertical panel 33 towards the top edge of said panel;
two horizontal bottom panels 30, the first of said bottom panels 30 being rigidly connected at an edge to the bottom edge of the vertical panel 33 facing the first row of bottles 17 in the pack to form an angle of 90° between said first bottom panel 30 and said vertical panel 33, and the second of said bottom panels 30 being rigidly connected at an edge to the bottom edge of the vertical panel 33 facing the third row of said bottles 17 in the pack to form an angle of 90° between said second bottle pack 30 and said vertical panel 33;
two horizontal bottom panels 30x hingedly connected to each other at their respective first edges, and each of said bottom panels 30x being rigidly connected to the bottom edge of one of said vertical panels 33 facing said intermediate row of bottles 17;
each of said bottom panels 30 and 30x being rigidly connected to the bottom edges of the ribs 32 of the vertical panels 33 to which they are also connected.
FIG. 6 is a plan view of the bottle pack 104 of FIG. 5 showing the four of said vertical panels 33 connected together in pairs at their top edges, the two bottom panels 30x connected together in a pair at their first edges, and the two bottom panels 30, two bottom panels 30x and the four vertical panels 33 being connected together in a continuously connected series, each of said bottom panels 30 and 30x being rigidly connected also to each of the two ribs 32 on the particular vertical panel 33 to which they are also connected; the elements 15 and 16 of the four locking devices being shown in their respective locations at each end of each vertical panel.
FIG. 7 is an end view of the bottle pack 104 of FIG. 5, showing each pair of said vertical panels 33 forming a barrier between two rows of bottles 17, said bottles resting on said horizontal bottom panels 30 and 30x, with the elements 15 and 16 of each locking device projecting from one side of each of said pairs of vertical panels 33, and with said bottom panels 30 and 30x in a horizontal position whereby to maintain said vertical panels 33 in an upright position. FIG. 8 is a plan view of the multiple bottle pack 104 of FIG. 7 with the three rows of bottles 17 in place on said bottom panels 30 and 30x, with each pair of vertical panels 33 serving as a barrier between two rows of bottles 17, and the bottles in each row spaced apart by said ribs 32, the lock elements 15 and 16 both projecting from one side of each pair of panels 33.
FIG. 9 is a cross-section, taken at line AA of FIG. 10 of a stand alone bottle pack 100, shown in the fully extended position in which it can be manufactured in a pulp moulding line using a tunnel dryer, to separate from each other the individual bottles 17 in two rows of three bottles each, said bottle pack being comprised of:
two vertical panels 13 hingedly connected to each other at their top edges, each of said vertical panels 13 having two outwardly directed ribs 12 stretching in parallel from the bottom edge of said vertical panel 13 towards the top edge of said panel, each of said ribs 12 having a bottom wall directed outwardly and upwardly from the bottom edge of said vertical panel 13, at an angle of 45° from the vertical face of said vertical panel 13;
two horizontal bottom panels 10, each hingedly connected at an edge to the bottom edge of one of said vertical panels 13, each of said bottom panels 10 having two upwardly directed conical projections 11, each of said conical projections 11 having a wall stretching upwardly and outwardly from said hingedly connected edge at an angle of 45° from the upper surface of said bottom panel 10, and located thereon to make full contact with the facing bottom wall of the immediately adjacent rib 12, each mating pair of the bottom wall of a rib 12 and the facing wall of a conical projection 11 being fitted with the elements 15 and 16 of the locking device of FIG. 18 to lock them together and thus to maintain each vertical panel at an angle of 90° with the bottom panel to which it is hingedly connected.
FIG. 10 is a plan view of the stand alone bottle pack 100 of FIG. 8 in the fully extended position of FIG. 9, showing the two vertical panels connected together in a pair at their top edges, and the two bottom panels 10 each connected to the bottom edge of one of the two vertical panels 13, with the bottom walls of the ribs 12 of said vertical panels 13 each immediately adjacent to a mating wall of one of the conical projections 11, and each mating pair of said walls being provided with the mating elements 15 and 16 of the locking device of FIG. 18.
FIG. 11 is an end view of the bottle pack 100 of FIG. 9, showing the bottles 17 in place on the bottom panels 10, the pair of vertical panels 13 serving as a barrier between the two rows of bottles, and the locking elements 15 and 16 locking together the mating walls of said ribs 12 and said conical projections 11 whereby to maintain said vertical panels 13 in the required angle of 90° to said bottom panels.
FIG. 12 is a plan view of the bottle pack 100 of FIG. 11, showing said bottles 17 in place on said bottom panels 10, with the two rows of bottles 17 separated by the pair of said vertical panels 13, and spaced apart in the rows by the ribs 12 and the conical projections 11, the overall perimeter of the pair of said bottom panels being of appropriate dimensions to fit closely within the interior of the side walls 34 of the container, and thus to maintain said vertical panels in the intended upright position.
FIG. 13 is a cross-section at line AA of FIG. 14, showing a multiple stand alone folding bottle pack 101 in the fully extended condition in which it can be manufactured, to separate from each other the individual bottles 17 in three rows of said bottles with three bottles in each row, said bottle pack being composed of:
four vertical panels 13 hingedly connected to each other in pairs at their top edges, each of said panels 13 having two outwardly directed ribs 12 stretching vertically and in parallel from the bottom edge towards to the top edge of said vertical panel 13, each of said ribs 12 having a bottom panel stretching outwardly and upwardly from the bottom edge of said vertical panel 13 at an angle of 45° with the surface of said vertical panel 13;
two horizontal bottom panels 10, the first of said panels 10 being hingedly connected at one edge with the bottom edge of the vertical panel 13 facing the first row of bottles in the pack, and the second of said bottom panels 10 being hingedly connected with the vertical panel 13 facing the third row of bottles in the pack, each of said bottom panels 10 having two upwardly directed conical projections 11, each of said conical projections having a wall stretching upwardly and outwardly from said hingedly connected edge to form an angle of 45° with the surface of said bottom panel 10;
one bottom panel 10x hingedly connected at each of two parallel edges to the bottom edge of one of said vertical panels 13 facing the second, or intermediate, row of bottles in the pack, said bottom panel 10x having four upwardly directed conical projections, a first two of said conical projections stretching from one of said hingedly connected edges, and the second two of said conical projections 11 stretching from a second parallel edge of said bottom panel 10x, each of said four conical projections 11 having an outwardly and upwardly directed wall stretching from one of said hingedly connected edges of said bottom panel to form an angle of 45° with the surface of said bottom panel 10x;
each mating pair of the bottom wall of a rib 12 and the facing wall of a conical projection 11 being fitted with the elements 15 and 16 of the locking device of FIG. 18, to lock them together and thus to maintain each vertical panel 13 at an angle of 90° with the bottom panel to which it is hingedly connected.
FIG. 14 is a plan view of the stand alone folding bottle pack 101 of FIG. 13 showing the continuously hingedly connected series of bottom panels 10 and 10x and the vertical panels 13 in pairs, with the mating walls of the ribs 12 and the conical projections, and the locking elements 15 and 16 located thereon.
FIG. 15 is an end view of the bottle pack 101 of FIG. 13, showing the three rows of bottles 17 standing on the bottom panels 10 and 10x and the locking elements 15 and 16 locking together the mating walls of the ribs 12 on the vertical panels 13, and the conical projections 11 on the bottom panels 10 and 10x.
FIG. 16 is a plan view of said bottle pack 101 with the three rows of bottles in place on the bottom panels 10 and 10x, said four vertical panels 13 in two pairs serving to separate the three rows of bottles 17 from each other, and said ribs 12 serving to separate from each other the individual bottles 17 in each row, the overall perimeter of the three bottom panels having appropriate dimensions to fit closely with the side walls 34 of the container and thus to maintain said pairs of vertical panels 13 to remain in contact or close proximity with each other and thus to maintain their vertical position as determined by the locked together ribs 12 and conical projections 11.
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A stand alone folding bottle pack to separate and protect from injurious contact with each other the individual bottles in at least two rows of bottles standing vertically in a container, said bottle pack being manufactured in a partially or fully unfolded condition to facilitate moulding and unmoulding and stacking for packaging prior to use, and then optionally locked in the folded stand alone condition, for manual or mechanical insertion into said container, appropriately located and standing erect, ready to receive said bottles, which may then also be inserted either manually or mechanically.
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RELATED APPLICATIONS
This claims priority of U.S. provisional patent application No. 60/837,471 filed Aug. 14, 2006 and entitled “Methods and Apparatus for Analyzing Fluid Properties of Emulsions Using Fluorescence Spectroscopy.”
FIELD
This invention relates to sample analysis by fluorescence spectroscopy.
BACKGROUND
The study of hydrocarbon fluorescence for the purpose of downhole formation fluid evaluation using a wireline logging tool has been proposed in numerous patents (e.g. U.S. Pat. Nos. 2,206,922; 2,346,481; 2,334,475; 6,140,637; and 6,268,603, each of which is incorporated by this reference). As described in one or more of the patents identified above, the proposed methods are generally directed to moving a wireline logging tool through a borehole while irradiating the formation. The methods teach detecting fluorescence through an optically transparent material, which is pressed against the borehole wall. However, in order to be useful to any degree, the transparent material must be pressed against the borehole wall with sufficient force to displace the mud cake. Unfortunately, the natural fluorescence of certain shale and hydrocarbon bearing rocks complicates the interpretation of the logs and the methods taught by the prior art have not been widely adopted.
Schlumberger's Modular Formation Dynamics Tester (MDT™) collects multiple samples at any number of stations in a well. Formation fluids are hydraulically isolated from the drilling fluids (and the mud cake) in the well. The formation fluid is drawn into a flow line inside the MDT tool body and analyzed using absorption spectroscopy through a sapphire optical cell. Contamination monitoring tells the operator when to capture a sample. GOR (Gas/Oil Ratio—the ratio of produced gas to produced oil) and compositional information can be determined by the LFA™ tool and CFA™ tool respectively. However, because the number of available sample bottles contained by the MDT is limited, some have proposed a quasi-continuous log of the formation fluids that could be generated without sample collection. Taking a quasi-continuous log without sample collection is generally referred to as “gargling”. Gargling methods are discussed in U.S. Pat. Nos. 6,476,384; 6,465,775; 5,859,430; and 5,939,717, each of which is incorporated by this reference.
SUMMARY
The present disclosure addresses weaknesses of the prior art described above. Specifically, one embodiment provides a method of analyzing fluid properties. The method comprises providing a downhole fluid analysis tool, extracting a fluid from a downhole formation with the downhole fluid analysis tool, flowing the fluid into the downhole fluid analysis tool, and acquiring a fluorescence signal (i.e. any fluorescence data) from the fluid while downhole. In one embodiment, acquiring a fluorescence signal comprises irradiating the fluid through an optical cell and detecting fluorescence. One embodiment of the method further includes moving the downhole fluid analysis tool through a borehole, and performing the extracting, flowing, and acquiring at multiple locations along the borehole.
In one embodiment, the method further comprises identifying fluid compositional gradients in a fluid column by comparing the fluorescence signals at two or more of the multiple locations along the borehole. One method further comprises flowing the fluid back out of the downhole fluid analysis tool and generating a quasi-continuous log of the fluid without collecting samples. In one embodiment, the method further comprises comparing the fluorescence signal to known fluorescence spectra and identifying the fluid based on the comparison of the fluorescence signal of the fluid to the known fluorescence spectra. In one embodiment, the method further comprises comparing the fluorescence signal to known fluorescence spectra while downhole, and identifying the fluid based on the comparison of the fluorescence signal of the fluid to the known fluorescence spectra while downhole. One embodiment further comprises correlating the fluorescence signal and other physical characteristics of the fluid to generate a database. The other physical characteristics may comprise one or more of asphaltene weight fraction, density, viscosity, and C36+.
One embodiment of the method of analyzing fluid properties further comprises correlating the fluorescence signal with other well-logging or logging-while-drilling data. One embodiment further includes identifying relationships between the fluorescence signal and the well-logging or logging-while-drilling data. Another embodiment further comprises correlating the fluorescence signal with other well-logging or logging-while-drilling data and creating models or tables to assist in interpreting the fluorescence signal.
One aspect provides a method of identifying fluid compositional gradients in an oil column. The method comprises moving a fluid analysis tool through a borehole, setting the fluid analysis tool at a desired sampling interval, extracting a fluid from a formation adjacent to the borehole into a flowline in a body of the tool, irradiating the fluid in the flowline through an optical cell inserted in the flowline, and detecting fluorescence. In one embodiment, the method comprises identifying fluid compositional gradients in a fluid column by comparing the fluorescence signals along the sampling interval. Some embodiments further comprise comparing the detected fluorescence to known fluorescence spectra and identifying the fluid based on the comparison of the detected fluorescence to the known fluorescence spectra. According to one embodiment, a distance between the settings on the sampling interval is regular or irregular. In one embodiment, the irradiation is accomplished with UV wavelength light.
One aspect provides a method of analyzing a sample, comprising acquiring fluorescence data from a formation sample while downhole at multiple stations, and analyzing changes in fluorescence at two or more of the multiple stations to determine whether the sample is the same or different at two or more of the multiple locations. One embodiment further comprises measuring color of the formation sample at the multiple stations and relating changes in the fluorescence data to changes in fluid color. One embodiment further comprises using changes in the fluorescence data to determine if there are fluid compartments within a formation. In one embodiment the method further comprises analyzing a structure of the fluorescence data over an extended depth interval and producing an indication of a physical property correlated with fluorescence. In one embodiment the method further comprises correlating the fluorescence data with other well-logging data, identifying relationships between the fluorescence data and other well-logging data, and creating models or rules to assist in interpretation of other downhole logs. In some embodiments, fluorescence data may form a quasi-continuous log. Moreover, the formation sample may contain a water/oil emulsion.
One embodiment provides an apparatus comprising a downhole fluid analysis tool. The downhole fluid analysis tool comprises a fluid extraction module comprising a flowline, an optical cell disposed in the flowline, an irradiation source at the optical cell, and a fluorescence detection unit at the optical cell. One embodiment also includes a fluid color measurement module. In one embodiment, the irradiation source comprises an LED or laser diode capable of producing visible, ultraviolet, and/or infrared light.
One aspect provides a method comprising retrofitting an existing downhole fluid analysis tool with a fluorescence detection unit. The method may include retrofitting the downhole fluid analysis tool with a UV light source.
Some aspects provide method and apparatus for identifying fluid compositional gradients in an oil column using fluorescence spectroscopy, which may or may not contain an emulsion. One method comprises moving a tool through the borehole, setting the tool at the desired sampling interval, extracting a fluid from the formation into the body of the tool, irradiating the fluid in the flowline through an optical cell inserted in the flowline, and detecting the fluorescence. The light source can be visible, ultraviolet or infrared or any combinations of these. These light source(s) can be an LED(s) or laser diode(s). The fluorescence signal is detected at the front surface of the optical cell.
The description below establishes a relationship between a metric extracted from a fluorescence signal or spectrum, such as a band area or a peak height, and a desired property of the oil. Within an oil column, the correlation between the fluorescence and the color of the oil is such that the metric can be used to detect changes in the fluid composition and/or concentration changes within the oil column. Thus, from the variation in the fluorescence signal, one may ascertain whether compositional gradients exist within a sand body, and furthermore identify fluid compartments (in particular, heavy oil columns are often graded due to biodegradation).
Some aspects apply to heavy oils in which a water/oil emulsion has been created due to the water based muds used for drilling. Emulsions effect absorption measurements because water droplets scatter the light, preventing it from reaching the detector. However, one skilled in the art will recognize that fluorescence can be used instead to map compositional and other property changes (for example, fluorescence can be correlated with oil color or other properties or data).
One aspect utilizes this technique to perform quasi-continuous well logging without collecting samples, in order to rapidly detect compositional variations within an oil column. One aspect improves GOR and composition analysis.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate certain embodiments and are a part of the specification.
FIG. 1 shows an MDT instrument in a borehole that may be retrofitted or provided with a fluorescence detector unit (FDU), such as the FDU shown in FIG. 2 .
FIG. 2 shows a schematic of a CFA™ absorption spectrometer and an FDU.
FIG. 3 shows the effect of a water/oil emulsion on the absorption spectra of a heavy oil from a geographic region in the Middle East.
FIG. 4 shows fluorescence spectra for the same heavy oil associated with FIG. 3 with the same water fractions.
FIG. 5 shows the absorption spectra of six Middle Eastern dead oils with different amounts of asphaltene content.
FIG. 6 is a plot of the log of the OD vs. wave number, for the same six oils in FIG. 5 .
FIG. 7 is a plot of the correlation between the AIP (absorption intercept parameter) and the total fluorescence intensity (TFI) for the six oils identified in FIG. 5 .
FIG. 8 plots the correlation between the AIP and the total TFI and the asphaltene wt % for the six different oils identified in FIG. 5 .
FIG. 9 shows absorption spectra for the same six Middle Eastern oils identified in FIG. 5 after addition of a 3% water emulsion.
FIG. 10 compares the fluorescence intensity with (solid lines) and without (dashed lines) a 3% water/oil emulsion for the same six oils in FIG. 9 .
FIG. 11 compares the fluorescence sensitivity as a function of water fraction for different wavelengths, and droplet size distributions.
Throughout the drawings, identical reference numbers indicate similar, but not necessarily identical elements. While the principles described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents and alternatives falling within the scope of the appended claims.
DETAILED DESCRIPTION
Illustrative embodiments and aspects of the invention are described below. 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, that 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.
Reference throughout the specification to “one embodiment,” “an embodiment,” “some embodiments,” “one aspect,” “an aspect,” or “some aspects” means that a particular feature, structure, method, or characteristic described in connection with the embodiment or aspect is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” or “in some embodiments” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, methods, or characteristics may be combined in any suitable manner in one or more embodiments. The words “including” and “having” shall have the same meaning as the word “comprising.”
Moreover, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.
One advantage of Schlumberger's composition fluid analyzer (CFA™) lies in its ability to detect compositional fluid gradients within an oil column. Compositional gradients can occur due to a variety of sources: biodegradation, gravity, thermal and/or diffusion gradients can all contribute. Fluid gradients may also exhibit discontinuities, signaling the presence of compartments in reservoirs that were previously assumed to be homogeneous—a leading cause of production shortfall in the petroleum industry today.
In light oils, compositional gradients are detected primarily by variations in the GOR ratio. In heavy oils, GOR variation is less significant and compositional gradients are detected by differences in the location of the absorption edge (i.e. color). Heavy oil columns are known to be biodegraded due to the fact that heavy oils result from low temperature catagenesis, and the biodegrading bacteria survive well at low temperature. In spite of this known compositional variation, operational difficulties with heavy oil sampling in water based muds precludes proper analysis of the heavy oils in the column.
Problems arise because heavy oils are commonly drilled with water based muds, which form stable water/oil emulsions due to the interfacial activity of resins and asphaltenes. The emulsions have even higher viscosity than the naturally high viscosity of the original heavy oil. To make matters worse, the flow of a heavy oil emulsion through porous media exacerbates the problem due to effective throat plugging by interfacial tension. Consequently, invaded water flows preferentially, and oil entry into fluid analysis or sampling tool is retarded, resulting in longer cleanup times.
Emulsions affect the optical measurements because absorption spectroscopy (Beer-Lambert law) is highly sensitive to the presence of water droplets and particulates in the flow line. The intensity of the scattering scales rapidly with increasing water fraction and is generally wavelength dependent. The negative effect is enhanced in the forward direction, toward the detector. Because color subtraction is important for GOR and composition analysis, emulsions compromise the accuracy of both Schlumberger's LFA™ (Live Fluid Analyzer) and CFA™ measurements. Even for relatively small water fractions, it is difficult to correct for the noise created by the scattering in the absorption spectra.
One aspect described herein uses a correlation between the color of the formations sample or fluids such as crude oil (absorption) and the sample fluid fluorescence. Some aspects, however, may utilize fluorescence data by itself or in combination with other data. Color characteristics of samples such as crude oils are known to those of ordinary skill in the art having the benefit of this disclosure. However, in emulsified heavy oils, light scattering causes deterioration in the S/N (signal-to-noise) so that crude oil color cannot be accurately determined from the absorption spectra. Thus, there is a need for a more reliable technique to characterize fluids and/or detect compositional gradients in emulsified heavy oil columns. Accordingly, one aspect describes a method of using an FDU (for example an FDU of a CFA™ or any comparable optical fluorescence device) to collect a fluorescence signal or fluorescence data downhole. The fluorescence measurements may be made inside the tool on formations fluids, rather than irradiating borehole walls. For example, Schlumberger's MDT tool may be used and/or modified to collect or extract formation sample fluids for fluorescence analysis (and possibly other analysis—such as color analysis).
Crude oil color is due to photon absorption by polycyclic aromatic hydrocarbons (PAHs). An excited PAH may decay back to the ground state either by re-emitting a photon at a longer wavelength (fluorescence) through non-radiative relaxation (thermal vibrations) or by collisional energy transfer (kinetics). Thus, fluorescence is intimately related to absorption, and the fluorescence intensity is found to be correlated with crude oil color. Since the oil color can be used to detect fluid gradients and fluid compartments in heavy oils, fluorescence may alternatively be used to reveal compositional variations or identify or otherwise characterize formation fluids downhole. However, the correlation between fluorescence and oil color is not trivial. For example, an increase in chromophore concentration in oil results in an increase in color but a decrease in fluorescence. That is, increasing the fluorophore concentration of a crude oil decreases fluorescence. This counterintuitive effect is largely due to intermolecular fluorescence quenching interactions mediated by diffusion and aggregation formation.
Generally speaking, detailed composition and/or concentration information cannot be determined from oil color alone, but relative variations in the concentrations of heavy ends (e.g. asphaltenes) produce large changes in the coloration and associated fluorescence. Hence, it is possible in some circumstances to correlate changes in crude oil color (or fluorescence) with changes in composition and/or concentration. It is also possible to compare fluorescence data downhole with fluorescence data of a known sample from laboratory analysis, provided a careful calibration of the instrument is done in the laboratory beforehand.
Even after a downhole fluid analysis or sampling tool is properly positioned in a borehole, it can take up to fifteen hours of pumping to clean a tool sample flowline, perform accurate optical transmission measurements, and acquire a sample. The long time duration precludes all but the most rudimentary evaluation of compositional variation in heavy oil columns drilled with water based muds. However, for DFA (downhole fluid analysis) purposes, often one does not need a sample, just the analysis. Fluorescence requires only an oil film on an analysis optical cell or window. Oil films find their way onto optical cells or windows early in the flowline cleanup stage, making downhole fluorescence measurement and analysis an attractive data measurement.
It is advantageous to collect the fluorescence signal using a front surface geometry for several reasons. Heavy oils are opaque at visible wavelengths and in a front surface geometry and self absorption affects are minimized. Also the comparatively short escape depth of the fluorescent photons in heavy oils ensures that the fluorescence measurement will be less affected by light scattering than the corresponding absorption measurement.
A long wavelength absorption edge for most crude oils results from polycyclic aromatic hydrocarbons (PAH). The coloration is linearly dependent on the concentration of these chromophores in accord with Beers law
A ••log I I o • ∑ i c i 1 ( 1 )
where: A is absorption,
Io the incident light intensity,
I the transmitted light intensity,
ε i is the molar extinction coefficient for component i, and
c i is the concentration of component i and 1 is the pathlength.
In crude oils, quenching rate constants are diffusion limited. The Stern-Volmer equation is obtained from analysis of the excited state decay rate:
I Fo I F - 1 = k Q k Fo [ Q ] ( 2 )
where: k F is the excited state decay rate and the measured fluorescence decay rate,
k Fo is the intrinsic fluorescence decay rate in the absence of quenchers,
[Q] is the quencher concentration, and
k Q is the diffusional quenching rate constant.
Equation 2 shows that, for IFo>>IF (which applies for crude oils), the fluorescence intensity for a concentrated sample is proportional to the quencher concentration. The quenchers are the large PAHs that have red shifted electronic transitions, i.e., the same molecular fractions that give rise to crude oil coloration.
It can be shown that to the zeroth order, both crude oil coloration (Eq. 1) and crude oil fluorescence intensity (Eq. 2) are linearly dependent on large PAH chromophore population. Thus, for solutions of a given crude oil, one can quantitatively relate coloration and fluorescence intensity.
Crude oil quantum yields are higher at UV excitation wavelengths (e.g. 350 nm) than visible wavelengths (e.g. 450 nm). Also, greater differences in the fluorescence spectra of crude oils are observed at shorter excitation wavelengths. In addition, UV photons have a shorter escape depth than visible photons, so fluorescence spectra are less affected by the emulsions. Therefore, one embodiment of the present invention employs one or more UV LED or laser diode sources downhole on a fluid analysis tool (rather than, for example, blue). A UV light source may be retrofitted on a fluid analysis tool or originally presented. Nevertheless, one skilled in the art will readily recognize that any excitation wavelength may be used according to the principles described herein. In view of this, the present invention is not intended to be limited to those embodiments recited herein.
FIG. 1 diagrammatically illustrates one embodiment of a downhole fluid analysis, sampling, and testing tool in a borehole. In the embodiment of FIG. 1 , the tool comprises a packer module 17 and a flowline 18 . The flowline 18 extends through the tool substantially longitudinally to a pumpout module 13 at a first or upper end. A probe module 16 facilitates fluid communication between the adjacent formation and the flowline 18 . A spectroscopy module 15 (and/or an FDU) may be connected in series to the flowline 18 (see FIG. 2 ). Sample chambers 14 may be connected to the flowline 18 and (if included) may receive and store fluid samples from the formation.
FIG. 2 is a schematic diagram of the CFA™ absorption spectrometer 15 and the FDU 20 . The FDU 20 may comprise a light source 22 , and the light source 22 may comprise an LED or laser producing light at, for example a wavelength of approximately 470 nm. The FDU 20 includes one or more fluorescence detectors, such as first and second detectors 24 , 26 . The first and second detectors 24 , 26 may comprise Si photodiodes and may include two long pass optical filters which transmit light above, for example, about 550 nm and 650 nm, respectively. However, it will be understood by those of ordinary skill in the art having the benefit of this disclosure that the principles described herein are not limited to this particular apparatus or the particular wavelengths discussed. There may be any number of different embodiments of the FDU 20 . For example, in another embodiment, multiple light sources with different wavelengths and multiple detectors are possible. The apparatus of FIG. 2 may be implemented with any fluid analysis tool, such as the tool shown in FIG. 1
FIG. 3 shows the effect of a water/oil emulsion on the absorption spectra of a heavy oil from a geographic region in the Middle East. A first line 28 shows clean absorption spectra of heavy oil from a geographic region in the Middle East. Additional lines illustrate absorption spectra with increasing water fractions. The light scattering from water droplets (several microns in diameter) scales with the increasing water fraction. The peaks 30 , 32 etc. at 1725 and 1760 nm are vibrational hydrocarbon molecules. Water has vibrational bands at 1445 and 2000 nm.
FIG. 4 shows fluorescence spectra of the same heavy oil of FIG. 3 with the same water fractions. The first line 34 shows clean fluorescence spectra of heavy oil from a geographic region in the Middle East. Remaining lines show spectra with increasing water fractions. Compared with the absorption spectra shown in FIG. 3 , the fluorescence spectra of FIG. 4 is much less sensitive to the emulsion or water content of a sample.
Fluorescence signals, as illustrated in the present invention, are less sensitive to an emulsion. In one aspect, this insensitivity of fluorescence to emulsions is exploited (in lieu of absorbance) and used to map color gradients in an oil column which reflect compositional changes. These color gradients (i.e., the ones that exist because of composition changes) can in turn be correlated with other physical properties of the oil such as asphaltene content.
FIG. 5 shows the absorption spectra of six Middle Eastern dead oils with different amounts of asphaltene content. From left to right, the asphaltene fraction increases from 3-13%. The vibrational overtone bands are centered at 1725 nm. The location of the electronic absorption edge reflects the population distribution of the aromatic components in the crude oil. Plotting the log of the OD (optical density) vs. wavelength ( FIG. 6 ) shows that the slope of the absorption edge is the same for all six crude oil samples. By fitting the electronic absorption edge with a linear equation of the form:
log OD =log α+β/λ
One can obtain a single number which characterizes the relative color variation across the entire data set. This is referred to as the absorption intercept parameter (AIP).
FIG. 7 is a plot of the correlation between the AIP (absorption) and the total fluorescence intensity (TFI) for the six oils mentioned above. The correlation is:
AIP=− 1.0905 *TFI− 1.0557 R 2 =0.99
Thus, a single parameter (AIP) characterizing the color of the oil correlates strongly with a single parameter characterizing the fluorescence response (TFI). Accordingly, in some embodiments absorption and fluorescence can be used interchangeably as an indicator of relative fluid coloration.
FIG. 8 plots the correlation between the AIP and the total fluorescence intensity (TFI) and the asphaltene wt % for these six different oils. For the AIP the correlation is:
AIP= 0.0682*Asphaltene wt %−2.0957 R 2 =0.97
For the fluorescence the correlation is:
TFI=− 0.0616*Asphaltene wt %+0.9476
R 2 =0.952
Thus both the AIP and FTI are sensitive to compositional variations. It is expected that these correlations will strengthen when the data are restricted to a single basin. It is also expected that these correlations will further improve when the data are restricted to an individual well. Other correlations may be discovered by those of ordinary skill in the art having the benefit of this disclosure with routine experimentation following the principles described herein, such as between the TFI and C36+ weight fraction, the TFI and density, TFI and composition, and the TFI and viscosity.
Fluorescence logs may be acquired either by logging the entire well in a quasi-continuous mode, without collecting samples, or samples could be captured when the operator decides that the fluid has changed composition. For example, an operator may compare the fluorescence logs at stations A and B. If the fluorescence logs are identical, then the tool is moved to a new location C and the test is repeated. On the other hand, if the fluorescence signal has increased or decreased, then the operator may decide whether to capture a sample based on his knowledge of the formation. The operator may cross-correlate the variation in the fluorescence response with other logs to improve the interpretation. Using a calibrated database for a specific basin, the operator may further relate the fluorescence logs to changes in the composition, density, viscosity and other physical properties.
FIG. 9 is an absorption spectra for the same six Middle Eastern oils identified above after addition of a 3% water emulsion. The water droplets (approx. 1 micron size) produce intense scattering, which severely distorts the absorption spectrum and renders the sample opaque with a resulting loss of information content. The scattering background and water peaks cannot be reliably backed out, to reveal the true color of the oil.
FIG. 10 compares the fluorescence intensity with (solid lines) and without (dashed lines) of a 3% w/o emulsion. The fluorescence signal shows some slight increase but which contributes an offset and does not affect the relative fluorescence intensities and leaves the line-shape unchanged. Water does not fluoresce at visible wavelengths, and the fluorescent photons which escape self-absorption also experience less scattering in a front surface geometry. Thus fluorescence can be used to map compositional variations accurately even when emulsions are present. It is therefore possible for those of ordinary skill in the art having the benefit of this disclosure to detect color (and composition), gradients, or other characteristics in an oil column in the presence of emulsions by using fluorescence logs.
FIG. 11 compares the fluorescence sensitivity as a function of water fraction for different wavelengths and droplet size distributions. Large droplets produce less scattering than small ones. Shorter wavelength UV excitation results in less scattering than the blue wavelength radiation.
As mentioned above, Schlumberger's CFA™ has a fluorescence sensor, which may perform fluorescence spectroscopy by measuring light emission in the green and red ranges of the spectrum after excitation with blue light. Fluorescence in this range is related to the concentration of polycyclic aromatic hydrocarbons (PAH's) in the crude oil. Fluorescence was initially introduced to detect phase transitions particularly in gas condensate systems while sampling. When a phase transition occurs in a retrograde condensate fluid, the newly formed liquid phase will concentrate the heaviest components of the original fluid. As was previously mentioned, these heavy components contain the molecular groups that fluoresce. Fluorescence measurements are highly sensitive—even more so than other types of spectroscopy such as absorption spectroscopy—therefore making it possible to detect the slightest changes in the composition of the fluid being assayed.
Based on the above measurement principles and extensive observations from field practices, several features of CFA™ fluorescence emerge:
Fluorescence does not suffer from strong scattering usually caused by mud solids. Mud solids very likely do not have any PAH's Fluorescence measurements in a borehole are less affected by water droplets in water-oil emulsions than corresponding absorption measurements. This feature allows one to identify oil properties even when oil and water emulsions exist. Fluorescence can be used to type different hydrocarbons such as gas (it should be noted that gas is a fluid), condensate, light oil and black oil. In simple words, gases usually have little or no heavy components, hence very little PAH's. Therefore, gas should have very weak fluorescence. Oil typically has more heavy components, hence much more PAH's. Accordingly, oils should have much stronger fluorescence than gases. Fluorescence is highly sensitive. Therefore, it can detect very small oil droplets mixed with water. Moreover, fluorescence will not react on OBM (oil based mud) because OBM typically should not contain any PAH's.
The preceding description has been presented only to illustrate and describe certain embodiments. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.
The embodiments and aspects were chosen and described in order to best explain the principles of the invention and its practical application. The preceding description is intended to enable others skilled in the art to best utilize the principles in various embodiments and aspects and with various modifications as are suited to the particular use contemplated.
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This relates to methods and apparatus for analyzing samples by fluorescence spectroscopy. In one embodiment, the methods and apparatus use a fluorescence detection unit (FDU) of a composition fluid analyzer (CFA™) module to detect variations in fluid properties (gradients) within an oil bearing column. Some embodiments enable efficient downhole fluid analysis in heavy oils where water/oil emulsions are present (water in dispersed phase and oil in the continuous phase). The principles described herein may also be applied when there are fine particles in the oil such as from unconsolidated sands.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a ceramic-metal composite body, and more specifically the invention relates to a turbine rotor and a method of producing the same.
2. Related Art Statement
Since ceramics such as zirconia, silicon nitride and silicon carbide are excellent in mechanical strength, heat resistance and wear resistance, they have attracted attention as high temperature structural materials and wear resistive materials for gas turbine engine parts, engine parts and so on. However, the ceramics are inferior to the metallic materials in terms of shape formability because they are hard and brittle. Further, ceramics have weak resistance against impact forces due to their poor toughness. For this reason, it is difficult to form mechanical parts such as the engine parts only from the ceramic materials, and they are generally used in a composite structural body in which a metallic member is bonded to a ceramic member.
Heretofore, turbine rotors have been known as metal-ceramic composite bodies of this kind. FIG. 6 is a partial sectional view showing an example of such a turbine rotor. In FIG. 6, the turbine rotor is integrally formed by fitting a ceramic shaft 52 integrally formed with a turbine vane wheel 51 made of ceramics into a depression 54 of a metallic member 53. The fitting is ordinarily carried out through press fitting, shrink fitting, or expansion fitting. A fitting shaft 55 for mounting a compressor wheel not shown is provided on an opposite side to the turbine vane wheel side of the metallic member 53.
3. Problems to be solved by the Present Invention
The above-mentioned turbine rotor has been heretofore used in the state that the whole metallic member 53 had the same high hardness or only a part of the outer periphery of the depression-provided portion which was to be brought into contact with a bearing was further hardened. Therefore, the shaft 55 for fitting a compressor wheel had a high hardness.
In actual use, when a compressor wheel 57 fitted to the compressor wheel-fitting shaft portion 55 by means of a thrust bearing 58 and a tightening nut 56 as shown in FIG. 7 is rotated at a high speed, the compressor wheel 57 is elongated in an arrow direction in this figure, that is, outwardly in a radial direction. Consequently, a distance L of the compressor wheel 57 in this figure shortens. Thus, it has been necessary that the fitting shaft 55 was elastically elongated by means of the tightening nut 56 by a shortened amount of the distance L when the compressor wheel 57 was assembled. However, when the hardness of the compressor wheel-fitting shaft 55 is high as in the conventional case, the fitting shaft 55 cannot allow a necessary amount of the elastic deformation. Thus, there exists a defect that the shrink amount cannot be absorbed, and the compressor wheel 57 slackens during use.
SUMMARY OF THE INVENTION
It is an object of the present invention to obviate the above-mentioned problem, and to provide a turbine rotor which can always afford stable performances while a compressor wheel and a fitting shaft thereof do not slacken even under rotation at high speeds.
The turbine rotor according to the present invention is constituted by a turbine vane wheel made of ceramics, a ceramic shaft integrally formed with the vane wheel, and a metallic shaft bonded to the ceramic shaft. The hardness of a part of or the whole part of the compressor wheel-fitting shaft portion of the metallic shaft is smaller than that of a part of the metallic shaft at a location near the turbine vane wheel side apart from the compressor wheel-fitting shaft portion.
The turbine rotor-producing method according to the present invention is directed to a method of producing a turbine rotor constituted by the ceramic turbine vane wheel, a ceramic shaft integrally formed with the vane wheel and a metallic shaft bonded to the ceramic shaft, and is characterized by subjecting a portion of the metallic shaft located on the turbine vane wheel side apart from the compressor wheel-fitting shaft portion to a hardening treatment such as high frequency induction hardening or ion nitriding before or after the metallic shaft is bonded to the ceramic shaft, thereby rendering the hardness of said portion larger than that of the compressor wheel-fitting shaft portion.
Another turbine rotor-producing method according to the present invention is directed to a method of producing a turbine rotor constituted by a ceramic turbine vane wheel, a ceramic shaft integrally formed with the vane wheel and a metallic shaft bonded to the ceramic shaft, and is characterized in that a part of or the whole part of the metallic shaft is constituted by a precipitation hardenable type alloy, the part of the metallic shaft constituted by the precipitation hardenable alloy is hardened through precipitation hardening treatment after the metallic shaft is bonded to the ceramic shaft, and then a part of or the whole part of the compressor wheel-fitting shaft portion of the metallic shaft is softened under reheating to a solution treatment temperature to make the hardness of a part of or the whole part of the compressor wheel-fitting shaft portion smaller than that of a portion of the metallic shaft located on the turbine vane wheel side apart from said part of the compressor wheel-fitting shaft portion.
According to the present invention, since the hardness of a part of or whole part of the compressor wheel-fitting shaft portion of the metallic shaft is made smaller than that of a portion of the metallic shaft located on the turbine vane wheel side, the fitting shaft can be elastically deformed by means of a tightening nut by a shrink amount of the compressor wheel to be caused under rotation at high speeds, when the compressor wheel is attached to the metallic shaft.
In order to constitute the turbine rotor in such a manner, according to the present invention, the metallic member is adjusted to a given hardness, and then before or after the ceramic member and the metallic member are bonded together, a portion of the metallic member on the turbine vane wheel side is hardened by means of the high frequency induction hardening or the like, or alternatively the whole portion of the metallic member is hardened through aging and subsequently a part of or the whole part of the compressor wheel-fitting shaft portion is softened through solution treatment.
The hardness of the compressor wheel-fitting shaft portion is properly in a range of from Hv 250 to Hv 400 in Vicker's hardness. If the hardness is smaller than Hv 250, sufficient strength of the fitting shaft cannot be obtained, while if it is larger than Hv 400, the elastic deformation required in the present invention cannot be acquired.
These and other objects, features, and advantages of the present invention will be well appreciated upon reading of the following description of the invention when taken in conjunction with the attached drawings, understanding that some modifications, variations and changes could be made by the skilled in the art to which the invention pertains without departing from the spirit of the invention or the scope of the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
For better understanding of the invention, reference is made to the attached drawings, wherein:
FIG. 1 is a partial sectional view showing an embodiment of the turbine rotor according to the present invention;
FIG. 2 is a diagram showing a hardness distribution in a radial direction of the embodiment shown in FIG. 1;
FIG. 3 is a partial sectional view showing another embodiment according to the present invention;
FIG. 4 is a diagram showing a hardness distribution in a radial direction of the embodiment shown in FIG. 3;
FIG. 5 is a partial sectional view showing a still another embodiment according to the present invention;
FIG. 6 is a partial sectional view of a conventional turbine rotor; and
FIG. 7 is a schematic diagram showing a state in which a compressor wheel is fitted to a fitting shaft.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments according to the present invention will be explained in more detail with reference to the attached drawings.
EXAMPLE 1
FIG. 1 is a partial sectional view showing an embodiment of the turbine rotor according to the present invention.
First, a ceramic member 1 was made from silicon nitride produced according to a pressureless sintering method. This ceramic member 1 had a vane wheel 1a having a diameter of 60 mm, a shaft portion 1b having a diameter of 10 mm and a projection 1c at its tip end. A round bar of chromium molybdenum steel (JIS SCM 435) was prepared. This bar had undergone oil quenching after having been entirely held at 850° C. for one hour, and then tempered by reheating at 635° C. for one hour.
The round bar was then machined to form a compressor wheel-fitting shaft 4 having a depression-provided portion 2 of an outer diameter of 10 mm at one end and a threaded portion 3 at the other end. This threaded portion had an outer diameter smaller than that of the depression-provided portion. A projection 1c of the ceramic member 1 was press fitted into the depression of the compressor wheel-fitting shaft 4 at 350° C. to obtain a turbine rotor shown in FIG. 1. At that time, the hardness of the fitting shaft 4 was Hv 295.
The outer periphery of the depression-provided portion 2 of the fitting shaft 4 was then subjected to the surface hardening treatment of ion nitriding. This nitriding treatment was carried out in a mixed gas of H 2 :N 2 =3:7 at 530° C. for 10 hours. As shown in FIG. 2, the hardness of the depression portion 2 after the nitriding treatment was Hv 800 at the surface and decreased toward the inner side therefrom. Thereafter, the turbine rotor was finished to obtain the turbine rotor having a final profile shown in FIG. 1.
After a compressor wheel was mounted onto the thus obtained turbine rotor under consideration upon a shrink amount, a rotary test was carried out at a speed of revolution of 150,000 rpm in a combustion gas for 100 hours by using a hot spin tester. As a result, no slackening was observed in the compressor wheel.
EXAMPLE 2
FIG. 3 is a partial sectional view showing another embodiment of the turbine rotor according to the present invention. A ceramic member 11 was prepared from silicon nitride obtained by a pressureless sintering method. This ceramic member 11 had a vane wheel 11a of a diameter of 60 mm and a projection 11b of a diameter of 8 mm. A round bar of a diameter of 10 mm was prepared from nitriding steel (JIS SACM 645). The whole nitriding steel had been held at 900° C. for one hour, quenched in water and tempered. The hardness of this nitriding steel was Hv 293.
Next, after only the outer periphery of the round bar was worked in a profile substantially equal to that of a metallic shaft shown in FIG. 3, portions 17 and 18 of the round bar which were to be contacted with bearing 15 and 16 were subjected to the surface hardening treatment of ion nitriding. This nitriding treatment was carried out by maintaining the round bar at 550° C. in a mixed gas of H 2 :N 2 :1:1 for 20 hours after the portion other than the bearing-contacting portions 17 and 18 was coverd with a mild steel cover. As shown in FIG. 4, the hardness of the hardened portions 17 and 18 after the nitriding treatment was Hv 1,200 at the surface and decreased toward the inner side therefrom.
Consequently, the compressor wheel-fitting shaft 14 which had a depression-provided portion 12 with the above-mentioned hardened portions 17 and 18 at one end of the nitriding-treated round bar and a threaded portion 13 smaller in outer diameter than that of the depression portion at the other end was obtained. The inner diameter of the depression was 7.9 mm at a portion "A" located between the hardened portions and 8.1 mm at the other portion. The projection 11b of the ceramic member 11 was press fitted into the depression 12 of the compressor wheel-fitting shaft 14 at 350° C. to obtain a turbine rotor shown in FIG. 3. At that time, the portion of the compressor wheel-fitting shaft other than the nitriding treatment hardened portions 17 and 18 had a hardness of Hv 293. Then, the turbine rotor having a final profile was obtained by final finishing.
After the compressor wheel was fitted to this turbine rotor under consideration upon a shrink amount, a rotary test was carried out at a speed of revolution of 150,000 rpm in a combustion gas for 100 hours by using a hot spin tester. As a result, no slackening was observed in the compressor wheel.
EXAMPLE 3
FIG. 5 is a partial sectional view showing still another embodiment of the turbine rotor according to the present invention. First, a ceramic member 21 was prepared from silicon nitride obtained by the pressureless sintering method. This ceramic member 21 had a vane wheel 21a of 60 mm in a diameter and a projection 21b of 7.8 mm in diameter. Then, a round bar of solution-treated maraging steel was worked to obtain a metallic member. This metallic member had a depression-provided portion 22 having a depression of an outer diameter of 9.5 mm and an inner diameter of 8.0 mm at from an open end to a depth of 30 mm and an inner diameter of 7.72 mm at a depth from 30 mm to 45 mm at one end and a threaded portion 23 and a compressor fitting portion 24 smaller in outer diameter than that of the depression-provided portion. Thereafter, the projection 21b of the ceramic member 21 was press fitted into the depression of the metallic member at room temperature to obtain a turbine rotor shown in FIG. 5. At that time, the hardness of metallic portion was HRC 33 in Rockwell Hardness.
Next, the whole turbine rotor was age hardened by heating it at 550° C. for 3 hours. The hardness of the age hardened metallic member was HRC 52. Then, only the compressor fitting portion 24 was reheated at 830° C. for 15 minutes to effect solution treatment. The hardness of the solution-treated fitting portion 24 was HRC 32. Thereafter, the final finishing was carried out to obtain a turbine rotor having a final profile shown in FIG. 5.
A compressor wheel was mounted onto this turbine rotor under consideration upon a shrink amount. Then a rotary test was carried out at a speed of revolution of 150,000 rpm for 100 hours in a combustion gas by using a hot spin tester. As a result, no slackening was observed in the compressor wheel.
The present invention is not restricted to the above-mentioned embodiments only, and many modifications and changes are possible. For instance, although silicon nitride was used as the ceramic members in the above-mentioned embodiments, silicon carbide, sialon, etc. may be used depending upon use purpose. In addition, as the metallic materials, nickel chromium molybdenum steel, precipitation hardenable type stainless steel, precipitation hardenable type super alloy, etc. may be used besides nitriding steel, chromium molybdenum steel, and maraging steel. Although the ceramic member was bonded to the metallic shaft through press fitting in the above-mentioned embodiments, bonding may be carried out by other method such as brazing.
EFFECTS OF THE INVENTION
As obvious from the foregoing explanation, according to the turbine rotor and its producing method of the present invention, the hardness of a part or the whole part of the compressor wheel-fitting shaft of the metallic shaft is designed lower as compared with a portion located on the turbine vane wheel side. Thus, the fitting shaft can be elastically elongated by the tightening nut by a shrink amount of the compressor wheel to be caused during a high speed rotation, when the compressor wheel is assembled, so that no slackening is produced between the compressor wheel and the fitting shaft thereof even at a high speed rotation. Accordingly, the turbine rotor which can always exhibit stable performances can be obtained.
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A turbine rotor including a turbine vane wheel made of ceramics, a ceramic shaft formed integrally with the turbine wheel, and a metallic shaft bonded to the ceramic shaft. The hardness of a part of or the whole part of a compressor wheel-fitting shaft portion of the metallic shaft is made smaller than that of a portion of metallic shaft apart from the compressor wheel-fitting shaft, said portion being located on the turbine vane wheel side. Thereby, slackening between the compressor wheel and the fitting shaft is avoided. Methods of producing the turbine rotor are also disclosed.
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FIELD OF INVENTION
[0001] The present invention relates to software copyright protection and licensing system using radio-frequency identification.
BACKGROUND
[0002] Most commercial computer softwares are distributed with licenses. For example, in a retail shop, softwares are distributed in packages that are shrinked-wrapped. A so-called “shrink-wrap” license accompanies each software package. Such software licensing is based on a licensee's trust and honesty to abide by the license agreement, for example, by breaking the shrink-wrap and agreeing to install a copy of the software in only one computer. In a similar manner, a “site” license allows a licensee to install a predetermined number of copies of a software in many computers, for example, at a site or organisation.
[0003] To enable a licensee to install a software package 10 , a product installation key 14 , as shown in FIGS. 1A and 1B , typically consisting of 16 alphanumeric characters, is also included in the software package. To begin installation of the software package, an installation manager prompts a licensee to enter the product installation key 14 . The installation manager then authenticates the software to ensure that the software is genuine before the software is installed into the computer.
[0004] These software product installation keys in the form of alphanumeric characters are visible and, thus, cannot prevent a software from being installed in more than the agreed number of copies. Enforcement of copyright of these softwares depends very much on the licensee's organizations that own these softwares. It is obvious that enforcement of copyright of softwares installed in homes or small businesses is less effective.
[0005] To ensure more effective enforcement of softwares copyright and licensing, attempts have been made to distribute softwares that require dongles. Each dongle is connected to one of the I/O ports of a computer. Such a protected software queries the I/O port to which a dongle is connected at start-up and at predetermined time intervals during its operation. This means a licensee can only run one copy of the software with a dongle supplied with the software. However, this does not prevent a user from making copies of the software in other machines and operating the software therefrom.
[0006] It can thus be seen that there exists a need for another system for protecting the copyright of softwares and ensuring more effective licensing control. The present invention also aims to overcome the disadvantages of the existing prior art.
SUMMARY
[0007] The following presents a simplified summary to provide a basic understanding of the present invention. This summary is not an extensive overview of the invention, and is not intended to identify key features of the invention. Rather, it is to present some of the inventive concepts of this invention in a generalised form as a prelude to the detailed description that is to follow.
[0008] In one embodiment, the present invention provides a software copyright protection and licensing system using radio-frequency identification (RFID). The system comprises: a RFID tag accompanying a software package, said RFID tag contains at least a product installation and licensing key of the software; and a RFID reader in communication with a central processing unit (CPU) of a computer and the RFID tag; wherein during execution of the software into the CPU, the RFID reader interrogates the RFID tag for the software's product installation and licensing key; said system generates an installation signature (ISig tag ) from the product installation and licensing key and allowing execution of the software when the ISig tag tallies with the installation signature (ISig pc ) stored in the CPU when the software was first installed, or denies execution when the installation signatures do not tally.
[0009] In another embodiment, the present invention provides a method of enforcing software copyright and license comprising: supplying a RFID tag with a software package, said RFID tag containing at least a product installation and licensing key; communicating a RFID reader with a central processing unit (CPU) of a computer and the RFID tag; allowing installation of the software in the CPU if the product installation key is valid, otherwise denying installation of the software package; during installation of the software, prompting a licensee for licensee information, encrypting the licensee information, sending the encrypted licensee information to the RFID tag and generating an installation signature (ISig) for storage in the CPU; and allowing the software to operate if an installation signature obtained from the RFID tag tallies with the installation signature stored in the CPU, otherwise exiting the software operation.
[0010] In yet another embodiment, the present invention provides a computer product. The computer product comprises: a software package; a RFID tag accompanying the software package, said RFID tag containing at least a product installation and licensing key for installing the software; and an amount of adhesive for attaching the RFID tag onto a casing of a central processing unit (CPU) of a computer in which the software is operable; wherein a RFID reader in communication with the CPU and the RFID tag allows installation of the software if the RFID tag is valid.
[0011] In a further embodiment, the installation signature (ISig) comprises a unique identification and a product identification of the software in addition to the licensee information. Preferably, the licensee information comprises one or more of the following: a license number and licensee's name, address and/or contact numbers.
[0012] In yet a further embodiment, the RFID tag has a line and/or an area of weakness surrounding a miniature component of the RFID tag. Preferably, the miniature component of the RFID tag may be a memory chip, a resistor and/or a capacitor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] This invention will be described by way of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:
[0014] FIG. 1A illustrates a conventional shrink-wrapped software package, while FIG. 1B illustrates a conventional product installation key accompanying the software package;
[0015] FIG. 2A illustrates a software copyright protection system using radio-frequency identification in accordance with an embodiment of the present invention; and FIG. 2B illustrates a computer with a radio-frequency identification reader built onto a mother-board according to another embodiment of the present invention;
[0016] FIG. 3A illustrates components of a product installation and licensing key according to another embodiment of the present invention; and FIG. 3B illustrates an installation manager generating a secure installation signature (ISig) according to another embodiment of the present invention;
[0017] FIG. 4 illustrates an installation process of a software package according to another embodiment of the present invention;
[0018] FIG. 5 illustrates an installation process (B) of a new software package according to another embodiment of the present invention;
[0019] FIG. 6 illustrates a re-installation process (C) of a software package according to another embodiment of the present invention;
[0020] FIG. 7 illustrates an installation signature (ISig) regeneration process (D) according to another embodiment of the present invention;
[0021] FIG. 8 illustrates a licensing control system according to another embodiment of the present invention; and
[0022] FIG. 9 illustrates various applications of the software and licensing system according to yet another embodiment of the present invention.
DETAILED DESCRIPTION
[0023] One or more specific and alternative embodiments of the present invention will now be described with reference to the attached figures. It shall be apparent to one skilled in the art, however, that this invention may be practised without such specific details. Some of the details may not be described at length so as not to obscure the invention. For ease of reference, common reference numerals or series of numerals will be used throughout the figures when referring to the same or similar features common to the figures.
[0024] FIG. 2A shows a software package 100 with a radio-frequency identification (RFID) tag 110 according to an embodiment of the present invention. The RFID tag 110 is schematically made up of a memory chip 118 connected to a resistor 122 , a capacitor 126 and an antenna 130 . In one embodiment, the RFID tag 110 around the memory chip 118 is weakened, for example, by a perforated line. In another embodiment, the backing behind the memory chip 118 is thinner compared to the rest of the RFID tag 110 . In yet another embodiment, a line or area of weakness surrounds the miniature components of the RFID tag such as the memory chip 118 , resistor 122 and/or capacitor 126 . It is also possible to provide a line of weakness across one or more coils of the antenna 130 .
[0025] During manufacture of the software package 100 , the memory chip 118 of the RFID tag 110 is encrypted with a unique product installation and licensing key 114 . Other information such as manufacturing date, recommended retail price, destination market, and so on, may also be encrypted in the memory chip 118 . Further information, such as licensee information, number of available licenses, associated computer device number, may be written into the RFID tag 110 via a RFID reader 158 when the tag 110 is in use. FIG. 3A shows the product installation and licensing key 114 is encoded with at least the following information: unique identification 114 a ; product identification 114 b ; product information 114 c ; and licensee information 114 d.
[0026] After purchasing a software package 100 , a user implicitly agrees to the terms of the license agreement, tears off the shrink-wrap from the package and sticks the RFID tag 110 onto a side of a computer's casing 150 , as shown in FIGS. 2A and 2B . FIG. 2B also illustrates the computer having a mother-board 154 and a RFID reader 158 built on the mother-board 154 . As shown in FIG. 2B , the RFID tag 110 and RFID reader 158 are in close proximity to each other. In an embodiment, the RFID operates at a medium frequency, typically around 13.5 MHz, and the distance between the RFID tag 110 and reader 158 is substantially in a range of from about 2 cm to about 20 cm. Preferably, the plane of the RFID tag 110 is perpendicular to the radio-frequency flux radiating from the RFID reader 158 such that the radio-frequency flux and the antenna 130 are optimally coupled.
[0027] After a licensee (user) has removed the software medium, such as, a compact disc and inserted it into an optical drive, an installation manager in the software package 100 invokes the RFID reader 158 to read the product installation and licensing key 114 from the RFID tag 110 without the licensee having to read and manually enter the product installation and licensing key 114 . As shown in FIG. 3B , the RFID reader 158 decodes the product installation and licensing key 114 . The installation manager then extracts the unique identification 114 a , product identification 114 b and licensee information 114 c , and creates an installation hash or signature (ISig) 116 . The installation hash or signature (ISig) 116 is a secure file stored in the computer and is used to verify the copyright and licensing of the software package 100 ; these verifications will be clearer when the installation and execution of a software package according to the present invention is described in FIG. 4 .
[0028] An advantage of the present copyright protection and licensing system is that the product installation and licensing key 114 is in an electronic form and cannot be visually read. By storing the product installation and licensing key 114 in the memory chip 118 of the RFID tag 110 , the present invention helps to enforce software copyright protection. In addition, users are prevented from installing unauthorised copies of the software in separate machines. Thus, enforcement of software licensing becomes more effective. Further, with the line of weakness and/or the thin backing on the RFID tag 110 , these features help to discourage a licensee from tampering with the RFID tag 110 after it is attached to the casing 150 of a computer's CPU.
[0029] FIG. 4 illustrates an installation process 200 of a software package according to another embodiment of the present invention. As shown in FIG. 4 , the installation process 200 is started by a user initiating, in step 204 , to install the software package 100 into a computer. For example, the user removes the software medium, such as a compact disc and inserts it into an optical drive in the computer. Upon the computer's operating system detecting the installation medium and executing the installation command, an installation manager in the software medium invokes the RFID reader 158 , in step 210 , to scan the RFID tag 110 that is supplied with the software package 100 . A decision is made, in step 214 , whether the RFID tag 110 is present. If the RFID tag 110 is attached to the recommended region on a side of the computer casing 150 and is within interrogation range of the RFID reader 158 , the decision in step 214 is positive, ie. “yes” and the process proceeds to step 220 .
[0030] If the decision in step 214 is “no”, the installation manager issues a message to the user, in step 218 , prompting the user to attach the RFID tag 110 at a recommended position. After elapse of a time interval, the installation manager again requests the RFID reader 158 to interrogate the RFID tag 110 . In another embodiment, the RFID interrogation is repeated for a predetermined period of time, after which, the installation manager exits the installation process. In yet another embodiment, the installation manager prompts the user whether to continue with the installation process; if the user so wishes, the installation manager re-executes process steps 210 and 214 . If not, the installation manager exists the installation process.
[0031] When a RFID tag 110 is detected by the RFID reader 158 , in step 214 , the RFID reader 158 sends out a burst of radio-frequency waves and interrogates the RFID tag in step 220 . Powered by the radio-frequency waves inducting the RFID tag's antenna 130 , the RFID tag 110 responds by encrypting the product installation and licensing key 114 from it memory chip 118 and sends a burst of return radio-frequency waves through the antenna 130 back to the RFID reader 158 . In step 224 , the installation manager requests the RFID reader 158 to decrypt the product installation and licensing key 114 from the RFID tag 110 .
[0032] A decision is then made, in step 230 , whether the product installation and licensing key 114 is successfully transmitted by the RFID tag 110 and decrypted by the RFID reader 158 . If the decision in step 230 is negative, ie. “no”, the installation manager considers the RFID tag to be invalid, and proceeds to step 298 and ends the installation process 200 .
[0033] If the decision in step 230 is positive, ie. “yes”, the installation manager extracts the licensee information 114 d from the product installation and licensing key 114 that was already de-crypted by the RFID reader 158 . A decision is then made, in step 244 , whether the licensee information 114 d exists.
[0034] If the software package 100 is new and the licensee information 114 d does not exist, the installation manager proceeds to step 250 . In step 250 , a new installation process B is started. If the decision in step 244 is positive, the installation manager proceeds to process C. In process C, the software package 100 is reinstalled in step 300 .
[0035] FIG. 5 illustrates a new software installation process B according to another embodiment of the present invention. As shown in FIG. 5 , the new software installation process B starts from step 250 . In step 252 , the installation manager requests the user (licensee) for the licensee information. The licensee information may include the licensee name; address; and telephone, facsimile and/or email contact. As soon as the required licensee information is entered by the licensee, the installation manager proceeds to step 254 .
[0036] In step 254 , the installation manager installs the software package 100 into the licensee's computer. At the end of the installation process, a decision is made, in step 256 , whether the installation is successful. If the decision in step 256 is negative, the installation manager determines, in step 258 , that the installation has failed. As a result, the installation manager executes, in step 278 , an installation roll-back and removes the software components that were installed by the installation manager, before ending the installation process in step 298 .
[0037] If the decision in step 256 is positive, the installation manager proceeds to step 260 . In step 260 , the installation manager sends the licensee information 114 d to the RFID reader 158 for the licensee information 114 d to be updated into the product installation and licensing key 114 . The updated product installation and licensing key 114 is then encrypted, also in step 260 , and transmitted to the RFID tag 110 , in steps 264 and 268 . A decision is then made in step 270 whether the licensee information 114 d is encrypted and transmitted to the RFID tag 110 .
[0038] If the decision in step 270 is negative, the installation manager prompts the licensee, in step 274 , whether to retry encrypting and transmitting the licensee information 114 d to the RFID tag 110 . If the licensee's decision in step 274 is positive, the installation manager repeats process steps 260 , 264 and 268 accordingly. In another embodiment, a number of retry in step 274 is predetermined. If the decision in step 274 is negative, the installation manager performs an installation roll-back in step 278 before ending the installation process in step 298 .
[0039] If the decision in step 270 is positive, the installation manager proceeds to step 280 . In step 280 , the installation manager creates the installation signature (ISig) or hash 116 from the unique identification 114 a , product identification 114 b and licensee information 114 d . The installation signature (ISig) 116 is then stored in the licensee's computer, in step 284 . The installation signature stored in the computer is identified as ISig pc in step 288 . A decision is then made, in step 290 , whether the generation and storage of the installation signature ISig pc 116 is successful.
[0040] If the decision in step 290 is negative, the installation manager prompts the licensee, in step 294 , whether to retry storing the installation signature (ISig pc ) 116 . If the licensee's decision in step 294 is positive, the installation manager re-executes the process steps 284 and 288 accordingly. In another embodiment, a number of retry in step 294 is predetermined. If the decision in step 294 is negative, the installation manager proceeds to step 278 and performs an installation roll-back before ending the installation process in step 298 .
[0041] If the decision in step 290 is positive, the installation is successful. Accordingly, the installation manager proceeds to end the new installation process B in step 298 .
[0042] FIG. 6 illustrates a re-installation process of a software package according to another embodiment of the present invention. As shown in FIG. 6 , the re-installation process C starts from step 300 . In step 302 , the installation manager selects the location of the installation signature (ISig) 116 . By default, the installation signature (ISig pc ) 116 is located in a storage drive, such as a boot drive “C” of a computer. In step 304 , the installation manager retrieves the ISig pc from the storage drive. A check is then made, in step 306 , whether the ISig pc is found in the computer.
[0043] If the decision in step 306 is positive, the installation manager requests the RFID reader 158 to extract the unique identification 114 a , product identification 114 b and licensee information 114 d from the RFID tag 110 . An installation signature (ISig tag ) is then generated from the RFID tag 110 in step 310 . The ISig tag is compared to the ISig pc in step 320 and a decision is made, in step 324 .
[0044] If the result of comparison in step 320 is positive, meaning that the installation signatures from the computer and RFID are identical, the decision in step 324 would also be positive. Accordingly, the installation manager proceeds to complete the installation of the software package 100 , in step 330 , before ending the re-installation process C in step 394 .
[0045] If the result of comparison in step 320 is negative, the installation signatures ISig pc and ISig tag are determined to be invalid in step 324 . As a result, the installation manager ends the installation process in step 394 .
[0046] In another embodiment, when the decision in step 324 is negative, the installation manager prompts the licensee whether to retry the re-installation process. If the licensee so wishes, the installation manager proceeds to step 340 . If not, the installation manager proceeds to end the reinstallation process C in step 394 .
[0047] If the ISig pc is not found in step 306 , the installation manager proceeds to step 340 . In step 340 , the installation manager prompts the licensee whether to request for a new installation signature.
[0048] If the licensee declines, in step 340 , to regenerate a new installation signature, the installation manager proceeds to end the re-installation process C in step 394 . If the licensee wishes to regenerate a new installation signature, the installation manager proceeds to step 350 . In step 350 , process D for re-generating a new installation signature is initiated. Process D will be described under FIG. 7 . A decision is then made, in step 380 , whether the new installation signature is successfully re-generated.
[0049] If the decision in step 380 is positive, the installation manager prompts the licensee, in step 382 , to choose a location to store the new installation signature. Upon the licensee entering a requested location, the installation manager stores the new installation signature (ISig) in the computer in step 384 , and replaces the previous installation signature (ISig pc ) in step 386 . Accordingly, the software re-installation process C continues from step 302 .
[0050] If the decision in step 380 is negative, the installation manager prompts the licensee, in step 390 , whether to re-try executing process D. If the licensee wishes, the installation manager executes step 350 again. If the licensee declines, the installation manager ends the reinstallation process in step 394 .
[0051] FIG. 7 illustrates the installation signature regenerating process D according to another embodiment of the present invention. Reinstallation of a software may be required, for example, after one's computer hard disk clashes. It may also happen when a computer operating system need to be reinstalled, for example, after a virus attack and a copy of the ISig has not been copied on a portable drive. As shown in FIG. 7 , the ISig re-generating process D starts from step 350 . In step 352 , the installation manager checks the network ports for any network connection, and a decision is made, in step 354 , whether a network port is available.
[0052] If none of the network port is connected and the decision in step 354 is negative, the installation manager prompts the licensee, in step 370 , to provide a network connection and the process control then jumps to step 374 . Accordingly, the re-installation process continues through steps 380 and 390 (as shown in FIG. 6 ) and steps 352 and 354 . In another embodiment, as shown in FIG. 7 , the process control jumps to steps 352 and 354 from step 370 .
[0053] If the decision in step 354 is positive, the installation manager proceeds to step 356 . In step 356 , the installation manager extracts the product installation and licensing key 114 from the RFID tag 110 , encrypts the key and sends it to the licensor's server. With the information returned from the licensor's server, the installation manager verifies, in step 360 , the product installation and licensing key 114 retrieved from the RFID tag 110 . A decision is then made, in step 362 , whether the product installation and licensing key 114 from the RFID tag 110 is valid.
[0054] If the decision in step 362 is positive, the installation manager keeps a log, in step 364 , for each attempt in re-generating a new installation signature (ISig). The installation manager then proceeds to generate a new installation signature (ISig), in step 368 , and returns process control, in step 374 , to step 380 shown in FIG. 6 . If the decision in step 362 is negative, the installation manager interrupts the installation signature regeneration process and proceeds to end process D in step 394 .
[0055] FIG. 8 illustrates the licensing control of a software package 100 according to another embodiment of the present invention. The licensing control system 300 executes at regular predetermined intervals, and allows a licensee to continue operating the software package 100 as long as the installation signatures from both the computer and RFID tag 110 match each other. As shown in FIG. 8 , the licensing control system 300 starts from step 800 . In step 810 , the licensing system 300 periodically retrieves the installation signature (ISig pc ) from the computer. At substantially the same time, the licensing system 300 also retrieves the unique identification 114 a , product information 114 b , and licensee information 114 d from the RFID tag 110 in step 820 , and generates the installation signature (ISig tag ) from the RFID tag 110 . In another embodiment, the licensing system 300 retrieves the installation signatures (ISig tag ) directly from the memory 118 of the RFID tag 110 in step 825 , instead of re-processing the ISig from the RFID tag 110 .
[0056] In step 840 , the installation signatures from the computer and RFID tag are compared, and a decision is made, in step 844 , whether the software license is still valid. If the decision in step 844 is positive, the licensing system 300 allows the software package 100 to continue operating. The licensing system 300 periodically repeats its control from step 800 after elapse of a predetermined time interval. In another embodiment, the licensing system periodically ends by executing step 870 after each cyclic licensing loop execution.
[0057] If the decision in step 844 is negative, and the installation signatures (ISig) from the computer and RFID tag 110 do not match (in step 848 ), the licensing control system 300 proceeds to step 850 . In step 850 , the licensing system 300 causes the software to exit, and the licensing system 300 to end in step 870 .
[0058] Whilst this copyright protection system is described with a RFID reader 158 installed on the mother-board 154 , the present invention is not so limited. The RFID reader 158 may be an external device, which is connectable to the CPU, for example, via a USB port or any I/O port with an appropriate port driver. In the later embodiment, transmitting and storing the licensee information as part of the installation and licensing key 114 in the memory chip 118 discourage users from making copies of a software and running the copies in separate machines.
[0059] Where a software package 100 is sold with multiple licenses, or so called site licenses, a number of RFID tags 110 corresponding to the number of licenses is included in the package. Each license number is stored as part of the licensee information 114 d in the installation and licensing key 114 .
[0060] So far, the present invention has been described with respect to users installing and executing licensed copies of software packages. The present invention, therefore, provides protection of software copyrights and ensures more effective licensing control. With the present invention, other areas of application such as software asset and licensing management, as shown in FIG. 9 , as part of an entire enterprise management system is also enabled. In such asset and licensing management, a licensee carries a portable RFID reader, interrogates each RFID tag 110 to extract each software product installation and licensing key 114 and sends the product identification and licensing information to a computer for administrative purposes.
[0061] While specific embodiments have been described and illustrated, it is understood that many changes, modifications, variations and combinations thereof could be made to the present invention without departing from the scope of the invention. For example, the RFID tag 110 may be provided with an area of weakness such that tampering with it would separate the memory chip 118 from the other parts of the tag. This would discourage attempts to circumvent software copyright protection.
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The present invention provides a software copyright protection and licensing system ( 200 ) using RFID. A RFID tag ( 110 ) is supplied with a software package ( 100 ). During installation of the software package in a computer, a RFID reader ( 158 ) interrogates the RFID tag ( 110 ) for a product installation and licensing key ( 114 ). During installation of the software, an installation signature (TSig) is generated and stored in the RFID tag and computer, operation of the software is allowed if the installation signatures tally, otherwise permission is denied. Further, the system ( 200 ) allows reinstallation (process C) of the software and/or re-generation (process D) of a new installation signature under certain situations.
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This is a Continuation of application Ser. No. 08/211,165 filed Jun. 21, 1994, now U.S. Pat. No. 5,585,125, which is the U.S. national stage of PCT International Application No. PCT/JP93/01011 filed Jul. 20, 1993.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to molding and cooling apparatus for pressure resisting bottles of synthetic resin, especially polyethylene terephthalate resin (hearinafter called PET).
BACKGROUND OF THE INVENTION
Recently, among biaxially stretched big PET bottles such as 1.5 litter bottles, so-called big foot type petaloid bottles, which is composed of only bottle body having self-standing function, have been widely used instead of prior bottles, which is composed of bottle body having round bottom portion and base cup attached to the round bottom portion. The bottom portion of the big foot type petaloid bottle has complex structure to enables itself to keep standing and to resist against the inner pressure. It does not require a base cup, so that compared to the prior bottle, it has higher productivity and less scrap problem after use.
The distribution of wall thickness of, for example, a 1.5 litter pressure resisting bottle is such as shown in FIG. 4 that the central part 6 (the range of 40 φ of the undersurface of the bottom portion 3) is thicker than that of the leg portion 3 and the valley portion 5 as shown by the line a, and the thickness thereof is more than 2 mm.
The central part 6 of the bottom 3 is required to be thick, because if it is thinner, it lacks mechanical strength and induces crazing and bottom-breakage because of high temperature and high pressure after substance is filled In the bottle.
Therefore, the bottom part 6 of the bottle should be thicker compared to the rest parts. However, since the bottom part 6 is thicker, the cooling speed thereof by blow mold to a certain point (normally, to the temperature of glass transition point of synthetic resin), so that when blowing time Is short and the center part 6 is not cooled enough, the center part 6 of the bottle projects outwardly, as shown in FIG. 8, after released from the mold.
To prevent deformation of the center part 6, in the past, blowing time is set more than 4 seconds to cool the center part 6 by a blow mold to a certain temperature. The temperature characteristic curve b in FIG. 5 shows a relationship between blow time and temperature of the center part 6, which is measured 7 seconds after a bottle is released from a blow mold. It is clear from this temperature characteristic curve b that to prevent deformation of the center part 6 and to cool it below the glass transition point, blow time of longer than 4 seconds is required.
FIG. 6 shows an variation characteristic of blow time which varies depending on the height H (see FIG. 8) between the bottom edged of the leg portion 4 and the center undersurface of the center part 6. In this FIG. 6, the characterist curve c1 indicates that 1 second of blow time is applied, c2 indicates 2 seconds of blow time, c3 indicates 3 seconds of blow time, c4 Indicates 4 seconds of blow time, c5 indicates 5 seconds of blow time and c6 indicates 7 seconds of blow time. It is known from the experience that the height H of 4. 0 mm or more is acquired, crazing and breakage are prevented. According to FIG. 6, more than 4 seconds of blow time is required.
However, in case more than 4 seconds of blow time is applied, the productivity do not improve.
To increase the productivity, number of ideas such as to improve the cooling capacity of a blow mold or to make the wall of a blow mold thinner, thereby affecting the cooling agent to the mold face of the blow mold. However, still such ideas do not efficiently cool the center part of a bottle, and the cost for equipment will raise.
Therefore, the object of the present invention is to shorten the blow time and improve productivity, and also to improve the mechanical strength of the bottom portion of the bottle.
DESCRIPTION OF THE INVENTION
To satisfy the object of the invention, the structure of the present invention is as follows.
Molding method for pressure resisting bottles of synthetic resin is such that the bottle is blowed in a blow mold for about 2 seconds of blowing time, and within 4 seconds after the bottle is released from the blow mold, the center part of the bottom portion of the bottle is compulsively cooled below about 70° C. within a time of 5.5 seconds to 7.0 seconds.
Another molding method for pressure resisting bottles of synthetic resin comprising a big foot type petaloid bottom is such that the bottle is blow molded with a blowing time of about 1.5 seconds to 3.0 seconds, and within 15 seconds after the bottle is released from the blow mold, the projecting deformation, which is formed after the releasing, of the center part of the bottom portion is forced to the reform jig and is pushed back to the original position at maximum, while the inside the bottle is pressured, and the center part is cooled below about 70° C.
Another molding method for pressure resisting bottles of synthetic resin comprising a big foot type petaloid bottom is such that the bottle is blow molded with a blowing time of about 1.5 seconds to 3.0 seconds, and within 15 seconds after the bottle is released from the blow mold, the center part of the bottom portion is forced to a double-form jig to raise higher the height of the center portion, while the inside the bottle is pressured and the center part is cooled below about 70° C.
A cooling apparatus for pressure resisting bottles of sythetic resin having a big foot type petaloid bottom for cooling the bottom right after the bottle is released from a blow mold comprises: a reform jig comprising a mold face, the projecting height of the center part thereof is almost similar to the height of the center part of a bottom mold of a molding device and the rest portion being similar thereto, a jet mouth for cooling air being formed at the center part of the mold face; a press jig capable of holding the bottle cooperated with the reform jig, thereby pressing the bottom portion to a mold surface of the reform jig; and a cooling nozzle capable of entering inside the bottle, thereby blewing the air upper surface of the bottom portion and giving pressure inside the bottle.
Another cooling apparatus for pressure resisting bottles of sythetic resin having a big foot type petaloid bottom for cooling the bottom right after the bottle is released from a blow mold comprises: a double-form jig comprising a mold face, the projecting height of the center part thereof is almost similar to the height of the center part of a bottom mold of a molding device and the rest portion being similar thereto, a jet mouth for cooling air being formed at the center part of the mold face; a press jig capable of holding the bottle cooperated with the reform jig, thereby pressing the bottom portion to a mold surface of the reform jig; and a cooling nozzle capable of entering inside the bottle, thereby blewing the air upper surface of the bottom portion and giving pressure inside the bottle.
The function of the present invention will be described below.
As shown in FIG. 6, even only 2 seconds of blow time is applied, within 4 seconds after released from a blow mold, the height H of the bottle remains more than 4 mm. Therefore, by cooling a bottle with 2 seconds of blow time, and by compusively and rapidly cooling the bottom thereof within 4 seconds after released from a blow mold, the height H of the center part of the bottom portion of the bottle maintains higher than 4 mm.
By arranging the compulsive rapid cooling of the bottom portion of the bottle as such that the temperature of the ceter part of the bottom portion decreases below 70° C. within 5.5 to 7.0 seconds. deformation of the center part caused by high heat (about 80° C. when measured), which comes out of the surface after 25 to 30 seconds after released from the mold, is prevented and that cooling and hardening of the bottom portion can be completed.
When blow time is 1.5 to 3.0 seconds, the height becomes less than 4 mm within 15 seconds after released from the blow mold, and even after 15 seconds, the height of the bottom portion gradually decreases. This indicates that within 15 seconds after a bottle is released from the blow mold, the center part of the bottom portion can be deformed by an outer force.
According to various experimental tests, it is examined that the center part of the bottom portion of a bottle can be deformed to desired shape by an outer force only when the deformation is applied within 15 seconds after the bottle is released from the mold because of an cooling effect in the atmosphere.
By forcing the center part of the bottom portion of the bottle, which projects outwardly, to a reform jig within 15 seconds after release, the projected center part return to a position of blow molding, the maximum returning position, by repulsive force of the reform jig and then cooled and hardened at the position.
By applying pressure in the bottle while the bottom portion thereof is forced to the reform jig, the rest parts of the bottom portion of the bottle such as leg and valley portions do not deform because the pressure affects force to those portions. The compulsive cooling against the bottom portion may be such that the center part is cooled below 70° C. within the shortest period of time and the cooling time is not necessarily limited to a certain range.
By increasing the height of the bottom portion, the resistant strength of the bottom portion of the bottle can be improved, but when the height is set higher by arranging a blow mold, the extension ratio of the leg portion increases resulting such that formative ability of the bottle decreases and voids are produced.
To avoid such inconveniences, the height of the bottom portion is set a little lower than the final product at a process of blowing in a blow mold, and after releasing the bottle from the mold, the center part is deformed by a double-form jig instead of the reform jig until the center part comes up to the position higher than the previous position formed by the mold, and is cooled and hardened.
In taking such process, a compulsive shape of the bottom portion is smoothly blow molded and the height can be maintained high enough, so that the bottle is resistable against high pressure and the bottom thereof does not induce breakage.
A cooling process according to the cooling apparatus is performed such that a bottle released from a blow mold is attached to a reform jig facing the bottom portion of the bottle to the form surface of the jig, and the mouth portion of the bottle is pushed downward by a press jig, reforming the center part of the bottom portion to the original shape and height,the maximum height, formed in the mold.
While pressing the mouth portion of the bottle by the press jig, the cooling air is provided through cooling nozzle, which cools the upper surface of the bottom portion of the bottle and gives pressure inside of the bottle. At the same time, the cooling air is flowed from the flow mouth of the reform jig, which cools the undersurface of the bottom portion and harden the center part thereof. The center part of the bottom portion returns to the original shape formed in the mold.
When a double-form jig is applied instead of a reform jig, a similar process as described above is used, and the height of the bottom portion is pushed upward by the jig forming thereof higher than the previous.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial elevation view of a preferred embodiment of an apparatus according to the present invention, FIG. 2 shows a sectional view of a double-form jig of the apparatus according to the present invention, FIG. 3 shows a sectional view of a bottom portion of a bottle reformed by a double-form jig shown in FIG. 2, FIG. 4 shows a graph of a distribution of a wall thickness of a bottom portion, FIG. 5 shows a graph of temperature characteristic of a center part of the bottom portion against blow time of a bottle, FIG. 6 shows a graph of a various characteristic of the height according to various blow time after release from the mold, FIG. 7 shows a graph of a breakage ratio of the bottom portion according to reform ratio, FIG. 8 shows a sectional view of a deformation of a bottom portion of a bottle because of shortage of cooling after release from the mold.
PREFERRED EMBODIMENT OF THE INVENTION
Preffered embodiment according to the present invention will be described below referring to the drawings.
FIG. 1 shows a partial elevation view of a cooling apparatus according to the present invention, wherein a shaft 15 is secured standing position to a base block 14, a holder 23 which holdes a mouth portion 7 of a bottle 1 and a handler 24 which holds a body 2 are fixed to the shaft 15, a cooling block 18 positioned below the handler 24 is secured to the base block 14.
On the cooling block 18, there is a reform jig 9 comprising a mold surface 10 which is such that the projecting central portion thereof is arranged almost similar to the form surface of a bottom mold of a blow moulding device and the rest portion of the mold surface 10 is arranged similar thereto. The reform jig 9 is cooled by the cooling water W that flows through a cooling passage 22 provided in the cooling block 18. A passage block 19, forming air cooling passage 21 of the cooling block 18, runs in the center of the reform jig 9 in the downward direction. The upper surface comprising recess 20 for the cooling air A to escape is positioned at the center of the mold surface 10 of the reform jig 9, and the front edge of the air cooling passage 21 is positioned as a jet mouth of the cooling air A.
To an upper portion of the shaft 15, a cooling nozzle 17 is fixed capable of moving upward and downward directions. A press jig 16 is fixed to the cooling nozzle 17. The press jig 16 comprises passages throughwhich the air in the bottle escapes when the jig 16 is air sealed by the mouth portion 7 of the bottle.
The cooling nozzle 17 moves in the downward direction by a cylinder (not shown) and enter in the bottle 1 through the mouth portion 7. The press jig 16 is arranged such that when the bottom edge of the cooling nozzle 17 comes close to the center part 6 of the bottom portion 3, it pushes the upper surface of the mouth portion 7.
The cooling block 18 is capable of moving downwardly and upwardly between the length a little longer than the height of the mold surface 10 of the reform jig 9. The holder 23 and the handler 24 lightly hold the bottle 1 as to prevent the bottle 1 to move, and they enable the bottle 1 to move in the downward and upward directions.
To the preferred embodiment shown in FIG. 1, a bottle 1 which is released from a mold 7 seconds ago is attached, and the bottle is pressed by the press jig 16 with 25 kg/f, and the cooling air A of 6.5 kg/cm 2 is supplied through the cooling nozzle 17 and the cooling passage 21. By keeping the inner pressure of the bottle 6 kg/ cm 2 , the center part 6 of the bottom portion 3 is compulsively cooled for 5.5 seconds, while releasing the cooling air A through two passages of 1.5 mm φ of the press jig 16.
This tests are applied for bottles which have received 1.5 second, 2.0 second, 2.5 second and 3.0 second of air blow. According to the bottles to which compulsive cooling process is applied according to the the present invention, the heights H of the bottom portions of the bottles 1 are all 4.2 mm. On the other hand, according to the bottles to which no cooling process is applied, the heights H are 2.0 mm with 1.5 second blow, 2.3 mm with 2.0 second blow, 2.7 mm with 2.5 second blow and 3.2 mm with 3.0 second blow. All of them are under 4.0 mm.
Tests for examine breakage of the bottom portion of the bottle is also done using bottles blowed for 2.5 seconds of blow time. The bottles being received the compulsive cooling according to the present invention, none out of 20 bottles occured breakage, whereas the bottles not being received the cooling, 18 bottles out 20 occured breakage.
In FIG. 2, the center face 13 of the mold surface 12 of the double-form jig projects higher than the mold surface, which is indicated by a dot line in the FIG. 2, of the bottom mold of the blow molding device. Therefore, the bottom portion 3 of the bottle 1 completed by the double-form jig 11 is such as shown in FIG. 3 that the center part 6 thereof is recessed inwardly compared to the dot line, and that the radius of curve ration of the leg portion 4 toward inside becomes smaller and that of the center part of the valley portion 5 becomes larger.
The reformation of the center part 6 has limitation.
A bottle 1 is blow molded for 2 second of blow time in a blow mold whose height of the bottom mold is 3.9 mm. The bottle, 5 seconds later it is released from the mold, is reformed and cooled in the cooling apparatus 8 shown in FIG. 1 comprising double-form jig 11. When a double-form jig 11 comprising the height of 5 mm, the reform quantity is 1.1 mm, the height thereof is 4.43 mm and the mold ratio is 114%. When the double-form jig 11 with the height of 6 mm is applied, the reform ratio is 2.1 mm, the height thereof is 5.49 mm and the reform ration is 141%. Further, when the double-form jig 11 with the height of 7 mm Is applied, the reform ratio is 3.1 mm, the height thereof is 5.86 mm and the reform ration is 150%. The reform ratio is calculated by the formula: (the height of the reform bottom portion 3/the height of the bottom mold of a blow mold device)×100.
Breakage tests are completed using the reformed bottles mentioned above. When a double-jig 11 comprising the height of 5 mm is applied, one out of 15 bottles produced breakage. For a double-jig 11 comprising the height of 6 mm, 9 out of 15 bottles produced breakage. For a double-jig 11 comprising the height of 7 mm, 12 out of 15 bottles produced breakage.
As shown in FIG. 7, since the allowable breakage ratio for the prior art is 30%, the mold ratio according to the present invention is allowed nearly 130%. As the forming capability of the present biaxial blow molding technic is advanced, the mold ratio accordant to the present invention may be limited below 120%.
THE EFFECTS OF THE INVENTION
The present invention performs the following effects.
The bottom portion of the bottle being biaxially stretch molded is cooled right after it is released from the mold, so that shortage of cooling process by the blow mold is covered and that the blowing time of the blow mold can be shortened and the productivity improves.
The bottom portion of the bottle after blow molding is compulsively cooled after releasing from the mold, so that it is not required to prepare a new blow mold, and that bottles are produced with lower cost in equipment.
With a reform jig or a double-form jig, the height of the bottom portion of the bottle can be maintained high enough, so that bottles with higher resistance against the pressure and outer force can be produced.
The cooling apparatus comprises a reform jig or double-form jig, a press jig and a cooling nozzle, so that the component thereof is simple, and that it performs easy handling and operation.
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A biaxially stretched blow molded bottle of a synthetic resin having a big foot type petaloid bottom is produced in a blow time of not more than 3 seconds, and after the bottle has been released from the mold, the temperature of the bottom portion of the bottom does not rise higher than 70° C., thereby supplementing the capability of the metal mold for cooling the bottom portion. Thus, irregular deformation of the central part of the bottom portion is prevented, molding of the bottom portion with high pressure resisting and mechanical strength is achieved to avoid breakage, and a sufficient height of the central part of the bottom portion is ensured. Additionally, productivity of pressure resisting bottles is improved by reducing the blow time from 4-5 seconds to not more than 3 seconds.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/856,374, filed Aug. 13, 2010, abandoned, which is a continuation of U.S. patent application Ser. No. 10/511,743, filed Apr. 18, 2005, now U.S. Pat. No. 7,776,720, which is a national stage application of International Application No. PCT/EP03/04069, filed Apr. 17, 2003, which claims priority to Irish Patent Application No. S2002/0289, filed Apr. 19, 2002, and to Great Britain Patent Application No. 0225033.0, filed Oct. 28, 2002.
TECHNICAL FIELD
[0002] The invention relates to program-controlled dicing of a substrate, particularly, but not limited to, a semiconductor substrate, using a pulsed laser.
BACKGROUND INFORMATION
[0003] Wafer dicing is a critical aspect of package assembly that facilitates all subsequent operations in an assembly process. Wafer dicing is conventionally achieved by dicing a wafer with a mechanical saw. Use of a mechanical saw has disadvantages such as low yield, chipping and cracking. Thin wafers cannot be machined due to the stresses induced in the wafer by the saw resulting in low die strength. The strength of the dies produced when a semiconductor substrate is diced is an important factor as low die strengths reduce reliability. Improving die strength minimizes breakages and the onset of micro-cracking and improves device reliability.
SUMMARY OF THE DISCLOSURE
[0004] According to a first aspect of the invention, there is provided a method of using a pulsed laser for program-controlled dicing of a substrate comprising at least one layer, the method comprising the steps of: providing program control means and associated data storage means for controlling the pulsed laser, providing in the associated data storage means a laser cutting strategy file of at least one selected combination of pulse rate, pulse energy and pulse spatial overlap of pulses produced by the laser at the substrate to restrict damage to the respective at least one layer while maximizing machining rate for the at least one layer, providing in the laser cutting strategy file data representative of at least one selected plurality of scans of the respective at least one layer by the pulsed laser necessary to cut through the respective at least one layer when the pulsed laser is operating according to the respective at least one combination stored in the laser cutting strategy file; and using the laser under control of the program control means driven by the laser cutting strategy file to scan the at least one layer with the respective at least one selected plurality of scans at least to facilitate dicing of the substrate such that a resultant die has at least a predetermined die strength and a yield of operational die equals at least a predetermined minimum yield.
[0005] Preferably, the steps of providing a laser cutting strategy file comprise, for each of the at least one layer, the steps of varying at least one of a combination of pulse rut; pulse energy, pulse spatial overlap to provide a respective combination; measuring a cutting rate of the respective layer using the respective combination; examining the layer to determine whether damage is restricted to a predetermined extent; dicing the substrate and measuring yield of the resultant die; measuring die strength of the resultant die; creating a laser cutting strategy file of a selected combination which maximizes cutting rate while resulting in a yield of operational die which have at least the predetermined minimum yield and for which the die have at least the predetermined die strength scanning the at least one layer using the selected combination to determine a plurality of scans necessary to cut though the layer; and storing the selected plurality of scans in the laser cutting strategy file.
[0006] Conveniently, the die strength is measured using a Weibull die strength test.
[0007] Advantageously, the step of using the laser to scan the at least one layer includes providing a galvanometer-based scanner.
[0008] Conveniently, the step of using the laser to scan the at least one layer includes providing a telecentric scan lens for scanning a laser beam from the laser across the substrate and the step of providing a laser cutting strategy file comprises the steps of: mapping a laser energy density received in a focal plane of the telecentric scan lens to produce a laser energy density map of a field of view of the telecentric lens using the selected combination of pulse rate, pulse energy and pulse spatial overlap of pulses; storing the laser energy density map as an array in the storage means; and using the laser energy density map to modify, with the control means, at least one of the pulse repetition rate and the pulse energy of the selected combination to produce a constant laser energy density at scanned points in the field of view at the substrate.
[0009] Conveniently, the step of mapping a laser energy density comprises using a laser power meter to measure laser energy density at representative locations within the field of view of the telecentric lens.
[0010] Advantageously, the step of providing a selected combination comprises providing a selected combination which restrict thermal loading of the material of the respective layer to restrict mechanical stress to a predetermined maximum.
[0011] Conveniently, the selected combination is used for less than the selected plurality of scans, which corresponds to the selected combination, to machine a layer to be cut and the layer is scanned for further scans up to the selected plurality using a combination which will not significantly machine an underlying layer such that substantially no machining occurs of the underlying layer should the laser continue to scan the substrate after the layer to be out has been cut through.
[0012] Advantageously, the method comprises scribing a substrate through the layer to be cut for subsequent mechanical dicing of the substrate.
[0013] Conveniently, where the substrate includes an active layer, the step of providing a selected combination to restrict damage to the at least one layer comprises providing a selected combination which does not significantly affect the subsequent operation of active devices in the active layer.
[0014] Advantageously, the step of providing a selected combination which does not significantly affect the subsequent operation of active devices in the active layer comprises providing a combination which does not cause significant cracks to propagate through the active layer.
[0015] Conveniently, the step of providing a selected combination comprises the steps of: providing an initial combination at which the laser machines the substrate at an initial rate which does not cause significant crack propagation due to thermal shock at an ambient temperature, and such tat a temperature of the substrate is raised by the machining after a predetermined plurality of scans of the substrate by the laser to a raised temperature above ambient temperature; and providing a working combination at which the laser machines the substrate at a working rate, higher than the initial rate, which does not cause significant crack propagation due to thermal shock at the raised temperature; and the step of machining the substrate includes: machining an initial depth of the substrate using the initial combination for at least the predetermined plurality of scans; and machining at least part of a remaining depth of the substrate using the working combination.
[0016] Preferably, an energy of at least a first of the plurality of scans is lower than an energy of succeeding scans of the plurality of scans such that a generation of surface micro-cracks is less than would otherwise be produced.
[0017] Advantageously, an energy of at least a final of the plurality of scans is lower than an energy of preceding scans of the plurality of scans such that backside chipping of the substrate is less than would otherwise be produced.
[0018] Advantageously, energy of the plurality of scans is varied between scans to facilitate removal of debris generated during dicing of the substrate, conveniently by increasing laser energy with increasing machining depth to remove debris from a dice lane.
[0019] Advantageously, the method includes the further steps of: providing gas handling means to provide a gaseous environment for the substrate; using the gaseous environment to control a chemical reaction with the substrate at least one of prior to, during and after dicing the substrate to enhance a strength of the resultant die.
[0020] Conveniently, the step of providing gas handling means includes providing gas delivery head means for delivering gas substantially uniformly to a cutting region of the substrate to facilitate substantially uniform cutting of the substrate.
[0021] Advantageously, the step of providing gas handling means comprises providing means to control at least one of flow rate, concentration, temperature, type of gas and a mixture of types of gases.
[0022] Conveniently, the step of providing a gaseous environment comprises providing a passive inert gas environment for substantially preventing oxidation of walls of a die during machining.
[0023] Alternatively, tie step of providing a gaseous environment comprises providing an active gas environment.
[0024] Conveniently, the step of providing an active gas environment comprises etching walls of a die with the active gas to reduce surface toughness of the walls and thereby improve the die strength.
[0025] Advantageously, the step of providing an active gas environment comprises etching walls of a die with the active gas substantially to remove a heat affected zone produced during machining, and thereby improve the die strength.
[0026] Advantageously, the step of providing an active gas environment comprises reducing debris, produced during machining, adhering to surfaces of machined die.
[0027] Conveniently, the method comprises the further step after dicing of scanning an edge of the resultant die with the laser with sufficient energy to heat sidewalls of the resultant die to reduce surface roughness thereof and thereby increase die strength of the resultant die.
[0028] Conveniently, the method is adapted for producing die with rounded corners by scanning the laser beam along a curved trajectory at corners of the die using a galvanometer based scanner, wherein the selected combination is adapted to maintain the selected pulse spatial overlap between consecutive laser pulses around an entire circumference of the die.
[0029] Conveniently, the selected combination is adapted to deliver pulses at an arcuate portion or corner of the die such that substantially no over-cutting or undercutting generating a defect at the arcuate die edge or corner occurs.
[0030] Advantageously, the method is adapted for forming a tapered dice lane having arcuate walls tapering inwards in a direction away from the laser beam by varying a width of the dice lane as the laser scans through the substrate wherein the selected combination is modified to give a finely controlled taper and smooth die sidewalls, and thereby increase die strength of the resultant die.
[0031] Conveniently, the laser is a Q-switched laser device.
[0032] Preferably, a laser beam from the laser is directed by rotatable mirrors.
[0033] Conveniently, the substrate is mounted on a tape and energy of final scans of the laser is controlled substantially to prevent damage to the tape.
[0034] Preferably, the tape is substantially transparent to ultraviolet radiation.
[0035] Advantageously, the tape is polyolefin-based.
[0036] According to a second aspect of the invention, there is provided an apparatus for program-controlled dicing of a substrate comprising at least one layer, the apparatus comprising: a pulsed laser; and program control means and associated data storage means for controlling the pulsed laser using a laser cutting strategy file, stored in the data storage means, of at least one respective selected combination of pulse rate, pulse energy and pulse spatial overlap of pulses produced by the laser at the substrate and data representative of at least one respective selected plurality of scans of the respective at least one layer by the pulsed laser necessary to cut through the respective at least one layer; such that in use a resultant die has at least a predetermined die strength and a yield of operational die equals at least a predetermined minimum yield.
[0037] Preferably, the program control means includes control means for varying at least one of pulse rate, pulse energy and pulse spatial overlap for controlling the laser subject to the at least one respective selected combination.
[0038] Conveniently, the apparatus includes telecentric scan lens means for scanning a laser beam from the laser across the substrate.
[0039] Advantageously, the apparatus includes laser power measuring means for mapping a laser energy density received in a focal plane of the telecentric scan lens to produce a laser energy density map of a field of view of the telecentric lens using the selected combination of pulse rate, pulse energy and pulse spatial overlap of pulse for stowing the laser energy density map as an array in the data storage mean for modifying the at least one respective selected combination to compensate for irregularities, introduced by the telecentric lens, of laser energy density at the substrate.
[0040] Preferably, the apparatus flier comprises gas handling means for providing a gaseous environment for the substrate for controlling a chemical reaction with the substrate at least one of prior to, during and after dicing the substrate to enhance strength of the resultant die.
[0041] Advantageously, the gas handling means includes gas delivery head means for uniformly delivering gas to a cutting region of the substrate.
[0042] Preferably, the gas handling means comprises control means for controlling at least one of flow rate, concentration, temperature, type of gas and a mixture of types of gases.
[0043] Conveniently, the gas handling means is arranged to provide an inert gas environment for substantially preventing oxidation of walls of a die during machining.
[0044] Alternatively, the gas handling means is arranged to provide an active gas environment.
[0045] Advantageously, the gas handling means is arranged to etch walls of a die with the active gas to reduce surface roughness of the walls, and thereby increase die strength.
[0046] Advantageously, the gas handling means is arranged to etch walls of a die with the active gas substantially to remove a heat affected zone produced during machining, and thereby increase die strength.
[0047] Advantageously, the gas handling means is arranged to etch walls of a die with the active gas to reduce debris, produced during machining, adhering to surfaces of machined die.
[0048] Conveniently, the apparatus further comprises a galvanometer-based scanner for producing die with rounded corners by a laser beam along a curved trajectory at corners of the die, wherein the selected combination is arranged to maintain the selected pulse spatial overlap between consecutive laser pulses around an entire circumference of the die.
[0049] Advantageously, the selected combination is arranged to control laser pulse delivery at an arcuate portion or corner of a die edge such that substantially no over-cutting or undercutting occurs which would generate a defect at the die edge.
[0050] Conveniently, the apparatus is arranged for forming a tapered dice lane having arcuate walls tapering inwards in a direction away from the laser beam by varying a width of the dice lane as the laser scans through the substrate wherein the selected combination is modified to give a finely controlled taper with smooth die walls, and thereby increase die strength of the resultant die.
[0051] Preferably, the laser is a Q-switched laser device.
[0052] Conveniently, the apparatus includes rotatable mirrors directing a laser beam from the laser on the substrate.
[0053] Preferably, the apparatus is arranged for a substrate mounted on a tape, wherein the laser is controlled in final scans of the substrate not substantially to damage the tape.
[0054] Conveniently, the tape is substantially transparent to ultraviolet light.
[0055] Advantageously, the tape is polyolefin-based.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:
[0057] FIG. 1 is a plan view of a diced silicon wafer;
[0058] FIG. 2 shows transmitted laser intensity as a percentage of incident laser intensity over a field of view (40 mm×40 mm) of a telecentric scan lens objective for use with the invention and also the variation in laser pulse energy for machining a trench of uniform depth according to the invention;
[0059] FIG. 3( i ) is a vertical cross-section of a multilayered substrate suitable for dicing according to the invention;
[0060] FIG. 3( ii ) represents a four-step laser process used to dice the multilayered substrate in FIG. 3( i ) according to the invention;
[0061] FIGS. 4( i ) to 4 ( iii ) are vertical cross-sections of a multilayered structure in which a pre-scribe trench is machined in a top layer according to the invention;
[0062] FIGS. 5( i ) a and 5 ( i ) b are vertical cross-sections of a semiconductor substrate diced from an active device side according to the invention;
[0063] FIGS. 5( ii ) a to 5 ( ii ) c are vertical cross-sections of a semiconductor substrate diced from a side opposed to the active device side according to the invention;
[0064] FIG. 6 is a graph, helpful in understanding the invention, of relative die strength as abscissa and proportion of die surviving as ordinates for different spatial overlaps of successive laser pulses;
[0065] FIG. 7( i ) shows a plurality of die with rounded corners, produced according to the invention;
[0066] FIG. 7( ii ) shows a plurality of conventionally diced die according to the prior art;
[0067] FIG. 8 is a schematic vertical cross-section of tapered dice lane side walls produced according to the invention;
[0068] FIGS. 9( i ) to 9 ( iii ) are vertical cross-sections of a single layer structure machined, according to the invention; and
[0069] FIG. 10 is a vertical cross-section of a substrate machined according to the invention mounted on a carrier tape.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0070] A laser beam may be used to dice a semiconductor wafer 10 and thereby singulate devices 11 from the wafer by scanning a Q-switched laser beam over the wafer surface using rotating mirrors in a galvanometer type system to form a pattern such as that shown in FIG. 1 . Focusing of the laser beam may be achieved using a telecentric type scan lens.
[0071] In embodiments of this invention, the temporal separation of consecutive laser pulses (Δt) and the laser pulse energy (E) is varied during machining of a single or multilayered substrate in order to reduce thermal loading in different portions of the single layer or in each of the materials in the substrate and the subsequent mechanical stress or damage that results.
[0072] By way of example, a multilayered material workpiece 30 consisting of four layers 31 , 32 , 33 and 34 of three different material types is shown in FIG. 3( i ). These materials could be, for example, a polymer material first layer 31 on a metal second layer 32 on a polymer third layer 33 on a semiconductor substrate 34 . FIG. 3( ii ), which is a plot of time (corresponding to distance machined though the multilayer s) as abscissa and pulse energy as ordinates, illustrates a four step approach to dicing the substrate. In order to machine the first layer 31 in such a way as to reduce thermal loading and consequent mechanical damage in the polymer material laser pulse energy E 1 is low and an inter-pulse separation Δt 1 is high. Polymer materials will melt and be damaged at high laser energies of, for example several hundred microJoules per pulse, but they will be cut cleanly at lower laser pulse energies, for example 10 microJoules per pulse. Also if the repetition rate is too high (i.e. Δt is too low) too much heat will enter the polymer material over too short a time and the polymer will melt and be damaged, so for polymers the repetition rate is kept low (i.e. Δt is high). In general, values of Δt and E are chosen based on known optical and thermal properties of the material or are determined experimentally. The number of laser pulses delivered at Δt 1 and E 1 is determined by the thickness of first layer 31 .
[0073] After machining through the first layer 31 with laser beam 35 , the laser parameters are changed to Δt 2 and E 3 , where chosen values of Δt 2 and E 3 (like Δt and E for all layers in the substrate) are determined by the thermal properties and also the optical absorption properties of the material at the laser wavelength used. After the machining of the second layer 32 , the laser properties are returned to Δt 1 and E 1 to machine the third layer 33 which is of similar material to the first layer 31 . After machining of the third layer 33 , the laser properties are changed to Δt 3 and E 2 to machine the fourth layer 34 . During machining of each layer in the multilayer substrate the pulse energies E 1 , E 2 and E 3 may be varied in a manner to be described across the field of view of the focusing objective in order to compensate for irregularities in the laser energy transmitted by the telecentric lens, to ensure uniformity of machining through each layer of the substrate.
[0074] In practice, prior to machining the layered substrate, a laser cutting strategy file is generated to contain a series of commands to the laser to change Δt and E for each layer and to control a galvanometer scanner for positioning of the laser beam on the workpiece surface. In addition, a respective number of laser scans necessary to cut through each respective layer is pre-programmed in the laser cutting strategy file from a prior knowledge of thicknesses of each of the layers 31 , 32 , 33 , 34 .
[0075] Initially, this data may be collected experimentally, by scanning layers of different materials using different pulse energies and pulse repetition rates and observing any damage, for example melting or crack propagation in the layer. The resultant effect on die strength of different pulse energies and pulse repetition rates may also be determined using, for example, a known Weibull die strength test and a combination selected for each layer which produces die with at least required die strength. In addition, the yield of die may be determined to ensure that the selected combination is not damaging devices on the substrate and thereby adversely affecting the yield. Having selected a combination of pulse energy and pulse repetition rate which causes only acceptable damage and produces die of a required die strength and acceptable yield, the number of scans required to cut though a known thickness of material may then also be determined experimentally. These values may then be used to write, the laser cutting strategy file.
[0076] Dicing in this way leads to superior die strength compared with conventional laser dicing methods.
[0077] In a further embodiment of this invention, the inter-pulse temporal separation Δt and the laser pulse energy E are changed during the machining of a single layer of a multilayered material. Referring to FIGS. 4( i ) to 4 ( iii ), a first layer 41 to be machined with a laser beam 44 overlies a second layer 42 on a substrate 43 . As the first layer 41 is machined, the pulse properties Δt and E of the laser beam 44 are changed just prior to completion of machining trough the first layer 41 , as illustrated by the changed broken line representing the changed laser beam 441 , during machining of the first layer 41 in order to prevent damage to an underlying second layer 42 . In general, damage to the underlying layer 42 is prevented by reducing the pulse energy E to below a melting threshold of the material constituting the underlying layer. A trench 45 machined in layer 41 of FIG. 4 can be used as a pre-mechanical scribing trench. In this case die strength is improved compared with the prior art as, by appropriate choices of laser pulse energy and pulse repetition rate, there is no cracking in the top layer 41 or in the underlying layer 42 that could grow during a mechanical scribe and break process performed after the laser prescribe step.
[0078] In a further embodiment of this invention, illustrated in FIG. 5 , low energy laser pulses of a laser beam 54 are used in a first few passes along a dice lane 55 in order to prevent the development of large cracks propagating through active devices 51 when machining from an active device side of the wafers 50 , as shown in FIG. 5( i ) a. After the laser has cut through a depth of material approximately equal to an active device layer thickness a pulse energy E of the laser beam 54 can be increased to a higher pulse energy of a laser beam 541 under control of a laser cutting strategy file, as shown in FIG. 5( i ) b, in order to machine more quickly the bulk of a semiconductor substrate 53 of the wafer 50 , which is heated by the initial machining so that effects of thermal shock in machining the substrate 53 are reduced. When machining instead from a back side of a wafer substrate 53 , as shown in FIG. 5( ii ) a, opposed to a side caring the active devices 51 , a similar process can be adopted in order to prevent cracks propagating from the initial laser cut down through the substrate material and so the laser beam 54 with a low laser pulse energy is used initially. In the bulk of the semiconductor substrate 53 the laser energy is increased under control of a laser cutting strategy file using higher energy laser beam 541 for faster machining, see FIG. 5( ii ) b. When the laser beam 541 machining from the backside of the wafer 50 reaches a region containing active devices 51 , the laser pulse energy of the laser beam 54 is reduced under control of the laser cutting strategy file to prevent excessive damage in this region, see FIG. 5( ii ) c. In order to control laser machining in this manner, the laser cutting strategy file also contains data representative of a number of scans necessary to pass through the active layer and through the remainder of the substrate respectively, and the number of initial scans necessary to raise the temperature of the substrate to a temperature at which the effects of thermal shock are insignificant at the raised temperature and raised pulse energy.
[0079] In a further embodiment of the invention, illustrated in FIG. 9 , when machining, for example, a trench or dice lane 92 in, for example, a single layer substrate 93 , by multi-pass cutting, a laser beam 94 with lower pulse energy is used during an initial pass or passes Man a laser beam 941 used when cutting a bulk of the substrate in order to prevent, or at least to reduce to a lower degree than would otherwise occur, generation of surface micro-cracks in a first surface 91 from which the substrate 93 is machined. Similarly, the energy of final passes of a laser beam 942 may be reduced below that used for cutting the bulk of the substrate 93 , to prevent, or at least to reduce below a degree than would otherwise occur, chipping or cracking of a second surface 94 of the substrate opposed to the first surface 91 , or, for example, at a base of a trench. In the bulk of the substrate 93 higher energy pulses are used for efficient material removal. The pulse energy may be increased with increasing machining depth in order to facilitate more efficient material removal.
[0080] Moreover, referring to FIG. 10 , energy of a laser beam 104 may be varied throughout machining of a substrate 103 to facilitate removal of debris 109 generated by the machining. That is, a higher peak power of the laser beam 104 is used deep within the substrate than close to surfaces of the substrate.
[0081] The mechanical die strength of laser cut die is a function of the spatial overlap between consecutive laser pulses. The spatial overlap between consecutive laser pulses is therefore preferably chosen so as to yield optimum mechanical die strength of die obtained from a substrate to be machined. For example, the dependence of mechanical die strength of a silicon substrate machined using a 355 nm Q-switched laser is shown in FIG. 6 , where a probability of survival of a pressure test is plotted as ordinates against a pressure applied to a die as abscisa for a series of pulse overlaps from 30% to 76%. It is apparent in this case, that the plot 61 having the highest die strengths is obtained for a pulse overlap of 30%. It would appear that if the laser pulse overlap is too high there is too much heating in a region and too much cracking. If the laser pulse overlap is lower there is less thermal damage in a region and less cracking. In practice, a suitable overlap to give a required die strength and yield may be determined experimentally and stored in the laser cutting strategy file for use during machining. It will be understood that the spatial overlap of laser pulses is in fact a function of the scanning speed the pulse repetition rate and the diameter of the incident laser beam, so that only these parameters need be stored in the laser cutting strategy file.
[0082] When a telecentric lens is used to focus a laser beam the received laser intensity varies across a field of view of the telecentric lens. Laser parameters may be changed depending on the location of a focal spot within a field of view of the focusing scan lens objective in order to maintain a constant power density at the workpiece surface across the entire field of view. The variation in transmitted laser intensity as a percentage of incident laser intensity over the field of view of a typical telecentric scan lens is shown in a contour plot 20 in an upper half of FIG. 2 . Such a contour plot may be obtained by placing a laser power meter beneath the telecentric lens in a plane in which the substrate or workpiece is to be located. Laser power readings are recorded at a number of positions across the field of view of the lens (typically 40 mm×40 mm) and then plotted as a two dimensional surface plot. The irregularities in the laser power density map are mainly due to the quality of the antireflection coating on the lenses. A telecentric lens consists of a number of lenses and any irregularities in thickness or quality of the coating on any of these lenses can cause the observed irregularities in the laser power density map. Also, due to the geometry of a telecentric lens, its inherent performance is not so good at the edges of the field of view so the laser power density is reduced because of distortion in the laser beam profile caused by the telecentric lens itself.
[0083] Maintaining a constant power density across the entire scan lens field of view necessitates changing at least one of laser pulse energy and laser repetition frequency. In this embodiment of the invention, laser parameters are changed depending on the location of a focal spot within the field of view of the focusing objective in order to maintain a constant power density at the workpiece surface across the entire field of view. The variation in transmitted laser intensity as a percentage of incident laser intensity over the field of view of a typical telecentric scan lens is shown in FIG. 2 . Maintaining a constant power density across the entire scan lens field of view necessitates changing at least one of the laser pulse energy and the laser repetition rate and conveniently changing the laser pulse energy at a fixed laser repetition frequency or, alternatively, changing the laser repetition frequency at a fixed laser pulse energy. Power density (φ) is defined as the power (P in units of Watts) per unit area (A in units of centimetres squared) at the focal spot of the laser and is given by
[0000]
ϕ
=
P
A
[0084] Where the power equals the pulse energy (E in units of Joules) per second (s)
[0000]
P
=
E
s
[0085] By way of example, a lower half of FIG. 2 , which is a plot of pulse energy as ordinates versus distance along the line 21 , which is 10 mm from the lower edge of the field as seen in the upper half of FIG. 2 , demonstrates the modification of laser pulse energy that is required to maintain a constant power density at the substrate while scanning the laser across the field of view of the scan lens to compensate for the variation in transmitted laser intensity by the telecentric lens. In this example, the laser is scanned along straight line 21 which is 40 mm in length, 10 mm from the centre of the lens. In the upper half of FIG. 2 the field of view of the lens is divided into regions wherein the intensity at each point in a given region is within .+−.5% of all points in that region. For the 40 mm line 21 scanned by the laser in this example, six different regions, corresponding to six portions 22 , 23 , 24 , 25 , 26 , 27 of the scan line 21 , are traversed and as a result the laser energy is changed, under the control of the laser cutting strategy file, five times. The laser pulse energy starts at value 221 of E 4 in region 1 for a first portion 22 of scan line 21 . The transmitted laser intensity at the workpiece in region 1 is 80 to 85% of the laser intensity incident on the scan lens and as region 1 represents the region of lowest incident laser intensity compared to all the regions 2 to 6 , the energy per laser pulse E 4 in region 1 is consequently the highest. As the laser is scanned from region 1 to region 2 , corresponding to a second portion 23 of scan line 21 , the transmitted laser intensity increases to 85 to 90% of the laser intensity incident on the scan lens and in order to maintain a constant power density on the surface of the workpiece the laser pulse energy is now reduced to a value 231 of E 3 , where E 3 is 5% lower in energy than E 4 . As the laser beam traverses from one region to the next the laser pulse energy is changed, under control of the laser cutting strategy file, ‘on the fly’ (on a pulse to pulse basis if required) in order to maintain a constant value of power density (φ) at the workpiece surface along the entire 40 mm length of the dice lane 21 .
[0086] In summary, the laser power density φ at the workpiece surface is directly proportional to the laser pulse energy E. The value of the laser pulse energy at the workpiece surface will differ from that emerging directly from the laser due to attenuation in the scan lens. The contour map is stored as a two dimensional array in a computer memory associated with a computer control of the laser and depending on where the software directs the galvanometer scanner to place the laser beam in the field of view, a simultaneous command is sent to the laser to change the pulse repetition rate and the laser pulse energy as indicated in the laser cutting strategy file. Laser power may also be monitored by an integral power meter in the laser head itself and any variation in power in the laser can be compensated for. In principle, rather than storing the contour map the laser power could be monitored at the workpiece or substrate but there would be a loss of laser power in doing so, and preferably the contour map is stored in memory. In accordance with the invention, the combination of pulse repetition rate and pulse energy are controlled during scanning, the laser pulse energy E is varied in indirect proportion to the transmission of the telecentric scan lens, in order to maintain a constant power density at the workpiece surface across the entire field of view of the scan lens. This permits, for example, the machining of dice lanes and pre-scribing trenches of uniform depth, where the depth of the dice lane is directly proportional to the power density cp. In instances where a substrate is laser machined so that the laser cuts down through the entire thickness of the substrate, maintaining uniform power density across the entire dice lane prevents partial cutting of dice lanes. Partial cutting of dice lanes leaves material between adjacent die and during the pick and place process, when die are picked from a transport tape, such die which are stuck together may break apart causing damage to the die, thus reducing significantly their mechanical strength.
[0087] Laser dicing in accordance with the invention may be performed in a non-ambient gas environment controlled by a gas handling system. Gas parameters such as S flow rate, concentration, temperature, gas type and gas mixes may be controlled at least one of prior to, during and after the laser dicing process. A series of different gases may be used at least one of prior to, during and after the laser machining processes.
[0088] A gas delivery head may be used to ensure gas is uniformly delivered to a cutting region of the substrate such that uniform cutting is achieved.
[0089] Gases used may be passive or reactive with respect to the semiconductor substrate and/or layers in the semiconductor wafer or substrate. Inert gases (e.g. argon and helium) may be used to prevent growth of an oxide layer on the die walls during laser machining. Gases that react with silicon (e.g. chlorofluorocarbons and halocarbons) may be used at least one of prior to, during and after laser machining to reduce the surface roughness of die sidewalls by etching the substrate material. Also, a heat affected zone (HAZ) produced on the die sidewalls as a result of laser machining can be etched away using a reactant gas. In this way the quality of the die sidewalls is improved and therefore the die strength is increased. Also reactive gases reduce the amount of debris adhering on die sidewalls and top and bottom surfaces, thus reducing potential stress points on laser machined die.
[0090] In a further embodiment of this invention, the laser pulse energy is reduced to a value close to the melting threshold of the wafer material (after die singulation) and the laser is scanned along the die edge in order to heat (rather than ablate) the die sidewalls. In doing so, the surface roughness of the die sidewalls is reduced and the uniformity of the heat affected zone is increased, thus resulting in increased die strength.
[0091] In a further embodiment of his invention, the laser is scanned in such a way as to machine die 71 with rounded corners 72 as shown in FIG. 7( i ). Die 75 diced with a conventional mechanical saw according to the prior art are shown in FIG. 7( ii ). Rounded corner geometry is easier to achieve and is more accurate when using a galvanometer based laser machining system rather than a conventional mechanical saw based dicing system. However, the laser pulse properties must be changed at the rounded corner sections if as is typically the case, the galvanometer scanning mirrors used to direct the laser beam have to slow down as they traverse the curved features. Otherwise, when the scanning mirrors slow down the laser pulse spatial overlap would increase, therefore the time between pulses, Δt, needs to be increased in order to maintain an overlap on the rounded corner sections that is the same as a spatial overlap used on sight regions of the die. This data is stored in the laser cutting strategy file for controlling the laser beam during machining. Using a laser to produce die with rounded corners improves die strength and enables dicing of thin wafers. The rounded corners eliminate stresses that are induced by sharp corners of rectangular die.
[0092] In addition, machining may be controlled by the laser cutting strategy file and program control such that pulse delivery on a corner or curved portion of a die edge is such that a “clear” corner or curved section is obtained with no over-cutting or undercutting which may otherwise generate a defect at the die edge.
[0093] In a further embodiment of the invention, the taper of a laser dice lane 85 , cut with a laser beam 84 in a substrate 83 , may be varied in order to produce convex arcuate die sidewalls 82 , as shown in FIG. 8 , to produce a cut which tapers in a direction of the laser beam 84 . As in the previously described embodiment, this results in increased die strength by removing potential stress points at sharp corners. Tapering of the dice lane sidewalls is achieved by varying the width of the dice lane as the laser beam scans down through the substrate. The tapered sidewalls shown in FIG. 8 are achieved by reducing the number of adjacent laser scans in the dice lane as the depth machined into the substrate increases.
[0094] As illustrated in FIG. 10 , a substrate 103 to be machined may be mounted on a transport tape 110 , for example to singulate die 101 by machining dice lanes 102 in the substrate 103 in that case, the laser beam energy may be controlled in final passes through the substrate to ensure that damage to the tapes does not occur, as described above in relation to FIG. 9( iii ). Alternatively, or in addition, a tape 110 may be used, such as a polyolefin-based tape, which is substantially transparent to an ultraviolet laser light beam 104 used to machine the substrate 103 , such that, with suitable choices of machining process parameters, substantially no damage occurs to the tape.
[0095] The invention is not limited to the embodiments described but may be varied in construction and detail.
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A substrate is diced using a program-controlled pulsed laser beam apparatus having an associated memory for storing a laser cutting strategy file. The file contains selected combinations of pulse rate Δt, pulse energy density E and pulse spatial overlap to machine a single layer or different types of material in different layers of the substrate while restricting damage to the layers and maximising machining rate to produce die having predetermined die strength and yield. The file also contains data relating to the number of scans necessary using a selected combination to cut through a corresponding layer. The substrate is diced using the selected combinations. Gas handling equipment for inert or active gas may be provided for preventing or inducing chemical reactions at the substrate prior to, during or after dicing.
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FIELD OF INVENTION
[0001] The present invention relates to dihydroartemisinin and dihydroartemisitene dimers and their use in the treatment of cancer and as antiprotzoal agents.
BACKGROUND OF THE INVENTION
[0002] Cancer deaths in the U.S. alone were over 500,000 in 2001, and in spite of many advances, cancer remains one of the leading killers (1). There is a critical need for the development of new anti-cancer agents, especially those with novel and selective mechanisms of action. Although some of the promise of non-cytotoxic therapies is beginning to be realized (e.g. immunostimulants, growth factor antagonists, anti-sense therapy), the mainstay of the treatment of most cancers remains with cytotoxic drugs. In view of the limited success rates, incidence of toxicities, and development of resistance to such agents, there is a dire need for new classes of these drugs, especially those that may act by new mechanisms or exhibit exploitable selectivity. There is also a need for a better understanding of dosing, scheduling, and concomitant therapies in order to optimize treatment protocols.
[0003] Natural products have historically been a rich source of new, successful prototype classes of lead compounds from which analogs have been developed. According to a recent review, 60% of the anti-infective and anti-cancer drugs that have successfully advanced to the clinic are derived from natural products (2). Examples of these among currently used anti-cancer agents include the anthracycline class (e.g., doxorubicin), the Catharanthus (Vinca) alkaloids, paclitaxel, and derivatives of podophyllotoxin and camptothecin. A recently published tabulation of natural product-based anti-tumor drugs shows more than 25 agents currently in Phase I or II (3). This and other recent reviews are important reminders of the critical role of natural products as a resource for the discovery of new anti-tumor agents (4,5).
[0004] The natural product artemisinin (1) is a sesquiterpene endoperoxide first isolated in 1971 from the Chinese plant Artemisia annua (6). The compounds as numbered herein are depicted in FIG. 1 . The compound was shown to have anti-malarial activity against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum.
[0005] Because of the importance of the clinical effects of artemisinin in treating malaria, many derivatives were prepared in order to develop the most effective and least toxic anti-malarial agent. Initially, simple derivatives were prepared—e.g., dihydroartemisinin (DHA, in which the lactone carbonyl is reduced resulting in a hemiacetal), artemether (the methyl ether of DHA) and several other ether and ester analogs. The sodium salt of the hemisuccinate ester (sodium artesunate) was one of these derivatives that showed more activity and less toxicity than artemether, the latter being more active than artemisinin itself. Continued interest in the activity of artemisinin and DHA analogs later resulted in the preparation of artemisinin acetal dimers through reaction of dihydroartemisinin with borontrifluoride-etherate.
[0006] In addition to its anti-malarial activity, artemisinin had been reported to have cytotoxic effects against EN-2 tumor cells (7), P-388, A549, HT-29, MCF-7, and KB-tumor cells (8). As more analogs were evaluated for anti-tumor activity, it was reported that the unsymmetrical dimer (2) showed strong cytotoxic activity and was more potent than cisplatin (9). The symmetrical dimer (3) also showed pronounced cytotoxic activity (10).
[0007] This finding stimulated interest in other types of DHA dimers. Posner et al. (11) prepared dimers linked with a polyethylene glycol spacer (3 units of ethylene glycol), an eight carbon glycol, and a dithio-derivative. The authors also prepared simpler trioxane dimers. Posner et al. also prepared several dimers of DHA where the linking units between the two molecules of dihydroartemisinin were dicarboxylic acids of different types (12). Zhang and Darbie (13,14) also proposed several dihydroartemisinin dimers to be linked via different coupling agents. Some of these artemisinin dimers and some of the simpler trioxanes had anti-malarial effects, anti-cancer activity, and anti-proliferative effects with some compounds being as active as calcitriol in an anti-proliferative assay in murine keratinocytes.
[0008] More recently, ElSohly et al (15) prepared a series of DHA dimers with 1,2- and 1,3-glycols which were active in the anticancer screen carried out at the National Cancer Institute (NCI). The compounds showed promising selectivity in the 60-cell line anticancer screen, as well as activity in the anti-malarial and anti-leishmanial screens. While these dimers have good activity in the anticancer and anti-protozoal screens, they have limited water solubility which impose difficulties in formulation.
SUMMARY OF THE INVENTION
[0009] This invention comprises compositions containing dihydroartemisinin and dihydroartemisitene dimers with activity as anticancer agents and anti-protozoal, including anti-malarial and anti-leishmanial properties. This invention also describes methods of preparation of these compositions and methods of use of such compositions for the treatment of cancer, and protozoal infections, including malaria, or leishmaniasis. The compositions of this invention have not been previously described.
[0010] The compounds of this invention represent a potential new class of anti-tumor agents, one that has shown promising activity and with chemical functionalities that will improve formulation characteristics.
DESCRIPTION OF THE INVENTION
[0011] In the interest of development of new chemotherapeutic agents, artemisinin dimers were prepared in this invention by condensation of DHA with dihydroxy acetone to generate the dimer depicted in structure 4 which is used as the starting material for all dimers based on DHA and the corresponding analogs based on dihydroartemisitene.
[0012] The present invention relates to compounds of the formula:
[0000]
[0000] where R is
[0000]
[0000] where R 1 is H or alkyl, cycloalkyl or aryl moiety, free or containing one of a variety of functional groups such as COOH, OH, NH or derivatives thereof;
where R 2 is H or alkyl, cycloalkyl or aryl moiety, free or containing one of a variety of functional groups such as COOH, OH, NH 2 or derivatives thereof;
where R 3 is an alkyl, cycloalkyl or aryl residue with acidic functional group (such as COOH), a sulfate (SO 3 H), a phosphate (PO 3 H 2 ) ester or basic functionality (such as primary, secondary or tertiary amine) and R 4 is H; OR where R 3 is H and R 4 is an alkyl, cycloalkyl or aryl residue with acidic or basic functionality; OR where R 4 is H and R 3 is an ester or carbamate residue, such residue might be containing other functional groups such as COOH, OH, amino, or sugar moiety;
or compounds of the formula
[0000]
[0000] where R 5 is selected from one of the substituents described above for R.
[0013] Furthermore, the present invention includes pharmaceutical compositions comprising at least one of the compounds according to the above formulas and pharmaceutically acceptable carrier and/or excipient.
[0014] The compounds of the invention can be prepared by reacting dihydroartemisin or dihydroartemistene with dihydroxy acetone under acidic conditions such as borontrifluoride etherate followed by additional functionalization of the resulting ketone dimer.
[0015] Compounds where R is
[0000]
[0000] residue and R 1 is selected from H, or alkyl, cycloalkyl or aryl groups free or containing one of a variety of functional groups such as COOH, OH or NH 2 or derivatives thereof are prepared by reacting the ketone dimer from the reaction product of DHA with dihyrdroxy acetone with NH 2 —O—R 1 (where R 1 is the appropriate substituent) under basic conditions followed by purification of the reaction mixture to separate the purified oxime.
[0016] Compounds where R is
[0000]
[0000] residue and R 2 is selected from H, or alkyl, cycloalkyl or aryl groups free or containing one of a variety of functional groups such as COOH, OH or NH 2 or derivatives thereof are prepared by reacting the ketone dimer from dihydroxy acetone with NH 2 —R 2 (where R 2 is the appropriate substituent) and sodium cyanoborohydride or sodium triacetoxyborohydride, followed by purification of the reaction mixture to separate the purified amine. Alternatively, compounds where R is
[0000]
[0000] could be directly prepared by reacting DHA with the 1,3-diol containing the appropriate substituent at the 2 position, in the presence of an acid catalyst such as borontrifluoride etherate.
[0017] Compounds where R is
[0000]
[0000] residue and where R 3 is an alkyl, cycloalkyl or aryl residue with acidic functional group (such as COOH), a sulfate (SO 3 H), a phosphate (PO 3 H 2 ) ester, or basic functionality (such as primary, secondary or tertiary amine) and R 4 is H; OR where R 3 is H and R 4 is an alkyl, cycloalkyl or aryl residue with acidic or basic functionality; OR where R 4 is H and R 3 is an ester or carbamate residue, such residue might be containing functional groups such as COOH, OH, amino, or sugar moiety, are prepared by reacting the ketone dimer from dihydroxy acetone with the proper nucleophile or by first reducing the ketone dimer with sodium borohydride followed by reacting the resulting alcohol with the proper reagent to produce the desired product.
[0018] Compounds where R 5 is
[0000]
[0000] residue and R 1 is selected from H, or alkyl, cycloalkyl or aryl groups free or containing one of a variety of functional groups such as COOH, OH or NH or derivatives thereof are prepared by reacting the ketone dimer of dihydroxy acetone and dihydroartemisitene with NH 2 —O—R 1 (where R 1 is the appropriate substituent) under basic conditions followed by purification of the reaction mixture to separate the purified oxime.
[0019] Compounds where R 5 is
[0000]
[0000] residue and R 2 is selected from H, or alkyl, cycloalkyl or aryl groups free or containing one of a variety of functional groups such as COOH, OH or NH 2 or derivatives thereof are prepared by reacting the ketone dimer from dihydroxy acetone and dihydroartemisitene with NH 2 —R 2 (where R 2 is the appropriate substituent) and sodium cyanoborohydride or sodium triacetoxyborohydride, followed by purification of the reaction mixture to separate the purified amine.
[0020] Compounds where R 5 is
[0000]
[0000] residue and where R 3 is an alkyl, cycloalkyl or aryl residue with acidic functional group such as COOH, a sulfate (SO 3 H), a phosphate (PO 3 H 2 ) ester, or basic functionality (such as primary, secondary or tertiary amine) and R 4 is H; OR where R 3 is H and R 4 is an alkyl, cycloalkyl or aryl residue with acidic or basic functionality; OR where R 4 is H and R 3 is an ester or carbamate residue, such residue might be containing functional groups such as COOH, OH, amino, or sugar moiety are prepared by reacting the ketone dimer from dihydroxy acetone and dihydroartemisitene with the proper nucleophile or by first reducing the ketone dimer with sodium borohydride followed by reacting the resulting alcohol with the proper reagent to produce the desired product.
[0021] As used herein, the term “alkyl” refers to a straight or branched chain hydrocarbon having from one to ten carbon atoms, optionally substituted with appropriate substituents. Examples of “alkyl” as used herein include, but are not limited to, methyl, ethyl, propyl, n-butyl, t-butyl, n-pentyl, isobutyl, and isopropyl, and the like.
[0022] As used herein, “cycloalkyl” refers to an alicyclic hydrocarbon group optionally possessing one or more degrees of unsaturation, having from three to six carbon atoms, optionally substituted with appropriate substituents.
[0023] “Cycloalkyl” includes by way of example cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl, and the like.
[0024] As used herein, the term “aryl” refers to a benzene ring, optionally substituted with appropriate substituents. Examples of aryl include, but are not limited to, phenyl.
[0025] The invention further comprises a method of treating cancer, prevention or control of cancer metastasis or treating protozoal infections, comprising administering to a subject suffering from cancer or a protozoal infection an effective amount of at least one compound of one of the formulae:
[0000]
[0000] where R is
[0000]
[0000] where R 1 is H or alkyl, cycloalkyl or aryl moiety, free or containing one of a variety of functional groups such as COOH, OH, NH or derivatives thereof;
where R 2 is H or alkyl, cycloalkyl or aryl moiety, free or containing one of a variety of functional groups such as COOH, OH, NH or derivatives thereof;
where R 3 is an alkyl, cycloalkyl or aryl residue with acidic functional group such as COOH, a sulfate (SO 3 H), a phosphate (PO 3 H 2 ) ester or basic functionality (such as primary, secondary or tertiary amine) and R 4 is H; OR where R 3 is H and R 4 is an alkyl, cycloalkyl or aryl residue with acidic or basic functionality; OR where R 4 is H and R 3 is an ester or carbamate residue, such residue might be containing functional groups such as COOH, OH, amino, or sugar moiety;
or a compound of the formula:
[0000]
[0000] where R 5 is selected from one of the substituents described above for R.
[0026] Administration of the instant dimers may be by any of the conventional routes of administration, for example, oral, subcutaneous, intraperitoneal, intramuscular, intravenous or rectally. In the preferred embodiment, the compound is administered in combination with a pharmaceutically-acceptable carrier which may be solid or liquid, dependent upon choice and route of administration. Examples of acceptable carriers include, but are not limited to, starch, dextrose, sucrose, lactose, gelatin, agar, stearic acid, magnesium stearate, acacia, and similar carriers. Examples of liquids include saline, water, buffer solutions, edible oils, e.g. peanut and corn oils.
[0027] When administered in solid form, the compound and diluent carrier may be in the form of tablets, capsules, powders, or suppositories, prepared by any of the well known methods. When given as a liquid preparation, the mixture of active compound and liquid diluent carrier may be in the form of a suspension administered as such, an emulsion, or a true solution. The compound is administered in a non-toxic dosage concentration sufficient to inhibit the growth and/or destroy cancer or prevent cancer metastasis or to destroy protozoal organisms such as malaria and leishmania . The actual dosage unit will be determined by the well recognized factors as body weight of the patient and/or severity and type of pathological condition the patient might be suffering with. With these considerations in mind, the dosage unit for a particular patient can be readily determined by the medical practitioner in accordance with the techniques known in the medical arts.
[0028] The compounds of this invention have been prepared by reaction of dihydroartemisinin or dihydroartemisitene with dihydroxy acetone to produce the dimeric ketone under acidic conditions (borontrifluoride etherate) in dry ether followed by subsequent functionalization of the purified ketone dimer to produce the desired product. Optional functionalizations include, for example, the preparation of oximes, amines, substituted alcohols with different functionalities or reduction of the ketone dimer to its dihydro derivative (alcohol) followed by functionalization of the resulting OH group to produce a variety of ester, carbamates, sulfates, phosphates, etc. . . . The starting material (dihydroartemisinin) is prepared by sodium borohydride reduction of the natural product artemisinin (1). The latter compound is isolated from the leaves of Artemisia annua following the procedures previously described (16, 17). Similarly, dihydroartemisitene is derived from artemisitene, a constituent of the same plant. The compounds of the invention were tested for anti-tumor activity and in the anti-malarial and anti-Leishmanial screens. The activities are shown in Tables 1-3.
EXAMPLES
[0029] Reactions were run in oven dried round-bottomed flasks. Diethyl ether (ether) was distilled from sodium benzophenone ketyl prior to use under an atmosphere of argon. All chemicals were purchased from Sigma-Aldrich and used without further purification. Artemisinin (1) was isolated from locally grown Artemisia annua L. plants, using a literature procedure (16, 17), and was reduced to dihydroartemisinin as previously reported (18).
[0030] Column chromatography was performed using flash chromatography, using silica gel purchased from Merck (particle size 230-400 mesh). Analytical thin-layer chromatography (TLC) was performed with silica gel 60 F 254 plates (250 μm thickness; Merck), using n-hexane-EtOAc or CH 2 CL 2 -EtOAc mixtures or other solvent systems as needed. Visualization was accomplished by spraying with p-anisaldehyde spray reagent followed by heating using a hot-air gun (19) or with a solution of H 2 SO 4 in EtoH followed by heating.
[0031] Spectral data were obtained as follows. 1D and 2D NMR spectra were obtained on Bruker Avance DRX 500 spectrometers at 500 MHz ( 1 H) and 125 MHz ( 13 C) or Bruker DRX 400 spectrometer using the solvent peak as the internal standard. HREIMS were obtained using an Agilent Time-Of-Flight LCMS.
Example 1
Preparation of the Oxime of the β,β-Dihydroartemisinin Dimer with Dihydroxyacetone (6)
[0032] β,β-Dihydroartemisinin dimer with dihydroxyacetone (4) (50 mg, 0.08 mmol), sodium acetate (40 mg, 0.48 mmol) and aminoxy-acetic acid (9.1 mg, 0.10 mmol, 1.2 eq) were mixed in 5 ml of dichloromethane (freshly distilled) and the mixture refluxed for 4 hours under argon. TLC indicated the completion of the reaction.
[0033] The resulting reaction product was evaporated to dryness, the residue dissolved in 6 ml of ethyl acetate, washed with water, dried over anhydrous sodium sulphate and the solvent evaporated to dryness.
[0034] The residue was chromatographed on silica gel column (300 mg) and eluted with chloroform with polarity increasing to 90:10 chloroform:methanol. Fractions were collected and combined according to TLC similarities to give one major fraction having the desired product (41.1 mg), with spectral data consistent with structure 6.
[0035] 1 H-NMR in CDCl 3 at 400 MHz: δ 8.23 (1H, br s, OH); 5.41 and 5.38 (1H each, s each, H-5 and H-5′); 4.85 and 4.81 (1H each, d each, J=3.2 Hz each, H-12 and H-12′); 4.65 and 4.38 (2H each, br d each, J=14.8 and 15.6 Hz, respectively, H-16 and H-16′); 4.62 (2H, s, H-18); 2.63, (2H, br m, H-11 and H-11′); 2.34 and 2.01 (2H each, br t and br d, respectively, J=13.6 and 14.4 Hz, respectively, H-3 and H-3′); 1.85 and 1.50 (2H each, m each, H-2 and H-2′); 1.73 (4H, br t, J=11.2 Hz, H-9 and H-9′); 1.61 and 1.46 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.41 (6H, s, Me-15 and Me-15′); 1.22 (2H, m, H-1 and H-1′); 0.94-0.82 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0036] 13 C-NMR in CDCl 3 at 100 MHz: δ 174.10 (s, C═O); 156.78 (s, C═N); 104.20 and 104.14 (s, C-4 and C-4′); 102.34 and 100.73 (d, C-12 and C-12′); 87.97 (d, C-5 and C-5′); 81.04 and 80.96 (s, C-6 and C-6′); 70.35 (t, C-18); 64.69 and 61.59 (t, C-16 and C-16′); 52.47 (d, C-1 and C-1′); 44.29 (d, C-7 and C-7′); 37.42 (d, C-10 and C-10′); 36.36 (t, C-3 and C-3′); 34.59 (t, C-9 and C-9′); 30.80 (d, C-11 and C-11′); 26.06 and 26.03 (q, C-15 and C-15′); 24.46 (t, C-2 and C-2′); 24.41 (t, C-8 and C-8′); 20.36 (q, C-14 and C-14′); 12.96 (q, C-13 and C-13′).
[0037] HREIMS: (m/z) 718.3190 [M+Na], (calcd. for C 35 H 53 NO 13 , 695.3517).
Example 2
Preparation of the Oxime of the β,β-Dihydroartemisinin Dimer with Dihydroxyacetone (7)
[0038] β,β-Dihydroartemisinin dimer with dihydroxyacetone (4) (100 mg, 0.16 mmol), sodium acetate (80 mg, 0.48 mmol) and hydroxylamine hydrochloride (14 mg, 0.20 mmol, 1.3 eq) were mixed in 10 ml of dichloromethane (freshly distilled) and refluxed for 0.5 hours under argon. TLC indicated the completion of the reaction.
[0039] The resulting reaction product was evaporated to dryness, the residue dissolved in 6 ml of ethyl acetate, washed with water, dried over anhydrous sodium sulphate and the solvent evaporated to dryness.
[0040] The residue was chromatographed on silica gel column and eluted with hexane:ethyl acetate (90:10) with polarity increasing to 70:30. Fractions were collected and combined according to TLC similarities to give one major fraction having the desired product (76.0 mg), with spectral data consistent with structure 7.
[0041] 1 H-NMR in CDCl 3 at 400 MHz: δ 5.42 (2H, s, H-5 and H-5′); 4.84 and 4.80 (1H each, d each, J=2.4 Hz each, H-12 and H-12′); 4.65, 4.39, 4.37 and 4.16 (1H each, d each, J=14.0, 11.6, 14.0 and 12.0 Hz, respectively, H-16 and H-16′); 2.66, (2H, m, H-11 and H-11′); 2.38 and 2.03 (2H each, ddd and br d, respectively, J=2.8 Hz each, H-3 and H-3′); 1.87 and 1.51 (2H each, m each, H-2 and H-2′); 1.74 (4H, m, H-9 and H-9′); 1.62 and 1.48 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.43 (6H, s, Me-15 and Me-15′); 1.26 (2H, m, H-1 and H-1′); 0.96-0.89 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0042] 13 C-NMR in CDCl 3 at 100 MHz: δ 155.21 (s, C═N); 104.16 and 104.13 (s, C-4 and C-4′); 102.48 and 101.05 (d, C-12 and C-12′); 87.93 (d, C-5 and C-5′); 81.02 and 80.98 (s, C-6 and C-6′); 64.42 and 60.24 (t, C-16 and C-16′); 52.55 (d, C-1 and C-1′); 44.38 (d, C-7 and C-7′); 37.44 and 37.39 (d, C-10 and C-10′); 36.43 (t, C-3 and C-3′); 34.66 (t, C-9 and C-9′); 30.87 and 30.72 (d, C-11 and C-11′); 26.05 (q, C-15 and C-15′); 24.64 (t, C-2 and C-2′); 24.52 (t, C-8 and C-8′); 20.32 (q, C-14 and C-14′); 13.06 and 12.96 (q, C-13 and C-13′).
[0043] HREIMS: (m/z) 660.3343 [M+Na], 676.3058 [M+K], (calcd. for C 33 H 51 NO 11 , 637.3462).
Example 3
Preparation of the Oxime of the β,β-Dihydroartemisinin Dimer with Dihydroxyacetone (8)
[0044] β,β-Dihydroartemisinin dimer with dihydroxyacetone (4) (100 mg, 0.16 mmol), sodium acetate (80 mg, 0.48 mmol) and O-benzyl hydroxylamine hydrochloride (28.1 mg, 0.18 mmol, 1.1 eq) were mixed in 5 ml of dichloromethane (freshly distilled) and refluxed for 18 hours under argon. TLC indicated the completion of the reaction.
[0045] The resulting reaction product was evaporated to dryness, the residue dissolved in 6 ml of ethyl acetate, washed with water, dried over anhydrous sodium sulphate and the solvent evaporated to dryness.
[0046] The residue was chromatographed on silica gel column and eluted with dichloromethane with polarity increasing to 90:10 dichloromethane:ethyl acetate. Fractions were collected and combined according to TLC similarities to give one major fraction having the desired product (64 mg), with spectral data consistent with structure 8.
[0047] 1 H-NMR in CDCl 3 at 400 MHz: δ 7.35 (5H, m, H-20 to H-24); 5.43 and 5.39 (1H each, s each, H-5 and H-5′); 5.12 (2H, s, H-18); 4.86 and 4.80 (1H each, d each, J=3.2 Hz each, H-12 and H-12′); 4.67, 4.42, 4.35 and 4.20 (1H each, d each, J=14.4, 12.0, 14.0 and 12.4 Hz, respectively, H-16 and H-16′); 2.65, (2H, m, H-11 and H-11′); 2.38 and 2.05 (2H each, br t and br d, respectively, J=14.0 and 11.6 Hz, respectively, H-3 and H-3′); 1.86 and 1.49 (2H each, m each, H-2 and H-2′); 1.73 (4H, m, H-9 and H-9′); 1.60 and 1.48 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.44 (6H, s, Me-15 and Me-15′); 1.26 (2H, m, H-1 and H-1′); 0.97-0.92 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0048] 13 C-NMR in CDCl 3 at 100 MHz: δ 155.00 (s, C═N); 137.66 (s, C-19); 128.31 (d, C-20 and C-24); 127.96 (d, C-21 and C-23); 127.76 (d, C-22); 104.06 and 104.03 (s, C-4 and C-4′); 102.49 and 100.93 (d, C-12 and C-12′); 87.95 and 87.91 (d, C-5 and C-5′); 81.02 and 80.94 (s, C-6 and C-6′); 76.23 (t, C-18); 65.27 and 61.75 (t, C-16 and C-16′); 52.59 and 52.55 (d, C-1 and C-1′); 44.42 and 44.41 (d, C-7 and C-7′); 37.39 and 37.37 (d, C-1 and C-10′); 36.47 and 36.45 (t, C-3 and C-3′); 34.70 and 34.65 (t, C-9 and C-9′); 30.87 and 30.74 (d, C-11 and C-11′); 26.15 and 26.14 (q, C-15 and C-15′); 24.64 and 24.63 (t, C-2 and C-2′); 24.49 and 24.43 (t, C-8 and C-8′); 20.36 (q, C-14 and C-14′); 13.06 and 12.96 (q, C-13 and C-13′).
[0049] HREIMS: (m/z) 750.3841 [M+Na], (calcd. for C 40 H 57 NO 11 , 727.3932).
Example 4
Preparation of the Oxime of the β,β-Dihydroartemisinin Dimer with Dihydroxyacetone (9)
[0050] β,β-Dihydroartemisinin dimer with dihydroxyacetone (4) (100 mg, 0.16 mmol), sodium acetate (80 mg, 0.48 mmol) and O-ethyl hydroxylamine hydrochloride (17.0 mg, 0.17 mmol, 1.1 eq) were mixed in 5 ml of dichloromethane (freshly distilled) and refluxed for 5.5 hours under argon. TLC indicated the completion of the reaction.
[0051] The resulting reaction product was evaporated to dryness, the residue dissolved in 6 ml of ethyl acetate, washed with water, dried over anhydrous sodium sulphate and the solvent evaporated to dryness.
[0052] The residue was chromatographed on silica gel column and eluted with dichloromethane with polarity increasing to 90:10 dichloromethane:ethyl acetate. Fractions were collected and combined according to TLC similarities to give one major fraction having the desired product (51.7 mg), with spectral data consistent with structure 9.
[0053] 1 H-NMR in CDCl 3 at 400 MHz: δ 5.36 and 5.32 (1H each, s each, H-5 and H-5′); 4.79 and 4.72 (1H each, d each, J=3.2 and 2.8 Hz, respectively, H-12 and H-12′); 4.52, 4.31, 4.23 and 4.09 (1H each, d each, J=14.4, 12.0, 14.0 and 12.0 Hz, respectively, H-16 and H-16′); 4.02 (2H, q, J=7.2 Hz, H-18); 2.57, (2H, m, H-11 and H-11′); 2.29 and 1.94 (2H each, br t and br d, respectively, J=14.0 and 10.4 Hz, respectively, H-3 and H-3′); 1.78 and 1.49 (2H each, br m each, H-2 and H-2′); 1.78 (4H, m, H-9 and H-9′); 1.68 and 1.40 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.35 (6H, s, Me-15 and Me-15′); 1.26 (2H, m, H-1 and H-1′); 1.18 (3H, t, J=6.8 Hz, Me-19); 0.89-0.81 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0054] 13 C-NMR in CDCl 3 at 100 MHz: δ 153.94 (s, C═N); 103.94 and 103.89 (s, C-4 and C-4′); 102.37 and 100.71 (d, C-12 and C-12′); 87.83 and 87.81 (d, C-5 and C-5′); 80.90 and 80.83 (s, C-6 and C-6′); 65.22 and 62.59 (t, C-16 and C-16′); 69.68 (t, C-18); 52.50 and 52.48 (d, C-1 and C-1′); 44.35 and 44.31 (d, C-7 and C-7′); 37.37 and 37.33 (d, C-10 and C-10′); 36.37 and 36.35 (t, C-3 and C-3′); 34.64 and 34.60 (t, C-9 and C-9′); 30.79 and 30.67 (d, C-11 and C-11′); 26.04 (q, C-15 and C-15′); 24.60 (t, C-2 and C-2′); 24.42 and 24.35 (t, C-8 and C-8′); 20.30 (q, C-14 and C-14′); 14.49 (q, C-19); 13.04 and 12.95 (q, C-13 and C-13′).
[0055] HREIMS: (m/z) 688.3704 [M+Na], (calcd. for C 35 H 55 NO 11 , 665.3775).
Example 5
Preparation of the Sulphate of the β,β-Dihydroartemisinin Dimer with Glycerol (10)
[0056] β,β-Dihydroartemisinin dimer with glycerol (5) (90 mg, 0.14 mmol) was dissolved in 2.5 ml of pyridine. Temperature was adjusted to −18° C. at which time 10 eq. of chlorosulfonic acid was added (as reaction is very violent, chlorosulfonic acid was added dropwise). After complete addition of chlorosulfonic acid the mixture was allowed to stir overnight at room temperature under argon. In the morning, TLC indicated the completion of the reaction. Acetic acid was added to the reaction mixture and the product was extracted with 3×30 ml of dichloromethane, dried over anhydrous sodium sulfate and evaporated to dryness.
[0057] The residue was chromatographed on silica gel column and eluted with ethyl acetate with polarity increasing to 80:20 ethyl acetate:methanol. Fractions were collected and combined according to TLC similarities to give one major fraction having the desired product (39.2 mg), with spectral data consistent with structure 10.
[0058] 1 H-NMR in CDCl 3 at 400 MHz: δ 5.45 (1H, s, H-17); 5.38 and 5.27 (1H each, s each, H-5 and H-5′); 4.86 and 4.78 (1H each, s each, H-12 and H-12′); 4.07 (4H, br t, J=6.8 Hz, H-16 and H-16′); 2.56, (2H, m, H-11 and H-11′); 2.30 and 2.01 (2H each, br t each, J=12.0 Hz each, H-3 and H-3′); 1.82 and 1.60 (2H each, m each, H-2 and H-2′); 1.72 (4H, br t, J=10.2 Hz, H-9 and H-9′); 1.71 and 1.62 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.39 (6H, s, Me-15 and Me-15′); 1.22 (2H, m, H-1 and H-1′); 0.91-0.86 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0059] 13 C-NMR in CDCl 3 at 100 MHz: δ 104.38 and 104.20 (s, C-4 and C-4′); 102.48 and 101.71 (d, C-12 and C-12′); 88.05 and 87.94 (d, C-5 and C-5′); 81.04 and 80.99 (s, C-6 and C-6′); 76.13 (d, C-17); 65.96 and 65.72 (t, C-16 and C-16′); 52.61 and 52.56 (d, C-1 and C-1′); 44.46 and 44.40 (d, C-7 and C-7′); 37.23 (d, C-10 and C-10′); 36.44 and 36.36 (t, C-3 and C-3′); 34.69 (t, C-9 and C-9′); 30.89 and 30.82 (d, C-11 and C-11′); 25.97 and 25.85 (q, C-15 and C-15′); 24.61 (t, C-2 and C-2′); 24.45 (t, C-8 and C-8′); 20.37 (q, C-14 and C-14′); 12.98 (q, C-13 and C-13′).
[0060] HREIMS: (m/z) 703.2942 [M−H], (calcd. for C 35 H 52 SO 14 , 704.3078).
Example 6
Preparation of the Carbamate of the β,β-Dihydroartemisinin Dimer with Glycerol (11)
[0061] β,β-Dihydroartemisinin dimer with glycerol (5) (200 mg, 0.32 mmol) was dissolved in 5.0 ml of dichloromethane and 4-nitrophenyl chloroformate (1.1 eq.) was added to it. The reaction was allowed to run under argon at room temperature overnight and 1.1 eq. of 4-amino butyric acid allyl ester was added to it. The reaction was stirred for 24 hours and continuous monitoring of TLC indicated no more conversion of starting material to the
Example 6
Preparation of the Carbamate of the β,β-Dihydroartemisinin Dimer with Glycerol (11)
[0062] β,β-Dihydroartemisinin dimer with glycerol (5) (200 mg, 0.32 mmol) was dissolved in 5.0 ml of dichloromethane and 4-nitrophenyl chloroformate (1.1 eq.) was added to it. The reaction was allowed to run under argon at room temperature overnight and 1.1 eq. of 4-amino butyric acid allyl ester was added to it. The reaction was stirred for 24 hours and continuous monitoring of TLC indicated no more conversion of starting material to the protected product. The solvent was evaporated and the protected carbamate dimer was purified (135 mg) on silica gel column (10% EtOAc:DCM).
[0063] The protected carbamate dimer was dissolved in 5 ml of dichloromethane and 0.05 eq. of phenyl silane and 0.005 eq. of Tetrakis triphenyl phosphine palladium was added to it. The reaction was allowed to run at room temperature for 3 hours at which time 1 ml of methanol was added and stirred for another 10 minutes.
[0064] The solvent was evaporated and the residue was chromatographed on silica gel column and eluted with 30:70 ethyl acetate:dichloromethane with polarity increasing to 20:80 ethyl acetate:methanol. Similar fractions were combined to give one major fraction having the desired product (78 mg), with spectral data consistent with structure 11.
[0065] 1 H-NMR in CDCl 3 at 400 MHz: δ 5.40 and 5.34 (1H each, s each, H-5 and H-5′); 5.27 (2H, s, H-12 and H-12′); 4.76 (1H, br dd, J=2.4 Hz, H-17); 3.88 and 3.53 (2H each, br dd each, J=4.4 Hz, H-16 and H-16′); 3.18 (2H, q, J=6.4 Hz, H-19); 2.57, (2H, br s, H-11 and H-11′); 2.35 and 1.99 (2H each, m each, H-3 and H-3′); 2.29 (2H, m, H-21); 1.80 and 1.58 (2H each, m each, H-2 and H-2′); 1.78 (6H, m, H-9 and H-9′, and H-20); 1.70 and 1.40 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.38 (6H, s, Me-15 and Me-15′); 1.20 (2H, m, H-1 and H-1′); 0.92-0.84 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0066] 13 C-NMR in CDCl 3 at 100 MHz: δ 177.16 (s, C-22); 155.90 (s, C-18); 104.16 and 104.08 (s, C-4 and C-4′); 102.62 and 102.18 (d, C-12 and C-12′); 87.93 and 87.87 (d, C-5 and C-5′); 81.04 and 81.00 (s, C-6 and C-6′); 71.90 (d, C-17); 67.71 and 66.63 (t, C-16 and C-16′); 52.51 (d, C-1 and C-1′); 44.36 (d, C-7 and C-7′); 40.33 (t, C-19); 37.41 and 37.38 (d, C-10 and C-10′); 36.40 (t, C-3 and C-3′); 34.60 (t, C-9 and C-9′); 31.15 (t, C-21); 30.80 (d, C-11 and C-11′); 26.05 (q, C-15 and C-15′); 24.93 (t, C-20); 24.62 (t, C-2 and C-2′); 24.40 (t, C-8 and C-8′); 20.34 and 20.30 (q, C-14 and C-14′); 12.90 (q, C-13 and C-13′).
[0067] HREIMS: (m/z) 776.3936 [M+Na], (calcd. for C 38 H 59 NO 4 , 753.3936).
Example 7
Preparation of the Benzyl Amine of the β,β-Dihydroartemisinin Dimer with Dihydroxy Acetone (12)
[0068] β,β-Dihydroartemisinin dimer with dihydroxy acetone (4) (15 mg, 0.02 mmol) was dissolved in 1.5 ml of dichloroethane and benzyl amine (1 eq) was added to it. Sodium triacetoxy borohydride (1 eq) and AcOH (1 eq) were added and the reaction was allowed to run under argon at room temperature for 72 hours with continuous monitoring with TLC. 1N NaOH was added to quench the reaction and the mixture shaken with ether (3×10 ml). The organic layer was dried over anhydrous sodium sulphate and evaporated to dryness.
[0069] The residue was chromatographed on silica gel column and eluted with ethyl acetate with polarity increasing to 30:70 ethyl acetate:dichloromethane. Fractions were collected and similar fractions were combined to give one major fraction having the desired product (7.9 mg), with spectral data consistent with structure 12.
[0070] 1 H-NMR in CDCl 3 at 400 MHz: δ 7.33 (3H, s, H-20, H-21 and H-23); 7.32 (1H, s, H-24); 7.27 (1H, s, H-22); 5.40 and 5.39 (1H each, s each, H-5 and H-5′); 4.82 (2H, br t, J=4.8 Hz, H-12 and H-12′); 3.86 (2H, d, J=2.4 Hz, H-18); 3.95 and 3.45 (2H each, m and dd, J=4.6 Hz, H-16 and H-16′); 3.01 (1H, m, H-17); 2.66, (2H, m, H-11 and H-11′); 2.38 and 2.06 (2H each, ddd and m, J=3.6 Hz, H-3 and H-3′); 1.89 (4H, m, H-9 and H-9′); 1.88 and 1.62 (2H each, m each, H-2 and H-2′); 1.74 and 1.48 (4H each, m each, H-7 and H-7′, H-8 and H-8′, and H-10 and H-10′); 1.45 (6H, s, Me-15 and Me-15′); 1.28 (2H, m, H-1 and H-1′); 0.96-0.91 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0071] 13 C-NMR in CDCl 3 at 100 MHz: δ 140.57 (s, C-19); 128.96 (d, C-21 and C-23); 128.38 (d, C-20 and C-24); 126.93 (d, C-22); 104.05 (s, C-4 and C-4′); 102.61 and 102.38 (d, C-12 and C-12′); 87.91 (d, C-5 and C-5′); 81.02 (s, C-6 and C-6′); 68.17 (t, C-16 and C-16′); 56.61 (d, C-17); 52.59 (d, C-1 and C-1′); 51.50 (t, C-18); 44.41 and 44.39 (d, C-7 and C-7′); 37.37 and 37.34 (d, C-1 and C-10′); 36.51 (t, C-3 and C-3′); 34.60 (t, C-9 and C-9′); 30.98 and 30.94 (d, C-11 and C-11′); 26.20 (q, C-15 and C-15′); 24.60 (t, C-2 and C-2′); 24.65 (t, C-8 and C-8′); 20.36 (q, C-14 and C-14′); 13.13 and 13.11 (q, C-13 and C-13′).
[0072] HREIMS: (m/z) 714.5016 [M+H], 736.4081 [M+Na], (calcd. for C 40 H 59 NO 10 , 713.4139).
Example 8
Preparation of the Amino Hexanoic Acid Derivative of the β,β-Dihydroartemisinin Dimer with Dihydroxy Acetone (13)
[0073] β,β-Dihydroartemisinin dimer with dihydroxy acetone (4) (15 mg, 0.02 mmol) was dissolved in 1.5 ml of THF and 6-amino hexanoic acid (1 eq) was added. Sodium triacetoxy borohydride (1 eq) and AcOH (1 eq) were then added and the reaction was allowed to run under argon at room temperature for 4 hours with continuous monitoring on TLC. 1N NaOH was added to quench the reaction and then the mixture shaken with ether (3×10 ml) and DCM (3×10 ml). The organic layers were combined and dried over anhydrous sodium sulphate and evaporated to dryness.
[0074] The residue was chromatographed on silica gel column and eluted with ethyl acetate with polarity increasing to 30:70 methanol:ethyl acetate. Fractions were collected and similar fractions were combined to give one major fraction having the desired product (7.3 mg), with spectral data consistent with structure 13.
[0075] 1 H-NMR in CDCl 3 at 400 MHz: δ 5.41 and 5.40 (1H each, s each, H-5 and H-5′); 4.84 (2H, s, H-12 and H-12′); 4.15 and 3.75 (2H each, m each, H-16 and H-16′); 3.42 (1H, m, H-17); 2.67, (2H, m, H-11 and H-11′); 2.35 (4H, m, H-3 and H-3′); 1.88 and 1.50 (2H each, m each, H-2 and H-2′); 1.78 (4H, br s, H-8 and H-8′); 1.42 (6H, s, Me-15 and Me-15′); 1.27 (2H, m, H-1 and H-1′); 0.97-0.92 (12H, Me-13 and Me-13′, and Me-14 and Me-14′).
[0076] 13 C-NMR in CDCl 3 at 100 MHz: δ 104.16 (s, C-4 and C-4′); 103.02 and 102.63 (d, C-12 and C-12′); 88.02 and 87.96 (d, C-5 and C-5′); 80.90 (s, C-6 and C-6′); 65.84 and 65.73 (t, C-16 and C-16′); 56.80 (d, C-17); 52.51 (d, C-1 and C-1′); 44.16 (t, C-18); 44.23 (d, C-7 and C-7′); 37.24 and 37.19 (d, C-10 and C-10′); 36.46 (t, C-3 and C-3′); 34.59 (t, C-9 and C-9′); 30.78 and 30.71 (d, C-11 and C-11′); 26.05 (q, C-15 and C-15′); 24.56 (t, C-2 and C-2′); 20.36 and 20.39 (q, C-14 and C-14′); 13.03 (q, C-13 and C-13′).
[0077] HREIMS: (m/z) 738.4469 [M+H], 760.4274 [M+Na], (calcd. for C 39 H 63 NO 12 , 737.4350).
Example 9
Anticancer Activity of Compounds 6-13
[0078] The anticancer activity of compounds 6-13 was evaluated at the National Center for Natural Products Research (NCNPR) against the following cell lines:
[0000] SK-MEL (Human Malignant Melanoma); KB (Human Epidermal Carcinoma, oral); BT 549 (Breast Ductal Carcinoma); and SK-OV3 (Human Ovary Carcinoma). Cytotoxicity was evaluated in two cell lines, namely Vero cells (Monkey Kidney Fibroblast) and LLC-PK1 (Pig Kidney Epithelial).
[0079] The results of the testing are summarized in table 1.
Example 10
Antimalarial Activity of Compounds 6-11
[0080] The antimalarial activity of compounds 6-11 was evaluated on the antimalarial screen carried out at the NCNPR. The compounds were tested against two stains of the malaria parasite namely the D6 clone and the W2 clone of Plasmodium folciparum , with cytotoxicity evaluated using Vero cells. The activities of these compounds are presented in table 2.
Example 11
Antileishmanial Activity of Compounds 6-13
[0081] The activity of compounds 6-13 against the leishmanial parasite was evaluated at the NCNPR. The activity of these compounds are shown in table 3.
LITERATURE CITED
[0000]
1 American Cancer Society, Statistics for 2001. (http://www.cancer.org/downloads/STT/F&F2001.pdft)
2. Cragg, G. M., Newman, D. J., Snader, K. M.: Natural products in drug discovery and development. J. Nat. Prod., 60:52-60 (1997).
3. Shu Y. Z.: Recent natural products based drug development: a pharmaceutical industry perspective. J. Nat. Prod., 61:1053-1071 (1998).
4. Cragg, G. M., Newman, D. J., Weiss, R. B.; Coral reefs, forests, and thermal vents: the worldwide exploration of nature for novel antitumor agents. Seminar Oncol 24:156-163 (1997).
5. Clark, A. M.: Natural products as a resource for new drugs. Pharmaceut Res 13:1133-1141 (1996).
6. Report of the Coordinating Group for Research on the Structure of Qing Hao Su. K'O Hsueh T'Ung Pao 22, 142 (1977); Chem. Abstr. 87, 98788g (1977).
7. Beekman, A. C., Barentsen, A. R. W., Woerdengag, H. J., Van Uden, W., Pras, N., El-Feraly, F. S., and Galal, A. M. Stereochemistry-dependent cytotoxicity of some artemisinin derivatives; J. Nat. Prod., 60: 325 (1997).
8. Zheng, G. Q; Cytotoxic terpenoids and flavonoids from Artemisia annua, Planta Medica, 60 (1): 54-7 (1994).
9. Woerdenbag, H. J., Moskal, T. A., Pras, N., Malingre, T. M., Kampinga, H. H., Konings, A. W. T., and El-Feraly, F. S., Cytotoxicity of artemisinin-related endoperoxides to Ehrlich ascites tumor cells, J. Nat. Prod, 56: 84a (1993).
10. Beekman, A. C., Woerdenbag, H. J., Kampigna, H. H., and Konings, A. W. T.; Sterochemistry-dependent cytotoxicity of some artemisinin derivatives, Phytother. Res., 10, 140 (1996).
11. Posner, G. H., et al; Trioxane Dimers Have Potent Anti-malarial, Anti-proliferative, and Anti-tumor Activities In Vitro, Bioorganic and Med. Chem., 5:1257-65 (1997).
12. Posner, G. H., Ploypradith, P., Parker, M. H., O'Dowd, H., Woo, S.-H., Northrop, J., Krasavin, M., Dolan, P., Kensler, T. W., Xie, S., and Shapiro, T. A.; Antimalarial, Anti-proliferative, and Anti-tumor Activities of Artemisinin-Derived, Chemically Robust, Trioxane Dimers, J. Med. Chem., 42, 4275-80 (1999).
13. Zhang and Darbie, U.S. Pat. No. 5,677,468 (1997).
14. Zhang and Darbie, U.S. Pat. No. 5,856,351 (1999).
15. ElSohly, M. A., Ross, S. A., and Galal, A. M.; U.S. Pat. No. 6,790,863 B2 (2004).
16. ElSohly, H. N., Croom, E. M., El-Feraly, F. S., and El-Sheri, M. M., J. Nat. Prod., 53(6):1560-4 (1990).
17. ElSohly, H. N, and El-Feraly, F. S., U.S. Pat. No. 4,952,603 (1990).
18. Lin, A. J., Klyman, D. L., and Milhous, W. K., J. Med. Chem. 30, 2147 (1987).
19. El-Feraly, F. S., and Hufford, C. D., J. Org. Chem., 47, 1527 (1982).
20. El-Feraly, F. S., Ayalp, A., Al-Yahia, M. A., McPhail, D. R. and McPhail, A. T., J. Nat. Prod., 53 (1), 66-71 (1990).
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This invention comprises compositions containing dihydroartemisinin- and dihydroartemisitene-dimers with activity as anticancer or anticancer metastasis agents and anti-protozal, including anti-malarial and anti-leishmanial properties. This invention also describes methods of preparation of these compositions and methods of use of such compositions for the treatment of cancer or prevention of cancer metastasis, and protozoal infections, including malaria, or leishmaniasis. The compounds of this invention represent a potential new class of anti-tumor or anti-metastasis agents, one that has shown promising activity against solid tumors.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority of German Patent Application No. P 199 10 438.7, filed Mar. 10, 1999, which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
The invention relates to an infinitely-variable pulley drive having two pulleys, respectively disposed on the drive shaft and the output shaft, with a transmission element that circulates between the pulleys, and pressing forces for setting and maintaining the gear transmission being generated by a pressure medium on the drive and output pulleys. A sensor is disposed on the drive shaft that receives torque and generates the pressing forces as a function of the load. The pressure medium flows to the sensor with the output-side pressure and the sensor generates a torque-dependent pressure through a torque-dependent relative movement between at least two valve parts of a valve, thereby supplying the necessary load-dependent pressing force. The sensor operates as a torque-dependent pressing device having oppositely-located pressing cam tracks and, between the cam tracks roller bodies are inserted. The first ring of the device, which has one half of the pressing cam tracks, is fixedly secured to the shaft to co-rotate therewith. The other half of the pressing cam tracks is disposed on a second ring, which is disposed to be displaced axially on the shaft, between the first ring and a cylinder that is fixed to the shaft. The second ring and the cylinder form a first cylinder-piston aggregate that is acted upon by the output-side pressure medium. The second ring and the shaft form a valve for the return flow of the pressure medium from the first cylinder-piston aggregate via a shaft bore, with which the chamber between the first and second rings is connected. A chamber between the first and second rings is closed by a cylinder jacket that radially adjoins one of the rings on the outside, is oriented toward the other ring and is coaxial to the drive shaft, the jacket forming a second cylinder-piston aggregate with the other ring.
In such pulley drives, the arrangement is typically such that one of the pulleys can be axially displaced on each shaft, but is connected, at least indirectly, to co-rotate with the shaft, and is embodied as a pressure cylinder of a piston fixed to the shaft, to which the pressure medium is metered by a rectangular control plunger for setting and maintaining the gear transmission, the plunger being, for example, connected via a control lever to one of the axially-displaceable pulleys, while the two other pulleys are fixed axially and against relative rotation with respect to the shaft.
A pulley gear of the type mentioned at the outset is known from, for example, German Patent Document No. 28 28 347. This document also discloses a design in which a torque sensor is seated on the drive shaft of the gear and is charged by the pressure-medium pressure present in an output-side cylinder-piston aggregate.
The fact that the chamber between the first and second sensor rings is closed to the outside in the known gear to form a second cylinder-piston aggregate, as described in detail in the cited document, serves to form another chamber outside of that chamber in order to damp the movement of the second, axially-displaceable ring in one of the two directions of movement with the aid of the pressure-medium volume located in this chamber.
An aspect of the nature of pulley gears of the present type is that, with respect to a particular drive torque, the necessary pressing force between the output-side pulleys and the transmission element circulating between them depends on whether the transmission position of the gear is set at slow or fast output ratio settings. At slow output ratios (i.e., a slower rotation speed on the output side than on the input side) a higher pressing force is required than when the gear is set at faster output ratios. The same is true when, for example, in an application in a motor vehicle, the total overall speed of the gear increases, which also requires a corresponding increase in the level of the pressing forces.
With these circumstances in mind, in gears of the present type, in which the pressing force between the pulleys and the transmission element is determined by a torque sensor, it is desirable to set the output-side pressing force at a higher value when the transmission position is set for a slow output ratio, or when the transmission is operating at a higher total overall gear speed. It is also desirable to avoid overly-high pressing forces when the transmission is set for fast output ratio operation or operating with a low total overall gear speed.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an infinitely-variable pulley gear that avoids the occurrence of overly-high pressing forces when the transmission is set for fast output ratios or operating at a low total overall speed, that also provides a sufficiently high pressing force for transmission positions with a slow output ratio or operation at a high total gear speed.
This object and others to become apparent as the application progresses, are accomplished by the invention, according to which, briefly stated, the surface which is exposed to the pressure medium and which forms part of the second ring has, at its side having the cam track, a greater area than at its side oriented toward the first cylinder-piston aggregate.
This feature according to the invention utilizes the effect exerted by centrifugal force on the pressure medium located in the second cylinder-piston aggregate. According to this effect, at high rotational speeds the pressure medium is exposed to a correspondingly higher centrifugal force, and exerts a correspondingly higher pressure on the axially displaceable, second ring. If the pressure-charged surface of the second ring on the side facing the second cylinder-piston aggregate is larger than on the side facing the first cylinder-piston aggregate, at high output-side speeds at the second ring an additional control variable results at the second ring, which likewise results in an additional throttling effect of the torque sensor, and thus a correspondingly higher pressing force on the output side than at low speeds, without the gear being exposed to an overly high pressure in transmission positions with fast output ratios. The same applies for the above-discussed total gear speed.
The features of the invention, which can employ simple, automatically-acting means, thus avoid application of too much pressure, so the gear operates extremely cost-effectively and reliably.
A design that has proven useful according to the invention is for the outside or major diameter of the second cylinder-piston aggregate to be larger than that of the first cylinder-piston aggregate, with an identical, common inside or minor diameter.
The subject of the invention can be readily implemented in different torque sensor designs, depending on how the drive-side torque is to be introduced because of further structural requirements. For example, the shaft may be divided into segments between the first and second rings, and the torque may be introduced into the gear by way of the shaft part supporting the first ring. It is also possible, however, to introduce the torque into the gear by way of the second ring, in which case the drive shaft is not segmented. Teeth provided at the outer circumference of the second ring, for example, for transmitting force can permit the introduction of the torque via the second ring. Finally, to provide a space-saving design, it can be advantageous for the cylinder for the first cylinder-piston aggregate to be formed by the adjacent pulley that is supported in an axially fixed manner, and fixed against relative rotation with respect to the drive shaft, so that providing a special component for the cylinder is not necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a manually settable pulley gear, partly in section, with torque sensors on both gear sides to accommodate torque reversal.
FIG. 2 shows a first embodiment of a torque sensor, in an axial half-section.
FIG. 3 shows a cutout, sectional view according to the sectional line III—III in FIG. 2 .
FIG. 4 shows a second embodiment of a torque sensor in an axial half-section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to FIG. 1, a pulley gear has a drive shaft 1 carrying a pulley composed of a pair of conical pulley disks 4 , 6 and an output shaft 2 carrying a pulley composed of a pair of conical pulley disks 3 , 5 . The pulley disks 3 and 4 are affixed to the respective shafts 1 and 2 , while the pulley disks 5 and 6 are axially displaceable on, but torque-transmittingly connected to, the respective shafts 1 and 2 . The pulley disks 5 and 6 form a respective cylinder 7 , 8 , in which a piston 9 that is fixed axially and against relative rotation to the shafts 1 , 2 is disposed. A transmission element 10 circulates between the pulleys 3 through 6 .
To maintain or change the gear transmission, a pressure medium drawn by a pressure-medium pump 14 from an oil reservoir 15 is metered to the chambers of the cylinders 7 and 8 by a rectangular control plunger 11 via lines 12 and 13 . A free end of a control lever 16 , which is connected to the plunger 17 of the rectangular control plunger 11 , extends into a groove 18 of the cylinder 7 , while its other free end is manually operable.
If the gear is tending to deviate from the manually-set transmission position, it does so via the control lever 16 and its extension into the groove 18 for displacing the control plunger 17 , which assures a resetting or maintenance of the manually-set gear transmission in a known manner. The same is true when the transmission position is manually changed at the control lever 16 until the set gear transmission has been attained, and the new transmission status has been established.
The operating mode of the rectangular control plunger 11 in the described example is such that a higher pressure is made available to the drive side via the line 12 , while the return flow of the pressure medium conducted to the output side is throttled proportionally to the load. This purpose is served by two torque sensors 19 and 20 , each having a throttle valve, and of which only the sensor disposed on the drive side is active for the output side, due to a reversing switch 21 .
In the present example, the shaft 1 is a drive shaft. Accordingly, the pressure medium is metered directly to the cylinder 7 , due to the position of the plunger 17 , by the pump 14 via the line 12 , corresponding directly to the setting of the transmission control lever 16 . In contrast, in the illustrated equilibrium position, the intake for the pressure medium into the line 13 is opened little, or hardly at all. On the other hand, the pressure medium reaching the torque sensor 19 from there via the outside edge of the plunger 17 and the line 22 , 23 , is affected by the valve position of the sensor 19 , and flows for example via the line 24 for chain lubrication.
This function with the described parts suffices when no change between the drive and output shafts is anticipated in a gear. If this is the case, however, a torque sensor 20 is also provided on the shaft 2 for the event that the shaft 2 is a drive shaft and the shaft 1 is an output shaft. In this case, to activate the torque sensor 20 via the lines 22 and 25 , the pressure present in the cylinder 8 on the drive side now reaches the reversing switch 21 via a line 26 , where it adjusts the piston 27 upward, relative to the representation in FIG. 1 . If the shaft 1 is, again, a drive shaft, the drive-side pressure travels via the line 28 to the piston 27 , and restores it to the position shown in the drawing.
The torque sensors 19 , 20 according to FIG. 1 can be embodied in the manner illustrated in detail in FIG. 2, where only one half of the torque sensor and the associated shaft arrangement is shown, in an axial section, for the sake of simplicity.
As can be seen in detail in FIG. 2, the respective drive shaft is divided into segments 30 , 31 , the shaft parts being connected to one another by the torque sensors 19 and 20 , each having a valve. A first ring 32 is seated on the shaft segment 30 such that it co-rotates with the shaft segment 30 , and is fixed against an axial movement to the left. A second ring 33 is disposed so as to be fixed against relative rotation with the shaft segment 31 , but can be axially displaced. At their end faces facing one another, the rings 32 and 33 have cam tracks that are known, and are therefore not described again in detail; they are formed by V-shaped notches 34 , 35 , in both the radial and circumferential directions (see also FIG. 3 ), between which roller bodies 36 are inserted for transmitting torque.
A cylinder 37 , in which the ring 33 is axially displaceable as a piston, is also secured, at least axially, to the shaft segment 31 . The pressure medium coming from the line 23 or 25 with the pressure present on the respective output side of the gear flows to the cylinder chamber 38 formed between the cylinder 37 and the ring 33 via the bore 39 of the shaft segment 31 and an adjoining, radial bore 40 , and exits the chamber again via the annular groove 41 , an adjoining a radial bore 42 , that extends to an axial bore 43 and the conduit 44 of the shaft segment 30 . A flange 45 extending into the cylinder chamber 38 and the annular groove 41 together form the throttle valve.
The torque sensors 19 and 20 described above operate as follows:
Corresponding to the torque to be transmitted between the shaft segments 30 , 31 forming the drive shaft 1 or 2 , the rings 32 and 33 endeavor to rotate opposite one another in the circumferential direction, which causes the ring 33 to be displaced more or less to the right, with respect to FIG. 2 , due to the V-shaped notches 34 , 35 and the interposed roller bodies 36 . This causes the flange 45 to close the annular groove 41 , so the pressure medium flowing into the cylinder chamber 38 via 23 or 25 and 39 and 40 flows off more or less until the pressure-medium pressure present in the cylinder chamber 38 maintains the equilibrium of the axial force at the ring 33 , which force is exerted from the other side due to the V-shaped notches 34 , 35 and the roller bodies 36 . Thus, however, the pressure-medium pressure that is required in the pressure chamber of the respective output-side cylinder 8 or 7 also is present in the cylinder chamber 38 , because the cylinder chamber 38 is connected to this pressure chamber via the bore 39 .
As explained at the outset, in the transmission setting of the gear according to FIG. 1 at slow output ratios, or at a high total gear speed on the output side of the gear—with respect to a specific torque to be transmitted—a higher pressing force is necessary between the pulleys and the transmission element 10 than is required in the transmission position of the gear at fast output ratios or at low total gear speeds. To take this into account, one of the rings, in the present case the ring 33 , is provided with a cylinder jacket 46 , which is coaxial to the shaft segments 30 , 31 and extends axially beyond the other ring, in this case the ring 32 , the ring 32 being disposed in the manner of a piston inside the jacket. The chamber 47 formed between the rings 32 , 33 is embodied as a closed pressure chamber, to which the pressure medium flowing off along the bores 43 , 44 flows via the separating seam 48 between the shaft segments 30 , 31 due to the effect of centrifugal force.
The arrangement is also such that the surface 49 , which is charged with the pressure medium and by which the ring 33 faces the chamber 47 , is larger than the surface 50 , which is also charged with the pressure medium and by which the ring 33 faces the cylinder chamber 38 . As the speed of the torque sensor 19 or 20 increases, a greater axial force is exerted on the ring 33 from the sides of the chamber 47 than from the sides of the cylinder chamber 38 ; consequently, the ring 33 is adjusted accordingly to the right, in reference to FIG. 2, and an additional throttling effect occurs between the flange 45 and the annular groove 41 .
As the drive-side speed increases, as in the case of an adjustment of the gear transmission to a slow output ratio or an increase in the total overall gear speed, the drive-side torque sensor effects an additional throttling for the return flow of the pressure medium having the pressure dominating on the output side of the gear, and therefore causes an increase in the pressure-medium pressure present on the output side, and an increase in the output-side pressing force between the pulleys and the transmission element 10 . Taken alone, this increase in the output-side pressing force would force the gear out of the desired transmission position. This is prevented, however, by the extension of the control lever 16 into the circumferential groove 18 , and its connection to the plunger 17 , because a tendency of the gear to leave the desired transmission position is counteracted by the associated position of the plunger. In the present case, the aforementioned increase in the output-side pressing force via the plunger 17 also leads to a corresponding increase in the drive-side pressure-medium pressure, and therefore the drive-side pressing force, until the gear is again located in the equilibrium state in the desired transmission position.
The design according to FIG. 2 is intended to introduce the torque directly and axially into the gear via the drive shaft embodied by two segments 30 , 31 . For specific structural reasons, however, it may also be desirable to work with an undivided drive shaft, or to introduce the torque into the drive shaft radially.
FIG. 4 illustrates a design for the torque sensor that permits this option. Here, the torque sensor seated on the undivided drive shaft 1 or 2 again has a first ring 51 , which is fixed in the axial and circumferential directions, and a second ring 52 , which is displaceable opposite the first ring, both in the axial and circumferential directions, and otherwise corresponds in its structural embodiment, including the cylinder chamber 38 and the pressure chamber 47 between the rings, to the design shown in FIG. 2; therefore, the explanations given above are not repeated here—refer to the reference characters given in the above description.
The return flow of the pressure medium from the cylinder chamber 38 is effected here by the modified construction, starting from a radial blind bore 53 , through a connecting channel 54 and the axial inside groove 55 of the ring 51 , which is connected via a feather key 56 so as to co-rotate with the shaft 1 , 2 . Once outside of the ring 51 , the pressure medium travels along teeth 57 into a free space; a drive bell 58 engages the ring 52 via these teeth, with a corresponding engaging teeth, the drive bell 58 being seated to rotate on the shaft 1 , 2 , but supported against axial movement.
Instead of the drive bell 58 , a spur gear, for example, could engage the teeth 57 of the ring 52 in the same manner.
A further difference between the design according to FIG. 4 and the design according to FIG. 2 is that, in FIG. 4, the cylinder for the pressure chamber 38 is formed directly by the pulley disk 3 or 4 adjacent to the torque sensor, that is, the pulley of the respective drive-side disk set that is fixed in the axial and circumferential directions, which eliminates the requirement of a separate cylinder for the cylinder chamber 38 . Of course, the cylinder 37 according to FIG. 2 can also be replaced by a correspondingly-designed pulley that is fixed to the shaft, in the manner described in conjunction with FIG. 4 .
The operating mode of the torque sensor explained in conjunction with FIG. 4 otherwise corresponds to the operating mode of the torque sensor according to FIG. 2; refer to those explanations.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A pulley gear for an infinitely-variable pulley drive has one pulley disposed on a drive shaft and another pulley disposed on an output shaft, and a transmission element circulating between the pulleys. An output side pressing force is applied to the output side pulley by a pressure medium and a drive side pressing force is applied to the drive side pulley by the pressure medium. The pulley gear has a valve that generates a torque-dependent pressure through the torque-dependent relative movement of a first ring, a jacket, and a second ring, thereby providing a load-dependent pressing force. A cylinder and the second ring form a first cylinder-piston aggregate, and the jacket and first and second rings form a second cylinder-piston aggregate. The first ring has a first cam track thereon and the second ring has a second cam track. The surface of the second ring which is exposed to the pressure medium and which has the cam tracks has a greater area than an area of the surface of the second ring exposed to the pressure medium and oriented towards the first cylinder-piston aggregate.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Nonprovisional patent application Ser. No. 10/944,287, filed Oct. 21, 2008 (now U.S. Pat. No. 7,440,992) which claims priority from co-pending U.S. Provisional Patent Application No. 60/503,759 filed Sep. 16, 2003 entitled “Self-Contained, Mobile, Autonomous Software Agent”, which is hereby incorporated by reference, as if set forth in full in this document, for all purposes.
BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention is generally related to distributed computing environments and in particular to secure operation of agents accessing services as components of the distributed computing environment.
2. The Prior State of the Art
Distributed computing environments allow for dispersal of tasks performed by an application. As distributed computing environments become more prevalent and well understood, many monolithic programming efforts are being replaced with modular computing efforts.
In a modular view of the computing, modules have their own identities, which are separate from descriptive attributes. A module can be a collection of programmable interfaces. Modules typically have well-defined programmable interfaces at both the source code level and the run-time executable code level. The interfaces are uniquely identified by name or some unique key value, often called a globally unique identifier (GUID). The uniqueness of a module name provides a mechanism such that the module's visibility within a containing process, application, archive, or another module is clear. For example, two spell checking processes may exist on a computing device; however without a way to distinguish between the two, an application could make use of the one of the spell checkers with unpredictable results.
One driving factor in modular-based development and run-time systems has been the need to control and reduce the increased technical complexity of software development. Goals of modular-based software development include producing software that is fully scalable to small or large computing environments and producing it faster than is possible with monolithic programming.
A typical application today using conventional monolithic programming might have an event-driven graphical user interface (GUI), network interfaces to both a local area network and the Internet, and include a multi-tiered architecture for use within client-server environments. In contrast, modules allow for a level of abstraction at design time when modeling applications and systems, so that systems can then be assembled at run-time with modules viewed as “black boxes” resulting in a known and understood behavior.
Modules that have been well tested and perform well can be used within an application with a level of trust that they will perform as expected. Modules that are buggy or do not perform well can be refactored and worked on in isolation from more stable modules. While not altogether eliminating the technical complexity of software development, applications and systems built using modules can be assembled more quickly and offer a level of trust that could not be realized in a monolithic architecture.
Several well-known frameworks support module-based computing, including Microsoft's COM, COM+, and .Net frameworks, Sun's JavaBeans framework, and OMG's CORBA environment. Using these frameworks, a developer can build modules that interact with other modules on local machines and across networks. The most common method of module interaction and communication in these environments is through a remote procedure call (RPC) mechanism, where a remote module's interface is made to be seen the same as calling a module's internal interface. Although the level of interoperability provided by RPC mechanisms between heterogeneous modules is limited, current frameworks do offer a good way to build module-based applications and systems. The frameworks also do a fair job of hiding the complexity of using modules that are distributed across the network, particularly within a local, secured network, but they present more of a challenge with unsecured networks such as the Internet.
An agent is a modular software component that has a level of autonomous behavior and acts on behalf of an application or process often referred to as the agent's “client”. An agent is designed to carry out one or more specific functions for its client.
Mobile software agents are agents that can move from one environment to another environment, with their execution in the one environment able to continue in the other environment. Mobile agents can solve problems with network bandwidth utilization. If a computing process needs to sift through a large volume of remote data, having the computing process run on a local computer and access the data over a network would use considerable network bandwidth. A more bandwidth efficient method would be to have the computing process provide or invoke an agent to move near the data and perform its operations locally.
Mobile agents are also useful for overcoming problems of intermittent network connectivity. For example, if a local computer is executing a long-running process that requires processing data across the network and the local computer can become disconnected from the network, the process may fail. A better solution is to allow an agent to move near the data and perform its processing operations, then have the agent (or its data) return to the local computer when the local computer is ready to receive the results of the agent's operations.
Agents using complex programming logic can sometimes exhibit seemingly intelligent behavior. These agents are often referred to as “intelligent agents”. Some intelligent agents perform a directed sequence of actions to achieve a processing goal. Some use a knowledge base. Some use artificial intelligence (AI) methods, such as neural networks to provide problem solving processing.
IBM's recently open sourced Aglets framework allows for the building and deployment of Java-based mobile agents, but their uses are limited and do not provide the container control or interaction that might be needed.
Jade is a Java-based development environment that claims Foundation for Intelligent Physical Agents (FIPA) compliance. FIPA is a non-profit organization that promotes and provides specification for the interoperability of agents. Jade code, and similar approaches, has a default mode of running without security. A security manager can be used to protect machine resources, but this must be used throughout a system to ensure full security.
A service, as used herein, is a software component that provides computer processing through a clearly defined interface. For example, an application using the information provided by the clearly defined interface could execute a “stock quote” service, and a “weather” service, possibly provided by different vendors, and combine the results into an application that provides a graphical user interface (GUI) to show how weather affects stocks. This application could provide, as an adjunct to the GUI, a service that would supply the results to other applications in a raw form as data.
A service-oriented architecture (SOA) is used to describe applications and systems built primarily using services that are made available. An example of a service is a web service. Web services might interoperate with other services and applications using a wire-level standard protocol such as the Simple Object Access Protocol (SOAP) that uses Extensible Markup Language (XML) to describe a service interface and data elements that will be sent by the invoker of the web service. SOAP is also the protocol of the returned results.
Unlike the more common Remote Procedure Call (RPC), web services use a self-describing interface to communicate. The interface fully describes the method by which the service is accessed. The contents of a SOAP message include the service interface description and data. By using self-describing interfaces and a wire-level protocol like SOAP, heterogeneous components can communicate. For example, a C++ based module can interoperate with a JavaScript web service.
The scripting of various service processes is called orchestration or workflow. Microsoft's BizTalk Server is a well-known product that provides for the orchestration of services and XML messages. There is also work being done to provide standard specifications for how web services are orchestrated. For example, Business Process Execution Language for Web Services (BPEL4WS) is one proposed standard. There are also proposed standards to address how a web service might provide support for transactional processing. Transactions are popular in database systems, where transactions provide a method to insure that a set of operations applied to the database either succeed in their entirety or fail in their entirety, leaving the database system in the same state as prior to the start of the transaction.
Some agent frameworks support services, such as web services (JADE is one example). The World Wide Web Consortium (W3C) is working on standards for agents to understand services and the functionality they offer, with Ontology Web Language for Services (OWL-S). While the generalized interaction of agents with services may make design of distributed computing environments easier, it comes at a price in terms of increased complexity and greater security concerns.
Some risks stem from the fact that untrusted (or only partially trusted) code is often allowed to execute on a machine often without the machine's owner's explicit knowledge, as is the case with mobile agents and downloaded services. The code that executes can have a cascade effect, where it modifies behavior or code that previously ran correctly but now runs poorly. An example is the application of a software patch or update that seemly installs acceptably, but after the update, the system is left operating poorly. Because the user is often unaware of the complex processing that takes place “under the covers” on the computing device, it can be extremely difficult to undo the changes caused by running mobile code.
Other security concerns with the use of mobile code are access to sensitive information that could be inadvertently used without the user's knowledge. The concerns described above are present with non-malicious code and the security concerns are greatly heightened if the mobile code has malicious intent.
One approach to maintaining security is the use of the “container” concept, wherein code runs on a platform that prevents the code from accessing other resources (software, hardware, etc.) of the platform other than through well-defined and controlled openings in the container. Examples are the Java Virtual Machine (JVM), the Java 2 Enterprise Edition (J2EE) Servlet Specification, and the Globus Toolkit. These typically require a developer to provide a significant amount of code to achieve the level of control and manageability required by automated applications.
What is needed is a system that can efficiently and securely manage service and agent interaction in a controlled environment.
SUMMARY AND OBJECTS OF THE INVENTION
The invention presented herein relates to a system and method in which the interaction between service components and agents that will make use of the service's computer processing are managed and controlled in a cell construct. The cells discover published services and load those services into the cells for later use by agents, or just make them available and load them as needed. By providing discrete processing, applications and other processes can match and negotiate for available services from those provided that best meet their application requirements and computing needs.
A service can be loaded into a cell by locating executable program code from a published service description and physically transferring the executable program code to the computer device or distributed devices operating the cell. Applications that deploy agents, as well as agents themselves, find services by looking up the services that a cell has published and made available. If an agent wants to use a service, then the agent makes a request to the cell providing the service and asks to be loaded, run and hooked up to the desired service. Agents can be loaded into the cell in the same manner as services, except the executable program code location might be contained in the agent's service request. If the cell accepts the agent's request, the agent is loaded and the service made available.
To provide a secure environment for the execution of service processes by agents, the cell does not provide a direct hook up between services and agents, but rather acts as a secure service interface to ensure that malicious or poorly performing services or agents do not harm the system or systems providing the environment. If the operations of a service or agent are found to cause system harm or instability, the cell can apply to a journal that captures all service and agent operations and return the system to a previous stable state.
A cell can act as a transaction manager for services that support transaction processing when agents choose to access those services using transaction support. Transactions allow a group of agent tasks to be executed as a single entity under control of the cell's transaction manager and either succeed or fail depending on the success or failure of all tasks in the group.
In some variations, cells form communities of cells. In some variations, cells can vote on which cell to first try a service or service upgrade (e.g., patch, new functionality) and monitor the results, thereby minimizing possible negative results on other cells.
The invention further provides for the operation of cell systems that exist behind firewalls. A bridging mechanism that uses a shared computer outside the firewall is polled by the cell system and messages, and possibly code, is forwarded to the correct cell or group of cells.
A further understanding of the nature and the advantages of the inventions disclosed herein may be realized by reference to the remaining portions of the specification and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a cell system including cells, cell service registry, agent service registry, service pool, and applications and agents according to one embodiment of the present invention.
FIG. 2 illustrates example data structures; FIG. 2A illustrates an example data structure representing a cell service description and FIG. 2B illustrates an example data structure representing an agent service description.
FIG. 3 is a schematic diagram of a proxy agent and the communication channels between the proxy agent and a cell based agent and service.
FIG. 4 illustrates an example data structure representing an agent invoke service description.
FIG. 5 is a schematic diagram illustrating a cell system and relationships between a system, cell, services, and agents.
FIG. 6 is a schematic diagram illustrating cell communication from behind firewalls.
FIG. 7 is a flow chart illustrating a cell start up process including loading services.
FIG. 8 is a flow chart illustrating a process of migration and using agents; FIG. 8 comprises FIGS. 8A and 8B ; FIG. 8A shows steps of an agent requesting to be migrated to a cell and creation of a proxy agent; FIG. 8B shows steps of the agent using a service by processing tasks.
FIG. 9 illustrates an example data structure representing a cell-to-cell interprocess communication description.
FIG. 10 is a block diagram illustrating an agent's use of a group of services by processing tasks under control of the cell's transaction processing manager.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will be described using the diagrams contained herein. The diagrams provide an illustration of the process flow, and possible embodiments, but should not be taken to be the extent and entirety of this invention.
Those skilled in the art will recognize that the present invention may be practiced in networked computing environments comprising many types of devices including personal computers, personal digital assistants, mobile phones, mini computers, main frames, dedicated embedded devices, and so on. The invention also may be practiced on a standalone computer device that has not been networked. The invention does not target a particular operating system or programming language. The invention could be implemented using C++, C#, Java and/or other programming languages.
As used herein, a cell is a structure that containerizes agents and service interactions with those agents. Typically, a cell executes in a platform of one or more computers and/or computing devices, wherein the cell is executed and controlled by the entity that controls the platform. A cell provides a computing boundary and that boundary can encompass one computing device, one portion or division of a computing device, or span multiple computing devices, such as a networked computer system, cluster, RAID, etc.
As an example, a home PC owner might have one or more cells running on their local PC. While not required, it can be assumed that the entity (the PC owner, in this example) that controls the platform does not fully trust the agents that might be executed within the cell and might not trust services that are provided by the cell to those agents. A cell can provide a set of constraints pertaining to a service or group of services, to be made available to an agent or a group of agents.
Constraints can be of one or more form, where generally constraints are provided to protect the equipment, operation and/or interests of the entity owning or controlling the platform and/or data and/or code with which a cell would operate. For example, a set of cells might be set up to perform actions deemed desirable by users of a network or computing devices coupled to the network and the entity operating or controlling the network (the network operator) could desire constraints that prevent users from accessing others' data without permission, from inadvertently or intentionally setting something in motion to interfere with the operation of the network, etc.
Examples of constraints include constraints that involve physical attributes of a computing device, such as memory, whereby the cell prevents services or agents from executing if the agent or service is found to require more memory than is available. Constraints could also involve communication with other cells. A service or agent deemed harmful could be flagged such that the cell (and other cells receiving input from the cell) would not load or execute the harmful service or agent. Cells can be physically based on some particular hardware or virtually situated and span multiple physical devices.
Cell System
FIG. 1 illustrates an environment in which a cell system might operate. A cell system 5 is shown as a box and it should be understood that various systems and components operate on a physical system, such as a computer having a processor, memory, I/O, networking interfaces, etc. However, as much of the present invention can operate on conventional hardware, some details of the underlying execution hardware are omitted here for clarity as the details of the present invention.
As shown in FIG. 1 , a cell system might comprise cell service provider-publishers and/or their corresponding computing systems, a cell service registry, cells, reporting systems, agent repositories, agent finders, agent service registries, a transaction manager and other components described herein. Each of these components might comprise software, firmware, logic and/or instructions running or stored on hardware devices (not all of which are explicitly shown herein) as needed to allow for the execution, storage, recall, etc. of such components.
A cell system 5 is shown in FIG. 1 comprising a provider-publisher 10 of cell services (or apparatus for providing and/or publishing), a cell service registry 16 , executable code for various services (shown as code 14 A- 14 C in the figure), a service finder 24 , and a cell 12 . The provider-publisher 10 makes services available by making an entry in cell service registry 16 that describes the service. Provider-publisher 10 could be a person or an automated process.
FIG. 2A illustrates an example data structure representing a cell service description, as might appear in cell service registry 16 . The entries each describe a service and contain a pointer to the actual service code 14 A- 14 C that will be executed by an agent described herein. The service code may or may not be contained in the cell service registry 16 . There can be any number of service entries in the cell service registry 16 and service code available. Each provider-publisher 10 preferably maintains the code pointed to in the service descriptions provided-published by it (shown in FIG. 2A ) and is responsible for publishing the availability of the services by making an entry into cell service registry 16 . The service description entries could exist in a number of computer systems. For example, the entries could exist in a local database 18 , in a database available over a network such as the Internet 22 or, in a simple case, as files in a locally available file system 20 .
Service finder 24 can locate the service descriptions in cell service registry 16 and load them into cell 12 . Service finder 24 can locate cell service registry 16 (or multiple service registries called out as 16 A and 16 B in FIG. 1 ) by using a multicast network request for the entries contained in the registry or by having the cell service registry 16 locations previously configured. For example, if the entries exist in a locally available file system 20 , then the path to a directory holding the service entries could be previously configured for use by the service finder 24 . The path might be a directory “C:/My Documents/Services” with files therein for each service description. Service finder 24 might periodically query cell service registry 16 to locate new service descriptions.
Service finder 24 can load all the service descriptions it finds in the service registry 16 into the cell system 5 . The loading could be done by making the service descriptions available in process memory of cell 12 or by making entries into a persistent storage area accessible to cell processes. Service finder 24 may exclude some services based on information contained in the service descriptions. For example, if the cell is executing on a computer device that does not match a service description's preferred environment values, service finder 24 might skip that service and not load its service description. Service finder 24 might also be aware of previous bad or poor performance of a service and skip loading it on that basis.
Services that are not programmed to run in a cell environment, or otherwise not meeting cell service interface requirements of the given cell environment can be run in the given cell environment using a service wrapper. A service wrapper provides, among possibly other features, a programming interface that acts as a front end to the otherwise noncompliant service. This is useful for supporting legacy services in a cell environment. The service wrapper might itself have an entry in cell service registry 16 .
Cell 12 executes on a computing platform (not shown) and is either controlled by the entity that owns or controls the computing platform or cell 12 executes in such a way that the computing platform is protected against actions of the cell. Cell 12 is shown in FIG. 1 comprising several elements, not all of which need be present in all implementations and cells might contain other elements not shown or described herein.
Cell 12 is shown comprising a service finder 24 , a service grabber 26 , instantiated services 28 , a service publishing object 32 , and agent service request handler 48 , an agent grabber 50 , instantiated agents 52 , a proxy interface 54 over which instantiated services 28 and instantiated agents 52 interface, and an inter-cell communication object 86 .
If a service is acceptable to cell finder 24 based on the values contained in the service description or previous knowledge of a service's performance, service publishing object 32 makes an agent service description entry into an agent service registry 34 . An example of the agent service description structure is shown in FIG. 2B . Service publishing object 32 can be implemented to parallel the manner that provider-publisher 10 publishes service availability to cell system 5 . Agent service registry 34 might be constructed from one or more of: a local database 36 , a remote database 38 accessed over a network such as the Internet, or storage on a local network 40 .
An application 42 (it should be understood that the term application may include agents in their own right, unless otherwise indicated) uses an agent service finder 44 to locate within agent service registry 34 a service or group of services that may satisfy an agent's goal or task. Agent service finder 44 could be embedded in application 42 itself or be provided as module for inclusion in application 42 . Agent service finder 44 , like service finder 24 , may use a multicast network request for the entries contained in agent service registry 34 or by having agent service registry 34 locations previously configured.
If an appropriate service is discovered (in this example, suppose cell 12 published service availability, then application 42 will make an agent service request to agent service request handler 48 requesting that a specified agent be loaded into cell 12 . Cell 12 can accept or deny the agent service request. If the agent service request is accepted, that fact is communicated to service grabber 26 and agent grabber 50 .
The service grabber 26 uses the information gathered by service finder 24 and fetches the executable code pointed to by the service descriptions, possibly by moving the code into the cell and instantiating one or more service 28 . Service grabber 26 might operate as a service negotiator. A service may be found acceptable to cell 12 through the values presented in the service description or by instantiating the service and negotiating with the service for loading into cell 12 .
In a particular embodiment, the executable code is not run immediately and is only instantiated when an agent requests to use the service, but this default can be overridden in that embodiment. An attribute in the service description can override the default implementation by including a flag that indicates that the service is to be pre-loaded when the service is requested, rather than waiting for an agent to actually need the service. Once a service is instantiated, it is ready for use by instantiated agents.
Agent grabber 50 grabs the accepted agent by moving the accepted agent's executable code 30 A from its location described in an agent invoke service description, such as that shown in FIG. 4 . Agent grabber 50 then instantiates the agent as instantiated agent 52 .
An instantiated agent 52 is preferably not hooked up directly to instantiated services 28 , but rather through the protective interface of proxy interface 54 . Using proxy interface 54 , an instantiated agent operates as if it is communicating with the requested instantiated services 28 directly, but the instantiated agent is actually communicating with the cell's proxy interface, which forwards requests and responses between the instantiated agent and the instantiated service. This allows for easier tracking and journaling, as explained below. It also allows for greater control over the environment.
Details of Selected Operations
FIG. 3 illustrates an operation of an application 342 in making a request 310 to a cell 300 to fetch/run an agent 308 . FIG. 4 illustrates one example of an agent invoke service description that is sent to cell 300 , either using a multicast network request sent to a group of cells or by having the cell locations previously configured. Other approaches can be used instead.
Cell 300 is shown comprising an instantiated service A 302 , an instantiated agent A 304 interfaced via a proxy interface 306 . The process of making a cell service request and the subsequent creation of a proxy agent happen within application environment 318 . Application 342 could have all the required processes to accomplish this task, but most likely there will be processes available to application 342 in application environment 318 to support agent service request 310 , and the creation of agent 308 and/or proxy agent 312 . It should be understood that, while only one cell, one service, one agent and one interface are shown by way of example, multiple cells, services, agents and interfaces might be present.
If agent service request 310 is accepted by cell 300 , agent 308 's code is moved into cell 300 and is instantiated as agent 304 therein. Then, proxy agent 312 is created within application environment 318 . Proxy agent 312 provides for controlled communication between instantiated agent 304 and application 342 . The communication is via an agent channel 316 . Agent channel 316 might use the globally unique identifiers (GUIDs) to maintain a point-to-point link.
Once the agent moves to cell 300 , cell 300 uses a reflection mechanism on instantiated service 302 to get a reference to the service interface and the methods offered by service 302 to agent 304 . Cell 300 uses the references acquired through reflection to provide proxy interface 306 to agent 304 . Agent 304 uses the published agent service description held in an agent service registry (such as agent service registry 34 shown in FIG. 1 ) to transact with what it believes is the instantiated service 302 while in actuality it interacts with cell 300 . When the agent completes its tasks, it makes a request for termination, resulting in either disposal by cell 300 or a return to a destination accessible by the application 342 that dispatched the agent. The latter is useful where the agent obtains state during execution that was not present when agent dispatcher 314 dispatched the agent to cell 300 .
FIG. 4 illustrates an example data structure representing an agent invoke service description, as might be used in the transaction that occurs in agent service request 310 .
FIG. 5 is an illustration of a system stack 500 illustrating the relationships between the various modules, including a cell 510 , an agent 512 , a service object 514 , a physical/protocol layer 516 and a system application programming interface (API) 518 . Cell 510 contains agent 512 and service object 514 and, at a lower level, includes physical and protocol modules 516 . Where all modules have access to API 518 and both agents and services are migrated to the cell from possibly untrusted sources and run within the cell, security is a key concern.
To protect the cell (and its execution hardware, data, environment, etc.), various security steps can be taken. For example, the cell might require verified digital signatures for both services and agents before allowing them to execute. If the system supports a low level API to monitor system functions, it may provide for greater control and security. Communications channels within the cell system can use a standards-based encryption mechanism, such as Secure Socket Layer (SSL), to ensure that the contents of communications remain secure.
Communication between cell systems (such as cell system 5 shown in FIG. 1 ) located on a local network can be done using both unicast (point-to-point delivery) and broadcast network packet delivery, where network packets are sent to all computing devices on a network interested in receiving the broadcast. Referring back to FIG. 1 , service finder 24 , service publishing object 32 , agent service finder 44 and the inter-cell communication channel 86 (described further below) might each use broadcasts or multicast to communicate between cell systems, while service grabber 26 , agent grabber 50 and agent service request handler 48 might use unicast packet delivery methods. The agent channel 216 shown in FIG. 2 for providing communication between instantiated agents and proxy agents might also use unicast packet delivery methods.
Where cell systems are separated by firewalls, a bridge server might be needed to handle inter-system communications. FIG. 6 shows a bridge server 602 used to connect a local network 610 A behind a firewall 613 A to a local network 610 B behind a firewall 613 B over a network such as Internet 614 . Cell 612 A and cell 612 B use bridges 618 A and 618 B, which are configured to know the network location of bridge server 602 (such as its IP address). Bridges 618 periodically check with bridge server 602 and retrieve or deliver packets between cell module sets 620 A and 620 B. Cell module sets 620 A and 620 B and their modules need not be aware that they are communicating across a firewall.
Cell System Process Flow
FIG. 7 is a flow chart illustrating a cell start up process including loading services. As shown there, a cell hosted on a computing device starts running (step 710 ) either through an automatic startup mechanism such as UNIX System V (SYSV) initialization or through various other startup processes, including being started manually. At startup, the cell might load previously active services ( 712 ). These previously active services might be loaded from a persistent store or from locations determined using a service finder, such as service finder 24 shown in FIG. 1 . Using a service finder, a cell can locate published services not already active in the cell.
If a service cannot be loaded for any reason, a log entry is made to that effect ( 714 ). If the service is loaded successfully into the cell, then the cell publishes availability of the service for use by agents ( 716 ). The cell then checks for termination requests ( 718 ), terminating if a request is made, otherwise looping back to step 712 , looking for newly published services that the cell can load.
FIG. 8 is a flow chart illustrating a process of migration and using agents. FIG. 8 comprises FIGS. 8A and 8B ; FIG. 8A shows steps of an agent requesting to be migrated to a cell and creation of a proxy agent; FIG. 8B shows steps of the agent using a service by processing tasks. Based on a defined goal or task, an application will locate a service that offers results that may satisfy the application's goal or task.
According to the steps shown in FIG. 8A , once a service has been found in a particular cell, the application makes a request to that cell to load and run an agent ( 810 ) for that application (or the agent itself when the agent is acting as the application). The cell then decides whether to load the agent ( 812 ). If the cell declines, because the cell is too busy, the cell does not trust the agent, the cell cannot support the agent's needs, or for other various reasons, the cell responds to the request with an indication of why the cell will not accept the agent ( 814 ) and the cell returns to processing and/or waiting for further service requests (loping back to step 810 ).
Once an agent is loaded and running within a cell ( 818 ), the agent can invoke service methods provided by services hosted by the cell to satisfy the agent's goal or task ( 824 ). The cell checks if the task completes successfully ( 826 ) and if not, returns status to the proxy agent ( 828 ), otherwise the cell and returns a result set to the proxy agent ( 830 ). In either case, processing continues at step 832 .
In step 832 , the cell determines whether more service tasks need to be run. If yes, the process loops back to step 824 , otherwise processing continues with step 834 , wherein return status is provided to the proxy agent. The agent will loop through all tasks that may be satisfied by the services provided within the cell. If there are no more tasks to be run, a status message is returned to the proxy agent and the agent will ether request to be moved to another cell or will shut itself down ( 836 ).
The cell will continue running until it is shut down ( 838 ).
Inter-cell Communication
Inter-cell communication object 86 (shown in FIG. 1 ) can be used to for traffic between cells and between computing devices. Cells can broker the initial loading and instantiation of services and move services to more appropriate devices or environments using object 86 to coordinate such transfers. Object 86 can also provide for encrypted communications if requested by cell 12 .
FIG. 9 illustrates an example data structure representing a cell-to-cell interprocess communication description.
Journaling
A journal-reporting system 88 (shown in FIG. 1 ) can be implemented to maintain the state of a cell, provide cell monitoring capabilities to external management processes, and facilitate roll-back if a service or agent corrupts a cell. System 88 might also support a costing/billing capability, where costs and benefits of running services and/or agents are allocated among service providers and agents. Information in a persistent storage area such as might be maintained within journal-reporting system 88 to provide service costing information as reflected in a monetary amount, possibly as reflected in computing device performance metrics. Information in the persistent storage area might also provide a reputation system wherein applications and agents can rate the level of satisfaction had using a service.
Referring to FIG. 10 , and expanding on journal-reporting system 88 , suppose an agent 952 A desires to use services 928 A, 928 B and 928 C under the control of a transaction manager 990 . Suppose further that agent 952 A also wants to access a service 914 outside of transaction control.
Before any tasks between the step denoted in 952 A as “Begin Transaction” and the step denoted “End Transaction” are run, transaction manager 990 notifies each service that will be involved in the transaction that they should prepare themselves to run under transaction control. In the case of the example shown in FIG. 10 , the tasks A, B and C of Agent A ( 952 A) require service A 928 A, service B 928 B and service C 928 C, so each service is notified by transaction manager 990 to prepares themselves for the processing that will follow up until a commit or abort notification is sent from transaction manager 990 ending the transaction. The initial preparation often entails making sure the initial state of the service is preserved, as the service may be called on to roll back to this initial state if any service involved in the transaction fails and transaction manager 990 sends an abort and rollback notification to the services involved in the transaction.
If any service 928 A, 928 B or 928 C is not able to satisfy the agent's request, then the service should update journal-reporting system 88 with information about the failure and transaction manager 990 should notify all services 928 A, 928 B and 928 C that they should roll back their processing as described above. Services that will be involved in transaction need to be designed for transaction support and able to respond appropriately to the messages sent by the transaction manager. In particular, messages might include: 1) prepare for running under transaction support, 2) abort and roll-back to initial service state, 3) commit the state at the end of the transaction.
Transactional support becomes more complicated when a service involved in a transaction is dependent on the results of another service, as a potential dead lock could occur. One solution is to run the agent task using a proxy interface (such as proxy interface 54 shown in FIG. 1 ) but not immediately return the service results to the agent. Instead, the results are cached within the proxy interface and only at the end of all transaction processing the results are returned to the agent.
Using the teachings described herein, a cell system can be used to connect up agents and services in a controlled manner, even if the entity controlling a cell system cannot fully trust the providers of agents and services. Using a cell system with services being loaded into the cell and used by agents, an application can be built. Using the cell system, not only can applications be built, but a platform such as an entire an operating system could be built. Furthermore, the platform could be distributed and the services and agents within the cells could offer discrete operations. For example, one cell could offer security on a particular physical platform while another cell may offer network storage.
As described above, a computing device instantiates a cell, then that cell loads services according to criteria and conditions under which that cell is willing to operate. The cell then advertises the services it has loaded or is willing to load. Agents find cells advertising services that the agents need and send agent load requests to those cells. The cells consider agent load requests and load approved agents. The instantiated agents in a cell interact with the instantiated services in the cell via a sell proxy interface. A journaling system can be provided for tracking, auditing and supporting transaction processing and rollbacks. Intercell system communications might also be provided.
The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those of skill in the art upon review of this disclosure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
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System and method for using cells as a type of managed container to control the operation of mobile software agents and the run-time invocation and use of services within distributed computing environments. The cell process initially starts out empty containing nether agents nor services. The cell discovers and loads published services at run-time through a look up into a distributed service registry. After loading the service, the cell then publishes availability of the service for use by agents. If an application using agents or an agent desires to make use of a service published and provided by a cell, the application or agent makes a request to the cell to fetch an agent that will invoke the service. Prior to migrating to its new cell, the agent creates a proxy agent that provides a communication channel between the agent running within the cell and the originating agent system. Service status and results are returned through the proxy channel.
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This application is a 371 of PCT/US96/14242 filed Sept. 5, 1996.
This invention concerns a method for treating and preventing inflammation or atherosclerosis in mammals by administering a compound which is an inhibitor of the enzyme 15-lipoxygenase (15-LO).
BACKGROUND OF THE INVENTION
Atherosclerosis is a multifactorial disease characterized by excessive intracellular lipid deposition in macrophages, leading to formation of foam cells. The accumulation of lipid-loaded foam cells in the subendothelial space leads to formation of fatty streaks, which are the early atherosclerotic lesions. Oxidative modification of lipids, specifically low-density lipoprotein, has been implicated as a major process in foam-cell formation.
Lipoxygenases are nonheme iron-containing enzymes that catalyze the oxygenation of certain polyunsaturated fatty acids such as lipoproteins. Several different lipoxygenase enzymes are known, each having a characteristic oxidation action. One specific lipoxygenase, namely 15-LO, has been detected in atherosclerotic lesions in mammals, specifically rabbit and man. The enzyme, in addition to its role in oxidative modification of lipoproteins, is important in the inflammatory reaction in the atherosclerotic lesion. Indeed, 15-LO has been shown to be induced in human monocytes by the cytokin IL-4, which is known to be implicated in the inflammatory process.
Another class of lipoxygenase enzymes is 5-lipoxygenase (5-LO). While this enzyme causes oxidation of unsaturated fatty acids, it primarily is responsible for inserting oxygen on position 5 of arachidonic acid. Other lipoxygenases are known; one of the most common and abundant being 12-lipoxygenase (12-LO).
We have now found that inhibitors of 15-LO are especially useful to prevent and treat inflammation and atherosclerosis. While there are several lipoxygenase enzymes, specific inhibition of 15-LO is critical in the inflammatory and atherosclerosis process. All that is required according to this invention is to administer a 15-LO inhibitor, and especially one that is a specific 15-LO inhibitor.
Several classes of organic compounds are 15-LO inhibitors.
Tetracyclic indole and benzopyranoindole compounds are potent 15-LO inhibitors. U.S. Pat. No. 3,388,133 describes benz[b]indolo[2,3-d]-thiopyrano and pyrylium salts as antibacterial and antifungal agents. U.S. Pat. No. 4,132,714 describes a process for making chromenoindoles, which are said to be useful as color-forming agents. U.S. Pat. No. 4,797,495 discloses a wide variety of benzocarbazoles which are said to be antitumor agents. Similarly, benzimidazoles are well known as antiviral agents. U.S. Pat. No. 4,293,558 describes various 1-thiazolinyl-2-aminobenzimidazoles, and U.S. Pat. No. 4,243,813 describes 1-sulfonyl-benzimidazoles. None of those compounds have been described as inhibitors of 15-LO, and none have been utilized in treating inflammation or atherosclerosis. All of these compounds are 15-LO inhibitors and can be employed in the method of this invention.
We have now discovered that compounds which are effective inhibitors of 15-LO are useful in treating and preventing inflammation and atherosclerosis.
SUMMARY OF THE INVENTION
This invention provides a method for treating and preventing inflammation or atherosclerosis in mammals comprising administering an effective amount of a 15-LO inhibitor. The invention preferably employs a specific 15-LO inhibitor. In a preferred embodiment, the 15-LO inhibitor is a benzopyranoindole or related compound as described in U.S. Pat. Nos. 3,388,133, 4,132,714, and 4,797,495, which are incorporated herein by reference. Especially preferred 15-LO inhibitors have Formula I ##STR3## wherein: R 1 is hydrogen or C 1 -C 6 alkyl;
R 2 , R 3 , R 4 , and R 5 independently are hydrogen, C 1 -C 6 alkyl, nitro, halo, CN, OR 6 , NR 6 R 7 , --CO 2 R 6 , CONR 6 R 7 , CH 2 OR 6 , or CH 2 NR 6 R 7 , and R 2 and R 3 , and R 4 and R 5 , when attached to adjacent ring atoms, can be --(CH 2 ) 3 or 4 --;
in which R 6 and R 7 independently are hydrogen, C 1 -C 6 alkyl, phenyl or benzyl, and when taken together with the nitrogen to which they are attached, R 6 and R 7 can complete a cyclic ring having from 3 to 7 carbon atoms; ##STR4## in which R 8 , R 8' , R 9 , and R 9' independently are hydrogen or C 1 -C 6 alkyl, n is 0, 1, or 2, and Z.sup.⊖ is an anion, and pharmaceutically acceptable salts thereof.
A preferred method according to this invention employs a compound of the formula ##STR5## where R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , and Z.sup.⊖ have the above defined meanings. Within this group, preferred compounds to be employed are those wherein R 1 is hydrogen, and one or two of R 2 , R 3 , R 4 , and R 5 are selected from C 1 -C 6 alkyl, halo, nitro, or OR 6 , where R 6 is preferably C 1 -C 6 alkyl.
Another preferred embodiment utilizes compounds of the formula ##STR6## where R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , and R 8' are as defined above.
Another preferred method of treatment employs a compound of the formula ##STR7## where R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , and R 9 are as defined above.
Benzimidazole 15-LO inhibitors to be employed in the method of this invention are known and readily available as described in any of the following United States patents, all of which are incorporated herein by reference: U.S. Pat. Nos. 3,853,908; 3,682,952; 3,850,954; 4,118,742; 4,196,125; 4,216,313; and 4,492,708. Additional benzimidazoles are described in the book entitled Benzimidazoles and Congeneric Tricyclic Compounds, P. N. Preston, Ed., John Wiley & Sons, also incorporated herein by reference.
In a preferred embodiment, the 15-LO inhibitor utilized is a benzimidazole having the Formula II ##STR8## where R 2 and R 3 independently are hydrogen, C 1 -C 6 alkyl, nitro, halo, CN, OR 6 , NR 6 R 7 , --CO 2 R 6 , CONR 6 R 7 , CH 2 OR 6 , or CH 2 NR 6 R 7 , and R 2 and R 3 when attached to adjacent ring atoms can be --(CH 2 ) 3 or 4--;
R 6 and R 7 are as defined above;
R 10 is SO 2 R 12 , hydrogen, C 1 -C 6 alkyl, phenyl, or phenyl substituted with 1, 2, or 3 groups selected from halo, CN, OR 6 , C 1 -C 6 alkyl, NR 6 R 7 , CO 2 R 6 , CONR 6 R 7 , CH 2 OR 6 , or CH 2 NR 6 R 7 ; and
R 11 and R 12 independently are hydrogen, halo, NR 6 R 7 , OR 6 , C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl optionally containing an O, N, or S atom, phenyl, or phenyl substituted by 1, 2, or 3 groups selected from halo, CN, OR 6 , C 1 -C 6 alkyl, NR 6 R 7 , --CO 2 R 6 , CONR 6 R 7 , CH 2 OR 6 , or CH 2 NR 6 R 7 .
Another preferred method employs a benzimidazole of the formula ##STR9## where R 13 is phenyl, 4-chlorophenyl, 4-fluorophenyl, 4-nitrophenyl, 2,5-dichlorophenyl, 2-furanyl, 2-thienyl, 3-pyridyl, or 4-pyridyl.
In another embodiment, the 15-LO inhibitor utilized is a substituted indole. Typical indoles which can be employed include the carbamates and ureas of Formula III ##STR10## wherein Y is CH 2 , S, O, or NR 7 , and R 1 , R 2 , R 3 , and R 6 are as defined above, and Ar is phenyl, Het, and phenyl or Het substituted with 1, 2, or 3 groups selected from halo, CN, OR 6 , C 1 -C 6 alkyl, NR 6 R 7 , --CO 2 R 6 , CONR 6 R 7 , CH 2 OR 6 , or CH 2 NR 6 R 7 , where Het is a heterocyclic group selected from thiophene, furan, pyrrole, isopyrrole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, oxazole, isoxazole, thiazole, isothiazole, 1,2,3-oxadiazole, thiazine, pyridine, pyrazine, piperazine, pyrrolidine, piperidine, and pyridazine, and where Het is optionally substituted with phenyl or substituted phenyl, furanyl, thienyl, or pyridyl, and where R 6 and R 7 are as defined above. A particularly preferred group of compounds to be employed in the method have the formula ##STR11## where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and Y are as defined above. Such compounds are described in EP 0150505, which is incorporated herein by reference.
Another class of 15-LO inhibitors which can be utilized in the invention are styrenes having the Formula IV ##STR12## wherein Ar and Ar' independently are phenyl, Het, and phenyl or Het substituted with 1, 2, or 3 groups selected from halo, OR 6 , C 1 -C 6 alkyl, NR 6 R 7 , --CO 2 R 6 1 , CONR 6 R 7 , CH 2 OR 6 , and CH 2 NR 6 R 7 , where R 6 and R 7 are as defined above.
A preferred method employs styrene 15-LO inhibitors of the formula ##STR13## where R 2 , R 3 , and Het are as defined above.
Another group of 15-LO inhibitors are catacholes, compounds of the Formula V ##STR14## wherein R 2 , R 3 , and R 6 are as defined above.
Still other 15-LO inhibitors that can be utilized are naphthalenes, especially those of Formula VI ##STR15## wherein R 1 , R 2 , R 3 , and R 6 are as defined above, and M is hydrogen or a cation such as sodium, potassium, or calcium. Such compounds are described in U.S. Pat. No. 4,608,390, incorporated herein by reference.
Another class of 15-LO inhibitors are benzoxadiazines of the general Formula VII ##STR16## where R 1 , R 2 , R 3 , and Ar are as defined above. Such compounds are described in EP 0410834.
A preferred embodiment utilizes a benzo[a]phenothiazine which is described in U.S. Pat. No. 4,876,246, incorporated herein by reference. Related 15-LO inhibitors that can be employed are phenothiazone derivatives described in U.S. Pat. No. 4,939,145, incorporated herein by reference.
Especially preferred from such classes are compounds having the formulas ##STR17## where R 1 , R 2 , R 3 , R 4 , R 5 , and Y are as defined above. Such compounds are specifically described in U.S. Pat. Nos. 4,876,246 and 4,939,145.
All that is required to practice the method of this invention is to administer to a mammal a 15-LO inhibiting amount of a 15-LO inhibitor, preferably a specific 15-LO inhibitor.
DETAILED DESCRIPTION OF THE INVENTION
The term "C 1 -C 6 alkyl" means a straight or branched carbon chain such as methyl, ethyl, isopropyl, n-butyl, tert-butyl, sec.-pentyl, 3-methylpentyl, and the like. "Halo" means fluoro, chloro, bromo, and iodo. Ring substituents R 2 , R 3 , R 4 , and R 5 can be OR 6 , where R 6 can be hydrogen or C 1 -C 6 alkyl. Typical groups defined by OR 6 include hydroxy, methoxy, isopropoxy, tert-butoxy, n-hexyloxy, and the like. Ring substituents also are defined by NR 6 R 7 , which groups include amino, methylamino, diethylamino, N-methyl-N-isohexylamino, and the like. The ring substituents R 2 , R 3 , R 4 , and R 5 can also be a carboxylic acid, ester, carboxamide, and methylamino group. Typical esters include methoxycarbonyl and ethoxycarbonyl. Typical carboxamide groups include aminocarbonyl, methylamino-carbonyl and N,N-diethylaminocarbonyl. Typical methylamino groups include methylaminomethyl, ethylaminomethyl, and the like.
The term "Z.sup.⊖ " in the above formula is an anion such as perchlorate or halide, for instance chloride, bromide, or the like.
The compounds to be employed in the method of this invention are known. They can be prepared by processes described in the art. For example, U.S. Pat. No. 3,388,133, which is incorporated herein by reference, describes reaction of a phenylhydrazine with a thiochroman-4-one to give compounds of Formula I wherein X is ##STR18## This reaction scheme is applicable to other compounds, for example according to the following scheme ##STR19##
The 15-LO inhibitors are effective for treating inflammation and atherosclerosis. A characteristic feature of atherosclerosis is the accumulation of cholesterol ester engorged from foam cells. Foam cells are derived from circulating monocytes which invade artery walls in response to hypercholesterolemia, and mature into tissue macrophages. The enzyme 15-LO has been implicated in inflammatory disorders and in the origin and recruitment of foam cells (see Harats, et al., Trends Cardioivasc. Med., 1995;5(1):29-36). This enzyme is capable of oxidizing esterified polyenoic fatty acids, such as those found in phospholipids. Treatment of experimental animals with antioxidants which reduce hydroperoxides produced by 15-LO has been shown to retard the progression of atherosclerotic lesions. Accordingly, administering compounds which inhibit 15-LO is an effective way to treat and prevent atherosclerosis.
The compounds described above are effective inhibitors of 15-LO when evaluated in standard assays routinely utilized to measure 15-LO activity. Specifically, representative compounds were evaluated by the methods described by Auerbach, et al., Analytical Biochemistry, 1992;201:375-380. Two in vitro assays were utilized, both utilizing rabbit reticulocyte 15-LO, and linoleic acid as substrate, to enzymatically produce a peroxide oxidation product known as 13(S)-HPODE. N-Benzoyl leucomethylene blue was utilized as a calorimetric reagent for detection and quantification of the peroxide formation. Also, HPLC was utilized to quantify the oxidation following incubation at 4° C. for 10 minutes.
The 15-LO inhibitory activity of representative compounds is presented in Table 1. Data Column 1 gives the concentration of compound required to inhibit 50% of the activity of 15-LO (IC 50 ) when measured by the HPLC method of Auerbach, et al. Data Column 2 gives the concentration of selected compounds to inhibit 50% of the activity of the 5-LO enzyme.
TABLE 1______________________________________Compounds of the Formula #STR20## - 15-LO R.sup.2 R.sup.3 R.sup.4 R.sup.5 R.sup.8 IC.sub.50 μM 5-LO______________________________________ H H H H H 1.0-4.0 H H NO.sub.2 H H 0.48 >10 H H Cl H H 12.0 H H CH.sub.3 H H 1.9 H H H CH.sub.3 H 1.0-4.0H H --(CH.sub.2).sub.4 -- H 0.5-2.0 >32H CH.sub.3 O-- H H H 0.70 >9.6 CH.sub.3 O H H H H 26.0 H H H H CH.sub.3 >25 #STR21## H H H H H 3.8 22 #STR22## H H H H H 1.3 >100 H CH.sub.3 O-- H H H 0.6 >10 CH.sub.3 O-- H H H H 4.5 >50 #STR23## H CH.sub.3 O-- H H H 4.0 >50 #STR24## H CH.sub.3 O-- H H H >25 μm #STR25## H CH.sub.3 O-- H H H >25 μM #STR26## H H H H H 1.5 >10______________________________________
As noted above, benzimidazoles are especially preferred 15-LO inhibitors to be employed in the claimed method. The 15-LO inhibitory activity of typical benzimidazoles are given in Table 2.
TABLE 2______________________________________Compounds of the Formula #STR27## - 15-LO 5-LO R.sup.2 R.sup.3 R.sup.10 R.sup.11 IC.sub.50 μM IC.sub.50 μM______________________________________ H H H 1.50 8## >10 - H 5-Cl H 0.65 >10 - H 5-Cl H 0.7 >10 - H 5-Cl H 0.24 >10______________________________________
Styrenes are potent 15-LO inhibitors which can be employed in the present method. Table 3 gives the 15-LO inhibitor of typical styrenes.
TABLE 3______________________________________ #STR32## - 15-LO 5-LO R.sup.2 R.sup.3 Het IC.sub.50 μM IC.sub.50 μM______________________________________ H 4-OCH.sub.3 1.6 >10#______________________________________
Typical indole 15-LO inhibitors which can be utilized have the activities shown in Table 4.
TABLE 4______________________________________ #STR34## - 15-LO 5-LO R.sup.1 R.sup.2 R.sup.3 R.sup.4 R.sup.5 R.sup.6 Y IC.sub.50 μM IC.sub.50 μM______________________________________H H H H 3-Cl H S 4 >10 H H H H H H CH.sub.2 1.5 >10______________________________________
Table 5 gives additional selectivity data for typical 15-LO inhibitors which can be utilized in the method of this invention.
TABLE 5______________________________________ 15-LO 5-LO IC.sub.50 μM IC.sub.50 μM______________________________________ 2.0 35## >30 - 1.5 >10 - CH.sub.3 (CH.sub.2).sub.3 (CH.sub.2 --C.tbd.C--).sub.4 (CH.sub.2).sub .3 --COOH 0.75 >10______________________________________
As further evidence of 15-LO inhibitors being effective to prevent and treat inflammation and atherosclerosis in animals, one representative compound has been extensively evaluated in cholesterol-fed rabbits over a 12-week period. The compound evaluated "Compound A" was 6,11-dihydro[1]benzothiopyran[4,3-6]-indole, the compound of Formula I where R 1 , R 2 , R 3 , R 4 , and R 5 each are hydrogen, and X is --CH 2 --S--, i.e., ##STR37##
Specific pathogen-free New Zealand White rabbits (≈2.5 kg) were obtained from Myrtle's Rabbitry (Thompson Station, Tenn.). The animals were fed a standard laboratory diet (Ralston Purina, St. Louis, Mo.) and were allowed to become acclimatized for 7 days before initiation of the study, at which time two groups of rabbits (n=10 each) were begun on a diet enriched with cholesterol (0.25% wt/wt), peanut oil (3% wt/wt), and coconut oil (3% wt/wt), with a small amount of applesauce mixed into the food to enhance palatability. This diet was designed to produce a modest hypercholesterolemic response. The control group received no additional treatment. The drug-treated group received 350 mg of Compound A per kilogram body weight per day in their food. Rabbits were permitted access to 40 g of food at ≈12 hour intervals via automated feeders, and diet intake was monitored every day such that the animals received 175 mg/kg/bid. Water was available ad libitum. Body weights were measured at regular intervals throughout the 12-week study. Blood samples were obtained at the indicated intervals for determination of hematocrit and plasma lipid concentrations.
Characterization of Atherosclerotic Lesions
Rabbits were euthanized by an overdose of sodium pentobarbital (150 mg/kg -1 ) and exsanguinated via the abdominal aorta. Aortas were removed from the valve to the ileal bifurcation, opened to expose the intima, and photographed with a Polaroid camera. By use of these photographs, the areas of grossly discernible atherosclerosis were manually integrated on a digitizing pad and calculated with SigmaScan (Jandel Scientific). Aortas were visually subdivided into three areas: arch (aortic valve to first intercostal), thoracic aorta (first intercostal to diaphragm area), and abdominal aorta (diaphragm to ileal bifurcation). In addition to extracting aortas, body tissues were surveyed for indications of adverse reactions.
Determination of Cholesterol Esters and Unesterified Cholesterol Content
Weighed segments of each aortic region (arch, thoracic, and abdominal) were extracted. Esterified and unesterified cholesterol content of aortic tissue were determined by gas chromatography using 5-α-cholestane as an internal standard.
In the control group, the arch area of aortic sections demonstrated about 15% lesion coverage of intima, whereas those animals receiving Compound A showed no lesion coverage. No detectable lesions were seen in either group in the thoracic region. In the abdominal region, the control group exhibited 5% lesion coverage, whereas the treated group exhibited about 1%. The treated group had no detectable cholesterol esters present in the arch, thoracic, or abdominal regions, whereas the control group had about 2 mg/g tissue wet weight of cholesterol esters in the arch region, none in the thoracic region, and about 0.6 mg/g in the abdominal region. Test animals and the control group had about the same amount of unesterified cholesterol in the thoracic and abdominal regions (0.7-0.8 mg/g tissue wet weight), while in the arch region, the control group had about 1.4 mg/g while the treated group had about 0.8 mg/g.
These data establish that administration of a 15-LO inhibitor effectively protects against the development of atherosclerosis in animals.
In an especially preferred embodiment of this invention, the 15-LO inhibitor utilized is a specific inhibitor of 15-LO. The term "specific" as used herein means that a compound inhibits 15-LO at least about ten-fold (10×) more effectively than it inhibits 5-LO. For example, a preferred group of compounds to be employed in the present method are defined by Formula I. A typical compound from within that group is 6,11-dihydro[1]benzothiopyrano[4,3-b]-indole (Compound A). Its 15-LO inhibitory activity is an IC 50 of 1.3 μM, and its 5-LO inhibitory activity is >100 μM. The compound thus inhibits 15-LO at least about 100 times more potently than it inhibits 5-LO. The compound is therefore a "specific" 15-LO inhibitor for purposes of this invention.
Similarly, a preferred benzimidazole to be employed in the invention is 2-(4-chlorophenyl)-5-chlorobenzimidazole. It has a 15-LO IC 50 of 0.65 μM, and a 5-LO IC 50 of greater than 10 μM. Accordingly, its 15-LO to 5-LO ratio of activities is greater than 10, thus making the compound a specific 15-LO inhibitor according to this invention.
All that is required to practice this invention is to administer to a mammal an effective amount of any compound that is a 15-LO inhibitor. For example, the compounds of Formula I are useful for treating atherosclerosis and inflammation by virtue of their ability to inhibit 15-LO as established by the data in Table 1. Accordingly, any compound that is determined to inhibit 15-LO in a test system, such as described above, can be employed in this invention.
For use according to this invention, the compounds can be formulated into compositions suitable for administering to animals, including humans, for treating and preventing inflammation and atherosclerosis. The compounds can be formulated for administration by any route, for instance orally, parenterally, topically, and rectally. For oral administration, for example, a 15-LO inhibitor can be mixed with an inert diluent or with an assimilable edible carrier, or it may be enclosed in a hard or soft shell gelatin capsule, or it may be compressed into tablets, or it may be incorporated directly with the food of the diet. For oral therapeutic administration, the active compound may be incorporated with excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contain at least 1% by weight of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 5% to about 80% of the weight of the unit. The amount of active compound in such therapeutically useful compositions is such that a therapeutically effective dosage will be obtained. Preferred compositions or preparations according to the present invention are prepared so that an oral dosage unit form contains between about 5 and 1000 mg of active compound, and ideally about 25 to about 750 mg.
The tablets, troches, pills, capsules, and the like may also contain common pharmaceutical excipients such as binders, sweeteners, and the like. Typical binders include gum tragacanth, acacia, corn starch, and gelatin, as well as excipients such as dicalcium phosphate. Typical disintegrating agents include corn starch, potato starch, alginic acid, and the like. A commonly used lubricant is magnesium stearate. Typical sweetening agents are sucrose, lactose, or saccharin, and flavoring agents such as peppermint, oil of wintergreen, or cherry flavoring can be utilized. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. For instance, tablets, pills, or capsules may be coated with shellac, sugar, or both. A syrup or elixir may contain the active compound, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye, and flavoring such as cherry or orange flavor. Of course, any material used in preparing any dosage unit form should be pharmaceutically pure and substantially nontoxic in the amounts employed.
The 15-LO inhibitors can also be formulated for topical administration, for instance as patches, salves, creams, ointments, and the like. Agents commonly utilized to enhance transdermal passage can also be employed. The compounds can also be formulated with waxes and the like for convenient rectal administration.
The active 15-LO inhibitor may also be administered parenterally or intraperitoneally. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations may contain a preservative to prevent the growth of microorganisms.
The pharmaceutical forms suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin; by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.
Sterile injectable solutions are prepared by incorporating the active compound in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredient into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze-drying technique which yield a powder of the active ingredient plus any additional desired ingredient from previously sterile-filtered solution thereof.
As used herein, "pharmaceutically acceptable carrier" includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like. The use of such media and agents for pharmaceutical active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in the therapeutic compositions is contemplated. Supplementary active ingredients can also be incorporated into the compositions.
It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the mammalian subjects to be treated; each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms are dictated by and directly dependent on (a) the unique characteristics of the active material and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active material for the treatment of disease in living subjects having a diseased condition in which bodily health is impaired as herein disclosed in detail.
The principal active ingredient is compounded for convenient and effective administration in effective amounts with a suitable pharmaceutically acceptable carrier in dosage unit form as hereinbefore disclosed. The term "effective amount" means that quantity of a 15-LO inhibitor which has a positive therapeutic effect for treating or preventing the inflammation or the atherosclerosis which affects the mammal. Such amount is that which inhibits the 15-LO enzyme; in other words, a 15-LO inhibiting amount. A unit dosage form can, for example, contain the principal active compound in amounts ranging from about 5 to about 1000 mg, with from about 25 to about 750 mg being preferred. A typical dose will be about 50 to about 500 mg. In the case of compositions containing supplementary active ingredients, the dosages are determined by reference to the usual dose and manner of administration of the said ingredients. The unit dosages typically will be administered from one to four times per day, or as otherwise needed to effect treatment of the disease state.
The invention therefore is a method for treating and preventing inflammation and atherosclerosis in mammals. The compounds are effective in inhibiting the activity of 15-LO, and as such can be administered to a mammal, including a human, to effectively diminish and treat atherosclerosis and inflammation. The compounds will be administered at a dose which is effective to treat atherosclerosis, typically from about 1.0 to about 100 mg/kg of body weight of the subject being treated.
The compounds also are useful for treating and preventing inflammation, for example, swelling due to injuries, swelling around bones and joints, and the like. The compounds will be administered to an animal suffering from inflammation in an anti-inflammatory effective amount that is effective to treat the inflammation. Typical doses will be from about 1.0 to about 100 mg/kg of body weight.
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This invention provides a method for treating or preventing inflammation or atherosclerosis in mammals comprising administering an effective amount of a 15-LO inhibitor of Formula I: ##STR1## wherein: R 1 is hydrogen or C 1 -C 6 alkyl;
R 2 , R 3 , R 4 , and R 5 independently are hydrogen, C 1 -C 6 alkyl, nitro, halo, CN, OR 6 , NR 6 R 7 , --CO 2 R 6 , CONR 6 R 7 , CH 2 OR 6 , or CH 2 NR 6 R 7 , and R 2 and R 3 , and R 4 and R 5 , when attached to adjacent ring atoms, can be --(CH 2 ) 3 or 4 --;
in which R 6 and R 7 independently are hydrogen, C 1 -C 6 alkyl, phenyl or benzyl, and when taken together with the nitrogen to which they are attached, R 6 and R 7 can complete a cyclic ring having from 3 to 7 carbon atoms; ##STR2## in which R 8 , R 8' , R 9 , and R 9' independently are hydrogen or C 1 -C 6 alkyl, n is 0, 1, or 2, and Z.sup.⊖ is an anion, and pharmaceutically acceptable salts thereof.
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BACKGROUND OF THE INVENTION
The invention relates to a syringe useful for both injection and aspiration.
Various syringe types are available in which the changes in resistance during movement of the plunger (so-called loss of resistance syringe) is used during localization of the epidural area. Suitable syringes comprising a plastic barrel and plunger have in common that little resistance is off, red to the advance movement of the syringe plunger, so that any change in pressure is directly transmitted and can hence be detected.
In addition, the syringe should have the property that during movement of the plunger the friction between the latter and the inner wall of the barrel is constant over the entire plunger stroke, so that an even plunger movement can be achieved by slight pressure on the plunger itself.
A syringe consisting of plastic and having these properties, intended for once-only use, was developed by Portex. This is a three-part syringe, the main advantage of which lies in the high dimensional accuracy of plunger and barrel, thereby permitting a good pressure transmission with low friction. As a result of the plunger form, however, this syringe could only operate effectively during injection, since during sucking the gasket between the plunger and the inner wall of the barrel only had an inadequate effect, such that when the plunger was retracted the vacuum built up was insufficient to suck in fluid.
A further syringe having the properties as described at the outset has been developed by Braun. However, this syringe revealed the same drawbacks during sucking as the Portex syringe, i.e. use in sucking applications was not generally possible.
A further syringe is described in FR 1,048,267. The gasket shown in FIG. 8 comprises three sections, an innermost of which has a rectangular geometry and extends over the full width of a syringe plunger groove holding the gasket. According to FIG. 7, the gasket can comprise a large outer section of rectangular cross-section pressing against the barrel inner wall of the syringe and a small web-like inner section. The gasket here is fairly rigid and does not provide an adequate sealing effect during injection or sucking.
CH 286 277 describes an injection syringe composed of an outer salient section in a wide-area contact with the inner wall of the barrel of the syringe and of an inner membrane-like section surrounding the syringe plunger.
A gasket for an injection syringe in accordance with FR 1,108,413 comprises an outer section of droplet shape that merges into an inner salient section via a web. Both the outer and the inner sections are in wide-area contact with the barrel inner wall or the plunger of the syringe.
A syringe having an O-ring disposed in an all-round groove of the syringe barrel is known from U.S. Pat. No. 4,632,672.
DE 1,566,602 describes an injection syringe consisting of plastic and having the drawbacks described at the outset.
A flat gasket is used in accordance with DE 2,024,117 for sealing a plunger in relation to a barrel of an injection syringe consisting of plastic.
Further syringes are described in U.S. Pat. No. 1,154,677, U.S. Pat. No. 2,578,814, EP 0,102,070 A2, FR 4 06,988, GB 1,179,487 and DE 2,451,398 A1.
The problem underlying the present invention is to develop a syringe of the type stated at the outset such that it can be used for both injection and sucking, with low friction losses occurring at the same time while the plunger is being moved.
SUMMARY OF THE INVENTION
In order to solve this problem the gasket is composed of an annular outer section creating a sealing effect during injection or sucking and equivalent to a half-O-ring gasket, and of a central flexible skin-like or membrane-like section that is stabilized by the section that is also equivalent to a half-O-ring and that tightly encloses the plunger has the advantage that in the rest position of the plunger a possible rearward movement of the gasket does not take place. The inner section of the gasket is here designed such that resetting forces do not substantially occur, that would otherwise affect the friction forces during movement of the plunger.
The radial extent of the outer section is preferably equal to or greater than that of the inner section, i.e. of the membrane-like section by itself or together with its reinforcement. In a correspondingly preferred form of the gasket, the skin-like or membrane-like sections extending between the salient sections that are in sealing contact with the barrel inner wall or with the plunger should have a radial extent approximately that of the outer section, but at least twice as large as that of the inner section.
The gasket itself or those sections of it interacting with the plunger sections or barrel inner wall are disposed with play between the sections of the plunger when the syringe is not in use, whereas a sealing effect between the barrel inner wall and one of the sections is obtained during injection or sucking.
With the syringe in accordance with the invention, only low friction losses occur between plunger and barrel inner wall, since the plunger is only in minimal contact with the inner wall on account of the gasket. The plunger is always enclosed in substantially straight-line form both when the skin-like or membrane-like section is internal and when this section is limited by the reinforcement designed as a semicylindrical ring. A corresponding and substantially linear sealing effect is also obtained between the barrel inner wall and the outer section of the gasket. Accordingly, the force to be exerted to move the plunger is lower than in known syringes, since in the latter a heavier pressure has to be exerted on the side walls to avoid pressure losses.
The fact that the gasket automatically presses against one of the sections, i.e. during injection against the section facing away from the plunger end face and against the plunger inner wall, resulting in an automatic increase in the sealing effect as the pressure increases, ensures high dependability when the syringe is used.
The same considerations apply for sucking, as the increasing vacuum causes an increased sealing effect between the section close to the end face and the barrel inner wall.
A material should be used in the gasket having a density between 2 and 75 Shore, preferably between 30 and 50. This ensures a deformation of the gasket during injection or sucking that causes a greater sealing effect as the pressure effect increases.
The syringe in accordance with the invention is accordingly equally usable for both injection and sucking, with low friction losses thanks to the freely movable arrangement of the gasket with play between the plunger sections or the limits of the receptacle, thereby providing the possibility that the gasket is in sealing contact between one of the plunger sections and the barrel wall depending on whether the syringe is used for injection or for sucking.
Further details, advantages and features of the invention are clear from the following description of an embodiment shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a section through a first embodiment of a syringe during sucking,
FIG. 2 shows a section through the syringe according to FIG. 1 during injection,
FIG. 3 shows a gasket used in accordance with the invention in a syringe in the rest position,
FIG. 4 shows the gasket used in accordance with the invention when the syringe is in use,
FIG. 5 shows a second embodiment of a syringe,
FIG. 6 shows a plan view onto a gasket,
FIG. 7 shows a section through the gasket according to FIG. 6, and
FIG. 8 shows a section of a syringe plunger with double-dumbell-shaped gasket.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a section through a disposable syringe preferably made of plastic, using which both injection and sucking is possible. The syringe comprises a hollow barrel (10) with plunger (12) movably disposed therein. The plunger (12) has a cylindrical basic element (14) of which the outer diameter is smaller than the inner diameter of the barrel (10). On the needle side, the plunger (12) has an end section (16) that is curved on the outside and preferably follows the geometry of a spherical section. The end section (16) extends radially beyond the basic element (14) of the plunger (12), however with the maximum outer diameter being smaller than the inner diameter of the barrel (10).
The inner face (18) of the end section (16) extending from the basic element (14) is flat, as indicated in FIGS. 1 and 2.
At a distance from the face (18) is a section (20) of disk shape also extending radially beyond the basic element (14) of the plunger (12), the outer diameter of said section (20) also being less than the inner diameter of the barrel (10). The clear distance between the facing and parallel surfaces (18) and (22) of the end section (16) and of the section (20) respectively is indicated in FIG. 1 with A.
The plunger (12) and the sections (16) and (20) extending therefrom have a diameter that is slightly lower than the inner diameter of the barrel (10), so that direct contact is ruled out.
Disposed between the end section (16) and the section (20), i.e. between the surfaces (18) and (22) is a gasket (24) of which the extent in the axial direction of the plunger (12) is less than the clear distance A. The outer diameter of the gasket (24) is at least equal to the inner diameter of the barrel (10).
The gasket (24) comprises here an outer section (25) of radial extent W equivalent to an O-ring and an inner skin-like of membrane-like section (27) of radial extent M that tightly encloses the plunger section (29) of radius K.
When a syringe is not in use, the gasket (24) is disposed freely movable with the lowest possible play between the sections (16) and (20). This does not automatically result in sealing between the gasket (24) and one of the sections (16) or (20) and the barrel inner wall (26). This is made clear in FIG. 3.
If the syringe is used for sucking (FIG. 1), the plunger (12) is drawn back from the syringe needle, i.e. in the direction of the arrow (28). This movement compels the gasket (24) to make contact between the surface (18) of the end section (16) and the inner wall (26) of the barrel (10). This results in a sealing effect that increases as the plunger movement intensifies. In the same way, a pressure (indicated by the arrows 30) acts on the gasket (24), thereby increasing the sealing effect.
Consequently, problem-free sucking of fluids is possible. At the same time, however, only low friction resistances have to be overcome, since the toric gasket (24) requires only a small contact area (linear contact) with the barrel wall (26) to become effective. This does not however preclude guide projections extending from the basic element (14) and contacting the inner wall (26).
There is in the same way a linear toric seal between the inner section (27) and the plunger section (29). If necessary, that end of the gasket section (27) pressing against the plunger section can be tapered or chamfered.
However, reliable sealing is obtained with the gasket (24) not only during sucking but also during injection, more precisely between the inner wall (26) and the section (20), as made clear in FIG. 2. Because of the internal pressure buildup in the syringe, there is at the same time a pressure working on the gasket (24) (arrows 32) that ensures an increased sealing effect. This is also made clear by FIG. 4.
During injection, the plunger (12) is moved in the direction of the syringe needle, i.e. in the directions of the arrow (34).
During injection too, only a slight friction resistance occurs, since in general the gasket (24) slides along the inner wall (26), so that friction resistances between the plunger (12) and the barrel (10) in the actual sense do not have to be overcome.
FIGS. 5 to 7 show a further noteworthy embodiment that is inventive per se.
As in the embodiments according to FIGS. 1 to 4, a plunger (38) is movably disposed inside a barrel (36). The barrel is shown in section from the side, in the area of its end (42) facing the syringe head (40).
The diameter of the plunger (38) is noticeably smaller than the inner diameter of the barrel (36), so that a direct contact is ruled out. Nevertheless, a secure sealing effect is achieved between the plunger (38) and the barrel (36) during both injection and sucking thanks to the teachings in accordance with the invention.
To that end, a gasket (44) is provided in the area of the front end (42) of the plunger (38) that in the actual sense comprises an O-ring (46) as the outer all-round bead and an inner section (48) having a central hole (50). The section (48) can be of membrane-like design, and can also be designed as an all-round lip extending from the outer section (46).
The correspondingly designed gasket (44), which in section has a dumbbell-like geometry with central hole, is fixed in the area (42) of the plunger (38) in a receptacle (52) formed by an all-round depression of V-shaped section.
The radially extending limits to this depression, i.e. the outer edges (54) and (56) of the receptacle (52), end at a distance from the inner wall (58) of the barrel (36).
To obtain a sealing effect, the gasket (44) has a maximum diameter equal to or greater than the inner diameter of the inner wall (58).
In the area of the salient extension (48), the limiting walls (60) and (62) of the receptacle (52) are at a distance from one another that is greater than the diameter of the section (46) of the gasket (44). Accordingly, the gasket (44) is disposed freely movable inside the receptacle (52). This freedom of movement is not in principle restricted by the membrane-like or skin-like section (48) of the gasket (44) that is in tight all-round contact with the bottom (64) of the receptacle (52) to rule out any rearward movement of the gasket (44) when the plunger (38) is at rest. The section (48) is here designed with an inherent stiffness such that resetting forces do not occur or if so only to a negligible extent, so that consequently no increased friction forces can be caused by the section (48) either.
The radial extent W of the outer section (46) of the gasket (44) is approximately double the size of the radial extent M of the inner membrane-like section (48) that tightly encloses the bottom (64) of the receptacle (52) of V-shaped section. In addition, the diameter K in the area of the bottom (64) of the plunger (38) is equal to the entire radial extent of the outer section (46) of the gasket (44), i.e. 2 W≈K.
By the design and arrangement in accordance with the invention of the gasket (44) in the embodiment shown in FIGS. 5 to 7, the same effects are obtained as in the syringe according to FIGS. 1 to 4. This means that the all-round bead (46) is in sealing contact between the limiting wall (62) and the barrel inner wall (58) during injection, and between the limiting wall (60) and the barrel inner wall (58) during sucking.
FIG. 8 shows a particularly noteworthy embodiment of the invention. A gasket (66) is provided that comprises an outer semicylindrical ring (68), a web-like and annular central section (70), and an inner section (72) in the form of a semicylindrical ring. The gasket (66) tightly encloses a plunger (74) in a receptacle (76) and is at the same time in sealing contact with the inner wall of a barrel (not shown) of a syringe.
The receptacle or groove (76) has a flat bottom (78) running in the longitudinal direction of the plunger (74) and limited by walls (84) and (86) extending radially and vertically to the longitudinal axis of the plunger (74). This section of rectangular or square section adjoins an outward-tapering section that is limited by side walls (80) and (82). The opening angle between the side walls (80) and (82) should be between 30° and 50°, preferably about 40°.
In other words, the receptacle (76) is composed--when seen in section--of outer trapezoidal sections and inner square or rectangular sections.
The axial extent of the inner section of the receptacle (76) limiting it from the side walls (84) and (86) is greater than that of the inner section (72) of the gasket (66). In the radial extent too, the inner section of the receptacle (76) is greater. This means that the inner section (72) of the gasket (66) pressing against the bottom (78) with its convex side is completely inside the sectionally rectangular or square section of the receptacle (76).
The outer section (68), also equivalent to a half O-ring, and having a greater extent than the inner section (72) in both the axial and radial directions, is enclosed in some areas by the trapezoidal outer section of the receptacle (76), however with an axial extent that ensures that the section (68) of the gasket (66) is at a distance from the walls (80) and (82) when the syringe is at rest.
The gasket (66) of course protrudes with its outer section (68) radially beyond the plunger (74) in order to ensure a sealing contact with the barrel inner wall--not shown--of the syringe.
The inner section (72) has the effect of reinforcing the membrane-like or skin-like central section (70) without this causing resetting forces that hamper injection or sucking.
As a result of the fact that the inner section (72) presses against the bottom (78) of the receptacle (76) with its round outer face, a linear sealing action in relation to the bottom (78) is obtained on the one hand and a rolling motion during sucking or injection on the other hand, which does not build up a noticeable friction resistance.
The same applies in relation to the outer section (68), which also presses in approximately linear form against the barrel inner wall and performs a rolling movement along the inner face for sealing, in order to be in sealing contact with the wall (80) (injection) or the wall (82) (sucking).
Concerning the dimensions, it must be noted that the radial extent R 1 of the outer section (68) is approximately equal to the radial extent R 2 of the central section (70). To that end, the radial extent R 3 of the inner section (84) should be approximately half that of the central section (70) or of the outer section (68). The radius R K of the plunger in the bottom area of the receptacle (76) should by contrast be equal to or greater than the sum of the radial extents of the inner section (72) and of the central section (70).
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A syringe which is suitable for both injection and aspiration includes a plunger movable within a barrel and a gasket disposed at the distal end of the plunger at a narrowed portion of the plunger between two plunger portions of greater diameter. When the plunger is moved, the gasket forms a seal between the inner wall of the barrel and one of the portions of the plunger of greater diameter.
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BACKGROUND OF THE INVENTION
Tube forming machines generally require that segments of the tube be cutoff in a tube cutting machine, such as that described in my prior U. S. Pat. No. 4,111,346, after which the tube ends are suitably formed to provide a number of desired tube end configurations in further steps in the overall process of fabricating tube segments generally. Tube double end forming now requires that these severed segments be conveyed to a station where both ends are formed by independently operable forming devices.
The system to be described avoids the necessity for precisely positioning each tube segment at such a station in a two station process that involves a lack of control over the tube segment due to the requirement for conveying the tube segment from the cut off station to the tube end forming station.
SUMMARY OF THE INVENTION
The general object of the present invention is to provide a method and apparatus for simultaneous forming the end of a severed tube segment and the adjacent end of the tubing from which it has been severed in a single step process. A double tube end forming means is provided on a cross slide and cooperates with means for moving the severed tube segment away from the tubing end so that the double tube end forming means can be so operated. In accordance with the method of the present invention the tubing is moved intermittently through a cutoff machine of the above mentioned type by means of a feed clamp assembly operable in timed relationship therewith. The tubing is successively gripped and released and advanced in the downstream or axial direction into a work station. The cutoff head provides partial cuts at predetermined points along the tubing, and this is done in cooperation with a clamping assembly to provide partial cuts that re spaced a predetermined distance apart along the tubing. Each tube segment is gripped and pulled away so as to separate each segment in turn at the partial cut points. This is accomplished by moving the tube gripping device to a position precisely spaced downstream of its initial position and in precise alignment with the tube end that it was separated from. The tube ends are then formed by a tube end forming device that moves in between the tube ends that have just been severed. Both tube ends are formed simultaneously into any desired configuration depending upon the particular requirements of the job.
The apparatus for carrying out the above described method includes means for intermittently moving a supply of tubing in a downstream direction so that a portion projects into the work station with means being provided for partially cutting the tubing at predetermined points between the successive tubing movement. Conventional clamping means is provided in association with the cutting means for this purpose. The means for gripping the tube segment downstream of one such partial cutting point is used to move the tube segment away from the clamping means to separate the tube segment at the predetermined point and to provide the requisite spacing and alignment between the downstream end of the tubing and the upstream end of the separated tube segment for receiving a double end tube forming device that moves into the work station on a cross slide. This device simultaneously forms the adjacent ends of the tubing and tube segment and the process can be repeated continuously to produce tube segments of any desired end configuration and incidentally of any desired length.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat schematic elevational view of a machine adapted to carry out the method of the present invention, movement of the various components being illustrated by double ended arrows, and portions of the machine being broken away or shown in broken lines to better illustrate the interaction of these components.
FIG. 2 is an enlarged view of one tube segment after it has been separated from the supply of the tubing and after the ends have been formed in the apparatus of FIG. 1 and in accordance with the method of the present invention.
FIG. 3 is a plan view of the apparatus illustrated in FIG. 1, but with the tube gripping means provided in a different position, and with the double ended tube forming device provided in its inactive position.
FIG. 4 is a view similar to FIG. 3 but illustrating the tube end forming means in its active position and with the tube gripping means provided in the position shown in FIG. 1.
FIG. 5 is a view similar to FIGS. 2, 3 and 4 but with the double tube end forming means provided in its inactive position and with the gripping means having discharged a formed tube segment for transfer downstream on a take away conveyor provided for this purpose in the machine.
FIG. 6 is a view similar to FIG. 5 but with portions broken away to reveal the internal structure of the means for moving the tube segment gripping device and for adjusting its second position.
FIG. 7 is a top plan view of the double ended tube forming device and tube clamping and gripping means, in the same general positions as depicted in FIG. 4, but with portions broken away.
FIG 8 is a top plan view of the apparatus illustrated in FIG. 7 after the tube ends have been formed.
DETAILED DESCRIPTION
Turning now to the drawings in greater detail, FIG. 1 illustrates generally at 10 a typical tube cutting machine of the type described in detail in my prior U.S. Pat. No. 4,111,346. Such a machine includes means for accommodating a supply of tubing T in continuous form (such as a roll not shown) and for clamping the tubing at a predetermined point by fluid operated clamping assembly means 12 so as to permit operation of a tube cutting head 14 as illustrated in FIGS. 1, 2 and 3 of said prior U.S Pat. No. 4,111,346. Such a cutting head 14 comprises a rotary cutting head portion 14a through which the tubing passes, and in which head are provided rollers and cutting means to achieve at least a partial cut through the tubing at a predetermined distance from the free end of the tubing as shown.
In accordance with the present invention the tubing T is not severed at this cutting station but rather is partially cut at predetermined points along the tubing T as dictated by the length of the tube segments to be formed (see FIG. 2 for a typical tube segment and typical end formation to be provided on such a tube segment.
Clamping means is provided on the tube feeding and cutting machine portion and this clamping means comprises a conventional clamp assembly 18 movable as suggested by arrow 16 to steady the projecting end portion of the tubing while it is partially cut as described above. Clamp assembly 18 can be clamped and released in synchronism with the clamp 12 referred to previously. More particularly the tubing T is fed downstream after such a partial cut, and after these clamps 12 and 18 have been released. The tube segment T 1 is advanced from the position shown in FIG. 1 to the position shown in FIG. 3 by tube gripping means 22 to be described. Tube clamping means 20 is provided adjacent the upstream side of the partial cut C in the tubing T so as to steady the tubing after it has been advanced to the position shown for it in FIG. 3.
The tube gripping device or means 22 provides two functions. First to secure the upstream end portion of the tube segment defined by the partial cut C and the end of the tube segment T 1 . Secondly, the tube gripping means 22 is provided on a horizontally translatable carriage assembly 24 that provides for movement of the gripping device 22 from a upstream or first position illustrated in FIG. 3 to a downstream position illustrated in FIGS. 4, 5 and 6. The movement of the device 22 is under the control of a fluid cylinder 26 that is adapted to move the carriage assembly 24 in the direction of the double ended arrow 28 in FIG. 1.
Downstream motion of the tube segment gripping means 22 from the FIG. 3 position to that illustrated in the other views will sever the tube segment T 1 from the tubing T at the partial cut position C referred to previously and will do so under close control so that the tube segment T 1 remains in axial alignment with the tubing T from which it has been separated even as it is moved downstream as suggested in the drawings.
As suggested in FIG. 4 the space provided between the upstream end of the tube segment T 1 and the downstream end of the tubing T provides a predetermined space for receiving a double end tube forming device 30 that is provided on a cross slide 32 in the machine frame so as to be movable from an inactive position, best shown in FIG. 5, to an active position as suggested in FIGS. 1 and 4. As so constructed and arranged the downstream end of the tubing T and the upstream end of the tube segment T 1 can be simultaneously formed by the end forming tooling as desired, and as suggested generally at the right and left hand end of the tube segment of FIG. 2. Thus, the double tube end forming device 30 of the drawings actually comprises two coaxially arranged tube forming heads that may or may not be identical, but that are operable simultaneously to properly shape the left and right hand ends of each tube segment successively formed in an apparatus in accordance with the method of the present invention.
The actual configuration for these tube forming heads 30a and 30b will be dictated by the desired end configurations of the tube segment and as mentioned previously. Where the ends of the tube segment are to be identically formed the tooling or heads may be identical but such is not necessary in the present invention and differently configured tube ends can be provided simply by changing the heads 30a and 30b in the double tube end forming attachment 30. A hydraulic cylinder 34 is provided to move the double tube end forming attachment 30 between the inactive position shown for it in FIG. 5 and the active position of FIGS. 1 and 4.
As shown in FIGS. 7 and 8 each head, 30a and 30b respectively, comprises an axially reciprocable ram that is movable into the adjacent end of the clamped tubing, or tube, to provide the desired tube end shapes as suggested in FIG. 2. The head 30a cooperates with the tube clamping means 20 to shape the downstream or right hand end of tube T. The head 30b cooperates with the tube gripping means 22 to shape the upstream end of the tube segment T 1 .
More specifically, the head 30a includes a fluid actuator for moving a ram 31a from its FIG. 7 position into the end of the tube T as shown in FIG. 8. A fixed die surface is defined by the clamping means 20 as shown at 21a, and the ram 31a includes an annular tube constraining portion 33a that moves with the ram to retain the tube diameter at T O (See FIG. 2) as the flange T a is formed between die 21a and the left hand end of this annular portion 33a.
The head 30b includes a fluid actuator for moving a ram 31b from its FIG. 7 position into the end of the tube segment T 1 as shown in FIG. 8. A fixed die surface is defined by the tube gripping means 22 as shown at 22a. The gripping means 22 operates horizontally to clamp and release the tube segment so that the fixed die is actually made in two halfs. This is also true of the die associated with the clamping means 20, although the latter moves vertically to clamp and release the tubing T. An annular tube flaring portion 33b of the ram 31b shapes the outside of the tube end as suggested at T b in FIG. 2. As so constructed and arranged two tube ends are formed simultaneously as a result of separating each tube segment from the supply of tubing T and positioning said tube segment T 1 in a structure 22 that supports the tube segments T 1 in alignment with, and in precisely spaced relationship to the end of the supply tubing T.
Finally, once the ends of the tubing T and tube segment T 1 have been appropriately formed gripping means 22 releases the tube segment T 1 for transfer downstream for further processing on a take away conveyor 36 provided for this purpose in the horizontal transfer table or carriage assembly 24. The stroke 28 of the carriage assembly 24 can be adjusted to accommodate different lengths of the tube segments to be fabricated. A horizontally extending bed or frame 40 is provided to slidably support the clamping means 20 and carriage assembly for the gripping means 22 as well as the cross slide 32 for the double end tube forming attachment 30 referred to previously. All of the above are positioned by means of a hydraulic motor (not shown) coupled to the end of lead screw 42 so as to preposition the above described apparatus relative to the cutoff station thereby accommodating any length tube segment to be formed in accordance with the apparatus and method of the present invention.
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A continuous supply of tubing is fed intermittently into a work station. Partial cuts are made at periodic intervals by a cutoff head that operates in timed relation with tube clamping device. Tube gripping device then pulls on the end portion or segment to position it precisely downstream of and in alignment with the freshly cut tubing end. A double tube end forming device moves in between the downstream end of the tubing and the upstream end of the tube segment. This device has tube end forming heads that include tooling for suitably shaping both these ends simultaneously.
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FIELD OF THE INVENTION
The present invention relates generally to polymers of brominated styrene, and more particularly to methods for the solventless bulk polymerization of brominated styrenes.
BACKGROUND OF THE INVENTION
A variety of polymers of brominated styrene are known to the art. These brominated polystyrenes are commonly used as flame retardant additives, and are produced by one of two basic methods--the bromination of polystyrene or the polymerization of bromostyrene monomers.
In general, the materials made by the two production methods are not equivalent. For example, bromination of polystyrene will result in undesirable side chain halogenation, causing a reduction in thermal stability or requiring expensive treatment to remove the more labile bromine atoms. Polymers prepared by the polymerization of bromostyrene do not have undesirable side chain halogenation, and are preferred for their relatively greater thermal stability.
Not only do the two methods of preparing brominated polystyrenes provide different end products, there are also numerous disadvantages inherent to the bromination of polystyrene approach. First, such methods require that the polymer be solubilized, necessitating isolation and purification procedures that may add significantly to production costs. Also, because the product is recovered from solution, the final product will be a dusty powder unless some type of compaction step is included at additional cost. Similarly, unless a post-production compounding step is used, the introduction of co-additives is limited to dry blending with other powders.
A more significant disadvantage of the bromination of polystyrene method is that the brominated polystyrenes produced are limited to copolymer compositions and molecular weights that are readily available. In addition, the products must be structures that are stable to, and will not interfere with, the bromination process.
The polymerization of bromostyrene has several advantages over the bromination of polystyrene. As mentioned, it provides a more thermally stable product because side chain halogenation is avoided. Also, this method can be used to produce a continuum of molecular weights and bromine contents not otherwise available. Further, the polymerization can be accomplished without the use of solvents, and is readily adaptable to more economical continuous production processes. In addition, a broad spectrum of copolymer compositions may be produced simply by adjusting the monomer feed. Finally, production of convenient non-dusting pellets (with the option of incorporating auxiliary additives) is a natural by-product of the inventive polymerization process, and may be provided at no additional cost.
Nowhere in the literature of bromostyrene polymers is there any indication that the practical bulk polymerization of these monomers to produce a highly brominated compositions has been addressed. One reason for this omission may be the lack of thermal stability of the brominated materials. Conditions that would normally be used to prepare commercial polystyrene (such as flash devolatilization at temperatures approaching 300° C.) would cause thermal breakdown of most brominated materials, and product discoloration and equipment corrosion would result. Processes using solution and emulsion techniques avoid any possibility of decomposition, even though they are at an economic disadvantage.
A need therefore exists for improved methods of continuously polymerizing bromostyrenes. In particular, a need exists for a method of polymerizing bromostyrenes without the need of solvents and their associated disadvantages. A need also exists for a method of polymerizing bromostyrenes in which the reaction is run to a high degree of completion in a relatively brief period of time. The present invention addresses these needs.
SUMMARY OF THE INVENTION
Briefly describing one aspect of the present invention, there is provided a process for the solventless polymerization of brominated styrenes, comprising the steps of: (a) blending monomers of brominated styrenes with a polymerization initiator; (b) feeding the monomer/polymerization initiator mix into a prepolymerizer wherein the monomers begin to polymerize; and (c) feeding the monomer/polymerization initiator mix and the partially polymerized bromostyrene into a screw-type extruder to drive the polymerization to a high degree of completion in a short period of time. Optionally, the monomers may be preheated before mixing with the initiator, or a heater may be included in the prepolymerizer. Also, a second initiator may be used to facilitate polymerization in the extruder reaction zone.
One object of the present invention is to provide a continuous process for producing brominated styrene homo- and copolymers, wherein the process uses an extruder for at least a portion of the polymerizations.
A further object of the present invention is to provide a screw-type extruder effective for providing a high degree of conversion from monomer to polymer while maintaining an unexpectedly high molecular weight.
A further object of the present invention is to provide an improvement to the basic polymerization process in which the early stages of the polymerization are carried out in a prepolymerizer which may optionally be preceded by a preheater.
It is also an object of the present invention to provide an improved polymerization process in which the free radical source for the prepolymerizer is selected so as to provide rapid initiation at temperatures below 100° C.
Another object of the present invention is to provide an improved polymerization process in which desired additives may be introduced continuously into the brominated polymer during polymerization, thereby avoiding the expense of a separate compounding step.
An additional object of the present invention is to provide polymers that contain about 50% or more by weight of brominated styrene and that are useful as flame retardant additives.
A further object of the present invention is to provide a flame retarding polymer comprised predominantly of brominated styrene and having an APHA solution color of less than 500 following heat ageing for eight hours at 243° C. in a test tube.
Additional objects and advantages of the present invention will be apparent from the following description of preferred embodiments.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of one screw extruder used in the processes of the present invention.
FIG. 2 is a schematic diagram of a second screw extruder used in the processes of the present invention.
FIG. 3 is a schematic diagram of a third screw extruder used in the processes of the present invention.
FIG. 4 is a schematic diagram of a fourth screw extruder used in the processes of the present invention.
FIG. 5 is a diagram of a prepolymerizer used in one preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to preferred embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the described embodiments, and such further applications of the principles of the invention as illustrated therein, being contemplated as would normally occur to one skilled in the art to which the invention pertains.
As briefly described above, the present invention provides a process for the continuous bulk polymerization of brominated styrene monomers without the need for hazardous or costly solvents. The invention utilizes an extruder as a reaction pot to maintain a very short reaction time while controlling the potentially damaging exotherm. Either a single screw or twin screw extruder may be utilized, with the twin screw design being preferred for reasons of higher productivity, better mixing and the ability to take the reaction to a higher degree of completion.
In the extreme, the entire reaction may be carried out in the extruder, using an initiator to accelerate the polymerization. The initiator is conveniently blended into the monomer with the mixture then being fed into the extruder throat. Optionally, a second addition of monomer plus initiator can be made at a point several barrels downstream from the throat. The advantage of this is an increase in productivity; the slower continuous feed at the throat acts as a rear seal for the screw, allowing the faster second feed to be injected under pressure. This avoids the delay of having to wait for the rotating screw elements to carry away low viscosity monomer from the feed throat.
The screw design of the extruder of the present invention is based on the need to control the reaction by subdividing the polymerization into a series of reaction zones. As a comparative example, the extruder might be designed to have only one reaction zone. Such an extruder might be considered to be a plug flow reactor in which the first barrels are used to heat the monomer to polymerization temperature. The middle sections would then contain the highly exothermic runaway polymerization, and the end barrels would further reduce monomer content. Deficiencies flowing from this design include the inability to control temperature in the middle sections, as well as the inability to take the reaction to a high degree of completion. The inability to control temperature in the middle sections allows excessive temperatures to occur during the major portion of the reaction, eliminating the option of producing higher molecular weight versions of the product and possibly causing thermal degradation. The inability to take the reaction to a high degree of completion is probably caused by inadequate monomer mixing.
The preferred embodiments of the present invention avoid the aforementioned problems by spreading the reaction out over a larger number of barrels. This is accomplished by selecting a screw design comprising at least three reaction zones. Each of the zones is characterized by three types of elements in the following order: (1) forward conveying, (2) neutral mixing, (3) flow impeding. The forward conveying elements can be of a normal flighted feeding type, conveying kneading type, or similar design intended to move material through the barrel toward the die. The neutral mixing section may consist of neutral kneading blocks, turbine blades or other designs that will mix materials but have little or no conveying effect. The last element type is a flow impeding design such as a reverse pumping element or a constricting element--sometimes referred to as a blister--which partially blocks the barrel, causing back pressure.
The series of reaction zones may be preceded by a number of forward conveying elements. These will help to move material away from the throat, into the reaction zones, and serve to form a rear seal for the screw. The reaction zones may also be followed by forward conveying elements in order to move product away from the reaction zones and to develop the pressure required to force product through the die.
It has been discovered that the number of required reaction zones is determined in part by the size (screw diameter) of the extruder. For example, in a 57 mm machine acceptable results were achieved with just five reaction zones. In scaling up to a 70 mm extruder however, acceptable results required seven zones, and significant improvements were obtained with a nine-zone design.
The initiator for the extruder phase of the reaction may be selected from free radical generators well known to the industry. The preferred initiators have a reactivity such that they cause rapid polymerization of bromostyrenes to begin at temperatures above approximately 75° C. Examples of initiators that may be used to begin polymerizations within the extruder include
dicumyl peroxide
di-t-butyl peroxide
2,5-dimethyl-2,5-bis(t-butylperoxy)hexane
benzoyl peroxide
cumene hydroperoxide
t-butyl hydroperoxide
The initiators are normally used at loadings from 0.05% to 5% on weight of monomer with levels from 0.1% to 2% being typical. Further, blends of free radical generators may be employed with the intent of one initiating most of the polymer formation at a lower temperature to maximize molecular weight, and a second more stable one becoming active towards the end of the reaction in order to reduce levels of unreacted monomer.
In one preferred embodiment, the extruder is used to complete the reaction which was begun in a prepolymerizer. Several designs would be suitable as a prepolymerizer. In the broadest sense, a prepolymerizer is a vessel through which monomer or mixtures of monomers are continuously introduced while a mixture of monomer and polymer is continuously removed. It is preferred that the contents of the vessel be agitated in some fashion to prevent localized areas of high polymer content. Means for heating the contents are desirable, but are not required if a preheater is used. Examples of suitable prepolymerizers include stirred tank reactors, static mixing tubes, and even other extruders.
A low temperature, free radical generator is used to initiate the reaction when a prepolymerizer is utilized. The initiator may be selected from peroxides, azo compounds, and other free radical generators known to the industry. Preferred initiators have a reactivity such that they cause rapid polymerization of bromostyrenes at temperatures below approximately 100° C. This reactivity is normally expressed in terms of the half life temperature. The initiators of the present invention are selected such that at least half of the initiator has decomposed when held for 1 hour at 100° C. Examples of products meeting this requirement are
benzoyl peroxide
t-butylperoctoate
t-butylperoxypivalate
decanoyl peroxide
di(2-ethylhexyl) peroxydicarbonate
2,2'-azobis (2,4-dimethylvaleronitrile)
2,2'-azobis(isobutyronitrile)
The most preferred is 2,2'-azobis(2,4-dimethylvaleronitrile). The low temperature initiator is used at levels of from about 0.05% to 5% by weight of the monomer, with levels from 0.1% to 2% being preferred.
In addition, accelerants or promoters may be used to reduce the half life temperature (increase the reactivity) of an initiator. For example, the combinations of benzoyl peroxide/dimethylaniline and methylethylketone peroxide/cobalt soaps are well known to provide low temperature reactivity.
The monomer may be 10% to 95% converted to polymer upon exiting the prepolymerizer, with a range of 40% to 95% being preferred. Upon entering the extruder the addition of a high temperature initiator or blend of initiators may be desirable to complete the polymerization. The initiator may be added along with the monomer/polymer mixture, or may be injected several barrels downstream. Examples of suitable free radical generators are listed above (1 hour half lives above 75° C.) with 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane being most preferred.
The brominated monomers may have the general formula ##STR1## where R1=H, CH 3 ; R2=H, C 1-4 alkyl; x=1 to 5.
Preferred monomers are those in which R1=R2 H. The most preferred monomer is dibromostyrene (DBS). As produced by Great Lakes Chemical Corporation DBS normally contains about 15% monobromostyrene and about 3% tribromostyrene by weight. In one preferred embodiment then, the bromostyrene monomers comprise from about 1% to about 20% monobromostyrene, from about 0.5% to about 10% tribromostyrene, and from about 70% to about 98.5% dibromostyrene.
The monomer may also contain various storage stabilizers such as phenols or compounds of sulfur, nitrogen and phosphorus known to the industry to inhibit premature polymerization. Optionally, the stabilizer may be removed prior to polymerization by water washes or by passing the monomer through a bed of activated carbon, silica, alumina or the like. Although water washes are not required, they provide the benefit of producing faster and more consistent reactivity.
One advantage of the inventive process is the ability to produce a variety of molecular weight polymers within a particular piece of equipment by making only minor changes. It is very desirable and useful to offer these different product variations. For example, a low molecular weight brominated polystyrene is known to provide better impact strength in rubber modified polystyrene, while the higher melt viscosity of the high molecular weight versions is preferred for processing characteristics with certain nylons.
The modification of molecular weight may be accomplished through several different approaches. Traditional chain transfer agents such as compounds of sulfur or aliphatic halides may be added to the monomer prior to the start of the reaction. For example, 1-dodecanethiol or bromotrichloromethane are known to be very effective. A second approach is to simply increase the loading of initiator used to begin the polymerization. Higher concentrations of active chain initiators increase the competition for available monomer and promote certain chain terminating reactions. Both of these approaches will shorten the average chain length. A third way to reduce molecular weight is to conduct the polymerization at a higher temperature. This will also increase the concentration of active initiators, as well as increase the probability of chain terminating reactions occurring before chains have grown to high molecular weight.
Prior to polymerization, a minor amount of other reactive unsaturated monomers can be mixed into the brominated styrene for the purpose of additional property modification. Examples of modifications that might be desirable include changes in color, clarity, lubricity, compatibility, melt viscosity, softening point, thermal stability, ultraviolet stability, viscoelastic behavior, polarity, biodegradability and static charge dissipation. Examples of potential reactive comonomers are maleic anhydride, styrene, substituted styrenes such as α-methylstyrene and chloromethylstyrene, acrylonitrile, methylmethacrylate, acrylic acid, inethacrylic acid, butadiene and acrylamide.
Because the polymers used in the process are molten thermoplastics during the extruder stage, it is an advantage that nonreactive additives may be incorporated during the process without the expense of a separate compounding step. Metered addition of materials may be accomplished at the feed throat or via a "crammer feeder" attached to any of the extruder barrels while polymerization is being completed in the extruder. The product exiting the extruder is therefore a very desirable package of additives in a homogeneous pellet form, produced without the expense of separate blending and compounding steps.
Examples of additives that might be included in the package include antioxidants, ultraviolet absorbers, antistatic agents, pigments, dyes, nucleating agents, fillers, slip agents, lubricants, antiblocking agents, plasticizers, tougheners and antimicrobials. Further, supplemental flame retardants may be incorporated into the package. These may include nonhalogenated materials such as Sb 2 O 3 , Sb 2 O 5 , Bi 2 O 3 , MoO 3 , NH 4 NO 3 , trityl compounds, 2,3-dimethyl-2,3-diphenylbutane, peroxides, and various phosphorous and/or nitrogen containing materials. The bromostyrene polymers may also include other halogenated flame retardants which could be used to increase the overall halogen content, improve efficiency or reduce dripping during combustion. Examples of potential halogenated additives include
decabromodiphenyloxide
octabromodiphenyloxide
bis(tribromophenoxy)ethane
decabromodiphenylethane
bisimide of tetrabromophthalic anhydride and
ethylenediamine
Reference will now be made to specific examples using the processes described above. It is to be understood that the examples are provided to more completely describe preferred embodiments, and that no limitation to the scope of the invention is intended thereby.
EXAMPLES
In the following examples molecular weights are given as "M PS ", or peak molecular weight versus polystrene standards. This is determined by gel permeation chromatography in which the peak retention time of the bromostyrene polymer is equated with the molecular weight of a polystyrene standard having the same retention time.
EXAMPLE 1
Example 1 demonstrates the use of a single screw extruder as a continuous prepolymerizer.
A Brabender Prep Center single screw extruder (L/d=25/1, all zones at 150° C., 40 rpm's) was fed DBS containing 0.125% t-butylperoxy-2-ethylhexanoate at a rate of approximately 5 pounds per hour. The material exiting the die was collected on dry ice to quench the reaction and was found to contain 20.4% residual monomer, with the polymeric portion having a molecular weight M PS of 81,900.
EXAMPLE 2
A heated static mixing tube was successfully used as a continuous prepolymerizer.
Six feet of 0.5 inch diameter stainless steel static mixing tube was jacketed within a 2 inch cast iron pipe. The area between the tube and the pipe was filled with oil which was continuously recirculated to an external heater. With the oil temperature held at approximately 165° C., dibromostyrene containing 0.03% t-butyl peroxy-2-ethylhexanoate (also known as t-butylperoctoate) was pressured through the static mixer at an average rate of 93 grams/minute. The product was collected as in Example 1. The product had an average molecular weight of 77,500, and contained 21% unreacted monomer.
EXAMPLE 3
A single screw extruder was used to complete the reaction begun in a prepolymerizer.
Partially converted dibromostyrene prepared using a single screw extruder as in Example 1 was collected and ground. A blend of 0.5 parts di-t-butylperoxide per 100 parts of monomer/polymer mixture was continuously fed into the same single screw extruder of Example 1, but with a hotter temperature profile. Settings of 210°, 210°, 220°, 220°, and 230° C. from throat to die were maintained. At a screw speed of 60 rpm's the material going through the extruder had an estimated residence time of 55 seconds and was processed at a rate of 33 pounds per hour. Before processing the material had an M PS of 81,400 and contained 13.4% monomer. After the reaction, the molecular weight was 70,000 and the monomer was reduced to 0.5%. Accordingly, it can be seen that the prepolymerizers of Example 1 or 2 could be arranged in tandem with the extruder of Example 3 to provide a continuous process.
EXAMPLE 4
High molecular weight polydibromostyrene was prepared using a 30 mm twin screw extruder as the only reactor.
A Werner & Pfleiderer twin screw extruder (Model ZSK-30, L/d=44/1) was continuously fed dibromostyrene/peroxide mixtures at two points simultaneously. The temperature profile was maintained at 160°, 155°, 185°, 205°, 205°, 220°, 230° and 240° C. from throat to die while the screw speed was set at 400 rpm's. The compositions and rates of feed were:
______________________________________FEED ADDITIVES, FEED RATE,POINT FEED % OF MONOMER LBS/HR______________________________________Throat DBS 0.125% t-butylperoxide 10.5Port DBS 0.125% di-t-butylperoxide + 23.1 0.0625% t-butylperoctoate TOTAL 33.6______________________________________
The feed throat was located in the first barrel and the injection port was approximately one-fourth of the way towards the die. Experimentation determined that 30 to 35 lbs/hr was the maximum effective feed rate. Increasing monomer flow at either point resulted in flooding of the throat.
A clear amber thermoplastic material was collected at the die. Analysis showed that it had an average molecular weight of M PS =72,700 with a residual monomer content of 0.53%. Accordingly, it can be seen that the polymer could be continuously produced at a reasonable rate using only a twin screw extruder.
EXAMPLE 5
Low molecular weight polydibromostyrene was also prepared in the twin screw extruder.
Using the same extruder as in Example 4, but with different temperature settings and feed composition, low molecular weight polydibromostyrene was continuously produced. Zone temperatures averaged 155°, 160°, 155°, 155°, 155°, 220°, 155° and 170° C. Screw speed remained at 400 rpm's. The compositions and rates of feed were:
______________________________________FEED ADDITIVES, FEED RATE,POINT FEED % OF MONOMER LBS/HR______________________________________Throat DBS 1.0% t-butylperoctoate + 11.0 1.0% 1-dodecanethiolPort DBS 0.5% t-butylperoctoate + 23.9 1.0% t-butylperbenzoate + 1.0% 1-dodecanethiol TOTAL 34.9______________________________________
Analysis of the product showed that it had an average M PS of 8,600 with a residual monomer content of 0.45%. This material has a glass transition temperature 35° C. lower than that of the polymer in Example 4, indicating that the two materials are substantially different. Both can be continuously produced in the same equipment however, demonstrating the flexibility of the process.
EXAMPLES 6, 7, 8 and 9
The importance of the extruder screw design was demonstrated in larger scale production.
A Werner & Pfleiderer Model ZSK-70 twin screw extruder was configured similarly to that used in Examples 4 and 5. It had an L/d=44/1 and was fitted with an injection feed port. Typical zone temperatures were 160°, 160°, 160°, 160°, 160°, 190°, 220°, 230° and 215° C. while the screw speed was maintained at 400 rpm's. Monomer feed information is shown below.
______________________________________FEED ADDITIVES, FEED RATE,POINT FEED % OF MONOMER LBS/HR______________________________________Throat DBS 0.25% t-butylperoctoate 145Port DBS 0.20% t-butylperoctoate + 285 0.15% cumenehydroperoxide TOTAL 430______________________________________
Using these conditions, four screw designs were evaluated for their ability to produce the highest molecular weight and the lowest residual monomer. Schematics of the designs are shown in FIGS. 1 through 4. Typical values for the material produced with each design are shown below.
______________________________________ RESIDUAL SCREW MONOMER, MOLECULAREXAMPLE DESIGN % WEIGHT, M.sub.PS______________________________________6 (Comparative) 1 2.6 48,0007 (Comparative) 2 0.5 43,0008 (Comparative) 3 0.7 50,0009 4 0.7 62,000______________________________________
The screw design in Example 6 contained 5 reaction zones. This did not provide adequate control of the reaction, spreading it out over just a long enough section to provide only medium molecular weight polymer. And with only 5 mixing areas the monomer content was still too high at the vented barrel to permit vacuum devolatilization without foaming. The design in Example 7 increased the number of reaction zones from 5 to 6 by adding a small section of neutral turbine mixers. This reduced the monomer to the point at which a vacuum could be applied, but molecular weight was still in the medium range. In Example 8 the number of reaction zones was increased from 6 to 7, producing acceptable residual monomer and some improvement in molecular weight. However, it was not until Example 9, increasing the number of reaction zones to nine, that high molecular weight and low residual monomer were achieved.
EXAMPLE 10
A supplemental flame retardant was incorporated into polydibromostyrene during continuous production.
Using the same extruder as in Example 4, decabromodiphenyloxide (DBDPO) was continuously introduced into the reaction mixture to produce a blend of flame retardants in a single step. The following materials were used:
______________________________________ FEEDFEED ADDITIVES, RATE,POINT FEED % OF MONOMER LBS/HR______________________________________Throat DBS 0.20% t-butylperoctoate 10.6Throat DBDPO -- 12.3Port DBS 0.185% t-butylperoctoate + 24.5 0.155% cumenehydroperoxide TOTAL 47.4______________________________________
The temperature profile was maintained at approximately 140°, 150°, 180°, 180°, 200°, 220°, 230° and 240° C. from throat to die. Screw speed was 400 rpm. The polymeric portion of the product had an M PS of 59,800, while the overall composition had a monomer content of 0.88%. The product had a calculated bromine content of 66% (compared with 60% for the neat homopolymer). Accordingly, less of the blend would be required as a flame retarding additive, making it a more efficient and valuable product while being produced at no greater of a manufacturing cost than the homopolymer itself.
EXAMPLE 11
An inorganic synergist was also incorporated during continuous polymerization.
Using essentially the same reaction conditions as in Example 10, antimony trioxide was continuously metered into the extruder throat along with monomer. Non-dusting plastic pellets containing high levels of bromine and antimony were produced. The ability to provide both components in a single package--as well as the ability to eliminate the need for the customer to handle powdered Sb 2 O 3 --is a significant advantage of the present invention.
EXAMPLE 12
A prepolymerizer was used to increase the production rate of DBS homopolymer.
A prepolymerizer was constructed as shown in FIG. 5. In essence it was an elongated stirred tank reactor consisting of a 2 inch jacketed pipe containing a full length stir shaft fitted with a variety of blade types. Heating/cooling was accomplished by pumping oil of the desired temperature through the jacket. Monomer plus peroxide was continuously pumped into the bottom of the reactor and overflowed from the top directly into the twin screw extruder described in Example 4. The temperature profile of the extruder was 200°, 210°, 210°, 210°, 210°, 220°, 220° and 220° C. with a screw speed of 400 rpm's. Oil temperature to the prepolymerizer was 145° C. A high temperature peroxide was injected neat into the extruder to complete the reaction.
______________________________________ FEEDFEED ADDITIVES, RATE,POINT FEED % OF MONOMER LBS/HR______________________________________Prepolymerizer DBS 0.25% t-butylperoctoate 71.4______________________________________
The partially converted material exiting the prepolymerizer contained 14 to 20% monomer, but after passing through the extruder this was reduced to 0.82%. Molecular weight averaged an M PS of 49,700. The productivity of this design represents a two fold increase over that seen in Example 4 where the prepolymerizer was not used.
EXAMPLE 13
A preheater and a low temperature initiator were used to further increase productivity and to reduce the peak temperature.
The equipment in Example 12 was modified by adding a preheater to the system directly before the prepolymerizer. The preheater consisted of a 3 ft. long single pass stainless steel heat exchanger using recirculated tempered water as the heat source. Dibromostyrene monomer was passed through the preheater, warming it to about 70° C. before it entered the prepolymerizer. The low temperature initiator was injected into the monomer just before it entered the prepolymerizer. Oil temperature to the prepolymerizer was reduced to 135° C. A high temperature peroxide was injected neat into the extruder to complete the reaction.
______________________________________ FEEDFEED ADDITIVES, RATE,POINT FEED % OF MONOMER LBS/HR______________________________________Prepolymerizer DBS 0.1% 2,2'-azobis(2,4- 85 dimethylvaleronitrile)Port -- 0.5% 2,5-dimethyl-2,5- bis(t-butylperoxy)hexane______________________________________
The polymer produced under these conditions had an M PS of 64,000 with a residual monomer of 0.35%.
The introduction of the preheater and low temperature initiator had several beneficial effects. For example, production rates were significantly increased over the 71.4 lbs/hr of the previous Example. This was accomplished by preheating the materials to near reaction temperature before entering the prepolymerizer, making the prepolymerizer more efficient.
Also, the peak temperature within the prepolymerizer was reduced. The higher temperature peroxide used in Example 12 required that the reactants be heated to approximately 145° C. to provide rapid polymerization. The exothermic polymer formation resulted in peak temperatures as high as 280° C. This is not desirable since low levels of thermal decomposition will occur, lowering product quality. The initiator of the current Example caused the reaction to begin at a lower temperature. Since the heat of polymerization is independent of the temperature at which the reaction begins, the lower initiation provided a peak exotherm of around 200° C., well below the point of thermal decomposition.
Finally, molecular weight was increased. Because of the factors described above, most of the polymer is formed at a lower temperature where chain termination reactions are less prevalent.
EXAMPLE 14
A copolymer of dibromostyrene was prepared using the design of this invention.
A mixture of 60% dibromostyrene/30% styrene/10% acrylic acid by weight and containing 0.1% 2,2'-azobis(2,4-dimethylvaleronitrile) was processed through the equipment of Example 13. High temperature peroxide was injected into the extruder to complete the reaction. The product was a thermoplastic material with a calculated bromine content of 36%, and was useful as a flame retardant additive in polar resin systems.
EXAMPLE 15
The thermal stability of a DBS homopolymer, PDBS, was compared with that of a polymeric material obtained by bromination of polystyrene (BrPS).
A sample of each material was placed in a test tube which was then inserted into a heating block maintained at 243° C. The contents were held at temperature and exposed to air for 8 hours, after which the samples were cooled and removed by breaking away the glass. Colors of the heat treated materials were determined by dissolving them in toluene and comparing them with APHA standards. The PDBS demonstrated significantly less color formation, indicating less thermal decomposition.
______________________________________Sample APHA Color (lg/50 ml toluene)______________________________________PDBS 400BrPS >500______________________________________
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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A process for the solventless polymerization of brominated styrenes includes blending monomers of brominated styrenes with a polymerization initiator, feeding the monomer/polymerization initiator mix into a prepolymerizer wherein the monomers begin to polymerize, and feeding the monomer/polymerization initiator mix and the partially polymerized bromostyrene into a screw-type extruder to drive the polymerization to a high degree of completion in a short period of time. Optionally, the monomers may be preheated before mixing with the initiator, or a heater may be included in the prepolymerizer.
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TECHNICAL FIELD
[0001] Interferometric measuring systems with optical probes as can be arranged for the practice of our invention provide for measuring localized surface features, geometric surface forms, and overall dimensions. The invention is particularly applicable to the measurement of cylindrical, conical, and flat surfaces whose roughness approaches tolerances for geometric form as well as to the measurement of test pieces having multiple surfaces requiring individual or comparative measurements.
BACKGROUND
[0002] Tolerances for many precision manufactured components continue to go beyond the capabilities of conventional contact measuring techniques. Optical measuring techniques, particularly those using interferometric mechanisms, provide for measuring with much greater precision. However, the roughness of the surfaces under test often exceeds one-half of the wavelengths used in conventional interferometers (i.e., wavelengths in the visible or near-infrared range). Surface features larger than one-half the measuring wavelength cannot be unambiguously measured with conventional interferometers. Longer wavelengths can be used, but lasers for producing such longer wavelengths are less common and more expensive than those available for producing wavelengths in the visible or near-infrared range.
[0003] Manufactured components that include multiple surfaces can require measurements of their individual surface forms (e.g., roundness and straightness) as well as measurements of relationships between their surfaces (e.g., runout and perpendicularity). Measuring each of the surfaces individually with setups or recalibrations between the different measurements is time consuming and can make comparisons difficult.
SUMMARY OF THE INVENTION
[0004] Our interferometer in one or more of its preferred embodiments provides for measuring multiple surfaces with a compound optical probe. Sub-test beams emitted from the probe separately measure the multiple surfaces. A confocal optical system distinguishes the measurements between the surfaces. Each of the sub-test beams can be composed of two fundamental wavelengths of light from different interferometers. Combined, the two interferometers greatly increase the dynamic range of measurement for measuring rough surfaces with conventional lasers.
[0005] An exemplary interferometer for measuring multiple surfaces of a test piece in accordance with our invention includes a test arm and a reference arm that convey test and reference beams along different but ultimately interconnected paths. A beamsplitter within the test arm separates the test beam into first and second sub-test beams. A focusing optic of the confocal optical system within the test arm focuses the first and second sub-test beams to different points of focus. A compound probe also within the test arm conveys the first and second sub-test beams to the different points of focus.
[0006] Preferably, each of the sub-test beams is intended for measuring a different surface of the test piece at normal incidence. As such, the principal axes of the sub-test beams are oriented normal to their incident test surfaces, which can be oriented in different directions. Directional optics within the probe direct the sub-test beams to their points of focus at their intended orientation. Additional sub-test beams can be split from the test beam within the test arm for measuring more than two surfaces of the test piece, each being directed to a point of focus at normal incidence to a different test surface.
[0007] The test surfaces are preferably measured individually in succession. An actuator relatively moves the probe with respect to the test piece between two or more measuring positions. In a preferred embodiment, the actuator is movable between two positions for measuring two surfaces of a test piece. At a first of the positions, the point of focus of the first sub-test beam is positioned on the first surface of the test piece and the point of focus of the second sub-test beam is positioned off both the first and second surfaces of the test piece. At a second of the positions, the point of focus of the second sub-test beam is positioned on the second surface of the test piece and the point of focus of the first sub-test beam is positioned off both the first and second surfaces of the test piece. Similarly, at a third or higher measuring position, the additional points of focus are positioned in turn on other of the test piece surfaces while the remaining points of focus are positioned off of all the test surfaces.
[0008] A detection system detects an interference signal between the reference beam and the first sub-test beam when the probe is located at the first position and detects an interference signal between the reference beam and the second or higher sub-test beam when the probe is located at the second or higher position. The detection system is preferably arranged in conjunction with a confocal optical system that excludes from detection light that is not focused on one of the test surfaces. An imaging optic of the confocal optical system can be used to refocus the sub-test beams conjugate to their points of focus of the focusing optic. A limited aperture size near the focus of the imaging optic limits a depth of focus through which light is effectively collected by a detector at the end of the confocal optical system. If any of the test surfaces are located out of focus (e.g., by as few as 10 to 100 microns), little of the reflected light reaches the detector. The aperture size can be limited by locating a stop near the conjugate focal point or by locating a detector of limited dimension near the same point of focus.
[0009] For measuring rough surfaces or surfaces with significant discontinuities, such as surfaces with an average roughness approaching one-half of wavelengths in the near-infrared range, our invention provides laser sources that produce two beams having different fundamental wavelengths of light. Beamsplitters divide each of the different wavelength beams into test and reference beams. Another beamsplitter combines the two different wavelength test beams into a common test beam composed of the two different wavelengths. It is the common test beam that is divided into the multiple sub-test beams, resulting in each of the sub-test beams being composed of the two wavelengths.
[0010] Each of the different wavelength reference beams preferably propagates along respective reference delay lines of the reference arm for controlling the optical path lengths traversed by the two reference beams. Preferably, the two reference delay lines have adjustable optical path lengths to equate optical path lengths between the test and reference arms of the interferometer. The optical path lengths of the test and reference arms can also be equated by incorporating similar path-length adjustments within the test arms.
[0011] The detection system preferably includes first and second arrays of detectors for separately detecting interference between each of the two pairs of test and reference beams. The detectors within each of the first and second arrays are preferably relatively phase shifted for simultaneously detecting a plurality of phase-shifted measurements within each of the first and second pairs of test and reference beams. The simultaneous phase-shifted measurements allow for discerning more accurate phase differences between the test and reference beams at each fundamental wavelength.
[0012] Although accurate, the two individual wavelength measurements produce ambiguous results for surface discontinuities greater than one-half the fundamental wavelengths. Our invention, however, provides a controller that combines information from the first and second arrays of detectors to produce aggregate interference measurements having a sensitivity equated to an effective wavelength significantly longer than either of the two different fundamental wavelengths. The aggregate measurements are useful for measuring surfaces with a roughness exceeding one-half the two fundamental wavelengths.
[0013] The actuator is preferably a part of a relative motion system between the probe and the test piece for measuring a plurality of points on each of the two surfaces of the test piece. Preferably, both the test arm and the reference arm are relatively movable together with the probe with respect to the test piece. The detection system is also preferably mounted together with the test and reference arms and the probe on a multi-axis stage assembly for relative motion with respect to the test piece. A base preferably supports both the test piece and the multi-axis stage assembly for relating motions between the probe and the test piece. A displacement-measuring interferometer preferably measures movements between the multi-axis stage assembly and the base. Information from the displacement-measuring interferometer can be combined with interferometric measurements taken through the probe to compensate for any motion errors of the relative motion system or to resolve remaining phase ambiguities required to obtain absolute measurements.
[0014] Our preferred method of measuring multiple surfaces of a test piece with a scanning interferometer follows the basic interferometric practice of dividing a beam of light into test and reference beams but further divides the test beam into multiple sub-test beams. The multiple sub-test beams are focused to different points for separately measuring different surfaces of the test piece. For measuring a first test piece surface, the point of focus of a first sub-test beam is positioned on the first surface of the test piece while the point of focus of a second or higher sub-test beam is positioned off of their respective measuring surfaces of the test piece. For measuring a second or higher test piece surface, the point of focus of the second or higher sub-test beam is positioned on the second or higher surface of the test piece while the point of focus of the first or other lower sub-test beams is positioned off of their respective measuring surfaces of the test piece. Relative motion between the probe and the test piece is used both (a) to move the points of focus across the test surfaces for measuring a plurality of points on each of the test surfaces and (b) to move the points of focus between the sequential measuring positions.
[0015] At their respective measuring positions, the sub-test beams are retroreflected from their points of focus on the surfaces of the test piece. The retroreflected sub-test beams are preferably refocused together with the reference beam proximate to a detector. Interference signals between each of the sub-test beams and the reference beam are detected separately according to which of the sub-test beams is positioned in focus on one of surfaces of the test piece.
[0016] The refocused light of the sub-test beams is refocused conjugate to their points of focus. A limiting aperture near the conjugate plane excludes light from the sub-test beam that is not focused on one of the surfaces of the test piece. A detector for detecting the refocused light is preferably positioned behind the limiting aperture and arranged to collect only the light that passes through the limiting aperture. Alternatively, a detector with a small active area can be located near the conjugate focal plane to function as a similarly limiting aperture excluding light that focuses before or after the focal plane. The retroreflected test beams could also be refocused through a limiting aperture prior to their recombination with the reference beam remote from the detector.
[0017] While confocal optical techniques can be used to distinguish one surface from another, two-wavelength interferometry is preferably used for extending the range of dynamic measurement to accommodate rough surfaces or surfaces with significant discontinuities. Two beams of coherent light having different fundamental wavelengths are each divided into test and reference beams. The different wavelength test beams are combined in advance of the step of dividing the test beam into multiple sub-test beams so that each of the multiple sub-test beams includes the two different fundamental wavelengths.
[0018] Along the path of retroreflection, the two fundamental wavelengths are re-separated for simultaneously measuring optical path differences between the test and reference beam portions of each of the fundamental wavelengths. The optical path differences expressed by the mechanism of interference provide overlapping measurements of individual points on one or the other of the test surfaces that is in focus. Relative motion (i.e., scanning) of the point of focus across the test surface allows for the accumulation of information describing the surface. Interference information detected from both fundamental wavelengths can be combined to reveal unambiguous measurements over a much wider range extending to one-half of an effective wavelength that is significantly longer than either of the two fundamental wavelengths.
[0019] In addition, the remaining ambiguities of the combined interferometric measurements in two wavelengths can be resolved by measuring from a known point of reference the movements required for positioning the points of focus of the sub-test beams on the surfaces of the test piece. For example, the displacement-measuring interferometer can be calibrated to a master test piece and used to track the further motions required to move the probe into the measuring positions. With the positions of the probe known and the positions of the test surfaces known with respect to the probe, absolute measures of the test surfaces can be made.
DRAWINGS
[0020] [0020]FIG. 1 is a diagram of an exemplary scanning interferometer system in accordance with our invention.
[0021] [0021]FIG. 2 is another diagram showing the layout of one of two different wavelength interferometers that are combined within the scanning interferometer system to increase the range of measurement.
[0022] [0022]FIG. 3 is a greatly enlarged cross-sectional view of a probe in a first position for conveying a first of two focused sub-test beams to one of two internal surfaces of a test piece at normal incidence.
[0023] [0023]FIG. 4 is a greatly enlarged cross-sectional view of the same probe in a second position for conveying a second of two focused sub-test beams to the other of two internal surfaces of a test piece at normal incidence.
DETAILED DESCRIPTION
[0024] An exemplary scanning interferometer system 10 shown in FIG. 1 includes a compound probe 12 for measuring a test piece 14 having multiple internal surfaces. The compound probe 12 is mounted on a multi-axis stage assembly 16 , and the test piece 14 is mounted on a rotary chuck 18 . A base 20 supports both the multi-axis stage assembly 16 and the rotary chuck 18 for relating relative motions between the compound probe 12 and the test piece 14 .
[0025] The multi-axis stage assembly 16 is preferably translatable in two orthogonal directions X and Z via mechanical crossed roller bearing stages 16 ′ and 16 ″ driven by respective motor actuators 22 and 24 . Both of the motor actuators 22 and 24 are preferably brushless, slotless DC motors with integral encoders. The compound probe 12 is moved by the multi-axis stage assembly 16 along a desired motion profile by conventional control electronics 26 for the motor actuators 22 and 24 under the programmable direction of a microcomputer 28 .
[0026] Since the stage motion is neither perfectly smooth nor straight, a three-axis displacement-measuring interferometer 30 is used to monitor the motion. Three measurement arms 32 , 33 , and 34 of the displacement-measuring interferometer 30 are shown for monitoring translational motions in the two orthogonal directions of stage motion X and Z and a rotational motion about an axis extending in a third orthogonal direction. The two translational motions are measured by the measurement arms 32 and 33 or 34 . The rotational motion is measured by differential measures between the measurement arms 33 and 34 . The measurement arms 32 , 33 , and 34 are preferably connected to the stage assembly 16 by mirrors 36 , 37 , and 38 constructed from a low-expansion glass. The light source for the displacement-measuring interferometer 30 is preferably a frequency-stabilized helium-neon laser (not shown). The displacement-measuring interferometer 30 measures errors in straightness and yaw in addition to displacement errors of the stage motions. This error data is recorded to remove stage motion errors from probe profile measurements.
[0027] The probe 12 is preferably mounted in a kinematic bracket 13 with a magnetic preload that allows the probe 12 to be removed and reinserted or replaced while maintaining the original alignment. The rotary chuck 18 mounting the test piece 14 is preferably a hydraulic expansion chuck rotatable on an air bearing spindle 40 powered by a direct-drive brushless DC motor 42 with an integral high-resolution encoder. Quadrature signals from the spindle encoder are used to clock data acquisition including data from the displacement-measuring interferometer during measurement. Residual tilt and decenter mounting errors can be removed by software analysis of probe measurements.
[0028] The base 20 supporting both the multi-axis stage assembly 16 for the probe 12 and the rotary chuck 18 for the test piece 14 is preferably made of granite and includes a riser (not shown) on which the multi-axis stage assembly 16 is supported. The rotary chuck 18 is mounted in a hole through the base 20 . The granite structure of the base 20 is integrated into a cradle (not shown) supported by a pneumatic isolation frame (also not shown) for increased immunity from external vibration sources.
[0029] Two interferometer modules 50 and 52 are carried by the multiaxis stage assembly 16 . The two interferometer modules 50 and 52 are preferably identical except as required to accommodate different fundamental wavelengths of largely coherent light. Both fundamental wavelengths are preferably within the near-infrared range. For example, the interferometer module 50 can be operated at a wavelength λ 1 of 1550 nanometers (nm), and the interferometer module 52 can be operated at a wavelength λ 2 of 1310 nanometers (nm). Both interferometer modules 50 and 52 are independently capable of measuring smooth parts; but when analyzed together, a combined interference pattern is generated at a much longer effective wavelength λ e capable of measuring rougher surfaces with greater dynamic ranges. The effective wavelength λ e is given as follows:
λ e = λ 1 * λ 2 λ 1 - λ 2
[0030] Substituting the fundamental wavelengths of 1310 nm and 1550 nm yields an effective wavelength λ e of 8460 nm or approximately 8.5 microns (μm). Surfaces with a roughness Rz (comparing five highest peaks to five lowest troughs) in the order of 2 microns (μm) can easily be measured at the effective wavelength λ e of approximately 8.5 microns (μm).
[0031] Although only the interferometer module 50 is illustrated (see FIG. 2), the depicted features are common to both interferometer modules 50 and 52 varying only to accommodate the different fundamental wavelengths λ 1 and λ 2 . For example, both interferometer modules 50 and 52 preferably include a distributed feedback (DFB) solid-state laser 54 as a source of coherent linearly polarized light. The emitted light beam 56 is collimated by lens assembly 58 and reflected by folding mirror 60 on a path through a half-wave retardation plate 62 to a first polarizing beamsplitter cube 64 . Linearly polarized at 45 degrees, part of the light beam 56 passes directly through both the beamsplitter cube 64 and an attached quarter-wave retardation plate 66 as a first reference beam 68 . The remaining part of the light beam 56 is reflected by the beamsplitter cube 64 through another quarter-wave retardation plate 70 as a first test beam 72 , which passes through a shuttered aperture 74 of the interference module 50 .
[0032] A second test beam 76 differing only in fundamental wavelength emerges from the interferometer module 52 . Three folding mirrors 78 , 80 , and 82 orient the two test beams 72 and 76 relative to a dichroic beamsplitter 84 that merges the two test beams 72 and 76 into a combined test beam 86 en route to the compound probe 12 .
[0033] Within the compound probe 12 as shown in FIGS. 3 and 4, the combined beam is reshaped by a focusing optic 88 of a confocal optical system before being split by another beamsplitter cube 90 into two sub-test beams 92 and 94 . Each of the sub-test beams 92 and 94 contains both fundamental wavelengths λ 1 and λ 2 . The focusing optic 88 mounted within the compound probe 12 focuses the two sub-test beams 92 and 94 to different points of focus 96 and 98 . (It is this characteristic that makes the probe 12 a compound probe.) Before reaching its point of focus 98 , the sub-test beam 94 is folded by a prism 100 (a directional optic) that angularly orients the sub-test beam 94 with respect to the sub-test beam 92 . The two sub-test beams 92 and 94 are oriented normal to two internal surfaces of revolution 102 and 104 within the test piece 14 . In the illustrations of FIGS. 3 and 4, the test surface 102 has the form of a cylinder, and the test surface 104 has the form of a truncated cone.
[0034] The two test surfaces 102 and 104 are measured one at a time. A relative motion system, which includes the drive motor actuators 22 and 24 under programmable control, moves the compound probe 12 in the orthogonal directions X and Z to separately trace the expected profiles of the test surfaces 102 and 104 . The drive motor 42 rotates the test piece 14 about a common axis 106 of the internal (test) surfaces of revolution 102 and 104 to provide three-dimensional scans of the surfaces. Although shown angularly related through a particular obtuse angle, the two test surfaces can be relatively oriented through a range of different angles including a right angle where one of the test surfaces is a cylinder and the other is a flat.
[0035] For separately measuring the two test surfaces 102 and 104 , the compound probe 12 is movable between:
[0036] a first position at which the point of focus 96 of the sub-test beam 92 is positioned on the test surface 102 and the point of focus 98 of the sub-test beam 94 is positioned off both test surfaces 102 and 104 (see FIG. 3) and
[0037] a second position at which the point of focus 98 of the sub-test beam 94 is positioned on the test surface 104 and the point of focus 96 of the sub-test beam 92 is positioned off both the test surfaces 102 and 104 (see FIG. 4).
[0038] Within each of the two positions, the compound probe 12 is relatively translated while the test piece 14 is relatively rotated to scan a range of points on one or the other of the test surfaces 102 and 104 .
[0039] During the course of measurement, light retroreflected from the test surfaces 102 or 104 re-enters the compound probe 12 on return paths to the two interferometer modules 50 and 52 . The entire routes of the two test beams 72 and 76 , the combined test beam 86 , and two sub-test beams 92 and 94 are contained within a test arm of our scanning interferometer 10 between the corresponding beamsplitter cubes 64 (only one shown) in the interferometer modules 50 and 52 and the two points of focus 96 and 98 . Exemplary of both test beams 72 and 76 , the test beam 72 re-encounters the one-quarter wave retardation plate 70 in advance of the beamsplitter cube 64 . The two encounters with the one-quarter wave retardation plate 70 have the effect of rotating polarization so that the returning test beam 72 is transmitted rather than reflected by the beamsplitter cube 64 .
[0040] Each of the interferometer modules 50 and 52 contains a working reference arm. The reference beam 68 emerging from the beamsplitter cube 64 is reflected by a folding mirror 108 along a reference delay line 110 , which also includes a compound reflecting prism 112 and a reference module 114 that provides for retroreflecting the reference beam on a return path to the beamsplitter cube 64 . The compound reflecting prism 112 is adjustable along an optical axis in opposite directions A R for matching the optical path length of the reference arm to the optical path length of the test arm. The reference module 114 simulates optics of the compound probe 12 to match the optical experiences of a range of rays surrounding the optical axis between the test and reference arms.
[0041] The optical path lengths of the test and references arms can also be nominally equated by making path length adjustments to the test arm. For example, the interferometer modules 50 and 52 can be adjusted in position on the multi-axis stage assembly 16 with respect to the folding mirrors 78 and 82 to change the physical path lengths traversed by the first and second test beams 72 and 76 .
[0042] The returning reference beam 68 re-encounters the one-quarter wave retardation plate 66 and is reflected rather than transmitted through the beamsplitter cube 64 into alignment with the test beam 72 . A combined test and reference beam 118 emerges from the beamsplitter cube 64 through another one-half wave retardation plate 120 as 45 degree linearly polarized light. An interference filter 122 , which removes unwanted wavelengths, and an aperture stop 124 , which removes stray rays, reduce noise in the combined test and reference beam 118 .
[0043] An imaging optic 126 of the confocal optical system in combination with a cluster of three beamsplitter cubes 130 , 132 , and 134 images the combined test and reference beam 118 onto four detectors 136 , 138 , 140 , and 142 having an incremental 90 degree phase shift among them. Respective points of focus of the imaging optic 126 are preferably conjugate to the focal points 96 and 98 of the sub-test beams 92 and 94 and are preferably coincident with the four detectors 136 , 138 , 140 , and 142 . Each of the four detectors 136 , 138 , 140 , and 142 receives light through a limited aperture size at the focus of the imaging optic 126 . Together, the focusing and imaging optics 88 and 126 function as opposite ends of a confocal optical system that excludes light that does not approach the conjugate points of focus.
[0044] Either the detectors 136 , 138 , 140 , and 142 can be arranged in conjunction with aperture stops of limited size or the detectors 136 , 138 , 140 , and 142 themselves can be of limited size (e.g., 10 to 100 microns) to exclude light at different depths of focus (e.g., 10 to 100 microns depths of focus). Since the focus 96 or 98 of just one of the sub-test beams 92 or 94 is located on one of the test surfaces 102 or 104 of the test piece 14 in each of the two measuring positions, the imaging optic 126 allows for the detection of light from just one of the two sub-test beams 92 or 94 at each of the two measuring positions. Thus, each of the two test surfaces 102 and 104 of the test piece 14 can be separately measured with the compound probe 12 .
[0045] Alternatively, the imaging optic 126 could be located in advance of the beamsplitter cube 64 for refocusing one or the other of the test beams 72 or 76 independently of the reference beam. A limiting aperture, such as a stop, is preferably located near the conjugate focus of the imaging optic 126 for excluding the further propagation of light that is not retroreflected from one of the points of focus 96 or 98 on one of the test surfaces 102 or 104 .
[0046] The clustered beamsplitter cubes 130 , 132 , and 134 are separated by retardation plates 146 and 148 to support 90 degree phase shifts among the four detectors 136 , 138 , 140 , and 142 . The data acquisition system timed to the incremental rotation of the test piece 14 simultaneously acquires data from all four detectors 136 , 138 , 140 , and 142 in each of the two interferometer modules 50 and 52 along with data from the three-axis displacement-measuring interferometer 30 for generating instantaneous measurements at individual points on one or the other of the test surfaces 102 or 104 . The phase-shifted data allows for the more precise identification of phase differences between the combined test and reference beams, and the displacement data relates data points with improved accuracy along the measured profiles of the test surfaces 102 and 104 . Phase data from the two interferometer modules 50 and 52 can be combined to produce measurements having a greater dynamic range for accommodating test surfaces having roughness or other surface discontinuities that would otherwise yield ambiguous results.
[0047] Both interferometer modules 50 and 52 simultaneously measure the same points on either of the test surfaces 102 and 104 . Accordingly, phase information is directly combinable for producing measures at an effective wavelength λ e that is longer than the wavelengths λ 1 and λ 2 of the two interferometer modules 50 and 52 . The longer effective wavelength λ e allows phase information from the two interferometer modules 50 and 52 to be unambiguously resolved over a greater range of surface variation.
[0048] Although the illustrated probe 12 splits the combined test beam 86 into two sub-test beams 92 and 94 , the probe could be arranged to include other directional optics for splitting the combined test beam into three or more sub-test beams for similarly measuring three or more surfaces of a test piece, such as the cylindrical surface 102 , the truncated conical surface 104 , and a plane surface 103 of the test piece 14 . Instead of mounting the two interferometer modules 50 and 52 on the multi-axis stage assembly 16 , the interferometer modules 50 and 52 could be mounted independently of the stage assembly 16 and connected to the compound probe 12 by a flexible optical connection, such as a single mode optical fiber.
[0049] Our new method is preferably practiced by producing two beams (e.g., beams 56 ) of substantially coherent light having different fundamental wavelengths. The two fundamental wavelengths are preferably in the near-infrared range, where suitable laser sources are readily available for the field of telecommunications. Shorter wavelengths are subject to more speckle, and longer wavelengths generally require more expensive laser sources.
[0050] Both of the different wavelength beams 56 are divided into test beams 72 and 76 and reference beams 68 . The two test beams 72 and 76 are combined and later divided into first and second sub-test beams 92 and 94 , each including both fundamental wavelengths. A common focusing optic 88 focuses the first and second sub-test beams 92 and 94 to different points of focus 96 and 98 for separately measuring two different surfaces 102 and 104 of the test piece 14 .
[0051] As shown in FIG. 3, the point of focus 96 of the first sub-test beam 92 is positioned on the surface 102 of the test piece 14 while the point of focus 98 of the second sub-test beam 94 is positioned off of both test surfaces 102 and 104 . Precise positioning of the focus 96 on the test surface 102 can be achieved by monitoring modulation (contrast) or intensity as a function of position within either of the two interferometer modules 50 or 52 and choosing the position of greatest modulation or highest intensity. The focusing and imaging optics 88 and 126 cause both modulation and intensity to rapidly decrease for either point of focus 96 or 98 that departs from one of the test surfaces 102 or 104 .
[0052] The point of focus 96 of the first sub-test beam 92 is moved across the test surface 102 , while a data acquisition system, which includes the detectors 136 , 138 , 140 , and 142 , acquires point-by-point height information about the test surface 102 . Preferably, the data acquisition is timed with the rotation of the test piece 14 while the point of focus 96 is translated along a desired rotational profile of the test surface 102 . Typical speeds for measuring a 3.5 millimeter (mm) diameter internal surface are 600 revolutions per minute of rotation with 4 to 50 microns of translation per revolution. Data points are typically collected in an array of approximately 200-1000×1024, where the rows correspond to the increments of translation and the columns correspond to increments of rotation. Of course, more or less points can be acquired at these or other speeds.
[0053] As shown in FIG. 4, the other test surface 104 is measured by positioning the point of focus 98 of the second sub-test beam 94 on the test surface 104 while the point of focus 96 of the first sub-test beam 92 is positioned off of both test surfaces 102 and 104 . Similar monitoring techniques can be used to locate the point of focus 98 on the test surface 104 , and a similar combination of relative motions (e.g., rotation and translation) can be used to scan the point of focus 98 across the test surface 104 for acquiring a corresponding array of data.
[0054] At each of the two measuring positions, light retroreflected from one of the test surfaces 102 or 104 is refocused together with the reference beams 68 onto the detectors 136 , 138 , 140 , and 142 . Interference signals (i.e., phase differences) between the reference beams 68 and the first and second sub-test beams 92 and 94 are separately detected according to which of the sub-test beams 92 or 94 is positioned in focus on one of the test surfaces 102 or 104 . Optical path lengths of the reference beams 68 are preferably adjustable to provide nominally equal optical path lengths between the test and reference arms to eliminate phase variations caused by changes in temperature or laser wavelength fluctuations. The optical path lengths of the test and reference arms can also be nominally equated by making similar adjustments to the test arm.
[0055] The refocusing preferably includes limiting an aperture dimension of the refocused light to exclude from detection light from the sub-test beam 92 or 94 that is not focused onto one of the test surfaces 102 or 104 . The detectors 136 , 138 , 140 , and 142 , which can themselves be limited in aperture dimension, are preferably located at points of focus conjugate to the points of focus 96 and 98 of the two sub-test beams 92 and 94 .
[0056] The detectors 136 , 138 , 140 , and 142 are preferably arranged in two groups, each for measuring interference characteristics of one of the two fundamental wavelengths. The detectors within each group are separated in phase for simultaneously detecting phase-shifted interference signals between both of the pairs of test and reference beams having different fundamental wavelengths. Preferably, four detectors 136 , 138 , 140 , and 142 are phase shifted within each group through increments of 90 degrees. As few as three or more than four can be used to provide lesser or greater accuracy for discriminating phase information.
[0057] The phase information from each of the two groups of detectors 136 , 138 , 140 , and 142 provides precise information about variations in the test surfaces 102 or 104 over limited ranges corresponding to one-half the fundamental wavelengths λ 1 and λ 2 . However, the simultaneous phase information from the two groups of detectors 136 , 138 , 140 , and 142 can be combined to provide additional phase information that resolves phase ambiguities up to one-half of a longer effective wavelength λ e .
[0058] In addition to acquiring information about phase variations from one or the other of the two sub-test beams 92 or 94 , information is also acquired about the relative motions between the points of focus 96 and 98 and the test piece 14 . The additional information, which is collected simultaneously with the information from the sub-test beams 92 or 94 , includes deviations from a desired path of relative motion. The deviations of relative motion combined with the phase variations of the sub-test beams 92 or 94 provide accurate measures of test surface variations from the desired path of relative motion.
[0059] Conventional data analysis can be applied to these measures by the microprocessor 28 to extract measures of both form and geometry, including roughness, runout, concentricity, and tilt. Errors relating to the mounting and rotating of the test piece 14 , such as decenter and tilt, can be removed by conventional analysis techniques. Relational measurements can also be made between the two surfaces 102 and 104 , such as runout, co-axiality, and perpendicularity. A workstation 44 , an output 46 such as a printer or CRT, and a storage device 48 such as a hard disk or optical disk are connected to the microprocessor 28 to provide a conventional interface.
[0060] In addition to removing stage motion errors from probe profile measurements, the displacement-measuring interferometer 30 can also be used to resolve modulo 2 π phase ambiguities at the effective wavelength λ e of the combined measurements of the two interferometer modules 50 and 52 to produce absolute measurements of the test piece 14 . The displacement-measuring interferometer 30 can be calibrated to a master test piece of known dimensions, and the further relative motion required to move a point of focus 96 or 98 from a surface of the master having a known dimension (e.g., diameter) to a position on one of the test surfaces 102 or 104 can be measured. Combining the known dimension of the master with the further relative motion of the probe 12 to a measuring position provides an absolute measure of the test piece 14 within sufficient accuracy to resolve the modulo 2 π phase ambiguities at the effective wavelength λ e of the combined measurements of the two interferometer modules 50 and 52 .
[0061] As explained earlier, the probe 14 is moved to precise measuring positions by exploiting the confocal nature of the interferometric measurements made through the probe 14 . Both the modulation (contrast) of the interference signal and the intensity of light returning from the probe 14 to the detectors 136 , 138 , 140 , and 142 rapidly decrease as either point of focus 96 or 98 departs from one of the test surfaces 102 or 104 . The multi-axis stage assembly 16 can be adjusted to position the probe 14 to the measuring positions at which the highest modulation or intensity is detected, and the displacement-measuring interferometer 30 tracks the absolute location of these measuring positions from which the more precise interferometric measurements are made.
[0062] Precise absolute measurements of the test surfaces 102 and 104 can be made in stages. The information acquired from the calibrated displacement-measuring interferometer 30 resolves the modulo 2 π phase ambiguities at the effective wavelength λ e of the combined measurements of the two interferometer modules 50 and 52 , and the information acquired from the combined measurements of the two interferometer modules 50 and 52 at the effective wavelength λ e resolves the modulo 2 π phase ambiguities at either or both of the fundamental wavelengths λ 1 or λ 2 of the two interferometer modules 50 or 52 . Within the dimensions of the fundamental wavelengths λ 1 or λ 2 , conventional phase-shifting techniques, such as those based on the simultaneous detection of phase-shifted measurements by the multiple detectors 136 , 138 , 140 , and 142 , can be used to accurately identify the phase of the interference signals for even further extending the precision of the absolute measurements.
[0063] Although the two interference modules 50 and 52 are shown mounted on the multi-axis stage assembly 16 , the two modules 50 and 52 could also be mounted independent of the multi-axis stage assembly 16 and be connected to the probe 12 through a more flexible optical connection. For example, the two modules 50 and 52 could be connected to the probe 12 through fiber optics.
[0064] Two separate enclosures (neither shown) are used for environmental regulation. The control electronics are housed within one of the enclosures, and the optical and electromechanical components from the probe 12 to the rotary chuck 18 are housed in the other enclosure. The environmental control system (not shown) can include a solid-state thermoelectric cooler and heater, a blower assembly, and control and monitoring electronics positioned throughout the enclosures. Temperatures within 0.25 degrees Celsius are preferably maintained within the optical and electromechanical component enclosure.
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A scanning interferometer employs dual interferometer modules at different wavelengths to expand a dynamic range of measurement, a compound probe for measuring multiple surfaces, and a confocal optical system for distinguishing between the surfaces measured by the compound probe. Within the compound probe, miniature optics divide a test beam into two sub-test beams that are focused normal to different test surfaces. Both sub-test beams contain the different wavelengths. A separate interferometer monitors movements of the compound probe for producing absolute measures of the test surfaces.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional patent application No. 60/720,874 filed Sep. 27, 2005.
BACKGROUND
[0002] Over the past few years, there has been dramatic growth in the adoption of the mobile cellular telephone to the extent that it can largely be considered ubiquitous. This has led to a dichotomy in the world of enterprise voice call routing—for many years the voice world was neatly divided into “home” and “work” numbers. With mobile phones, the lines between a personal and an office extension are blurred—users want the flexibility of the mobile phone but the rich feature set of the modern desk phone. There is a need to reconcile this situation by allowing users to select what functionality they wish to receive when away from the desk.
[0003] There have been various schemes to provide enterprise telephony on mobile handsets. These schemes can be broken down into those that are a mobile handset as an extension of an office line and those that are a mobile handset as a replacement of an office line. The goal of the mobile handset as an extension of an office line model is to “extend” the office extension to the phone. An example is the Avaya “Extension to Cellular” system. This system binds together a mobile phone number to an office extension and when the PBX receives an inbound call to the office extension it also rings the mobile phone number bound to it by the enterprise communications server (ECS). Whichever phone picks up first is considered to “own” the call. In this way, users can give out just their office phone number, but can receive calls placed to that number on their cellular phones.
[0004] In order to provide additional functionality (such as being able to place outbound calls using the office extension but from the mobile phone), products such as Feature Name Extensions (FNE) exist. These expose internal PBX functionality through externally dialable phone numbers. For example, if a remote user wants to place an outgoing call from their office extension, they would first dial into the FNE number from their mobile phone. The PBX would recognize the user by cross referencing the mobile phone number through caller id, and request that the user enter a PIN. Once this has been done, the PBX allows the user to dial a number and completes the call on the user's behalf.
[0005] The mobile handset as a replacement of office line model focuses on providing an implementation of software on a mobile handset such that it can communicate directly with the enterprise PBX and effectively “become” an office phone. Examples of this are the Avaya IP softphone (which runs on PCs and Windows Mobile pocket pcs) and the Research In Motion 77xx series of BlackBerry® devices. While this model may provide robust and flexible functionality, the issue becomes one of transport of data. Because the device needs to be able to communicate directly with the PBX, it requires a secure channel over which to communicate—typically over a virtual private network (VPN). As bulk voice data is transported over the same channel, this requires a broadband connection for mobility—something that cannot be supported on generic wireless networks. For example, the RIM 77xx Blackberry® device requires a Wifi connection in order to provide enterprise voice functionality (over the session initiation protocol (SIP)). This bandwidth requirement makes the pure-replacement model one of limited use.
SUMMARY
[0006] In various embodiments, the present invention is directed to a method of facilitating telecommunication functionality on a mobile device. The method includes receiving a request for a telecommunications transaction from the mobile device and retrieving a callback identifier for a user of the mobile device. The method also includes executing the telecommunications transaction, wherein executing the transaction includes establishing a communications session that includes a callback telephony endpoint represented by the callback identifier and at least one target telephony endpoint, wherein a portion of the communications session that includes the callback telephony endpoint is established at least in part by making an outbound call from a telephony switch.
[0007] In various embodiments, the present invention is directed to a method of managing call functionality on a mobile device. The method includes sending a request for an application state from the mobile device to a server and transmitting a user profile from the server to the mobile device in response to the request for an application state. The method also includes combining contact information stored on the mobile device with the user profile to create a telecommunications transaction request, transmitting the telecommunications transaction request from the mobile device to the server, and placing, via a telephony switch, a call to execute the telecommunications transaction requested.
[0008] In various embodiments, the present invention is directed to a method of facilitating a telecommunications transaction using a telephone system. The method includes initiating, via a mobile device, a request for the telecommunications transaction, routing the request to a server, and identifying a user based on the request. The method also includes adding user profile information of the user to the request and transmitting the request and the user profile information to a control system of the telephone system to facilitate the requested telecommunications transaction.
[0009] In various embodiments, the present invention is directed to a method of generating a profile for a user of a mobile device, the profile containing information used by a telecommunications system to facilitate telecommunications functionality to the mobile device. The method includes retrieving an office telephone number of the user, identifying a private branch exchange (PBX) identifier associated with the user, and setting a default callback number to the office telephone number. The method also includes identifying a voice mail telephone number associated with the user and saving the PBX identifier, the default callback number, and the voice mail telephone number to the profile.
[0010] In various embodiments, the present invention is directed to a telecommunications system. The system includes a private branch exchange (PBX) device in communication with at least one telephone and a server in communication with the PBX device and a mobile device. The server is configured to receive a request for a telecommunications transaction from the mobile device and to retrieve a callback identifier for a user of the mobile device. The server is also configured to execute the telecommunications transaction, wherein executing the transaction comprises establishing a communications session that includes a callback telephony endpoint represented by the callback identifier and at least one target telephony endpoint, wherein a portion of the communications session that includes the callback telephony endpoint is established at least in part by making an outbound call from a telephony switch.
[0011] In various embodiments, the present invention is directed to an apparatus. The apparatus includes means for receiving a request for a telecommunications transaction from a mobile device and means for retrieving a callback identifier for a user of the mobile device. The apparatus also includes means for executing the telecommunications transaction, wherein the means for executing the transaction comprises means for establishing a communications session that includes a callback telephony endpoint represented by the callback identifier and at least one target telephony endpoint, wherein a portion of the communications session that includes the callback telephony endpoint is established at least in part by making an outbound call from a telephony switch.
[0012] In various embodiments, the present invention may also integrate directly into other components designed to store and expose the presence or location of users to the enterprise. Examples of such systems may be instant messaging systems, location based detection systems or GPS units located on other handhelds. Embodiments of the present invention may also interpret other pieces of information in order to determine presence, such as activity on various components such as desktop workstations and handheld devices. It may also check the status of work phones to determine whether or not users are currently actively engaged on a phone call. This presence information may be used to determine the availability of one or more target recipients of a call initiated through the system. If a user is not available for any reason, this information can be used to inform the call initiator, or perform another intelligent action such as alerting the intended recipient or waiting for a time when both participants are available and then initiate an enterprise call between the participants.
[0013] In various embodiments, the present invention is directed to a computer readable medium having stored thereon instructions which, when executed by a processor, cause the processor to:
[0014] receive a request for a telecommunications transaction from a mobile device;
[0015] retrieve a callback identifier for a user of the mobile device; and
[0016] execute the telecommunications transaction, wherein executing the transaction comprises:
[0017] establishing a communications session that includes a callback telephony endpoint represented by the callback identifier and at least one target telephony endpoint, wherein a portion of the communications session that includes the callback telephony endpoint is established at least in part by making an outbound call from a telephony switch.
[0018] In various embodiments, the present invention may check the presence of one or more recipients of a call in order to programmatically determine the availability of those recipients.
[0019] In various embodiments, the present invention may track the status and results of a call for storage in a database system designed to track information about calls such as call time, call duration and caller generated comments regarding that call.
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 illustrates an embodiment of a mobile computing system;
[0021] FIG. 2 illustrates an embodiment of a mobile computing process workflow;
[0022] FIG. 3 illustrates an embodiment of a server workflow;
[0023] FIG. 4 illustrates an embodiment of a mobile device workflow; and
[0024] FIG. 5 illustrates an embodiment of a process for creating a user profile.
DESCRIPTION
[0025] As used herein, the term “mobile device” includes any type of mobile device such as, for example, personal digital assistants (PDAs), wireless laptops, mobile phones, wearable computers, etc. Such devices may employ any type of mobile computing operating system such as, for example, the Palm OS® operating system, the Windows Mobile® operating system, the Blackberry® operating system, Linux-based operating systems, the Symbian® operating system, etc.
[0026] Various embodiments of the systems and methods described herein provide call-control functionality (e.g., multiple appearances, call control, hold setting and speed-dialing) available on desk phones while alleviating security and bandwidth concerns. Various embodiments of the present invention utilize an approach where enterprise call-control is separated from bulk voice transport for the purpose of providing rich enterprise telephony over existing voice channels. By separating the two systems from each other, a much lower bandwidth secure connection can be used for sending call control instructions, while the standard voice bearer networks are used for bulk voice traffic. Various embodiments of the present invention use a call-back voice number which is used as a proxy for voice application interaction.
[0027] An example of a call-back voice number follows. Amy has office extension 555-1234. She is currently out of the office but has her mobile phone 666-2345. She wishes to place a call to 444-3456. Using a client running on her BlackBerry device, she issues a request for the call with her cell phone indicated as the device to be called back (in some cases Amy's BlackBerry may be voice enabled and may be used as the device to be called back). On the server side, the request is cross referenced with enterprise LDAP to determine Amy's office extension and her cell phone number. Her office PBX is then instructed to place a call on Amy's behalf initiated using her extension (555-1234) and terminated at her cell phone (666-2345) (in other embodiments the call may be initiated using another number, e.g., from a number pool, or the number may not even be associated with a physical deskset). Once this call is connected, the target number (444-3456) is added, completing the call (e.g., the target number is also connected by the PBX via conventional call routing). From the perspective of the recipient, Amy is calling from her office line, even though she is actually using her mobile phone's voice connection. While the example describes the first leg of the voice connection being between Amy's cell phone and the PBX, and the second leg being between the PBX and the target number, the order in which the call is set up may be reversed or substantially simultaneous.
[0028] FIG. 1 illustrates an embodiment of a mobile computing system 10 . In the system 10 , a mobile telephone 12 and a device 14 (either referred to herein as “handheld mobile devices” or “mobile devices”) are in communication with a network 16 via a wireless network 18 . The telephone 12 and the device 14 are examples of devices that may be in communication with the wireless network 18 and it can be understood that any type of wireless device may be in communication with the wireless network 18 . The wireless network 18 may be any type of network, such as a cellular network, wireless telephone network, or a radio communications network. The network 16 may be any type of network such as, for example, a local area network (LAN) or the Internet. A computer 20 is in communication with the network 16 . The computer 20 may be any type of computer such as, for example, a personal computer.
[0029] In various embodiments, one or more of the telephone 12 and the mobile device 14 may include a software application client. The software client may utilize a secure connection to a server 22 as a communication and call control channel. The client may also provide a general user interface (UI) that users may interact with in order to provide secure transactions. On a mobile device such as a BlackBerry device the client may be a thick client written in, for example, Java J2ME. However, the client may be implemented in other languages or as a web-based console.
[0030] In various embodiments the software client may utilize a secure connection to the server 22 over which to issue (initiate) and receive transactions and data (e.g., a client may query and receive the voicemail status of the user). The client also may provide a UI for the end user to interact with the system 10 , view information and issue transactions. The client may also maintain a client side profile of user preferences and settings that can be used to customize the way that transactions are issued. Also, the client may provide an always-running mechanism or background application to which the server 22 can send real time alerts and information.
[0031] The network 16 is in communication with the server 22 , which manages mobile enterprise applications. In various embodiments the server 22 may, for thick client devices, expose a set of functionality through a network protocol (e.g., XML or SIP) that allows client applications on the telephone 12 and/or the mobile device 14 to issue telephony requests and queries. The server 22 also may enhance received transactions from devices 12 , 14 with information from local enterprise application data stores such as databases and LDAP directories (not shown). The server 22 may also expose a thin-client web-page based application that can be provided to users of devices 12 , 14 which may not be capable of running a native client application. The server 22 may communicate with a private branch exchange (PBX) system 28 through an appropriate API (the exact API and infrastructure may differ depending on the particular PBX vendor) in order to perform telephony actions. Embodiments of the present invention are also applicable to other telephone switches or telephony systems for routing voice calls, which may include VOIP systems.
[0032] A security device such as a firewall 24 may be interposed between the network 16 and the server 22 . The server 22 is in communication with enterprise applications 26 (running on other computer systems and/or on the server 22 ) and the PBX 28 . Telephones 30 are in communication with the PBX 28 . In various embodiments, the PBX 28 does not run any custom software to allow the functionality of the present invention, but it is an active participant. In various embodiments the PBX 28 allows the system 10 to programmatically control a given extension in order to place calls, place calls on hold, etc. Also, the PBX 28 allows the system 10 to receive events regarding a given extension (such as when it goes on/off hook, when it receives voicemail, etc).
[0033] In various embodiments the system 10 extends backend functionality to the devices 12 , 14 using telephony as a bulk data transport channel. The enterprise applications 26 and data sources (not shown) may provide data to augment transactions that are issued by the user from the mobile devices 12 , 14 . For example, the user may only specify a desire to call a given user—an LDAP directory may be used to look up the specific phone numbers of that user. Also, the user may specify that they want a conference call with all participants of a particular meeting. The system may check the calendar entry in, for example, Microsoft Exchange, look up the users' phone numbers, then create a conference call with those numbers as participants. The enterprise applications 26 and data sources may provide data to the user over a phone call. For example, a query to a CRM system may be provided on the mobile devices 12 , 14 . The system 10 queries the CRM system to retrieve the relevant information, then calls the user back to provide that data.
[0034] FIG. 2 illustrates an embodiment of a mobile computing process workflow. At step 40 , a user of a mobile device initiates a request to perform an action on the mobile device. The action may be a PBX telephony function that the user is capable of performing on a telephone connected to the PBX. In various embodiments, a request may only be initiated by a mobile device that is authorized to make such a request.
[0035] At step 42 , the requested transaction is routed to a server that manages mobile enterprise applications. The transaction may be routed, for example, over a secure channel. At step 44 , the transaction is received by the server (e.g., transaction broker software on the server) and at step 46 initiating user information is extracted and authenticated from the transaction data sent with the request. At step 48 , it is determined if the user profile of the user making the requested transaction is in memory (e.g., in a profile cache of the server). If the profile is not stored in memory, at step 50 a profile is created or loaded from a database (i.e., the user is provisioned).
[0036] At step 52 , the transaction is augmented with any missing information that may be required to complete the transaction based on profile information of all participants in the transaction. In various embodiments, such information may be, for example, telephone numbers, email addresses, calendar entries, etc. and may be obtained from internal or external enterprise applications such as, for example, a lightweight directory access protocol (LDAP) directory 54 , a preference database 56 (e.g., containing default information and user preferances), a PBX configuration database 58 , a personal information manager (PIM) server 60 , a CRM system, sales databases, etc. Also at this stage, the system may perform queries against any presence systems or indicators of presence that may be available to it. Examples of presence indicators may include, but are not limited to, instant messaging presence repositories, free-busy calendar information, activity indicators from desktop and handheld devices as well as the status of the user's enterprise telephone extension. For example, a user who is active on instant messaging and is not on the phone may be deemed to be available whereas a user who is active on instant messaging but is on a call may be deemed to be unavailable. This presence information is combined with the call information to determine when the best time to initiate the call would be. If the target user is unavailable, such status may be communicated back to the initiating user.
[0037] At step 62 , the transaction is issued to the telephony system that is responsible for controlling the PBX voice system and at step 64 an acknowledgement is sent to the initiating user (and any other participants) if such an acknowledgement is requested in the initial transaction (it could also be the case that acknowledgments are required by default).
[0038] FIG. 3 illustrates an embodiment of a server workflow that may be performed by a server that manages mobile enterprise applications. At step 70 the server receives a transaction request from a mobile device and at step 72 a user profile is loaded. At step 74 a call is placed to a callback number (i.e., a communication session is established that includes a callback telephony endpoint represented by the callback number and at least one target telephony endpoint) that is specified in the user profile of the initiating user (it could also be the case that the callback number is specified by the initiating user, e.g., overriding user profile information). At step 76 , it is determined whether the transaction is a voicemail check, a standard call, or a conference bridge. It can be understood that the transaction may be any other type of transaction and the three transactions illustrated in FIG. 3 are exemplary only.
[0039] If the transaction is a voicemail check transaction, at step 78 the appropriate voicemail number (i.e., target telephony endpoint) for the user's office extension is retrieved from the user profile (it could also be the case that this information was already cached at step 72 ) and at step 80 the user is connected with a voicemail system. An acknowledgement of the transaction is returned to the user at step 81 .
[0040] If the transaction is a standard call as determined at step 76 , the target user's (i.e., the called user's) number (i.e., a target telephony endpoint that is indentified by, for example, a routable phone number, an IP address, etc.) is obtained from, for example, an LDAP directory at step 82 (it could also be the case that the target user's number is specified by the initiating user) and at step 84 the call is connected to that number. An acknowledgement of the transaction is returned to the requesting user at step 81 .
[0041] If the transaction is a conference transaction as determined at step 76 , a conference bridge is created within the telephony switch if one does not already exist already, and a new line is added to the conference bridge at step 86 . At step 88 , the number (i.e., target telephony endpoint) that is to be conferenced is retrieved from, for example, an LDAP directory and at step 90 the call is connected to the number and the target user is conferenced into the bridge. At step 92 it is determined if there are more target users that need to be conferenced in. If so, the process returns to step 86 . If there are no further users to be conferenced in, an acknowledgement of the transaction is returned to the requesting user at step 81 . Embodiments of the present invention apply to conference calls as well as conference bridges.
[0042] FIG. 4 illustrates an embodiment of a mobile device workflow. At step 100 , an application for managing PBX functionality on a mobile device launches. The application may be launched by a user of the mobile device or may be started automatically upon, for example, startup of the mobile device. At step 102 , if the initiated application is stateless (i.e., does not possess the call back phone number, voicemail status, PBX desk handset status, etc.), a request is sent to a server that manages mobile enterprise applications for such state information. At step 104 , the server loads user profile information from, for example, an LDAP directory, a PBX system, etc.
[0043] At step 106 , the profile and state information is sent to the mobile device via, for example, a secure communications channel. At step 108 , the profile information is displayed to the user of the mobile device and at step 110 local contact information from, for example, a PIM in the mobile device is loaded into the application. At step 112 , the local contact information is combined with the profile information and displayed to the user on the mobile device until the user selects a transaction.
[0044] At step 114 , a selected transaction is combined with the local profile information and at step 116 the transaction is transmitted from the mobile device to the server via, for example, a secure channel. At step 118 , the server places the requested call as identified in the transaction using a PBX system.
[0045] FIG. 5 illustrates an embodiment of a process for creating a user profile by a server that manages mobile enterprise applications. At step 120 , the user profile generation process is initiated. Such initiation may be done, for example, on startup of the system or when provisioning a new user. At step 122 , the PBX extension of the user for which the profile is being generated is retrieved from, for example, an LDAP directory 124 . At step 126 , the user's PBX extension is cross referenced with a PBX mapping table to determine the PBX to which the user is assigned.
[0046] At step 128 , the process determines, from the user's PBX 129 , whether the PBX 129 is enabled for programmatic call control. If the PBX 129 is not so enabled, an error is reported at step 130 . At step 132 , the profile is augmented with additional phone numbers from, for example, the LDAP 124 . Such additional phone numbers may be phone numbers that the user desires to use other than the user's PBX extension and may include a mobile number, a home phone number, etc.).
[0047] At step 134 , the default callback number for the user may be set to the PBX office extension number for better security. At step 136 , the user's PBX extension is cross referenced with the user's external voicemail number so that if the PBX 129 employs different external voicemail numbers the profile will contain the correct number. At step 138 , the completed profile is saved for the user.
[0048] Various embodiments of the present invention provide mobile office extension control functionality. Such embodiments give a user access to office telephony functions by securely controlling the user's office extension directly through the enterprise PBX. On the mobile device, the user interacts with the system through a client. The user is able to perform actions such as:
Cause the PBX to place a call on the user's behalf using their office extension. The call is first placed to the registered callback number and then the call is completed to the destination. Select a series of users from a local address book and have the system create a conference call with those users as participants. The initiating user may select which numbers to reach the participants on, or may leave it to the system which will progressively attempt to reach the users on the numbers they have registered in, for example, an LDAP directory. Manipulate an existing call with additional actions such as:
Conferencing in a new participant Dropping a participant Putting the current call on hold Muting the current call
Check the availability and status of various people by instructing the backend to programmatically interrogate various presence repositories and sources of indirect presence information.
[0057] Various embodiments of the present invention allow a user to set a callback number. In such embodiments, the user is able to select from their registered office/home/mobile numbers in, for example, an LDAP directory or the user can instead set the number to another arbitrary number. If the user selects an LDAP-based number, this number is automatically resolved on the server side.
[0058] Various embodiments of the present invention allow a user to use a client to programmatically check the status of the user's voicemail (i.e., whether the user has new voicemail waiting on the user's office extension). Also, the user may see the number of voicemails received, when they were received and what numbers they are from. The user may also configure the system (e.g., a voicemail controlling agent) to automatically notify the user on, for example, a handheld device such as a BlackBerry device when a new voicemail is received by the enterprise system.
[0059] Various embodiments of the present invention allow a user to request to be connected to voicemail on a callback device. This is similar to a standard call, except the target number is automatically resolved by the system to be the externally dialable number for the user's voicemail system (each user may have a different external voicemail number depending on their home PBX).
[0060] Various embodiments of the present invention provided may be integrated into a paging/messaging system (e.g., SMS, email, instant messaging or alert). If a page/message is sent to a user, the sender may also choose to associate a phone number with the page/message. When the user receives the page/message, the user may automatically request to be connected to the sender on this number using the system. If there is no number associated with a page/message, the user may still choose to connect to the sender and the system will resolve the target numbers using, for example, an LDAP directory.
[0061] In various embodiments of the present invention, the server may attempt to intelligently decide the most appropriate phone numbers for target users. By maintaining presence and location information inside the client as well as the backend, the system allows users to select which phone number is best for them at any given time. It can also maintain a track of activity on a user's desktop or mobile device (e.g., a BlackBerry device) to determine whether a user is mobile or at their desk. Calls sent through the system may then use this presence information to select the appropriate number to dial.
[0062] The term “computer-readable medium” is defined herein as understood by those skilled in the art. It can be appreciated, for example, that method steps described herein may be performed, in certain embodiments, using instructions stored on a computer-readable medium or media that direct a computer system to perform the method steps. A computer-readable medium can include, for example and without limitation, memory devices such as diskettes, compact discs of both read-only and writeable varieties, digital versatile discs (DVD), optical disk drives, and hard disk drives. A computer-readable medium can also include memory storage that can be physical, virtual, permanent, temporary, semi-permanent and/or semi-temporary. A computer-readable medium can further include one or more data signals transmitted on one or more carrier waves.
[0063] As used herein, a “computer” or “computer system” may be, for example and without limitation, either alone or in combination, a personal computer (PC), server-based computer, main frame, microcomputer, minicomputer, laptop, personal data assistant (PDA), cellular phone, pager, processor, including wireless and/or wireline varieties thereof, and/or any other computerized device capable of configuration for processing data for either standalone application or over a networked medium or media. Computers and computer systems disclosed herein can include memory for storing certain software applications used in obtaining, processing, storing and/or communicating data. It can be appreciated that such memory can be internal or external, remote or local, with respect to its operatively associated computer or computer system. The memory can also include any means for storing software, including a hard disk, an optical disk, floppy disk, ROM (read only memory), RAM (random access memory), PROM (programmable ROM), EEPROM (extended erasable PROM), and other suitable computer-readable media.
[0064] It is to be understood that the figures and descriptions of embodiments of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements. Those of ordinary skill in the art will recognize, however, that these and other elements may be desirable for practice of various aspects of the present embodiments. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. It can be appreciated that, in some embodiments of the present methods and systems disclosed herein, a single component (e.g., a server, a telephony switch) can be replaced by multiple components, and multiple components replaced by a single component, to perform a given function or functions. Except where such substitution would not be operative to practice the present methods and systems, such substitution is within the scope of the present invention. Examples presented herein, including operational examples, are intended to illustrate potential implementations of the present method and system embodiments. It can be appreciated that such examples are intended primarily for purposes of illustration. No particular aspect or aspects of the example method, product, computer-readable media, and/or system embodiments described herein are intended to limit the scope of the present invention.
[0065] It should be appreciated that figures presented herein are intended for illustrative purposes and are not intended as construction drawings. Omitted details and modifications or alternative embodiments are within the purview of persons of ordinary skill in the art. Furthermore, whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of parts/elements/steps/functions may be made within the principle and scope of the invention without departing from the invention as described in the appended claims.
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A method of facilitating telecommunication functionality on a mobile device. The method includes receiving a request for a telecommunications transaction from the mobile device and retrieving a callback identifier for a user of the mobile device. The method also includes executing the telecommunications transaction, wherein executing the transaction includes establishing a communications session that includes a callback telephony endpoint represented by the callback identifier and at least one target telephony endpoint, wherein a portion of the communications session that includes the callback telephony endpoint is established at least in part by making an outbound call from a telephony switch.
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BACKGROUND OF THE INVENTION
This invention relates to a yarn feeder for a circular knitting machine equipped with stripers, particularly for application to the stripers associated with each set of machine cams and with a needle removal area of the needle cylinder and comprising a set of yarn guides selectively driven by a selector arrangement controlled by a control synchronised with the machine rotation and acting only once at the most on each of the selection arrangements on each rotation of the machine.
DESCRIPTION OF THE PRIOR ART
Circular knitting machines of the aforesaid type have the stripers thereof located on the periphery and in such a way as for there to be one device for each set of cams, each of them receiving four yarns, three of which are retained by the striper and the other of which is selectively fed to the needles.
Generally the changeover of the yarn fed by the striper to the needles is effected once at the most on each rotation of the machine in one same needle cylinder zone. This zone is known as the needle removal area, having a width of 20 to 30 needles, at the start of which certain needles are removed, whereas in the remaining portion the needle density is less than in the remainder of the cylinder.
In the yarn changeover process, the yarn to be inserted is offered up so that the needles receive it and start knitting even while the previous yarn is still being knitted, whereby for a short period of time two yarns are being knitted, namely the incoming yarn and the outgoing one.
Then, in view of the above, conventionally it is not possible positively to feed circular knitting machines equipped with stripers, since, the feed being constant and simultaneous for each and every one of the yarns, only one of every four yarns is knitted by the needles, the change is effected selectively depending on the characteristics of the fabric to be knitted and on the rotations on which there is no yarn changeover, there appears equally the needle removal zone in which, particularly in terry fabrics, the amount of yarn necessary for the needles varies considerably.
SUMMARY OF THE INVENTION
The object of the invention is to provide a yarn feeder capable of overcoming the above drawbacks and of feeding the yarns selectively.
The feeder of the invention is characterised by comprising:
(a) a fixed frame carrying two mutually parallel rotatable shafts, one being a primary shaft and being provided with a smooth cylindrical roller and a drive pulley and the other is a secondary one, carrying equidistant partly tapering and partly cylindrical driven rollers, the cylindrical portion of which engages said smooth cylindrical roller;
(b) operating spaces between the cylindrical roller and each of the driven rollers in which a moving yarn may pass;
(c) a plurality of inlet eyelets receiving the yarns from a creel and disposed on a sloping support attached to the frame on the outside of the circular knitting machine;
(d) a plurality of intermediate eyelets receiving the yarns from the rollers, disposed on a support attached to the frame;
(e) a plurality of arms pivoting around axes contained respectively on the median planes of the tapered portion of the driven rollers, mounted on the fixed frame and being provided at one end thereof with a yarn guide eyelet for the yarn fed by the inlet eyelets to the rollers, whereas at the other end they are provided with a ring receiving the yarn from the intermediate eyelets and with a terminal eyelet from whence the yarn moves to the needles, said eyelet being adapted, by the pivoting of the corresponding arm for assuming a position in which the yarn comprised between the said eyelet and the intermediate eyelet is trapped between the cylindrical roller and a cylindrical portion of the driven roller and consequently said yarn is fed by said rollers;
(f) a plurality of change of direction eyelets mounted on a horizontal curved support attached to the frame on the inside of the circular knitting machine, located in such a way that the sum of the distances from each of them to the ring and to the terminal eyelet of the corresponding arm, at the same angle of pivoting, is the same for all of them;
(g) springs urging the arms in the sense of keeping the yarn always under tension;
(h) adjusting means for the pivoting arm springs.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and characteristics of the invention will be disclosed in detail in the following description, to be read in connection with the attached drawings, in which:
FIG. 1 is an elevation view, partly in section, of the feeder of the invention, only two arms and the striper and one needle being schematically shown.
FIG. 2 is a plan view of the feeder, showing the four usual arms.
FIG. 3 is a side view of the feeder.
DETAILED DESCRIPTION
The yarn feeder of the invention for circular knitting machines comprises a fixed frame 1 in which there are mounted a rotatory primary shaft 2 driven by an external drive pulley 3, held in place by a nut 3a and being provided with a smooth cylindrical roller 4 covered with rubber, and a secondary shaft 5 parallel to the former and being provided with a plurality of driven rollers 6 having a cylindrical portion 6a engaging the smooth roller 4 and a tapered portion 7. The cylindrical portion 6a is preferably axially striate. The rollers 6 are preferably driven by a gear 50 attached to the shaft 2 and meshing with a further gear 51 attached in turn to the shaft 5, although the rollers 6 may be driven by friction from the roller 4. Also preferably the diameter of roller 4 is slightly larger (about 5 to 20%) than the diameter of the rollers 6. For example, the diameter of the smooth cylindrical roller 4 lies between 1.05 and 1.20, and preferably 1.10, times the diameter of the cylindrical portion of the driven rollers. In this case, when the rollers are driven by the gears 50, 51, a sliding action occurs between the respective surfaces thereof, producing the effects described hereinafter.
Said shafts 2 and 5 are mounted in respective ball bearings 8 and 9.
Mounted in the frame 1 there are supports 10, 11 and 12 to be described hereinbelow. The support 10 is inclined and is provided with a plurality of eyelets 13 through which pass the yarns 14 from the machine creel. Supports 11 and 12 are provided with further pluralities of eyelets 15 and change of direction eyelets 16 guiding the yarns 14 through the feeder as described below, support 11 being vertical and close to the plane tangent to both rollers 4,6 and support 12 being horizontal and curved.
Pivoting arms 17 are also supported on the frame 1 and are provided at one end thereof with an eyelet 18 for the yarn 14, whereas at the other end they are provided with a ring 19 and terminal eyelet 20 for the yarn towards the machine's needles. Each arm pivots about a corresponding axis (FIG. 3) contained generally in the median plane of the cylindrical portion 6a of the corresponding driven roller 6.
The pivoting arms 17 are provided with a traction spring 21 tending to draw the arms to an inoperative position, said springs having one end attached to tension adjusting device comprising a stud 22 with shaft 23 which may conveniently be set by a nut 23a and is provided with an offset pin 24 for holding the spring. The other end of the said springs 21 is attached to an intermediate elbow portion 25 of the corresponding arm 17. Thereby, for one same angle of pivoting of any of the arms, the amount of yarn stored between the ring 19, eyelets 16 of the support 12 and the eyelet 20 is always the same. There is a set of spring 21 and stud 22 for each arm, although only one set has been shown in FIG. 1 for clarity.
To engage the rollers 6 of the secondary shaft 5 with the cylindrical roller 4, there are springs 26 urging said shaft under a pressure regulatable by a screw 27.
The frame unit 1 is attached to the pertinent machine bedframe by binding screws 28.
In the example described, there are four arms 17 and sets of fixed eyelets 13, 15 and 16, since this is the usual number of yarns used in the said knitting machines, although the number may be different as desired.
Of the four yarns 14 used in the feeder as described, only one, namely the yarn previously selected by the striper 53, is being knitted, the remaining yarns being inoperative.
The yarn 14 selected at any one time is drawn in by the machine needles 54, pulling the corresponding arm 17 downwards against the opposition of the spring 21, without the arm 17 contacting the horizontal support 12 in any case, since the tension of the yarn 14 balances the tension of the spring 21, causing the yarn to move from the tapered portion 7 of the roller 6 on to the cylindrical portion to be trapped between the two rollers 6, 4. Since the cylinder 4 is driven to rotate, this causes the yarn to be pulled from the corresponding bobbin on the machine creel.
Under the above conditions, the selected yarn runs from the creel and enters the feeder through the eyelet 13 and from there to the inlet eyelet 18 of the arm 17, from which it is directed to the cylinders 4 and 6 as explained above where it runs through an operating space 29. Thereafter it passes through an eyelet 15 to be guided towards the ring 19 of the arm 17 and from there to the fixed eyelet 16, to terminate through the outlet eyelet 20 of the arm 17 and continue towards the needles 54. As may be seen from FIG. 1, when an arm 17 is activated, it pivots towards the support 12 of the eyelets 16, shortening the lengths formed successively between the ring 19 and the eyelets 16 and 20. When the arm 17 is in a rest position, the amount of yarn 14 fed in excess to the needles never exceeds the amount that may be stored between the ring 19, the eyelet 16 and the terminal eyelet 20 so that at any one time the feeder tensions the yarn with a constant tension irrespective of whether the yarn is being fed or not.
In other words, the striper 53 selects one of the yarns 14, shown as 14a in FIG. 1 and which is, therefore, the yarn which will be knit. The remaining yarns, such as 14b in FIG. 1 are not knit since they have not been selected. The needle 54 draws the yarn 14a, whereby the needle is fed at the expense of the loop of yarn comprised between the eyelet 20, the fixed eyelet 16 and the ring 19 of the same arm 17. As the yarn from this loop is consumed, the arm 17 pivots downwardly about its axis. Thereby, the part of the arm terminating with the eyelet 18 moves out of the position located at the height of the operating space 29 and rises up to the height of the cylindrical portion 6a of the corresponding roller 6. Consequently, the portion of yarn lying between the eyelet 18 of the arm 17 and the eyelet 15 of the support 11, passes to run between the cylindrical portion 6a of the roller 6 and the roller 4 and it is the movement of these rollers that drives the yarn along for the needle 54 to receive the necessary yarn without the needle 54 being subjected to undue stress.
The aforementioned sliding action prevents any sizing on the yarn from being deposited on the roller 4.
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A yarn feeder for a circular knitting machine having stripers receiving the yarns from the machine creel, each yarn following a set route through a plurality of fixed eyelets and moving eyelets located on a pivotable arm. The pivoting of the arm causes the length of yarn comprised between the eyelets to move between two rollers the rotation of which pulls the yarn along from the creel and delivers it to the needle which previously, while the arm was being caused to pivot, received the loop of yarn contained between two moving eyelets and a fixed eyelet.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vehicle controllers, and more particularly, to vehicle controllers provided with a continuously variable transmission and a motor-generator.
2. Description of the Related Art
Vehicles engines are generally provided with an alternator to generate electric power and a starting motor to start the engine. A motor-generator that combines the functions of both an alternator and a starting motor has recently been proposed for engines. The motor-generator basically includes a rotary shaft, a rotor core, and a stator core. The rotary shaft rotates integrally with a crankshaft, which is rotated by the engine. The rotor is provided on the rotary shaft. A wire is wound about the rotor. The stator core is fixed to an engine body. A stator wire is wound about the stator core to constitute an inductor. A voltage having a predetermined frequency is applied to the motor-generator's stator wire to produce a rotary magnetic field, the frequency of which is advanced with respect to the rotating speed of the rotary shaft. This causes the motor-generator to function as a motor. The rotational drive force of the motor applies a force to start the engine. When the vehicle is traveling, the motor adds accelerating force to the engine.
The motor-generator also functions as a generator when a rotary magnetic field having a frequency delayed with respect to the rotating speed of the rotary shaft is applied. In such a state, the motor-generator produces electric power. Proposals have been made to enhance the engine torque and to improve fuel consumption by motor-generators.
For example, Japanese Unexamined Utility Model 2-3101 describes a vehicle provided with a motor-generator and a continuously variable transmission. The publication proposes methods to improve the energy balance of the engine, upgrade fuel consumption, and enhance engine maneuverability that includes factors such as the acceleration and deceleration ability. In this publication, the motor-generator functions as a generator in correspondence with an engine brake. This decreases the engine speed by applying torque to the engine. However, the motor function of the motor-generator is not effectively used to compensate the engine speed.
The continuously variable transmission has a continuous shifting characteristic and is thus optimum for the purpose of improving maneuverability. However, the continuously variable transmission has a few characteristic problems such as torque fluctuation caused by the moment of inertia that is applied to an input shaft of the transmission. Thus, the combination of the continuously variable transmission and the motor-generator may result in deficiencies.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to improve the performance of a continuously variable transmission, provided in a vehicle together with a motor-generator, through the cooperation between the motor-generator and the variable transmission.
Another objective of the present invention is to provide a controller for a vehicle that compensates a torque level resulting from the moment of inertia in an engine, motor-generator, and a continuously variable transmission. The compensation enables the speed to be accurate during operation.
It is also an objective of the present invention to provide a controller for a vehicle that ensures stable assist controlling of the engine regardless of an electric power source being in a low voltage state.
A further objective of the present invention is to provide a controller for a vehicle that enables manual shift down to be performed smoothly.
Another objective of the present invention of the present invention is to provide a controller for a vehicle that enables a balanced shifting value with respect to a target vehicle speed during operation.
A final objective of the present invention is to provide a controller for a vehicle that enables the rotating speed of the continuously variable transmission and the engine to be maintained in a substantially constant state. This enables the operating state to be maintained in a satisfactory state.
To achieve the above objectives a control apparatus for a vehicle includes a power transmitting system between an engine and wheels. The transmitting system has a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode. The motor-generator serves as a generator in a regenerating operation mode and as a motor in an assisting operation mode.
In one aspect of the present invention, the control apparatus includes determining means for determining a shift of engine speed, computing means for computing a total moment of inertia of the engine, the CVT and the motor-generator, and correcting means for correcting the engine speed. The correcting means selects one of the operation modes of the motor-generator to actuate the motor-generator based on the selected operation mode.
In another aspect of the present invention, the motor-generator actuated in the regenerating operation mode charges power source to induce torque required for reducing the engine speed. A maximum chargeable voltage is determined based on a currently residual voltage in the power source. The speed of the vehicle is manually shifted. The control apparatus includes detecting means for detecting the manual shift operation for reducing a speed of the vehicle, computing means for computing the required torque based on the vehicle speed and an acceleration of the vehicle, comparing means for comparing the required torque and the maximum chargeable voltage, and control means for controlling the motor-generator. The control means actuates the motor-generator in the regenerating operation mode based on the required torque being smaller than the maximum chargeable voltage. The control means controls to reduce the rotational speed of the CVT based on an excessive level of the required torque when the required torque is greater than the maximum chargeable voltage.
In a further aspect of the present invention, the control apparatus includes recognizing means for recognizing a shift of the engine speed shift, and actuating means for actuating the motor-generator in one of the operation modes in accordance with the recognized shift of the engine speed.
In still another aspect of the present invention, the motor-generator is actuated in one of the regenerating operation mode to charge a power source and reduce the engine speed and the assisting operation mode to increase the engine speed. The control apparatus includes hydraulic control means for controlling the CVT, and detecting means for detecting a temperature of fluid in the hydraulic control means being smaller than a predetermined magnitude. The predetermined magnitude is a minimum level for ensuring a start-up pressure of the fluid. The apparatus further includes determining means for determining an increase of the engine speed, computing means for computing torque required to reduce the engine speed in association with a delay of the start-up pressure of the fluid, and actuating means for actuating the motor-generator in the regenerating mode to charge the power source with voltage based on the required torque.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a schematic drawing of a vehicle power transmission system according to an embodiment of the present invention;
FIG. 2 is an electric block diagram of the power transmission system;
FIG. 3 is a characteristic diagram showing the relationship between the engine speed and the torque of a motor-generator;
FIGS. 4(a) and 4(b) are a time chart of an output torque and a CVT input shaft rotating speed;
FIG. 5 is a characteristic diagram showing the relationship between the vehicle speed and an actual CVT input shaft rotating speed;
FIG. 6 is a time chart of a CVT shift flag and a CVT input shaft rotating speed in a constant speed state;
FIG. 7 is a time chart of the engine torque and a CVT input torque;
FIG. 8 is a time chart of a belt pressing hydraulic pressure;
FIG. 9 is a flowchart illustrating assist controlling and regeneration controlling of the motor-generator;
FIG. 10 is a flowchart illustrating assist controlling and regeneration controlling of the motor-generator;
FIG. 11 is a flowchart illustrating assist controlling and regeneration controlling of the motor-generator;
FIG. 12 is a flowchart showing a CVT shift restricting routine;
FIG. 13 is a flowchart of the regeneration controlling during manual shift down;
FIG. 14 is a flowchart of a routine for computing the maximum regeneration torque of the motor-generator;
FIG. 15 is a flowchart of a control routine executed when the CVT is in a constant speed state; and
FIG. 16 is a flowchart of a motor-generator control routine executed when the CVT oil temperature is low.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of vehicle controller according to an embodiment of the present invention will hereafter be described with reference to FIGS. 1 to 15.
FIG. 1 illustrates a vehicle transmission system. A casing 15a for a damper 15 connects a crankshaft 11a of an engine 11 to a rotor 13 of a motor-generator 12. The power of the engine 11 is transmitted to an input shaft 16 by way of the damper 15. The power transmitted to the input shaft 16 is conveyed to a forward/rearward shifting mechanism 17. The mechanism 17 is constituted from a double pinion type planet gear. When the mechanism 17 is engaged with an advancing clutch 18, the mechanism 17 rotates integrally with the engine 11 at a forward position. When the mechanism 17 is engaged with a retreating brake 19, the mechanism 17 is maintained at a rearward position. The clutch 18 and the brake 19 also serve as a starting mechanism. The power from the mechanism 17 is transmitted to an input shaft 20 of a continuously variable transmission (CVT) 21.
An output shaft 22 of the CVT 21 is connected to a gear type power transmission mechanism 23 constituted by a plurality of gearsets. The mechanism 23 is connected to a differential gear 25 which is provided on an axle 24 with wheels (not shown) mounted thereon. The motor-generator 12 is accommodated in a housing 27 together with the forward/rearward shifting mechanism 17, the CVT 21, the gear type power transmission mechanism 23, and the differential gear 25. The housing 27 is fixed integrally to the engine 11.
The motor-generator 12 is provided with the rotor 13 and a stator 14. The rotor 13 is constituted by a rotor core that rotates integrally with the crankshaft 11a. A rotor wire 31 is wound about the rotor core. The stator 14 is constituted by a stator core fixed to the housing 27. A stator wire 33 is wound about the stator core. An oil pump 26 is provided between the motor-generator 12 and the CVT 21. The oil pump 26 is connected to and driven by the input shaft 16.
A voltage having a predetermined frequency is applied to the stator wire 33 of the motor-generator 12 to produce a rotary magnetic field which frequency is advanced with respect to the rotating speed of the crankshaft 11a. This causes the motor-generator 21 to function as a motor. The rotational drive force of the motor-generator 12, produced from electric power, applies a force to start the engine 11. When the vehicle is traveling, the motor-generator 12 adds accelerating force to the engine 11.
Alternatively, when a voltage of a different frequency is applied to the stator wire 33, the motor-generator 12 produces a rotary magnetic field, the frequency of which is delayed with respect to the rotating speed of the rotary shaft. This causes the motor-generator 12 to function as a generator.
The CVT 21 is constituted by a primary pulley 37 provided on an input shaft 20, a secondary pulley 38 provided on the output shaft 22, and a belt 39. The effective pitch diameter of the pulleys 37, 38 are variable.
The primary pulley 37 includes a fixed plate 40, which is fixed to the input shaft 20, and a movable plate 41, which is slidably coupled to the input shaft 20. Both plates 40, 41 are conical and are arranged opposed to each other in a manner such that they define a V-groove 42. The effective pitch diameter of the primary pulley 37 becomes large as the movable plate 41 approaches the fixed plate 40 and becomes smaller as the movable plate 41 moves away from the fixed plate 40.
The secondary pulley 38 includes a fixed plate 43, which is fixed to the output shaft 22, and a movable plate 44, which is slidably coupled to the output shaft 22. Both plates 43, 44 are conical and are arranged opposed to each other in a manner that they define a V-groove 45. The effective pitch diameter of the secondary pulley 38 becomes large as the movable plate 44 approaches the fixed plate 43 and becomes smaller as the movable plate 44 moves away from the fixed plate 43.
Hydraulic cylinders 46, 47 are provided behind the movable plates 41, 44 of the pulleys 37, 38, respectively, to slide the movable plates 41, 44. Both hydraulic cylinders 46, 47 are connected to a shift control valve 58 (FIG. 2) which controls hydraulic pressure.
When hydraulic oil is supplied to the hydraulic cylinder 46 of the primary pulley 37, the movable plate 41 slides along the shaft 20 toward the fixed plate 41 and increases the effective pitch diameter of the primary pulley 37. The effective pitch diameter of the secondary pulley 38 simultaneously becomes smaller. Accordingly, the gear ratio of the CVT 21 is altered to the accelerating side. Contrarily, the effective pitch diameter of the primary pulley 37 becomes small and the effective pitch diameter of the secondary pulley 38 becomes large when hydraulic oil is discharged from the hydraulic cylinder 46. Accordingly, the gear ratio of the CVT 21 is altered to the decelerating side. Hydraulic oil is constantly supplied to the hydraulic cylinder 47 of the secondary pulley 38 to maintain the tension of the belt 39 adjusted at an appropriate level in accordance with the transmission torque.
The electric structure of the control system will now be described with reference to FIG. 2.
A rotating speed sensor 51, a throttle angle sensor 52, and a vehicle speed sensor 53 are connected to an electronic control unit (ECU) 50. The rotating speed sensor 51 detects the rotary speed Ne of the engine crankshaft 11a. The throttle angle sensor 52 detects the throttle angle THR of the engine 11. The vehicle speed sensor 53 detects the vehicle speed SPD. An input shaft rotating speed sensor 54, a shift range switch 55, and an oil temperature sensor 56 are also connected to the ECU 50. The input shaft rotating speed sensor 54 detects the rotating speed (actual rotating speed) N in . of the input shaft 20. The shift range switch 55 detects the gear position. The oil temperature sensor 56 serves as an oil detecting means that detects the temperature (oil temperature) T HO of the hydraulic oil in the CVT 21.
When the motor-generator 12 is started, a battery (electric power source) supplies electricity to the motor-generator 12 so that the motor-generator 12 functions as an electric motor. When the motor-generator 12 is not being started, a condenser having a large capacity is used as an electric power source to have the motor-generator function as an electric motor.
The ECU 50 controls the energized state of the stator wire 33 when the motor-generator 12 is started. More particularly, the ECU 50 applies a predetermined frequency voltage to the stator wire 33 when an ignition switch (not shown) sends an ON signal to the ECU 50. This causes the motor-generator 12 to function as an electric motor. Consequently, the input casing 15a of the damper 15 is rotated by the drive torque produced by the rotor 13. This rotates the engine crankshaft 11a and starts the engine 11. The ignition switch is maneuvered to an OFF position after the engine 11 is started. This results in the ECU 50 receiving an OFF signal. The ECU 50 then stops energizing the stator wire 33 and causes the motor-generator 12 to enter a generating mode (regeneration mode).
When the motor-generator 12 is not being started, the ECU 50 drives the motor-generator 12 as an electric motor based on detecting signals sent from various sensors and a control program instead of the ON signal sent from the ignition switch.
When the motor-generator 12 is operated in the regeneration mode, a predetermined frequency voltage is applied to the stator wire 33 to produce a rotary magnetic field, the frequency of which is delayed with respect to the rotating speed of the crankshaft 11a. This causes the motor-generator 12 to function as a generator. The consumed drive torque and generated electric power of the motor-generator 12 varies with respect to the engine rotating speed Ne in accordance with the value of a controlling electric current flowing through the stator wire 33. In other words, the greater the value of the controlling electric current is, the greater the generated electric power becomes. The drive torque (engine torque) consumed to obtain the generated electric power also becomes large.
The ECU 50 reads the signals sent from various sensors connected thereto and controls the motor-generator 12 based on the signals and various control programs stored in an incorporated ROM. This enables the motor-generator 12 to function as a motor by performing regeneration controlling or to function as a generator by performing assist controlling. The ROM also stores various maps that are used to process routines in various programs.
During performance of assist controlling and regeneration controlling, the electric power source of the motor-generator 12 is switched from the battery to the condenser (not shown). Accordingly, a voltage detector 57, which detects the capacitor voltage V of the condenser, is connected to the ECU 50.
The ECU 50 controls the shift control valve 58 to actuate the CVT 21. The gear ratio of the CVT 21 is controlled by feedback control. For example, a target rotating speed N ino is set based on the throttle angle THR and the vehicle speed SPD. The actual rotating speed N in is feedback controlled so that it is set as the target rotating speed N ino . The ECU 50 also controls a clutch control valve 60 during clutch controlling in an optimum manner.
The processing performed by the ECU 50 after the starting of the engine 11 will now be described with reference to FIGS. 8 to 15.
FIGS. 9 to 11 illustrate a flowchart of a routine that is executed by the ECU 50 to perform assist controlling and regeneration controlling of the motor-generator 12. Periodic interrupting is carried out every predetermined time period to execute the routine. When the ECU 50 enters the routine, the ECU 50 judges whether an assist flag MG1 is set at zero in step S10. Since the assist flag MG1 is initially set at zero, the ECU 50 proceeds to step S20. At step S20, the ECU 50 judges whether the regeneration flag MG2 is set at zero. Since the regeneration flag MG2 is initially set at zero, the ECU 50 proceeds to S30.
At step S30, the ECU 50 judges whether the difference between the throttle angle THR i and the throttle angle THR.sub.(i-1) in the previous cycle exceeds a predetermined reference value A (A>0). If the difference between the throttle angles exceeds the reference value A, this indicates an accelerating state. If the difference is below the reference value A, this indicates that accelerating is not taking place. When an accelerating state is confirmed, the ECU 50 proceeds to step S50. When it is determined that accelerating is not taking place, the ECU 50 proceeds to step S40. At step S40, the ECU 50 judges whether the difference between the throttle angle THR i and the throttle angle THR.sub.(i-1) in the previously cycle is lower than a predetermined reference value B (B<0). If the difference between the throttle angles is lower than the reference value B, this indicates a decelerating state. In this case, the ECU 50 proceeds to step S140. If the difference exceeds the reference value B, the ECU 50 determines that decelerating is not taking place. In this case, the ECU 50 terminates execution of the routine.
If the assist flag MG1 is determined to be set at one in step S10 or if an accelerating state is confirmed at step S30, the ECU 50 proceeds to step S50 and judges whether the difference between the target rotating speed N ino and the actual rotating speed N in exceeds a predetermined reference value N1 (N1>0). This is to judge whether the down shifting of the CVT 21 has been completed.
FIG. 4(a) illustrates a time chart of the target rotating speed N ino and the actual rotating speed N in . It is apparent from FIG. 4 that there is a delay in the actual rotating speed N in with respect to the target rotating speed N ino . Accordingly, the ECU 50 determines that the shifting has been completed in the case that the difference between the target rotating speed N ino and the actual rotating speed N in is smaller than the reference value N1. The target rotating speed N ino is computed from the throttle angle THR and the vehicle speed SPD. When the difference between the target rotating speed N ino and the actual rotating speed N in exceeds the reference value N1, the ECU 50 determines that shifting is being performed. In this case, the ECU 50 proceeds to step S60 and sets the assist flag MG1 to one.
At step S70, the difference ΔN e (altering speed) between the engine speed N e and the engine speed N e (i-1) of the previous cycle is computed. The difference ΔN e corresponds to a rotating speed altering rate. In the same step, the difference ΔN in (altering speed) between the actual rotating speed N in of the CVT 21 and the actual rotating speed N in (i-1) of the CVT 21 is also computed. The difference ΔN in corresponds to a rotating speed altering rate. The ECU 50 then proceeds to step S80 and reads the engine's moment of inertia I e , the motor-generator rotor's moment of inertia I x , and the CVT input shaft's moment of inertia I in , which are stored in the ROM (not shown). These values are either obtained through experiments or are theoretical values.
At step S90, the ECU 50 computes the inertia torque. In other words, the inertia torque T Ie of the engine 11 is obtained through a function f(I e , ΔN e ). The function f corresponds to the equation of f(I e , ΔN e )=I e ×K×ΔN e . K represents a constant related to the controlling cycle. In the same manner, the inertia torque T Ir of the motor-generator 12 and the inertia torque T Iin of the CVT 21 are respectively obtained from the functions f(I x , ΔN e ) and f(I in , ΔN in ). When the advancing clutch 18 is completely engaged, the engine crankshaft 11a and the input shaft 20 of the CVT 21 rotate integrally. Thus, the engine speed N e coincides with the actual rotating speed N in of the input shaft 20. In this case, the inertia torque T Iin of the CVT 21 is obtained from the function f(I in , ΔN e ). The ECU 50 then proceeds to step S100 and computes the total inertia torque T It . This computation is obtained from the equation of T It =T Ie +T Ir +T Iin .
At step S110, the controlling electric current value I M/G of the motor-generator 12 is obtained through a map stored in the ROM. As shown in FIG. 3, the map is three-dimensional and includes the engine speed N e , the inertia torque T It , and the controlling electric current value I n . These values are obtained through experiments. As shown in the map of FIG. 3, the controlling electric current value I M/G , which corresponds to the inertia torque T It and the engine speed N e , is selected from I 1 , I 2 , I 3 , etc. (I 1 >I 2 >I 3 >I n , n=4, 5, 6, . . . ). The ECU 50 then proceeds to step S120 and sends a controlling electric current value I M/G , computed in step S110, to the motor-generator (M/G) 12 and performs assist controlling of the motor-generator 12. In other words, the motor-generator 12 is driven as an electric motor by a power corresponding to the torque T it . The routine is terminated after execution of step S120.
When the difference between the target rotating speed N ino and the actual rotating speed N in of the input shaft 20 is lower than the reference value N1 in step S50, the ECU 50 determines that shifting has been completed and proceeds to step S130 to reset the assist flag MG1 to zero. The ECU 50 also stops performing assist controlling and terminates execution of the routine.
When the assist flag MG2 is set at one in step S20 or when decelerating is confirmed in step S40, the ECU 50 proceeds to step S140 and judges whether the difference between the target rotating speed N ino and the actual rotating speed N in is lower than a reference value N2(N2<0). In other words, the CVT 21 is up shifted when decelerating. Thus, the ECU 50 judges whether the shifting has been completed. FIG. 4(a) illustrates the time chart of the target rotating speed N ino and the actual rotating speed N in . It is apparent from FIG. 4 that there is a delay in the actual rotating speed N in with respect to the target rotating speed N ino . Accordingly, the ECU 50 determines that the shifting has been completed in the case that the difference between the target rotating speed N ino and the actual rotating speed N in exceeds the reference value N2. When the difference between the target rotating speed N ino and the actual rotating speed N in is lower than the reference value N2, the ECU 50 determines that the CVT 21 is still shifting and proceeds to step S150 to set the regeneration flag MG2 to one.
At step 160, the absolute value of the difference ΔN e (altering speed) between the engine speed N e and the engine speed N e (i-1) of the previous cycle is computed. The difference ΔN e corresponds to the rotating speed altering rate. The absolute value of the difference ΔN in (altering speed) between the actual rotating speed N in of the CVT 21 and the actual rotating speed N in (i-1) of the CVT 21 in the previous cycle is computed. Step S160 serves as a second detecting means. The ECU 50 then proceeds to step 170 and reads the engine's moment of inertia I e , the motor-generator rotor's moment of inertia I r , and the CVT input shaft's moment of inertia I in , which are stored in a ROM.
At step S180, the ECU 50 computes the inertia torque. The ECU 50 obtains the inertia torque T Ie of the engine 11 through the function f(I e , ΔN e ). The function f corresponds to the equation of f(I e , ΔN e )=I e ×K×ΔN e . K represents a constant related to the controlling cycle. In the same manner, the inertia torque T Ir of the motor-generator 12 and the inertia torque T Iin of the CVT 21 are respectively obtained from the function f(I r , ΔN e ) and the function f(I in , ΔN in ). When the advancing clutch 18 is completely engaged, the engine crankshaft 11a and the input shaft 20 of the CVT 21 rotate integrally. Thus, the engine speed N e coincides with the actual rotating speed N in of the input shaft 20. In this case, the inertia torque T Iin of the CVT 21 is obtained from the function f(I in , ΔN e ). The ECU 50 then proceeds to step S190 and computes the total inertia torque T It . This computation is obtained from the equation of T It =T Ie +T Ir +T Iin .
At step S200, the controlling electric current value I M/G of the motor-generator 12 is obtained through a map stored in the ROM. As shown in FIG. 3, the map is three-dimensional and consists of the engine speed N e , the inertia torque T It , and the controlling electric current value I n . These values are obtained through experiments. As shown in the map of FIG. 3, the controlling electric current value I M/G , which corresponds to the inertia torque T It and the engine speed N e is selected from I 101 , I 102 , I 103 , etc. (I 101 <I 102 <I 103 <I m , m=104, 105, 106, . . . ). The ECU 50 then proceeds to step S210 and sends a controlling electric current value I M/G , obtained in step S200, to the motor-generator 12 (stator wire 33) and performs regeneration controlling of the motor-generator 12. In other words, the motor-generator 12 serves as a generator and regenerates electric current and also charges the condenser (not shown). The regeneration controlling enables electric power to be obtained. However, drive torque is consumed to obtain the electric power. The routine is terminated after execution of step S210.
When the difference between the target rotating speed N ino and the actual rotating speed N in exceeds the reference value N2 in step S140, the ECU 50 determines that the shifting has been completed and proceeds to step S220 to reset the regeneration flag MG2 to zero. The ECU 50 also stops performing assist controlling and terminates execution of the routine.
At steps S70 to S120, the decrease in the level of the inertia torque, which is caused by an increase in rotating speed due to the engine's moment of inertia I e , the motor-generator rotor's moment of inertia I r , and the CVT input shaft's moment of inertia I in , is computed. The computed decrease in torque is replenished by the motor-generator 12. As a result, a torque decrease is prevented since the motor-generator 12 compensates (assists) the torque decrease caused by inertia. The area indicated by slanted lines between a line representing controlling of the motor-generator (M/G) and a line representing non-controlling of the motor-generator (M/G) in FIG. 4(b) illustrates an assist area, or the compensated torque decrease.
At steps S160 to S210, the input system inertia torque during a decrease in rotating speed due to the engine's moment of inertia I e , the motor-generator rotor's moment of inertia I r , and the CVT input shaft's moment of inertia I in is computed. The motor-generator 12 regenerates electric power that corresponds to the computed torque decrease. As a result, torque shocks that are produced during up shifting are reduced by regenerating the input shaft inertia torque with the motor-generator 12. The area indicated by slanted lines between the line representing controlling of the motor-generator (M/G) and the line representing non-controlling of the motor-generator (M/G) in FIG. 4(b) illustrates a regeneration area, or the compensated torque decrease.
Furthermore, at step S50, the ECU 50 determines that the acceleration of the CVT 21 has been completed when the difference between the target rotating speed N ino and the actual rotating speed N in of the CVT 21 is lower than the reference value N1. The torque assist of the motor-generator 12 is terminated at the point of time when the acceleration is stopped. This coincides the torque assist completion timing of the CVT 21 and the motor-generator 12. As a result, the fluctuation of the drive force is reduced.
In addition, at step S140, the ECU 50 determines that the deceleration of the CVT 21 has been completed when the difference between the target rotating speed N ino and the actual rotating speed Nin of the CVT 21 exceeds the reference value N1. The regeneration controlling of the motor-generator 12 is terminated at the point of time when the deceleration is stopped. This coincides the regeneration controlling completion timing of the CVT 21 and the motor-generator 12. As a result, the fluctuation of the drive force is reduced.
A routine employed to restrict the shifting of the CVT 21 will now be described with reference to FIG. 12. Periodic interrupting is carried out every predetermined time period to execute the routine. When the ECU 50 proceeds to this routine in step 300, the assist torque maximum value T M/G of the motor-generator 12 is obtained through a map stored in the ROM. The map is three-dimensional and consists of the engine speed N e , the capacitor voltage V, and the assist torque maximum value T M/G . These values are obtained through experiments. In other words, the controlling electric current value that may be supplied to the motor-generator 12 is obtained from the capacitor voltage V. Thus, the assist torque maximum value T M/G is obtained from the capacitor voltage V and the engine speed N e .
The reason for monitoring the capacitor voltage V, that is, the reason for obtaining the assist torque maximum value T M/G is as follows. When assist controlling of the motor-generator 12 is performed, its electric power source is a large-capacity condenser (not shown). When regeneration controlling of the motor-generator 12 is performed, its generated electric power charges the condenser. Accordingly, the capacitor voltage of the condenser is not maintained at a constant value due to the difference in the frequency in the execution of the assist controlling and the regeneration controlling. Thus, depending on the capacitor voltage, compensation of the assist area shown in FIG. 4(b) may become impossible. Thus, monitoring the capacitor voltage V and obtaining the assist torque maximum value T M/G is extremely effective.
At step S310, the ECU 50 reads the engine's moment of inertia I e , the motor-generator rotor's moment of inertia I r , and the CVT input shaft's moment of inertia I in which are stored in the ROM. At step S320, the ECU 50 computes the total value I t of these moment of inertias. The ECU 50 then proceeds to step S330 and computes the input shaft maximum rotating speed altering rate ΔN inmax , which corresponds to the maximum shifting speed of the input shaft 20 of the CVT 21. The altering rate ΔN inmax is obtained by dividing the assist torque maximum value T M/G with a multiplied value calculated from the formula of constant K1×moment of inertia total value It.
The ECU 50 then proceeds to step S340 and judges whether the maximum rotating speed altering rate ΔN inmax is smaller than the target rotating speed altering rate ΔN ino . The target rotating speed altering rate ΔN ino is a differential value of the target input shaft rotating speed N ino under each corresponding condition and is obtained through a different routine. When it is determined that the maximum rotating speed altering rate ΔN inmax is greater than the target rotating speed altering rate ΔN ino in step S340, the ECU 50 proceeds to step S350 and sets the target rotating speed altering rate ΔN ino as the target rotating speed altering rate ΔN ino for controlling the CVT 21. When it is determined that the maximum rotating speed altering rate ΔN inmax is smaller than the target rotating speed altering rate ΔN ino in step S340, the ECU 50 proceeds to step S370 and sets the maximum rotating speed altering rate ΔN inmax as the target rotating speed altering rate ΔN ino for controlling the CVT 21. At step 360, the ECU 50 controls the shift control valve 58 of the CVT 21 in accordance with the target rotating speed altering rate ΔN ino , which is set in either step S350 or step S370.
At step 340, when the maximum rotating speed altering rate ΔN inmax is smaller than the target rotating speed altering rate ΔN ino , the ECU 50 proceeds to step S370 and sets the maximum rotating speed altering rate ΔN inmax as the target rotating speed altering rate ΔN ino for controlling the CVT 21. This is carried out due to the reasons described below.
If the target rotating speed altering rate ΔN ino is greater than the maximum rotating speed altering rate ΔN inmax , setting the maximum rotating speed altering rate ΔN inmax as the target rotating speed altering rate ΔN ino allows reduction in the inclination (increasing rate) of the onset of N ino , shown in FIG. 4(a), and applies a guard. As a result, the inclination of the output torque during controlling of the motor-generator 12 that is shown in FIG. 4(b) is reduced. This leads to a reduction of the assist area. If the target rotating speed altering rate ΔN ino is greater than the maximum rotating speed altering rate ΔN inmax , and this high target rotating speed altering rate ΔN ino is to be used as the target value, the inclination (increasing rate) of the onset of N ino , shown in FIG. 4(a), would be increased. This results in an increase in the inclination of the output torque during controlling of the motor-generator 12. Thus, the assist area is increased and assist by the motor-generator 12 becomes impossible.
Accordingly, by controlling the shifting of the CVT 21 based on the maximum rotating speed altering rare ΔN inmax , assist controlling of the motor-generator 12 may be controlled regardless of the capacitor voltage V becoming low. This prevents the output torque from decreasing and improves drivability.
A regeneration controlling routine which is executed by the ECU 50 during manual shift down will now be described with reference to FIG. 13. Periodic interrupting is carried out every predetermined time period to execute the routine.
When the ECU 50 enters this routine, at step S400, the ECU 50 judges whether a manual shift down flag XMSD is set at one. If the manual shift down flag XMSD is set at one, the ECU 50 determines that manual shift down had been carried out in the previous cycle and proceeds to step S430. At step S430, the ECU 50 judges whether the gear is being manually shifted up from a second range (2) to a drive range (D) or from a low range (L) to the second range (2). If it is determined that manual shift up is taking place, the ECU 50 proceeds to step S510 and resets the manual shift down flag XMSD to zero. The ECU 50 then terminates the routine.
If the flag XMSD is set at zero in step S400, the ECU 50 determines that manual shift down had not been carried out in the previous cycle and proceeds to step S410. The manual shift down flag XMSD is initially reset at zero. At step S410, the ECU 50 judges whether the gear is being manually shifted down from the drive range (D) to the second range (2) or from the second range (2) to the low range (L). The shifting is confirmed based on various signals sent from the shift range switch 55 when the gear is shifted to the drive, second, or low range. The ECU 50 compares the data of the signals from the shift range switch 55 in the previous cycle with the data of the signals from the switch 55 in the present cycle to determine whether a shift down has taken place. If a shift down has not taken place, the ECU 50 stops execution of this routine. Contrarily, if a shift down has been performed, the ECU 50 proceeds to step S420 and sets the manual shift down flag XMSD to one.
At step S430, the ECU 50 determines that manual shift up has not been performed. The ECU 50 then proceeds to step 440 and reads the vehicle speed SPD and an acceleration rate α. The acceleration rate α is computed beforehand through a different routine based on the vehicle speed SPD.
At step S450, the ECU 50 obtains the required negative drive torque T o through a map. The map is three-dimensional and includes the vehicle speed SPD, the acceleration rate α, and a negative drive torque. The map is obtained through experiments.
In the subsequent step S460, the ECU 50 judges whether the absolute value of the negative drive torque T o is equal to or smaller than the absolute value of the maximum regeneration torque T M/Gmax . The maximum regeneration torque T M/Gmax is obtained through a different routine.
FIG. 14 illustrates a computing routine that is used to obtain the maximum regeneration torque. The computing routine is executed periodically. Before describing the computing routine, the definition of the maximum regeneration torque T M/Gmax will be given. The condenser, which serves as an electric power source when regeneration controlling is performed, has been charged during the prior regeneration controlling and thus has a voltage V. The maximum voltage that may be obtained through the subsequent regeneration controlling is computed from the difference between the maximum capacitor voltage Vmax of the condenser and the charged voltage V of the condenser. Accordingly, the maximum regeneration torque T M/Gmax is obtained from the present condenser voltage V and the corresponding engine speed N e .
Thus, at step S550, shown in FIG. 14, the ECU 50 compares the present condenser voltage V and the corresponding engine speed N e with a map. The map is three-dimensional and includes the condenser voltage V, the engine speed N e , and the torque. The map is obtained through experiments. The maximum regeneration torque T M/Gmax is obtained from the map. After step 550, the ECU 50 terminates execution of this routine.
Returning to the description of the original routine, if the absolute value of the negative drive torque T o does not exceed the absolute value of the maximum regeneration torque T M/Gmax of the motor-generator 12 in step S460, the ECU 50 proceeds to step S520. If the absolute value of the negative drive torque To exceeds the absolute value of the maximum regeneration torque T M/Gmax of the motor-generator 12, the ECU 50 proceeds to step S470. At step S470, the ECU 50 computes the difference ΔT between the negative drive torque T o and the maximum regeneration torque T M/Gmax . That is, the negative drive torque ΔT of the CVT 21 is computed in this step. In step 480, the target rotating speed N ino is obtained from a three-dimension map, which includes the negative drive torque ΔT, the vehicle speed SPD, and the input shaft rotating speed N in . The map is illustrated in FIG. 5.
In the map shown in FIG. 5, the input rotating speed N in alters with respect to the vehicle speed SPD in accordance with the negative drive torque ΔT. In other words, increase of the vehicle speed SPD results in an increase of the input shaft rotating speed N in . When the vehicle speed SPD is constant and the negative drive torque ΔT is large, or in the case the expression of ΔT1>ΔT2>ΔT3 is satisfied, the negative torque ΔT1 becomes greater than the negative torque ΔT3 with respect to the input shaft rotating speed N in .
At step S490, the ECU 50 controls the shift control valve 58 of the CVT 21 based on the target rotating speed N ino , which was set in step S480. At step S500, the maximum regeneration torque T M/Gmax is set as the first target regeneration torque T1 M/G . At step S530, the controlling electric current I M/G of the motor-generator 12 is obtained from a map stored in the ROM. The map is three-dimensional and includes the engine speed N e , the torque T, and the controlling electric current value I n , which are obtained through experiments. The controlling electric current value I M/G corresponding to the torque T and the engine speed N e are selected from this map.
At step S540, the ECU 50 sends the controlling electric current value I M/G to the stator wire 33 of the motor-generator 12 and performs regeneration controlling of the motor-generator 12. In other words, the motor-generator 12 functions as a generator and regenerates electric current to charge the condenser. Electric power is obtained through the regeneration controlling. However, negative drive torque is consumed to produce the electric power. After step S540, the ECU 50 stops execution of the routine.
Accordingly, by executing steps S470 to S540, the motor-generator 12 produces the maximum regeneration torque T M/Gmax and controls the shifting of the CVT 21 to replenish the insufficient torque. The negative drive torque T o is obtained by controlling both the motor-generator 12 and the CVT 21.
At step 460, if the absolute value of the required negative drive torque To is equal to or lower than the absolute value of the maximum regeneration torque T M/Gmax of the motor-generator 12, the ECU 50 proceeds to step S520. At step 520, the ECU 50 sets the negative drive torque as the first target regeneration T 1M/G and proceeds to step S530. At step S530, the ECU 50 obtains the controlling electric current value I M/G from the map. At step 540, the controlling electric current value I M/G is sent to the motor-generator 12 (stator wire 33) and regeneration controlling of the motor-generator 12 is performed. The ECU then terminates execution of this routine.
Accordingly, execution of steps S520 to S540 produces the negative drive torque T o required by the motor-generator 12. Thus, the shifting of the CVT 21 becomes unnecessary.
At step S460, if the absolute value of the required negative drive torque T o exceeds the absolute value of the maximum regeneration torque T M/Gmax of the motor-generator 12, the ECU 50 carries out steps S470 to S540. Through the steps of S470 to S540, the ECU 50 produces the maximum regeneration torque T M/Gmax and controls shifting of the CVT 21 to replenish the insufficient torque. This suppresses the shift controlling of the CVT 21 and prevents the belt of the CVT 21 from slipping.
A control routine executed by the ECU 50 is shown in FIG. 15. The routine is performed when the CVT 21 is in a state that its speed is constant. The controlling of the CVT 21 will first be described.
The ECU 50 controls the altering of the gear ratio of the CVT 21 based on shift flags that correspond to each shift state. Shift flag DF corresponds to sudden deceleration, shift flag DM corresponds to normal deceleration, shift flag DS corresponds to gradual deceleration, shift flag US corresponds to gradual acceleration, shift flag UM corresponds to normal acceleration, and shift flag UF corresponds to sudden acceleration. The ECU 50 sets these shift flags based on input signals. The CVT 21 is controlled based on the set shift flag. When the speed is constant and shifting is not performed, the ECU 50 alternately sets the shift flag DS and the shift flag US. This controls the CVT 21 to repetitively perform gradual deceleration and gradual acceleration as shown in FIG. 6(b). By repeating acceleration and deceleration, the actual rotating speed N in fluctuates repetitively in a cyclic manner about the target rotating speed N ino . This controls the gear ratio so that it becomes substantially constant.
Periodic interrupting is carried out every predetermined time period to execute the routine illustrated in FIG. 15. When the ECU 50 enters this routine, the ECU 50 determines whether the shift flag DS is set. If the shift flag DS is set, the ECU 50 proceeds to step S630 and performs assist controlling of the motor-generator 12 by sending the predetermined controlling electric current value I M/G to the motor-generator 12. In other words, the motor-generator 12 functions as a motor and produces a predetermined torque T. The predetermined controlling electric current value I M/G is a value prestored in the ROM. The value corresponds to the torque required for assist when gradual deceleration is executed while in a constant speed state.
If the shift flag DS is not set at step S600, the ECU 50 proceeds to step S610 and judges whether the shift flag US is set. At step S610, if it is determined that the shift flag US is not set, the ECU 50 stops executing this routine. If it is determined that the shift flag US is set in step S610, the ECU 50 proceeds to step S620. At step S620, constant regeneration controlling of the motor-generator 12 is performed by sending the controlling electric current value I M/G to the stator wire 33 of the motor-generator 12.
In other words, the motor-generator 12 functions as a generator and regenerates electric power to charge the condenser. By performing the regeneration controlling, electric power is produced. However, drive torque is consumed to produce the electric power. The predetermined controlled electric value I M/G for the regeneration controlling corresponds to the value prestored in the ROM. The torque consumed when performing regeneration controlling during execution of gradual acceleration in a constant speed state is obtained through experiments.
In this routine, execution of steps S600 to S630 results in constant assist controlling of the motor-generator 12 being performed during gradual deceleration and constant regeneration controlling of the motor-generator 12 being performed during gradual acceleration. The constant assist controlling and the constant regeneration controlling are performed regardless of the cyclic fluctuation of the actual rotating speed N in of the CVT 21 due to gradual deceleration and gradual acceleration being carried out repetitively. Thus, the torque fluctuation produced when switching between gradual acceleration and gradual deceleration is suppressed.
A control routine related to the temperature of the hydraulic oil in the motor-generator 12 will now be described with reference to FIG. 16. The purpose of executing this routine will first be described. When the temperature of the hydraulic oil (oil temperature) THO in the hydraulic cylinders 46, 47 is low, the movement of each cylinder 46, 47 is delayed with respect to the required oil pressure of the CVT 21. In other words, as shown in FIG. 8, the oil pressure which pushes the belt 39 becomes delayed initially if the oil temperature is low compared to when the oil temperature is normal. In this routine, regeneration controlling of the motor-generator 12 is performed to reduce engine torque. Accordingly, the torque sent to the CVT 21 is reduced and oil pressure becomes sufficient.
When entering this routine, the ECU 50 judges whether an initial oil temperature flag XCLD is set at one. If set at one, the ECU 50 proceeds to step S750. If the flag XCLD is set at zero, the ECU 50 proceeds to step S710 and judges whether the oil temperature THO is lower than a predetermined reference oil temperature THOCLD. If the oil temperature THO is equal to or higher than the reference oil temperature THOCLD, the ECU 50 proceeds to step S820 and resets the flag XCLD to zero. The execution of this routine is then terminated.
The reference oil temperature THOCLD corresponds to a lower limit that ensures normal functioning of the hydraulic oil. The value of the reference oil temperature THOCLD is obtained through experiments.
If it is determined that the oil temperature THO is lower than the reference oil temperature THOCLD in step S710, the ECU 50 proceeds to step S720. At step S720, the ECU 50 determines whether the difference between the present throttle angle THR i and the throttle angle THR.sub.(i-1) in the previous cycle is equal to or greater than zero, or in an accelerating state. If the difference between the present throttle angle THR i and the throttle angle THR.sub.(i-1) in the previous cycle is smaller than zero, or in an decelerating state, the ECU 50 terminates execution of this routine. If the difference between the present throttle angle THR i and the throttle angle THR.sub.(i-1) in the previous cycle is equal to or greater than zero, this indicates an accelerating state. In this case, the ECU 50 proceeds to step S730 and sets the present throttle angle THR as the initial throttle angle value THRO. The ECU 50 also sets the present corresponding engine speed N e as the initial engine speed value N eo . The ECU 50 then proceeds to step S740 and sets the initial oil temperature flag XCLD to one.
Steps S710 to S740 are executed if the initial oil temperature flag XCLD is not first set at zero. Accordingly, if the flag XCLD is set at one in the previous cycle, the ECU 50 jumps from step S700 to step S750.
At step S750, an engine torque T e is obtained through a map that is three-dimensional and includes the engine speed N e , the operating state corresponding to the throttle angle THR, and the engine torque T e . The three-dimensional map is obtained through experiments and is stored in the ROM. In step S750, the ECU 50 further obtains an initial engine torque T eo through a map that is three-dimensional and consists of the initial engine speed value N eo , the initial throttle angle value THRO, and the engine torque Te. The map is obtained through experiments and experiments, and stored in the ROM.
At step S760, a first delay caused by the controlling of the engine torque is computed through the next equation.
T.sub.e =T.sub.e (T.sub.e -T.sub.ea) (1-e.sup.-t/t1)
In the above equation, t1 represents an engine onset time constant and is obtained through experiments. The value of t1 is a characteristic value of the engine 11.
At step S770, a first delay caused by controlling the CVT transmission torque T ecv of the CVT 21 is computed through the next equation:
T.sub.ecv =(T.sub.e -T.sub.ea) (1-e.sup.t/t2)
In the above equation, t2 represents a hydraulic pressure onset time constant and is obtained through experiments. The value of t2 is a characteristic value of the CVT 21. The above two equations are both approximate expressions.
At step S780, the difference between the first delay T ecv of the CVT 21 and the first delay of the engine torque, or the second target regeneration torque T2 M/G is computed from the next equation.
T2.sub.M/G =T.sub.ecv -T.sub.e
At step S790, the ECU 50 compares the second target regeneration torque T2 M/G with a reference regeneration torque T min . The reference regeneration torque T min is referred to in order to determine whether regeneration controlling should be performed in the following steps. If the second target regeneration torque T2 M/G is equal to or lower than the reference regeneration torque T min , the second target regeneration torque T2 M/G is so small that regeneration controlling of the motor-generator 12 is not necessary. In other words, the difference between the first delay T ecv of the CVT 21 and the first delay of the engine torque is small. Thus, the ECU 50 terminates execution of this routine. If the second target regeneration torque T2 M/G exceeds the reference regeneration torque T min there is a necessity to perform regeneration controlling of the motor-generator 12.
At step S800, the ECU 50 obtains the controlled electric value I M/G from a map stored in the ROM. The map is three-dimensional and includes the engine speed N e , a torque T, and a controlling electric current value In. This map is obtained through experiments. At step S810, the ECU 50 sends the controlling electric current value I M/G to the motor-generator 12 (the stator wire 33) and performs regeneration controlling of the motor-generator. That is, the motor-generator 12 functions as a generator and regenerates electric current. Although electric power is obtained by performing the regeneration controlling, engine torque is consumed to obtain the electric power. The area indicated by slanted lines in FIG. 8 shows the consumed engine torque. The ECU 50 terminates execution of this routine after step S810.
The regeneration controlling continues as long as the oil temperature THO of the hydraulic oil in the hydraulic cylinders 46, 47 of the CVT 21 is lower than the reference oil temperature THOCLD and the acceleration state continues. When the oil temperature THO becomes higher than the reference oil temperature THOCLD, the regeneration controlling of the motor-generator 12 is terminated.
When the input torque of the CVT 21 is smaller than the engine torque, the belt 39 of the CVT 21 has a tendency to slip. However, this routine reduces the engine torque and thus suppresses slipping of the belt 39. The suppression of the slipping of the belt 39 eliminates transmission loss of torque and thus improves energy efficiency.
Although only one embodiment of the present invention has been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. For example, the present invention may be modified as described below. (A) Instead of the condenser, the battery may be used as the electric power source for performing assist controlling and regeneration controlling of the motor-generator 12. (B) The altering rate of the actual rotating speed of the engine and the CVT 21 are computed in steps S70 and S160. However, it is not required to compute the altering rate of both the engine and the CVT 21 as long as either one of the two are computed. (C) At step S770, t2 represents the hydraulic pressure onset time constant and is a characteristic value of the CVT 21. Thus, t2 is a fixed value. However, the value of t2 may be changed in accordance to the oil temperature. By changing the value of t2 in accordance with the oil temperature, regeneration controlling becomes more accurate.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
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A control apparatus for a vehicle includes a power transmitting system between an engine and wheels. The transmitting system has a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode. The motor-generator serves as a generator in a regenerating operation mode and as a motor in an assisting operation mode. The apparatus includes an electric control unit (ECU) that determines a shift of engine speed, computes the total amount of torque of the engine, the CVT and the motor-generator and selects one of the operation modes and actuates the motor-generator base on the selected operation mode to corrects the engine speed.
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CROSS-REFERENCE TO PRIOR APPLICATIONS
This application is the U.S. National Phase application under 35 U.S.C. §371 of International Application Serial No. PCT/IB2013/053479, filed on May 2, 2013, which claims the benefit of U.S. Provisional Application Ser. No. 61/645,097, filed on May 10, 2012. These applications are hereby incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to gesture control systems and methods. Especially the present invention relates to gesture control systems and method for use in health care institutions.
BACKGROUND OF THE INVENTION
Interacting with computers can be done in a number of ways, including using a mouse or keyboard. In some situations, however, it is preferable to use a touch-free control unit. Such a control system could be a voice controlled system, but voice control is not always sufficiently accurate and precise. The inventor of the present invention has appreciated that an improved control system and method is of benefit, and has in consequence devised the present invention.
SUMMARY OF THE INVENTION
Robustness of systems for controlling imaging systems and other medical devices using operator gestures depends on the volume of sensor data and the type of sensor. Current gesture control methods have drawbacks, e.g., a camera-based system needs a line-of-sight and an ultrasound based system is useful only for short range. Another limiting factor is that for most sensor approaches, it is difficult to track, for example, an operator's entire arm.
The present invention proposes a garment enabled with optical shape sensing that tracks, amongst other things, extremities of an operator, e.g. arms, head, hands, fingers, or any optical shape sensing enabled device, preferably in combination with a system, wherein a pattern recognition scheme is applied to evaluate the recorded gestures for event detection in real-time.
It would be advantageous to achieve a control system where touch-free control allows precise and robust inputs to a device, e.g. a computer.
In general, the invention preferably seeks to mitigate, alleviate or eliminate one or more of the above mentioned disadvantages singly or in any combination. In particular, it may be seen as an object of the present invention to provide a method that solves the above mentioned problems, or other problems, of the prior art.
To better address one or more of these concerns, in a first aspect of the invention a garment to be worn by a person, e.g. a health care person, to be monitored is presented that comprises an optical shape sensing device affixed to and running throughout the garment so that shape changes and/or movement of a part of the garment is reflected as a shape change in the optical shape sensing device, wherein the optical shape sensing device is sewed up in, or affixed to, the garment so as to monitor motion.
By utilizing a garment having a trackable shape sensing device embedded or affixed to the garment the drawbacks of a camera-based system needing a line-of-sight and an ultrasound-based system being useful for short range only, are eliminated. Another limiting factor which is overcome is that for most sensor approaches, it is difficult to track, for example, an operator's entire arm. By the present invention it is possible to track an entire arm. This allows for a more precise recognition of gestures. Further, it is contemplated that gesture commands may include movement of more parts of the arm, e.g. combined by upper and lower arm and/or hand. The garment allows monitoring of a person wearing the garment in a robust way. The garment provides possibility of recognition of movement patterns of the person wearing the garment whereby the person is allowed to interact with equipment in a touch-free way.
Using the garment, or the instrument, it is possible to control a range of equipment including, but not limited to, an imaging system, e.g. allowing the wearer to change or manipulate images being displayed, a surgical instrument, for instance a catheter or interventional or surgical probe or robot or an injector for contrast agent, a data set being displayed on a screen or any other instrument or equipment that a surgeon may wish to operate in an easy and intuitive manner without having to touch the device to control it. More examples will be given below.
The present invention may also include audio and/or visual and/or haptic feedback to confirm gesture interpretation and command execution. Further, the system, garment, instrument and method may employ a mode switch so as to toggle gesture control state on and off during an intervention. Also a confirmation step may be used before a recognized command is executed.
When using the garment in a health care institution, especially in a surgical setting, the garment provides intuitive control, and improved workflow due to reduced interaction with the clinical staff handling viewing workstations. It is currently imagined that the system is well suited for examples in medical imaging which in general includes image browsers controlled by gestures. This could e.g. be prerecorded pre-interventional imaging including but not limited to CT, MR, X-ray, Ultrasound imaging or live X-ray images, MR-images, CT images, ultra sound images of a patient undergoing, or scheduled to undergo, surgery or other medical procedure.
In an embodiment the optical shape sensing device comprises a flexible body having a cross-section being comparatively small relative to the length of the device, the optical shape sensing device configured to determine the shape of the flexible body relative to a reference, the shape sensing device configured to collect information based on its configuration to track movement and/or current shape of the flexible body. When the optical shape sensing device comprises a flexible body, the optical shape sensing device is able to follow the movements of the person wearing the garment while having an increased strength.
Advantageously the optical shape sensing device is integrated in a part of the garment corresponding to an extremity of a person wearing the garment. As mentioned above it is contemplated to be especially useful to integrate the optical shape sensing device in an extremity as these are the most efficient to move purposely. Extremities include arms, head, hands and/or one or more fingers. Tracking the torso of a person alone could yield detection of unintended movement patterns corresponding to a given command or event. Combining movement pattern recognition of torso and one or more extremities provides a wider range of combination s allowing more commands or events to be defined. Tracking at least one extremity allow for an intuitive control of the device to be controlled.
In an embodiment the garment is a surgical gown and the optical shape sensing device is located in one arm of the surgical gown. The integration of the optical shape sensing device in a garment for use in surgical gowns is especially useful as in such settings the need for reducing contact to maintain sterility is quite high. Eliminating contact between the surgeon and any equipment reduces the risk of contamination, e.g. from insufficient cleaning of the equipment.
Advantageously the garment may comprise a connector for connecting the optical shape sensing device to a control computing device generating gesture events based on position information from the optical shape sensing device. The garment is advantageously used for generating commands or instructions for a computing device, e.g. an imaging device for use in a surgical setting.
A second aspect relates to a surgical instrument comprising an optical shape sensing device disposed within the surgical instrument and configured to determine a shape and/or position of the surgical instrument relative to a reference, the optical shape sensing device configured to collect information based on its configuration to during a procedure. Gestures may be detected based on detecting maneuvers of tracked medical devices, such as surgical instruments including but not limited to a shape sensing enabled catheter, which for instance could be used to trigger an infusion if the physician performs specific actions. An example could be a clockwise rotation by 180 degrees or fast movements detectable by applying pattern recognition. The optical shape sensing device may in this relation also be an optical position sensing device.
Advantageously the surgical instrument may be a flexible instrument including a catheter and/or a guidewire.
In an embodiment the surgical instrument may comprise a connector for connecting to a control computing device generating gesture events based on position information from the optical shape sensing device. The surgical instrument may be connected directly to a control computing device performing gesture pattern recognition or be connected to a garment according to the first aspect of the present invention so that a system for pattern recognition correlates patterns recorded for the surgical instrument with patterns detected using the garment.
A third aspect of the present invention relates to a gesture pattern recognition system comprising a garment to be worn by a human to be monitored, the garment comprising: an optical shape sensing device affixed to and running throughout the garment so that shape changes and/or movement of a part of the garment is reflected as a shape change in the optical shape sensing device, wherein the optical shape sensing device is sewed up in, or affixed to, the garment so as to monitor motion, the shape gesture pattern recognition system receiving a signal from the optical shape sensing device and the shape gesture pattern recognition system generating a gesture event based on the signal from the optical shape sensing device. The optical shape sensing device allow for tracking of movement of the person wearing the garment and the system as a whole may then be used for monitoring if/when the person wish to issue a command or instruction to a computing device, such as an image display device. The system provides accurate and robust monitoring of movement without limitations of line of sight.
A fourth aspect of the present invention relates to a gesture pattern recognition system comprising a surgical instrument comprising an optical shape sensing device disposed within the surgical instrument and configured to determine a shape and/or position of the surgical instrument relative to a reference, the optical shape sensing device connected to the shape gesture pattern recognition system to collect information based on a signal from the optical shape sensing device relating to the configuration of the instrument to during a procedure, the shape gesture pattern recognition system creating gesture events based on the signal. The optical shape sensing device is used for monitoring movement of the surgical instrument. The person operating the surgical instrument may wish to issue a command to create a gesture event. As an example a shape sensing enabled catheter could be used to trigger an infusion if the physician performs specific actions such as clockwise rotation by 180 degrees or fast movements detectable by using a system according to the applying pattern recognition
A fifth aspect of the present invention relates to a method for controlling a shape gesture pattern recognition system comprising an object with an optical shape sensing device, wherein the shape gesture pattern recognition system is configured to determine a shape and/or position of the object relative to a reference, the method comprising the steps of detecting a gesture pattern of the object, determining if the gesture pattern of the object corresponds to one of a set of recognized gestures, if the gesture pattern is recognized generating a gesture event based on the recognized gesture, and operating a device based on the gesture event. The method allows monitoring of a person wearing a garment having an optical shape sensing device. The method provides recognition of movement patterns of the person wearing the garment whereby the person is allowed to interact with equipment in a touch-free way. The method may advantageously be used in connection with the devices and systems mentioned in relation to the other aspects of the present invention.
Advantageously the object is a garment and the optical shape sensing device is integrated or affixed to the garment, the method may then comprise detecting gesture patters of the person wearing the garment. The gesture patterns are used for generating gesture events which in turn is used for controlling a device. The device could be an imaging device as described elsewhere.
Advantageously when the object is a surgical instrument comprising an optical shape sensing device disposed within the surgical instrument and configured to determine a shape and/or position of the surgical instrument relative to a reference, the optical shape sensing device may be configured to collect information based on its configuration to during a procedure. When applying the method to a surgical instrument the method allows the operator of the instrument to issue touch-free commands. The commands could relate to a shape sensing enabled catheter to trigger an infusion via the catheter.
Advantageously detecting the gesture pattern may include detecting discrete events and/or quantitative metrics including velocity and/or acceleration. By applying discrete events, e.g. detecting that an arm moves in a specific manner or movement pattern of a hand, the method allows definition of movements that are not usually part of the operators normal behavior. The same apply to detection of quantitative metrics.
Advantageously detecting discrete events may include detecting motion of extremities of a person wearing the object. As mentioned the method may advantageously focus on the movement of an extremity, or several extremities, e.g. arm, leg, hand, finger, head or combinations thereof.
In all of the above aspects the following may apply to the optical shape sensing device.
Advantageously the optical shape sensing device may include an optical fiber having at least one of Fibre Bragg Gratings (FBGs) and/or a Rayleigh scatter interrogation setup for sensing strain in the fibre. The use of optical fibre or optical fibres allow for the device to be flexible. Other suitable materials or structures may be envisioned.
Advantageously the optical shape sensing device includes an area of higher sensitivity by including an area with a higher number of optical fibres having optical strain sensors. E.g. optical shape sensing device may have one area where one number of optical fibres having optical strain sensors are present, in another are another number of optical fibres having optical strain sensors is present, and thus an area having of higher sensitivity may be established. The higher sensitivity may help achieve a better resolution on the determination of the position of the device. It may be advantageous to have an area having one optical fibre having optical strain sensors defining an area having a first sensitivity, and another area having four optical fibres having optical strain sensors defining an area having a second sensitivity being higher than the first sensitivity.
Advantageously the optical shape sensing device may include one, or more, of a spiral shape, a ring shape, a straight or curved line and/or a loop shape. The different devises provide different effects e.g. better fitting to a specific organ and/or tumour, and the specific choice may depend on the intended clinical application.
In general the various aspects of the invention may be combined and coupled in any way possible within the scope of the invention. These and other aspects, features and/or advantages of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be described, by way of example only, with reference to the drawings, in which
FIG. 1 is a schematic illustration of a principle used in the present invention,
FIG. 2 is a schematic illustration of a health care setting,
FIG. 3 is a schematic illustration of a system including a surgical instrument,
FIG. 4 is a schematic illustration of a system including a garment, and
FIG. 5 is a schematic illustration of steps of a method according to the present invention.
DESCRIPTION OF EMBODIMENTS
Gesture control is gaining attention in the medical market due to advantages such as touch-free control, which is important for maintaining sterility, intuitive control, improved workflow and the like. Gesture control robustness, however, depends on the amount of sensor data and the type of sensor: e.g a camera-based system suffers line-of-sight issues. That is to say, the camera must have an unobstructed view on the tracked object, e.g. the arm or hand of a person. An ultrasound based system is useful only for short range applications. For most sensor approaches it is difficult to track, for example, the entire arm of an operator.
FIG. 1 schematically illustrates one principle used in the present invention where an optical fiber is used as an optical shape sensing device. In practice, optical fiber 20 may be any type of optical fiber suitable for optically tracking elongated device. Examples of optical fiber 20 include, but are not limited to, a flexible optically transparent glass or plastic fiber incorporating an array of fiber Bragg gratings integrated along a length of the fiber as known in the art, and a flexible optically transparent glass or plastic fiber having naturally variations in its optic refractive index occurring along a length of the fiber as known in the art (e.g., a Rayleigh scattering based optical fiber). Optical fiber 20 may be a single core fiber or preferably, a multi-core fiber.
Overall FIG. 1 schematically illustrates the principles of a system 10 for optical frequency domain reflectometry using a tuneable light source 30 and a fiber-optic interferometer. The output of the light source 30 travels through a splitter 40 which directs a part of the signal into a reference arm 50 and the remaining part of the signal into a sample arm 60 which illuminates and receives the light reflected at the area 70 .
The interference between the signal returned from the reference arm and the signal returned from the sample-arm is detected with a square-law photo detector 80 while the wavelength of the monochromatic source is swept and the path lengths of the reference and sample arm are held constant. The axial reflectivity profile (A-line) is obtained by discrete Fourier transform (DFT) of the sampled detector signals.
In practice, elongated device 20 may be any type of device suitable for embedding an optical fiber therein for purposes of optically tracking the elongated device. Examples of elongated device 20 include, but are not limited to, an endoscope of any type, a catheter and a guide wire. Further the elongated device 20 may be embedded or attached to a garment.
In practice, optical interrogation console 30 , including the light source, may be any device or system structurally configured for transmitting light to optical fiber 20 or 60 and receiving reflected light from optical fiber 20 or 60 . In one embodiment, optical interrogation console 30 employs an optical Fourier domain reflectometer and other appropriate electronics/devices as known in the art.
FIG. 2 schematically illustrates a garment 100 worn by a health care person to be monitored. The garment 100 comprises an optical shape sensing device 110 affixed to and running throughout the garment 100 so that shape changes and/or movement of a part of the garment 100 is reflected as a shape change in the optical shape sensing device 110 , wherein the optical shape sensing device 110 is sewed up in, or affixed to, the garment 100 so as to monitor motion. This allows unobstructed monitoring of the person using the garment 100 whereby detection of specific movement patters is possible. In FIG. 2 the garment 100 is a surgical gown and the optical shape sensing device 110 is located in one arm of the surgical gown.
Fiber-optic shape sensing 110 when contained in a flexible substrate such as textile of a garment can be used to track gestures of an operator wearing the sensing enabled garment. If the shape sensor is embedded e.g. in the arm sleeve of the operating apron, the entire arm can be tracked without any sensor limitation such as line-of-sight, or operating field size.
The relative accuracy of Optical Shape Sensing (OSS) is good enough even at extended tether lengths of more than three meters for gesture control and movement pattern recognition, allowing for enough cable length to connect garment 100 . The garment 100 may be connected to equipment via the operating table 120 or directly to a control system. Preferably the connection is via a cable 130 as there may be risks involved when using a wireless connection, but it is not excluded that the garment 100 , or optical shape sensing device 110 , may be connected wirelessly.
Another advantage of optical shape sensing especially compared to the more established Time Of Flight (TOF) technology is that even small deformation can be tracked. This is particularly important as one current problem of TOF based gesture control is that large movements have to be performed to do the control which is difficult to accept in the operating room. This is not always desirable in operating theaters.
The optical shape sensing device 110 comprises a flexible body having a cross-section being comparatively small relative to the length of the device, and the optical shape sensing device 110 is configured to determine a shape of flexible body relative to a reference, the shape sensing device 110 configured to collect information based on its configuration to track movement and/or current shape of the flexible body. This is also possible via the arrangement illustrated in FIG. 1 .
Gestures can also be detected based on detecting maneuvers of tracked medical devices. E.g. a shape sensing enabled catheter could be used to trigger an infusion if the physician performs specific actions such as clockwise rotation by 180 degrees or fast movements detectable by applying pattern recognition approaches. FIG. 3 is a schematic illustration of a surgical instrument 200 comprising an optical shape sensing device 210 disposed within the surgical instrument 200 and configured to determine a shape and/or position of the surgical instrument 200 relative to a reference, the optical shape sensing device 200 configured to collect information based on its configuration to during a procedure.
In an advantageous embodiment the surgical instrument 200 is a flexible instrument including a catheter and/or a guidewire. Such instruments are commonly used by surgeons and the added feature of being able to control functions of the instrument without having to let go of the instrument is an improvement of the safety when operating.
As with the garment 100 , the surgical instrument 200 further comprises a connector for connecting to a control computing device 230 generating gesture events based on position information from the optical shape sensing device. Preferably the instrument 200 is connected to a system via a cable 240 .
For further improvement of safety is it possible to restrict the system so that the shape sensing 210 can be used for identification purposes: e.g. only when the tracked hand of the interventional cardiologist holds the end of a tracked ablation catheter the ablation procedure can be activated while all other personnel touching the catheter cannot activate it.
FIG. 4 schematically illustrates a gesture pattern recognition system 300 comprising a garment 310 to be worn by a human to be monitored, the garment 310 comprising an optical shape sensing device 320 affixed to and running throughout the garment 310 so that shape changes and/or movements of a part of the garment 310 are reflected as shape changes in the optical shape sensing device 320 , wherein the optical shape sensing device 320 are sewed up in, or affixed to, the garment 310 so as to monitor motion, the shape gesture pattern recognition system 300 comprising a processor 330 receiving a signal from the optical shape sensing device 320 and the shape gesture pattern recognition system 300 generating a gesture event based on the signal from the optical shape sensing device 320 .
The system is especially suitable for use in a surgical room setting. The optical shape sensing device 320 allows for tracking of movement of the person wearing the garment 310 and the system as a whole may then be used for monitoring if/when the person wishes to issue a command or instruction to a computing device, such as an image display device. The system 300 provides accurate and robust monitoring of movement without limitations of line of sight.
A similar system may be defined, with reference FIG. 3 , wherein a surgical instrument 200 comprising an optical shape sensing device 210 disposed within the surgical instrument 200 and configured to determine a shape and/or position of the surgical instrument 200 relative to a reference, is used. The optical shape sensing 210 device is then connected 240 to a processor 230 in the shape gesture pattern recognition system to collect information based on a signal from the optical shape sensing device 210 relating to the configuration of the instrument 200 to during a procedure, the shape gesture pattern recognition system creating gesture events based on the signal. The person using the system may then issue commands to the pattern recognition system so as to operate further functions in the instrument or an external system such as an image viewing system.
FIG. 5 schematically illustrates steps of a method 400 for controlling a gesture pattern recognition system comprising an object with an optical shape sensing device, wherein the shape gesture pattern recognition system is configured to determine a shape and/or position of the object relative to a reference, the method comprising the steps of detecting 410 a gesture pattern of the object, determining 420 if the gesture pattern of the object corresponds to one of a set of recognized gestures, if the gesture pattern is recognized generating a gesture event based on the recognized gesture, and operating 430 a device based on the gesture event.
The method may be used in connection with a garment 310 and the optical shape sensing device 320 is then integrated or affixed to the garment 310 , the method may then further comprise detecting gesture patters of the person wearing the garment.
Alternatively the method 400 may be used in connection with a surgical instrument 200 comprising an optical shape sensing device 210 disposed within the surgical instrument and configured to determine a shape and/or position of the surgical instrument relative to a reference, the optical shape sensing device configured to collect information based on its configuration to during a procedure.
All embodiments described herein may further comprise a further step or device for initiating the gesture control. This could e.g. be a voice recognition system for detecting when an intended command is to be issued by the person wearing the garment or operating the instrument. This allows for improved security as the system or method will not misinterpret movements not related to a command as actual commands.
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.
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The present invention relates to devices, system and method for detecting gestures. The devices, systems and methods uses optically shape sensing devices for tracking and monitoring users. This allows unhindered, robust tracking of persons in different setting. The devices, systems and methods are especially useful in health care institutions.
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RELATED APPLICATION
[0001] This application claims priority to and is a continuation application of U.S. application Ser. No. 14/336,232 filed Jul. 21, 2014, which claims priority to and is a continuation of U.S. application Ser. No. 12/878,522 (now U.S. Pat. No. 8,802,734), filed Sep. 9, 2010, which claims priority under 35 U.S.C. §119(e) to U.S. provisional application Ser. No. 61/240,841, filed Sep. 9, 2009. The disclosures of the above referenced applications are incorporated herein by reference in their entireties.
BACKGROUND
[0002] The present invention relates to the treatment or prophylaxis of pain and provides a method of treating or preventing pain as well as the use of certain compounds in the manufacture of medicaments for the treatment or prophylaxis of pain in humans and non-human animals. Pain is a multifaceted or multidimensional, experiential response to a variety of stimulus conditions. Pain is defined by the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”.
[0003] Pain in animals is frequently the result of nociception, i.e., activity in the nervous system that results from the stimulation of nociceptors. Neuropathic pain differs from nociceptive pain in that it involves damage to the nerve resulting in the sensation of pain. In central pain, the pain is generated in the brain from some form of lesion. Occasionally pain may be psychogenic, i.e., caused by mental illness.
[0004] Pain can be acute or chronic. Acute pain is usually caused by soft tissue damage, infection and/or inflammation among other causes. Acute pain serves to alert after an injury or malfunction of the body. Chronic pain may have no apparent cause or may be caused by a developing illness or imbalance. Chronic pain is defined as the disease of pain; its origin, duration, intensity and specific symptoms may vary.
[0005] The experience of physiological pain can be grouped according to the source and related nociceptors. Cutaneous pain is caused by injury to the skin or superficial tissues. Cutaneous nociceptors terminate just below the skin, and due to the high concentration of nerve endings, produce a well-defined, localised pain of short duration. Examples of injuries that produce cutaneous pain include paper cuts, minor cuts, minor (first-degree) burns and lacerations. Somatic pain originates from ligaments, tendons, bones, blood vessels and nerves. It is detected with somatic nociceptors. The scarcity of pain receptors in these areas produces a dull, poorly-localised pain of longer duration than cutaneous pain; examples include sprains and broken bones. Myofascial pain is usually caused by trigger points in muscles, tendons and fascia and may be local or referred. Visceral pain originates from the body's viscera or organs. Visceral nociceptors are located within body organs and internal cavities. The even greater scarcity of nociceptors in these areas produces pain that is usually more aching and for longer duration than somatic pain. Visceral pain is extremely difficult to localise, and several injuries to visceral tissue exhibit “referred” pain, where the sensation is localised to an area completely unrelated to the site of injury. Phantom limb pain, a type of referred pain, is the sensation of pain from a limb that has been lost or for which a person no longer receives physical signals. Neuropathic pain may occur as a result of injury or disease to the nerve tissue itself. This can disrupt the ability of the sensory nerves to transmit correct information to the thalamus, and hence the brain interprets painful stimuli even though there is no obvious unknown psychological cause for the pain.
[0006] Acute pain is usually treated simultaneously with pharmaceuticals or appropriate techniques for removing the cause and pharmaceuticals or appropriate techniques for controlling the pain sensation, commonly analgesics.
[0007] Analgesics fall into three categories: opioid (narcotic) analgesics, non-opioid analgesics and adjuvant analgesics. Opioid analgesics are powerful analgesics that are chemically related to morphine. However, opioids have many side effects, which may be more likely to occur in people with certain disorders: kidney failure, a liver disorder, chronic obstructive pulmonary disease (COPD), dementia or another brain disorder. Drowsiness, constipation, nausea, vomiting and itching are common when opioids are started. Apart from morphine, opioid analgesics known at the time of writing include codeine, fentanyl, hydrocodone, hydromorphone, levorphanol, meperidine, methadone, oxycodone, oxymorphone, pentazocine and propoxyphene.
[0008] A variety of non-opioid analgesics are also available at the time of writing. They are often effective for mild to moderate pain. Most non-opioid analgesics are classified as non-steroidal anti-inflammatory drugs (NSAIDs). An example of an analgesic that is not an NSAID is acetaminophen, which is commonly known as paracetamol. Acetaminophen has substantially no anti-inflammatory properties.
[0009] NSAIDs are used to treat mild to moderate pain and may be combined with opioids to treat moderate to severe pain. NSAIDs not only relieve pain, but they also reduce the inflammation that often accompanies and worsens pain. Although widely used, NSAIDs can also have side effects, sometimes serious ones, including problems in the digestive tract, bleeding problems, problems related to retaining fluids and increased risk of heart and blood vessel disorders. Current NSAIDs include aspirin, ibuprofen, ketoprofen, naproxen, cox-2 inhibitors such as celecoxib, choline magnesium trisalicylate, diflunisal, salsalate, diclofenac, etodolac, fenoprofen, flurbiprofen, indomethacin, ketorolac, meclofenamate, mefenamic acid, meloxicam, nabumetone, oxaprozin, piroxicam, sulindac and tolmetin.
[0010] Adjuvant analgesics include antidepressants such, for example, as imipramine, amitriptyline, bupropion, desipramine, fluoxetine and venlafaxine; anticonvulsants (such as carbamazepine, gabapentin and pregabalin) and oral and topical local anaesthetics.
[0011] In the treatment of chronic pain, the “Three-Step Analgesic Ladder” developed by the World Health Organization is often used. For mild pain, acetaminophen, aspirin or other NSAIDs may be employed. For mild to moderate pain, week opioids such as codeine and dihydrocodeine are employed in combination with acetaminophen, aspirin or other NSAIDs. In the case of moderate to severe pain, strong opioids such as morphine, diamorphine, or fentanyl, hydromorphone, methadone, oxycodone or phenazocine may be administered in combination with acetaminophen, aspirin or other NSAIDs.
SUMMARY OF THE INVENTION
[0012] An object to the present invention is to provide alternative compounds for the treatment or prophylaxis of pain. In particular, it is object to the present invention to provide alternative NSAIDs for the treatment or prophylaxis of pain and to reduce inflammation. Desirably the compounds of the invention should have no or substantially no adverse activity on the central nervous system.
[0013] Another object of the present invention is to provide an alternative method for the treatment or prevention of pain.
[0014] According to one aspect of the present invention therefore there are provided compounds for use in the treatment or prevention of pain, which compounds may be represented by general formula I below:
[0000]
[0000] in which:
[0015] represents a single or a double bond; and R 5 and R 5 ′ are independently —H, —OH or —OR 6 , where R 6 is a linear or branched C 1 -C 4 alkyl;
X is —CH 2 O—,
[0016] Z is —CH 2 CH 2 O—, —CH(CH 3 )CH 2 O— or —CH 2 CH(CH 3 )O—; m is 1; and n is an integer of 1-5, preferably n is 1 or 2.
[0017] Suitably, said compounds may be the S-enantiomers of the compounds represented by formula I above. The inventioii also comprehends the use of the respective pharmaceutically acceptable salts, prodrugs, metabolites, and hydrates of the compounds of formula I.
[0018] The compounds of the present invention may be used for the treatment or prophylaxis of acute or chronic pain. For instance, the compounds may be used for the treatment of nociceptive pain such, for example, as cutaneous pain, somatic pain, myofascial pain, visceral pain, phantom limb pain or neuropathic pain. The compounds of the invention may also be used treatment of headaches or migraine. The compounds may be used alone or in combination with acetaminophen or another NSAID for the treatment of mild chronic pain or in conjunction with weak or strong opioids for the treatment of moderate or severe pain.
[0019] The compounds of the invention may also be employed in the treatment or prophylaxis of neuropathic pain and maybe used in conjunction with one or more antidepressants or antiepileptic medicaments such, for example, as gabapentin or pregabalin.
[0020] According to another aspect of the present invention therefore there is provided a method for treating or preventing pain in a human or non-human animal patient, which method comprises administering to said patient in need thereof a therapeutic effective amount of one or more of the compounds of the invention.
[0021] For a human patient, a daily dose of 1.0 mg to 15 g of said one or more compounds in a pure, substantially pure or partially pure form as described in more detail below may suitably be administered. The compounds may be administered under the supervision of a medical practitioner in an amount sufficient to achieve effective pain management. In some embodiments, the daily dose of said one or more compounds may be titrated to determine such effective amount. Said daily dose may comprise about 5.0 mg to 1 g, typically about 5 mg to 500 mg. In some embodiments, said dose may comprise 10 mg to 100 mg per day of said one or more compounds. The compounds may be administered on a regimen of one to four times per day.
[0022] Said one or more compounds may be administered parenterally, transdermally, intramuscularly, intravenously, intradermally, intranasally, subcutaneously, intraperitoneally, intraventricularly or rectally. Preferably, the one or more compounds are administered orally. Optionally, the one or more compounds of the present invention may be administered simultaneously, scquentially or separately with at least one opioid analgesic, an antidepressant or an antiepileptic medicament. Alternatively, the one or more compounds of the invention may be administered simultaneously, sequentially or separately with one or more other NSAIDs or acetaminophen.
[0023] In yet another aspect of the present invention there is provided the use of one or more of the compounds of the invention in the manufacture of a medicament for use in the treatment or prophylaxis of pain. Said medicament may be manufactured for co-administration with one or more of acetaminophen, another NSAID, an opioid, an antiepileptic or an antidepressant. Advantageously, it has been found that the compounds of the present invention are effective for reducing or preventing inflammation. It has also been found that the compounds of the invention have no or substantially no (i.e., within acceptable limits) deleterious effect on the central nervous system.
[0024] As mentioned above, n may be 1, 2, 3, 4, or 5, preferably 1 to 2.
[0025] In some embodiments of the invention, the compounds of the invention may be represented by general formula II below:
[0000]
[0000] in which , n, Z, R 5 and R 5 ′ are as defined above.
Z may be —CH 2 CH(CH 3 )O—.
Z may be —CH(CH 3 )CH 2 O—.
[0026] In some embodiments of the present invention, the compounds of the invention may therefore be represented by general formula III below:
[0000]
[0000] in which n, R 5 and R 5 ′ are as defined above.
R 5 may be H. Alternatively, R 5 may be OH.
R 5 ′ may be H. Alternatively, R 5 ′ may be OH.
[0027] Suitably, n1 may be an integer from 1-5, preferably 1-3, more preferably 1-2. For example, n may be 1, 2, 3, 4 or 5. Advantageously, n may be 1-2, e.g., 1.
[0028] Alternatively, the compounds of the invention may be the S-enantiomers of the compounds represented by general formulae IV, V, VI and VII below:
[0000]
[0000] in which R is a polyalkylene glycol polymer having n units, wherein n is as defined above, particularly n=1, 2, 3, 4, or 5.
[0029] Suitably, said polyalkylene glycol polymer may be polyisopropylene glycol.
[0030] In a preferred aspect, the compounds of the invention are a compound of formula VII, more preferably a compound having one of the following formulas.
[0000]
[0031] All chiral, diastereomeric, racemic, and geometric isomeric forms of a structure are intended, unless specific stereochemistry or isomeric form is specifically indicated. For example, for compound 2, the following isomeric forms are intended:
[0000]
[0032] For example, some isomeric forms of compound 1 are shown below:
[0000]
[0033] Isomeric forms of compound 1 also include geometric isomers as shown below, including all R and S permutations:
[0000]
[0034] For example, some isomeric forms of compound 3 (NRD 175) are shown below:
[0000]
[0035] Suitable synthetic methods for obtaining and purifying the compounds of the present invention are disclosed in detail below. However, it should be apparent to a person skilled in the art that the compounds may be prepared using any other feasible synthetic methods.
[0036] The compounds of the invention may be synthesised as polyalkylene glycol (PAG) conjugates. Polymers that may be used for such conjugation include poly(ethylene glycol) (PEG), also known as or poly(ethylene oxide) (PEO) and polypropylene glycol (including poly isopropylene glycol).
[0037] A polyalkylene glycol (PAG), such as PEG, is a linear polymer terminated at each end with hydroxyl groups:
[0000] HO—CH 2 CH 2 O—(CH 2 CH 2 O) p —CH 2 CH 2 —OH.
[0038] The above polymer, α,ω-dihydroxyl poly(ethylene glycol), can also be represented as HO-PEG-OH, where it is understood that the -PEG- symbol represents the following structural unit:
[0000] —CH 2 CH 2 O—(CH 2 CH 2 O) p —CH 2 CH 2 —
[0000] where p may range from 0 to about 48. PEG may be used as methoxy-PEG-OH, or mPEG, in which one terminus is the relatively inert methoxy group, while the other terminus is a hydroxyl group that is subject to ready chemical modification. Additionally, random or block copolymers of different alkylene oxides (e.g., ethylene oxide and propylene oxide) that are closely related to PEG in their chemistry may be substituted for PEG.
[0039] The PAG polymers may be linear or branched.
[0040] It is to be understood that compounds of the invention comprise a PAG moiety that may include a mixture of polymers which have a varying number of monomeric units. The synthesis of a PAG-conjugate compound may produce a population of molecules with a Poisson distribution of the number of monomeric units per polymer in the conjugate. Thus, a compound according to the invention that is described as having a polymer of n=2 monomeric units refers not only to the actual polymers in that population being described as having n=2 monomeric units, but also to a population of molecules with the peak of the distribution being 2 or close to 2. The distribution of monomeric units in a given population can be determined, e.g., by nuclear magnetic resonance (NMR) or by mass spectrometry (MS).
[0041] In yet another aspect of the present invention there is provided a pharmaceutical composition for use in the treatment or prophylaxis of pain, said composition comprising a pharmaceutically effective amount of one or more of the compounds of the invention. Said composition may further comprise one or more pharmaceutically acceptable excipients. In some embodiments, said composition may also comprise acetaminophen, one or more other NSAIDs, one or more weak or strong opioids, an antidepressant or an antiepileptic agent.
[0042] The pharmaceutical composition of the invention may comprise one or more of the compounds of the invention in a pure, substantially pure or partially pure form. In some embodiments, said substantially pure form may comprise at least 95% wt. of said one or more compounds, e.g., 96% wt., 97% wt., 98% wt, or more than 99% wt. of said compounds.
[0043] Said substantially or partially pure form of said compound(s) may further comprise a proportion of free polyalkylene glycol such, for example, as polyethylene glycol (PEG) or polypropylene glycol (PPG). Such polyalkylene glycol may itself be biologically active. The chain length of the free polyalkylene glycol may range from 1-50, preferably 1-25, more preferably 1-5 or 1 or 2. In some embodiments, said polyalkylene glycol may have a chain length of 1, 2, 3 4 or 5 monomeric units. Said free polyalkylene glycol may comprise a mixture of different chain lengths. Thus, for a substantially pure form of said one or more compounds, said form may comprise up to 5% wt. of free polyalkylene glycol, e.g., up to 4% wt., 3% wt., 2% wt. or less than 1% wt., with the total amount in said form of said one or more compounds and said free polyalkylene glycol being 100% wt.
[0044] Said partially pure form of said one or more compounds may comprise about 5-60% wt of the one or more compounds according to the invention and about 95-40% wt. of free polyalkylene glycol, the total amount being 100% wt. Typically, said partially pure form may comprise about 45-55% wt. of said one or more compounds and about 55-45% wt. of said one or more polyalkylene glycols. Alternatively, said form may comprise about 80-95% wt. of said one or more compounds and about 20-5% wt. of said polyalkylene glycol(s).
[0045] Suitably, the composition of the invention may be formulated as a unit dosage form. Each unit dosage form may comprise all or a predetermined fraction of the daily dose amount of the one or more compounds of the invention, e.g., one half or one quarter of the daily dose amount.
[0046] Thus, the composition may be formulated as a tablet, a pill, a capsule, a powder, granules, a sterile parenteral solution or suspension, a metered aerosol or liquid spray, drops, an ampoule, an auto-injector device, a suppository, a cream or a gel. Said composition may be adapted for oral, enteral parenteral, intrathecal, intranasal, sublingual, rectal or topical administration, or for administration by inhalation or insufflation. Oral compositions such as tablets, pills, capsules or wafers are particularly preferred.
[0047] For preparing a solid dosage form such as a tablet, said one or more compounds may be mixed with one or more pharmaceutical excipients, e. g., conventional tabletting ingredients such as corn starch, lactose, sucrose, sorbitol, talc, stearic acid, magnesium stearate, dicalcium phosphate or gums, or other pharmaceutical diluents, e, g., water, to form a solid pre-formulation composition containing a substantially homogeneous mixture of said one or more compounds, such that said one or more compounds are dispersed evenly throughout the composition, so that the composition may be readily subdivided into equally effective unit dosage forms such as tablets, pills and capsules.
[0048] Said solid pre-formulation composition is then subdivided into unit dosage forms of the kind mentioned above which may each contain from 0.1 to about 500 mg of the one or more compounds. Favoured unit dosage forms contain from 1 to 500 mg, e.g., 1, 5, 10, 25, 50, 100, 300 or 500 mg, of the compound(s).
[0049] When formulated as a tablet or pill, said tablet or pill may be coated or otherwise compounded to provide a dosage form affording the advantage of prolonged action. For instance, said tablet or pill can comprise an inner dosage and an outer dosage component, the latter being in the form of an envelope over the former. These two components may be separated by an enteric layer that serves to resist disintegration in the stomach and permits the inner component to pass intact into the duodenum or to be delayed in release. A variety of materials are known in the use in such enteric layers or coatings, such materials including a number of polymeric acids and mixtures of polymeric acids with such materials as shellac, cetyl alcohol and cellulose acetate.
[0050] Alternatively, the pharmaceutical composition of the present invention may be formulated as a liquid dosage form for administration orally or by injection; for example an aqueous solution, a suitably flavoured syrup, an aqueous or oil suspension or a flavoured emulsion with edible oils such, for example, as cottonseed oil, sesame oil, coconut oil or peanut oil, as well as an elixir or a similar pharmaceutical vehicle. Suitable dispersing or suspending agents for an aqueous suspension include synthetic and natural gums, e.g., tragacanth, acacia, alginate, dextran, sodium carboxymethylcellulose, methylcellulose, polyvinyl-pyrrolidone or gelatin.
[0051] The following is a description by way of example only with reference to the accompanying drawings of embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 a provides graphs showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 or 3 of the invention;
[0053] FIG. 1 b provides graphs showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 or 3 of the invention;
[0054] FIG. 1 c provides graphs showing the results (weight of organs vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 or 3 of the invention;
[0055] FIG. 1 d provides a graph showing the results (time of reaction vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 or 3 of the invention;
[0056] FIG. 2 a provides graphs showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0057] FIG. 2 b provides graphs showing the results (total time vs, formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0058] FIGS. 3 a and 3 b provide graphs showing the results (time of reaction vs, time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0059] FIG. 3 c provides a graph showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0060] FIG. 4 a provides a graph showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0061] FIG. 4 b provides a graph showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0062] FIG. 5 a provides a graph showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 or 3 of the invention;
[0063] FIG. 5 b provides a graph showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 or 3 of the invention;
[0064] FIGS. 6 a , 6 b , and 6 c provide graphs showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0065] FIGS. 6 d and 6 e provide graphs showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 2 of the invention;
[0066] FIGS. 7 a , and 7 b provide graphs showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 1 of the invention;
[0067] FIGS. 7 c and 7 d provide graphs showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 1 of the invention;
[0068] FIG. 8 a provides a graph showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 3 of the invention;
[0069] FIG. 8 b provides a graph showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 3 of the invention;
[0070] FIGS. 9 a , and 9 b provide graphs showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 1 or 2 of the invention;
[0071] FIGS. 9 c , 9 d , 9 e provide graphs showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 1 or 2 of the invention;
[0072] FIGS. 10 a and 10 b provide graphs showing the results (time of reaction vs. time after treatment) of a Hot-Plate Test using Balb/c mice following administration of Compound 1 or 2 of the invention;
[0073] FIG. 10 c provides a graph showing the results (total time vs. formulation) of a Hot-Plate Test using Balb/c mice following administration of Compound 1 or 2 of the invention;
[0074] FIG. 11 provides a graph showing the results (increased volume vs. formulation of an edema test of SD rats following administration of Compound 2 or 3 of the invention;
[0075] FIGS. 12 a -12 e provide graphs showing the results (reaction vs. formulation) of a formalin test on Balb/c mice following administration of Compound 1 or 2 of the invention.
DETAILED DESCRIPTION
[0076] The present invention relates to methods for treating or preventing pain in a human or non-human animal patient in need thereof, which the method comprises administering to said patient a therapeutically effective amount of at least one compound represented by formula I:
[0000]
[0077] wherein:
[0078] represents a single or a double bond;
[0079] R 5 and R 5 ′ are independently —H, —OH or —OR 6 , wherein R 6 is a linear or branched C 1 -C 4 alkyl;
[0080] X is —CH 2 O—;
[0081] Z is —CH 2 CH 2 O—, —CH(CH 3 )CH 2 O— or —CH 2 CH(CH 3 )O—;
[0082] m is 1; and
[0083] n is an integer of 1, 2, 3, 4, or 5;
[0084] or a pharmaceutically acceptable salt, prodrug, metabolite, or hydrate thereof.
[0085] The present invention relates to a method for the treatment of acute or chronic pain. The present invention relates to a method for the treatment of nociceptive pain or neuropathic pain.
[0086] The present invention relates to a method for the treatment or prevention of pain, wherein the compound administered is represented by formula II:
[0000]
[0000] or a pharmaceutically acceptable salt prodrug, metabolite, or hydrate thereof. The present invention relates to a method, wherein Z is —CH 2 CH(CH 3 )O—.
[0087] The present invention relates to a method, wherein the compound administered is represented by formula III:
[0000]
[0000] or a pharmaceutically acceptable salt, prodrug, metabolite, or hydrate thereof.
[0088] The present invention relates to a method, wherein R 5 is H or OH. The present invention relates to a method, wherein R 5 ′ is H or OH. The present invention relates to a method, wherein n is 1 or 2.
[0089] The present invention relates to a method, wherein the compound is represented by formula IV, V, VI or VII:
[0000]
[0090] or a pharmaceutically acceptable salt, prodrug, metabolite, or hydrate thereof.
[0091] wherein R is a polyalkylene glycol polymer having n units, wherein n is an integer of 1, 2, 3, 4, or 5.
[0092] The present invention relates to a method, wherein the compound is administered as a pharmaceutical composition comprising a therapeutically effective amount of one or more of the compounds represented by formulae I, II, III, IV, V, VI, or VII together with one or more pharmaceutically acceptable excipients.
[0093] The present invention relates to a method, wherein the composition administered comprises said one or more compounds in substantially pure form, said substantially pure form consisting of at least 95% wt. of said one or more compounds and up to 5% wt. of free polyalkylene glycol, with the total amount in said form of said one or more compounds and said free polyalkylene glycol being 100% wt.
[0094] The present invention relates to a method, wherein the composition administered comprises said one or more compounds in partially pure form, said partially pure form consisting of about 5-60% wt. of the one or more compounds and about 95-40% wt. of free polyalkylene glycol, the total amount being 100% wt.
[0095] The present invention relates to a method, wherein the composition is formulated as a unit dosage form. The present invention relates to a method, wherein the composition is formulated for oral administration. The present invention relates to a method, wherein the composition is formulated as a unit dosage form comprising from 0.1 to about 500 mg of the one or more compounds. The present invention relates to a method, wherein a daily dose of 1.0 mg to 15 g of said one or more compounds is administered. The present invention relates to a method, wherein the one or more compounds are administered orally.
Synthesis of Polyalkylene Glycol Compounds
[0096] Polyalkylene glycol compounds were generally synthesised by preparation of the appropriate alcohol compound followed by conjugation of the alcohol with a polyalkylene glycol (PAG) polymer (e.g., polyethylene glycol (PEG) or polypropylene glycol (PPG)) of the desired length.
Synthesis a: Compound a (Phenyl Alaninol)
[0097] 1.2 g, 32 mM, of LiAlH 4 were added to 2.3 g, 10 mM, phenyl alanine ethyl ester HCl in 50 ml dry ether. After stirring for 2 hours at room temperature, water and KOH were added and the reaction product was extracted with ethyl acetate. After evaporation, 0.8 g of Compound a, a light yellow oil, was obtained.
[0000]
[0000] Compound a Crystallised on Standing. Mp-70.
[0098] NMR CDCl 3 7.30 (5H, m), 3.64 (1H, dd, J=10.5, 3.8 Hz) 3.40 (1H, dd, J=10.5, 7.2 Hz) 3.12 (1H, m), 2.81 (1H, dd, J=13.2, 5.2 Hz), 2.52 (1H, dd, J=13.2, 8.6 Hz)
[0099] NMR acetone d 6 7.30 (5H, m), 3.76 (1H, dt) 3.60 (1H, m) 3.30 (1H, t), 2.85 (2H, m). Helv. Chimn. Acta, 31, 1617(1948). Biels.—E3, Vol. 13, p 1757.
Synthesis b: Compound b (Tyrosinol)
[0100]
[0101] To 3 g, 12 mM, L-tyrosine ethyl ester.HCl in 50 ml dry ether was added 1.2 g 32 mM LiAlH 4 . After stirring 3 hours at room temperature, water and KOH were added and the reaction was extracted with ethyl acetate. Evaporation gave 1.1 g of a light yellow oil, 54% yield, which on standing crystallized. mp-85.
[0102] NMR CDCl 3 7.20 (4H, AB q, J=8.6 Hz), 3.50 (2H, m) 3.20 (1H, m), 2.81 (2H, m).
[0103] NMR tyrosine ethyl ester free base CDCl 3 7.0, 6.56 (4H, AB q, J=8.8 Hz), 4.20 (2H, q, J=7, 0 Hz), 3.70, 3.0, 2.80 (3H, 12 line ABXm), 1.28. (3H, t, J=7.0 Hz). JACS 71, 305(1949). Biels.—E3, Vol. 13, p 2263.
Synthesis 1: Compound 2
[0104]
[0105] Compound 2 (NRD135) has the structure of general formula IV, with R=PPG and n=1. MW=354
[0106] Compound 2 was synthesised as follows.
A)i)
[0107]
[0108] L-tyrosinol (24.4 g) was reacted with hydrocinnamic acid (HCA, 1.02 eq), DCC (1.1 eq), HOBT (1.1 eq) and NaHCO 3 (4.0 eq) at room temperature overnight. Reaction was completed overnight at RT. The reaction was filtered and a solvent swap from THF to EA was performed. The EA layer was washed with 1N HCl, sat NaHCO 3 , Brine, and organic layer dried over Na 2 SO 4 . Removal of a portion of EA was conducted via distillation, then slow addition of heptane afforded 33.82 g (94.1% yield) of desired product. HPLC: Purity=≧92%.
[0000] ii)
[0000]
[0109] The benzyl ether of AV74S was prepared. 1.33 eq benzyl chloride was charged to AV74S (50.90 g), 1.33 eq potassium carbonate, 0.1 eq potassium iodide in acetone at 50° C., After 20 hours at 50° C., the reaction was heated to reflux for an additional 7 hours to consume all the starting material. The reaction was cooled to room temperature and quenched with water. The slurry was cooled to <5° C. and stirred for 1.5 hours, then filtered. The solids were dried in vacuo (70° C.) over the weekend to afford 62.98 g of crude solids. The AUC purity was 94.4%. 1 H NMR analysis supports the assigned structure.
B)i)
[0110]
[0111] A 5-fold excess of propylene glycol was treated with trityl-Cl (246.7 g, 885 mmol) in the presence of pyridine and DMAP in DMF at rt. The reaction was allowed to stir over the weekend at rt. The mixture was diluted with 3 vol of water and extracted with EA. The recrystallization from acetonitrile/water afforded 235.04 g (83.4% yield, Purity=98.7%) of desired product.
[0000] ii)
[0000]
[0112] The trityl ether (99.82 g, 313.5 mmol) was converted into the orthogonaly protected bis ether. To a <10° C. slurry of 2 equiv of NaH in DMF was added dropwise trityl ether at a rate to control gas evolution. After stirring for 15 minutes at <10° C., p-methoxybenzyl chloride was added via syringe. The mixture was warmed to rt (mildly exothermic) and allowed to stir at rt for 1.5 hours. HPLC analysis indicated complete consumption of starting material. Workup consisted of careful quenching of the mixture with 3 volumes of water and EA extraction. The EA layers were washed with water to remove DMF and dried over Na 2 SO 4 to give a hazy oil (150.95 g,).
[0000] iii)
[0000]
[0113] The protected bis ether was exposed to a catalytic amount of para-toluenesulfonic acid to detritylate the trityl group. To the protected bis ether (150.95 g, PR030-084-2) in methanol and THF was added a catalytic amount (0.1 eq) of para-toluenesulfonic acid. After 60 minutes at room temperature, thin layer chromatography and HPLC analysis indicated that the reaction was complete, Triethylamine was added to quench the reaction and the solvent was removed via DURP, The desired product was isolated from a silica gel plug to afford 51.74 g (84% yield, Purity=98.4%). 1 H NMR analysis supported the assigned structure.
[0000] iv)
[0000]
[0114] The mesylation of PPG-1-Hydroxy-2-OPMB (20.1 g) was conducted using 2.0 eq of methanesulfonyl chloride and 2.25 eq of triethylamine at <5° C. to give a clean conversion to desired product in 108% crude yield as an oil. This material was sufficiently pure to use for next steps.
C)i)
[0115]
[0116] 20.13 g OBn-Tyrosinol core (from step A) and 2.25 eq PPG-1-OMesyl-2-OPMB (from step B) in DMSO was added 2.0 eq of 1M potassium tert-butoxide (in THF) over 1.6 hours at room temperature. After 15.5 hours at room temperature, 91.9% of desired product had formed and 8.1% of OBn-Tyrosinol core was not fully consumed. An additional 0.3 eq of 1M potassium tert-butoxide was added and the reaction was allowed to stir at 45° C. After an additional 18 hours at 45° C., 98.3% of desired product had formed and 1.7% of OBn-Tyrosinol core was not fully consumed. The reaction mixture was quenched with USP water at room temperature and extracted with ethyl acetate. The combined organic layers were successively washed with USP water, saturated aqueous NaHCO3 solution, brine, and dried over sodium sulfate to afford 39.00 g of an oil. An attempt to recrystallize from toluene/heptane proved to be unsuccessful and provided 25.8 g of solids that were 77.4% pure of desired product.
[0117] Celite was added to 25.3 grams of PR030-114-12 dissolved in hot MTBE/Heptane (1:1). This mixture was filtered hot over a bed of Celite. The filtrate was cooled to room temperature and the solids were collected via vacuum filtration to provide 13.1 g of white solids (52.4% yield). A second crop was obtained giving an additional 2.75 g of white solids (an additional 11% yield). The purity of these two crops was 98.8% and 98.1%, respectively. 1H NMR and Mass spec analysis supported the assigned structure for desired product. The combined yield was 63.5%.
[0000] iii)
[0000]
[0118] The bis-protected ether (15.7 g) was exposed to one-pot hydrogenation-debenzylation conditions (10% loading of 10% Pd/C and 0.25 eq ofp-toluenesulfonic acid) in methanol. After 2 hours at 60° C. under a hydrogen atmosphere, HPLC analysis indicated that the hydrogenation of the benzyl and the debenzylation of PMB ring was complete. The reaction mixture was filtered over Celite and concentrated under reduced pressure. The residue was dissolve in ethyl acetate and a saturated aqueous sodium bicarbonate treatment was conducted to effectively remove p-toluenesulfonic acid, then DURP to provide 12.13 g of an oil (PR030-120-4). Desired product was isolated from an EA/Heptane recrystallization to provide 8.83 g of a white solid (PR030-120-6, 89.4% yield). The purity of PR030-120-6 was 99.3% via HPLC analysis. 1H NMR and Mass spec analysis supported the assigned structure for desired product.
Synthesis 2: Compound 1
[0119]
[0120] Compound 1 has the structure of general formula IV, with R=PPG and n=2. MW 413 Compound 1 was prepared using the same procedure as described above in Synthesis 1, with the substitution of the PPG, n=1 for PPG, n=2.
[0121] It will be understood that the procedures of Synthesis 1 can therefore be applied to produce compounds of formula VII in which Z is PPG. Alternative compounds falling within formula I can be produced by substitution of L-tyrosinol in step (A) with the appropriate amino alcohol (e.g. phenyl alaninol as produced in synthesis a)).
[0122] The procedures of Synthesis 1 can also be adapted as described below in Synthesis 3 so that they result in the production of a compound of formula 1 in which Z is PEG.
Synthesis 3: Compound 3
[0123]
[0124] Compound 3 has the structure of general formula IV, with R=PEG and n=1. MW=413 Compound 3 was prepared using the following procedure.
[0000] A) Step A was performed as for compound 2.
B)i)
[0125]
[0126] A 5-fold excess of ethylene glycol was treated with trityl-Cl (22.9 g, 82.13 mmol) in the presence of pyridine and DMAP in DMF at rt. The reaction was allowed to stir overnight at room temperature. The mixture was diluted with 3 vol of water and extracted with EA. Isolation of desired product via recrystallization from acetonitrile/water gave 22.87 g of solids (91.5% yield), The purity determined by HPLC was 97.8%. 1H NMR and Mass Spec analysis supported the assigned structure for desired product.
[0000] ii)
[0000]
[0127] The mesylation of compound A-1 (11.00 g) was conducted using 2.0 eq of methanesulfonyl chloride and 2.25 eq of triethylamine at <5° C. to give a clean conversion to desired product in quantitative yield as a solid (13.85 g). AUC purity=97.5%, Mass spec and 1 H NMR analysis supported the assigned structure.
[0000] C)i) 2.29 g of OBn-Tyrosinol core (from step A) and 2.25 eq of Compound B-1 (from Step B) in DMSO was added 2.0 eq of 1M potassium tert-butoxide (in THF) over 45 mins at room temperature. After 12.25 hours at 35° C., the reaction mixture was quenched with USP water at room temperature and extracted with ethyl acetate. The combined organic layers were successively washed with USP water, saturated aqueous NaHCO 3 solution, brine, and dried over sodium sulfate to afford 5.05 g as an oil. This product was purified via column chromatography to isolate the desired product as a solid (2.07 g). AUC purity=97.5%. 1 H NMR analysis supported the assigned structure for desired product.
ii)
[0000]
[0128] 2.07 g C-1, C-1 was dissolved in 30 vol methanol at 60 C. 10 wt % Pd/C then 0.25 eq pTSA was added while at 60 C. Hydrogen atmosphere was maintained for 3 hours. The catalyst was removed by hot filtration. The filtrate was DURP to obtain a solid. The solids were dissolved in ethyl acetate and washed with sodium bicarbonate. The organic was dried over sodium sulfate and DURP to give gooey solids.
EXAMPLES
[0129] The experiments described below were conducted to demonstrate the utility of compounds of the invention in the treatment of pain.
Example 1
Antinociceptive Effect of Compound 2 and Compound 3
[0130] The objective of the study was to assess antinociceptive activity of tested items in the hot plate tests in mice, when administered sub-chronically. Measuring paw licking or jumping response time elapses following placement on heated surface (hot plate) was used to determine potential antinociceptive effect in mice.
[0131] A total of 42 Balb/c mice (12 weeks old) were utilized. The mice were approximately 25 g males at study initiation. The minimum and maximum weights of the group were within a range of ±10% of group mean weight.
[0132] Compounds 2 and 3 were tested and compared with Diclofenac® (Perigo). DMSO solutions were used. Six groups of mice (each having n=7 or n=8 mice) were tested, the last group receiving Diclofenac®.
[0000]
Testing at:
Dose
Animal group
Dose volume
Time/min
mg/kg/day
1M (sham) (7)
10 ml/kg
−60, 0, 60, 120, 180,
None
DMSO
240, 300, 360
2M + 3M (7 + 7)
0.1; 5
compound 2 [1 unit]
4M + 5M (7 + 7)
0.1; 5
Compound 3 [1 unit]
6M (8)
10
Diclofenac ®
[0133] Formulations according to the following table were prepared for administration to the groups of mice.
[0000]
Formulation
Composition
1
Control - 0.02% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (0.6 μl DMSO + 2999.4 μl
DDW), n = 8.
2
Compound 2, 0.1 mg/Kg = 0.003 mg/0.3 ml/mouse, po (3 ml/10 mice) (compound 2,
0.03 mg (Stock 50 mg/1 ml DMSO) 0.6 μl + 2999.4 μl DDW), n = 8
3
Compound 2, 5 mg/Kg = 0.15 mg/0.3 ml/mouse, po (3 ml/10 mice) (compound 2 1.5 mg
(Stock 50 mg/1 ml DMSO) 30 μl + 2970 μl DDW), n = 8
4
Compound 3, 0.1 mg/kg = 0.003 mg/0.3 ml/mouse, po (3 ml/10 mice) (compound 3,
0.03 mg (Stock 50 mg/1 ml DMSO) 0.6 μl + 2999.4 μl DDW), n = 8
5
Compound 3, 5 mg/Kg = 0.15 mg/0.3 ml/mouse, po (3 ml/10 mice) (compound 3 1.5 mg
(Stock 50 mg/1 ml DMSO) 30 μl + 2970 μl DDW), n = 8
6
Diclofenac ® 10 mg/kg = 0.3 mg/0.3 ml/mouse, po (3 ml/10 mice) from stock
(Diclofenac ® 51 mg + 51000 μl DDW), n = 8
[0134] All groups received the drugs daily po for 16 days. Hot plate experiments were performed on days; 1, 8 and 15.
[0135] The following parameters were examined: body weight (days 1, 8 15); open field on day 16 including distance moved, velocity, immobility, rearings, time in center and other parameters. After the last experiment (i.e., open field day 16), animals were sacrificed by decapitation and blood was collected 24 hr after last drug administration. The following organs were dissected: liver (gall bladder), spleen, lungs, brain, heart and kidney for toxicity examination (formaldehyde 4%).
[0136] The hot plate is maintained thermostatically at a temperature of 52° C. One hour before the administration of the drugs, mice are tested in the hot plate. At time 0 the mice are administered with the test compound and the response to the hot plate is measured again at different times: 60, 120, 180, 240, 300 and 360 min.
[0137] Results are expressed as: Delta from maximum response [baseline vs. maximum response]; Absolute measures over time; and Accumulated time.
[0138] FIGS. 1 a and 1 b provide graphical results showing a comparison of compounds 2 and 3 with Diclofenac® at days 1, 8, and 15.
[0139] FIG. 1 c shows internal organ weight data after administration of the tests.
[0140] Additional data showed that compositions 2-5 significantly increased the time to reaction as compared with the control. A sample of such data is provided in FIG. 1 d.
[0141] These data show that compounds 2 anid 3 are effective as pain relievers.
Example 2
Nociceptin Activity Using Compound 2
[0142] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 9 weeks old, naïve), were divided in 5 groups (8 mice per group) and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - 0.2% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (6 μl DMSO + 2994 μl
DDW), n = 8.
2
Compound 2, 0.01 mg/Kg = 0.0003 mg/0.3 ml/mouse, po (3 ml/10 mice)
(Compound 2, 0.003 mg (Stock 50 mg/1 ml DMSO) 0.06 μl + 2999.94 μl
DDW), n = 8
3
Compound 2, 0.1 mg/Kg = 0.003 mg/0.3 ml/mouse, po (3 ml/10 mice)
(Compound 2, 0.03 mg(Stock 50 mg/1 ml DMSO) 0.6 μl + 2999.4 μl
DDW), n = 8
4
Compound 2, 1 mg/kg = 0.03 mg/0.3 ml/mouse, po (3 ml/10 mice) (Compound
2, 0.3 mg (Stock 50 mg/1 ml DMSO) 6 μl + 2994 μl DDW), n = 8
5
Compound 2, 0.1 mg/Kg = 0.003 mg/0.3 ml/mouse, i.p, (3 ml/10 mice)
(Compound 2, 0.03 mg (Stock 50 mg/1 ml DMSO) 0.6 μl + 2999.4 μl DDW),
n = 8
[0143] The animals were determined on the hotplate at: −60, 0, 120, 240, 360, 420 and 480 min. The hotplate mean temperature was 52 degrees±1.
[0144] FIGS. 2 a and 2 b provide data for these tests.
Example 3
Nociceptin Activity Using Compound 2
[0145] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 9 weeks old, naïve), were divided in 5 groups (8 mice per group) and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 2.5% DMSO 0.25 ml/mouse, po (2.5 ml/10 mice) (63 μl DMSO +
2437 μl DDW), n = 8.
2
Compound 2, eqM 25 (12.5)mg/Kg = 0.3125 mg/0.25 ml/mouse, po (2.5 ml/10
mice) ((Compound 2 3.125 mg (Stock 50 mg/1 ml DMSO) 63 μl + 2437 μl DDW)
3
Compound 2 eqM 12.5 (6.25)mg/Kg = 0.15625 mg/0.25 ml/mouse, po (2.5 ml/10
mice) ((Compound 2 1.5625 mg (Stock 50 mg/1 ml DMSO) 32 μl + 2468 μl DDW)
4
Compound 2 eqM 6.25 (3.125)mg/Kg = 0.078 mg/0.25 ml/mouse, po (2.5 ml/10
mice) ((Compound 2 0.78 mg (Stock 50 mg/1 ml DMSO) 16 μl + 2484 μl DDW)
[0146] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 min. The hot-plate means the temperature of 52 degrees±1.
[0147] FIGS. 3 a , 3 b , and 3 c provide data for this test.
Example 4
Nociceptin Activity Using Compound 2
[0148] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 13 weeks old, not naïve), were divided in 5 groups (8 mice per group) and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 0.2% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (6 μl DMSO +
2994 μl DDW), n = 8.
2
Compound 2 (Mw 357) 1 mg/Kg = 0.03 mg/0.3 ml/mouse, po (3 ml/10 mice)
((Compound 2 0.3 mg (Stock 50 mg/1 ml DMSO) 6 μl + 2994 μl DDW)
3
Compound 2 (Mw 357) 0.2 mg/Kg = 0.006 mg/0.3 ml/mouse, po (3 ml/10 mice)
((Compound 2 0.06 mg (Stock 50 mg/1 ml DMSO) 1.2 μl + 2998.8 μl DDW)
4
Compound 2 (Mw 357) 0.04 mg/Kg = 0.0012 mg/0.3 ml/mouse, po (3 ml/10 mice)
((Compound 2 0.012 mg (Stock 50 mg/1 ml DMSO) 0.24 μl + 2999.76 μl DDW)
5
Compound 2 (Mw 357) 0.008 mg/Kg = 0.00024 mg/0.3 ml/mouse, po (3 ml/10
mice) ((Compound 2 0.0024 mg (Stock 50 mg/1 ml DMSO) 0.048(0.05) μl +
2999.95 μl DDW)
[0149] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 min after treatment. The hot-plate means the temperature of 52 degrees±1.
[0150] FIGS. 4 a and 4 b provide data for this test.
Example 5
Nociceptin Activity Using Compound 2 and 3
[0151] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 15 weeks old, not naïve), were divided in 5 groups (8 mice per group) and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 0.02% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (0.06 μl
DMSO + 2999.94 μl DDW), n = 8.
2
Compound 2 (MW = 357) 0.01 mg/Kg = 0.0003 mg/0.3 ml/mouse, po (3 ml/10
mice) (Compound 2 0.003 mg (Stock 50 mg/1000 μl DMSO) 0.06 μl + 2999.94 μl
DDW), n = 8
3
Compound 2 0.001 mg/Kg = 0.00003 mg/0.3 ml/mouse, po (3 ml/10 mice)
(Compound 2 0.0003 mg (Stock 50 mg/1000 μl DMSO) 0.006 μl + 2999.994 μl
DDW), n = 8
4
Compound 3 (MW = 343) 0.01 mg/Kg = 0.0003 mg/0.3 ml/mouse, po (3 ml/10
mice)(Compound 3 0.003 mg (Stock 50 mg/1000 μl DMSO) 0.06 μl + 2999.94 μl
DDW), n = 8
5
Compound 3 0.001 mg/Kg = 0.00003 mg/0.3 ml/mouse, po (3 ml/10 mice)
(Compound 3 0.0003 mg (Stock 50 mg/1000 μl DMSO) 0.006 μl + 2999.994 μl
DDW), n = 8
[0152] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 mil after treatment. The hot-plate means the temperature of 52 degrees±1.
[0153] FIGS. 5 a and 5 b provide data for this experiment.
Example 6
Nociceptin Activity Using Compound 2
[0154] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 9 weeks old, not naïve), were divided in 5 groups (8 mice per group) and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 1.24% DMSO 0.25 ml/mouse, po (2.5 ml/10 mice) (31 μl
DMSO + 2469 μl DDW), n = 8,
2
Compound 2 (Mw 357) 6.25 mg/Kg = 0.15625 mg/0.25 ml/mouse, po (2.5 ml/10
mice) ((Compound 2 1.5625 mg (Stock 50 mg/1 ml DMSO) 31.25 (31) μl + 2469 μl
DDW)
3
Compound 2 (Mw 357) 2.083 (2.1) mg/Kg = 0.052 mg/0.25 ml/mouse, po (2.5 ml/
10 mice) ((Compound 2 0.52 mg (Stock 50 mg/1 ml DMSO) 10.415 (10) μl +
2490 μl DDW)
4
Compound 2 (Mw 357) 0.694 (0.7) mg/Kg = 0.01735 mg/0.25 ml/mouse, po (2.5 ml/
10 mice) ((Compound 2 0.1735 mg (Stock 50 mg/1 ml DMSO) 3.47(3) μl +
2497 μl DDW)
5
Gabapentine (GBP) 30 mg/Kg = 7.5 mg/0.25 ml/mouse, po (2.5 ml/10 mice) (GBP
7.5 mg + 2500 μl DDW)
[0155] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 min, and 24 h after treatment. The hot-plate means the temperature of 52 degrees±1
[0156] FIGS. 6 a - e provide the data from this test.
Example 7
Nociceptin Activity Using Compound 1
[0157] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 12 weeks old, naïve), were divided in 5 groups (8 mice per group) and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 5% DMSO 0.25 ml/mouse, po (2.5 ml/10 mice) (125 μl DMSO +
2375 μl DDW), n = 8.
2
Compound 1 25 mg/Kg = 0.625 mg/0.25 ml/mouse, po (2.5 ml/10 mice)
(Compound 1 1.5625 mg (Stock 30 mg/0.6 ml DMSO) 32 μl + 2468 μl DDW)
3
Compound 1 (Mw 415) eqM 25 mg/Kg (15 mg/kg) = 3.75 mg/0.25 ml/mouse, po
(2.5 ml/10 mice)(Compound 1 3.75 mg (Stock 30 mg/0.6 ml DMSO) 75 μl +
2425 μl DDW)
4
Compound 1 (Mw 415) eqM 12.5 mg/Kg (7.5 mg/kg) = 1.875 mg/0.25 ml/mouse,
po (2.5 ml/10 mice)(Compound 1 1.875 mg (Stock 30 mg/0.6 ml DMSO) 37.5 (38)
μl + 2462 μl DDW)
[0158] The animals were determined on HP at; −60, 0, 60, 120, 180, 240, 300 and 360 min, and 24 h. The hot-plate means the temperature of 52 degrees±1.
[0159] FIGS. 7 a - d provide data for this experiment.
Example 8
Nociceptin Activity Using Compound 3
[0160] Using the procedure outlined in Example 1, 37 male mice (Balb/c, 16 weeks old, not naïve), were divided in 5 groups and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 1.2% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (36 μl DMSO +
2964 μl DDW), n = 7.
2
Compound 3 (MW = 343) 0.06 mg/Kg = 0.0018 mg/0.3 ml/mouse, po (3 ml/10
mice) (Compound 3 0.018 mg (Stock 4.6 mg/92 μl DMSO) 0.36 μl + 2999.64 μl
DDW) n = 7
3
Compound 3 0.6 mg/Kg = 0.018 mg/0.3 ml/mouse, po (3 ml/10 mice) (Compound
3 0.18 mg (Stock 4.6 mg/92 μl DMSO) 3.6 μl + 2996.4 μl DDW), n = 7
4
Compound 3 6 mg/Kg = 0.18 mg/0.3 ml/mouse, po (3 ml/10 mice) (Compound 3
1.8 mg (Stock 4.6 mg/92 μl DMSO) 36 μl + 2964 μl DDW), n = 8
5
Diclofenac 50 mg/Kg = 1.25 mg/0.3 ml/mouse, po (3 ml/10 mice) Diclofenac 14.4 mg +
0.25 μl DMSO + 2999.75 μl DDW), n = 8
[0161] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 min after treatment. The hot-plate means the temperature of 52 degrees±1.
[0162] FIGS. 8 a and 8 b provide data for this experiment.
Example 9
Nociceptin Activity Using Compounds 1 and 2
[0163] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 13 weeks old, not naïve), were divided in 5 groups and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 0.8% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (24 μl DMSO +
2976 μl DDW), n = 8.
2
Compound 2 (Mw 357) 4 mg/Kg = 0.12 mg/0.3 ml/mouse, po (3 ml/10 mice)
((Compound 2 1.2 mg (Stock 50 mg/1 ml DMSO) 24 μl + 2976 μl DDW)
3
Compound 2 (Mw 357) 0.04 mg/Kg = 0.0012 mg/0.3 ml/mouse, po (3 ml/10 mice)
((Compound 2 0.012 mg (Stock 50 mg/1 ml DMSO) 0.24 μl + 2999.76 μl DDW)
4
Compound 1 (Mw 415) eq.4 (4.65)mg/Kg = 0.14 mg/0.3 ml/mouse, po (3 ml/10
mice) ((Compound 1 1.395 mg (Stock 30 mg/0.6 ml DMSO) 27.9(28) μl + 2972 μl
DDW)
5
Compound 1 (Mw 415) eq. 0.04 (0.05)mg/Kg = 0.0014 mg/0.3 ml/mouse, po (3 ml/
10 mice) ((Compound 1 0.014 mg (Stock 60 mg/0.6 ml DMSO) 0.279 (0.28) μl +
2999.72 μl DDW)
[0164] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 min after treatment. The hot-plate means the temperature of 52 degrees±1,
[0165] FIGS. 9 a - e provide data for this experiment.
Example 10
Nociceptin Activity Using Compounds 1 and 2
[0166] Using the procedure outlined in Example 1, 40 male mice (Balb/c, 13 weeks old, not naïve), were divided in 5 groups and treated daily (0 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 0.04% DMSO 0.3 ml/mouse, po (3 ml/10 mice) (1.2 μl DMSO +
2998.8 μl DDW), n = 8.
2
Compound 1 0.125 mg/Kg = 0.00375 mg/0.3 ml/mouse, po (3 ml/10 mice)
(Compound 1 0.0375 mg (Stock 60 mg/1.2 ml DMSO) 0.75 μl + 2999.25 μl DDW),
n = 8
3
Compound 2 0.1 mg/Kg = 0.003 mg/0.3 ml/mouse, po (3 ml/10 mice) (Compound
2 0.03 mg (Stock 60 mg/1.2 ml DMSO) 0.6 μl + 2999.4 μl DDW), n = 8
4
Diclofenac 50 mg/Kg = 1.25 mg/0.3 ml/mouse, po (3 ml/10 mice) Diclofenac 12.5 mg +
0.25 μl DMSO + 2999.75 μl DDW), n = 8
[0167] The animals were determined on HP at: −60, 0, 60, 120, 180, 240, 300 and 360 min after treatment. The hot-plate means the temperature of 52 degrees±1.
[0168] FIGS. 10 a , 10 b , and 10 c provide data for this experiment.
Example 11
Edema Test
[0169] Male SD rats (9 weeks old, naïve), were divided into 5 groups (6 mice in each group) and treated (−120 min, p.o.) with the formulations shown in the following table.
[0000]
Formulation
Composition
1
Control - DDW + 10% DMSO 0.3 ml/rat, po (2.4 ml/8 rats) (241 μl DMSO +
2159 μl DDW)
2
Compound 2, 1 mg/Kg = 0.3 mg/0.3 ml/rat, po (2.4 ml/8 rats) (Compound 2,
2.4 (Stock 21.5 mg/0.43 ml DMSO) 32 μl + 2352 μl DDW)
3
Compound 2, 5 mg/Kg = 1.5 mg/0.3 ml/rat, po (2.4 ml/8 rats) (Compound 2,
12 mg (Stock 21.5 mg/0.43 ml DMSO 241 μl + 2159 μl DDW)
4
Compound 3 1 mg/Kg = 0.3 mg/0.3 ml/rat, po (2.4 ml/8 rats) (Compound 3 2.4 mg
(Stock 19.1 mg/0.382 ml DMSO) 32 μl + 2352 μl DDW)
5
Compound 3 5 mg/Kg = 1.5 mg/0.3 ml/rat, po (2.4 ml/8 rats) (Compound 3, 12 mg
(Stock 19.1 mg/0.382 ml DMSO) 241 μl + 2159 μl DDW)
[0170] FIG. 11 provides data from this test.
Example 12
Formalin Test
[0171] Formalin test. The method used was similar to that described by Hunscaar and Hole (1987) “The formalin test in mice: dissociation between inflammatory and non-inflammatory pain,” Pain 30, pp. 103-104.
[0172] Five animals are used in each group and two to three hours after oral administration of the conjugates, 40 μl or 20 μl (rats or mice, respectively) of a 1% formalin (in 0.9% saline) solution is injected subcutaneously into the dorsal surface hind paw. The formalin induced typical flinching behaviour of the injected paw which was counted. The animals were returned to a glass chamber and the total time spent by the animal licking or biting the injected paw was measured, Formalin induced pain behaviour is biphasic. The duration of paw licking was determined during the following two time periods: 0-5 min (first-neurogenic phase) and 20-30 min (second-inflammatory phase) after formalin injection.
[0173] Part a. Male mice (Balb/c mice, 27 weeks old, not naïve), were divided in 4 groups (5 mice per group) and treated (0 min, i.p.) with the following formulations, respectively:
[0000]
Formulation
Composition
1a
Control - (0.2 ml DMSO + 3.52 saline) i,p, 0.3 ml/mouse. n = 5.
2a
Compound 2, 0.2 mg/kg = 0.006 mg/0.3 ml/mouse, 6 mice/0.036 mg/1.8 ml =
(0.72 μl (2 mg compound 2 + 40 μl DMSO) + 1799.28 μl DDW) n = 5.
3a
Compound 2, 1 mg/kg = 0.03 mg/0.3 ml/mouse, 6 mice/0.18 mg/1.8 ml = (3.6 μl
(2 mg compound 2 + 40 μl DMSO) + 1796.4 μl DDW) n = 5.
4a
Compound 2, 2.5 mg/kg = 0.15 mg/0.3 ml/mouse, 6 mice/0.9 mg/1.8 ml = (9 μl
(2 mg stock compound 2 + 40 μl DMSO) + 1782 μl DDW) n = 5.
[0174] Part b. Male mice (Balb/c mice, 27 wee s old, no naïve), were divided in groups (5 mice in groups) and treated (0 min, i.p.) with the following formulations, respectively:
[0000]
Formulation
Composition
1b
Control - (0.2 ml DMSO + 3.52 saline) i,p. 0.3 ml/mouse. n = 5.
2b
Compound 2 0.2 mg/kg = 0.006 mg/0.3 ml/mouse, 6 mice/0.036 mg/1.8 ml =
(0.72 μl (1.3 mg compound 2 + 26 μl DMSO) + 1799.28 μl DDW) n = 5.
3b
Compound 2 1 mg/kg = 0.03 mg/0.3 ml/mouse, 6 mice/0.18 mg/1.8 ml = (3.6 μl
(1.3 mg compound 2 + 26 μl DMSO) + 1796.4 μl DDW) n = 5.
4b
Compound 2 2.5 mg/kg = 0.15 mg/0.3 ml/mouse, 6 mice/0.9 mg/1.8 ml = (9 μl
(1.3 mg compound 2 + 26 μl DMSO) + 1782 μl DDW) n = 5.
[0000]
TABLE 1a
Data from Part a.
Formalin 1% (50 μl) intraplantar route in the right hind paw
(3 h after the treatment)
# mouse
weight
treatment
Formalin
5 min
inflam.
10 min
1
08:20
11:20
11:40
2
08:30
11:30
11:50
3
08:40
11:40
12:00
4
08:50
11:50
12:10
5
09:00
12:00
12:20
6
09:10
12:10
12:30
7
09:20
12:20
12:40
8
09:30
12:30
12:50
9
09:40
12:40
13:00
10
09:50
12:50
13:10
11
10:50
13:50
14:10
12
11:00
14:00
14:20
13
11:10
14:10
14:30
14
11:20
14:20
14:40
15
11:30
14:30
14:50
16
11:40
14:40
15:00
17
11:50
14:50
15:10
18
12:00
15:00
15:20
19
12:10
15:10
15:30
20
12:20
15:20
15:40
[0000]
TABLE 1b
Data from Part b.
Formalin 1% (50 μl) intraplantar route in the right hind paw
(4 h after the treatment)
# mouse
weight
treatment
Formalin
5 min
inflam.
10 min
1
06:30
10:30
10:50
2
06:40
10:40
11:00
3
06:50
10:50
11:10
4
07:00
11:00
11:20
5
07:10
11:10
11:30
6
07:20
11:20
11:40
7
07:30
11:30
11:50
8
07:40
11:40
12:00
9
07:50
11:50
12:10
10
08:00
12:00
12:20
11
08:10
12:10
12:30
12
08:20
12:20
12:40
13
08:30
12:30
12:50
14
08:40
12:40
13:00
15
08:50
12:50
13:10
16
09:00
13:00
13:20
17
09:10
13:10
13:30
18
09:20
13:20
13:40
19
09:30
13:30
13:50
20
09:40
13:40
14:00
[0175] Results from these tests are plotted in FIGS. 12 a and 12 b respectively. FIGS. 12 c , 12 d , and 12 e provide further data based on measurement time. These data further confirm the anti-inflammatory properties of Compound 2.
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Compounds for use in the treatment or prophylaxis of pain, including acute and chronic pain (e.g., nociceptive pain, neuropathic pain, headaches, migraine), represented by general formula I:
in which:
the dotted line represents a single or a double bond; and R 5 and R 5 ′ are independently —H, —OH or —OR 6 , where R 6 is a linear or branched C 1 -C 4 alkyl; X is —CH 2 O—; Z is —CH 2 CH 2 O—, —CH(CH 3 )CH 2 O— or —CH 2 CH(CH 3 )O—; m is 1; and n is an integer of 1-5. The compounds of the invention are also effective for reducing inflammation and may be used alone or in combination with other analgesics.
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FIELD OF TECHNOLOGY
The present disclosure relates to subsea well intervention, in particular, a device for multi-purpose well intervention disposed on a vessel, wherein the well intervention device has the advantage of safer and quicker transfer between several modes of operation, such modes of operations can be categorized as on-axis activities and off-axis activities.
BACKGROUND
There are different classes of offshore installations. For example, mobile offshore drilling units, floating platforms, fixed platforms, and tension legs. Each of these installations has their own applications and drawbacks.
Mobile offshore drilling units (MODU) are more susceptible, than other types of offshore structures to meteorological conditions such as winds, currents and, most importantly, waves. These meteorological conditions generate movement of the MODU that will inevitably be transferred to some extent to the drilling pipe, which is fixedly connected to the wellhead located in a fix spot on the seabed. When the drilling pipe is connected to the wellhead (e.g., for well intervention or drilling), the MODU utilizes a passive heave compensation system. When there is no drilling pipe connected (e.g., open sea drilling), the MODU utilizes an active heave compensation system.
Several motion intervention devices are known, for example, the use of motion intervention frames is a widely known technique in coiled tubing drilling activities. Therein the coiled tubing injector is attached to a frame that, generally, through the use of winches, is hung to a fixed structure; the winches are pneumatically or hydraulically controlled to follow the injector and thereby compensate for the relative movement between the injector and the pipeline to which the injector acts on. U.S. Patent Publication US20140308105A1 teaches an example of such motion intervention devices.
Prior art devices acknowledge the presence of meteorological conditions that modify the position of pipelines that are connected to the seafloor with respect to the vessel (and, therefore, of every intervention device located on such vessel) and have developed different kinds of frames to minimize the effects of the dynamic loads of the intervention devices and their movement with respect to the pipeline. Such compensating action is always performed on the intervention devices themselves (e.g., by hanging the intervention device to a constant-tension winch or by modifying the position of the intervention devices in view of the load of a wellhead so that it does not exceed a determined threshold value).
One of the major problems with the prior art systems is that during coiled tubing drilling a coiled tubing lifting frame (CTLF) is normally used. The CTLF is a massive structure that needs to be handled in an unmounted way and that is mounted below the derrick (i.e., it is normally too large to be mounted outside the derrick). The CTLF is subsequently hung from the top of the derrick and the injector is attached on the CTLF. When operations are to be performed on a pipeline (e.g. wireline operations for inspecting or maintaining the pipeline) the injector has to be lowered back to the vessel and the CTLF removed for safety reasons (i.e., it is unsafe to keep workers under a hanging structure). The operation process normally takes a long time (e.g., 4-6 hours) and can slow down and make drilling operations more expensive.
Another problem of prior art systems is taking measurements during well intervention operations. Specifically, switching between coiled tubing and wireline operations is a time consuming process. In traditional systems using a CTLF (as illustrated above) it can take 4-6 hours to remove the injector and configure wireline. The time spent changing configurations can add to the cost of the intervention operation.
Another problem of prior art systems is that operations to be performed on the drill riser (i.e., while the injector is attached to the pipeline) are typically performed by a man-rider or harnessed worker (e.g., by crane). Thus, it can be difficult to perform complex operations or to perform work between several people. Furthermore, if work is to be performed on the injector is has to be lowered to the deck of the vessel. In both of these cases, the use of prior art techniques result in a timely and risky operation.
Another problem encountered with the prior art systems, is the complexity of changing from a coiled tubing drilling to a joint-pipe drilling configuration. (e.g, to change from an injector to a top-drive). In prior art systems, the intervention frame must be reconfigured to a new weight and the injector has to be disengaged from the conduit and removed to a platform (i.e., on the vessel). The movement of such a heavy device is unsecured and the vessel is subject to movements that can damage the device. Furthermore, the change between modes requires a considerable amount of time.
SUMMARY
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims, or can be learned by the practice of the principles set forth herein.
The present disclosure solves the above-mentioned problems by modifying the approach of movement intervention for different modes of operations as described below. The MODU has two modes of operation: well intervention mode and drilling mode. In well intervention mode a conduit can be attached to a rooster box. The conduit can be maintained at a determined upright tension that can be monitored by the rooster box. In drilling mode, the rooster box can push down the conduit and the downward force from the rooster box (i.e., compressive force) can to be monitored (e.g., by the rooster box).
Also, in some drilling mode operations, the rooster box can allow a controlled fraction of the drilling conduit weight to be imparted to the drill bit (weight on bit) whilst the majority of the conduit remains in tension due to self-weight, in this case, no compressive forces are performed as the downward force is exerted by the weight of the conduit.
In some embodiments, maintaining a force (e.g., an upward force, downward force, etc.) on a conduit (e.g., pipeline, riser, drill pipe, etc.) can be substantially more beneficial than, for example, monitoring a load on a wellhead. Maintaining the force on the conduit can enable the ability to counteract the force before a substantially vertical displacement of the intervention devices actually occurs, thereby lowering or eliminating completely such relative movement. Thus, maintaining the force on the conduit can provide integrity to the conduit, lower the amount of movement that an intervention device can withstand, and can increase the security of workers (e.g., who no longer have to work in an environment wherein heavy elements have relative movement amongst them and between them and the workers themselves).
In both the well intervention mode and drilling mode, the rooster box can monitor for the dynamic loads (i.e., downwards or upwards force) exerted on the conduit to ensure the dynamic loads do not exceed a threshold load (i.e., a load the conduit can withstand). The rooster box can also compensate for the weight of the injector and eliminate the effect of the relative movement between the injector and the conduit. The rooster box can move relative to the conduit in order to load and push pipes down the conduit.
In some embodiments, the MODU can have a derrick attached thereto (e.g., to one or more legs of the derrick) and within the derrick a rooster box (e.g., well intervention device, traveling block, etc.). The rooster box can be adapted to move along the one or more legs of the derrick. The rooster box can be coupled to at least a conduit (e.g., riser, drill pipe, pipeline, etc.), an injector, top-drive, etc. The rooster box can have an intervention frame having two configurations: an on-axis configuration (e.g., coiled tubing configuration) and an off-axis configuration (e.g., joint-pipe configuration, wireline configuration, slickline configuration, etc.). For example, in the on-axis configuration (e.g., coiled tubing configuration) the injector can be on-axis with the conduit. In the off-axis configuration (e.g., joint-pipe configuration, wireline configuration, slickline configuration), the injector can be moved off-axis in relation to the conduit. The rooster box (i.e., the intervention fame) can be configured to change from an on-axis configuration (e.g., coiled tubing configuration) to an off-axis configuration (e.g., joint-pipe drilling configuration, wireline configuration, slickline configuration, etc.).
In some embodiments, the rooster box can include one or more working platforms. The working platform can be in a fixed position with respect to, at least, the conduit, a blow-out preventer (BOP), and/or the injector (i.e., enabling easy access the injector, the conduit, the BOP and other additional components with no relative movement between workers and the components). The one or more working platforms can provide workers with a stable platform for maintenance or supervision purposes.
In some embodiments, a skid can be coupled to an intervention frame and the injector. The skid can be configured to move the injector within the structure of the rooster box (i.e., when disengaged from the conduit). The skid can be substantially perpendicular to the conduit and can enable the injector to move off-axis in relation to the conduit. Movement of the injector off-axis can enable access to the conduit by workers and/or can enable switching the intervention frame to a different configuration (e.g., from coiled tubing to joint-pipe/wireline or vice-versa).
In some embodiments, when the intervention frame is configured in an off-axis configuration (e.g., joint-pipe configuration or wireline configuration) the rooster box can be configured for movement along the derrick. The movement of the rooster box along the derrick can be used for, first, loading the pipes to the top-drive and, subsequently, exerting a downward force to push the pipes downwards. The rooster box can also be used to prevent the load that the top-drive (and the rooster box itself) exerts on the conduit from exceeding a predetermined threshold load. In a wireline configuration, measuring equipment can be lowered from the one or more working platforms on the rooster box into the well in order to transmit electrical signals of well measurements to the surface (e.g., measurements for use in well intervention, reservoir evaluation, and pipe recovery).
One of the advantages of the present disclosure is the lack of individual heave intervention frames for each of the rooster boxes given that such heave intervention frames are normally expensive and/or rented for operations. The presence of the heave intervention frames can make it unlikely to combine different kinds of drilling tools given that, if, for example, the injector is disposed on top of the derrick by means of a coiled tubing lifting frame (CTLF) there is not enough space for a top-drive and the corresponding actuators along with the pipes required to perform joint-pipe drilling. Furthermore, a CTLF would not be an adequate solution for heave intervention in joint-pipe drilling. Moreover, CLTF are known for being unable to pass below a derrick (i.e., because of their large size) and can pose problems during operations (i.e., safety of the workers given the movement of the surfaces in offshore environments).
Disclosed are systems and methods of well intervention in a mobile offshore drilling unit. The mobile offshore drilling unit can include a derrick fixedly attached to a vessel. The mobile offshore drilling unit can also include a rooster box including an intervention frame configured to move the rooster box along the height of the derrick. The mobile offshore drilling unit can also include an injector configured to attach to the intervention frame, wherein the injector is configured to be releasably coupled to a conduit. The injector can be configured to be positioned on-axis with the conduit in a first configuration and off-axis with the conduit in a second configuration.
In some embodiments, the mobile offshore drilling unit can include a skid coupled to the intervention frame and slidingly coupled to the rooster box, wherein the skid is configured to enable the transfer the injector to the first configuration and to the second configuration. In at least one embodiment, the first configuration can be a coiled tubing mode. In at least one embodiment the second configuration can be a wireline mode. In other embodiments, the second configuration can be a joint-pipe mode.
In some embodiments, the mobile offshore drilling unit can include a top-drive located within the rooster box, the top-drive can be configured to operating in the second configuration by positioning a pipe-handler in contact with pipes fed to the top-drive by a tubular feeding machine.
In at least one embodiment, the rooster box can be configured to maintain an upright tension on the conduit. In other embodiments, the rooster box can be configured to monitor a compressive force on the conduit.
In some embodiment, the mobile offshore drilling unit can include the intervention frame being slidingly attached to one or more legs of the derrick. In some embodiments, the intervention frame can include one or more sensors configured to monitor forces exerted on the conduit. In some embodiments, the one or more sensors are load cells.
In some embodiments, the mobile offshore drilling unit can include the intervention frame having one or more actuators configured to move the rooster box along the height of the derrick for maintaining a force exerted on the conduit within a predefined range. In at least one embodiment, the actuator can be a hydraulic ram. In some embodiments, in response to detecting a loss of force on the conduit the actuators are configured to move the rooster box to maintain tension on the conduit. In other embodiments, in response to detecting an increase of force exerted on the conduit the actuators are configured to move the rooster box to maintain the force on the conduit within the threshold.
In some embodiments, the mobile offshore drilling unit can include a first working platform. In at least one embodiment, the first working platform can be configured to store the injector in an off-axis configuration. In some embodiments, the mobile offshore drilling unit can include a second working platform. In at least one embodiment, second working platform can be configured to enable access to a top-drive. In at least one embodiment, the second working platform can be configured to enable access the conduit for wireline operations.
BRIEF DESCRIPTION OF THE DRAWINGS
To complement the description being made and in order to aid towards a better understanding of the characteristics of the disclosure, in accordance with a preferred example of practical embodiment thereof, a set of drawings is attached as an integral part of said description wherein, with illustrative and non-limiting character, the following has been represented:
FIG. 1 illustrates a cross-section view through the moonpool of a vessel according to the present disclosure;
FIG. 2 illustrates a detailed view of an example embodiment of the rooster box of FIG. 1 ;
FIG. 3 illustrates a detailed view of an example embodiment of the rooster box in an off-axis configuration;
FIG. 4 illustrates a cross-section A of FIG. 2 with the intervention frame in an on-axis configuration with respect to the conduit;
FIG. 5 illustrates a cross-section A of FIG. 2 with the intervention frame in an off-axis configuration with respect to the conduit.
DETAILED DESCRIPTION
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
Several definitions that apply throughout this disclosure will now be presented. The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “substantially” is defined to be essentially conforming to the particular dimension, shape or other word that substantially modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like.
FIG. 1 illustrates an example embodiment of a mobile offshore drilling unit (MODU) 10 . The MODU 10 can include at least a derrick 3 , a rooster box 2 , injector 20 , and a conduit 4 in fluidic communication with a wellhead (not shown). The derrick 3 can be fixedly coupled to a vessel 1 (i.e., working as a supporting structure). The derrick 3 can be located over a wellhead (not shown) located on the seabed (not shown). The rooster box 2 can have relative movement with respect to the vessel 1 . In at least one embodiment, the rooster box 2 can be coupled to the conduit 4 (e.g., a pipeline, a drill pipe, a riser, etc.) and configured to keep a constant relative force (e.g., an upward tension) on the conduit 4 . The constant relative force can compensate for the movement of the vessel (e.g., heaves, etc.). The conduit 4 can include several instruments coupled therewith, for example blowout preventers (BOP) 24 , surface trees 23 , and/or other optional intermediate elements (e.g., tension relief mechanisms to avoid transferring the drill pipe tension to the wellhead).
In some embodiments, the rooster box 2 can be configured to move at least, in a linear manner along a height of the derrick 3 and perpendicular to the vessel 1 (e.g., vertically). The rooster box 2 can also monitor the force exerted by coiled tubing to the conduit to ensure the force does not exceed a predetermined threshold force (e.g., a downward force caused by the pushing of the coiled tubing).
In some embodiments, rooster box 2 can include one or more actuators 6 (e.g., a hydraulic ram at a leg of the derrick 3 ). The actuators 6 can be coupled to the rooster box 2 by cables 7 . The actuators 6 can be configured to move the rooster box 2 vertically along the legs of derrick 3 . In other embodiments, the actuators can be tuned to achieve longer action by a sheaving system.
FIG. 2 illustrates a detailed view of rooster box 2 of FIG. 1 . The rooster box 2 can include an intervention frame 25 enable to horizontally displace injector 20 . The injector 20 can be coupled to the intervention frame 25 (e.g., for support and movement). The coupling between the intervention frame 25 and the injector 20 can be made through screws, rivets, or any other suitable joining portions. The injector 20 can be releasably coupled to the conduit 4 to perform coiled tubing and joint-pipe/wireline operations. When the MODU 10 is operating in a coiled tubing configuration, the injector 20 can be moved from an off-axis configuration (i.e., with respect to the conduit 4 ) to an on-axis configuration (i.e., with respect to the conduit 4 ) and the injector 20 can be coupled to the conduit 4 . When MODU 10 is operating in a joint-pipe or wireline configuration, the injector 20 can be moved from an on-axis configuration (i.e., with respect to the conduit 4 ) to an off-axis configuration (i.e., with respect to the conduit 4 ) and the injector 20 can be decoupled from the conduit 4 .
In some embodiments, the intervention frame 25 can be coupled to a skid 22 (i.e., to which the injector 20 is to be attached). The coupling between the skid 22 and the intervention frame 25 can be made through screws, rivets, or any other suitable joining portions. Additionally, the skid 22 can enable movement of the injector 20 while maintaining the coupling to the intervention frame 25 . The skid 22 can project perpendicularly with respect to the vertical axis of the conduit 4 . The attachment of the intervention frame 25 and the skid 22 enables the injector 20 to slide along the skid 22 to change from an on-axis configuration to an off-axis configuration (as shown in FIGS. 4 and 5 ).
In other embodiments, the rooster box 2 can also include one or more sensors 29 (e.g., one or more load cells). The one or more sensors can be configured to monitor the forces exerted on the conduit 4 . In some embodiments, the sensors 29 can be located at the top of links 26 and configured to read the force exerted on load structure 27 . In some embodiments, the sensors 29 can continually monitor the forces exerted on the conduit 4 (i.e., at load structure 27 ). In response to the sensors 29 detecting a predetermined threshold force, the rooster box 2 can be adjusted (i.e., vertically) by the actuators 6 . In other embodiments, a first sensor can be configured to measure upward tension (i.e., to be maintained during coiled tubing drilling) and a second can be configured to determine the force applied by the top drive 5 (i.e., during joint-pipe drilling). The sensors 29 can be load cells, tension sensors, and/or pressure sensor, or any other sensor known in the field.
FIG. 3 illustrates the rooster box 2 configured in an off-axis configuration with an upper working platform 250 and lower working platform 251 . The top-drive 5 can be located within the rooster box 2 and can be moved to an operating position, whereas the injector 20 can be moved to an off-axis configuration position (i.e., inactive position) by intervention frame 25 . On its operating position, the top-drive 5 can be configured to position the pipe-handler 52 to be in contact with pipes that are fed to the top-drive 5 by a tubular feeding machine (not shown). In other embodiments, when injector 20 is configured in the off-axis configuration, MODU 10 can be configured for use in a wireline mode (i.e., lower measurement devices into the well for transmitting electrical measurements from the well).
The intervention frame 25 can be configured to work in different configurations (i.e., on-axis configuration and off-axis configuration). In some embodiments, where there is no longer a need to maintain a top-tension on a conduit 4 (i.e., during joint-pipe drilling operations) the intervention frame 25 can move (i.e., off-axis) to enable pipes to be fed by the top-drive 5 (i.e., joint-pipe operations). The top drive 5 can connect the pipes and, by the actuators 6 on the intervention frame 25 push the pipes through the wellhead using the movement mechanism of the rooster box 2 along the derrick 3 while measuring and ensuring the tension on the conduit is within an threshold range (i.e., to enable safe operations). Regardless of the differences of the configurations, the elements within the intervention frame 25 are substantially equivalent because, a force can be to be applied to pipes and this force can be monitored (i.e., by sensors 29 ) to ensure the force does not exceed a threshold force (e.g., a maximum operating force) on pipes (i.e., to avoid damage). The monitoring can be performed by sensors 29 configured to monitor the tension on the conduit 4 (e.g., during coiled tubing drilling an upward tension and a downward force during a joint-pipe drilling).
In some embodiments, the intervention frame 25 can include a working platform 250 to enable performance of operations and maintenance on the conduit 4 , injector 20 , the BOP, coil tubing tools, coiled tubing components, controlling well access, down hole tools, etc. The removal of relative movement between intervention frame 25 and working platform 250 enables better working conditions and improves the ergonomics and safety of workers. Working platform 250 can also be configured to store the injector 20 when in off-axis configuration. In some embodiments, a lower working platform 251 can be used for accessing the top-drive 5 , conduit 4 (e.g., during joint-pipe operations or wireline operations). Workers can also use working platform 250 and lower working platform 251 to operate MODU 10 in a wireline configuration.
In some embodiments, while operating in wireline mode workers can utilize platforms 250 and 251 for measuring and inspecting the components of well intervention device 10 (e.g., injector, drill pipe, etc.). With the use of platforms 250 and 251 , the measuring and inspecting operations can be performed expeditiously (i.e., there can be multiple workers on the platforms and the workers will no longer need to be harnessed to a crane or have to climb up the derrick to perform the operations).
FIG. 4 illustrates rooster box 2 where the injector 20 is in an on-axis configuration (i.e., with respect to the conduit 4 ). In the on-axis configuration, the injector 20 can pull pipe from a coil (not shown) through the gooseneck 21 and push the pipe through the conduit 4 . The piping being pushing through the conduit 4 can exert a downward force on the conduit 4 that can diminish the tension on the conduit 4 . In some embodiments, the intervention frame 25 can move upwards to maintain the tension on the conduit 4 . In some embodiments the intervention frame 25 can detect a loss of tension on the conduit 4 . After the detection of the loss of tension on the conduit 4 , a vertical displacement of the rooster box 2 can occur to maintain tension within a predetermined threshold. In some embodiments, tension variations can occur as a result of meteorological conditions modifying the position of a vessel with respect to a conduit 4 . In response to the tension variations, the rooster box 2 can move vertically to compensate for the tension variations caused by the meteorological conditions.
FIG. 5 illustrates rooster box 2 where the injector 20 in an off-axis configuration (i.e., with respect to the axis of the conduit 4 ). The intervention frame 25 and/or the injector 20 can be disengaged and displaced as shown by arrow 28 (e.g., either manually, automatically or semi-automatically). For example, an automatic approach can include an electrical motor to move the injector from an on-axis configuration to an off-axis configuration upon receipt of a control signal.
In some embodiments, while the injector 20 is at an off-axis configuration (i.e., with respect to the axis of conduit 4 ), the top of the conduit 4 is available for inspection (e.g., manual operations by workers supported by working platforms 250 and 251 , while the injector and/or the conduits top portion 20 remains in a substantially compensated environment—attached to the intervention frame 25 ). The inspection can be performed in a heave compensated environment (i.e., with no relative movement amongst the devices and the operators, which enables safer working conditions).
The vessel 1 can modify the working operation from a coiled tubing configuration to joint-pipe configuration by changing the configuration of the top-drive 5 from an off-axis configuration to an on-axis configuration. In another embodiment, vessel 1 can operate in a wireline mode (e.g., lower measuring devices into the well for well intervention). In some embodiments, vessel 1 can switch operations between a coiled tubing configuration and a wireline configuration approximately 40-60 times per project. Skid 22 can enable quick movement of the injection 20 (by intervention frame 25 ) from an on-axis position to an off-axis position (and vice versa). Switching the injection 20 quickly between on-axis and off-axis enables the ability to cost effectively drill evaluation wells.
Although the present invention has been disclosed in reference to a passive heave compensation system, it should be understood that an ordinary person skilled in the art would be able to modify the system to work in an active compensation system (e.g., to be able to perform coil tubing drilling operations).
Although a variety of examples and other information was used above to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of embodiments. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims.
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Mobile Offshore Drilling Units (MODUs) are more susceptible to meteorological conditions such as winds, currents and, most importantly, waves. These meteorological conditions generate a movement of the installation that will inevitably be transferred to some extent to the drilling pipe. A mobile offshore drilling unit can include a rooster box configured to move the rooster box along the height of a derrick to which it is attached. An injector configured to attach to an intervention frame of the rooster box, wherein the injector is configured to be releasably coupled to a conduit The injector configured to be positioned on-axis with the conduit in a first configuration and off-axis with the conduit in a second configuration.
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FIELD OF THE INVENTION
The present invention relates to an arrangement in a smoke shell which generates smoke in both the visible and/or IR range and/or millimeter range.
BACKGROUND OF THE INVENTION
Modern weapon systems utilize today the infrared (IR) part of the electromagnetic spectrum in addition to the visible spectrum. Especially the weapon systems which have been developed to defeat armoured fighting vehicles, comprise sighting devices operating in the infrared spectrum, which means that hostile objects can be observed and aimed at as well in daylight as in the dark.
Further, modern weapon systems utilize the millimeter band of the electromagnetic spectrum, for example in the range of 35-94 GHz, for observation, homing and destroying hostile objects.
PRIOR ART
What the prior art gives instructions for, for example as discussed in Norwegian patent application 83.3740, is that for dissemination of copper powder there must be used a separate bursting charge, i.e. a further bursting charge in addition to the charge which ignites the smoke elements.
Besides, the prior art according to Norwegian patent application 83.3740 gives instructions for smoke shells having an axial configuration, which includes a first chamber comprising smoke elements, and a second chamber comprising copper powder, said two chambers being arranged one after the other in the axial direction, and without the smoke elements and copper powder mutually influencing each other for coordinated dissemination of smoke in the visible band and the IR band or the millimeter band.
Also according to Norwegian patent application 88.1063 there is suggested on the one hand smoke generators generating visible smoke, and on the other hand a container including powder and having its own bursting charge or explosive rod. That the two types of smoke should operate separately from each other, is also obvious from this publication, since it is suggested that the two containers including smoke generating, pyrotechnical mixture are separated from the powder mixture by letting a device which initially connects the two different chambers, burst, for example by the breaking of a rod.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a smoke system giving rapid protection over a large physical area, not only in the visible band, but also in the infrared and/or millimeter band of the electromagnetic spectrum.
According to the invention this is achieved in an arrangement in a smoke shell of the type as mentioned in the preamble, which is characterized in that the arrangement comprises a first inner container housing pyrotechnical instantaneous smoke elements associated with an ignition charge, as well as a second container arranged substantially radially in relation to the first container and being without an ignition charge, and housing means for smoke in the IR and/or millimeter band, such that the reaction of the pyrotechnical instantaneous smoke elements upon ignition of said smoke shell provides a large enough pressure for bursting also the outer container for thereby disseminating the instantaneous smoke elements over a smoke screening area together with the means for providing smoke screening in the IR band and/or millimeter band.
What is novel and characterizing in the present invention, thus appears in the replacement of the bursting charge for IR and millimeter smoke with the pyrotechnical charge itself which develops instantaneous smoke, and which contributes directly to the dissemination of IR and millimeter smoke, the pyrotechnical instantaneous smoke elements upon ignition of the smoke shell rendering sufficient pressure for disseminating themselves and thereby the enclosing powder of said types of smoke.
Further advantages and features of the present invention will appear from the following description and the appended patent claims.
BRIEF DISCLOSURE OF THE DRAWINGS
FIG. 1 is a side view partly in section of a first embodiment of an arrangement in a smoke shell according to the present invention.
FIG. 2 is a section through an alternative embodiment of an arrangement in a smoke shell according to the present invention.
DESCRIPTION OF EMBODIMENTS
In FIG. 1 which illustrates a side view partly in section of a first embodiment of an arrangement in a smoke shell according to the present invention, reference numeral 1 designates an inner pipe, and this inner pipe 1 is filled with substantially disc-shaped smoke elements 2. Outside the inner pipe 1 there is provided an outer pipe 3, and in the intermediate space between the inner pipe 1 and the outer pipe 3 there is provided powder or particles 4 providing screening in the IR band and/or powder or particles providing screening in the millimeter band.
The powder or particles obscuring in the IR band comprise either separately or in combination metal powder, for example aluminum, possibly flakes of bronze or brass, graphite powder or organic salts, or similar, this powder or these particles preferably being mixed with a flow-improving or anti-agglomerating material, for example sand particles in the size band of approx. 0.3 to 1.5 mm.
The powder or the particles obscuring in the millimeter wave band comprise preferably materials which scatter or absorb such millimeter waves, for example chaff material, cut to appropriate small dipole lengths, for example 4.1 mm at 35 GHz and 1.5 mm at 94 GHz. Also here this material is preferably mixed with a flow-improving or anti-agglomerating material, for example sand particles in the size band or range of 0.3-1.5 mm.
A ratio between the IR obscuring and/or millimeter obscuring material and the flow-improving or anti-agglomerating material can appropriately be between 1:2 and 1:16.
The inner pipe 1 and the outer pipe 3 are manufactured preferably from plastic, and in the embodiment illustrated in FIG. 1, the two pipes 1 and 3 are kept together with round end plates 5 and 5', namely by means of a central bolt 6 including a washer 8 and a nut 9. Preferably the end plates 5 and 5' can be provided with circular tracks 4A, 4B and 5A, 5B, respectively, into which the end portions of the pipes 1 and 2 fit. To one of the end plates, here the end plate 5, there is attached a contact head 7 including an electrical ignition device, or ignition charge device ID, a launching charge LC and a (pyrotechnical) time delay TD.
This embodiment of a smoke shell is ignited through the pyrotechnical delay TD and the ignition ID charge. The inner pipe 1 will then burst, and the effect of the burst will immediately result in the bursting of also the outer pipe 3, such that over a large physical area there are disseminated instantaneous smoke elements generating visual smoke, at the same time as there is taking place a dissemination of the powder or the material obscuring in the IR band and/or millimeter band. This is due to the the pressure inside the smoke shell, as the outer pipe 3 bursts, and the burning instantaneous smoke discs and the entrained material for obscuring the IR band and/or millimeter band are thus disseminated with large speed. It is to be understood that the object of the flow-improving or anti-agglomerating material, for example sand particles, is its functioning as a carrier material for the powder or the particles obscuring in the IR band and/or millimeter band.
In FIG. 2 there is illustrated a section through an alternative embodiment of an arrangement in a smoke shell, comprising an inner wall 11 enclosing substantially disc-shaped smoke elements 12, as well as an outer wall 13 embracing the inner wall 11 with a certain play i.e., so that a space is defined therebetween, the intermediate space between the walls 11 and 12 being provided with a material 14 which upon dissemination obscurs in the IR band and/or millimeter band.
Also here there are provided end plates 15 and 15', respectively, holding the walls 11 and 13 together in an appropriate manner. Differently from the embodiment according to FIG. 1, there is here not used a central bolt for keeping the end plates 15 and 15' together, but instead there is provided a core of ignition charge 16. In the same manner as in the embodiment according to FIG. 1, there is in FIG. 2 attached to one of the end plates, here the end plates 15, a contact head 17 comprising an electrical ignition device, launching charge and delay unit 19, all of which is enclosed by a lid 18.
The mode of operation of this embodiment is analogue to the mode of operation of the embodiment according to FIG. 1.
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The present invention relates to an arrangement in a smoke shell rendering protection in both the visible band, and/or the IR band and/or the millimeter band.
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FIELD OF THE DISCLOSURE
[0001] The subject disclosure relates generally to the field of oilfield exploration, production, and testing, and more specifically to swellable elastomeric materials and their uses in such ventures.
BACKGROUND OF THE DISCLOSURE
[0002] Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geological formation, referred to as a reservoir, by drilling a well that penetrates the hydrocarbon-bearing formation. Once a wellbore has been drilled, the well must be completed before hydrocarbons can be produced from the well. A completion involves the design, selection, and installation of equipment and materials in or around the wellbore for conveying, pumping, or controlling the production or injection of fluids. After the well has been completed, production of oil and gas can begin.
[0003] Well pipe such as coiled or threaded production tubing, for example, is surrounded by an annular space between the exterior wall of the tubing and the interior wall of the casing or borehole wall. Frequently, it is necessary to seal this annular space between upper and lower portions of the well depth. It is often desired to utilize packers to form an annular seal in wellbores. Open-hole packers provide an annular seal between the earthen sidewall of the wellbore and a tubular. Cased-hole packers provide an annular seal between an outer tubular and an inner tubular. The sealing element of a packer is a ring of rubber or other elastomer that is secured and sealed to the interior wall surface which may be the interior casing wall or the borehole wall. By compression, for example, the ring of rubber is expanded radially against the casing or borehole wall.
[0004] Common types of packers include inflatable packers, mechanical expandable packers, and swell packers. Inflatable packers typically carry a bladder that may be pressurized to expand outwardly to form the annular seal. Mechanical expandable packers have a flexible material expanding against the outer casing or wall of the formation when compressed in the axial direction of the well. Swell packers comprise a sealing material that increases in volume and expands radially outward when a particular fluid contacts and diffuses into the sealing material in the well. For example the sealing material may swell in response to exposure to a hydrocarbon fluid or to exposure to water in the well. The sealing material may be constructed of a rubber compound or other suitable swellable material.
[0005] The benefits of using swellable seal materials in well packers are well known. For example, typical swellable seal materials can conform to irregular well surfaces and can expand radially outward without the use of complex and potentially failure-prone downhole mechanisms. Swell packers are isolation tools that utilize elastomer swelling to provide a barrier in casing/open hole and casing/tubing annuli. These packers may have a water reactive section, an oil reactive section or both. A water reactive section may consist of water-absorbing particles incorporated into a polymer. These particles swell by absorbing water, which in turn expands the rubber. An oil reactive section may utilize oleophilic polymers that absorbs hydrocarbons into the matrix. This process may be a physical uptake of the hydrocarbons which swells, lubricates and decreases the mechanical strength of the material as it expands, limiting the maximum differential pressure that can be applied across the packer. Moreover, the material deswells in the absence of a triggering fluid resulting in a loss of the annular seal upon changes to the wellbore fluid environment.
[0006] It would be an advance in the art if the elastomers used in swellable seals could be improved that when swollen are mechanically stronger and more durable. Further, it would be an advance in the art if the elastomer did not deswell in the absence of the triggering fluid.
[0007] The presently disclosed subject matter addresses the problems of the prior art by reinforcing the elastomeric composition. The presently disclosed subject matter discloses elastomer compositions that swell and stiffen but do not substantially degrade or disintegrate upon long term exposure to particular fluids.
SUMMARY OF THE DISCLOSURE
[0008] In view of the above there is a need for an improved mechanism for sealing applications. Further there is a need for an improved mechanism to reinforce the seal after swelling or setting. Finally, there is a need for the seal to remain swollen in the absence of the triggering fluid and not fully deswell. The subject technology accomplishes these and other objectives. The subject disclosure discloses a swellable downhole device, useful for downhole sealing. In non-limiting, examples, the swellable downhole device is useful for mechanical packers, swell packers or in certain situations may be used as a cement replacement. The swellable device comprises material which swells in response to a triggering fluid. The mechanism of swelling is via a chemical reaction between the reactive filler and the triggering fluid. Other triggering mechanisms may also be used, in non-limiting examples, temperature, pH or time. As used herein the term “reactive filler” is defined as a filler that undergoes a chemical reaction with the triggering fluid or another triggering mechanism. Additionally, the swellable device comprises a material that increases in volume after being triggered and also becomes less compliant.
[0009] In accordance with an embodiment of the subject disclosure a sealing system for use in a subterranean wellbore is disclosed. The sealing system comprises a seal assembly. The seal assembly comprises a base polymer and one or a plurality of reactive fillers combined with the base polymer. The seal assembly is compliant before contacting a triggering fluid and increases from a first volume to a second volume and becomes less compliant in response to contact with the triggering fluid.
[0010] In accordance with a further embodiment of the subject disclosure, a method for forming a seal in a wellbore is disclosed. The method comprises a step of providing a composition comprising a reactive filler and a base material. The method further comprises the step of deploying the composition into the wellbore and exposing the composition to a triggering fluid, thereby forming a seal in the wellbore. The formed seal isolates a particular wellbore zone from another wellbore zone or region of a subterranean formation. In non-limiting examples, the seal formed is an o-ring, a packer element, a flow control valve or a bridge plug.
[0011] In accordance with a further embodiment of the subject disclosure, a sealing system for use in a subterranean wellbore is disclosed. The sealing system comprises a swellable material. This swellable material comprises a base polymer and a reinforcing reactive filler disposed in the base polymer. The swellable material swells when in contact with a triggering fluid and is a compliant material having a first volume before swelling with the triggering fluid and is a less compliant material having a second volume after swelling with the triggering fluid.
[0012] In accordance with a further embodiment of the subject disclosure, a method of forming an annular barrier in a subterranean wellbore is disclosed. The method comprises a number of steps. The first step is the step of compounding a reactive material within a base polymer to thereby form a compliant seal assembly. The formed compliant seal assembly contacts a triggering fluid and increases from a first volume to a second volume and becomes less compliant in response to contact with a triggering fluid. Further, the compliant seal does not decrease to the first volume in response to termination of contact with the triggering fluid.
[0013] In accordance with a further embodiment of the subject disclosure, a method of constructing a well packer is disclosed. The method comprises a number of steps. The first step involves compounding a reactive material within a base polymer to thereby form a compliant well packer. The second step involves installing the compliant well packer on a base pipe. The third step involves the compliant well packer contacting a triggering fluid and increasing from a first volume to a second volume and becoming less compliant in response to contact with a triggering fluid. Finally, the compliant well packer does not decrease to the first volume in response to termination of contact with the triggering fluid.
[0014] Further features and advantages of the subject disclosure will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 is a schematic of a well system embodying principles of the present invention;
[0016] FIGS. 2A and 2B are graphs of volume change (%) and modulus ratio as a function of time for a typical oil swell material;
[0017] FIGS. 3A and 3B are graphs of volume change (%) and modulus ratio as a function of time for an improved water swelling compound described herein;
[0018] FIGS. 4A and 4B are graphs of volume change (%) and modulus ratio as a function of time for an improved water swelling compound described herein containing superabsorbent polymer (SAP) at two different concentrations: 10% mass SAP and 15% mass SAP;
[0019] FIG. 5 illustrates a graph of volume change (%) as a function of time for an improved water swelling compound described herein containing Magnesium oxide (MgO) at two different concentrations: 15% mass MgO and 45% mass MgO;
[0020] FIG. 6 illustrates a graph of % dry volume change as a function of time for an improved water swelling compound described herein containing Magnesium oxide (MgO) at two different concentrations: 15% mass MgO and 45% mass MgO. Dry volume means that samples were exposed to water for varying times as illustrated on the graph and then dried by exposure to air at 82° C.;
[0021] FIG. 7 is a stress-strain graph for an improved swelling compound according to exemplary embodiments of the present invention;
[0022] FIG. 8A is a schematic, cross-section view of a downhole tool with a deployable sealing element (a water swellable elastomer as described herein) in its initial shape; and
[0023] FIG. 8B is a schematic, cross-section view of the downhole tool of FIG. 8A where the selectively deployable sealing element has been deployed.
DETAILED DESCRIPTION
[0024] Embodiments herein are described with reference to certain types of downhole swellable fixtures. For example, these embodiments focus on the use of packers for isolating certain downhole regions in conjunction with the use of production tubing, strings, casing or liners. Further, embodiments disclosed herein may be used as an isolating material in conjunction with a production tubing, strings, casings, liners, sand-control screens, gravel pack assembly or casing hangers inside a casing or against a formation.
[0025] However, a variety of alternative applications may employ such swell packers, such as for well stimulation, completions or isolation for water injection. Additionally, alternative swellable fixture types, such as plugs, chokes, flow control valves and restrictors may take advantage of materials and techniques disclosed herein. Finally, these swellable fixtures may be used as an annular seal as an alternative to cement, in one non-limiting example, a re-entry well. Regardless, embodiments of downhole swellable fixtures disclosed herein are configured to have both reinforcement properties and a volume increase upon exposure to fluid in a wellbore.
[0026] Reinforced elastomeric compositions are described in the following co-owned patent application, which is incorporated herein by reference in its entirety: “Reinforced Elastomers,” U.S. patent application Ser. No. 12/577,121, filed, Oct. 9, 2009, and may be utilized in the construction of embodiments of downhole swellable fixtures disclosed herein.
[0027] The subject disclosure describes apparatus comprising an elastomeric material useful in oilfield applications, including hydrocarbon exploration, drilling, testing, completion, and production activities. As used herein the term “oilfield” includes land based (surface and sub-surface) and sub-seabed applications, and in certain instances seawater applications, such as when hydrocarbon exploration, drilling, testing or production equipment is deployed through seawater. The term “oilfield” as used herein includes hydrocarbon oil and gas reservoirs, and formations or portions of formations where hydrocarbon oil and gas are expected but may ultimately only contain water, brine, or some other composition. A typical use of the apparatus comprising an elastomeric component will be in downhole applications, such as zonal isolation of wellbores, although the invention is not so limited. A “wellbore” may be any type of well, including, but not limited to, a producing well, a non-producing well, an injection well, a fluid disposal well, an experimental well, an exploratory well, and the like. Wellbores may be vertical, horizontal, deviated some angle between vertical and horizontal, and combinations thereof, for example a vertical well with a non-vertical component. The use of the term “wellbore fluid” is intended to encompass completion fluids and reservoir fluids.
[0028] Representatively illustrated in FIG. 1 is a well system 101 which embodies principles of the subject disclosure. In the well system 101 , a tubular string 111 (such as a production tubing string, liner string, etc) has been installed in a wellbore 107 . The wellbore 107 may be fully or partially cased as depicted in FIG. 1 , with casing string 103 in the upper portion and uncased in the lower portion. An annular barrier is formed between the tubular string 111 and the casing string 103 by means of a swell packer 105 . Another annular barrier is formed between the tubular string 111 and the uncased wellbore 107 by means of another swell packer 113 . The swell packer 113 swells from an unexpanded state to an expanded state when it comes into contact or absorbs a triggering fluid. The triggering fluid can be present naturally in the wellbore, can be present in the formation and then produced into the wellbore, or can be deployed or injected into the wellbore. It should be understood that swell packers 105 and 113 are examples of uses of the principles of the subject disclosure. Other types of packers may be constructed, and other types of annular barriers may be formed, without departing from the principles of the subject disclosure. An annular barrier could be formed in conjunction with production tubing, strings, casings, liners, sand-control screens, gravel pack assembly or casing hangers inside a casing or against a formation. Thus, the subject disclosure is not limited in any manner to the details of the well system 101 described herein.
[0029] Downhole swellable fixtures may comprise in non-limiting examples an elastomeric material filled with a setting or reactive filler such as cement clinker (silicates, aluminates and ferrites) and may further comprise oxides such as magnesium oxide and calcium oxide. The elastomeric material may be a relatively inert rubber e.g., Hydrogenated Nitrile Butadiene Rubber (HNBR) or an oil swellable rubber e.g. ethylene propylene diene Monomer (M-class) rubber (EPDM). These reactive fillers may be activated by a plurality of different triggering mechanisms, in non-limiting examples, oil/water, time or temperature and once activated increase elastomeric stiffness. These reactive or reinforcing fillers increase the volume of the elastomer/filler composite and through experimental data it has been determined that this increase in volume primarily comes from bound water and some unbound water. The unbound water is water diffusing into the elastomer/filler composite and bound water is water which hydrates the inorganic material. As a result, even after several days in a dry environment, the volume increase remains due to hydration and bound water. The volume increase may reach in non-limiting examples about 50%. Further, the volumetric swelling may be controlled in non-limiting examples, by modifying the total amount of fillers used or using more than one filler and in these instances the volumetric increase may reach greater than about 100%.
[0030] The use of swellable materials for sealing components requires control of the swelling kinetics. The downhole swellable fixture must be deployed in its correct position before it swells and seals. The elastomer/reactive filler composites allow control of the swelling kinetics by controlling the reaction kinetics of the one or plurality of fillers as well as the permeability of the elastomer to swelling fluid, for example, water or oil. Filler type, size, shape, concentration, porosity and chemical nature, and their combinations, as well as the chemical nature of the elastomer matrix can be used to control the reaction kinetics and consequently swelling kinetics of these composite materials.
[0031] Different particle filler size results in a variation in swelling of the downhole swellable fixtures. The rate at which cement hydrates varies with the cement particle size, specifically, larger cement particles require a greater amount of time to completely hydrate. The rubber matrix will also influence the diffusion rate of fluid which will affect the reaction kinetics of fillers. In one non limiting example, a reactive filler which reacts in the presence of water will have an increase in its reaction rate with a rubber matrix which facilitates faster diffusion of water and this in turn will increase the swelling rate of the rubber/filler composite.
[0032] Conventional mechanical packers are generally composed of NBR (Nitrile Butadiene Rubber) or HNBR (Hydrogenated Nitrile Butadiene Rubber) with a reinforcing filler, for example, carbon black or silica. Conventional swell packers are generally composed of a swellable matrix, for example, ethylene propylene diene Monomer (M-class) rubber (EPDM) blends for oil swellable or swellable fillers, for example, Sodium Polyacrylate, Sodium Polyacrylamide or Clay for water swellables. The composition used for conventional packers may determine if the packer deswells if the solvent is not present anymore, for example, water in the case of water swellables. Also, the swollen material loses mechanical properties, therefore lowering the maximum differential pressure the swollen packer can withstand. FIGS. 2A and 2B show a conventional oil swellable material. The graphs are of volume change (%) and modulus ratio as a function of time for an oil swell material. Oil swellable elastomers swell by fluid absorption in the rubber matrix, and as can be seen in FIG. 2B their modulus tends to decrease as they swell and this affects the amount of differential pressure the packer is able to sustain after setting.
[0033] Embodiments of the subject disclosure disclose downhole swellable fixtures composed of a swellable matrix comprising a reactive filler which reinforces the swellable matrix after swelling or setting. Further, embodiments of the subject disclosure disclose downhole swellable fixtures composed of a swellable matrix which remains swollen after the swelling fluid is removed, for example, water. The swellable matrix disclosed in the subject disclosure may be used for sealing applications, for example, packers. The material is initially a compliant material. After the filler reacts, for example, the cement sets, the material becomes a stiffer and swollen material with hydration increasing volume.
Base Material
[0034] The base material of the seal is generally selected from any suitable material known in the industry for forming seals. Preferably, the base material is a polymer. More preferably, the base material is an elastomer. Elastomers that are particularly useful in the present invention include nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), carboxylated nitrile rubber (XNBR), carboxylated hydrogenated nitrile rubber (XHNBR), silicone rubber, ethylene-propylene-diene copolymer (EPDM), fluoroelastomer (FKM, FEPM) and perfluoroelastomer (FFKM), and any mixture or blends of the above. “Elastomer” as used herein is a generic term for substances emulating natural rubber in that they stretch under tension, have a high tensile strength, retract rapidly, and substantially recover their original dimensions. The term includes natural and man-made elastomers, and the elastomer may be a thermoplastic elastomer or a non-thermoplastic elastomer. The term includes blends (physical mixtures) of elastomers, as well as copolymers, terpolymers, and multi-polymers.
Reactive Filler Material
[0035] A reactive filler material selected from the group consisting of a cement, cementitious material, metal oxide, and mixtures thereof react and swell upon contact with water and stiffen the composite at the same time. In non-limiting examples the metal oxide is magnesium oxide, calcium oxide, manganese oxide, nickel oxide, copper oxide, berillium oxide and mixtures thereof. In other non-limiting examples the reactive filler may be a suitable epoxy comprising an epoxy resin and a hardener (or curing agent) which may react (or polymerize) together over time or temperature. The epoxy may further contain a suitable diluent. Polymerization of epoxy is called “curing”, and can be controlled through temperature and choice of resin and hardener compounds; the process can take minutes to hours. Some formulations benefit from heating during the cure period, whereas others simply require time, and ambient temperatures. Some common epoxy resins include but not limited to: the diglycidyl ether of bisphenol A (DGEBA), novolac resins, cycloaliphatic epoxy resins, brominated resins, epoxidized olefins, Epon® and Epikote®. Examples of hardeners include but not limited to: Aliphatic amines such as triethylenetetramine (TETA) and diethylenetriamine (DETA); Aromatic amines, including diaminodiphenyl sulfone (DDS) and dimethylaniline (DMA); Anhydrides such as phthalic anhydride and nadic methyl anhydride (NMA); Amine/phenol formaldehydes such as urea formaldehyde and melamine formaldehyde; Catalytic curing agents such as tertiary amines and boron trifluoride complexes. Diluents and solvents are used to dilute or thin epoxy resins. Some examples are: Glycidyl ethers (reactive diluents) such as n-butyl glycidyl ether (BGE), isopropyl glycidyl ether (IGE) and phenyl glycidyl ether (PGE); Organic solvents such as toluene (toluol), xylene (xylenol), acetone, methyl ethyl ketone (MEK), 1,1,1-trichloroethane (TCA), and glycol.
[0036] In non-limiting examples the cement is a Portland cement or a mixture of slag and Portland cement. Further examples include Portland cement blends, non-limiting examples include Portland blast furnace cement, Portland flyash cement, Portland pozzolan cement, Portland silica fume cement, masonry cements, expansive cements, white blended cements and very finely ground cements and mixtures thereof. Finally, non-Portland hydraulic cements may also be used, non-limiting examples include Pozzolan-lime cements, slag-lime cements, supersulfated cements, calcium aluminate cements, calcium sulfoaluminate cements and geopolymer cements. These filler materials improve the physical properties of the composition by acting as a reactive filler material. These fillers may impart many advantages to the composite materials produced from the formulations, such as increased volume and increased modulus. Embodiments of the subject disclosure disclose reactive fillers dispersed within a polymer matrix, wherein the reactive fillers swell on contact with water due to hydration and phase modification of the fillers upon reaction with a triggering fluid, in one non-limiting example, water. Reactive fillers in one non-limiting example are cement-like particles, about 1-50 microns, composed of Portland cement or a mixture of slag and Portland cement. FIGS. 3A and 3B are graphs of volume change (%) and modulus ratio as a function of time for an improved water swelling compound described herein. The novel water swelling compounds show an increase in modulus with swelling. FIG. 3A compares the volume change (%) with time for a pure rubber sample and samples containing Portland cement or a mixture of slag and Portland cement or a mixture of slag, Portland cement and MgO. The pure rubber sample has a volume change (%) of about ˜10%. The samples with Portland cement or a mixture of slag and Portland cement respectively swell to ratios of about ˜70% and ˜30%. Finally, the sample with cement and MgO swells to about 110%. FIG. 3B shows the increase in modulus of each of the samples. The pure rubber sample maintains the same modulus ratio over time. The rubber and Portland cement sample increases its modulus by a factor 10 over time. There is also an increase in the modulus ratio of samples containing rubber and a mixture of slag and Portland cement or rubber and a mixture of slag, Portland cement and MgO. MgO and other suitable oxides hydrate upon exposure to an aqueous fluid, in a non-limiting example, to an aqueous fluid during production. The hydration products of suitable oxides are less dense; therefore; there is a corresponding volume increase when they react with an aqueous fluid, e.g., water. Other suitable oxides include CaO, MnO, NiO, BeO and CuO and combinations thereof.
Manufacturing the Elastomeric Samples
[0037] The elastomeric compositions useful in downhole swellable fixtures of the subject disclosure may be readily made using conventional rubber mixing techniques e.g. using an internal rubber mixer (such as mixers manufactured by Banburry) and/or a twin roll mill (such as mills manufactured by PPlast). In non-limiting examples cement powder is added to rubber gum during mixing. Other materials such as Magnesium Oxide (MgO) or Super Absorbent Polymers (SAP) may also be added.
Superabsorbent Polymers (SAP) or Hydrogels
[0038] Recently there has been a growing interest in swellable elastomers for use in oilfield applications. In order to make elastomers swell in water, previous publications have disclosed elastomer formulations that contain superabsorbent polymers like hydrogels (Report #RUS 1-1464-ST-04, Institute of Rubber coatings and products, L. Akopyan, Moscow Research center and references therein). The main drawback of using hydrogels is that hydrogel containing swellable polymers do not possess long term physical integrity. This is because the hydrogel particles embedded in the elastomer tends to migrate to the surface of the elastomer part and into the water phase. As a result, elastomer/hydrogel blends show a nonuniform swelling and develop blisters on the surface when exposed to water. After a few days of exposure to water these blisters burst open and hydrogel particles are ejected out of the blend leaving behind cracks in the elastomer.
[0039] Water swellable packers often incorporate hydrophillic, swelling polymers (sometimes referred to as “superabsorbing particles” for example, cationic, anionic or zwitterionic polymers in an elastomeric matrix. Non-limiting examples include Polyacrylic acid, polymethacrylic acid, polyacrylamide, polyethyleneoxide, polyethylene glycol, polypropylene oxide, poly (acrylic acid-co-acrylamide), polymers made from zwitterionic monomers which includeN, N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(3-sulfopropyl)-ammonium betaine, 2-(methylthio)ethyl methacryloyl-S-(sulfopropyl)-sulfonium betaine, 2-[(2-acryloylethyl)dimethylammonio]ethyl 2-methyl phosphate, [(2-acryloylethyl)dimethylammonio] methyl phosphonic acid, 2-(acryloyloxyethyl)- 2 ′-(trimethylammonium)ethyl phosphate, 2-methacryloyloxyethyl phosphorylcholine, 2-[(3-acrylamidopropyl)dimethylammonio]ethyl 2′-isopropyl phosphate, 1-vinyl-3-(3-sulfopropyl)imidazolium hydroxide, (2-acryloxyethyl)carboxymethyl methylsulfonium chloride, 1-(3-sulfopropyl)-2-vinylpyridinium betaine, N-(4-sulfobutyl)-N-methyl-N,N-diallylamine ammonium betaine, N,N-diallyl-N-methyl-N-(2-sulfoethyl)ammonium betaine and the like. Superabsorbent polymers are hydrophilic networks which can absorb and retain huge amounts of water or aqueous solutions. These superabsorbing materials exhibit very fast kinetics of swelling which is useful for sealing applications. However, as discussed above these materials do not possess long term physical integrity. Further, a large amount of SAP fillers are often required (−30-40% by weight of the composite) to achieve swelling, resulting in a significant strength reduction upon swelling. A further limiting aspect of SAP materials is sensitivity to salt concentration, tending to deswell upon exposure to brine which results in loss of zonal isolation.
[0040] The present disclosure discloses a further embodiment of a downhole fixture comprising elastomeric material compounded with reactive fillers and SAP for use in swellable fixtures. The advantages of this embodiment are that SAP will absorb a large quantity of water and this water will then be available to the reactive fillers, thereby increasing the reaction rate and hence the swelling rate of the reactive fillers. The reactive fillers provide both swelling and reinforcement to the material thus providing long term physical integrity. Further, the amount of SAP needed is reduced as the SAP functions mainly for initial water uptake and the reactive filler provides the swelling.
[0041] Embodiments of the subject disclosure comprising elastomers and reactive fillers have a slower rate of swelling when compared to oil swellable elastomers. To improve the efficiency of water transport SAP may be used. Rubber compositions containing SAP fillers have often been used in the past to make water swellable packers. See commonly owned, U.S. Pat. No. 7,373,991, entitled “Swellable elastomer-based apparatus, oilfield elements comprising same, and methods of using same in oilfield applications”, filed Mar. 27, 2006, the contents of which are herein incorporated by reference.
[0042] Embodiments of the subject disclosure disclose elastomeric compositions suitable for downhole swelling fixtures comprising reactive fillers and a small percentage of SAP. FIGS. 4A and 4B are graphs of volume change (%) and modulus ratio as a function of time for an improved water swelling compound for use in downhole fixtures described herein containing superabsorbent polymer (SAP) in addition to cement at two different concentrations: 10% mass SAP and 15% mass SAP. The samples swell rapidly especially in the first few hours due to the addition of SAP and the ability of SAP to absorb a large amount of water. The greater the amount of SAP added initially the higher the swelling ratio in the first few hours. The sample with about 15% of SAP swells to about 140% versus the sample with 10% which swells to about 60%. However, after some time, the swelling ratio of the samples decreases to equilibrium of about 50%-60% similar to the sample with no SAP added. The addition of SAP results in a significant increase in the volume of rubber even at very short durations. Volume increase is a result of the rapid absorption of water by SAP. SAP also is a water source for cement hydration resulting in faster hydration of cement. FIG. 4B shows the modulus increase with varying amounts of SAP. The modulus of samples containing SAP reduces significantly in the first few hours from an initial modulus of about 1 to as low as 0. The modulus increases again over time and the sample containing the highest amount of SAP (15%) has the highest percentage modulus increase of about 500% or by a factor of about 6. The increased availability of water inside the rubber matrix increases the rate of cement hydration, thus, increasing the modulus of the rubber matrix. The addition of SAP increases both the kinetics of swelling and stiffening upon incorporation of SAP to embodiments of the subject disclosure. Further, the rubber matrix is reinforced which is a significant advantage compared to rubber matrices containing only SAP which become soft upon swelling and therefore results in failure of the material under a high differential load.
[0043] FIG. 5 illustrates a graph of volume change (%) as a function of time for an improved water swelling compound for use in downhole fixtures described herein containing magnesium oxide (MgO) at two different concentrations: 15% mass MgO and 45% mass MgO. An increase in MgO compounded with cement increases the amount of swelling. The sample with 45% MgO has a volume change (%) of about 110% versus the sample with 15% MgO having a volume change of about 60%.
[0044] FIG. 6 illustrates a graph of % dry volume change as a function of time for an improved water swelling compound for use in downhole fixtures described herein containing magnesium oxide (MgO) at two different concentrations: 15% mass MgO and 45% mass MgO. Samples were exposed to water for varying times as illustrated on the graph and then dried by exposure to air at 82° C. The samples remained partially swollen after drying with a volume change (%) of about 80% for the sample containing 45% MgO.
[0045] FIG. 7 is a stress-strain graph for an improved swelling compound for use in downhole fixtures described herein according to exemplary embodiments of the present invention. The rubber/cement composite exhibits a large increase in strength after drying.
Brine Insensitive Water Swellable Polymers
[0046] Embodiments of the subject disclosure may need to swell in the presence of brine. As used herein, the term “brine” is meant to refer to any water-based fluid containing alkaline or earth-alkaline chlorides salt such as sodium chloride, calcium chloride, etc, sulphates and carbonates. The swelling characteristics may be variable in relation to the variability in salt concentration of the brine. That is, as the salt concentration increases, the amount of swell will also increase. It is important to have a seal whose swelling is less sensitive to the changes in brine concentration. The elastomer backbone of embodiments of the subject disclosure may be tailored with particular concentrations of cations and/or anions grafted thereto so as to reduce the sensitivity thereof to brine concentration. Materials may be used that swell to a given degree upon exposure to brine in the well. Additionally, the given degree of swell for the material remains substantially constant where the brine concentration fluctuates. Embodiments of the subject disclosure disclose a swellable fixture, in one non-limiting example a packer configured of brine-insensitive materials combined with reactive fillers.
Packer Seal Test Experiment
[0047] A mini-packer of an oil swellable material and a mini-packer of HNBR rubber, cement and MgO in varying percentages were tested and compared using methods known to those skilled in the art. The oil swellable packer failed at a differential pressure of about 1,200 psi and major material extrusion which is related to poor mechanical properties was observed. The novel water swellable packer failed at a differential pressure of 11,000 psi and minor material extrusion which is related to good mechanical properties was observed.
[0048] An example of using the water swellable elastomers described herein on a downhole tool 801 , in a specific case a packer, is schematically illustrated in FIGS. 8A and 8B . FIG. 8A shows the sealing assembly 805 which comprises a seal assembly of the subject disclosure in a first or initial compliant state which has formed around a tubing 803 . The first or initial compliant state allows the downhole tool to be put in the correct place easily. After contact with water or brine, the sealing assembly 805 will expand, swell to a second less compliant state or volume 819 , and will then conform to the borehole wall 821 of the subterranean formation 815 . In this manner, wellbore 813 is sealed.
[0049] While the subject disclosure is described through the above exemplary embodiments, it will be understood by those of ordinary skill in the art that modification to and variation of the illustrated embodiments may be made without departing from the inventive concepts herein disclosed. Moreover, while the preferred embodiments are described in connection with various illustrative structures, one skilled in the art will recognize that the system may be embodied using a variety of specific structures. Accordingly, the subject disclosure should not be viewed as limited except by the scope and spirit of the appended claims.
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The subject disclosure discloses apparatus and methods that are particularly suited for creating a seal in a borehole annulus. More particularly, the subject disclosure discloses a seal with enhanced sealing capability. In one embodiment the subject disclosure discloses a reinforced and permanent swellable packer device.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for processing dusts and muds from dust removing plants in the iron and steel industry where the dusts are pelletized for further processing.
During the dust removal from waste gases of metallurgical plants, such as blast furnaces, converters, electrofurnaces and sintering plants, a large quantity of dust-like matter is produced which should be dressed and further processed, particularly due to its considerable iron content.
Dust-like matter may develop, depending on the type of dust removal process employed, either in dry dust removal plants as a dry dust, or in wet dust removal plants as a water-dust dispersion. The water-dust dispersion can be concentrated in such a manner that a mud is deposited from the dispersion in a thickener while clear water flows out through an overflow of the thickener.
In the production of raw iron, 5 to 20 kg dust are developed in blast furnace dust removal plants per ton of raw iron. In the production of steel in LD converters, 18 to 21 kg dust are developed per ton of steel. The exact quantities of dust developed depend on the size of the metallurgical plant, the raw materials employed, and the mode of operation involved.
The use of dusts and muds in sintering systems is very limited due to the very fine consistency of the solid matter and due to the varying contents of zinc, lead and alkalis which have an adverse influence on blast furnace operation. Dumping of such substances is sometimes also not possible due to environmental protection laws.
Due to the relatively high iron, zinc and lead contents, these substances are dressed and processed either as dry dust, mud or a mixture of the two. One prior proposal for treating the dust material provides for pelletizing the dust material together with iron ore concentrate to form green pellets. The green pellets are then prehardended on a traveling grate and thereafter are reduced in a series-connected cylindrical rotary kiln with the addition of solid fuels whereby zinc and lead volatilize. The resulting products are metallized pellets containing relatively small quantities of zinc and lead. These metallized pellets, however, have a relatively high sulfur content so that use thereof is possible mainly in blast furnaces. There further exists the danger of the green pellets sintering together on the traveling grate since carbon is always present in the blast furnace dusts. To avoid such sintering together, it is necessary, in the above-mentioned processes, to add relatively large quantities of fine ore as a leaning material to the mixture which is formed into the green pellets, or to prevent that oxigen may enter into the grate area.
In the past, binders, such as bentonite, calcium hydroxide, starch, limestone, and other similar materials, have been used in the production of pellets. In addition, oil and pitch have been used as binders.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a process which avoids the above-mentioned drawbacks, i.e., which operates without a traveling grate in the processing of mixtures of dry dusts and/or muds and permits the production of metallized pellets which are substantially free of zinc, lead and alkalis.
A further object of the present invention is to provide a process for producing pellets without the use of binders.
Additional objects and advantages of the present invention will be set forth in part in the description which follows and in part will be obvious from the description or can be learned by practice of the invention. The objects and advantages are achieved by means of the processes, instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing objects, and in accordance with its purposes, the present invention, as embodied and broadly described, provides a method for processing dusts and muds from dust removal plants in the iron and steel industry where the dusts and muds are pelletized for further processing. The method comprises: forming green pellets by pelletizing the dust material with a moisture content of 10 to 16 weight-% for less than 6 minutes with the addition of water only such that the moisture content of the green pellets is between 17 to 30 weight-%; and introducing the green pellets--together with a reducing agent--directly into a rotary kiln to reduce the green pellets.
In the practice of the present invention, no addition of any kind of binder or ore or ore concentrate is required.
DETAILED DESCRIPTION OF THE INVENTION
In the practice of the present invention, the dust material to be pelletized can be the dry dust resulting from dry dust removal plants or the mud resulting from the wet dust removal plants, or a mixture of the dry dusts and muds.
Before pelletization, the dust material to be pelletized comprising dry dusts and/or muds is homogenized, moistened, and respectively dried to a residual moisture of 10 to 16 weight-%. If the pelletization is based on moisture contents in the material to be pelletized of less than 8 weight-%, the resulting green pellets will be very dense due to the very fine consistency of the dusts which have a specific surface according to Blaine of 5,000 to 12,000 cm 2 /g and such pellets must be dried very carefully in order to avoid dry cracks and bursting. This requires drying times of 20 to 40 minutes. Accordingly, care is taken in the practice of the present invention to provide in the material to be pelletized a moisture content of 10 to 16%.
A further significant feature of the present invention is that the period of dwell of the material to be pelletized on the pelletizer must be less than 6 minutes, and preferably, is between 3 and 5 minutes. If the period of dwell is longer, the pellets will become so moist at the surface due to water squeezed out that they become superplastic or turn into mud.
Finally, in the present invention, the moisture content of the green pellets must be controlled to be at 17 to 30 weight-%, preferably 18 to 25 weight-%. This moisture content of the green pellets is obtained by controlling the dwell time and amount of water added to the pelletizer. This moisture content has the advantage that these green pellets need neither be dried nor prehardened, but can be introduced directly into a cylindrical rotary furnace together with a reducing agent. The solid reducing agents or fuels that can be used include anthracite, coke fines, low-temperature coke and/or highly volatile coal, e.g., soft coal. The green pellets contain oxidized material, such as metal oxides of iron, zinc and lead, which are reduced during passage through the rotary furnace.
According to a preferred embodiment of the invention, the green pellets are introduced into a cylindrical rotary furnace which has a drying and preheating zone and are heated in the rotary kiln to a temperature of between 900° and 1,100° C. The temperature profile in the rotary kiln can be set via air nozzles distributed over the length of the kiln so that advisably two-thirds of the length of the furnace has a temperature of between 900° and 1,100° C. In this case, the first third of the furnace serves as a drying and preheating zone for the charge of green pellets and the solid reducing fuels.
Operation at the above-mentioned operating temperatures is required for the reduction of iron, zinc and lead oxides and alkali carbonates that are in the green pellets. Zinc and lead then will leave the charge in the form of metal vapor, re-oxidize in the free kiln room and leave the furnace in solid form together with the waste gas. These oxides are advantageously collected in a bag filter of electrofilter.
The alkalis carbonates in the pellets are reduced during passage through the rotary kiln too. The volatilization of the alkalis mainly occurs in the form of metal vapor which recarbonates in the free kiln room. Potassium volatilization starts at about 780° C., whereas sodium volatilization does not begin until about 880° C.
The reduced metallized pellets are discharged from the rotary furnace in the form of sponge iron together with the excess fuel and ashes. This mixture is cooled in a cooling drum and dressed by sifting and magnetic separation.
The following example is given by way of illustration to further explain the principles of the invention. This example is merely illustrative and is not to be understood as limiting the scope and underlying principles of the invention in any way. All percentages referred to herein are by weight unless otherwise indicated.
A mixture of 60% predried LD mud and 40% predried shaft furnace mud is homogenized. This mixture has a moisture content of 12%. The most important components of the mixture are:
Fe total =42.2%
Zn=5.3%
Pb=1.61%
Na 2 O=0.8%
K 2 O=0.35%, and
C=5.8%
The above mixture is introduced into a pelletizer containing a pelletizing plate having a diameter of 1 m. Green pellets with a grain diameter between 8 and 20 mm are produced with the addition of water. These green pellets have a moisture content of 22.7%, a green strength of 2 kp/pellet, and an impact strength such that they can survive more than 20 falls from a height of 450 mm without forming cracks.
The green pellets, together with coke fines of a grain size up to 3 mm as the reduction fuel, are continuously charged directly into a rotary furnace. The rotary furnace is heated from the discharge end with coke furnace gas in countercurrent with respect to the flow of charged material. Over two-thirds of the length of the furnace, the temperatures of the material being treated are between 900° and 1,100° C. so that the alkalis will substantially volatilize.
For a specific throughput of 0.64 t of green pellets/m 3 of furnace area and per day, the degree of metallization is an average of 93%. The zinc and lead volatilization lies at 99%. Average zinc contents of 0.055% and lead contents of 0.008% are realized in the metallized pellets. The volatilization of alkalis, with respect to the amount of material charged, is about 80% for sodium oxide and up to 95% for potassium oxide.
The proportion of fine sponge iron of a size <4 mm is only 20%. An oxide with the following analysis is deposited in the bag filter:
Zn=35%
Pb=15%
Fe total =15%
C total =10%
Na 2 O=1.1%
K 2 O=0.7%
This metal oxide can be further enriched either in a zinc-waelz-plant or by wet chemical processes.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A method is provided for processing dusts and muds from dust removing systems in the iron and steel industry by pelletizing them for further processing. Green pellets are formed by pelletizing the dusts and/or muds with a moisture content of between 10% and 16% for less than 6 minutes with an addition of water such that the moisture content of the green pellets is between 17% and 30%. The green pellets, together with a reducing agent, are then introduced into a rotary furnace.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for producing a continuous succession of pieces or sheets, particularly suitable for infeeding cut pieces of wrapping material to wrapping machines.
To be more precise, the apparatus according to the invention envisages a fresh, or standby, or second reel automatically replacing a first reel of material when the latter has been used up, without this affecting the continuity in the succession of the sheets or cuttings obtained from the said material wound on to individual reels.
THE TERMS "FIRST" AND "SECOND" REEL MENTIONED HEREIN ARE PURELY INDICATIVE SINCE THE POSITIONS OCCUPIED BY THE TWO REELS ALTERNATE BETWEEN ONE AND THE OTHER DEPENDING UPON WHETHER THE REEL IS SUPPLYING MATERIAL OF IF IT IS ACTING AS THE STANDBY REEL.
DESCRIPTION OF THE PRIOR ART
According to the known practice in this particular field, the strip or web of wrapping material is unwound from each reel by means which can consist of a pair of rollers known as infeed rollers, the spindles of which are parallel to each other, in close contact with each other. The said strip or web of wrapping material is subsequently divided up into sheets or cuttings of a given length by a cutting device.
When the said sheets or cuttings are required for immediate use, after various transfer operations they are delivered, along with the products to be wrapped, to the actual wrapping machine.
In the known technique for supplying wrapping machines, the problem of replacing a finished reel with a fresh reel has been solved in different ways. Devices have, for example, been perfected for splicing, by means of sealing or gluing members, the final section of the web on the reel that is about to run out to the free end of the new reel, in such a way as to guarantee continuity in the supply of the wrapping material to the wrapping machine.
In this particular case the final section of the material being taken from the first reel serves to move forward the material from the second reel, until it is inserted between the infeed rollers. The splicing is controlled by means which come into action automatically as the material from the first reel is about to come to an end.
An alternative way in which this matter has been solved dispenses with the use of the aforementioned sealing or gluing members and when the material from the first reel is coming to an end, an auxiliary supply system composed of rollers, known as pre-infeed rollers, comes into operation, initially unwinding the material from the standby reel, until the free end has been inserted between the infeed rollers.
This method too guarantees continuity in the supply of the wrapping material since the free end of the material from the new reel arrives at the infeed rollers at a time when the material from the first reel is still sliding between them. As in the previous case, for a certain interval of time two spliced or superposed strips are fed to the single cutting device. However, the spliced strips are not, in the latter case bonded together with glue or by means of sealing or welding.
In harmony with the aforementioned methods, reel change devices have been prepared, equipped either with one auxiliary infeed system connectable with one reel or with the other, or else equipped with two auxiliary independent infeed systems, one per reel.
The system of pre-infeed rollers, in keeping with what has been seen previously, automatically comes into operation at the time each reel runs out.
As a consequence of the foregoing, whilst the known systems guarantee the operational continuity of the wrapping machine during the changeover from one reel to another, they cause the device for cutting the material into pieces and subsequently the wrapping machine too to handle, at the time in question, sections of material which has been spliced and is twice its normal thickness.
The repercussions of this, besides being obviously adverse from a financial point of view, also are such that both the cutting device and the wrapping machine are compelled to operate in an abnormal fashion and handle wrapping material of a mechanical strength above that which is customary.
In addition to an inevitable waste of wrapping material, in the majority of cases it is also necessary, because of their appearance, to reject products wrapped in the said pieces of spliced material, and to replace the rejected products with others taken from a reserve stock.
SUMMARY OF THE INVENTION
The object of the present invention is, therefore, to overcome the aforementioned difficulties by making available an apparatus of the type to which reference has been made above, suitable to be connected to a wrapping machine and able to automatically cause an empty reel to be replaced with a fresh reel without any interruption in the operation of the wrapping machine and, furthermore, to allow, whilst the replacement operation is in progress, the cutting means and the wrapping machine itself to operate under perfectly normal conditions without there being any waste of material or any need to provide, for the reasons previously seen, rejection devices below the wrapping machine.
The new apparatus produces, from successive webs of material, a continuous succession of pieces or sheets, particularly suitable for infeeding cut pieces of wrapping material to wrapping mcahines. The apparatus comprises a track for collating and sending forward the said sheets or cuttings; a plurality of auxiliary tracks leading to the said collation track; means for channelling along the auxiliary tracks, successively material from respective reels. According to the invention the apparatus has control means for rhythmically cutting such material for automatically feeding material, end to end, from a fresh reel on exhaustion of an empty reel. The control means comprise sensor means for detecting the end of the material from the empty reel. It is an essential features of the new apparatus that the control means enable cutting from the end of the initial web of a piece material equal in length to, or a multiple of, the length one of the said sheets or cuttings and to thereupon cause material to move forward along another of the said auxiliary tracks so that there is a continuous succession of sheets or cuttings along the above mentioned track where the said sheets or cuttings are collated and sent forward. The control means enable operating the infeed means belonging to the track ending at the standby reel in such a way that the wrapping material from that reel is delivered to the main track, after the end of the material from the empty reel, so that also in the transition from one reel to the other an unbroken sequence of wrapping material in the form of cuttings is fed to the wrapping machine.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages will emerge more clearly from the following detailed description of certain preferred forms of embodiment for the apparatus according to the invention, illustrated as non-limiting examples on the accompanying drawings in which;
FIG. 1 shows a front view in diagrammatic form, of the apparatus according to a first embodiment of the invention;
FIG. 2 schematically shows the electrical control circuit for the said first embodiment;
FIG. 3 shows a plan view, in diagrammatic form, of a further embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, at B1 there is a first reel of wrapping material mounted in a rotatable fashion on a horizontal spindle, from which the material N1 is unwound by a pair of infeed rollers R1 and R2 mounted on horizontal parallel spindles.
Below the rollers R1 and R2 a cutting device operates and this consists of a roller C1 provided with a blade which operates in conjunction with a counter-roller C2, the task of this assembly being to divide the continuous strip of material N1 up into the cuttings S for them to be utilized by a wrapping machine not shown on the drawing.
The infeed rollers R1-R2 and the rotating knives C1-C2 define a vertical infeed track for the wrapping material and this lies on a plane hereinafter referred to as the main plane or track and represents, in the particular form of embodiment described herein, a plane of symmetry for the complete device.
Two rollers r1 and r2 mounted on horizontal parallel spindles are postioned immediately below the reel B1 and these, which work on conjunction with each other, have the task of acting as a system for the auxiliary infeed or pre-infeed of the material N1 from the reel B1.
In conjunction with the rollers R1 and R2, the said pre-infeed rollers r1 and r2 define, in turn, a plane or pre-infeed track for the material N1 from the reel B1 which is not coincident with the above mentioned main plane or track.
Between the said pre-infeed rollers r1 and r2 and the reel B1 a sensor device F1 is provided and this detects the end of the material N1 from the said reel B1, whilst below the said rollers r1 and r2, along the said pre-infeed track, an auxiliary cutting device consisting of a roller c2 provided with a blade and operating in conjunction with a counter-roller c1 is positioned. Additionally along the pre-infeed track for the material N1, in the area in between the device c1-c2 and the rollers R1 and R2 a fixed guide G1 is placed and the function of this will be seen in due course.
A second reel B2 of material N2 referred to hereinafter as the new or reserve reel is mounted in a position symmetrical to the first reel B1 with respect to the main infeed plane. Two rollers r1' and r2' constitute the auxiliary infeed system for the reel B2, whilst at c2' there is a roller provided with a blade and this, in conjunction with a counter-roller c1', infeeds the material N2.
In conformity with what has already been stated for the two reels, the rollers r1' and r2' are mounted symmetrically to the pre-infeed rollers r1 and r2 of the reel B1 with respect to the main infeed plane, whilst the cutting system c1' and c2' is symmetrical to the cutting system c1 and c2 for the material N1, with respect to the said plane. The same applies for a fixed guide G2 in relation to the aforementioned guide G1 and for a sensor device F2 in relation to the sensor device F1.
As a consequence of this, the pre-infeed track for the reel B2, defined by the pre-infeed rollers r1' and r2' in conjunction with the main infeed rollers R1 and R2, is symmetrical with the pre-infeed track for the reel B1, with respect to the main infeed plane.
Up until now a description has been given of the structural layout of the essential units constituting one particular form of embodiment for the apparatus according to the invention and now its operation, also with reference to the electrical diagram in FIG. 2 will be examined.
Assuming the apparatus to be working under normal operating conditions, the infeed rollers R1 and R2, one at least of which is a driven roller, unwind the material N1 from the reel B1 and feed it to the cutting device C1 and C2 which divides the said strip of material up into cuttings S of a predetermined length.
Under these conditions the two auxiliary infeed rollers r1 and r2 rotate loosely around their spindles moved by friction by the material N1, whilst the cutting device c1 and c2 is in the reset position and the blade fitted to the roller c2 is rotated at a certain angle away from the infeed path for the material N1.
As the reel B1 continues to be unwound, the material N1 wound thereon gradually decreases until it comes completely to an end, that is to say, until it separates from the reel carrier spindle and when this occurs the sensor device F1 causes the contact T1 to close (see FIG. 2) through connections to which are well known by themselves.
The impulse of current generated by the closing of the contact T1 is sent to a first input on the AND gate 1.
The AND gate 1 is provided with a second input energized through the closing of a contact T. This latter contact T is cyclically closed after each complete revolution, that is to say, after each 360° of rotation, of a cam 2 keyed on to the spindle of the main cutter roller C1. The simultaneous occurrence of the two events, that is to say, the presence of two impulses of current on the inputs of the AND gate 1 generates a signal in the output circuit of this gate, in a way known by itself. This signal, duly memorized and amplified by a memory 3 and an amplifier 4, respectively, is used to operate, for example, by engaging a clutch 5 having discs 5a, 5b, the auxiliary cutting device c1-c2 belonging to the reel B1.
The operation of the auxillary cutting device c1-c2, controlled in the way seen above, is regulated so as to detach from the material N1 on the finished reel B1 a final piece of a length L which is a multiple of the length l of each individual cutting S, that is to say, L = nl.
This is done, for example, by suitably regulating the position of the blade c1 of the device c1-c2 with respect to the infeed plane of the reel B1, in such a way that the cut is made at the required point, in keeping with the ratio indicated above.
The final detached section of the material N1, having length L and drawn along by the infeed rollers R1 and R2 is cyclically divided by the cutting device C1-C2 into n cuttings S which are thus fully utilizable by the wrapping machine.
In order, however, that below the cutting device C1-C2 there be an unbroken and uniform succession of cuttings S from material on the main infeed track, even at the time the operation of replacing one reel B1 with the other B2 is being carried out, there must be continuity in the delivery of the materials N1, N2 (that is to say, it must follow N1 without any pause and also without any superposition).
Assuming, for reasons of simplicity, that the infeed speed of the rollers R1 and R2 is equal to that of the rollers r1' and r2' and bearing in mind that the structure of the device is symmetrical, it is necessary, in order to achieve the above mentioned conditions, that once the free end of the material N2 has been fastened in a suitable position Y' on the infeed track guide G2 of the reserve reel B2, this material starts to move at the very moment when the final extremity of the material N1 passes, on the infeed track of the reel B1, into the corresponding position Y symmetrical with Y'.
In this way, at the point where the infeed track for the material on the reel B1 converges with that for the material on the reel B2, the free end of the material N2 will follow on immediately after the final extremity of the material N1.
It should be noted that in consequence of what has been said in connection with the dimension L of the final detached section of the material N1, the cutting devicd C1-C2 will operate once without cutting anything between the last cutting S of the material N1 and the free end of the material N2.
With this particular form of embodiment for the apparatus forming the subject of the present invention, the foregoing is achieved by picking up the signal for operating the cutting device c1-c2 at the output of the memory 3 and by sending it to the first element or cell of a shift register 6, the shift signal for which is additionally generated by the cyclic closing of the contact T by the cam 2.
When the leading edge of the final detached piece of the material N1 passes into the position Y, the signal from the output of the shift register 6, duly amplified by an amplifier 7, is sent forward to operate, through the engagement of a clutch 8 having discs 8a, 8b, the auxiliary infeed device r1'-r2' belonging to the reel B2.
The number of steps for the above mentioned shift register 6, which in this particular instance is two, represents, in cycles, the time lag established for the commencement of the infeeding of the material N2 with respect to the instant when the auxiliary cutting device c1-c2 operates.
Since it is advisable, for various reasons, to position the free leading end of the material N2 in the proximity of the infeed rollers R1 and R2, not only will the number of steps depend on the distance between the cutting device c1-c2 and the rollers R1 and R2 but also on the length l of the cuttings S.
The free leading end of the material N2 is pushed by the rollers r1'-r2' from the position Y' through the guides G2 in such a way that it is inserted between the infeed rollers R1 and R2 without any discontinuity with respect to the final extremity of the detached material N1.
When the reel B2 comes to an end, the procedure described above is repeated but, as is understandable from the symmetry of the apparatus and from the electrical control circuit, in this particular case the devices concerned are the sensor device F2, the cutting device c1'-c2', the auxiliary infeed rollers r1-r2 and the electrical devices corresponding thereto (see FIG. 2).
In addition to the devices already mentioned, the electrical control circuit is also provided with a magnetic memory 9 for setting the operation of the apparatus on the first or on the second reel, as well as two erasing circuits comprising AND gates 10, 10', which circuits end at the memories 3 and 3', respectively.
The new apparatus can easily be set to operate in the case of strips of material to be divided up into cuttings of a length l' that differs from l since it is structurally independent of the dimensions of the cuttings S. Besides suitably regulating the cutting frequency of the main cutting device C1-C2, all that has to be done to achieve this is to vary the initial conditions of the auxiliary cutting devices c1-c2 (c1'-c2') and correspondingly to displace the position Y' (Y), that is to say, the position in which the free end of the material N2 (N1) is fastened.
It should be noted that in the particular form of embodiment described above for the apparatus according to the invention, the same signal generated cyclically by the cam 2 is used both for operating the auxiliary cutting systems c1-c2 and c1'-c2' and for the auxiliary infeed systems r1-r2 and r1'-r2'.
The choice of a different signal for the operation of the said infeed systems generated, for example, by the rotation of a second cam keyed to the same spindle on which the cam 2 is mounted but at a different angle thereto can allow the free end of the material on the reserve reel to be in a fixed position, that is to say, in a position Y' (Y) independent of the dimensions of the cuttings S.
In a second form of embodiment for the apparatus according to the invention, a single cutting device is envisaged and this is located at the point where the tracks from the two reels converge.
Under normal operating conditions the said cutting device performs the operations carried out by the previously examined device C1-C2 but when the reel B1 comes to an end, it receives from the usual sensor device instructions to cut the final piece of the material N1 and thus on this occasion does what is done in the main form of embodiment by the device c1-c2.
The free end of the material N2 pushed by means operated in identical ways to those already seen will follow on after the final extremity of the material N1 through the said cutting device so that there is an unbroken sequence of cuttings.
A third form of embodiment for the apparatus according to the invention (see FIG. 3) envisages two cutting devices C1-C2, one placed along the track from the reel B1 and the other along the track from the reel B2, that is to say, it envisages the presence of cuttings S preformed prior to the point where the two tracks converge. The means r1-r2 attend to the unwinding of the material from the reel B1 whilst the respective cutting device C1-C2 divides the material N1 up into cuttings S which are supplied by transfer means that move forward in an intermittent fashion to the main track, which also moves intermittently, at a speed to suit the speed at which they are used up by the wrapping machine.
When the reel B1 comes to an end, the sensor device F1 signals instructions to the device C1-C2 to cut the final piece of the reel B1. Signals are sent by the said sensor device, timed to suit the operation of the corresponding units belonging to the reel B1, to set the rollers r1'-r2' in motion so as to unwind a reserve reel B2, to the cutting device C1-C2 and to the means for moving the track of the reel B2.
The operation of the aforementioned means whose operating characteristics are the same as those used for the reel B1 is such that, in conformity with what has also been seen for the previous forms of embodiment, the final piece cut off the reel B1 is followed at the entrance to the main infeed track by the first piece cut off the reel B2, without there being any superposition and in such a way as to guarantee the infeed continuity to the wrapping machine.
An operating condition for this third form of embodiment as briefly described above and illustrated in FIG. 3 is for the cutting devices to be arranged along the auxiliary tracks at the same number of cycles or steps from the point where the said auxiliary tracks converge.
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An apparatus for producing a continuous succession of pieces or sheets, particularly suitable for infeeding cut pieces of wrapping material to wrapping machines, comprises a track for collating and sending forward the said sheets or cuttings; a plurality of auxiliary tracks leading to the said collation track; means for channelling along the auxiliary tracks, successively, wrapping material from respective reels; and control means for rhythmically cutting such material and for automatically feeding material, end to end, from a fresh reel on exhaustion of an empty reel. The control means comprise sensor means for detecting the end of the material from the empty reel; for cutting from the end portion a piece of material equal in length to or a multiple of the length of the said sheets or cuttings and for thereupon causing material to move forward along another of the said auxiliary tracks so that there is a continuous succession of sheets or cuttings along the above mentioned track where the said sheets or cuttings are collated and sent forward.
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DEDICATORY CLAUSE
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalties thereon.
BACKGROUND OF THE INVENTION
Conversation in a room with large glass windows causes the windows to vibrate in resonance with the conversation. It is said that radar and other listening devices have reached a developmental level from which they can detect the window vibrations and translate them to spoken words. This obviously presents a security problem of major magnitude. In view of these conditions, there is a need for a device which will prevent conversations from being picked up from vibrating windows in order to prevent any possible security leaks.
Therefore, it is an object of this invention to provide a sonic transducer which imparts vibration to a window or glass partition to prevent one from being able to pick up conversations from vibration of the windows or glass partitions.
Another object of this invention is to prevent the capture of conversation from a glass or window by placing an interfering vibration on the glass or window.
Other objects and advantages of this invention will be obvious to those skilled in this art.
SUMMARY OF THE INVENTION
In accordance with this invention, sonic transducer devices are provided that include either a window pane closure as a portion thereof or means for connection to a window pane to vibrate the window pane at such a frequency as to prevent one from being able to monitor the vibration movement of the pane and translate from the vibration the spoken words that are being spoken within a room.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view of a sonic transducer device in accordance with this invention,
FIG. 2 is a schematic view of another transducer device in accordance with this invention,
FIG. 3 is a schematic illustration of a magento-strictive device that can be used in the transducer device of FIG. 2,
FIG. 4 is a schematic illustration of a piezoelectric transducer that can be used in the transducer device of FIG. 2,
FIG. 5 is a schematic view of still another transducer device in accordance with this invention, and
FIG. 6 is an electromagnetic device that can be used in the arrangement of FIG. 5 to impart vibration to a window pane.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Several embodiments of a transducer device are disclosed which place and maintain a sonic vibration in sheet glass commonly used for windows and partitions. This sonic vibration is music, singing, speech and/or noise. The sonic vibration generally is of an energy level (magnitude) slightly exceeding the vibrations induced by conversations, music, tape players, sound movies, etc. in the immediate surrounding areas.
Referring now to FIG. 1, in this configuration the sonic transducer device includes a broad band amplifier 10 which operates from about 50 to about 20,000 cycles per second and has a signal conditioner capable of driving an electrostatic device of the particular window size that is to be vibrated. Broad band audio amplifier 10 has its own built-in power supply that is fed by either direct current or by an ac line. Broad band audio amplifier 10 has an input 12 which is designed to receive an AM-FM radio, noise source, or tape recorder source for the broad band amplifier to amplify and produce output signals at leads 14. Leads 14 are conductively attached in a conventional manner at 17 and 18 such as by conductive adhesive to two electrically conductive glass sheets 20 and 22. Glass sheets 20 and 22 have an elastic, insulative layer 24 therebetween and sheets 20 and 22 are mounted with an insulated housing 26 therearound for supporting glass sheets 20 and 22 with the elastic, insulative layer 24 therebetween.
When the appropriate signal is applied at input 12 to broad band amplifier 10, an output is produced at leads 14 and applied to glass sheets 20 and 22 to induce vibration in sheets 20 and 22 with a magnitude greater than the magnitude with which these sheets vibrate from the human voice in the immediate surroundings. With these interfering vibrations on sheets 20 and 22, efficient interference is produced. That is, sufficient vibration interference is placed on glass sheets 20 and 22 to prevent the translation of the spoken word from being detected and picked off due to vibrations of sheets 20 and 22. An incidental advantage of this embodiment is appreciated due to the window being thermally insulated beyond the normal window pane. That is, elastic and thermal insulation 24 produces the additional advantage of a window of this type as opposed to a single window pane or sheet.
Referring now to FIGS. 2 through 4, other arrangements are disclosed which include a broad band amplifier 10 which is the same or similar to that disclosed in FIG. 1 which has an input 12 with a signal from a noise generator the signal being the same or equivalent to those disclosed for that of FIG. 1. Broad band amplifier 10 has leads 14 at the output thereof that are connected to leads 16 which are connected for driving one or more transducers 30 which are connected to window pane 32 and frame 34 in which pane 32 is mounted. As illustrated, pane 32 has four transducers 30. The number of transducers 30 used to vibrate window pane 32 will depend upon the particular size of window pane 32. As illustrated, there is a transducer 30 at each corner that is used to produce an interfering vibration on window pane 32. Transducer 30 can take a form as illustrated in FIG. 3 and include a magneto-strictive device having an armature 36 attached in a conventional manner such as by adhesive to window pane 32 and with a coil 38 supported by support structure 40 which interconnects the transducer to window frame 34. Coil 38 is connected with leads 16 for driving the transducer. In FIG. 4 a similar transducer is disclosed that includes piezoelectric material 42 that has electrical contacts 44 and 46 are connected to leads 16. Electrical contacts 44 and 46 are connected to window pane 32 and support structure 40 by being bonded or otherwise secured in a conventional manner.
In each of these arrangements, when an input is presented at 12 to broad band amplifier 10, an output is presented at leads 14 and 16 and applied to transducer or transducers 30 to drive the transducer and cause window pane 32 to vibrate. With a transducer as illustrated in FIG. 3, the potential across coil 38 causes the magneto-strictive device to impart vibrating movement to pane 32 and in the piezoelectric device of FIG. 4, application of the potential across leads 16 and piezoelectric material 42 causes window pane 32 to vibrate as piezoelectric material 42 vibrates. Therefore, it can be seen that interfering vibrations are placed on window pane 32 to prevent desired intelligence from being taken from the vibrating window pane. In each of these arrangements, the output produced at leads 14 is properly matched to the characteristics of the particular transducer and the size of the window pane to which the transducer is attached.
Referring now to FIGS. 5 and 6, another sonic transducer device is disclosed which include an input 12 which is similar or the same as that disclosed for FIG. 1 that is input to a broad band amplifier 10 with leads 14 that are connected to coil 52 (see FIG. 6) of electromagnetic transducer 50. Electromagnetic transducer 50 includes permanent magnet 54, armature 56 about which coil 52 is mounted and flexible mount 58 which interconnects armature 56 to mounting means 60 that is secured to permanent magnet 54. Armature 56 has an endface 62 that is adapted to be placed against one surface of window pane 64. If desired, face 62 can be cemented to glass 64 to make a more permanent installation. Support 60 also includes arms 66 that have adjustable joints 68 and outer arms 70 with base supports 72 for securing the transducer to window frame 74. Window pane 64 is mounted in frame 74 in a conventional manner. As can be seen, in this arrangement the device can be used as a portable device for outfitting a room for a particular conference for a limited period of time or it can be installed as a permanent installation to a conventional window frame with a conventional window pane therein. Therefore, it can be seen that an ordinary window with a regular frame and glass therein can be converted to a sonic secured window by using the device disclosed in FIGS. 5 and 6. It is also pointed out that cementing of face 62 to window pane 64 provides a slight performance improvement over just placing face 62 in contact with window pane 64.
In operation, with the sonic transducer mounted in a window and with face 62 against window pane 64, application of the desired signal to input 12 of broad band amplifier 10 causes the desired signal to be produced at leads 14 and applied to coil 52 to cause armature 56 to move relative to permanent magnet 54 in accordance with the signal applied across coil 52 and thereby cause window pane 64 to vibrate and place an interfering vibration on window pane 64 to prevent one from being able to pick up conversations being conducted in a room to which window pane 64 is a portion thereof. Therefore, it can be seen that this device also enables one to safe a room from conversation being pickedoff at a window thereof.
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A sonic transducer device for vibrating windows and glass partitions in theuman ear sensitivity range to prevent the capture of conversation by placing an interfering vibration on the windows or glass partitions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to memory circuits, and more specifically, to a memory circuit system and architecture for significantly reducing power consumption during stand-by or sleep mode of operation.
2. Discussion of the Prior Art
Negative Word-line (Vwl) generators are used in today's integrated circuit semiconductor memory chips in order to hold all non-selected word-lines of memory array at a negative potential. The purpose is to reduce cell leakage and improve the retention time. During stand-by, or sleep mode, voltage generators consume energy. One proposal in the art, as described in the reference to D. Takashima, Y. Oowaki et al. entitled “A Novel Power-Off Mode for a Battery-Backup DRAM”, Symposium on VLSI Circuits Digest of Technical Papers , 1995, pp. 109-110, is to completely turn this Vwl power off. However, this approach has a disadvantage since the system would take a long period of time, e.g., in the range of 10 μs, to return back to the active mode, or prior to conducting a refresh. This may not be practical, when the eDRAM memory is used and periodical refresh is required. An intuitive approach is to use a lower-power standby pump other than the active pump. Whenever the chip enters the low-power mode, the active pump components are shut off, and only the stand-by pumps remain on to keep the voltage level. This approach however, also has some disadvantages, for example, extra hardware are needed to be built on the expensive chip real estate. These standby pumps are normally weak and not efficient, or less useful during the active mode operation. Besides, these stand-by pumps still consume energy during the low-power mode.
Further, array body bias voltage (Vbb) generators are used in today's memory chips to supply a voltage for biasing the substrate body in which the active devices are formed. That is, this Vbb voltage is applied to the body of the transfer device of the DRAM array. Vbb is used to block the device sub-threshold leakage by boosting device threshold voltage.
As shown in FIG. 1, each generator 10 , Vwl or Vbb, comprises a limiter circuit 12 and an oscillator circuit 15 for generating clock pulse for powering a charge pump circuit 18 . The charge pump of each respective generator will then pump the output level 19 of each generator from a first level to a second level. The limiter device 12 is provided to detect whether the output voltage 19 has reached to the targeted second level or not. If it does, then the limiter device 12 will shut off the pump and stop pump operation. Inside each pumps there are at least two boost capacitors (not shown). For example, in a two-stage pump, then about 4 to 6 boost capacitors are presented. These boost caps are used to assist charge pumping. Details of operation are well known to skilled artisans. A decoupling capacitor is also provided for the Vwl generator which is a capacitor connected to its output bus. For example, a 3 nF to 20 nF of decoupling capacitor may be needed for Vwl bus of a DRAM with varying density. It should be understood that the Vbb is the p-WeLL bias voltage, and is already tied to a huge pWell of the DRAM array, therefore, no decoupling capacitor is needed. The decouple capacitor is used to stabilize the output voltage 19 and avoid any coupling effect by other voltage levels.
It would be highly desirable to provide an improved low-power semiconductor memory chip voltage generator design that provides for the switched connection of individual Vbb and Vwl (or Vneg) generators and, the simultaneous turning on of these generators when connected during a power-on operation in order to speed the power on process.
It would additionally be highly desirable to provide an improved, low-power semiconductor memory chip voltage generator design that additionally provides for the separation of switch connected individual Vbb and Vwl (or vneg) generators to avoid any cross-over noise and permit different voltage level outputs during an active mode of operation.
It would additionally be highly desirable to provide an improved low-power semiconductor memory chip voltage generator design that provides for the switched connection of Vbb and Vwl (or Vneg) busses, with the Vwl generator being turned off to save energy during the sleep mode of operation, and obviating the need for a stand-by negative word-line (Vwl) generator system.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved low-power semiconductor memory chip voltage generator system that provides for the switched connection of individual Vbb and Vwl (or Vneg) generators and, the simultaneous turning on of these generators when connected during a power-on operation in order to speed the power on process.
It is a further object of the present invention to provide an improved, low-power semiconductor memory chip voltage generator system that additionally provides for the separation of switch connected individual Vbb and Vwl (or Vneg) generators to avoid any cross-over noise and permit different voltage level outputs during an active mode of operation.
It is another object of the present invention to provide an improved low-power semiconductor memory chip voltage generator system that provides for the switched connection of Vbb and Vwl (or Vneg) busses, with the Vwl generator being turned off to save energy during the sleep mode of operation.
It is yet another object of the present invention to provide a low-power voltage supply system for a memory chip device having a relaxed (or longer) sleep refresh duration time so that the energy required during the sleep/refresh may be easily supplied by a Vbb generator pump without causing any disturbance on the array substrate.
According to the invention, there is provided a low-power voltage supply system and method for a memory device comprising a semiconductor substrate array of memory cells, wherein the system comprises: a negative word-line (Vwl) generator device for supplying first (word-line) voltage at an output thereof for selecting memory cells in a memory device; an array body bias voltage (Vbb) generator device for supplying second (back bias) voltage at an output thereof for biasing the substrate array in a memory device; and, a switch device for selectively connecting the negative word-line (Vwl) generator device output to the body bias voltage (Vbb) generator device output during one or more operating states of the memory device.
Preferably, during a power-on operative state for turning on the generator devices, the switch device couples the negative word-line (Vwl) generator device output to the body bias voltage (Vbb) generator device output in order to speed up the power-on process for the memory device.
Additionally, the low-power voltage supply system of the invention provides for the turning off of the negative word-line generator during a sleep/low-power mode of operation, with the switch shorting the negative word-line power supply to the substrate bias (or Vbb) voltage supply which is constantly supported by the Vbb generators. During the low-power mode, although the chip temperature may drop, the memory chip would still consume some energy. For example, the negative word-line level (or Vneg) may drift higher if leakage exists, or a refresh cycle is needed. Therefore, it may not be left floating, or otherwise, the cells may leak if the Vneg becomes less and less negative. On the other hand, the substrate bias (or Vbb) generator is normally left on after the chip is powered on. The voltage level may or may not be identical to the negative word-line level. The Vbb level is determined by the optimum condition in which the cells have lowest leakage level. If Vbb is too high (or less negative), then the sub-threshold leakage level may be poor. But, if Vbb is too low (or more negative), the device junction leakage level will dominate. Nevertheless, the Vbb level is usually tracking with the Vneg level, and most of time their values are identical. Thus, in the active mode, the Vbb and Vneg supplies are separated, so as to avoid any cross-over noise between them. In the active mode, the wordlines may be accessed at a high frequency. As a result, the Vneg level is noisy or fluctuated. If both levels are shorted all the time, the Vbb level will also become noisy which could cause data loss or other unexpected and undesirable effects. This problem is obviated in the sleep mode, since no array activity other than occasional refresh is expected.
Implementation of the low-power voltage generation system and method of the invention are advantageous in that: (1) No extra hardware, e.g. no standby Vneg pumps are needed, which means smaller chip area; (2) A power saving in because Vneg is completely shut off resulting in no (zero) Vneg stand-by energy consumed; (3) No cross-over noise between Vbb and Vneg during the active operating mode since they are isolated, which means less noise; and (4) Design flexibility in that Vbb and Vneg level are enabled to be set slightly different. Furthermore, the principles and advantages of the invention may be applied to any two or more DC generator systems, negative or positive.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, aspects and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
FIG. 1 depicts a typical Vwl and Vbb voltage generator circuit design.
FIG. 2 is a conceptual block diagram depicting the improved low-power semiconductor memory chip voltage generator system including a low-power negative word-line (Vwl or Vneg) generator having different operating states according to the principles of the invention.
FIG. 3 ( a ) is a detailed block diagram illustrating the implementation of the improved low-power semiconductor memory chip voltage generator system implemented for a memory device.
FIG. 3 ( b ) is a detailed block diagram illustrating the switch circuit for connecting the Vbb and Vwl power supply generators according to the present invention.
FIG. 4 ( a ) is a diagram illustrating the Vbb/Vwl output voltage waveforms during an example simulation of the power-on mode.
FIG. 4 ( b ) is a timing diagram of signals utilized during power on operation resulting in the simulation result waveforms of FIG. 4 ( a ).
FIG. 5 ( a ) is a diagram illustrating the Vwl output voltage waveform during an example simulation of the active mode.
FIG. 5 ( b ) is a timing diagram of signals utilized during active mode operation resulting in the simulation result waveform of FIG. 5 ( a ).
FIG. 6 ( a ) is a diagram illustrating Vbb/Vwl voltage waveforms during an example simulation of the sleep and refresh modes.
FIG. 6 ( b ) is a timing diagram of signals utilized during sleep and refresh modes resulting in the simulation result waveforms of FIG. 6 ( a ).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Conceptually, as illustrated in FIG. 2 the improved low-power semiconductor memory chip voltage generator system 20 comprises a negative word-line low Vwll voltage generator 28 and an array body bias voltage Vbb generator 26 that are designed such that: 1) during a power-on operation 18 a , a switch 50 operates to short the Vbb and Vwl (or Vneg) generators 26 , 28 with the design enabling their simultaneous turn-on in order to speed the power on process; 2) during an active mode of operation 18 b , the switch 50 opens so that Vbb and Vwl (or Vneg) generators 26 , 28 separate in order to avoid any cross-over noise and allow different voltage levels during the active mode; and, 3) during a sleep mode of operation 18 c , the Vbb and Vwl (or Vneg) power supply busses are connected, however, with the Vwl generator 28 being turned off in order to save energy. Each of these circuit configurations corresponding to the three modes of operation will be described in greater detail herein. Thus, as described herein, two negative pumps with similar output voltage levels can be integrated for power saving purposes. However, it is understood that, according to the principles of the invention, two or more DC generator systems, negative or positive, may be integrated to save power or, improve performance by sharing hardware.
FIGS. 3 ( a ) and 3 ( b ) illustrate the implementation of the low-power semiconductor memory chip voltage generator system 20 applied for a DRAM macro 90 comprising a decoder/driver circuitry 92 for driving a memory cell array 94 . As shown in FIG. 3 ( a ), the Vwl generator 28 includes output bus 38 carrying voltage to power a memory word-line driver 93 for providing a negative voltage for all the unselected word-line voltages 88 for each memory cell 95 . Likewise, bit line drivers (not shown) are provided for selecting a bit-line 89 of a memory cell 95 . The Vbb generator 26 includes output bus 36 carrying a back-bias voltage for each memory cell 95 as shown in FIG. 3 ( a ). As further shown in FIG. 3 ( a ), the output busses 36 and 38 are connected to a switch device 50 which provides the output bus coupling in accordance with the preferred embodiment of the invention as will be explained in greater detail herein.
The switch circuit schematic is illustrated in FIG. 3 ( b ). The switch 50 itself is formed by a nMOS transistor device 45 having source and drain terminals directly connected to Vbb output bus 36 and Vwl output bus 38 for the respective Vbb and Vwl generators. Preferably, the nMOS transistor is a large width device having a channel length of 0.36 μm, for example. The gate 46 of the nMOS transistor is controlled by a logic circuit 47 comprising NAND, NOR and inverter gates which receive various inputs for controlling switching state of the device. The input signals to determine the switching state include:
(1) PWRON—the power on signal 41 , i.e., during chip power on period (e.g., PWRON=0), to turn on all of the DC generators sequentially and in a specific order in order to avoid any latch-up situation. The PWRON signal is triggered (e.g., PWRON=1) when the power-on sequence is finished, i.e., when the power-on operation is done, the chip is ready for active mode operation. As described, the system of the invention advantageously exploits the strong Vwl pump during power on period to bring both VBB and VWL levels up quickly. In this case, when PWRON=0 during power on period, the gate of the switch must be turned on. On the other hand, when the power on is finished, the switch is opened to effectively isolate the Vbb bus and Vwl bus so that normal operation may take place and the occurrence of cross-noise between Vwl and Vbb being prevented.
(2) VWLLMT—the negative wordline limiter signal 42 . The Vwl (negative wordline) generator has a limiter which limiter indicates whether the VWL generator is active or not. For example, when the Vwl level is reached, the pump is shut off, so that it will not overpump the system. Therefore, VWLLMT=0 means the level has reached, and pump should be stopped, otherwise, the pump will continue to bring the voltage level up. By the combination of PWRON=0, an VWLLMT=1, the input to the NOR gate 48 will be high, which continue to force the switch on. When the VWL level is reached, the switch 50 will be off (transistor 45 turned off), at this moment, the Vwl level will be idled, since its pump is off, but the Vbb level continue to be active and supported by the Vbb pump. The reason is Vbb comprises a huge capacitor which requires a little longer time than Vwl network to be fully charged up. Thus, the switch is disengaged when the Vwl level is reached, i.e., VWLLMT=0. This arrangement may be used for pumping two different voltage levels, when the first level is reached one pump is off, and the other pump continues to pump to the second level.
(3) SLEEP—the signal 43 for indicating that the sleep mode is on. At this point, irregardless of the PWRON and VWLLMT signals, the switch 50 is forced on when SLEEP=1. At this moment, the Vwl pumps are completely disable to save power, since the generator is no longer in active operation. Further, the Vwl network is supported by the weak Vbb pump. During sleep, the Vwl may need charge replenish, since leakage still occur. This arrangement will save a standby Vwl pump.
With respect to a conventional memory device power-on sequence, the Vbb generator is switched on with a high speed oscillator. The Vbb generator pump does not stop until Vbb level reaches to its target level. Then, a Vpp voltage (not shown) is turned on. After Vpp reaches about 1V volts, the Vwl generators are turned on. This conventional sequence is arranged in such a way to avoid any detrimental effect, such as to avoid forward biasing a device's junction and cause circuits to latch-up. However, it is known that the Vbb voltage ramp up time is relatively long, in the range of 50 μs. It is not only because Vbb pumps are weak, but also Vbb level is coupled up by Vpl (memory cell plate voltage), since plate voltage supply is ramped up simultaneously. It is the case that a DC generator design between eDRAM and stand-alone DRAM are somewhat different. For example, in the eDRAM design, the Vpl is tied to ground, therefore, the Vbb coupling-up effect does not exist. The Vbb parasitic capacitance is also not very big since the macro size is relatively small (e.g., 4 Mb or 8 Mb).
According to the invention, however, in the power-on mode 18 a , the Vbb and Vwl voltages are merged together during power-on in order to shorten the power-on process. In order to do that, the Vpp must also ramp up simultaneously to about 1V. This is because, all the p-wells tied to Vwl are isolated by n-wells which are tied to Vpp. It is safe that Vpp be powered up to certain positive voltage level while ramping up the Vwl. During power-on, since Vwl and Vbb are shorted to each other, one of each pump are turned on. The Vwl and Vbb pumps are designed differently, for example, the former has a bigger reservoir capacitor (e.g., four times bigger) and powered by a faster oscillating speed (35.5 MHz vs. 7.75 MHz, for example). Similar to that of the Vpp, Vwl has a high-speed limiter. The Vbb's limiter is intentionally designed to operate with a slow speed to save energy and thus its response time is in the range of 1000 ns. The capacity of a Vbb pump is about 0.2 mA, but for a Vwl pump is more than 2.1 mA. The pump circuit for both Vbb and Vwl are basically the same, the pumping efficiency is in the range of 75% for both. The switch used to short Vbb and Vwl supplies is activated during the power-on period until Vwl level is reached. Additionally, during sleep mode, the switch 50 is always on so that Vwl supply is from Vbb.
Example Vbb/Vwl waveforms during an example system power-on simulation are shown in FIGS. 4 ( a ) and 4 ( b ). Specifically, FIG. 4 ( a ) illustrates the nearly identical ramp-up times for the Vbb bus voltage output 36 and Vwl bus voltage output 38 in accordance with the present invention. FIG. 4 ( b ) is a timing diagram depicting the signals utilized during power on operation resulting in the simulation result waveforms of FIG. 4 ( a ). It is understood that during power-on, the Vbb and Vwl are joined only when Vwl is below a target limit. As shown in FIG. 4 ( b ), it takes less than 1.1 μs for Vwl to reach that target voltage level 60 , as depicted FIG. 4 ( a ), for example. At that point, the VWLLMT signal 42 in FIG. 4 ( b ), triggers, and the switch device 46 is opened to isolate the Vwl and Vbb generators. As shown in FIG. 4 ( b ), an oscillator signal 42 ′ is input to the Vwl charge pump of the Vwl generator during the power on-sequence, i.e., when VWLLMT 42 is active. Additionally, depicted in FIG. 4 ( b ) is the VBBLMT signal 44 for the Vbb generator and its corresponding oscillator signal 44 ′ for the Vbb generator charge pump which becomes active during the power-on sequence after the Vwl generator pump. As shown, the oscillator signal 44 ′ for the Vbb generator is a much lower frequency than the corresponding oscillator 42 ′ for the Vwl pump. The Vbb and Vwl supplies are intentionally made leaky in the example simulation to mimic a potential real-life situation. In this example simulation, the Vbb final level being simulated is at −0.56V, while Vwl is at −0.48V, although both targets are set at −0.5V. The Vbb is slower due to the weakness of the Vbb charge pump and its larger capacitive load.
That is, as explained earlier, Vbb and Vwll are saturated at different levels due to different limiter speeds. Thus, as shown in FIG. 4 ( a ), some overshooting on the Vbb level may be desirable. Generally, it may take longer time to charge up resistive Vbb capacitors than as shown in the simulation depicted in FIG. 4 ( a ). The amount of Vbb overshooting depends on: 1) the speed of limiter; 2) the differential amplifier response time; and 3) on the driver chain delay. The reason there is a long driver chain with loaded capacitors for a Vbb limiter is to remove the glitches so that the Vbb limiter signal will be free of noise. An example total time delay computed by adding up herein mentioned items 1, 2 and 3 is about (276 ns+407 ns+487 ns) 1170 ns. The amount of Vbb overshooting is also determined by the Vbb pumping rate and Vbb loading. For a single Vbb pump to turn on with an oscillating frequency of 7.5 MHz, the pumping rate is about 36 uV/ns. This will result in Vbb level to be saturated at about −0.56V. Overshooting of Vbb may have an advantage for the joint Vbb/Vwl approach. During the sleep mode when Vwl pumps are completely shut off, by merging Vwl to Vbb, the Vwl level may also become slightly lower and this may sustain a few refresh cycles without requiring Vbb pump to turn on.
During the active mode of operation 18 b , Vbb and Vwl are separated with each generator being activated separately. FIGS. 4 ( a ) and 4 ( b ) illustrate the simulation results given a 20 ns word-line (WL) cycle time operation. The estimated Ipp current needed for the macro during this period is 0.81 mA. For example, 3 WLs are on simultaneously, with a total load of 1.5 pF and a voltage swing of 3.6V (from −0.5V to 3.1V). It is assumed that the major portion of current from Vpp will be drained by Vwl supply. During this period, one Vwll pump is always on, the other three pumps will be automatically turned on based upon need. The Vwl pumps are operated at a speed of 35.5 MHz. The capacity of one Vpp pump is about 2.1 mA. Therefore, four (4) pumps are more than sufficient to drain 2 mA Ipp peak current. In the active mode, the capacity of Vwl pump is not a problem, but Vpp pump system is rather weak due to poor pumping efficiency caused by low Vdd (1.8V) supply. To keep Vwl swing within +/−5%, a large de-cap is needed. For example, a 2.4 nF capacitive load may be used. Unlike Vbb, Vwl has a high-speed limiter similar to that of Vpp. This is why the fluctuation range of Vwl is much tighter than that of Vbb.
Example Vwl waveforms during an example active system mode simulation are shown in FIGS. 5 ( a ) and 5 ( b ). In the active mode, as shown in FIG. 5 ( b ), the VPWRON signal 41 is high (=1). In the example simulation, there is continuous pulse word-line (array) activation as indicated by row/address activation (RAS) signal 49 and the Vwl generator is the means by which these RAS signals are sourced. The Vwl generator additionally functions as a sink for the corresponding Vpp current as represented by the IJVWL signal 49 ′ or word-line swing signals. Thus, during active mode, due to the current drawn during the drawn from the continuous array activation, the Vwl charge pumps are activated in response to activation 61 of the VWLLMT signal 42 as shown in FIG. 5 ( b ). Corresponding to the activation of the VWLLMT signal 42 , the oscillator signal 62 is active for the pumping up the Vwl voltage. As shown in FIG. 5 ( a ), in response to VWLLMT signal 42 activation 61 , the Vwl starts increasing (more negative) at 63 . Although in the example simulation the Vwl output bus is tied to a decoupling capacitor of 2.4 nF, the Vwl voltage 38 exhibits ringing which fluctuates at about −0.5+/−10%. It is understood that, for some circuit designs, this may be acceptable.
Example Vbb/Vwl waveforms during an example system sleep mode simulation are shown in FIGS. 6 ( a ) and 6 ( b ). Specifically, during the sleep mode, the VSLEEP signal 43 is active (=1) to turn on the switch device 50 . However, as shown in FIG. 6 ( a ), only the Vbb voltage output 36 is available as the Vwl generator is turned off. The Vwl 38 and Vbb 36 levels are disjoined again at a time indicated at 64 by the switch device 50 in response to the VSLEEP signal 43 being turned off. As shown in FIG. 6 ( b ), however, during active mode, the Vwl pumps are switched on to meet the high capacity requirement. That is, VLLMT signal 42 and corresponding oscillator signals 42 ′ are turned on in order to maintain the Vwl voltage at its target level.
During sleep mode of operation 18 c , the Vwl generator is completely shut off to save Vwl standby power of about 156 uA. To achieve this, the Vwl busses are shorted to those of the Vbb. Therefore, Vbb generator will have to provide current to sustain not only Vbb leakage, but also the refresh current from Vwll. The refresh pulse duration is targeted at 100 ns. Therefore, the average current required during refresh is about 0.2 mA, and on e Vbb pump is sufficient. The Vbb limiter 44 will kick the Vbb pump on when Vbb level reaches −0.48V. The average pumping rate for a single VBB pump is about 40 uV/ns. According to one estimation, the maximum refresh cycle time in the sleep mode at 40 degree C is about 1500 ns. In the example simulation depicted, a 1000 ns cycle is used. It is estimated, due to high Vbb pumping efficiency, during the sleep mode, one Vbb pump is sufficient to keep both Vbb and Vwll level. In the waveform shown in FIG. 6 ( a ), the sleep mode starts at 10 ns and ends at 3000 ns. At this moment, only Vbb oscillator 44 ′ is on. However, when the sleep mode is over, the Vbb and Vwl are separated, and Vbb is pumped down continuously to −0.57V due to the aforementioned delay. The Vbb level fluctuates between −0.47V and −0.57V. However, the Vwl due to its faster response speed has a fluctuation range of about −0.48V to −0.5V. During active mode, if the current demand is low then only one Vwl pump is on, or otherwise, four pumps may be on simultaneously.
An estimation of the coupling noise from bit lines to the wordline low level (or Vwl) is now provided using an existing eDRAM macro as an example:
(1) Assuming one-half (½) Vdd sensing, when one word-line of 1M array macro is selected. The worst case of coupling is when all the cells are stored with logic “zero” and are read from the cells of that wordline. So, one BL of each pair will swing from 0V to 180 mV, and the other BL stays at ½ Vdd. Therefore, total of 2048 BLs will swing from 0V to 180 mV within an approximate 2 nano-second signal development time period.
(2) These 2048 BLs will couple 512 (actually 511) of non-selected WLs up. The BL to passive WL coupling capacitance for each cell is about 0.065 nF, each 1M array has 512 WLs and 2048 pairs of Bls, therefore the total coupling capacitance 0.062 nF×2048×512=0.065nF approximately. The reason that 512 cells are used is to assume the worst case. That is, wire BL to wire WL coupling is the same as the coupling through device.
(3) The Vwl decoupling comprises not only the decoupling capacitor which is about 1.5 nF, but also the wordlines from each four macros that connect to the WLL busses. The total wordline capacitance of a macro is estimated as 0.206 fF/cell×2048×512=0.216 nF.
(4) The Vwl coupling noise may be estimated as 180 mV×(0.065 nF)/(0.065 nF+4×0.216 nF+1.5 nF).
Normally, if the cycle time is fast, for example 20 ns, then what is coupled up will be coupled down. The Vwll generators will not be able to response at this speed. However, in the active mode, when operating a long WL cycle, i.e., page mode operation, the four active Vwl low generators will bring the voltage to the target level before the WLL level gets coupled down. In the sleep mode, during the long refresh period (e.g. 200 nS), the Vbb pump is not able to bring the Vwl level down after it is coupled up. However, since Vwl is merged to Vbb, the enlarged decoupling capacitance may further reduce the noise to only about 24 mV. Eventually, the Vwl level will be restored when all the BLs return to ground. The VWL generators preferably have sufficient power to overcome the coupling and keep cell leakage current low.
With the low-power word line low generator design in accordance with present invention, the Vbb and Vwl generator standby power from is reduced approximately from about 186 uA to about 10 uA. This is a significant energy saving especially for battery-supported (i.e., handheld) embedded applications. Moreover, there is virtually no waiting time required to get system back to normal active mode.
While the invention has been particularly shown and described with respect to illustrative and preformed embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention which should be limited only by the scope of the appended claims. Thus, while the invention is described herein is directed to shared Vbb and Vwl shared negative voltage pump system voltages for DRAM memory circuits in order to boost performance, reduce power and avoid possible noise coupling effect, the same concept may be applied to any other two or more pump systems.
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A system and method for considerable reduction of power consumption in memory circuits implementing Vbb (array body bias) and Vwl (negative word line) voltage generators. The system comprises switching off the negative WL generator during sleep or standby mode, so that no power is consumed. A relaxed refresh operation is carried out and the negative WL is powered by the Vbb generator. The noise coupled to the negative WL supply from BL swing is reduced due to the joint Vbb-Vwl decoupling scheme. In the active mode, the Vbb and Vneg are separated to avoid any cross-over noise and to maintain design flexibility. During power-on period, the ramp-up rate of Vbb level is improved by the Vwl generator. The advantages may be summarized as: (1) simpler Vbb generator design, (2) much smaller Vbb generator size, (3) reduced Vbb power, (4) no stand-by current from Vwl generator, (5) low decoupling noise for Vwl level during stand-by or sleep mode, (6) enhanced ramp-up rate for Vbb during power-on, (7) no cross-over noise between Vbb and Vwl during active mode, and (8) design flexibility of Vbb and Vwl in the active mode. The principles and advantages of the invention may be applied to any two or more DC generator systems, negative or positive.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to nail polish drying, and more specifically, to a novel method and product for drying nail polish in sixty seconds.
2. Discussion of the Prior Art
A large number of methods and compositions for beautifying and strengthening the nails of humans are well known. Prior art methods include coating the nail of an animal, including humans, with a composition including a film-forming polymer and additional ingredients such as pigment, plasticizer, and solvents, or alternatively, attaching preformed artificial nails to human nails with adhesives. Additional methods include adding cross linkable polymers to nail coating compositions to mend, strengthen and elongate natural nails and repairing nails with a fabric patch.
Most nail compositions presently on the market or disclosed in prior art, dry in five minutes or longer. Even those nail enamels that claim to be quick-dry, i.e., dry in about five minutes, are often not truly dry but rather are only dry to the touch. When a purportedly "dry" nail enamel of the prior art brushes up against a hard surface, the nail enamel often smudges, leaving tack.
One prior art composition for reducing the drying time is shown in U.S. Pat. No. 4,798,720 to Holder. The composition is a mixture of commercially available products, a top coat polish, an acrylic nail powder, an acrylic nail primer, and an adhesive. The top coat polish is a commercial product with a nitrocellulose base. In use, the new composition is applied as a base coat layer, a color polish is coated on top of the first layer, another layer of the new composition is applied over the color polish as a third layer, another coat of color polish is applied over the third layer, and another coat of the new composition is applied over the second color polish as the fifth layer. By using the five step coating sequence, drying times are reduced.
Another composition for reducing the drying time is U.S. Pat. No. 5,130,125 to Martin et al. The composition, for application over a nail polish, consists essentially of cellulose acetate butyrate resin, a mixture of solvents for dissolving the cellulose acetate butyrate resin to form a first solution, a plasticizer for the first solution, and a solvent for the plasticizer, providing a dry, non-tacky, non-brittle solid coat and which is quick drying when applied over a nail polish while wet.
U.S. Pat. No. 5,093,108 to Pappas et al comprises a primary film-forming polymer, a secondary film-forming polymer, at least one plasticizer, at least one thixotropic agent, at least one pigment, and an amount of acetone ranging from about 4.5% to about 35% by weight of said composition in combination with at least one additional solvent having sufficient polarity in combination with acetone to dissolve the primary and secondary film-forming polymers and said plasticizer to produce a stable composition.
U.S. Pat. No. 5,206,011 to Pappas et al discloses a quick-drying composition comprising sufficient quantities of organoclay thixotropic agents having acceptable static viscosities from about 400 to about 1200 centipoises and may accommodate numerous pigments to produce nail enamel compositions exhibiting favorable characteristics.
U.S. Pat. No. 5,275,807 to Pappas et al discloses a quick-drying composition comprising a primary film-forming polymer, a secondary film-forming polymer, e.g., a resin which functions to strengthen the primary film-forming polymer and improve the adhesion and gloss of the nail enamel, a plasticizer, and a solvent system containing a plurality of solvents one of which is acetone in an amount no less than about 4.5% and preferably no less than about 13% by weight of the product.
A composition which can be used to coat a natural or synthetic nail which dries in less than three minutes without requiring an additional application of a base coat or top coat would be very desirable. Nail polishes which dry in a period of less than 150 seconds would be even more desirable, as would polishes that dry in periods less than 90 seconds. A nail polish composition which would dry in a period of no greater than about 60 seconds would be especially useful in situations where "drying" time is important.
Working women need to have a product which can be easily applied and which dries in the shortest amount of time to avoid a situation where they are simply wasting precious time waiting for their nail polish to dry. In the manicure and pedicure industries, a colored nail polish composition which can dry in a period less than three minutes would provide a significant advantage over the prior art compositions.
Traditionally, when one performs a manicure or pedicure, after sufficiently cleaning and drying the nails, a layer of base coat nail polish is applied to the surface of the nail. The base coat polish is typically colorless. Thereafter, coats of colored nail polish are sequentially applied to the nails. Typically, up to three coats of colored polish are applied, and more typically, two coats are applied. Thereafter, a layer of top coat colorless nail polish is applied onto the colored nail polish. This sequence of base coat, colored polish, and top coat polish remains substantially the same, whether the nails are natural or acrylic.
Additionally, although the base coat/colored, polish/top coat, polish procedure is typically used, a long period of time is required for the colored polish to completely dry, typically from at least 15 to 30 minutes, and possibly longer.
Therefore, when an individual is in a hurry, such as a professional business woman, it is impossible to have an adequate amount of time for a manicure or pedicure. This can be particularly detrimental when the business woman is meeting a client or making a presentation and wants her nails to have a manicured look.
In addition, there exists a need for a product which is to be used in connection with colored nail polish to reduce the drying time of the colored polish. Further, there exists a need for reducing the number of chemicals used by cosmetologists when performing manicures.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a nail drying product which can be applied to nail polish on natural and synthetic nails and will dry the nail polish in sixty seconds.
It is a further object of the present invention to provide a general method for applying a nail polish drying product to dry nail polish in sixty seconds after application.
These and other objects of the present invention may be readily determined from the detailed description of the invention which is set forth herein
DETAILED DESCRIPTION OF THE INVENTION
The present invention entails a new and novel use of cotton seed oil. The cotton seed oil of the present invention is refined, bleached and deodorized to a stage that is edible. Cotton seed oil is at present being used as a cooking oil and in the manufacture of margerine. The refining process is as follows: seeds from the cotton plant are pressed into a black, crude oil and the crude oil is then put through a refining process with Diatomaceous Earth and Flux Calcined. To prevent oxidative rancidity, the cotton seed oil is then processed with BHA, Propyl Gallate, Citric Acid and Propylene Glycol. The processed cotton seed oil is now a pale yellow, odorless, edible oil.
We have discovered that an application of the processed cotton seed oil, as described above, will dry a manicure of a base coat, two coats of nail polish, and a top coat in sixty seconds. The process of the present invention consists of waiting one minute after application of the enamel and top coat, and then brushing on a generous amount of the processed cotton seed oil of the present invention. In sixty seconds the nail enamel will be dry.
While not being limited by way of theory, it is believed that the processed cotton seed oil of the present invention is responsible for creating an interaction with the solvents utilized in the nail polish compositions currently available on the market, to substantially reduce the drying times of the nail polish compositions to sixty seconds.
It is obvious from a review of the specifications of the above cited references that the prior art nail polish drying compositions have used many types of volatile matter (solvents), such as for example, Ethyl alcohol, acetone, ethylene glycol monomethyl ether, and ethylene glycol monobutyl ether. In contrast, the present invention uses an edible cotton seed oil which is non-toxic, non-harmful to infants, bio-degradable and easily disposable.
The invention has been described in terms of specific embodiments set forth in detail herein, but it should be understood that these are by way of illustration and the invention is not necessarily limited thereto. Modifications and variations will be apparent from the disclosure and may be resorted to without departing from the spirit of the inventions those of skill in the art will readily understand. Accordingly, such variations and modifications are considered to be within the purview and scope of the invention and the following claims.
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A method for drying nail composition enamel in sixty seconds comprising the application of processed cotton seed oil to nail polish composition on natural and synthetic nails.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates in general to internal combustion engines and more particularly to the internal combustion engines of a direct fuel injection type in which fuel is directly injected into a cavity of the piston in each cylinder to produce an air/fuel mixture and the mixture is ignited by an ignition plug.
[0003] 2. Description of the Related Art
[0004] One of the internal combustion engines of the above-mentioned direct fuel injection type is shown in Laid-open Japanese Patent Application (Tokkaihei) 11-82028, that enables a so-called stratified combustion.
[0005] In the engine disclosed in the publication, each piston has a reentrant type cavity, and a fuel injection valve is arranged just above the cavity so that fuel is injected toward the cavity. That is, atomized fuel injected from the injection valve is forced to collide obliquely against a peripheral wall surface of the cavity to produce a circulation of the atomized fuel that is directed toward a center of the cavity thereby to produce an appropriate stratified air-fuel mixture over the cavity. Ignition of the mixture is effected by an ignition plug that is located beside the fuel injection valve.
SUMMARY OF THE INVENTION
[0006] As is known in the art, in the internal combustion engines of the above-mentioned direct fuel injection type, a penetration force of the atomized fuel from the fuel injection valve exerts a remarkable influence on production of the stratified air-fuel mixture. It is said that such penetration force is based on a real time and generally constant even when the engine speed and engine load are subjected to a change. Thus, if for example the engine speed is increased, it tends to occur that formation of the air-fuel mixture is not made in time. Accordingly, in fact, the operation condition of the engine that enables formation of an appropriate stratified air-fuel mixture is quite limited.
[0007] Accordingly, it is an object of the present invention to provide a direct fuel injection type internal combustion engine that can easily produce an appropriate stratified air-fuel mixture.
[0008] Prior to describing the invention in detail, the present invention will be outlined with the aid of the accompanying drawings.
[0009] In the direct fuel injection type internal combustion engine of the present invention, there are arranged in each cylinder a fuel injection valve that injects fuel against a cavity of a piston to produce an atomized fuel for an air-fuel mixture and an ignition plug that ignites the air-fuel mixture.
[0010] The fuel injection valve has two fuel injection modes, which are, a basic first fuel injection mode wherein the penetration force of the injected fuel sharply increases at an initial stage of the fuel injection and an increasing rate of the penetration force gradually lowers with passage of time and a second fuel injection mode wherein the penetration force sharply increases at a middle stage of the fuel injection, and these two fuel injection modes are switched in accordance with an operation condition of the engine.
[0011] That is, when, for example, a fuel injection pressure is relatively low, the valve takes the first fuel injection mode and when the fuel injection pressure is relatively high, the valve takes the second fuel injection mode. That is, when the engine speed is in a lower range, the fuel injection valve takes the first fuel injection mode with a lower fuel injection pressure, and when the engine speed is in a higher range, the fuel injection valve takes the second fuel injection mode with a higher fuel injection pressure, so that a suitable penetration force characteristic of the atomized fuel from the fuel injection valve is obtained.
[0012] The above description will be much clarified from the following description.
[0013] FIGS. 1A and 1B are respectively a graph and a drawing that are provided for explaining the characteristic of penetration force exhibited by a fuel injection valve employed in the present invention.
[0014] In FIG. 1B , the characteristic of penetration force is evaluated with reference to a longitudinal length of the injected atomized fuel, that is, a length from a fuel injection nozzle of the valve to a leading end of the injected atomized fuel.
[0015] In the graph of FIG. 1A , there is shown the characteristic of penetration force exhibited by a fuel injection valve when the fuel injection pressure is varied. The graph shows a relation between a time elapsed from a start of the fuel injection and the penetration force. The curve denoted by “Pinj=P1” is a characteristic generally exhibited by a swirl type fuel injection valve and a multi-nozzle type fuel injection valve, that are commonly employed in the direct fuel injection internal combustion engine. The curve “Pinj=P1” shows the characteristic of penetration force when the fuel injection pressure “Pinj” is “P1”. As is understood from curve “Pinj=P1”, in the above-mentioned swirl type and multi-nozzle type fuel injection valves, the penetration force sharply increases at an initial stage of the fuel injection and the increasing rate of the force gradually lowers with passage of time. In other words, in such fuel injection valves, a sharp increase of the penetration force is not effected at a middle stage of the fuel injection. Hitherto, it has been thought that the characteristic indicated by curve “Pinj=P1” is generally constant and shows substantially no change even when the fuel injection pressure “Pinj” is varied.
[0016] Due to various experiments carried out by the inventors, it has been revealed that when the fuel injection pressure “Pinj” is increased higher than a critical value “Pcrit”, the penetration force is sharply increased at the middle stage of the fuel injection as is indicated by curve “Pinj=P2”. That is, under such pressure condition, there is produced an atomized fuel of which injection speed is accelerated at the middle stage of the fuel injection. As will be described in detail hereinafter, such unique phenomenon is practically employed in the second fuel injection mode of the fuel injection valve. The inventors have revealed that such speed acceleration of the injected atomized fuel is caused by presence of two phases possessed by the fuel injection, which are a first phase wherein air is given kinetic energy from the fine droplets of the atomized fuel and a second phase wherein the floating fine droplets is drawn by the flow of the atomized fuel with the assistance of the kinetic energy added air. Hitherto, only the first phase has been realized. The inventors consider that when the second phase becomes marked, the second phase overcomes the first phase to induce such a phenomenon that the speed of the atomized fuel from the fuel injection nozzle is sharply increased at the middle stage of the fuel injection.
[0017] Accordingly, when the fuel injection pressure “Pinj” is increased to a level higher than the critical value “Pcrit”, the above-mentioned second fuel injection mode is established. As is seen from the graph of FIG. 1A , when the fuel injection pressure “Pinj” is further increased to values “P2”, “P3” and “P4” (P1<P2<P3<P4), the penetration force of the injected fuel is increased accordingly.
[0018] In the present invention, the above-mentioned unique phenomenon revealed by the inventors is practically used. That is, by controlling the penetration force of the injected fuel in accordance with the operation condition of the engine, the fuel consumption characteristic and exhaust characteristic are improved.
[0019] In the present invention, under a lower engine speed, the fuel injection is carried out with a normal lower injection pressure so that with a lower penetration force, the atomized fuel from the injection nozzle produces a circulation of the atomized fuel in the cavity to produce an appropriate air-fuel mixture. While, under a higher engine speed, the fuel injection is carried out with a higher injection pressure so that with a higher penetration force, the atomized fuel from the injection nozzle produces an air-fuel mixture in a shorter time, the air-fuel mixture being substantially identical to the air-fuel mixture provided by the normal lower injection pressure with respect to the same ignition timing.
[0020] In the invention, under a lower engine load, the fuel injection pressure is reduced to reduce the penetration force thereby to produce an air-fuel mixture in a part of the cavity. While, under a higher engine load, the fuel injection pressure is increased to increase the penetration force thereby to produce a homogeneous air-fuel mixture in the cavity.
[0021] For improving the fuel consumption characteristic, the present invention proposes such a measure that after the fuel injection is carried out to produce an air-fuel mixture that is somewhat leaner than stoichiometric, an additional fuel injection is carried out at a timing just before the ignition by an ignition plug. With this measure, before the ignition, the air-fuel mixture placed around the ignition plug produces a condition that is appropriate for the fuel consumption characteristic.
[0022] It is said that when a fuel injection is carried out under a lower temperature condition of the engine, that is, under a condition wherein the temperature of engine cooling water is relatively low, the amount of unburnt hydrocarbons (HC) in the exhaust gas is increased. However, in the present invention, provision of the above-mentioned second phase suppresses or at least minimizes such undesired phenomenon. That is, under the second phase, the moving speed of air at the leading end of the injected atomized fuel is higher than that of the fine fuel droplets and thus there a partial Weber's value is small thereby inducing a reduction of the fuel droplets collected on the peripheral wall surface of the cavity. Thus, increasing the fuel injection pressure under such lower temperature condition of the engine is an effective way to reduce exhaust emission.
[0023] Although the above description is directed to fuel injection valves of the type-wherein the penetration force of the injected atomized fuel is controlled by the fuel injection pressure “Pinj”, it is also possible to use fuel injection valves of a type that has a plurality of injection nozzles which are controllable in operation. That is, by controlling the number of the injection nozzles that are operative, the characteristic of the penetration force of the injected atomized fuel is varied or controlled. Furthermore, it is possible to use the injection valves of a type wherein the diameter of the fuel injection nozzle is controllable.
[0024] As will be described in detail in the following, in accordance with the present invention, the penetration force of the injected atomized fuel is varied in accordance with the operation condition of the engine. With this measure, a stratified combustion of mixture can be carried out in an expanded operation range of the engine, and deterioration of emission characteristic at a higher engine speed can be suppressed or at least minimized.
[0025] If desired, under the second fuel injection mode, a split fuel injection may be carried out.
[0026] In accordance with a first aspect of the present invention, there is provided a direct fuel injection type internal combustion engine, which comprises a combustion chamber having a piston movably received therein, the piston having a cavity; a fuel injection valve arranged to inject fuel against a wall of the cavity of the piston thereby to produce an air-fuel mixture; an ignition plug arranged to ignite the air-fuel mixture; and a control unit that is configured to carry out controlling the fuel injection valve to have a first fuel injection mode wherein a penetration force of an injected fuel sharply increases at an initial stage of the fuel injection and thereafter an increasing rate of the penetration force gradually lowers with passage of time and a second fuel injection mode wherein the penetration force of the injected fuel sharply increases at a middle stage of the fuel injection; and switching the first and second fuel injection modes in accordance with an operation condition of the engine.
[0027] In accordance with a second aspect of the present invention, there is provided a method for controlling a direct fuel injection type internal combustion engine. The engine comprises a combustion chamber having a piston movably received therein, the piston having a cavity; a fuel injection valve arranged to inject fuel against a wall of the cavity of the piston thereby to produce an air-fuel mixture; and an ignition plug arranged to ignite the air-fuel mixture. The method comprises controlling the fuel injection valve to have a first fuel injection mode wherein a penetration force of the injected fuel sharply increases at an initial stage of the fuel injection and thereafter an increasing rate of the penetration force gradually lowers with passage of time and a second fuel injection mode wherein the penetration force of the injected fuel sharply increases at a middle stage of the fuel injection; and switching the first and second fuel injection modes in accordance with an operation condition of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1A is graph showing a relation between a time elapsed from a fuel injection and a penetration force of the injected fuel, in case wherein the fuel injection pressure is varied;
[0029] FIG. 1B is an illustration showing the shape of an injected atomized fuel from a fuel injection valve;
[0030] FIG. 2 is a sectional view of an essential part of a direct fuel injection type internal combustion engine according to the present invention;
[0031] FIGS. 3A and 3B are drawings showing a process of producing an air-fuel mixture in a combustion chamber under a lower engine speed;
[0032] FIGS. 4A and 4B are drawings showing a process of producing an air-fuel mixture in the combustion chamber under a higher engine speed;
[0033] FIG. 5 is a schematically illustrated sectional view of a swirl type fuel injection valve;
[0034] FIG. 6 is a sectional view taken along the line “A-A” of FIG. 5 ;
[0035] FIG. 7 is a schematically illustrated sectional view of a multi-nozzle type fuel injection valve; and
[0036] FIG. 8 is a view taken from the direction of the arrow “B” of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0037] In the following, the present invention will be described in detail with reference to the accompanying drawings.
[0038] Referring to FIG. 2 , there is shown a direct fuel injection type internal combustion engine of the present invention.
[0039] As shown, the engine generally comprises a cylinder head 1 with intake and exhaust ports 7 and 9 , a cylinder block 2 with cylinders 3 (only one is shown) and pistons 4 (only one is shown). A combustion chamber 5 is defined in each cylinder 3 above the corresponding piston 4 . Combustion chamber 5 is communicated with air intake port 7 through an intake valve 6 , and communicated with exhaust port 9 through an exhaust valve 8 . Intake valve 6 and exhaust valve 8 are driven to open and close by intake and exhaust valve actuating cams 21 and 22 , respectively.
[0040] As shown, at an upper wall surface of combustion chamber 5 , that is, at a portion of cylinder head 1 that defines an upper center part of the combustion chamber 5 , there is arranged a fuel injection valve 11 that has a fuel injection nozzle 11 a from which fuel is injected toward piston 4 . A fuel injection center line (viz., the line along which the fuel is injected from fuel injection nozzle 11 a ) is consistent with a center axis of the cylinder 3 .
[0041] Beside fuel injection valve 11 , there is arranged an ignition plug 12 . As shown, a spark generation head of ignition plug 12 is located in the vicinity of fuel injection nozzle 11 a of fuel injection valve 11 .
[0042] Operation of fuel injection valve 11 and that of ignition plug 12 are controlled by instruction signals issued from an engine control unit 23 . Control unit 23 has a microcomputer that comprises CPU, RAM, ROM and input and output interfaces. That is, in accordance with an operation condition of the engine, fuel injection operation of the valve 11 and ignition operation of the plug 12 are controlled.
[0043] Although not shown in the drawing, before reaching fuel injection valve 11 , fuel is highly compressed by a fuel pump and regulated by a pressure regulator to have a desired high fuel injection pressure. Thus, when the valve 11 opens, the highly compressed fuel is injected into combustion chamber 5 from fuel injection nozzle 11 a . The pressure regulator is controlled by engine control unit 23 so that the fuel injection pressure is controlled in accordance with the operation condition of the engine.
[0044] Furthermore, as is shown in the drawing, piston 4 is formed at a center of the crown part with a generally cylindrical cavity 13 . The cavity 13 is of a reentrant type, so that under a stratified combustion mode of the engine, a stratified air-fuel mixture is produced in or over the cavity 13 .
[0045] When the fuel injection is carried out in the compression stroke, particularly at an end half of the compression stroke, stratified combustion of air-fuel mixture is achieved, which enables operation of the engine at a leaner air-fuel ratio realizing improvement in a fuel consumption.
[0046] In the present invention, the fuel injection pressure is changed between a case wherein the engine speed is relatively low and a case wherein the engine speed is relatively high, so that the injected atomized fuel is able to have a penetration force that is suitable for producing stratified combustion of air-fuel mixture.
[0047] In the following, the detail of the present invention will be described with reference to FIGS. 3A, 3B , 4 A and 4 B.
[0048] FIGS. 3A and 3B show a process of producing an air-fuel mixture in combustion chamber 5 under a lower engine speed, while FIGS. 4A and 4B shows a process for producing the air-fuel mixture in combustion chamber 5 under a higher engine speed.
[0049] When the engine speed is relatively low, the fuel injection is carried out with a normal injection pressure. As is seen from FIG. 3A , in such case, the fuel injection is carried out at an end stage of compression stroke. Upon injection, the injected atomized fuel “F” is forced to produce a circulation of the atomized fuel in the cavity 13 of piston 4 thereby to form a flying up air-fuel mixture. Upon this, ignition is applied to the air-fuel mixture by ignition plug 12 as is seen from FIG. 3B . With these steps, a clear boundary surface is produced between air party and air-fuel mixture party, that is needed for carrying out the stratified combustion of the mixture.
[0050] As is known, when the engine speed increases, the reciprocating speed of piston 4 is increased accordingly. This means that with increase of the engine speed, a real time for work possessed by piston 4 with respect to a unit crank angle becomes shorter. Accordingly, if, under a high speed operation of the engine, the fuel injection is made at the same timing as in the above-mentioned lower speed operation of the engine, the interval from termination of the fuel injection to the ignition fails to have a sufficient time for sufficiently vaporizing the fuel, which tends to cause deterioration of the exhaust characteristic (particularly, soot in the exhaust gas). If, for avoiding such undesirable phenomenon, the fuel injection timing is advanced, the interval from the fuel injection termination to the ignition can have a sufficient time for the fuel vaporization. However, in this case, the fuel injected at an initial stage of the fuel injection is subjected to a diffusion without colliding against the peripheral wall wall of cavity 13 , which seriously affects production of the circulation of the atomized fuel in cavity 13 .
[0051] While, in the present invention, when the engine speed is high, the fuel injection pressure is controlled higher than the critical value “Pcrit” to increase the penetration force of the injected atomized fuel, and at the same time, as is seen from FIG. 4A , the fuel injection is started at a timing that is somewhat advanced as compared with the timing set when the engine speed is low, that is, at a timing that is nearer to BDC (bottom dead center) of intake stroke than that set when the engine speed is low. With this measure, due to the higher penetration force given to the injected atomized fuel “F”, the injected atomized fuel “F” can assuredly reach the cavity 13 of piston 4 and thus appropriate air-fuel mixture is produced in and over the cavity 13 . Furthermore, as shown in FIG. 4B , the interval from the fuel injection termination to the ignition can have a sufficient time for the vaporization of fuel.
[0052] FIGS. 5 and 6 show a swirl type fuel injection valve 11 A that can be used as the fuel injection valve 11 .
[0053] As is seen from FIG. 5 , the swirl type fuel injection valve 11 A comprises a cylindrical housing 31 that has at its leading end a circular fuel injection nozzle 34 . The nozzle 34 is concentric with an axis “O” of housing 31 and tapered at its inside part 34 a , as shown. Within housing 31 , there is axially movably received a needle valve 32 that has a cone-shaped head 32 a that is intimately contactable with the tapered inside part 34 a of nozzle 34 . That is, when cone-shaped head 32 a of needle valve 32 is seated onto tapered inside part 34 a , valve 11 A assumes its close position. An actuator 33 constructed of a piezoelectric element is installed in housing 31 to actuate needle valve 32 . For energizing actuator 33 , electric wires 40 from a power source (not shown) are connected to actuator 33 . A circular partition plate 38 is axially movably received in housing 31 at a position between needle valve 32 and actuator 33 . The needle valve 32 , partition plate 38 and actuator 33 are connected to constitute a single unit. The partition plate 38 has therearound a seal ring 39 for assuring a hermetical sealing between partition plate 38 and housing 31 . A cylindrical projection is formed on housing 31 , that has therein a fuel inlet passage 37 connected to the interior of housing 31 . A highly compressed fuel from a fuel pump (not shown) is led into the interior of housing 31 through fuel inlet passage 37 . When, actuator 33 is energized, the entire length of the same is somewhat reduced due to nature of the piezoelectric element. Upon this, needle valve 32 is lifted up to open nozzle 34 permitting injection of the highly compressed fuel in housing 31 to the outside, that is, toward cavity 13 of the piston 4 .
[0054] Within a lower part of housing 31 , there is arranged an annular swirl chip 36 that surrounds needle valve 32 . As is seen from FIG. 6 , annular swirl chip 36 is formed at its annular lower end and its cylindrical outer surface with equally spaced six fuel guide grooves 41 and equally spaced six fuel flow passages 42 respectively. These fuel guide grooves 41 and fuel flow passages 42 are respectively connected to one another. As shown in the drawing, each fuel guide groove 41 inclines with respect to an imaginary plane that extends along the axis of annular swirl chip 36 , and each fuel flow passage 42 extends axially. More specifically, each fuel guide groove 41 is so oriented as to extend in a tangential direction of cylindrical needle valve 32 . With such inclined arrangement of fuel guide grooves 41 , the compressed fuel directed toward nozzle 34 can be applied with a swirl force.
[0055] Thus, when, due to lifting of needle valve 32 , fuel injection valve 11 A is turned open, the compressed fuel from the six fuel flow passages 42 is forced to run in the six fuel guide grooves 42 toward injection nozzle 34 in the tangential direction of needle valve 32 . Thus, as is mentioned hereinabove, the fuel is applied with a suitable swirl force and thus, the injected atomized fuel can take a hollow cone shape in combustion chamber 5 .
[0056] FIGS. 7 and 8 show a multi-nozzle type fuel injection valve 11 B that can be used also as the fuel injection valve 11 .
[0057] Since the basic construction of this valve 11 B is substantially the same as that of the above-mentioned swirl type valve 11 A, only portions or parts that are different from those of the swirl type valve 11 A will be described in detail in the following. The same parts are denoted by the same numerals as in the swirl type.
[0058] In this multi-nozzle type fuel injection valve 11 B, the housing 31 has at its leading end eight equally spaced fine fuel injection nozzles 51 that are arranged circumferentially around the axis “O” of housing 31 . As shown in FIG. 7 , the leading end of housing 31 is formed at its inside surface with a cone-shaped recess 34 b to which the eight injection nozzles 51 are exposed. The cone-shaped head 32 a of needle valve 32 is intimately contactable with the cone-shaped recess 34 b . That is, when cone-shaped head 32 a is seated onto the cone-shaped recess 34 b , the valve 11 B assumes its close position. The fuel injection nozzles 51 are inclined relative to the axis “O” of housing 31 . More specifically, each fuel injection nozzle 51 is so inclined that a distance between nozzle 51 and the axis “O” increases with increase of the distance from cone-shaped recess 34 b . An annular chip 52 is arranged to surround needle valve 32 . The annular chip 52 is formed at its annular lower end and its cylindrical outer surface with equally spaced fuel guide grooves 41 A and equally spaced fuel flow passages 42 respectively, like in case of the above-mentioned swirl type valve 11 A. However, in the valve of the multi-nozzle type 11 B, fuel guide grooves 41 A of the annular chip 52 are arranged to extend radially outward from the axis “O” of housing 31 .
[0059] When, due to lifting of needle valve 32 , fuel injection valve 11 B is turned open, the compressed fuel in fuel flow passages 42 of annular chip 52 is forced to run in the fuel guide grooves 41 A toward the eight fine nozzles 51 , so that the injected atomized fuel from the nozzles 51 can take a hollow cone shape in combustion chamber 5 .
[0060] The entire contents of Japanese Patent Application 2003-288318 filed Aug. 7, 2003 are incorporated herein by reference.
[0061] Although the invention has been described above with reference to the embodiments of the invention, the invention is not limited to such embodiments as described above. Various modifications and variations of such embodiments may be carried out by those skilled in the art, in light of the above description.
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A control unit is used for controlling a direct fuel injection type internal combustion engine. The control unit controls a fuel injection valve to have a first fuel injection mode wherein a penetration force of an injected fuel sharply increases at an initial stage of a fuel injection and thereafter an increasing rate of the penetration force gradually lowers with passage of time and a second fuel injection mode wherein the penetration force of the injected fuel sharply increases at a middle stage of the fuel injection. The control unit further controls the fuel injection valve in a manner to switch the first and second fuel injection modes in accordance with an operation condition of the engine.
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RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 733,744, filed Oct. 19, 1976 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Diver heating and work energy apparatus.
2. Description of the Prior Art
Presently a common method of heating a diver while submerged and ambulatory involves the heating of water at a diver-remote site and the pumping of such hot water to the diver for circulation through conduits in his diving suit, as in U.S. Pat. No. 3,519,021 to Wiswell, Jr. This usually is in addition to transmitting power to him for operating work tools when required. Transmission of such hot water to the diver occurs by way of a flexible hose that is subjected at its exterior to the low temperature ambient water which tends to provoke considerable thermal loss. The use of thermal insulation around the hot water hose tends to render the hose bulky and difficult to manipulate.
Preliminary novelty search in the U.S. Pat. and Trademark Office has uncovered several patents that disclose the power-generation use of seawater to a limited extent and for a short duration on an emergency basis by flow from the exterior to an interior chamber in a submerged vessel: U.S. Pat. Nos. 3,504,648 Kriedt; 3,418,818 Vincent el al; 3,163,985 Bouyoucos; and 3,003,448 Gay Jr. One, 3,103,195 to Cousteau et al, discloses use of bottled-gas-driven seawater pumps for vessel propulsion, and another, 1,466,315 to Thorsen, operates an hydraulically driven hull scrubber device that uses the deck water conduit on the ship being scrubbed.
A number of patents disclose apparatus for generation of heat from flow hydraulic fluid in a closed loop through a friction means; U.S. Pat. Nos. 3,813,036 to Lutz for a residential heating system; 3,333,771 to Graham for a belt joint vulcanizer; 2,764,147 to Brunner for an aircraft hydraulic system heater; and 2,107,933 to Crockett et al for a system for heating buildings, vehicles, compartments, etc.
One patent, U.S. Pat. No. 3,815,573 to Marcus, discloses a compressed-gas-operated vortex-tube type heat generator for heating a diver's suit by circulation of hot liquid through a gas-to-liquid heat exchanger. The gas used is the bottled breathing gas carried by the diver, or furnished as breathing air via line from the surface.
SUMMARY OF THE INVENTION
The present invention, in transmitting relatively low temperature pressurized seawater to the diver for conversion into heat, rather than high temperature hot water, greatly reduces the potential thermal loss via the heat supply hose and obviates need for cumbersome thermal insulation of the hose. The use of seawater, or other ambient water, as the case may be, for transmission to the diver is expedient, inasmuch as it is readily available and locally exhaustible without polluting.
The use of seawater for tramsmission to the diver also is relatively practical, as compared to the use of compressed gas for such transmission. The column of seawater in the downwardly extending supply hose develops the same hydrostatic elevation pressure as that of the surrounding sea, so that the liquid pumping means at the surface need deliver only that work required to overcome friction in the supply hose, plus any pressure head needed for the intended work function at the diver site. Pumping pressurized gas, on the other hand, requires compression of the gas just to enable it to overcome the hydrostatic head of the water column tending to be forced into the lower end of the hose. At diver depths of many hundreds of feet, such energy-demanding hydrostatic-head-overcoming gas compression can be considerable. At the same time, expansion of compressed gas for creation of heat or performing work results in cooling of such gas to a relatively low temperature at its exhaust. This, coupled with a low ambient water temperature can lead to complication of the equipment in behalf of avoiding freeze-up.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view, partly in outline and partly in section, of an illustrative embodiment of the present invention as affiliated with several divers at two different submerged sites as availed with seawater under pressure from a support vessel at the surface;
FIGS. 2a to 2d are schematic showings of different hydraulic circuit arrangements which may be embodied in the apparatus of the present invention to produce heat at the diver site by flow of seawater under pressure to such site from a surface site;
FIG. 3 is a schematic showing of a reciprocating-piston motor and pump arrangement suitable for embodiment in such as the exemplified hydraulic circuits of FIGS. 2a to 2d; and
FIG. 4 is a longitudinal cross section view of a rotary hydraulic motor and pump construction suitable for use in the present invention as an alternative to the reciprocating-piston motor-pump used in the FIG. 3 arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 the diver support apparatus of the present invention is shown affiliated with a support vessel 1 floating on a sea surface 2 above submerged divers 3 and 4 at two different underwater sites; one being located within a submerged breathing chamber 5 and the other being outside such chamber and furnished with breathing gas from the chamber by way of push-pull breathing gas lines 6 and 7, respectively.
According to the present invention, water from the body of ambient water 8 in which the chamber 5 and divers 3 and 4 are submerged is drawn into a precharge pump 9 via a filter-inlet 10, thence to a supply pump 11 via a filter 12 for pressurizing and delivery to breathing gas chamber 5 and to diver 4 via a pump outlet 13 and a flexible pressurized water supply line 14 and branches thereof.
At the breathing chamber 5, the pressurized seawater arriving via supply line 14 will flow through such as a seawater-operated turbine 15, or other suitable hydraulic motor, to operate such as an electric generator 16 to energize lighting means 17', for example; a gas compressor 17 for operating pneumatic equipment, for example; a hydraulic pump 18 for operating hydraulic equipment, for example; a gas circulation blower 19 for circulating breathing gas within the chamber; and a heat-producing conversion means including a pump 20 for closed-loop circulation of liquid sequentially through a flow restricting means 21 to create hydraulic friction heat within such liquid and then through a heat exchanger 22 to transfer such heat to the interior of such chamber, in accord with the present invention. A hot liquid return chamber 23 completes the heating liquid loop through the pump 20.
The interior of the chamber 5 can be availed with breathing gas, such as a mixture of helium and oxygen, from storage tanks 25 mounted outside the chamber and regulated automatically to maintain a desired oxygen level by gas control means 26 that includes a scrubber means for removal of carbon dioxide from the chamber gas. A diver, such as the diver 3, disposed within the chamber 5 site, is free to remove his helmet, mask, or headgear and breathe the gas within the chamber, as is well known in the art and, in accord with the present invention, to be availed of heat, or/and lighting, pneumatic power, hydraulic power, etc., produced by the flow of low temperature seawater under pressure from the surface site at vessel 1 to the turbine 15. Discharge of seawater from the turbine 15 is free to occur into the sea 8 via an exhaust line 27.
At another site the diver 4 is availed of breathing gas from the interior of the chamber 5 such as by way of the supply and return lines 6 and 7, his diving helmet 30 and suitable valve means (not shown). In accord with adjunctive features of the present invention, supply and return pumps 31 and 32 for the breathing gas lines 6 and 7, respectively, can be driven by a hydraulic motor 33 operated by the low temperature seawater under pressure from a branch of the supply line 14. At the same time, another branch of such pressurized seawater supply line 14 extends to the diver 4 at a site outside the chamber 5 to a hydraulically operated heat-producing conversion device 35. Device 35 is designed to be compact, lightweight, and efficient, for disposition on the diver, such as at his waist, as shown, or at any other suitable location at the diver. Device 35 contains a means for converting flow of the low temperature pressurized seawater from the line 14 into heat, and for passing a liquid medium containing such heat through passage 36 in the diver's suit 37 to maintain comfort and warmth of the diver. The heated liquid medium supplied to the heating passages 36 in the diver's suit 37 may be the seawater or it may be a secondary liquid. Different hydraulic heat-producing-conversion-means circuits suitable for use in the apparatus of the present invention are shown in FIGS. 2, 3, and 4. Some may be more suitable for use at the diver site within the breathing chamber 5, while others may be more suitable for use at the external diver site mounted on the diver.
For example, referring to FIG. 2a, the circuit disclosed therein includes a hydraulic motor 40 operated by low-temperature pressurized seawater from line 14 to drive a pump 41 that forces seawater also from the line 14 through a hydraulic-friction-heat-producing flow restriction means 42 and a heat exchanger 43. Exhaust from the motor 40 and from the heat exchanger may simply bleed into the sea 8.
Referring to FIG. 2b, a hydraulic motor 40 driven by low-temperature pressurized seawater from line 14 and exhausting into the ambient water 8 drives a pump 41 that circulates a liquid medium through a closed loop that includes a hydraulic-friction-heat-producing flow restricting means 42 and a heat exchanger means 43.
FIG. 2c shows an arrangement where part of the discharge from the hydraulic motor 40 serves as input to the pump 41 which forces the seawater through the heat-producing flow restriction means 42 and heat exchanger means 43. Some discharge from the restriction means 42 is allowed to recirculate through the pump 41, however, via a by-pass line 44.
FIG. 2d is similar to the circuit of FIG. 2c, but includes an additional recirculation loop line 45 around the heat exchanger 43.
It will be apparent that other hydraulic circuit variations may be employed to advantage to suit particular component characteristics or preferred operating parameters, such as flow-adjusting restrictors, use of recovery heat exchangers, all within the spirit and scope of the present invention.
Several different types of motor-pump combinations may be employed in the foregoing hydraulic circuits. FIG. 3 depicts a reciprocating type in which a motor piston 47 is reciprocably driven by periodic supply of low-temperature seawater under pressure from supply line 14 alternately to its opposite faces under control of a four-way valve means 48, and a pump piston 50 driven by motor piston 47. Pump piston 50 discharges alternately from its opposite faces to force the flow of liquid medium through the hydraulic-friction-heat-creating flow restriction means 42 and heat exchanger means 43 via a system of check valves 52 arranged like a full-wave bridge rectifier in simple AC-to-DC electrical conversion circuitry. By compounding the number of motor and pump pistons, a triplex or quadraplex arrangement can be obtained for smoother discharge flow. The several pump pistons can be made to operate in an out-of-phase relationship to obtain the desired pulsation-reducing effect.
A motor-pump assemblage that appears to be particularly suited for use as the heat-producing conversion device 35 at the diver 4 or the turbine-pump 15--20 combination is shown in FIG. 4. Here the assemblage employs hydraulic motor and pump of the rotary type. A water turbine rotor 52 rotatable about axis 52a is driven by pressurized seawater flow from the line 14 to turn a pump rotor 53 that can be, as depicted in FIG. 4, of an inefficient design from a pumping performance point of view, lossy or of high-loss, with such an amount of clearance between the rotor's blades 53a and the wall of the chamber 53b in which such blades are being turned about axis 52a that considerable churning, swirling, or turbulence as indicated by the arrows 53c, takes place while such blade rotation induces ingress of liquid medium via a coaxial inlet port 54 and discharge of such medium via a radial outlet 55 after such medium has experienced a heating effect from the hydraulic friction created by the inefficiently operating blades 53a. Such heated liquid medium, via inlet 54 and outlet 55, becomes circulated by such operation of the lossy rotor 53 through a heat exchange circuit, such as depicted in FIGS. 2a to 2d, where device 35 is represented schematically by the hydraulic motor 40-and-pump 41 combination, and heat passages 36 in the diver's suit 37 are represented by the heat exchanger 43. Non-recirculated, single-pass operation of the pump 41 tends to be inefficient from a heating point of view, excess pressurization and flow of low-temperature pressurized ambient liquid through the hydraulic motor operating the pump.
In lieu of generating the hydraulic friction heat substantially by rotation of the "lossy" rotor 43 depicted in FIG. 4, a close-clearance-bladed rotor of high pumping efficiency may be employed and such heat created substantially entirely by flow through the restricting means 42 in the heating liquid medium circuit.
With adequate flow (2 gpm, for example) and pressure (2000 psi, for example) a device 35 of less than three inches in diameter and less than four inches long can generate heat energy equivalent to several kilowatts, about one hundred btu/minute.
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Apparatus for supporting the life, safety, comfort, and usefulness of an underwater diver by pumping seawater, or other ambient water in which the diver may be located, under pressure from a surface site to the submerged diver site, and locally converting by hydraulic friction at the diver site the hydraulic energy of such pressurized pumped seawater into diver-warming heat or/and mechanical energy for operating tools, pumps, etc.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 12/171,734, filed Jul. 11, 2008, currently pending, entitled “A Technique for Forming the Deep Doped Columns in Superjunction,” which is a divisional application of U.S. patent application Ser. No. 11/343,329, filed Jan. 31, 2006, now U.S. Pat. No. 7,504,305, entitled “A Technique for Forming the Deep Doped Columns in Superjunction,” which is a continuation of U.S. patent application Ser. No. 10/857,323, filed May 28, 2004, now U.S. Pat. No. 7,015,104, entitled “A Technique for Forming the Deep Doped Columns in Superjunction,” which claims the benefit of U.S. Provisional Patent Application No. 60/474,127, filed on May 29, 2003, entitled “A Technique for Forming the Deep Doped Columns in Superjunction.”
BACKGROUND OF THE INVENTION
The present invention relates generally to semiconductor devices, and more, particularly, to power MOSFET devices.
Power MOSFET devices are employed in applications such as automobile electrical systems, power supplies, and power management applications. Such devices should sustain high voltage in the off-state while having a low voltage drop and high current flow in the on-state.
FIG. 1 illustrates a typical structure for an N-channel power MOSFET. An N-epitaxial silicon layer 1 formed over an N + silicon substrate 2 contains P-body regions 5 a and 6 a , and N + source regions 7 and 8 for two MOSFET cells in the device. P-body regions 5 and 6 may also include deep P-body regions 5 b and 6 b . A source-body electrode 12 extends across certain surface portions of epitaxial layer 1 to contact the source and body regions. The N-type drain for both cells is formed by the portion of N-epitaxial layer 1 extending to the upper semiconductor surface in FIG. 1 . A drain electrode is provided at the bottom of N + substrate 2 . An insulated gate electrode 18 typically of polysilicon lies primarily over the body and portions of the drain of the device, separated from the body and drain by a thin layer of dielectric, often silicon dioxide. A channel is formed between the source and drain at the surface of the body region when the appropriate positive voltage is applied to the gate with respect to the source and body electrode.
The on-resistance of the conventional MOSFET shown in FIG. 1 is determined largely by the drift zone resistance in epitaxial layer 1 . The drift zone resistance is in turn determined by the doping and the layer thickness of epitaxial layer 1 . However, to increase the breakdown voltage of the device, the doping concentration of epitaxial layer 1 must be reduced while the layer thickness is increased. Curve 20 in FIG. 2 shows the on-resistance multiplied by unit area as a function of the breakdown voltage for a conventional MOSFET. Unfortunately, as curve 20 shows, the on-resistance times area of the device increases rapidly as its breakdown voltage increases. This rapid increase in on-resistance times area presents a problem when the MOSFET is to be operated at higher voltages, particularly at voltages greater than a few hundred volts.
FIG. 3 shows a MOSFET that is designed to operate at higher voltages with a reduced on-resistance. This MOSFET is disclosed in paper No. 26.2 in the Proceedings of the IEDM, 1998, p. 683. This MOSFET is similar to the conventional MOSFET shown in FIG. 2 except that it includes P-type doped regions 40 and 42 which extend from beneath the body regions 5 and 6 into the drift region of the device. The P-type doped regions 40 and 42 define columns in the drift region that are separated by N-type doped columns, which are defined by the portions of the epitaxial layer 1 adjacent the P-doped regions 40 and 42 . The alternating columns of opposite doping type cause the reverse voltage to be built up not only in the vertical direction, as in a conventional MOSFET, but in the horizontal direction as well. As a result, this device can achieve the same reverse voltage as in the conventional device with a reduced layer thickness of epitaxial layer 1 and with increased doping concentration in the drift zone. Curve 25 in FIG. 2 shows the on-resistance times area as a function of the breakdown voltage of the MOSFET shown in FIG. 3 . Clearly, at higher operating voltages, the on-resistance times area of this device is substantially reduced relative to the device shown in FIG. 1 , essentially increasing linearly with the breakdown voltage.
The improved operating characteristics of the device shown in FIG. 3 are based on charge compensation in the drift region of the transistor. That is, the doping in the drift region is substantially increased, e.g., by an order of magnitude or more, and the additional charge is counterbalanced by the addition of columns of opposite doping type. The blocking voltage of the transistor thus remains unaltered. The charge compensating columns do not contribute to the current conduction when the device is in its on-state. These desirable properties of the transistor depend critically on the degree of charge compensation that is achieved between adjacent columns of opposite doping type. Unfortunately, non-uniformities in the dopant gradient of the columns can be difficult to avoid as a result of limitations in the control of process parameters during their fabrication. For example, diffusion across the interface between the columns and the substrate and the interface between the columns and the P-body region will give rise to changes in the dopant concentration of the portions of the columns near those interfaces.
The structure shown in FIG. 3 can be fabricated with a process sequence that includes multiple epitaxial deposition steps, each followed by the introduction of the appropriate dopant. Unfortunately, epitaxial deposition steps are expensive to perform and thus this structure is expensive to manufacture. Another technique for fabricating these devices is shown in co-pending U.S. application Ser. No. 09/970,972, in which a trench is successively etched to different depths. A dopant material is implanted and diffused through the bottom of the trench after each etching step to form a series of doped regions (so-called “floating islands”) that collectively function like the P-type doped regions 40 and 42 seen in FIG. 3 . However, the on-resistance of a device that uses the floating island technique is not as low as an identical device that uses continuous columns.
Accordingly, it would be desirable to provide a method of fabricating the MOSFET structure shown in FIG. 3 that requires a minimum number of deposition steps so that it can be produced less expensively while also allowing sufficient control of process parameters so that lightly doped columns that extend almost through a layer of deposited can be formed.
SUMMARY OF THE INVENTION
A method of manufacturing a semiconductor device is disclosed and starts with a semiconductor substrate having a heavily doped N region at the bottom main surface and a lightly doped N region at the top main surface. There are a plurality of trenches in the substrate, with each trench having a first extending portion extending from the top main surface towards the heavily doped region. Each trench has two sidewall surfaces in parallel alignment with each other. A blocking layer is formed on the sidewalls and the bottom of each trench. Then a P type dopant is obliquely implanted into the sidewall surfaces to form P type doped regions. The blocking layer is then removed. The bottom of the trenches is then etched to remove any implanted P type dopants. The implants are diffused and the trenches are filled.
The body and the source regions are then formed after the gate dielectric and the gate conductor are formed. The body region consists of an implanted P body region on top of each of the diffused P type doped regions to form the body regions and implanted N + regions within the body regions to form source regions. Above the gate dielectric region is a gate conductor that extends over the P-type body and the N + source regions of two adjoining trenches. A source conductor is connected to the P-type body and the N + source region.
The un-doped sidewalls will typically be doped with N type dopant. The trenches may have the shape of a dog bone, a rectangle, a rectangle with rounded ends or a cross with the P type dopant being implanted into the ends of the dog bone, a rectangle, or a rectangle with rounded ends, and in opposite sides of the cross.
Rectangular-shaped trenches may be arranged in an array of rows and columns with the ends of the trenches in the column being implanted with P type dopants and the ends of the trenches in the rows being implanted with N type dopants. Cross-shaped trenches may be implanted with P-type dopant along one set of axes, and with N-type dopant along a second set of axes at 90° to the first set.
The angle of the implant can be selected so that the bottoms of the trenches are not implanted.
The technique may be used to manufacture the termination regions by varying the shape, the depth and width of the trenches, in conjunction with the implant angle.
The identification of the type of doping use herein only refers to that shown in the particular embodiment. Those skilled in the art know that similar results may be achieved by using P type dopant instead of N type and visa versa. The use of the particular type of dopant in the description of the embodiments should in no way limit the scope of the claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a sectional view of a prior art conventional MOSFET;
FIG. 2 is a chart showing breakdown voltage, the on-resistances and current;
FIG. 3 is a sectional view of a prior art superjunction transistor;
FIGS. 4-14 illustrate the process steps used to manufacture the disclosed semiconductor device;
FIGS. 15A , 15 B, 15 C, 23 , 24 and 25 illustrate the different shapes that can be used to manufacture the disclosed semiconductor device;
FIGS. 16 , 18 , and 19 illustrate the different arrangements of the trenches to achieve the disclosed device;
FIG. 17 is a sectional view of the disclosed device illustrating the source region;
FIGS. 20 , 26 and 27 illustrate possible termination arrangements of the semiconductor device;
FIG. 21 shows a top view of the termination region; and
FIG. 22 is a sectional view of FIG. 21 .
DETAILED DESCRIPTION OF THE INVENTION
A technique for forming lightly doped columns that extend almost through a layer of deposited epitaxial semiconductor material is best understood by referring to FIGS. 4-18 while reading the description below. This technique uses trenches etched into the silicon to form lightly doped columns. One type of trenches has a dimension in a first direction that is greater than the dimension in a second direction that is perpendicular to the first direction and is generally rectangular shaped, while a second type is cross-shaped. FIG. 16 shows the top view of a series of generally rectangular shaped trenches 35 following two separate implantation steps that have doped the two narrow walls 31 and 33 of the trenches 35 . FIGS. 9 and 10 show the technique that is used to perform the two implantation steps. The two separate implantation steps are performed at an angle with respect to the surface of the substrate that allows the dopant to be implanted into just the two narrow “end” sidewalls 31 and 33 . The presence of a layer of material such as silicon dioxide or silicon nitride (or a sandwich of such materials) prevents the ions that are being implanted from reaching the semiconductor sidewalls 37 that are along the long axis of each trench. Following the implantation step, any dopant that has been implanted in the bottom of the trench may be removed by etching the trench deeper, and then the dopant may be diffused until the desired dopant distribution is obtained. The trench is then filled using an oxidation or deposition step.
The shape of the trench is not limited to just being rectangular. Many other possible trench shapes such as dog-bones 235 ( FIG. 15C ), or rectangles with rounded ends 135 ( FIG. 15B ), or crosses are also possible. The profile of the implanted dopant is slightly different, allowing the optimization of the shape of the implanted region. Both of the trench geometries avoid placing dopant atoms near a corner, which might result in better control of the resulting dopant profile.
The pattern of trenches across the surface of the device may also be varied to obtain the best performance. Examples of trench placement are shown in FIG. 16 which shows a square array 104 , FIG. 18 which shows a staggered array 110 and FIG. 19 which illustrates an array 133 of rows and columns. The number and locations of the trenches is important because it affects overall device efficiency.
One fabrication sequence for the doped columns will now be discussed.
Referring to FIG. 4 a lightly doped epitaxial layer 1 is deposited on a heavily doped substrate 2 . Then as shown in FIG. 5 a blocking layer 41 of silicon dioxide is either grown or deposited on the top surface of the epitaxial. The blocking layer has a desired thickness of between 400 and 2,000 A°. In FIG. 6 the blocking layer 41 is masked by a mask 43 to facilitate its etching. Following the etching of the blocking layer 41 , trenches 45 are etched into the epitaxial layer 1 as illustrated in FIG. 7 . A blocking layer 47 is grown or deposited on all of the sidewalls and bottoms of each trench 45 as is shown in FIG. 8 . The thickness of blocking layer 47 is between 200 and 2000 A°.
Referring to FIG. 9 , a first implant of boron ions is performed in the narrow end 33 at an angle alpha that in conjunction with the thickness of the blocking layer 47 will limit the penetration of the dopant into the epitaxial 1 . The thickness of the blocking layer 47 is sufficient enough to prevent the penetration of the dopant into the tops of the columns 21 . The result is implanted ions 51 in the column 21 at the small side 33 . Generally to prevent the penetrations of the ions in the bottom of the trench alpha should be equal to the tangent G, the depth of the trench, and the width F of the trench.
In FIG. 10 a second implant using the same dopant species is performed at the other small side 31 of the trenches 45 at an angle beta that is traditional equal to 90 degrees minus alpha degrees from the horizontal, leaving implanted ions 52 in the small side 31 as is shown in FIGS. 10 and 11 .
The implants are performed parallel to the long axis, the F side, of the geometry that is used, so no dopant penetrates through the oxide on these sidewalls because of the large angle away from being perpendicular.
In FIG. 12 the trench is etched to remove the blocking layer 47 and any implanted ions at the bottom of the trenches to a depth H shown generally at 53 .
In FIG. 13 a diffusion step is performed to create P-type doped regions 36 and 38 . The trenches 45 are filled with an insulator such as silicon dioxide in FIG. 14 . The trenches can have many different shapes such as the square shape 100 of FIG. 15A , the elongated shape 101 of FIG. 15B , or the dog bone shape 103 of FIG. 15C . No dopant is introduced on the walls at the long sides of the structure for any of the geometries.
The FIGS. 15A , 15 B and 15 C show the location of the implanted dopant 36 and 38 following the first and second implants as shown in FIGS. 9 and 10 .
After dopant implantation and diffusion to form the doped columns, the trenches are filled. Typically a dielectric will be used, though it is possible to fill it with polysilicon and re-crystallize the polysilicon, or to fill the trench with single crystal silicon using epitaxial deposition. Once the surface is planarized, the active region that includes the body, gate dielectric and conductor, and the source regions should be placed anywhere there is no trench present to provide channel regions for carrier flow. For the array 104 of FIG. 16 , active regions can be anywhere in the rows and columns between the trenches. Depending on the dimensions of the trench, polygonal, cellular or stripe geometries are all feasible. A striped geometry might run parallel to the long axis of the trenches (top row of FIG. 16 ). A cellular geometry might enclose each trench as shown on the bottom row of FIG. 16 . If a cell is formed at each end of the trench (middle row of FIG. 16 ), the source injects carriers around 3 sides, but not at the fourth side. The cross section for either cellular version is the same through the doped column and is shown in FIG. 17 .
The Use of Trenches Having Different Orientations in Combination with Implants with Dopants Having Different Conductivity Types is illustrated in FIG. 19 .
The creation of the active region includes the steps of implanting the P type source body region 5 on top of the P columns 36 and 38 . A source 7 of N type dopant is then implanted on top of the source body regions 5 . A gate oxide 6 is deposited and the gate electrode 18 is formed in the gate oxide between the rows 108 and 148 over the sources 7 . Finally, the source electrode is connected to the source and source body region of each device.
A variation of the technique that was previously discussed uses the implantation of dopants of both conductivity types in the active region of the device. In this variation, the second dopant type is implanted at an angle of 90° and 270° to the first dopant implant, as shown in FIG. 19 . It provides the needed amount of dopant compensation and/or charge balance to obtain a high breakdown voltage. Where the structures 11 have N-type dopants implanted at regions 136 and 138 and P-type dopants implanted at regions 36 and 38 . A second set of rectangular trenches 35 that are perpendicular to the first set of trenches 35 provide this capability are shown in FIG. 19 . While geometries that allow the doping of the walls of a single trench with dopants of both conductivity types is shown in FIG. 23 . Unwanted doping of the top region of any sidewall which could occur when two dopants are implanted at 90° to each other can be prevented by using a blocking layer having a greater thickness along the top part of the sidewall than previously shown.
A Compatible Termination Structure
A formation of a termination at the device perimeter that is compatible with the sequence used in the fabrication of the super-junction structure at the center of the device is often a challenge.
In the present embodiment, however, it is possible to form a compatible termination structure by either using the same process sequence, or by adding one more implants to the existing process sequence. These two possibilities are discussed in greater detail below.
A Compatible Termination Structure that Requires No Additional Process Steps
This termination structure is best understood by referring to FIGS. 20-22 . FIG. 20 shows a top view and FIGS. 21 and 22 show a side view of trenches 35 , 121 and 122 at the termination having different lengths, device 207 , dotted line trenched 201 and device 209 and/or having both different lengths and widths trenches 207 , 211 and 200 —and different width trenches 207 , 201 and 205 . The trench length directly determines the depth along the sidewall that is implanted on the two walls at the ends of each trench while the trench width directly affects the total charge introduced in these two sidewalls. By varying the trench length and width, both the depth of the junctions formed by the introduced dopant and the total dopant amount that is introduced can be optimized. By also controlling the number and the locations of the trenches that are etched in the termination region, as shown in FIG. 20 , the positions as well as the depths of the diffused P-type junctions in the termination region can be optimized to produce the highest breakdown voltage.
It is also possible to etch trenches that are not generally rectangular in shape (such as crosses 214 , squares 215 or circles 216 of FIGS. 23-25 ) that may also have different dimensions to etch trenches that are generally rectangular in shape, but with their axes along a line that is different from that of the trenches etched in the active region of the device. Examples of these trenches are shown in FIG. 26 .
A Compatible Termination Structure that Requires an Additional Implant Step
The termination structure uses a second implant step with a dopant having the same conductivity type as that of the region containing the trenches. This additional implant provides dopant that can either partially compensate the dopant from the first implant, or provide charge to balance the dopant introduced by the first implant. By etching a second set of trenches 123 that are generally rectangular shaped, and that have their major axis at an angle offset to the axis of the first set of trenches and by varying the dimensions of the trenches as discussed above, it is possible to control both the location and the amount of dopant introduced. Examples of possible termination trenches of this type are shown in FIG. 26 . It is also possible to etch trenches that are not generally rectangular in shape (such as squares or trenches) that may also have different dimensions or to etch trenches that are generally rectangular in shape with their axes along a line that is different from that of the trenches etched in the active region of the device as is shown in FIGS. 19 and 27 . Implanting the first dopant type along one set of axes and the second dopant type along another set of axes that is 90° to the first set of axes provides the needed amount of dopant compensation and/or charge balance to obtain a high breakdown voltage.
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A method of manufacturing a semiconductor device is disclosed and starts with a semiconductor substrate having a heavily doped N region at the bottom main surface and having a lightly doped N region at the top main surface. There are a plurality of trenches in the substrate, with each trench having a first extending portion extending from the top main surface towards the heavily doped region. Each trench has two sidewall surfaces in parallel alignment with each other. A blocking layer is formed on the sidewalls and the bottom of each trench. Then a P type dopant is obliquely implanted into the sidewall surfaces to form P type doped regions. The blocking layer is then removed. The bottom of the trenches is then etched to remove any implanted P type dopants. The implants are diffused and the trenches are filled.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus and a method for character input.
[0003] 2. Description of Related Art
[0004] Hand-held devices with text input capabilities have become more and more popular. These devices, for example, mobile phones and personal digit assistants, usually adopt a keypad for character input function. The keypad typically has fewer keys than a QWERTY keyboard. Several characters are arranged on a single key of the keypad. For example, a single key represents a number and two or three characters at the same time. Inputting characters on the keypad is time consuming. A user usually needs to operate keys a plurality of times to input one character.
[0005] Therefore, what is needed is an apparatus for rapid character input using a new kind of keypad.
SUMMARY OF THE INVENTION
[0006] An apparatus for character input is disclosed. The apparatus includes a keypad and a processing unit. The keypad comprises a plurality of combo keys. Each combo key includes a main contact and at least one sub-contact adjacent to the main contact. The main contact and the sub-contact respectively have at least one icon representing a character. The processing unit receives a press operation on the keypad and inputting a corresponding character.
[0007] A method for character input which is used in an electronic device is disclosed. The method comprising the steps of: a) Providing a key board. The keypad includes a plurality of combo keys. Each combo key includes a main contact and at least one sub-contact adjacent to the main contact. The main contact and the sub-contact respectively have at least one icon representing a character. b) Depressing a combo key. c) Inputting a corresponding character.
[0008] Further features and advantages will be provided or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic, front view of an electronic device with a keypad according to a first preferred embodiment of the present invention;
[0010] FIG. 2 is a schematic diagram of a hardware infrastructure of the electronic device of FIG. 1 ;
[0011] FIG. 3 is a schematic, front view of the keypad of FIG. 1 ;
[0012] FIG. 4 is a schematic, isometric view of a combo key of FIG. 3 ;
[0013] FIG. 5 is a cross section view of FIG. 4 ;
[0014] FIG. 6 is a flowchart of a preferred method of character input used in the electronic device of FIG. 1 ; and
[0015] FIG. 7 is a schematic, front view of a keypad according to a second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIGS. 1 and 2 , an electronic device 30 with a keypad 10 according to a first preferred embodiment of the present invention is disclosed. The electronic device 30 includes the keypad 10 , a display 31 , a processing unit 32 , and a power supply 33 . The keypad 10 is for inputting characters. The processing unit 32 receives an input from the keypad 10 and displays a corresponding character on the display 31 .
[0017] Referring to FIGS. 3, 4 , and 5 , the keypad 10 and combo keys 15 thereof are disclosed. The keypad 10 includes four key rows 11 , 12 , 13 , 14 . Each key row includes three combo keys 15 . Each combo key 15 includes a main contact 110 , and two sub-contacts 111 , 112 . The two sub-contacts 111 , 112 are on opposite sides of the main contact 110 .
[0018] Each main contact 110 of the key rows 11 , 12 , 13 , 14 has a relatively large primary icon indicating a unique member of a first subset of a character set. The character set is the set of characters found on a typical keyboard. In the first preferred embodiment the first subset of a character set includes the number set, a predetermined symbol, and the space symbol, such as that shown in FIG. 2 . Each main contact 110 of the key rows 11 , 12 , 13 and each sub-contact 111 or 112 of the key rows 11 , 12 , 13 , 14 also has a secondary icon indicating a unique member of a second subset of the character set. In the first preferred embodiment, the second subset includes the English alphabet and punctuation symbol, such as that shown in FIG. 2 .
[0019] A main contact 16 and a sub-contact 17 of key row 14 are respectively designated as a function key for switching between a first input mode and a second input mode. In this embodiment, the first input mode is the number input mode, and the second input mode is the letter input mode. In the number input mode, the main contact 110 of the key rows 11 , 12 , 13 , 14 are employed to input the primary icon (i.e., the number) indicated. In the second input mode, the main contact 110 of the key rows 11 , 12 , 13 are employed to input the secondary icon indicated.
[0020] Each combo key 15 of the keypad is further connected to a rubber pin 113 . The rubber pin 113 includes touch points 130 , 131 , 132 , corresponding to the main contact 110 , the sub-contact 111 , and the sub-contact 112 respectively. A depression of the main contact 110 , the sub-contact 111 , or the sub-contact 112 triggers the touch point 130 , 131 , 132 to electrically connect with an inner circuit (not shown) of the electronic device 30 correspondingly.
[0021] The main contact 110 and the sub-contacts 111 , 112 can be depressed together or independently. When the main contact 110 is depressed, the processing unit 32 is programmed to accept the input from the main contact 110 , and displays the character on the display 31 as depicted by the symbol on the main contact 110 . When sub-contact 111 or when a combination of sub-contact 111 and the main contact 110 is/are depressed, the processing unit 32 is programmed to accept the input from the sub-contact 111 and displays the character on the display 31 as depicted by the symbol on the sub-contact 111 . Similarly, when sub-contact 112 or when a combination of sub-contact 112 and the main contact 110 is/are depressed, the processing unit 32 is programmed to accept the input from the sub-contact 112 and displays the character on the display 31 as depicted by the symbol on the sub-contact 112 .
[0022] Referring to FIG. 6 , a method of character inputs in the electronic device 30 is disclosed. When the character input procedure is started, in step S 40 , the electronic device 30 defaults to the first input mode then goes to step S 41 . In step S 41 , the electronic device 30 receives input signal from a combo key 15 , then goes to step S 42 . In step S 42 , the electronic device 30 detects whether the function key 16 , 17 is depressed. If the function key 16 or the function key 17 is depressed, goes to step S 45 ; else, goes to step S 43 . In step S 43 , the electronic device 30 detects whether the main contact 110 of the combo key 15 is depressed. If the main contact 110 is depressed, goes to step S 44 , else, goes to step S 41 . In step S 44 , the electronic device 30 displays the primary icon (i.e., the number) indicated by the main contact 110 on the display 31 , then goes to step S 41 . In step S 45 , the electronic device 30 shifts to the second input mode, then goes to step S 46 . In step S 46 , the electronic device 30 receives input signal from a combo key 15 , then goes to step S 47 . In step S 47 , the electronic device 30 detects whether the function key 16 , 17 is depressed. If the function key 16 or the function key 17 is depressed, goes to step S 40 ; else, goes to step S 48 . In step S 48 , the electronic device 30 detects whether the sub-contact 111 or the sub-contact 12 is depressed. If the sub-contact 111 or the sub-contact 12 is depressed, goes to step S 50 ; else goes to step S 49 . In step S 49 , the electronic device 30 displays the secondary icon (i.e., the alphabet letter) indicated by the main contact 110 on the display 31 , then goes to step S 46 . In step S 50 , the electronic device 30 displays the secondary icon (i.e., the alphabet letter) indicated by the sub-contact 111 or the sub-contact 112 on the display 31 , then goes to step S 46 .
[0023] Referring to FIG. 7 , another embodiment of a keypad used in the electronic device 30 is disclosed. The keypad 20 includes four key rows 21 , 22 , 23 , 24 . Each key row includes three combo keys 25 . Each combo key 25 includes a main contact 210 and two sub-contacts 211 , 212 . The two sub-contacts 211 , 212 are connected to each other and further enclose a main contact of the combo key. Other features of the keypad 20 are similar to keypad 10 mentioned above. Description to them is omitted here.
[0024] Moreover, it is to be understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.
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An apparatus for character input is disclosed. The apparatus includes a keypad and a processing unit. The keypad comprises a plurality of combo keys. Each combo key includes a main contact and at least one sub-contact adjacent to the main contact, the main contact and the sub-contact respectively have at least one icon representing a character. The processing unit receives a press operation on the keypad and inputting a corresponding character. The keypad of the apparatus is compact in size while character input on the keypad is conveniently.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related to a non-volatile memory storage device, and more particularly to a non-volatile memory storage device with boosted supply voltage and signal level.
[0003] 2. Description of Related Art
[0004] Non-volatile memory storage apparatus has become smaller and smaller, such as memory card and the application thereof has become wider and wider, for example, it has gradually adopted by the portable device. For matching to the requirement of the portable device, such as mobile phone, the volume of the memory storage device becomes thinner, shorter and smaller and the power consumption is also reduced for satisfying the requirements of reducing product volume and elongating the operating time of battery. Therefore, in some new products, the power supply voltage and interface signal level of the memory device are reduced.
[0005] For conforming to the low supply voltage, in the prior art, a controller having an operating voltage conforming to the supply voltage of the host device has to be used and also a non-volatile memory with low operating voltage has to be adopted as the storage medium. That is to say, both the operating voltage of the non-volatile memory storage medium and the memory interface signal level of the controller are equal to or slightly lower than the supply voltage, which is provided by the host device to the storage device. However, due to the voltage limitation, this kind of non-volatile memory storage device with low supply voltage has to adopt non-volatile memory with low supply voltage which is not popular and has lower capacity so that it may cause the maximum capacity of the non-volatile memory storage device with low supply voltage to become lower and also cause an increased cost.
[0006] Please refer to FIG. 1 which is a functional block diagram showing the conventional low voltage non-volatile memory storage device. Because the power adjusting circuit 11 can not boost the voltage level and only has functions of voltage stabilization and surge suppression for providing a stable internal operating voltage V IO to the non-volatile memory 13 and the controller 15 , the internal operating voltage V IO is approximately equal to or lower than the external supply voltage V S and the internal interface signal level V INT is also approximately equal to the external interface signal level V EXT . Therefore, this kind of non-volatile memory storage device 1 with lower supply voltage, as described above, has a smaller capacity and a higher cost.
[0007] For overcoming this problem, the present invention provides the non-volatile memory storage device with low supply voltage with functions of supply voltage boosting and signal level transformation such that the non-volatile memory adopting a normal operating voltage can be used as the storage medium for reducing the cost of the storage device and also increasing the storage capacity.
SUMMARY OF THE INVENTION
[0008] For achieving the purpose of adopting a non-volatile memory whose operating voltage is higher than the supply voltage as the storage medium, the present invention provides a voltage booster in the storage device so that the supply voltage can be boosted up to the operating voltage level of the non-volatile memory. Then, because the interface signal level of the non-volatile memory is boosted due to the operating voltage thereof, the memory interface signal level of the controller has to be cooperatively boosted for avoiding the memory interface of the controller from interfacing to a high potential signal source but maintaining at a lower signal level and from resulting in the non-volatile memory not correctly identifying the signal. At this time, the host interface signal level of the controller connected to the host device may still use the supply voltage of the host device to be the reference level so as to avoid the controller from not correctly identifying the high potential signal outputted by the host device or avoid the high potential signal outputted by the controller from exceeding the limited range of the host device (generally, the upper limitation is the supply voltage) due to the interface signal level be higher than the host interface supply voltage.
[0009] Therefore, the present invention provides a non-volatile memory storage device including a supply voltage booster for receiving an external voltage, boosting thereof and then outputting an internal voltage; a non-volatile memory storage unit for receiving the internal voltage and providing a storage of digital information; and a controller, wherein the controller includes a host device interface unit electrically connected to a host device, receiving the external voltage and transmitting an external signal between the host device and thereof, wherein the voltage level of the external signal is conformed to the external voltage; and a non-volatile memory interface unit electrically connected to the non-volatile memory storage unit, receiving the internal voltage and transmitting an internal signal between the non-volatile memory storage unit and thereof, wherein the voltage level of the internal signal is conformed to the internal voltage.
[0010] The present invention further provides a controller for a non-volatile memory storage device with dual interface signal level, characterized in that the controller includes a non-volatile memory interface unit connected to a non-volatile memory storage unit for boosting a signal level between the controller and the non-volatile memory storage unit up to an operating voltage of the non-volatile memory storage unit; and a host device interface unit connected to a host device for conforming a signal level between the controller and the host device to a supply voltage of the non-volatile memory storage device.
[0011] The present invention further provides a non-volatile memory storage device including a non-volatile memory storage unit and a controller, wherein the controller includes a supply voltage booster for receiving an external voltage, boosting thereof and then outputting an internal voltage and for providing the internal voltage to the non-volatile memory storage unit; a host device interface unit electrically connected to a host device, receiving the external voltage and transmitting an external signal between the host device and thereof, wherein the voltage level of the external signal is conformed to the external voltage; and a non-volatile memory interface unit electrically connected to the non-volatile memory storage unit, receiving the internal voltage and transmitting an internal signal between the non-volatile memory storage unit and thereof, wherein the voltage level of the internal signal is conformed to the internal voltage.
[0012] The present invention further provides a controller for a non-volatile memory storage device with boosted supply voltage and signal level, characterized in that the controller includes a non-volatile memory interface unit connected to a non-volatile memory storage unit for boosting a signal level between the controller and the non-volatile memory storage unit up to an operating voltage of the non-volatile memory storage unit; a supply voltage booster for boosting a supply voltage of the non-volatile memory storage device up to the operating voltage of the non-volatile memory storage unit so as to supply thereof to the non-volatile memory interface unit and the non-volatile memory storage unit; and a host device interface unit connected to a host device for conforming a signal level between the controller and the host device to the supply voltage of the non-volatile memory storage device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing aspects and many of the attendant advantages of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0014] FIG. 1 is a functional block diagram showing a conventional low voltage non-volatile memory storage device;
[0015] FIG. 2 is a functional block diagram showing a non-volatile memory storage device with boosted supply voltage and signal level;
[0016] FIG. 3 is a functional block diagram showing a controller for non-volatile memory storage device with dual-interface signal level;
[0017] FIG. 4 is a functional block diagram showing a non-volatile memory storage device having boosted supply voltage and signal level and adopting integration controller; and
[0018] FIG. 5 is a functional block diagram showing a controller for a non-volatile memory storage device with boosted supply voltage and signal level.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] In the prior art, the host device supplies power to the non-volatile memory storage device, and the supply voltage is lower than the internal operating voltage of the non-volatile memory in the non-volatile memory storage device. However, according to the present invention, as shown in FIG. 2 , which shows a functional block diagram of a non-volatile memory storage device with boosted supply voltage and signal level, through the supply voltage booster 21 boosting the level of the external supply voltage V S up to the internal operating voltage V IO , which conforms to the operation requirement of the non-volatile memory storage unit 23 , the non-volatile memory storage unit 23 still can operate normally.
[0020] Because the controller 25 has to interface with the host device 3 and the non-volatile memory storage unit 23 simultaneously, the signal reference voltage Vext_ref of the host device interface unit 251 will be the external supply voltage V S and the signal reference voltage Vext_ref of the non-volatile memory interface unit 253 will be the internal operating voltage V IO , so that the internal operating voltage V IO is higher than the external supply voltage V S . Then, for correctly and stably identifying, by the two parties of signal transmission, the high potential signals of the voltage level V EXT of an external signal between the controller 25 and the host device 3 and the voltage level V INT of an internal signal between the controller 25 and the non-volatile memory storage unit 23 , these two sets of reference power sources inside the controller 25 have to be separated independently so as to have a dual-interface installation with the host device interface 251 and the non-volatile memory interface unit 253 , wherein the host device interface unit 251 produces the external signal according to the external supply voltage V S and the non-volatile memory interface unit 253 processes the internal signal in accordance with the internal operating voltage V IO . Furthermore, because the internal operating voltage V IO is higher than the external supply voltage V S , the voltage level V INT of the internal signal is larger than the voltage level V EXT of the external signal.
[0021] In the above-described non-volatile memory storage device 2 , a supply voltage booster 21 receives an external supply voltage V S , boosts thereof, and then outputs an internal operating voltage V IO . The non-volatile memory storage unit 23 receives the internal operating voltage V IO , provides the storage of digital information and includes at least a non-volatile memory. Then, the controller 25 includes a host device interface unit 251 which is electrically connected to the host device 3 for receiving the external voltage V S and transmitting an external signal, which conforms to the external supply voltage V S , between the host device 3 and thereof, wherein the voltage level V EXT of the external signal is conformed to the external voltage V S . On the other hand, the non-volatile memory interface unit 253 is electrically connected to the non-volatile memory storage unit 23 for receiving the internal voltage V IO and transmitting an internal signal, which conforms to the internal operating voltage V IO , between the non-volatile memory storage unit 23 and thereof, wherein the voltage level of the internal signal V INT is conformed to the internal voltage V IO . Therefore, the purpose of using a non-volatile memory which adopts an operating voltage higher than the supply voltage as a storage medium is achieved.
[0022] Furthermore, the controller 25 with dual interface signal level will be discussed. Please refer to FIG. 3 which shows a functional block diagram of a controller for a non-volatile memory storage device with dual interface signal level. Following the description above, the controller 25 utilizes a non-volatile memory interface unit 253 to connect to a non-volatile memory storage unit 23 , and further, the non-volatile memory interface unit 253 is mainly used to boost a signal level between the controller 25 and the non-volatile memory storage unit 23 up to the internal operating voltage V IO of the non-volatile memory storage unit 23 . The host device interface unit 251 is connected to the host device 3 for conforming a signal level between the controller 25 and the host device 3 to the external supply voltage V S of the non-volatile memory storage device 2 . Moreover, in the controller 25 , it further includes utilizing an embedded micro-processor 255 to execute a control program; utilizing a code memory 256 to store codes required in executing the control program; utilizing a data memory 257 to temporally store the data related to the control program; and utilizing a data buffer unit 258 to temporally store the data exchanged between the host device 3 and the non-volatile memory storage unit 23 when the host device 3 accesses the non-volatile memory storage device 2 . In addition, the power adjusting circuit 254 may receive the external supply voltage V S for providing the operating voltage required for relative elements.
[0023] Furthermore, the non-volatile memory storage device 2 according to the present invention further includes a substrate for mounting the supply voltage booster 21 , the controller 25 and the non-volatile memory storage unit 23 thereon so as to achieve mutual transmissions of corresponding signals for each element through an electrical conductivity of the substrate and for mounting an electrical conductive interface thereon so as to connect to the host device 3 . Besides, the device 2 further includes a sealing package for packaging elements in the non-volatile memory storage device 2 but leaving the electrical conductive interface exposed for connecting to the host device 3 , wherein the substrate can be a printed circuit board.
[0024] Please refer to FIG. 4 which is a functional block diagram showing a non-volatile memory storage device having boosted supply voltage and signal level and adopting integration controller. The non-volatile memory storage device includes a non-volatile memory storage unit 43 and a controller 45 . The non-volatile memory storage unit includes at least a non-volatile memory. The controller 45 includes a supply voltage booster 451 for receiving an external voltage V S provided by a host device 5 , boosting the external voltage V S and then outputting an internal voltage V IO and for providing the internal voltage V IO to the non-volatile memory storage unit 43 . The controller 45 further includes a host device interface unit 453 electrically connected to a host device 5 for receiving the external voltage V S and transmitting an external signal, whose voltage level V EXT conforms to the external supply voltage V S , between the host device 5 and thereof. In addition, in the controller 45 , a non-volatile memory interface unit 455 electrically connected to the supply voltage booster 451 is also utilized in the controller 45 for receiving the internal voltage V IO and transmitting an internal signal, whose voltage level is conformed to the internal voltage V IO , between the non-volatile memory storage unit 43 and thereof.
[0025] Because the internal operating voltage V IO should be larger than the external supply voltage V S of the host device 5 , the controller 45 has to utilize a dual-reference-potentials installation with the host device interface unit 453 and the non-volatile memory interface unit 455 for simultaneously interfacing with the host device 5 and the non-volatile memory interface unit 455 . At this time, the signal reference voltage Vext_ref of the host device interface unit 453 is used as the external supply voltage V S and the signal reference voltage Vext_ref of the non-volatile memory interface unit 455 is used as the internal operating voltage V IO , so that the internal operating voltage V IO is higher than the external supply voltage V S . For correctly and stably identifying, by the two parties of signal transmission, the high potential signals of the voltage level V EXT of an external signal between the controller 45 and the host device 5 and the voltage level V INT of an internal signal between the controller 45 and the non-volatile memory storage unit 43 , these two sets of reference power sources inside the controller 45 have to be separated independently so as to have a dual-reference-potentials installation with a host device interface 451 and a non-volatile memory interface unit 453 , wherein the host device interface unit 453 may produce the external signal according to the external supply voltage V S so as to conform the voltage level V EXT of the external signal to the external supply voltage V S , and the non-volatile memory interface unit 455 may process the internal signal in accordance with the internal operating voltage V IO . Furthermore, because the internal operating voltage V IO is higher than the external supply voltage V S , the voltage level V INT of the internal signal is larger than the voltage level V EXT of the external signal.
[0026] Continuously, the controller 45 for integrating boosted supply voltage and signal level is further discussed as shown in FIG. 5 which shows a functional block diagram of a controller for a non-volatile memory storage device with boosted supply voltage and signal level. Following the description above, in the controller 45 , the non-volatile memory interface unit 455 is connected to a non-volatile memory storage unit 43 for boosting a signal level between the controller 45 and the non-volatile memory storage unit 43 to an operating voltage V IO of the non-volatile memory storage unit 43 , and the host device interface unit 453 is connected to the host device 5 for conforming a signal level between the controller 45 and the host device 5 to the supply voltage V S of the non-volatile memory storage device 4 , wherein the power adjusting circuit 456 is used to receive the supply voltage V S and transmit the processed supply voltage V S to the supply voltage booster 451 , and then the supply voltage booster 451 may boost thereof up to an internal operating voltage V IO . In addition, the controller 45 further includes an embedded micro-processor 457 for executing a control program; a code memory 458 for storing codes required in executing the control program; a data memory 459 for temporally storing data related to the control program; and a data buffer unit 454 for temporally storing the data exchanged between the host device 5 and the non-volatile memory storage unit 43 when the host device 5 accesses the non-volatile memory storage device 4 .
[0027] Furthermore, the non-volatile memory storage device 4 according to the present invention further includes a substrate for mounting the controller 45 and the non-volatile memory storage unit 43 thereon so as to achieve mutual transmissions of corresponding signals for each element through an electrical conductivity of the substrate and for mounting an electrical conductive interface thereon so as to connect to the host device 5 . Besides, the device 4 further includes a sealing package for packaging elements in the non-volatile memory storage device 4 but leaving the electrical conductive interface exposed for connecting to the host device 5 , wherein the substrate can be a printed circuit board.
[0028] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A non-volatile memory storage device with functions of boosting supply voltage and signal level can adopt a non-volatile memory having an operating voltage higher than the supply voltage provided by the host device as a storage medium. The non-volatile memory storage device includes a supply voltage booster, a non-volatile memory storage unit and a controller. The supply voltage booster boosts the lower supply voltage provided by the host device up to the higher operating voltage of the non-volatile memory. The controller adjusts the interface signal to a proper interface signal level by cooperating with the supply voltage and the operating voltage so as to avoid the interface from damage owing to an over high signal level or avoid the non-volatile memory unit from not correctly receiving signal due to an over low signal level.
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This application claims the benefit of U.S. Provisional Application No. 60/012,417 filed Feb. 28, 1996, entitled LIGHT BLUE GLASSWARE, by W. Duane Amundson, Jr.
FIELD OF THE INVENTION
Transparent, colored glasses having a soda lime silicate base, and glassware produced therefrom.
BACKGROUND OF THE INVENTION
Glass ovenware was introduced commercially about 1915 under the trademark PYREX. This glassware was clear, water white, and molded from a borosilicate glass.
Subsequently, use of glassware became wide spread for the preparation and serving of food. As this occurred, a desire for glassware having color developed.
One method of meeting this need was with opal ware. This glassware is rendered opaque by development of light scattering particles dispersed in the glass. Opal ware was used as such, was colored by colorants added to the glass batch, or was given a colored coating, for example, an enamel applied to the surface of the ware. The latter procedure was of particular interest because it permitted either solid color or patterns.
The development of opal ware led to a need for increased mechanical strength as well as heat resistance. It was found that this need could be met by tempering the opal ware. Tempering is a procedure of glass treatment in which the surface of a glass article is placed in compression, thereby increasing the force necessary to induce fracture. Numerous methods have been described and used to temper glass articles. These include thermal treatment by chilling from an elevated temperature, and chemical treatment by ion exchange.
The tempering treatment can also be employed to strengthen, and render thermally resistant, transparent glassware, either plain or colored, produced with a soda lime silicate base glass. This glass base has a significantly less expensive batch, and is easier to melt than the borosilicate glasses originally employed.
U.S. Pat. No. 5,204,293 (Aroundson, Jr. et al.) describes a family of transparent, soda lime silicate glasses having a burgundy color. The glass compositions consist essentially of 0.3-2.2 percent by weight manganese oxide in a soda lime silicate base glass. The glass has impurity levels for NiO and Fe 2 O 3 not exceeding 100 parts per million (ppm) and 500 ppm, respectively.
The present invention arose in the course of developing a set of three transparent, solid color bowls having such light colors as to be termed blush colors. The color intensity is so low that the color is barely visible in a thin wall section. The color becomes more like a highlight being visible in thicker rim and foot areas, as well as through an edge. The invention is concerned directly with a member of the set having a light blue color.
A primary purpose of the invention then is to provide a transparent, soda time silicate glass embodying an acceptable light blue color and a bowl molded therefrom. Another purpose is to provide a complete line of such glassware for use in preparation and serving of food. A further purpose is to provide such glassware that can be strengthened and rendered heat resistant by tempering. Another purpose is to provide a combination of colorants that can be melted as part of a glass batch, or can be incorporated in an uncolored base glass by a color cell procedure. Such a procedure involves adding colorant to a glass as the molten glass passes through a forehearth.
SUMMARY OF THE INVENTION
The invention resides in part in a transparent glass exhibiting a light blue color and having a composition, as analyzed, consisting essentially of 100-250 ppm copper oxide in conjunction with 5-15 ppm cobalt oxide, calculated as Co 3 O 4 , in a soda lime silicate base glass, the glass containing as impurities no more than 500 ppm MnO 2 and 500 ppm Fe 2 O 3 .
The invention further resides in a tempered glass article that is useful in the preparation and serving of food, and that is molded from the glass just described.
BRIEF DESCRIPTION OF THE DRAWINGS
The single FIGURE in the accompanying drawing is a graphical representation of the invention in terms of x and y color coordinates.
PRIOR ART
Literature of possible relevance is set forth in an accompanying document.
DESCRIPTION OF THE INVENTION
A key feature of the present invention resides in discovery of a certain glass colorant combination. This colorant combination provides a relatively specific, light blue color in a soda lime silicate base glass.
The term "soda lime silicate glass" is generally understood in the glass art to mean glasses having compositions consisting essentially of 70-75% SiO 2 , 5-15% Na 2 O and 5-15% CaO. Minor mounts of other oxides may optionally be present, such as alumina as a stabilizer and antimony as a fining agent.
The single FIGURE in the accompanying drawing is a graphical representation defining in terms of x and y color coordinates, the color feature of the invention. The color coordinates refer to, and are based on, Illuminant C in accordance with the CIE color coordinate system. The x coordinates are plotted on the horizontal axis. The y coordinates are plotted on the vertical axis.
The rectangle ABCDA encompasses coordinate values that represent the area within which a blue color can be obtained that is suitable for present purposes. x and y coordinate values for the points A, B, C and D are as follows:
______________________________________ x y______________________________________A 0.3080 0.3165B 0.3092 0.3153C 0.3072 0.3133D 0.3060 0.3145______________________________________
A smaller area was established as a target, or preferred area, for introduction of a colorant by a color cell procedure. This preferred area is designated as EFGH in the drawing and has color coordinates as follows:
x=0.3081-0.3070
y=0.3155-0.3142
CAP Y=88.7-87.8.
The desired light blue color is obtained only with a combination of 100-250 ppm copper oxide (CuO) and 5-15 ppm cobalt oxide (Co 3 O 4 ) as glass colorants. Neither oxide alone produces an acceptable light blue color. It was observed that cobalt oxide is the more sensitive of the two colorants. Thus, within the indicated limits, the cobalt oxide has the dominant effect on color. Hence, it must be more closely monitored in order to obtain a consistent color in ware.
The light blue color of the invention may be obtained in a reasonably pure form with the colorant combination of copper and cobalt oxides. However, care must be taken to observe the indicated composition limits. Thus, an excess of cobalt oxide tends to push the color toward a deep blue. Likewise, too much copper oxide tends to produce a green cast in the glass article.
Care must also be taken to either avoid, or carefully limit, the presence of other colorants that may produce either an off-color or a grayish tint. In order to use cullet from a glass containing manganese oxide, it has been found that this oxide may be tolerated in amounts up to about 500 ppm. However, it is preferred to keep the content below 400 ppm since larger amounts tend to have an undesirable effect on the color. Chrome (Cr 2 O 3 ) and molybdenum oxide (MoO 3 ) should each be kept below about 10 ppm, while nickel oxide (NiO) should be kept below about 30 ppm, to avoid undesirable color effects.
Iron oxide is almost inevitably present as an impurity. A small amount, for example on the order of 250 ppm, is useful for heat retention in the glass melt during the melting operation. However, this oxide should not exceed 500 ppm, and preferably is maintained under 400 ppm.
SPECIFIC EMBODIMENTS
A commercially melted, water white, soda lime silicate glass was selected as a base glass for development purposes. A typical analysis of this glass, in approximate weight percent, is:
______________________________________SiO.sub.2 75.5 CaO 9.5Na.sub.2 O 12.9 Al.sub.2 O.sub.3 1.7K.sub.2 O 0.4 Sb.sub.2 O.sub.3 0.02Li.sub.2 O 0.02 Fe.sub.2 O.sub.3 290 ppm.______________________________________
Antimony oxide functions as a fining agent and alumina as a stabilizer. K 2 O, Li 2 O and Fe 2 O 3 are present only because they occur in soda and silica raw materials.
Batches were prepared based on this commercial glass composition. Various mounts of colorants were added to the batches to provide a range of glass colors for establishing color feasibility and color selection. Crucible melts were made in silica crucibles in a gas-fired furnace that was held at 1500° C. for 4 hours. The melts were poured in molds to form patties for test purposes.
TABLE I sets forth in parts per million (ppm) the colorant amounts hatched in several melts, together with the color coordinates measured on samples of the batch melts. The colorants added were copper oxide alone, or in combination with cobalt oxide. The color coordinates were measured in terms of the CIE system.
TABLE I______________________________________CuO Co.sub.3 O.sub.4 MnO.sub.2Ex. (ppm) (ppm) (ppm) x y Cap Y______________________________________1 100 5 0.3088 0.3155 90.612 100 10 0.3076 0.3142 89.073 100 15 0.3067 0.3133 88.094 175 5 0.3089 0.3156 89.945 175 10 0.3075 0.3143 88.916 175 15 0.3061 0.3129 87.857 250 5 0.3087 0.3156 89.788 250 10 0.3073 0.3143 98.449 250 15 0.3061 0.3131 86.7910 100 0 0 0.3105 0.3171 90.7411 200 0 0 0.3102 0.3169 90.7312 175 5 350 0.3078 0.3145 88.2513 175 10 350 0.3066 0.3134 86.6914 175 5 700 0.3089 0.3155 85.8215 175 10 700 0.3090 0.3155 82.28______________________________________
Subsequently, with these crucible melts as a guide, a trial run was carded out on glass from a commercial unit melting the water white base glass. Colorant was added in increasing amounts to the glass in a forehearth via a color cell system. In this procedure, a granulated, sintered color concentrate was added to the glass melt in the forehearth. Samples were taken periodically and 4 mm thick test pieces were prepared for measurement of x and y coordinates as well as colorant contents.
On the basis of the color samples thus produced, a set of limits for preferred analyzed colorant content and x, y and CAP Y coordinates was established. These were:
TABLE II______________________________________CuO (ppm) Co.sub.3 O.sub.4 (ppm) x y Cap Y______________________________________Light 160 7 0.3081 0.3155 88.7Preferred 180 8 0.3075 0.3148 88.3Dark 190 10 0.3070 0.3142 87.8______________________________________
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A transparent glass exhibiting a blue color, the glass, as analyzed, consisting essentially of 100-250 ppm copper oxide in conjunction with a co-colorant of 5-15 ppm cobalt oxide, calculated as Co 3 O 4 , in a soda lime silicate base glass that contains as impurities no more than 500 ppm MnO 2 and 500 ppm Fe 2 O 3 .
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FIELD
[0001] The present invention relates to an elevator installation in which at least one elevator car and at least one counterweight are moved in opposite sense in an elevator shaft, wherein the at least one elevator car and the at least one counterweight run along guide rails and are carried by one or more support means. The or each support means is or are guided by way of a drive pulley of a drive unit which has a drive brake. Moreover, the elevator installation comprises a safety circuit which, inter alia, activates the drive brake in the case of an emergency and includes bridging-over of the door contact so that on opening of the doors the safety circuit remains closed. The present invention relates particularly to the safety circuit.
BACKGROUND
[0002] In conventional elevator installations electromechanical switches are employed for bridging over the door contacts. Particularly in the case of elevator installations in office buildings, however, the number of journeys of the elevator car can be more than 1,000 per working day, in which case bridging-over of the door contacts takes place twice in each journey. Thus, a number of approximately 520,000 switchings per year results for the electromechanical switches, This number is so high that the electromechanical switches become the principal limiting factor for the reliability of the bridging-over of the door contacts.
[0003] Due to the high number of switching actions and the high demands the bridging-over of the door contacts is classified as a so-called high-demand safety function. In general, the Standard IEC 61508 defines high-demand safety functions as functions which in disturbance-free normal operation of the elevator installation switch on average more than once per year, whereas by low-demand safety functions there are designated such functions which are provided only for emergency situations of the elevator installation or only for an emergency operation of the elevator installation, in which a disturbance is present and on average switch less frequently than once per year.
[0004] A significant element of this International Standard IEC 61508 is the determination of the safety requirement stage (Safety Integrity Level—SIL; there are SIL1 to SIL4). This is a measure for the necessary or achieved risk-reducing effectiveness of the safety functions, wherein SIL1 has the lowest demands. Provided as essential parameter for the reliability of the safety function of apparatus or installations are the calculation bases for PFH (probability of dangerous failure per hour) and PFD (probability of dangerous failure on demand). The first parameter PFH relates to high-demand systems, thus to those with a high demand rate, and the second parameter PFD to low-demand systems, the time of their service life being virtually equal to non-actuation. The SIL can be read off from these parameters.
[0005] A further definition, which can be found in technical media on the basis of this Standard (IEC 61508-4, section 3.5.12), of the low-demand mode of operation (Low-Demand Mode) and the high-demand mode of operation (High-Demand Mode or continuous operating mode) specifies the distinction thereof not on the basis of the low or high (continuous) demand rate, but in the following terms: A (low-demand) safety function, which operates in demand mode, is executed only on demand and brings the system to be monitored into a defined safe state. The executive elements of this low-demand safety function have no influence on the system to be monitored prior to occurrence of a demand for the safety function. Thereagainst, a (high-demand) safety function operating in continuous mode, always keeps the system, which is to be monitored, in its normal safe state. The elements of this high-demand safety function thus constantly monitor the system to be monitored. Failure of the elements of this (high-demand) safety function has the direct consequence of a risk if no further safety-related systems or external measures for risk reduction are effective. Moreover, a low-demand safety function is present when the demand rate is not more than once per year and not greater than twice the frequency of the routine inspection. A high-demand safety function or continuous safety function is, thereagainst, present when the demand rate is more than once per year or greater than twice the frequency of the routine inspection (see also IEC 61508-4, section 3.5.12).
SUMMARY
[0006] The object of the present invention is to propose a safety circuit for an elevator installation which embraces a more reliable and safer fulfilment of a frequently switching high-demand safety function such as, for example, the bridging-over of the door contacts and thus enhances safety, as well as also cost efficiency and minimized maintenance, of the entire elevator installation.
[0007] Fulfilment of the object consists at the outset in the selective replacement by electronic semiconductor switches of those conventional electromechanical switches which are subject to a high number of switchings (high-demand safety function). Such a high-demand safety function is, for example, the bridging-over of the door contacts, but other safety functions which are switched in disturbance-free normal operation also come into consideration and, in particular, those which are frequently switched.
[0008] Such semiconductor switches, for example with metal-oxide semiconductor field-effect transistors (MOSFET: Metal-Oxide Semiconductor Field-Effect transistor), are based generally on transistors which withstand millions of switching cycles per day. The only disadvantage is the tendency thereof to cause a short-circuit on failure, which has the consequence of a permanent bridging-over of all door contacts. In other words, if for reasons of redundancy two semiconductor switches (in order to fulfill safety category SIL2) for bridging over the door contacts are for preference provided and these two semiconductor switches should fail due to a short-circuit, the high-risk situation arises that the elevator car and the counterweight can be moved with open shaft and/or car doors, because the semiconductor short-circuit simulates closed doors.
[0009] In general, for avoidance or detection of a short-circuit in a semiconductor switch complicated and cost-intensive solutions for a so-called failsafe capability have been proposed.
[0010] The published specification EP-A2-1 535 876 discloses a drive which is connected with an electronic device having power semiconductors, wherein provided between the drive and the electronic device is at least one main contactor which is connected with a safety circuit comprising door switches connected in series. These serially connected door switches are in turn bridged over by switches on opening of the doors. This published specification thus does indeed disclose the use of semiconductors/power-semiconductors in an electronic device of the drive, but not within the safety circuit, as well as also no failsafe solution for avoidance of the tendency of semiconductors to short-circuit, but rather retention—which serves for avoidance of noise—of the at least one main contactor and checking of the latter by a time element and/or a counter.
[0011] According to the invention, in the case of a safety circuit in accordance with the present application an individual failsafe solution for the respective electronic semiconductor switches is not provided, but another electromechanical safety relay, which is present in any case, is—for the avoidance or detection of a possible short-circuit—incorporated in one of the electronic semiconductor switches. In this regard it is intended in accordance with the invention that in the case of a short-circuit in one of the electronic semiconductor switches, which according to the invention and for reasons of redundancy (safety category SIL2) are provided in double form for bridging-over of the door contacts, for the moment still nothing happens. If, however, the second electronic semiconductor switch also fails—which due to possible overload peaks can take place more rapidly—there is intervention not by an individual failsafe solution provided for that purpose or an extra safety relay provided for that purpose in order to open the safety circuit, but by at least one electromechanical safety relay which is present in any case and which would open the safety circuit within the scope of another safety function if an irregularity were to be present within this latter safety function. Alternatively, opening of the safety circuit can also take place on failure of the first semiconductor switch.
[0012] This—at least one—other electromechanical safety relay of the first safety-relevant function of the elevator installation is preferably provided for a so-called low-demand safety function, i.e. for a safety function which is exposed to few switching processes in that, for example, it switches only in the case of emergency situations outside normal operation (see the definition of Low-Demand Mode and High-Demand Mode in the above paragraphs).
[0013] According to the invention another form of safety relay can be, for example, a so-called ETSL relay circuit, wherein ETSL stands for Emergency Terminal Speed Limiting, thus for a speed-dependent emergency-situation shaft-end retardation control. Such ETSL relay circuits are known from the prior art. This ETSL relay circuit is a so-called low-demand safety component which is not used in normal operation. It comes into function only extremely rarely, namely only if the elevator car should happen to move out of its normal range. This ETSL relay circuit is electromechanical, i.e. it comprises not semiconductors, but relay contacts and electromechanical safety relays and according to the invention is, in addition to its original shaft-end retardation control function, incorporated into the monitoring of the semiconductor switches. These semiconductor switches are according to the invention used for a high-demand safety function, for example for bridging-over of the door contacts, but expressed more generally for a series connection of contacts which are closed in the case of disturbance-free normal operation, but which are opened in the case of specific operating conditions and then can be bridged over so that the entire safety circuit remains active.
[0014] In other words, the elements of the electromechanical relay circuit—or at least parts thereof—are in accordance with the invention used for the purpose of opening the safety circuit in the case of a short-circuit of one or both semiconductor switches.
[0015] According to the invention monitoring of the semiconductor switches takes place by means of a monitoring circuit which is processor-controlled. If the monitoring reveals that the semiconductor switches are short-circuited, the processor is or processors are in accordance with the invention in a position of letting the safety circuit of the elevator installation open preferably by way of another electromechanical relay circuit present in any case, for example an ETSL relay circuit.
[0016] In a first solution it is provided that at least one processor on the one hand is in a position of controlling the semiconductor switches (for example for bridging over the door contacts) and at the same time the monitoring of the semiconductor switches. On the other hand, the at least one processor is in accordance with the invention at the same time in a position, in the case of a short-circuit detected by way of the monitoring, of providing direct control intervention at relay contacts again connected in series for that purpose or at one or more electromechanical safety relays of the other electromechanical relay circuit. In other words, it is preferred in accordance with the invention that the other relay circuit itself no longer has a possible individual processor and the above-mentioned at least one processor controls not only the semiconductor switches, but also the monitoring thereof and additionally also the original function of the electromechanical relay circuit.
[0017] Consequently, in the exemplifying case of the electromechanical relay circuit detecting the ETSL function of the elevator installation this means that the ETSL function no longer has any processors or any individual processors. The at least one processor for the semiconductor switches and the monitoring thereof also takes over the ETSL function. This merely requires appropriate lines and the corresponding connection with the processor now executing both safety-relevant functions and provides a considerable cost advantage.
[0018] However, as a further alternative it is also possible to make further use of the controlling processor or processors of the electromechanical relay circuit and to pass on the controlling processor or processors of the semiconductor switches for opening the safety circuit due to a short-circuit of the semiconductor switches to the controlling processor or processors of the electromechanical relay circuit.
[0019] Moreover, it would also be possible to make further use of the controlling processor or processors of the electromechanical relay circuit not to pass on to the controlling processor or processors of the electromechanical relay circuit the control command of the processors for the semiconductor switches for opening of the safety circuit, but to let the processors of the semiconductor switches intervene directly at the relay contacts or at electromechanical safety relays connected therewith.
[0020] As already mentioned, the bridging-over of the series connection of contacts can be a frequently switching high-demand function, for example the bridging-over of the door contacts which in accordance with the invention is carried out by semiconductor switches. However, notwithstanding this use of semiconductor switches the same level of safety as with electromechanical safety relays is achieved in that in the case of a failure (short-circuit) of the bridging-over of the door contacts use is preferably made of the ETSL safety relay or relays in order to re-open the safety circuit and avoid risky situations.
[0021] In order to achieve at least the same or an increased level of safety it is basically necessary to take into consideration only those electromechanical safety relays in the incorporation, in accordance with the invention, for bypassing a bridging-over—which is no longer functional due to a short-circuit—of the door contacts by means of semiconductor switches which with respect to their connections, design and level of safety (so-called SIL category, wherein SIL stands for Safety Integrity Level, see above) are provided for a safety function which cannot be bridged over by mechanical operation, i.e. the electromechanical safety relay has to be designed so that it at least covers a safety function which is of such fundamental importance that it can be bridged over only intentionally by manual operation or even can never be bridged over.
[0022] As already mentioned, the two conventional electromechanical relays for bridging over the door contacts are in accordance with the invention replaced by, for example, two MOSFETs. Moreover, in accordance with the invention the two MOSFETs are each monitored by a respective processor or microprocessor and a monitoring circuit or check circuit in that a voltage measurement is carried out at an input and an output of the MOSFETs separately for each channel. If one MOSFET or both MOSFETs should be damaged (which in the case of such switches usually means a short-circuit) the respective processor will recognize this state and open the ETSL relay contact or contacts. A further advantage is thus that it is even possible for both MOSFETs to be damaged at the same time; in this way, however, the device or the elevator installation always remains safe.
[0023] In addition, in accordance with the invention an indicating means is provided which supplies information if a short-circuit is bypassed in one of the semiconductor switches by one of the electromechanical safety relays or the contacts thereof.
[0024] The MOSFETs are normally always closed when the doors are open. Consequently, provision is made for the respective processor to briefly open the MOSFETs at a regular interval of a few seconds in order to check the voltage drop at the MOSFET without the safety relay of the safety circuit dropping out and thus the corresponding relay contact of the safety circuit opening. This switch-off period is in accordance with the invention short enough for the purpose of measurement of the voltage drop, but not of such length as to allow the relay of the safety circuit to drop out.
[0025] It remains open to an expert to realize the just-described checking not by means of measurement of voltage drop, but by means of measurement of amperage, preferably inductively and contactlessly.
[0026] The present invention thus presents a hybrid solution which economically combines the proven safety of electromechanical relays with the high level of reliability—particularly with respect to the number of switching cycles—of transistors.
[0027] A bridging-over connection in accordance with the invention thus comprises semiconductor switches preferably for frequently switching high-demand safety functions, such as, for example, the bridging-over of the door contacts, and a processor-controlled check circuit for these semiconductor switches as well as preferably incorporation of an electromechanical safety relay, which is normally responsible for another seldom-switching low-demand safety function, for bypassing the semiconductor switches in the case of a semiconductor short-circuit and opening of the safety relay.
[0028] Moreover, the safety circuit includes the usual features and switching arrangements appropriate to current elevator installations—not least due to the applicable standards—and familiar to an expert in the field of construction of elevator installations. Such features are, for example, the serial arrangement of all shaft door contacts, the similarly serial arrangement of the car door contact or contacts, the monitoring of the travel of the elevator car by limit switches (EEC—Emergency End Contact), the monitoring of the travel speed of the elevator car by sensors at the shaft end (ETSL), brake contacts and at least one emergency off-switch.
DESCRIPTION OF THE DRAWINGS
[0029] The invention is explained in more detail symbolically and by way of example on the basis of figures. The figures are described conjunctively and generally. The same reference numerals denote the same components and reference numerals with different indices indicate functionally equivalent or similar components.
[0030] FIG. 1 shows a schematic illustration of an exemplifying elevator installation;
[0031] FIG. 1 a shows a schematic illustration of the safety circuit of FIG. 1 ; and
[0032] FIG. 2 shows a schematic illustration of an arrangement in accordance with the invention of two semiconductor switches for bridging over a series connection of contacts, a monitoring circuit for these two semiconductor switches, an electromechanical relay circuit and the integration in accordance with the invention of this arrangement in a conventional safety circuit according to FIG. 1 or FIG. 1 a and the thus-resulting safety circuit according to the invention.
DETAILED DESCRIPTION
[0033] FIG. 1 shows an elevator installation 100 , for example in illustrated 2:1 support means guidance. An elevator car 2 is movably arranged in an elevator shaft 1 and is connected by way of a support means 3 with a movable counterweight 4 . In operation, the support means 3 is driven by means of a drive pulley 5 of a drive unit 6 , these being arranged in, for example, the uppermost region of the elevator shaft 1 in an engine room 12 . The elevator car 2 and the counterweight 4 are guided by means of guide rails 7 a or 7 b and 7 c extending over the shaft height.
[0034] The elevator car 2 can at a conveying height h serve an uppermost floor with floor door 8 , further floors with floor doors 9 and 10 and a lowermost floor with floor door 11 . The elevator shaft 1 is formed from shaft side walls 15 a and 15 b, a shaft ceiling 13 and a shaft floor 14 , on which a shaft floor buffer 19 a for the counterweight 4 and two shaft floor buffers 19 b and 19 c for the elevator car 2 are arranged.
[0035] The support means 3 is fastened at a stationary fastening point or support means fixing point 16 a to the shaft ceiling 13 and is guided parallelly to the shaft side wall 15 a to a support roller 17 for the counterweight 4 . From here it goes back again over the drive pulley 5 to a first deflecting or support roller 18 a and a second deflecting or support roller 18 b, looping under the elevator car 2 , and to a second stationary fastening point or support means fixing point 16 b at the shaft ceiling 13 .
[0036] A safety circuit 200 comprises on each of the floors 8 to 11 a respective shaft door contact 20 a to 20 d, which contacts are arranged in series in a shaft door circuit 21 . The shaft door circuit 21 is connected with a PCB (Printed Circuit Board) 22 which, for example, is arranged in the engine room 12 . The PCB 22 is connected by a connection 23 , which is to be understood only in symbolic terms, with the drive 6 or a drive brake 24 so that in the case of fault reports of the safety circuit 200 the drive of the drive unit 6 or the rotation of the drive pulley 5 can be stopped.
[0037] The connection 23 is to be understood only in symbolic terms because in reality it is significantly more complicated and as a rule includes the elevator control. It additionally comprises a relay 40 of the safety circuit 200 and connecting points 41 a and 41 b, Between the latter there is realized a shaft-end retardation control function 42 , which usually has two channels in order to fulfill the safety category SIL2, in that a first ETSL channel and a second ETSL channel are serially arranged in the safety circuit 200 . The two ETSL channels are symbolically illustrated as switches 31 a and 31 b, but are switching relays with switch contacts.
[0038] Not only the shaft doors have a shaft door circuit 21 for control of the opening of the shaft doors 21 , but in addition the elevator car 2 has a car door circuit 25 for control of the opening of two schematically indicated car sliding doors 27 a and 27 b. This car door circuit 25 comprises a car door contact 26 . Signals from the car door circuit 25 are conducted by way of a hanging cable 28 of the elevator car 2 to the PCB 22 , where they are included in the safety circuit 200 in series with the shaft door contacts 20 a to 20 d.
[0039] The elevator installation 100 further comprises a bridging-over connection 29 for the shaft door contacts 20 a to 20 d arranged in a series connection 43 and the similarly serially arranged car door contact 26 . The bridging-over connection 29 comprises switching relays which are arranged in parallel between two further connecting points 41 c and 41 d and the switch contacts of which are symbolically illustrated as switches 30 a and 30 b.
[0040] In FIG. 1 a the safety circuit 200 of the elevator installation 100 of FIG. 1 is illustrated separately so that the connections and switchings thereof are clearer. The shaft-end retardation control connection 42 and the door-contact bridging-over connection 29 are independent of one another; they are merely serially integrated in the safety circuit 200 .
[0041] In FIG. 2 it is illustrated how on the one hand a bridging-over connection 29 a according to the invention for bridging over the contacts 20 a to 20 d and 26 of FIGS. 1 and 1 a is executed between the connecting points 41 c and 41 d of the safety circuit 200 of FIG. 1 and how on the other hand an electromechanical relay circuit 42 a is arranged in accordance with the invention between the connecting points 41 a and 41 b of the safety circuit 200 of FIG. 1 , as well as how the bridging-over connection 29 a and the electromechanical relay circuit 42 a are in accordance with the invention connected together and thus a safety circuit 200 according to the invention and an elevator installation 100 according to the invention result. The electromechanical relay circuit 42 a is preferably represented by a relay circuit for performance of a low-demand safety function of the elevator installation 100 .
[0042] In order to take over a high-demand safety function such as, for example, the bridging-over function of the door contacts a microprocessor 34 c with a semiconductor switch or transistor 36 a is appropriately connected into a first circuit 300 a. The transistor 36 a is by way of example represented as MOSFET transistor, but other types of transistors are also suitable.
[0043] Also indicated is a monitoring circuit 37 a which is connected with an input 38 a and an output 39 a of the semiconductor switch 36 a. The processor 34 c controls the periodic cycles of measurement of the voltage or amperage at the input 38 a and output 39 a. The connecting point 38 a can obviously also be represented by the output of the semiconductor switch 36 a and the connecting point 39 a by the input of the semiconductor switch 36 a.
[0044] The bridging-over connection 29 a, with which—as apparent from FIGS. 1 and 1 a —all door contacts 20 a to 20 d, 26 are serially connected by way of the connecting points 41 c and 41 d, is of two-channel construction for reasons of redundancy or fulfilment of the SIL2 safety category. The second channel comprises, analogously to the first channel, a circuit 300 b, a semiconductor switch 36 b and a monitoring circuit 37 b for the semiconductor switch 36 b, which is connected with an input 38 b and an output 39 b of the semiconductor switch 36 b and is controlled by a microprocessor 34 d. The microprocessors 34 c and 34 d are connected together for a bidirectional signal exchange. It is also possible to provide more than two channels.
[0045] The microprocessor 34 c is additionally connected with an electromechanical relay 35 c, a change contact 32 c and a resistance 33 c of a first ETSL channel or, with omission of a possible ETSL processor, the remaining elements of an electromechanical relay circuit 42 a with relay contacts 31 c and 31 d. The microprocessor 34 d is in turn connected with an electromechanical relay 35 d, a change contact 32 d and a resistance 33 d of a second ETSL channel. These two ETSL channels guarantee the shaft-end retardation control function, which is thus to SIL2 safety category, wherein the retardation control connection 42 necessary for that purpose is connected between the connecting points 41 a and 41 b of the safety circuit 200 of FIG. 1 .
[0046] The shaft-end retardation control connection 42 used for the purpose according to the invention no longer has individual microprocessors, because the control of the retardation control connection 42 is carried out by means of the microprocessors 34 c and 34 d, in addition to the control of the bridging-over connection 29 a and in addition to the control of the monitoring circuits 37 a and 37 b.
[0047] Also optionally possible is an arrangement with a single microprocessor which controls not only the two illustrated channels of the bridging-over connection 29 a, but also the two illustrated channels of the electromechanical relay circuit 42 a and the retardation control connection 42 .
[0048] FIG. 2 schematically illustrates an exemplifying arrangement of a parallelly arranged two-channel bridging-over of door contacts connected in series (not only the shaft door contacts 20 a to 20 d, but also the car door contact 26 ) of the elevator installation 100 a, or in general a possible combined detection in accordance with the invention of a first safety-relevant function, preferably a low-demand safety function (for example the shaft-end retardation control ETSL) and a further safety-relevant function, preferably a high-demand safety function (for example the bridging-over of the door contacts).
[0049] If a check of the semiconductor switches 36 a and 36 b by means of the monitoring circuits 37 a and 37 b yields a defect or a short-circuit of one of the semiconductor switches 36 a and 36 b or both semiconductor switches 36 a and 36 b the microprocessor and/or microprocessors 34 c and/or 34 d is or are according to the invention in a position of controlling the conventional electromechanical safety relays 35 c and 35 d of the electromechanical relay circuit 42 a for opening of the safety circuit 200 . This takes place additionally to the intended original shaft-end retardation of the elevator car 2 , which the electromechanical relay circuit 42 a could originally exercise. This intended original safety function does not cease to apply due to the assumption of the opening function of the safety circuit 200 , preferably because the microprocessors 34 c and 34 d control not only the shaft-end retardation control connection of the elevator car 2 of the elevator installation 100 , but also the bridging-over connection 29 a with the semiconductor switches 36 a and 36 b as well as monitoring of the semiconductor switches 36 a and 36 b.
[0050] The bridging-over connection 29 a equipped with the semiconductor switches 36 a and 36 b comes into consideration not only for frequently switching high-demand functions, but also for any low-demand functions such as, for example, the EEC function, wherein EEC stands for Emergency End Contact, thus for a travel limitation of the elevator car 2 by means of limit switches beyond its normal travel path. The bridging-over connection 29 a, which according to the invention can be combined with an electromechanical relay circuit 42 a as disclosed, is also used, for example, for the braking function or for emergency evacuation.
[0051] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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A safety circuit in an elevator system includes at least one series connection of safety-relevant contacts that are closed during trouble-free operation of the elevator system, wherein in the case of certain operating conditions in which at least one contact is opened, the at least one contact can be bridged by semiconductor switches, and wherein the semiconductor switches are controlled by at least one processor and monitored by at least one monitoring circuit for short circuits. At least one electromechanical relay circuit, having relay contacts connected in series with the contacts of the bridged series connection can be controlled by the at least one processor and the bridgable series connection can be interrupted by the relay contacts in the case of short-circuiting of the semiconductor switches.
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This is a continuation of application Ser. No. 311,144 filed Oct. 13, 1981 U.S. Pat. No. 4,574,250.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of analog integrated filters and filtering methods, particularly filters utilizing switched capacitor techniques.
2. Prior Art
Substantial amounts of efforts have been expended in the development of circuitry and methods for the digitization of analog information for digital transmission. In order to achieve high quality audio application in analog-to-digital encoders and decoders, voiceband filters are required which must meet among other stringent requirements, stringent signal-to-noise ratios and power supply rejection. Degradation of monolithic filter performance has been a particular problem. In an integrated filter, the amount of power dissipation, supply rejection and signal-to-noise ratio is appreciably different than the amounts experienced in circuits comprised of passive or discrete active elements. In addition, integrated filters are subject to chip area limitations. However, in order to devise an economical and effective device in digital communications, it is indispensable that a circuit design and methodology, operable within the design limitations of an integrated circuit, be realized.
What is needed then is a circuit and method by which a combination of filter and analog-to-digital encoder, and of filter and digital-to-analog decoder can be devised in an integrated circuit to meet the stringent requirements with respect to noise and power supply rejection imposed upon the circuit by voice transmission standards and still meet the power dissipation and chip area limitations inherent in integrated circuit design.
BRIEF SUMMARY OF THE INVENTION
The invention is a differential amplifier, having internal common mode feedback and correction between a first stage of the differential amplifier and a second stage of the differential amplifier. The differential amplifier is used as a switched capacitor integrator in a switched capacitor filter in combination with an encoder and decoder which is fully differential throughout the circuit.
In particular, the invention is a circuit comprised of a differential signal path in an amplifier having a balanced differential output, a balanced common mode feedback and a common mode signal path. The amplifier in question is the active element in the switched capacitor integrator. The amplifier includes a cascade of two differential amplifiers, each with active loads and a common mode feedback path between the second of the two cascaded differential amplifiers and the first of the two cascaded differential amplifiers.
The integrated circuit includes a transmit side and receive side. The transmit side in turn comprises a third order elliptic antialiasing filter which includes a passive filter section. A fifth order elliptic transmit core filter is coupled to the antialiasing filter and a high pass filter is coupled to the transmit core filter. Each of the filter sections have their sampling frequencies in decreasing magnitude from input to output. For example, the antialiasing filter is over-sampled at a first rate, equal to 1.025 Mhz. The transmit core filter is sampled at a second rate, 128 Khz. The high pass filter is then sampled at a third rate, 8 Khz. The first rate is such that the passive RC section provides enough filtering to avoid aliasing into the passband. The cutoff frequency of the combined antialias filter (passive section and biquad) is such that no aliasing distortion will appear in the transmit side clocked at 128 kHz and the transmit side provides band limiting for the highpass which is clocked at 8 kHz. The receive side of the filter comprises a digital to analog decoder, a decoder output buffer coupled to the digital to analog decoder, and a fifth order caller receive core filter coupled to the buffer. A power amplifier is coupled to the receive core filter. The post filter/power amplifier has a gain setting capability which is independent of frequency and has the sin x/x correction.
These and other advantages and aspects of the invention can be better understood by viewing the following figures in connection with the detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic diagram of the switched capacitor, differential integrator of the invention upon which the circuitry of the filter is based.
FIG. 2 is a block diagram showing the common mode amplifier model of the switched capacitor integrator.
FIG. 3 is a detailed schematic of the amplifier for the switched capacitor integrator.
FIG. 4 is a block diagram showing the overall architecture of the transmit side of the filter encoder combination.
FIG. 5 is a block diagram showing the overall architecture of the receive side of the filter decoder.
FIG. 6 is a detailed schematic showing the circuitry of the anti-aliasing filter.
FIG. 7 is a detailed schematic showing the circuit structure of the transmit core filter section.
FIG. 8 is a schematic showing the circuit structure of the 60 Hz highpass filter section.
FIG. 9 is a schematic showing the auto-zero network.
FIG. 10a is a schematic showing the power amplifier, sin X and X correction, and gain setting capability.
FIG. 10b is a more detailed schematic of the operational amplifier shown in FIG. 10a.
FIG. 11 is a schematic showing the structure of the low noise amplifier.
FIG. 12 is a block schematic showing the structure of the encoder.
FIG. 13 is a plan view of the chip surface illustrating the stached-in-unit concept to lay out the devices in the chip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Better signal to noise ratio and power supply rejection can be achieved in an integrated PCM codec/filter chip with acceptable power dissipation and an acceptable amount of chip area by utilizing throughout the analog-to-digital encoder and digital-to-analog decoder filter a consistent differential treatment of the analog signal. The basic element of the filter circuit and method is a balanced output differential integrator. Power supply variations and coherent noise which are additive to the input and output of any stage within the circuitry are not actually avoided but are cancelled by subtraction of the differential outputs at each stage. The manner in which this arises from the design of the differential integrator can be better understood by considering the operation of the differential integrator as illustrated in FIG. 1. The manner in which this basic building block can be modified and applied in a filter architecture is then described in greater detail beginning with FIGS. 3 and following.
The operation of the differential integrator is based upon a balanced output amplifier and is similar to the circuit as illustrated in FIG. 1. The differential integrator in FIG. 1 is illustrated as having a switched capacitor input 22 with input terminals VI+ and VI-. Differential switched capacitor integrators are well-known to the art, an example of which is discussed by K. Hsieh and Paul Gray, "A Low Noise Chopper Stabilized Differential Switched Capacitor Filtering Technique", Joint Services Electronics Program Contract F49620-79-C-0178 and National Science Foundation Grant NG79-07055. The difference between the input voltages VI+ and VI- is the total input voltage, VI, while the average of each of these inputs is zero. A balanced switched capacitor sampler 22 is shown diagramatically in FIG. 1 as being comprised of two capacitors having an equal capacitance and switched at the input side by a switch 24 and at the output side by a switch 26. The output of switch 26 is coupled to the input of an amplifier 28 which has balanced feedback loops 30 which include a pair of capacitors 32 of equal capacitance. The capacitance of capacitor 32 is ratioed to the capacitance of switched sampler 22. The output of operational amplifier 28 is comprised of a positive voltage output 34, VO+, and a negative voltage output 36, VO-. Outputs 34 and 36 are similarly coupled to a switched capacitor sampler 38 which serves as a common mode feedback, again showed diagramatically as two equal capacitances switched between the outputs 34 and 36, a center input 40, and grounded terminals 42 and a center signal terminal 44. The result of sampler 38 is to keep the average value of the two outputs 34 and 36 equal to zero without affecting the output voltage which is VO equal to VO+-VO-.
It is easiest to analyze the operation of the circuit of FIG. 1 as being comprised of two circuits, namely a differential signal filter circuit and a common mode filter circuit. Common mode signal is that voltage which would be on both terminals as opposed to the differential signal which only appears on the difference of the input and output terminals. Typically, clock noise and power supply variatons are common mode signals. It can be shown that the differential signal transfer function is: ##EQU1## where K is a constant, and Z is a complex variable.
The differential switched capacitor integrator shown has the advantage of being insensitive to parasitic effects. The simplicity of the structure of FIG. 1 is particularly attractive for realizing filters of higher order, especially when direct simulation of a passive ladder is sought. The exploitation of these advantages is better shown in FIG. 6 in regard to the anti-alias filter and in FIG. 8 with regard to the 60 Hz highpass section.
When considering the common mode filter circuit, the circuit of FIG. 1 can be diagrammatically represented as shown in FIG. 2. In other words, the circuit appears as if it were a circuit having a switched capacitor sampler 46 of value C u into which the common mode voltage signal, Vs, 48 is coupled. One of the switched inputs is then coupled to the negative input of an operational amplifier 50 while the positive input is considered as ground or the common potential. The output of operational amplifier 50 is fed back through an integrating capacitor of value, C c . A load capacitance, C L , exists across the input of operational amplifier 50. It can be shown that the transfer function for the common mode configuration is: ##EQU2## where A c is the common mode gain.
Therefore, it can be seen that the common mode circuit has an infinite attenuation at d.c. frequencies and behaves as a highpass filter with the 3 dB point at approximately C U F s /C c , where F s is the sampling frequency at which the switched capacitors are driven. Therefore, it can be readily appreciated that even at rather modest sampling frequencies, the common mode attenuation is small. However, this does not pose any problem as the output of the integrator is always sampled differentially throughout the filter circuit. In the ideal case, power supply rejection is theoretically infinite and only departs therefrom according to the nonidealities of the integrator.
In addition to having theoretically infinite, common mode rejection, the balanced differential integrator has a significant noise advantage as compared to a single ended integrator. Assume that the switched capacitor size and the differential output integrator and the integrating capacitor were halved so that the differential integrator consumes as much capacitor area as a single ended integrator. To a first order of approximation, the switched capacitors contribute thermal noise which is equal to the equivalent of its resistor noise. Therefore, doubling the noise sources would double the noise power. However, at the same time the differential output has twice the voltage swing so that the signal power is quadrupled. Therefore, an additional 3 db of dynamic range is attained by using the differential integrator with an equal amount of capacitance. Furthermore, the integrator does not require any differential to single ended converters or level shifters thereby reducing overall power required in the filter circuit.
By paying careful consideration to the layout plan, as described below, the greater chip area required for a differential amplifier by duplication of the capacitors and associated bussing connections was minimized. In the layout, each core section was treated as a block so that the core amplifiers, integrating capacitors, switched capacitors and their interconnections could be optimized to consume the minimum possible area.
The circuit configuration for the operational amplifier is shown in detail in FIG. 3. The basic amplifier is used in each of the filter sections which will be described below and is modified according to the application in each section. Basically, the amplifier is composed of a cascade of two differential amplifiers which are source coupled pairs cascaded to give a nominal gain of 2000 for the differential signal. The amplifier has an internal feedback scheme for common mode correction of the first stage.
The first stage of the operational amplifier is comprised of differential amplifiers 56 and 58 with their corresponding active loads, 60 and 62 respectively. The second stage is comprised of differential amplifiers 64 and 66 in combination with active loads 68 and 70 respectively. The differential inputs are the gates of devices 56 and 58. Capacitive coupling from the outputs of the second stage of the amplifier to the gate of device 72 form part of the common mode feedback correction loop for the output voltage. Devices 64 and 66 are also coupled as source followers to device 74 which acts as a common source amplifier. Device pair 56 and 58 act as a cascade isolator together with their active load devices 60 and 62. The input common mode feedback loop is completed through the outputs of the first stage to devices 64 and 66. Device 72 forms a common mode amplifier in a common source configuration which is cascaded by device pairs 64 and 66 with active loads 68 and 70. Internal compensation is achieved through capacitances 76 and 78 which are coupled to active loads 70 and 68 respectively in series with resistive elements 80 and 82 respectively. The output of the amplifier is taken from devices 64 and 66 in the second stage.
It can now be understood how the basic amplifier described in FIGS. 1-3 can be employed in a filter circuit to achieve the objects recited above. Consider, for example, the architecture of the transmit side of the filter-encoder combination as shown in FIG. 4, and the receive side of the filter decoder combination as shown in FIG. 5. FIG. 4 illustrates the overall architecture which is functionally similar to the Intel combination 2912/2911 chip set, trademarked integrated circuits sold by Intel Corp., of Santa Clara, Calif., but is markedly different in implementation. The transmit side is comprised of three sections: an anti-aliasing filter section 84, a transmit core section 86, and a highpass filter section 88, a differential encoder 89, and auto-zero circuit 90.
Anti-aliasing filter section 84 is comprised of two stages: (1) a first passive section 91; and (2) a single ended-to-differential converter and an oversampled prefilter 92. The input signal must be band limited before sampled. Passive section 91 acts as a first order filter with an attenuation of 32 dB or greater above 1 MHz. The single ended output of passive section 91 is converted to a differential signal by means of a switched capacitor scheme and coupled to differential, oversampled filter 92. Amplifier 94 is a low noise, high gain operational amplifier which can be set by the user in any feedback configuration. Prefilter 92 will be discussed in greater detail in connection with FIG. 6, and amplifier 94 in FIG. 10.
Tansmit core section 86 is a fifth order elliptic lowpass filter. Filter section 86 uses a two-phase losslers digital integrator (LDI) clocked with a sampling frequency of 128 kHz. The details of transmit core section filter 86 are described in connection with FIG. 7 where it can be seen that the transmission zeroes were realized simply by considering the proper phase inversion acquired at any stage. In addition, the terminations are complex conjugates of each other in a sampling sense to give lower sensitivities.
The cutoff point for transmit core section filter 86 is approximately 3.4 kHz. The sampling frequency in the 60 Hz highpass section 88 coupled to transmit section 86 is 8 kHz. No additional aliasing components are introduced by this sampling frequency. 60 Hz highpass section 88 is a switched capacitor representation of a third order highpass filter and is shown and described in greater detail in connection with the circuitry of FIG. 8. Functionally, highpass section 88 is a simulation of a resistively terminated L C filter. This provides 27 dB of attenuation at 60 Hz and 32 dB at 50 Hz. Inasmuch as highpass section 88 is capacitively coupled to transmit section 86 no voltage offset is propagated through highpass section 88. Feedthrough problems which arise by virtue of the different sampling rates between sections 86 and 88 are handled by the inclusion of additional gates at the interface between the two sections as included within highpass section 88.
Highpass section 88 also includes an auto-zero correction circuit 90 shown in greater detail in FIG. 9. Correction circuit 90 cancels any on-chip DC offset existing in the filter or encoder. The input to circuit 90 is the true sign bit information based upon the comparator output. As described in greater detail in connection with FIG. 9, auto-zero correction circuit 90 operates by successive attenuation of the signal and realization of large time constants. The output of highpass filter section 88 is coupled to a differential encoder of the type as described by Tsividis et al., "UCB Thesis 1975", except that it is fully differential according to the present invention as described in greater detail in FIG. 11.
In FIG. 5, the receive side delivers a differential signal by using the same design concepts as in the various filter sections in the transmit side. The central portion of the receive side is a receive core section 96 sampled at 128 kHz. Circuit configuration of receive core section 96 is identical to transmit core section 86. Correction of end droop of the decoder is processed by a post filter power amplifier circuit 98 coupled to receive core section 96. Details of correction circuit 98 are shown and described in relation to FIG. 10. The common mode requirements of the output of amplifier 98 are stringent since the outputs are to be used in a single-ended configuration. Consider now the detailed circuit implementation for each of these filter sections in light of the above performance requirements.
FIG. 6 shows the circuit implementation of the anti-aliasing filter 84.
Anti-aliasing filter 84 is particularly characterized by a real pole which rises from passive section 91 and two complex conjugal poles which rise from two switched capacitor integrators as better shown in FIG. 6. Together, passive section 91 and prefilter 92 serve as an anti-aliasing circuit for transmit core section 86. Prefilter 92 is oversampled at the rate of 1.024 mHz. Aliasing refers generally to a phenomena observed in all sampled circuitry by which low frequency signals due to the non-audible sampling frequencies are generated into the audible range. As shown in FIG. 6, passive section 91 is comprised of a passive resistor 146 shunted to ground by capacitor 148. The output of passive section 91 is coupled to the switched capacitor input 150 associated with first switched capacitor integrator 152. Switched capacitor integrator 152 is associated with a plurality of differential signal and common mode signal switched capacitor feedbacks and a switched capacitor common mode feedback which are shown in FIG. 6 but shall not be described in detail here since they are implemented in a manner well-known to the art according to the differential teaching of the invention. The output of switched capacitor integrator 152 is coupled to the switched capacitor input 154 of a second switched capacitor 156. Again, switched capacitor 156 is associated with a plurality of switched capacitor differential signal and common mode signal feedbacks which are shown in FIG. 6 but will not be described here in detail.
The unique feature of anti-aliasing filter 84 as shown in FIG. 6 is the cascaded anti-aliasing elements which operate in the differential mode to anti-alias transmit core section 86 which in turn is sampled at 124 kHz. Since the aliasing phenomena is a given fact which can not be avoided wherever sampled circuits are used, section 84 deals with the aliasing problem by attenuating all those higher frequency signals which would otherwise serve as a source for an aliasing signal in the audio range.
Thus, passive section 91 is chosen so that it serves as a lowpass filter to attenuate all signals near 1.024 mHz and above. The prefilter as a whole has a passband edge at approximately 32 kHz to avoid aliasing frequencies at or near 128 kHz at which transmit core section 86 is sampled. The passband edge of transmit core section 86 is approximately 3.4 kHz thereby avoiding any aliasing effect from the 8 kHz sample great in highpass section 88. Because the sampling rate of prefilter 92 is taken at such a high frequency, passive section 91 can easily serve to attenuate any aliasing introduced by the prefilter sampling rate. Similarly, the band edges of anti-aliasing section 86 as a whole and transmit core section 86 by cascading avoid any introduction of subsequent, lower sampling frequencies employed in the following stages.
FIG. 7 shows the transmit core section 86 in greater detail. It can be readily seen that transmit core section 86 is comprised of five switched capacitor integrators, 158-166. The filter of FIG. 7 is a fifth order elliptic lowpass filter which uses two phase LDI clocking which was chosen to reduce the count of switched capacitors as compared to the number which would be required if a bi-linear transform integrator was employed. The relevancy of FIG. 7 is to illustrate the differential signal path which is carried through both the transmit side and receive side of the filter encoder/decoder combination. Unlike single ended filter circuits, signals of both plurality, V+ and V-, are readily available in the differential output amplifiers. Taking advantage of this property, it has been possible to reduce the count of switched capacitors on each side. The transmission zeroes were realized simply by considering the proper phase inversion required at any stage. Again, the switched capacitor network will not be described in detail beyond that given inasmuch as its implementation is specifically shown in FIG. 7 and would be easy to implement with the above teachings. As stated before, the passband of transmit core section 86 has a band edge at approximately 3.4 kHz with -33 dB attenuation at 4.6 kHz and higher.
60 Hz highpass filter section 88 is coupled to the output of transmit core section 86 and is particularly illustrated in FIG. 8. Again, each of the switched capacitor integrators 168-172 has a construction very similar to that shown and described in connection with FIG. 1. The switched capacitors of this section are sampled at 8 kHz since the preceeding section, transmit core section 86, cuts off at 3.4 kHz. Again, the relevant point of the circuitry of FIG. 8 is the illustration of the switched capacitor integrator differential circuit scheme. The input and output feedback switched capacitors, although shown, again will not be described in detail. Once given the purpose of the highpass filter section as taught herein in the circuit structure shown in FIG. 6, it would be clear to one with ordinary skill what values to choose for the capacitors to achieve that result.
FIG. 9 shows the detailed circuitry of auto-zero network 90. Network 90 takes two reference voltages, RF 1 and RF 2 and clocks those voltages through a capacitive voltage divider 174 to the input of a switched capacitor integrator 176. The output of integrator 176 in turn is coupled to a similar capacitive voltage divider 178. The output of capacitive divider 178 is then coupled to the last stage of 60 Hz filter 88. Auto-zero network 90 serves as an integrator with a very long time constant, typically in the order of several seconds. A sign bit is used internally in encoder 89 and represents the true value of the assigned bit. Typically, the sign of the digital number generated by encoder 89 will change rapidly. For this reason, the most significant bit of the eight bit byte use a pseudosign bit which is inserted into the most significant bit as the mode for a unit time of the true sign bit. Input to capacitive voltage divider 174 is based upon the comparator output in the encoder 89 so that a differential reference voltage with the proper polarity is fed into auto-zero network 90. Capacitive voltage divider 174 is an attenuator with an attenuation factor of 40. The attenuation signal is integrated by switched capacitor integrator 176 with a time constant of approximately 31.25 ms. Next, the attenuated signal is again attentuated by a factor of 10 by virtue of capacitative voltage divider 178 and integrated by the following switched capacitor integrator to which it is coupled in highpass filter 88 with a time constant of approximately 1.78 ms. In the normal mode, the step size at the output of transmit core filter section 86 due to auto-zero circuit 90 is 3.5 mv for every 3.125 ms. This works out to be less than one quarter of the least significant bit of offset error during operating circuit.
During power up, it is desirable to make a coarse adjustment in the DC offset on chip. This is done in auto-zero network 90 during the first 40 clock cycles after the circuit is powered up by a signal denoted PCLX which is applied in each of capacitive voltage dividers 174 and 178. The effect of application of signal code PCLX, at devices 180 allows for smaller time constants to be used in the feedback path. Thus, the DC offset is corrected to within a few millivolts while PCLX is high. After that time, normal cycles of auto-zero network 90 takeover and PCLX goes low.
Anti-aliasing filter 84, in addition to passive section 91 and prefilter 92, includes a low noise amplifier 94. Amplifier 94 finds its primary application as an uncommitted operational amplifier that can be used for gain setting, line balancing and so forth. As a consequence, the inputs and outputs have to be available to the user. A differential structure would not be attractive because of the extra associated circuitry. From the user's standpoint, the specifications should be approximately the same as those found in any general purpose operational amplifier with respect to voltage gain, bandwidth noise, offset and the like. This is difficult to achieve in inloss circuitry which is particularly characterized by low voltage gains. The typical, prior art operational amplifier configuration was comprised of a cacase of a differential amplifier of transconductance GM 1 followed by an integrative stage of a DC gain of 82 and a unity gain buffer. The DC gain is given by:
A.sub.DC =G.sub.m1 R.sub.L A.sub.2
where R L =load, G m1 =transconductance. The general previously used solution was to precede the transconductance stage with a preamplifier gain A 1 , thereby modifying DC gain to:
A'.sub.DC =(A.sub.1 G.sub.m1)R.sub.L A.sub.2
The equation above can be associated mathematically to read:
A'.sub.DC =G.sub.m1 (A.sub.1 R.sub.L)A.sub.2
FIG. 11 shows the circuit for the low noise amplifier which implements the above equation. The differential inputs 134 coupled to the gates of transconductance devices 136. The outputs of devices 136 are coupled to the differential input of operational amplifier 138 which has gain A 1 . The output of amplifier 138 is coupled to the gates of depletion devices 140. Output is then taken to a voltage amplifier 142 of gain A 2 . Thus, high gain can be achieved without increasing the value of capacitor 144 which would otherwise be necessary to preserve the band with instability but for the inclusion of operational amplifier 138 at the outputs of transconductance 136. Therefore, instead of preceeding transconductance devices 136 by a preamplifier of gain A 1 , the last equation above can be implemented to achieve a high gain, low noise circuit in NMOS technology without sacrifice of stability of band width.
FIG. 10 illustrates the detail of circuit implementation for power amplification correction circuit 98. The operation of the power amplifier is based on an operational amplifier 100 described in greater detail in FIG. 10B. Amplifier 100 is associated with a number of switched capacitor groups. The first group is switched capacitors 102 which are used to form part of the gain setting circuit of the power amplifier shown as a whole in FIG. 10a. Gain setting switched capacitors 102 are shown on both sides of the balanced output of amplifier 100. Capacitor group 104 forms part of the frequency setting circuit while switched capacitor group 106 are the input switched capacitors to amplifier 100. The outputs 108 from amplifier 100 are coupled together by a two resistor network comprised of resistor 110 and 112.
Analysis of the circuit in FIG. 10a would show that power amplification circuit 98 is particularly characterized by having buffer outputs capable of driving a 600 ohm, 100 pF load differentially or a 300 ohm, 200 pF load single ended. With a minimum of off chip pairs, namely three, two discrete resistors can be externally used to continuously vary the gain in a matter which does not affect the frequency response of the circuit. In addition, the frequency response of the circuit is particularly tailored to correct the sin X over X distortion which is inserted by all sampled encoders and decoders.
Resistors 110 and 112 are connected in a differential voltage divider configuration. The voltage developed across resistor 112 is rated by capacitors CnM and C 2 M in the upper group of switched capacitors 102. This weighted voltage is then added to the portion defined by the frequency setting group 104, Cu and C 2 to set the total amount of feedback. It can be seen be inspection that the maximum gain condition will by for resistor 110 to be non-zero with resistor 112 zero. Similarly, the minimum is for resistor 110 to be zero and resistor 112 to be non-zero. In order for the frequency response of power amplifier 98 to be independent of the ratio of resistors 110 and 112, the capacitances Cu, C 2 , Cum, and C 2 m are chosen to satisfy the following ratio:
C.sub.4 /C.sub.um =C.sub.2 /C.sub.2m
Common mode feedback is also implemented dynamically through switched capacitor 114. The positive input of the common mode operation of amplifier 100 is referred to a bias point which is decoupled from the power supply by a passive switched capacitor filter which limits the amount of noise transferred from this power supply to the outputs.
Special requirements are imposed upon operational amplifier 100 which are not required of the amplifier illustrated in connection with FIG. 1. For example, the outputs of amplifier 100 must be buffered to drive 300 ohms each in the performance of the common mode operation, the amplifier has to be comparable to the differential mode of operation for those users interested in extracting a single ended output. Finally, the compliance of the differential input has to be large enough to handle the common mode signal introduced by the gain setting network in the maximum gain configuration. FIG. 10b illustrates in simplified form the schematic of power amplifier 100. The circuit of FIG. 10b is uniquely characterized by two similar signal paths, a differential signal path and a common mode signal path. The voltage gain and band width performance of the amplifier is essentially the same with respect to both signal paths. The differential input 116 is coupled in parallel to the gates of devices 118 and 120. The differential output from devices 118 is coupled through a compensating network to output buffers 122 which are class AB push pull amplifiers chosen for minimum quiescent power. The differential output of devices 120 is coupled through current mirrors 124 and coupled through lines 126 to the appropriate nodes 128 and the differential output path.
The common mode input is coupled to the gates of devices 130. As illustrated in FIG. 10b, devices 130 are coupled in series between the first differential stage comprised of devices 118 and the second differential stage 120. Differential stages 118 and 120 are in each case balanced and parallel. A differential signal applied to common mode inputs 132 cause the output from the amplifier VO+ and V0- to move in the same direction whereas a differential input to the inputs 116 will cause the differential outputs to move in the opposite directions or in a differential manner. Common mode inputs 132 are also shown in FIG. 10 as the input points to amplifier 100 from the common mode biasing circuitry 113.
FIG. 12 shows the differential signal path continued through encoder 89. The differential output from highpass filter 88 is coupled to input 182. One input is coupled to a binary weighted positive capacitor array 184 while the other input is coupled to a binary weighted negative capacitor array 186. The output of each capacitor array is coupled to the differential inputs of comparator 188. Comparator 188 in turn is coupled to decision logic 190 which is comprised of random logic elements used to switch in either positive or negative capacitors in arrays 184 and 186. Thus, the analog signals present in inputs 182 represented through arrays 184 and 186 to comparator 188. A positive or negative comparator signal will be generated and processed by decision logic 190. The digital number is generated from the analog output by halving. In other words, decision logic 190 first looks to see whether the analog signal is above zero or below zero. If it is above zero, it then switches in the appropriate capacitors in array 184, which are merely a parallel array of switched capacitors, to determine whether the analog signal is above one quarter or below one quarter. Again, a differential signal will be generated at the output of comparator 188 depending on whether the signal is above or below one half. If the signal is above one half, decision logic circuitry 190 continues the cycling by determining whether or not the signal is above or below three quarters and so forth. Untimately, a 8 bit word is generated which is the digital representation of the analog input signal. When cycling is completed, decision logic 190 transfers the digital word to the chip output 192. The unique feature of the encoder as illustrated in FIG. 12 is that the differential scheme is continued through each of the filter sections and into encoder 89 in the manner just described.
Without a detailed consideration, the use of chip area to implement the circuits shown in FIGS. 1-10 would be excessive and unacceptable. Chip area minimization has been achieved in the invention by a stack and unit device concept. The objective of the concept is to limit the amount of metal lines running over field regions. Since, in principle, metal is electrically isolated from the rest of the layers unless contact windows arbitrarily open, it is usually adantageous to run metal lines over diffusion of poly regions. Metal lines are layed out in a north-to-south direction with diffusion of poly regions layed out in a east and west direction. A constant width is chosen for the widest transistor and this defines a unit transistor. Therefore, transistors are packed onto the chip by stacking. In a local oxidation process it is well-known that capacitance at the boundary between diffusion and field region is large due to the field implant. Therefore, isolated diffusion regions should be avoided if possible. FIG. 11 illustrates the stack and unit device concept.
It is clear at this point that the number of capacitors used in both the transmit and receive sides of the present invention is large. The demands made on chip area are correspondingly large. FIG. 13 shows the stacked unit concept by which a maximum number of capacitive elements may be formed in a chip substrate.
Firstly, the entire circuit design is based upon the assumption of a unit length for each transistor. If a larger transistor is required in the unit transistor, then it is achieved by stacking links so that a multiple of unit links are combined. FIG. 13 shows a device having a unit link 182 for diffusion region 184. Polycrystalline silicon region 186 is shown as stacked by being connected by arm 188 and by traversing fusion region 184 twice. If a third link is required, polycrystalline silicon region 188 would again be serpentined across fusion region 184 to obtain a third multiple. Rather than choosing arbitrary circuitry parameters then, each of the circuit parameters of the devices shown in the preceeding figures are chosen based on the unit transistor width selected in FIG. 13. Polycrystalline regions run east and west and metal lines 188 run north and south. By using these design rules, the number of devices can be easily placed within a supplemental amount of chip area. For example, the core amplifier as shown in FIG. 1 can be fabricated in approximately 7.07×10 -4 mm 2 ; the power amplifier illustrated in FIG. 10a can be fabricated in 53.4×10 -4 mm 2 ; and the low noise amplifier as illustrated in FIG. 11 can be fabricated in 26.88×10 -4 mm 2 .
Although the present invention has been described in connection with a specific filter and filter architecture, it must be understood that the invention can be modified by those having an ordinary skill in the art without departing from the spirit and scope. For example, although the illustrated embodiment is in terms of a voice band filter for use in analog-to-digital encoding and decoding, it must be understood that the differential technique taught here can be employed in any integrated circuit filter where the power supply rejection is required, good noise to dynamic range ratios are required, power dissipation must be minimized, and chip area minimized.
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An integrated circuit employing a differential integrator and switched capacitor network to provide auto-zeroing. The differential integrator utilizes a feedback circuit between its inputs and outputs. A switched capacitor network coupled to the inputs of the amplifier provides voltage division of differential reference signals which determine the amount of DC offset. The amplifier then integrates the reference signals to a predetermined time constant, wherein the average voltage of the output of the integrator is used to provide auto-correction of the DC offset. A second switched capacitor voltage divider network and a second differential integrator cascaded to the first circuit provides a second time constant for fine-tuning the auto-correction signal.
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FIELD OF THE INVENTION
This invention relates in an olefin polymerization process and particularly a process for polymerization of olefins in liquid medium. The invention further relates in polymerization processes containing a prepolymerization step. This invention also relates in an olefin polymerization apparatus.
BACKGROUND OF THE INVENTION
Various methods for manufacturing solid polymers from hydrocarbons, for example from 1-olefins have been developed. In one such method olefins, such as ethylene, propylene or butene, are polymerized in the presence of catalysts in hydrocarbon diluents or in monomers acting as diluents. The reactants are kept in liquid phase by maintaining a proper pressure in the polymerization reactor. When the polymer is insoluble or only slightly soluble in the diluent, the polymer product forms as particles suspended in the diluent and therefore the process is called a slurry process.
As batch process the above process has the advantage that all the polymer particles have the same residence time in the reactor and therefor the product quality is even. However, in commercial high production plants the polymerization reactors tend to be large. The operation is labor extensive and the quality of the products from batch to batch is not the same. For these reasons the batch reactors are not commercially acceptable.
A typical continuous slurry process is carried out in a continuous pipe reactor forming a loop, where the polymerization is carried out in a circulating turbulent flow. The product containing polymer, diluent and monomers, is taken from the loop reactor either continuously, or more usually, periodically through a discharge valve and it is introduced to a separator, where the polymer is separated by lowering the pressure.
Another reactor type in olefin polymerization art is a gas phase reactor, where polymerization is carried out in the presence of catalysts and gaseous monomers. Typically the polymerization is carried out in fluidized bed reactors, where polymerization is carried out continuouly in a bed formed by polymerizing polymer particles. This bed is kept in fluidized state by circulating gaseous flow from the top of the reactor to the bottom of the reactor. Polymerization heat is removed by cooling said circulating gaseous flow.
It is also known continuous multiphase processes, where slurry reactors, such as loop reactors are followed by one or more gas phase reactors or where two or more gas phase reactors are used in series.
A known problem in continuous processes is that even residence time of catalyst is difficult to achieve. Therefore the product quality tends to be more or less uneven. This phenomena is exaggerated in multiphase processes. The catalyst is usually fed into the first reactor only. Some of the catalyst particles react with the monomers for a longer period, whereas part of the catalysts flows straight through the reactor and will be removed more or less unreacted. In the next reactor the unreacted catalyst particles react differently with monomers and resulting, among others, in uneven product quality, gels, lumps and more difficult process control.
It is also known to prepolymerize a small amount of olefin monomer with a catalyst before using these catalysts into a main polymerization reactor. Typically such prepolymerization reduces catalyst attrition and improves the resulting polymer morphology. Prepolymerized catalysts also may suspend more readily in hydrocarbon solvents, yield polymers of higher bulk density and reduce formation of lumps in gas phase reactor.
Such prepolymerization can be carried out by contacting a solid catalyst component with a small amount of olefin monomer in a suitable diluent or monomer in a vessel separate from the main polymerization reactor.
The most convenient way to prepolymerize is a continuous prepolymerization, but due to residence time distribution, part of the catalyst will not prepolymerize enough and will produce fines in the main polymerization reactor. A batch prepolymerization often reduces the catalyst activity and there is always some difference between prepolymerized catalyst batches. Some catalysts have to be prepolymerized so much that the amount of polymer may cause the catalyst handling to be too troublesome.
Some catalyst feeders feed small batches of catalyst with a cycle time of several seconds or minutes. This sometimes causes fluctuation in prepolymerization or in actual polymerization.
The common problem in all polymerization processes mentioned above is uneven residence time distribution, which leads to uneven and undesirable product quality and more difficult process control. This problem can be to some extent avoided if tubular, very long reactors having a very small diameter is used. For example in EP 0279153 a prepolymerization method is disclosed, where the prepolymerization is carried out as a plug flow. However, that kind of reactors are difficult to control and they are not suitable for high production rates because of risk of plugging and low capacity.
Therefore need exists for olefin polymerization processes where the polymerization can be carried out so that more narrow residence time distribution can be achieved and the problems arising from the uneven polymerization degree can be avoided.
OBJECTS AND SUMMARY OF THE INVENTION
The object of the present invention is to achieve a polymerization process, where the disadvantages described above can be avoided. Another object of the present invention is to achieve a process for olefin polymerization, which can be applied as well in normal polymerization as catalyst prepolymerization. Still another object of the invention is to achieve polymerization processes where the catalyst used is prepolymerized in certain way.
Thus the invention concerns a process for polymerization of olefin monomer in fluid medium in the presence of olefin polymerizing catalyst, diluent and optional co-catalyst and donors, said process comprising the steps:
forming a fluid stream containing said catalyst,
continuously feeding said fluid stream into an elongated polymerization reactor comprising at least two successive chambers separated by dividing plates having a diameter slightly smaller than that of the polymerization reactor,
feeding into said polymerization reactor monomer and optionally cocatalyst and donor under temperature conditions to polymerize said olefin while maintaining a mixed flow in said chambers to polymerize the monomer and optional comonomer in the fluid, and
removing the resulting polymer slurry from said polymerization reactor.
The invention also concerns an apparatus for polymerization of olefin monomer and optionally other monomer in the presence of olefin polymerizing catalyst, diluent and optional cocatalyst and donors, said apparatus comprising:
means for continuously feeding a fluid stream containing said catalyst into an elongated polymerization reactor comprising at least two successive chambers separated by dividing plates having a diameter slightly smaller than that of the polymerization reactor,
means for feeding into said polymerization reactor monomer and optionally cocatalyst and donor under temperature conditions to polymerize said olefin while maintaining a mixed flow in said chambers to polymerize the monomer and optional comonomer in the fluid, and
means for removing the resulting polymer slurry from said polymerization reactor.
The invention also concerns an apparatus for prepolymerizing olefin polymerization catalyst.
According to the invention the polymerization takes place in an elongated reactor, preferably in cylinder-like reactor, which has an inside diameter greater than that of the inlet and outlet points. The term “elongated” means that the length/diameter ratio of the reactor is greater than 2, preferably more than 2,5
According to the invention the polymerization reactor comprises at least two successive chambers separated by dividing plates having a diameter slightly smaller than that of the polymerization reactor. Preferably the polymerization reactor is divided to several successive chambers.
In such polymerization reactor preferably each part of the chambers can be equipped with some mixing device in order to eliminate the deposition of the catalyst or forming polymer onto the surfaces of the polymerization reactor. As mixer device one or more rotating or static mixers can be used. The static mixers may also be attached to the walls of the reactor.
The chambers are divided from each other with plate-like members so that a narrow gap is situated between the chambers. Therefore the diameter of the plates is preferably slightly smaller than the inside diameter of the polymerization reactor. However, it is also possible that the diameter of the dividing plates is smaller. Generally it can be said that the diameter can be 1-25 mm less than the inner diameter of the reactor. When the polymerization reactor is divided to several chambers, the diameter of the dividing plates can decrease thereby eliminating the risk of plugging. The gap between the diameter of the reactor and the diameter of the dividing plate in the last chamber is preferably smaller than the diameter of the outlet opening of the reactor.
According to one embodiment of the invention the dividing plates and the mixers between the dividing plates are attached to the same shaft.
Liquid and the catalyst particles flow to the next chamber between the separation plate and the wall of the reactor. Rotation of the disk keeps the area clean. In the first chamber of the reactor the catalyst mean residence time is of at least 3 times, preferably 10 times the cycle time of the catalyst feeder to assure that there is minimal fluctuation in the catalyst feed to the actual polymerization in the later chambers.
The reactor can be vertical or horizontal, although the vertical position is preferable. Plug flow behaviour in the reactor according to the invention assures that every active catalyst particle has enough prepolymer to prevent the breakage in later polymerization.
As an additional feature the reactor according to the invention can contain additional flow mixing means located in the inner surface of the reactor. Such means can, for example, be studs attached to the inner surfaces of the reactor in some or each chambers and/or the cover plate of the reactor. Such mixing elements enhance the mixing effect by forcing flow from the reactor walls towards the central parts of the reactor.
The flow mixing means can also comprise supporting bars, which support a bearing block for the central shaft. The bars are preferably locked by friction on the reactor walls or by other means.
A fluid carrier stream containing the polymerization catalyst or part of the polymerization catalyst is formed and fed into this reactor. A second stream of polymerizable monomer or monomers is also fed to the reactor. Other components of the catalyst system can also be fed to this reactor.
As fluid carrier stream inert hydrocarbon diluents can be used. Such diluents include, among others, propane, butane, pentane, hexane and alike. Also polymerizable monomers can be used as the fluid carrier. Such monomers include for example propylene, butene and hexene. The mixtures of the fluid carriers mentioned can also be used.
The polymerization takes place inside of the reactor as a mixed plug flow. This term means that the flow inside of the reactor takes place as mixed flow, the flow direction of which is, however, generally forward from one end of the reactor to other end. No part of the reactor contents flows backwards through the reactor and no stagnant flow regions exist where the flow remains in place longer than other parts of the flow.
The residence time in the reactor depends on such factors as the catalyst used or the polymerization degree desired, but generally the advantages of the invention are achieved when the residence time is more than one minute, preferably from two minutes to 30 minutes. A shorter time is sufficient when the polymerization reactor is used as a prepolymerization reactor and longer periods are necessary when the polymerization reactor is used as the ordinary polymerization reactor.
At least part of the cocatalyst is fed to the first chamber of the reactor according to the invention. The monomer or monomers can be fed to any or every chamber of the reactor. In case of propylene polymerization also the donor can be fed to any of the chambers or along with the catalyst.
The polymerization heat is removed by cooling. The cooling can be carried out with a cooling jacket surrounding the polymerization reactor. However, other methods for cooling can also be used.
The reaction temperature can be selected within a wide range, for example in the range of 0° C. to 90° C. The pressure can be likewise selected within a wide range, for example between 10 bar-100 bar. The cooling jacket can be divided into several compartments to make possible to use temperature gradient over the length of the reactor.
Use of solid, transition metal-base polymerization catalysts for polymerization of olefins is well known. Typically these catalysts are based a complex derived from a halide of a transition metals, such as titanium, vanadium, chromium and zirconium, and a cocatalyst, which are typically based on metal alkyls, such as organoaluminum compounds. A typical catalyst comprises a titanium halide, which is supported on a magnesium halide complexed with an alkyl aluminum. It is also known to use electron donors or Lewis bases for controlling the stereospecifity of the polymer. Examples of such electron donors are, among the others, ethers, esters and siloxanes. Except of Ziegler-Natta catalysts described above also metallocene type catalysts can be used according to the invention.
The catalyst component to be fed to the reactor can also be mixed in appropriate medium. Such medium can be for example hydrocarbon wax. The catalyst can also be prepolymerized in conventional way and further treatment is carried out according to the invention.
The process of the invention is particularly advantageous in prepolymerization of such catalysts. Every stage of prepolymerization can be carried out in different conditions. Eg. temperature, monomer, diluent, cocatalyst and donor concentrations can be varied. Different monomers can be used in different stages of prepolymerization. Different components can be contacted in certain order to achieve optimum performance of the catalyst. Further conventional antistatic agents can be fed to the reactor in any desired point.
The design of the reactor according to the invention is easy to manufacture. No extra flanges or walls are needed which could plug the reactor. The number of chambers can changed simply by reducing or adding separation plates and mixing elements also afterwards.
The process according to the invention is particularly advantageous applied as prepolymerization step in various polymerization process. Thus one object of the invention is a process for polymerization of olefin monomer in the presence of olefin polymerizing catalyst, diluent and optional cocatalyst and donors, by feeding into at least one polymerization reactor monomer(s), diluent, catalyst, cocatalyst and optional hydrogen and/or donor under temperature conditions to polymerize said olefin(s) to olefin polymers and after polymerization removing said polymers from the reactor. The process is characterized in that the catalyst fed into the polymerization reactor is prepolymerized by forming a fluid carrier stream containing said catalyst, continuously flowing said carrier stream into an elongated prepolymerization chamber containing at least two successive chambers separated by dividing plates having a diameter slightly smaller than that of the prepolymerization chamber, feeding into said prepolymerization chamber monomer and optionally cocatalyst and donor by maintaining a mixed plug flow in said prepolymerization chamber for a period of at least one minute under temperature conditions to prepolymerize said olefin onto said catalyst, and feeding said prepolymerized catalyst into the first polymerization reactor.
Thus the prepolymerization of the catalyst is carried out first and the process further can comprise one or more slurry reactors after said prepolymerization step. The slurry reactors can be conventional stirred-tank reactors or loop reactors.
The process according to the invention can also comprise also a process where the preceding prepolymerization step is followed by one or more gas phase reactors.
Further the polymerization process following the preceding prepolymerization step can also be a combination of slurry and gas phase polymerization steps. The slurry polymerization step is preferably a loop reactor step.
In slurry processes the pressure in the prepolymerization vessel is selected preferably so that it is higher than in the following reactor. Thus the transfer of the prepolymerized catalyst from the prepolymerization chamber into the slurry reactor is as easy as possible, because the catalyst can be straight moved to the next reactor. Thus the pressure can be for instance between 40-90 bar, preferably 50-70 bar, however provided that the pressure is higher than in the next slurry reactor. The transfer of the prepolymerized catalyst can be carried out also periodically, if desired, and also conventional catalyst transfer devices can be used, if necessary.
It is recommendable that the whole catalyst amount in the process will be fed to the prepolymerization according to the invention and no extra catalysts will be fed to the slurry reactor or reactors. Instead it is possible to feed the cocatalyst either only to the prepolymerization step or partly into the prepolymerization chamber and partly to the slurry polymerization reactor or reactors.
Low boiling inert hydrocarbon is fed to the slurry reactor as polymerizing medium. Examples of suitable hydrocarbons are aliphatic hydrocarbons like propane, butane, pentane and hexane. Advantageous hydrocarbons are especially propane and isobutane. It is also possible to use a mixture of one or more hydrocarbons mentioned before. In the case of propylene polymerization the polymerization medium is preferably propylene.
The reaction mixture consisting of a reaction mixture from previous reactor together with added fresh monomer, hydrogen, optional comonomer and cocatalyst is circulated continuously through the slurry reactor, whereby more suspension of polymer in particle form in a hydrocarbon medium or monomer will be produced. The conditions of the slurry reactor will be chosen so that at least 12 w-% of the whole production will be polymerized in each slurry reactor. The temperature can be chosen within the range of 40-110° C., advantageously within the range 50-100° C. The reaction pressure can be chosen within the range of 40-90 bar, preferably within the range or 50-70 bar, however provided that the reaction pressure is lower than the pressure of the previous reactor. The residence time must be at least 10 minutes, but preferably in the range of 0.5-2 hours.
In slurry polymerization more than one reactors can be used in series. In such case the polymer suspension in an inert hydrocarbon or in monomer produced in the slurry reactor is fed without the separation of inert components and monomers periodically or continuously directly to the latter slurry reactor, which acts in lower pressure than the previous slurry reactor.
Further it is possible to operate one or more slurry reactors at temperatures and pressures that are above the critical temperature and pressure of the polymerization medium. The polymerization then takes place under supercritical conditions.
The type of the slurry reactor(s) can be conventional stirred-tank reactors or loop reactors or the combination thereof. Preferably loop reactors are used.
The reactor according to the invention can be used also as a prepolymerization reactor before one or more gas phase reactors. Gas phase reactor can be an ordinary fluidized bed reactor, although other types of gas phase reactors can be used. In a fluidized bed reactor the bed consists of the formed and growing polymer particles as well as still active catalyst come along with the polymer fraction. The bed is kept in a fluidized state by introducing gaseous components, for instance monomer on such flowing rate which will make the particles act as a fluid. The fluidizing gas can contain also inert carrier gases, like nitrogen and also hydrogen as a modifier.
The gas phase reactor used can operate at temperature region between 50-115° C., preferably between 60-110° C. and the reaction pressure between 10-40 bar and the partial pressure of monomer between 2-30 bar.
According to still another embodiment the reactor of the invention is used as a prepolymerization reactor which is followed by a slurry reactor or reactors and a gas phase reactor or reactors.
In every polymerization step it is possible to use also comonomers selected from ethylene, propylene, butene, pentene, hexene and alike as well as their mixtures.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further illustrated by figures, in which
FIG. 1 a illustrates the polymerization device according to the invention, which can be applied as a polymerization reactor or as prepolymerization reactor,
FIG. 1 b is an enlargened cross-sectional view of the reactor of FIG. 1 a along the line A—A, and
FIG. 2 is a schematic flow graph one preferable embodiment of the invention comprising a prepolymerization reactor followed by a loop reactor and a gas phase reactor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a and 1 b the polymerization reactor according to the invention is denoted by a numeral 1 . The polymerization reactor 1 has a generally elongated cylindrical form defined by inner surface 2 , deck plate 3 a and bottom plate 3 b . The length/diameter ratio of the reactor 1 is at least 2 , preferably more than 2.5. The reactor 1 can be cooled by a cooling jacket 4 , which can partly or entirely surround the inner wall 2 of the reactor 1 . The cooling jacket 4 can be divided to several separate cooling chambers by separators 5 . Cooling medium is introduced to the cooling jacket 4 by line 6 and valves 7 and it is removed from the cooling jacket 4 through valves 8 and line 9 . Thus different reaction temperatures can be applied in the reactor when needed.
The reactor is equipped with a central shaft 10 extending over the height of the reactor 1 . The shaft 10 is rotated by suitable means 11 . The inside volume of the reactor 1 is divided into at least two chambers 12 a by dividing plates 12 b attached to the central shaft 10 . The diameter of each dividing plate 12 b is slightly smaller than the inside diameter of the reactor 1 leaving a gap of 2-25 mm between the edge of the dividing plate 12 b and the inside wall of the reactor 2 . The number of the dividing plates 12 b can be varied between 1 to 100 thereby allowing two or more sequential polymerization chambers 12 a inside the reactor 1 .
The reactor 1 is further equipped with mixing elements 13 inside of the chambers 12 a . The mixing elements 13 are attached to the central shaft 10 to rotate along with it. The mixing elements 13 can be also static elements 14 attached into the inside wall 2 of the reactor 1 and extending inside of the chambers 12 a . Such static mixers 14 can be located in different places in the reactor wall 2 and also in the deck and bottom plates 3 a , 3 b of the reactor 1 .
The shaft 10 can also be supported by bearing block 15 . In such arrangement the bearing block 15 is supported to the inside wall 2 of the reactor 1 by bars 16 . The supporting bars 16 give an efficient mixing effect on the circulating flow of the polymerization medium in the reactor 1 . The ends of the supporting bars 16 can be supported on the reactor wall 2 by friction or by other means thereby preventing the rotation.
The catalyst from reservoir 17 is fed to the feeding device 18 where it is mixed with a diluent from line 19 and is further fed to the reactor 1 through line 20 . The same or different monomers can be fed to the reactor 1 through lines 21 a and/or line 21 b and valves 22 . Cocatalyst and donors can be fed into the reactor 1 from reservoir 23 and a feeding device 24 with a diluent from line 25 . In the same wise same or different cocatalysts and monomers can be fed into the reactor 1 from line 26 and valves 27 .
The polymer or prepolymer is removed from the reactor 1 through line 28 . From line 29 it is possible to feed also antistatic agents to the polymer or prepolymer.
In FIG. 2 it is presented a schematic view of one process where the prepolymerization reactor 1 according to the invention is used combined with loop-gas phase sequence.
Catalyst from reservoir 30 is fed to the feeding device 31 together with diluent from line 32 . The feeding device 31 feeds the catalyst/diluent mixture into the prepolymerization chamber 1 via line 33 . Monomer is fed through line 34 and cocatalyst and possible donors can be fed into the reactor 1 through lines 35 .
From the prepolymerization chamber 1 the prepolymerized catalyst is removed preferably directly through line 36 to a loop reactor 40 . In the loop reactor 40 the polymerization is continued by adding a diluent from the line 42 , monomer from line 43 , hydrogen from line 44 and an optional comonomer from line 45 through the line 46 . To the loop reactor 40 it can be added also optional cocatalyst in an ordinary way (not presented).
From the loop reactor 40 the polymer-hydrocarbon mixture is fed through one or several exhaust valve 47 and the product transfer line 48 to the flash separator 50 . The hydrocarbon medium removed from the polymer particles, the remaining monomer and hydrogen are removed from the flash separator 50 either through the line 51 to the recovery unit (not presented) or back to the loop reactor 40 through the line 46 . The polymer particles are removed from the flash separator 50 through the removing line 52 to the gas phase reactor 60 .
In the lower part of the gas phase reactor 60 there is a bed consisted of polymer particles, which will be kept in a fluidized state in an ordinary way by circulating the gases removed from the top of the reactor 60 through line 61 , compressor 62 and the heat exchanger (not presented) to the lower part of the reactor 60 in an ordinary way. The reactor 60 is advantageously, but not necessarily, equipped by a mixer (not presented). To the lower part of the reactor 60 can be led in a well known way monomers from line 63 , optionally comonomer from line 64 and hydrogen from the line 65 . The product will be removed from the reactor 60 continually or periodically through the transfer line 66 to the recovery system (not presented).
EXAMPLES
Highly active catalyst and highly active polymerization conditions (e.g. enough hydrogen) were used to test the properties of the novel system. For the examples 1-6 highly isotactic (98±1%) homopolymer with MFR (2,16 kg 230° C.) 20±1 g/10 min was produced. Normal temperature of 70° C. and higher temperature of 94° C. were tested in the actual polymerization.
Example 1
A pilot plant operated continuously was used to produce PP-homopolymer. The plant comprises a catalyst, alkyl, donor and propylene feed systems and a small stirred tank reactor named as CCSTR due to several compartments. Said components are fed to the CCSTR.
The catalyst used was a highly active and stereospecific ZN-catalyst made according to Finnish Patent No. 88047. The catalyst was contacted with triethylaluminium (TEA) and dicyclopentyldimethoxysilane (DCPDMS) (Al/Ti ratio was 3 and Al/donor was 3 (mole)) before feeding to the CCSTR.
The catalyst was fed according to Finnish Patent No. 90540 and was flushed with propylene (15 kg/h) to the CCSTR in which also TEA and DCPDMS are fed. The CCSTR was operated at 40 bar pressure, 20° C. temperature and mean residence time of the catalyst at 3 min. Al/Ti (mole) ratio was kept at 150 and Al/donor ratio at 5.
The loop reactor was operated at 39 bar pressure, 70° C. temperature and mean residence time of the catalyst at 3 h. The solid polymer was separated from the polymer slurry by depressurising. The MFR (2.16 kg, 230° C.) of the produced PP-homopolymer was controlled to be 20 via hydrogen feed. Product characteristics is shown in Table I.
Example 2 (Comparative)
Procedure was the same as Example 1 but the compartmented CCSTR was replaced with normal continuous stirred-tank reactor (CSTR).
Example 3
Procedure of the Example 1 was repeated.
Example 4
Procedure was the same as Example 1 but the mean residence time of the catalyst was kept at 4 min.
Example 5 (Comparative)
Procedure was the same as Example 4 but the compartmented CCSTR was replaced with normal CSTR.
Example 6
Procedure was the same as Example 1 but the mean residence time of the catalyst was kept at 2 min.
Example 7 (Comparative)
Procedure was the same as Example 6 but no continuous prepolymerization was used. The catalyst was prepolymerized with propylene (the mass ratio of PP/cat was 10) in batch according to Finnish Patent No. 95387.
The catalyst was mixed with TEA and DCPDMS and flushed with cold propylene to the loop reactor.
Example 8 (Comparative)
Procedure was the same as Example 2 (comparative) but the catalyst was pre-polymerized with propylene (the mass ratio of PP/cat was 10) in batch according to Finnish Patent No. 95387 before continuous prepolymerization.
Example 9
A pilot plant operated continuously was used to produce PP-homopolymer. The plant comprises a catalyst, alkyl, donor and propylene feed systems and a stirred tank reactor named as CCSTR due to several compartments. Said components are fed to the CCSTR.
The catalyst according to Example 1 was fed into the CCSTR-reactor, which was operated at 51 bar pressure, 20° C. temperature and mean residence time of the catalyst at 5 min. Al/Ti (mole) ratio was kept at 75 and Al/donor ratio at 5.
The polymer slurry from the CCSTR was fed to a loop reactor in which also hydrogen and more propylene was fed. The loop reactor was operated at 50 bar pressure, 94° C. temperature and mean residence time of the catalyst at 30 min. The solid polymer was separated from the fluid by depressurising. The MFR (2.16 kg, 230° C.) of the produced PP-homopolymer was controlled to be 20 via hydrogen feed. Product characteristics is shown in Table II.
Example 10 (Comparative)
Procedure was the same as Example 9 but no continuous prepolymerization was used. The catalyst was prepolymerized with propylene (the mass ratio of PP/cat was 10) in batch according to Finnish Patent No. 95387.
The catalyst was mixed with TEA and DCPDMS and flushed with cold propylene to the slurry reactor.
Example 11 (Comparative)
As Example 7 (comparative) except that the catalyst was prepolymerized to mass ratio of 7 (PP/cat) in batch according to Finnish Patent No. 95387, cyclohexyl-methylmethoxysilane (CHMMS) was used as donor, Al/Ti (mole) ratio was kept at 100 in the loop reactor, and MFR (2.16 kg, 230° C.) of the produced PP-homo-polymer was controlled to be 2.5 via hydrogen feed.
Product characteristics are shown in Table III.
Example 12 (Comparative)
As Example 11 (comparative) except that a small diameter pipe with inner diameter of 4 mm was used and the length of the pipe was selected to give 20 second residence time for the catalyst and the pipe was operated at 0° C.
Example 13 (Comparative)
As Example 12 (comparative) but the pipe was operated at 20° C.
Example 14 (Comparative)
As Example 13 (comparative) but the length of the pipe was selected to give to give 40 second residence time for the catalyst. Line was impossible to operate for longer period of time—no product characteristics available.
Example 15
Procedure was the same as Example 1 but the temperature of the upper part of prepolymerization reactor was 20° C. and the temperature of the lowest part of prepolymerization reactor was 40° C. The mean residence time of the catalyst was at 7 min. 50 w-% from total hydrogen feed was fed into the prepolymerizatior reactor and 50 w-% into the loop-reactor.
Product characteristics are shown in Table IV.
Example 16
Procedure was the same as Example 1 but the compartment CCSTR was replaced with two compartments (separated by one dividing plate) on upper part of prepol. reactor and in lowest part with three vertical equalizing grids.
Example 17
Procedure was the same as Example 16 but a metallocene catalyst, rac-dimethyl-silanediyldiyl-bis-1,1′-(2-methyl-4-phenylindenyl)zirconium dichloride supported on porous SiO 2 , was used. The catalyst was flushed into the prepolymerization reactor with propane feed. Not any cocatalyst or donor were fed. The mean residence time of the catalyst was kept at 9 min. The temperature of the upper part of prepolymerization reactor was 15° C. and the temperature of the lowest part of prepolymerization reactor was 13° C. The morfology of the PP homopolymer was excellent (not any fines). Operability of the process was good.
Example 18 (Comparative)
Procedure was the same as Example 17 but not continuous prepolymerization was used. The catalyst was prepolymerized with propylene (the mass ratio of PP/cat was 1.3) in batch (dry prepolymerization in gas phase), in the product of the loop reactor was lot of fines and loop fouling was observed.
Example 19
As Example 17 but no batch prepolymerization was used.
Example 20 (Comparative)
As Example 19 but no continuous prepolymerization was used.
Example 21
Same as Example 19 but the temperature of the prepolymerization was kept at 25° C. and the residence time of the catalyst was kept at 7 min.
Examples show that in polymerization of polyolefin polymer with highly active and stereospecific ZN-catalyst the amount of fines can be reduced by using a novel CCSTR as a prepolymerization system compared to traditional batch-wise prepolymerization or a simple CSTR type reactor.
Examples also show that combination or traditional batch-wise prepolymerization and a continues prepolymerization can be useful.
Further more examples show that for fines reduction a short time pipe prepolymerization was not useful even in producing as low MFR as 2.5 g/10 min.
TABLE I
Batch
Reactor
Temp.
Prepol. time
2.0 mm
1.0 mm
0.5 mm
0.18 mm
Fines
BD
Example
prepolym.
type
° C.
min
%
%
%
%
%
g/m 3
1
No
CCSTR
20
3
4.9
34.6
32.3
25.2
3.1
0.44
2 (Comp.)
No
CSTR
20
3
2.3
23.1
30.5
36.4
7.7
0.40
3
No
CCSTR
20
3
9.3
32.2
31.3
23.4
4.0
0.40
4
No
CCSTR
20
4
9.6
49.2
21.9
16.9
2.5
0.45
5 (Comp.)
No
CSTR
20
4
6.2
35.2
27.4
22.8
8.4
0.41
6
No
CCSTR
20
2
3.7
36.2
32.5
24.2
3.3
0.43
7 (Comp.)
No
—
—
—
0.2
12.2
49
33.1
5.3
0.36
8
Yes
CSTR
20
3
0.3
12.9
58.3
26.2
2.4
0.40
TABLE II
Batch
Reactor
Temp.
Prepol. time
2.0 mm
1.0 min
0.5 mm
0.18 mm
Fines
BD
Example
prepolym.
type
° C.
min
%
%
%
%
%
g/m 3
9
No
CCSTR
20
5
2.9
56.4
21.7
14.0
4.9
0.55
10 (Comp.)
Yes
—
—
—
12.8
43.3
17.0
14.3
12.6
0.46
TABLE III
Batch
Reactor
Temp.
Prepol. time
2.0 mm
1.0 mm
0.5 mm
0.18 mm
Fines
BD
Example
prepolym.
type
° C.
min
%
%
%
%
%
g/m 3
11 (Comp.)
Yes
—
—
—
2.7
26.2
54.3
16.1
0.7
0.41
12 (Comp.)
Yes
PIPE
0
20
3.7
23.5
58.6
12.6
1.5
0.43
13 (Comp.)
Yes
PIPE
20
20
4.8
30.2
54.1
10.2
0.7
0.44
TABLE IV
Prepol.
Batch
reactor
Temp.
Temp.
Prepol. time
2.0 mm
1.0 mm
0.5 mm
0.18 mm
Fines
Example
Catalyst
prepolym.
type
upper part
lowest part
min.
%
%
%
%
%
BD
15
ZN
no
CCSTR
20
40
7
28.1
40.6
25.2
6.1
0
0.39
16
ZN
no
*CCSTR
20
30
8
16.2
62.2
18
3.6
0
0.3
17
SSC
yes
*CCSTR
15
13
9
Excellent morfology, not any fines. Good operability.
18 (Comp.)
SSC
yes
no continuous prepolymerization was used
Poor morfology, lot of fines. Bad fouling of the loop
reactor walls.
19
SSC
no
*CCSTR
15
13
9
Excellent morfology, not any fines. Good operability.
20 (Comp.)
SSC
no
no continuous prepolymerization was used
Poor morfology, lot of fines. Bad fouling of the loop
reactor walls.
21
SSC
no
*CCSTR
25
25
7
Excellent morfology, not any fines. Good operability.
*two compartments and three vertical equalizing grids
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A process for polymerization of olefin monomers by forming a fluid stream containing catalyst, continuously feeding the fluid stream into an elongated polymerization reactor having at least two successive chambers separated by dividing plates having a diameter slightly smaller than that of the polymerization rector, feeding monomers, and an optional catalyst and donor into the polymerization reactor under temperature conditions to polymerize the olefin while maintaining a mixed flow in the chambers to polymerize the monomers and optional comonomer in the fluid, and removing the resultant polymer slurry from the polymerization reactor.
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RELATED APPLICATION INFORMATION
This application is a continuation-in-part of U.S. application Ser. No. 07/780,151 filed Oct. 21, 1991 now U.S. Pat. No. 5,157,790.
BACKGROUND OF THE INVENTION
The present invention relates to work garments and, more particularly, garments having orthopedic components for reducing the strain of a wearer when encountering heavy loads.
Many work-related activities require a worker to lift and carry heavy objects causing strain in the lower back area of the worker. A typical work garment, such as a coverall, provides little means for supporting the lower back area of a worker while performing his duties. The objective of a coverall is rather to provide a barrier between the worker's clothing and the work area to prevent the worker's clothing from being soiled.
A work garment having a particularly specialized application is a firefighter garment. A typical firefighter garment includes a pant and jacket, each having an outer shell of a fire-resistant aramid fiber such as NOMEX or KEVLAR (NOMEX and KEVLAR are trademarks of E. I. Dupont de Nemours & Co., Inc.) and an inner liner having a moisture barrier component and a thermal barrier component. The moisture barrier may be GORTEX material (GORTEX is a trademark of W. L. Gore & Associates, Inc.) and the thermal barrier may be a felt of aramid fibers. The inner liner components typically are quilted together, and the inner liner is separable from the outer shell to facilitate laundering of the garment.
The firefighter pant typically is beltless and is held in position by suspenders which fit under the jacket. The inner pant liner and outer pant shell snap or button together and the suspender ends or tabs may attach to such buttons or snaps, or may be attached by separate means. Both the jacket and the pant are loose fitting and somewhat baggy to allow freedom of movement.
While such firefighter garments provide adequate protection against such hazards as heat, water and flash flame, they, like conventional work garments, provide no protection for the hazard of muscle strain, especially in the lumbar region of the spine of the wearer. In the fighting of fire, the firefighter is called upon to carry heavy equipment such as hoses and ladders, over his shoulder, and occasionally is required to carry an injured person over his shoulder in the well-known "firemen's carry" maneuver. In addition, the firefighter often carries a tank of breathing air strapped to his back. All of these items and activities impose a stress upon the lumbar region of the back which is often an unbalanced imposition of a weight load.
While there are many types of designs for so-called lumbar stabilizers, such as the stabilizer disclosed in Porterfield, et al. U.S. Pat. No. 4,794,916 and Miller U.S. Pat. No. 4,991,573, such devices are designed to provide comfort and reduce stress to an individual who has sustained an injury in the lumbar area of the spine. It is not an object of such devices to provide a prophylactic benefit to a wearer in a typical work environment or in the hazardous environment of a firefighter. Further, such devices are designed to be worn independently of any other type of garment and typically are worn underneath the outer garments of a wearer.
It is impractical to require workers and firefighters to keep track of and separately put on such lumbar stabilizers, in addition to other garments and gear, in day-to-day work activities or in the rush to answer an alarm. Accordingly, there is a need for a work garment which provides support for a worker in the lumbar region of the wearer's spine in order to minimize the risk of injury to that region sustained during strenuous work activity.
SUMMARY OF THE INVENTION
The present invention is a work garment with a support which minimizes the stress imposed upon the lumbar region of the spine of the wearer, thereby reducing the likelihood of spinal and muscle injury to workers who must lift or carry heavy loads in the course of their work activities. The support is integral with the garment and can be selectively activated and deactivated so that the support feature is applied only when needed. Another benefit of the invention is the so-called "placebo effect," wherein the mere presence of the invention in a work garment makes the wearer self-conscious of his lifting form, and thereby serves to encourage use of good lifting form.
In one preferred embodiment of the invention, the garment is a coverall having a waist portion coverinq the lower back area of the wearer, including the lumbar region, and a support member, attached to the inside surface of the coverall for supporting the lumbar region of the wearer. The support member includes a plurality of elastic bands which encircle the waist of the wearer and includes a closure mechanism in the front of the wearer adjacent to the coverall closure. The elastic bands support a contact member positioned adjacent the lumbar region of the spine, which ensures proper alignment of the lumbar vertebrae during bending and lifting. The contact member is a resilient pad positioned over the lumbar vertebrae.
The closure member of the elastic bands allows the wearer to activate the support member by connecting the closure member, thereby applying a radially inward pressure against the lumbar region, or deactivate the support member by disconnecting the closure member to relax the elastic bands. Accordingly, the support member can be worn comfortably at all times and activated only when needed during strenuous work activity.
In an alternate embodiment of the invention, the garment is a firefighter pant having an inner liner with a thermal layer and an outer shell having a waist portion covering the lower back area of the wearer, including the lumbar region, and a support member, attached to the shell, for supporting the lumbar region of the wearer. The support member includes a plurality of elastic bands which encircle the waist of the wearer and includes a closure mechanism in the front of the wearer adjacent to the pant closure. The elastic bands support a contact member positioned adjacent the lumbar region of the spine, which ensures proper alignment of the lumbar vertebrae during bending and lifting. In one embodiment, the contact member is a pad positioned over the lumbar vertebrae and in another embodiment, the contact member includes a plurality of flexible, elongated stays which extend vertically in parallel with the lumbar vertebrae. The closure member of the elastic bands allows the wearer to activate and deactivate the support member identically to that of the coverall.
In a second alternate embodiment, the support member includes a girdle made of shell material which encloses the waist of the wearer in the lumbar region and includes inner and outer layers in closing the elastic bands. The girdle includes buttons for connecting to suspenders, and button holes or snaps for connection to the firefighter pant, thereby acting as an integral component of the pant suspension system. Such a girdle is therefore retrofittable to existing firefighter pants. The girdle includes a front closure member, separate from the elastic bands, so that the girdle may be worn comfortably at all times, and the elastic bands adjusted activate it when needed.
Other embodiments in which the present invention can be incorporated is a firefighter's jacket, paramedic uniforms, and other work related garments such as overalls. Any garment worn by a worker whose activities involve lifting or strenuous activity which would require lumbar support would be ideal for incorporating the present invention.
In all of the embodiments, it is preferable to provide closure members consisting of complementary strips of hook and loop material. However, other closure members, such as buckles, snaps and hook-and-D connectors may be used.
Accordingly, it is an object of the present invention to provide a work garment with an integral lumbar support mechanism; a work garment with a lumbar support mechanism which can be activated and de-activated easily as needed to ensure wearer comfort at all times; a work garment with integral lumbar support mechanism for a work garment which does not add significantly to the weight of the work garment; and a work garment with a lumbar support mechanism which is relatively inexpensive to incorporate into the garment, or can be provided as an integral component retrofitted to an existing garment design.
Other objects and advantages of the present invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a somewhat schematic, perspective view of a first alternate embodiment of the invention showing a firefighter pant embodying the present invention;
FIG. 2 is a detail of the pant of FIG. 1, showing the underside of the ends of the straps;
FIG. 3 is a detail of the pant of FIG. 1 showing an end of the support member attached to the pant in the first step of activation;
FIG. 4 is the detail of FIG. 3 showing the support member fully activated;
FIG. 5 is a detail of a second alternate embodiment of the invention showing a girdle incorporating the support member;
FIG. 6 is the alternate embodiment of the invention of FIG. 4 retrofitted to a pant;
FIG. 7 shows a third alternate embodiment of the invention in which the pant of FIG. 1 has been modified to include a contact pad;
FIG. 8 is a schematic, perspective view of a fourth alternate embodiment of the invention showing a firefighter jacket incorporating the support member;
FIG. 9 is a horizontal cross-sectional view taken along line 9--9 of FIG. 8 showing the support member;
FIG. 10 is a vertical cross-sectional view taken along line 10--10 of FIG. 9 showing the elastic strap means;
FIG. 11 is a vertical cross-section view taken along line 11--11 of FIG. 9 showing the support member;
FIG. 12 is a sectional view taken along line 12--12 of FIG. 9 showing the attachment means for the contact member;
FIG. 13 is a schematic, perspective view of a preferred embodiment of the invention showing a coverall incorporating the support member;
FIG. 14 is a horizontal cross-sectional view taken along line 14--14 of FIG. 13 showing the support member;
FIG. 15 is a vertical cross-sectional view taken along line 15--15 of FIG. 14 showing the support member; and
FIG. 16 is a vertical cross-sectional view taken along line 16--16 of FIG. 14 showing the elastic strap means.
DETAILED DESCRIPTION
As shown in FIGS. 1 and 2, an alternate embodiment of the present invention is a firefighter garment, generally designated 10, which is a pant having an outer shell 12 made of a woven aramid fiber such as NOMEX or KEVLAR. The outer shell includes a front closure 14 which is secured by snaps 16. The pant 10 includes an inner liner 18 having an outer moisture barrier quilted to a batting of NOMEX fibers. The inner liner 18 is shaped to fit within the outer shell 12 and is attached to the outer shell at the waistline by snaps 22. The liner 18 includes suspender buttons 23 which protrude through the shell 12.
The waist portion 24 of the garment includes a support member, generally designated 26. The support member includes upper and lower elastic straps 28, 30, respectively. The waist portion 24 and support member 26 are positioned on the pant 10 to encircle the midriff of a wearer, and the rear portion of the support member is positioned to lie adjacent to the lumbar region of the spine of the wearer.
Adjacent ends of the straps 28, 30 are connected by closure tabs 32, 34, and each of the tabs has attached to its underside a hook component 35 of a hook and loop closure mechanism. Similarly, straps 28, 30 include strips 36 of hook material. The outer shell 12 includes complementary strips 38, 39 loop material, and the outer surfaces of the straps 28, 30 adjacent tabs 32, 34 include squares 40 of loop material (see also FIG. 4).
The straps 28, 30 extend through slits 41, 42 formed in the outer shell which, at the waist portion 24, includes inner retainer squares 43 of shell material stitched to the outer shell. The portions of straps 28, 30 extending between slits 41, 42 extend between the squares 43 and shell 12. The straps 28, 30 support a plurality of oblong, vertically-extending stays 44, secured by hook and loop connections 45 to the radially inner surface of the straps. The straps preferably are made of a rigid plastic material such as nylon. The straps 28, 30 are secured to the rear of the waist portion 24 by stitching 46 and the stays 44 are positioned to lie on either side of the lumbar vertebrae of a wearer.
As shown in FIG. 1, the rear portion 48 of the waist portion 24 of the pant 10 is raised, relative to the front portion of the pant, to ensure that a sufficient portion of the lumbar region of the wearer is contacted by the stays 44.
The method of activating the support member 26 is shown sequentially in FIGS. 1, 3, and 4. FIG. 1 shows the support member in a de-activated configuration; that is, the tabs 32, 34 are not attached to each other and accordingly, the straps 28, 30 do not exert an inward constrictive force on the mid-section of a wearer. Preferably, tabs 32, 34 are attached to panels 38 of loop material adjacent to slits 41, 42 (see FIG. 2).
As shown in FIG. 3, in order to activate the support member 26, tab 32 is brought over to panel 39 so that the panels 35 and/or 36 on tab 32 and/or straps 28, 30 (see FIG. 2) contact panel 39, thereby attaching the tab to the pant 10 at the position of panel 39. Next, as shown in FIG. 4, tab 34 is superposed to squares 40 so that panel 36 on tab 34 is brought into contact with the squares 40 to make a connection and fix the tab 34 relative to the squares. Accordingly, the pant 10 shown in FIG. 4 is in an activated configuration in which the ends of the straps 28, 30 are in an overlapping relation and are tightened about the waist of a wearer, thereby urging the stays 44 into the lower back of the wearer in the lumbar region, preferably on either side of the lumbar vertebrae. This constrictive pressure supports the back of the wearer and reduces the likelihood of back injury due to heavy or unbalanced lifting.
The adjustment of the support member 26 from the activated configuration shown in FIG. 4 to the de-activated configuration shown in FIG. 1 is simply the reverse of the aforementioned steps. The tab 34 is pulled away from the straps 28, 30, thereby separating the hook and loop panels from each other, and the tab is allowed to retract to its normal position. Tab 32 is then separated from the shell 12, thereby separating the hook and loop closure panels on the tab and pant shell 12 at that point, and straps 28, 30 are allowed to retract to their unstretched positions. The tabs 32, 34 then assume the configuration shown in FIG. 1. It is anticipated that a firefighter wearing the pant 10 of the present invention would wear the pant principally in a de-activated configuration, as shown in FIG. 1, then adjust the support member 26 to the activated configuration of FIG. 4 before fighting a fire or engaging in heavy lifting.
A second alternate embodiment of the invention is shown in FIGS. 5 and 6. In FIG. 5, the support member 26' includes a girdle 50 made of inner and outer layers 52, 54 of shell material stitched together at their peripheries. The girdle 50 includes a front closure 56 which includes complementary panels 58, 60 of hook and loop material to secure the girdle when worn.
The straps 28, 30 are attached at their ends to tabs 32', 34', each of which has a panel of hook and loop material 62, 64 attached to it.
The girdle 50 includes snaps 66 about its lower periphery and suspender buttons 68 attached to about its upper periphery. As shown in FIG. 6, the girdle 50 is attached to a firefighter pant 10' by engagement of the girdle with complementary snaps 70 mounted on the outer shell and complementary snaps 72 mounted on the inner liner 18'. A pair of standard firefighter suspenders 74 are then attached to the buttons 68 of the girdle 50 to complete the pant 10' construction. In order to activate the girdle 50, panel 32' is stretched to contact the exposed portion of panel 58 of the girdle and is attached by means of the hook and loop connection between those components. The tab 34' is then stretched and attached to the back side of tab 32' so that the complementary hook and loop panels of those components engage. When this connection is effected, the stays 44 are urged into the lumbar region of the back of the wearer by the constrictive force of the straps 28, 30.
A third alternate embodiment 10" having a modified support member 26" is shown in FIG. 7. In this embodiment, the support member 26" is identical in all respects to the support member 26 of FIGS. 1-4, except that the stays 44 have been replaced by a lumbar pad 76. The lumbar pad 76 is made of a thick, hard foam and is approximately 8 inches long, 6 inches wide, and 1/2 inch thick. The pad 76 is attached by hook and loop connections 78 to the straps 28, 30 of the support member 26". Accordingly, den the support member 26" of the pant 10" shown in FIG. 7 is activated, the straps 28, 30 urge the pad 76 into the lumbar vertebrae of the wearer to provide support for lifting and bending movement.
As shown in FIG. 8, a fourth alternate embodiment of the invention is a firefighter jacket 100. The jacket 100 includes an outer shell 102 made of a woven aramid fiber and which includes a front closure 104 secured by a slide fastener 106 and hook and loop closure components 108. The jacket 100 includes an inner liner 110 having an outer moisture barrier 111 (see FIG. 10) attached to a thermal liner 112 of NOMEX material. The inner liner 110 is shaped to fit within the outer shell 102 and is attached to the outer shell along the front closure 104 by snaps (not shown). The jacket 100 includes a torso portion 113 having a waist segment 114 which covers a lower back area of a wearer.
The waist segment 114 of the jacket 100 includes a support member, generally designated 116. The support member includes upper and lower elastic straps 118, 120, respectively. The waist segment 114 and support member 116 are positioned on the jacket 100 to encircle the midriff of a wearer, and the rear portion of the support member is positioned to lie adjacent to the lumbar region of the spine of the wearer.
Adjacent ends of the straps 118, 120 are attachable to each other by closure tabs 122, 124, and each of the tabs has attached to its underside a hook component 126 of a hook and loop closure mechanism. Similarly, straps 118, 120 include strips 128 of hook material attached to their undersides and strips 130 of loop material attached to their outer surfaces. The outer shell 102 includes complementary strips 132 of loop material.
The straps 118, 120 extend through slits 134, 136 respectively, formed in the outer shell 102 which, at the waist segment 114, include inner retainer squares 138 of shell material stitched to the inside surface of the outer shell. Portion of straps 118, 120 between slits 134, 136 extend between the squares 138 and shell 102 as shown in FIGS. 9 and 10.
A lumbar pad 140 made of a thick, hard foam similar to pad 76 in embodiment 10" is located in the back of the waist segment 114 to support the lumbar vertebrae of the wearer. Pad 140 is removably attached to the inside surface of the outer shell 102 by hook and loop fasteners. A hook strip 142 is applied to the back of the pad and two loop strips 144, 146 are stitched to the outer shell. The inner liner 110 covers the front of the lumbar pad 140 (also shown in FIG. 11).
The method of activating the support member 116 is similar to the embodiments of FIGS. 1-7 in that tab 122 brought over the loop strip 132 so that hook strips 126 and/or 130 on tab 122 and/or straps 118, 120 contact loop strip 132, thereby attaching the tab and/or the elastic straps. Next, tab 124 is brought over to hook strips 128 on the upper and lower elastic straps to make a connection and fix the tab 124 relative to the loop strip 132. Accordingly, the jacket is in an activated configuration in which the ends of the straps 118, 120 are in an overlapping relation and are tightened about the waist of a wearer, thereby urging the lumbar pad 140 into the lower back of the wearer in the lumbar region. This constrictive pressure supports the back of the wearer and reduces the likelihood of back injury due to heavy or unbalanced lifting.
The adjustment of the support member 116 from the activated configuration shown in FIG. 9 to the deactivated configuration shown in FIG. 8 is simply the reverse of the aforementioned steps.
Depending upon the waist size of the wearer, the tension of the upper and lower elastic straps 118, 120 may be adjusted. As shown in FIG. 12, the tension in the elastic straps 118, 120 can be adjusted through the incorporation of buckles 148, 150 and 152. Buckles 148 and 152 are attached to straps 118, 120 by looping the end of the strap over the center rung of the buckle and sewing the end over upon itself. Straps 118 and 120 are then threaded through the outside rungs of bucket 150 which is positioned between loop strips 144, 146 by loop 154, which is a portion of outer shell material looped over the center rung of buckles 150 and sewn to outer shell 102. Straps 118, 120, after being threaded through the outer rung of buckles 150, are then directed back toward buckles 148 and 152 and threaded between the outer rungs of buckles 148 and 152 over the center rung. The tension of the straps 118, 120 can then be adjusted by moving buckles 148 and 152 axially along the strap to shorten or lengthen the strap to the desired length.
In addition to firefighter garments, any garment worn which involves lifting or strenuous activity and requires lumbar support, particularly work garments, can be modified into the present invention. The preferred embodiment of the invention is shown in FIG. 13 which is a representative work garment known as a coverall 160. Coverall 160 is made of a sturdy cloth material such as cotton, polyester, or a cotton/polyester blend. The coverall 160 includes a front closure 162 which is secured by a slide fastener 164, or alternatively by snaps.
The coverall 160 includes a waist segment 166 wherein the support member 168 is located. The support member 168 is identical to the support member of the previous embodiment and includes upper and lower elastic straps 170, 172, respectively. The waist segment 166 and support member 168 are positioned on the coverall to encircle the midriff of a wearer, and the rear portion of the support member is positioned to lie adjacent to the lumbar region of the spine of the wearer.
Adjacent ends of the straps 170, 172 are connected by closure tabs 174, 176, and each of the tabs has attached to its underside a hook component 178 of a hook and loop closure mechanism. Straps 170, 172 include strips 180 of hook material located on the underside surface of the straps directly underneath strips of loop material 182 located on the outer surface of the straps. The outer surface of the coverall also includes complementary strips 184 of loop material.
The straps 170, 172 extend through slits 186, 188 formed in the coverall 160 which, at the waist portion, includes inner retainer squares 190 of coverall material stitched to the inner surface of the coverall. Inner retainer squares 190 extend around the waist segment 166 and terminate behind the lumbar pad 192 as also shown in FIG. 14. The portions of straps 170, 172 extending between slits 186, 188 extend between the squares 190 and coverall 160 as shown in FIG. 16. Straps 170, 172 support the lumbar pad 192 which is secured by hook and loop connections 194, 196 respectively, as shown in FIG. 15. Hook strip 194 is attached to the back side of lumbar pad 192, and loop strips 194 are attached to the inside surface of the coverall 160. Besides being retained by hook and loop fasteners, the lumbar pad 192 is also held in place by a pad retainer square 198 made of coverall material which is stitched to the inside surface of the coverall 160 and covers the pad. Retainer square 192 is located in between the pad 192 and the wearer.
The method for activating and de-activating the support member 168 is identical to that described for the previous embodiment. The support member 168 of the coverall 160 includes buckles 200, 202, and 204 similar to the firefighter jacket for adjusting the tension of elastic straps 170, 172 which is dependent upon the waist size of the wearer.
Other closure means in all the embodiments may be used to adjust the support member to an activated configuration. For example, the hook and loop attachment panels may be replaced with other mechanical attachment mechanisms such as a perforated belt and buckle or a hook and D connection. However, the hook and loop connection is preferred because of the ease of attachment and removal.
While the forms of apparatus herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention.
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A work garment having a waist portion covering a lower back area of a wearer and a front closure, and a support member, attached to the garment, for supporting a lumbar region of the wearer. The support member preferably includes a plurality of elastic bands extending about the waist portion of the garment and having complementary closure members positioned adjacent to the front closure of the work garment, and a contact member, attached to the elastic straps, positioned to contact the lumbar region of the wearer. In one embodiment, the elastic straps are integral with the work garment, which may be a coverall, and in other embodiments with firefighter garments such as a jacket, pant, and girdle. In one embodiment, the contact member consists of a resilient pad centered in the lumbar area of the wearer, and in another embodiment, the contact member consists of a plurality of elongate, vertically-extending stays.
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PRIORITY
[0001] This application is a divisional of, and claims priority from, U.S. Ser. No. 13/343,059 filed on Jan. 4, 2012.
FIELD
[0002] The present disclosure relates to environmental control systems and methods for aircraft with pressurized cabins and, more particularly, to aircraft environmental control systems and methods that utilize dedicated cabin air compressors to compress air.
BACKGROUND
[0003] Bleed air, or compressed air obtained from within an aircraft's main engines, has traditionally been used to pressurize the aircraft cabin and cargo hold. However, the temperature of this compressed air is typically much higher than required and must be cooled prior to its injection into the cabin. Cooling bleed air in older aircraft required a vapor cycle refrigeration system, which was heavy, expensive and required excessive maintenance. More modern aircraft have eliminated the vapor cycle refrigeration by replacing it with an air cycle system. In addition to an air cycle system, a series of ducts, valves and other heavy equipment requiring intensive maintenance are required to operate this system. Thus, this system is also large, complex, not energy efficient, can overtax the main engine compressors, and results in poor fuel consumption by the aircraft.
[0004] Current technological advances have overcome drawbacks presented by bleed air systems by utilizing dedicated separate cabin air compressors to provide compressed air to the aircraft cabin and cargo ventilation systems that is not sourced from the main engines of the aircraft. The pressurized air sourced from these dedicated cabin air compressors is matched to the required pressure so the system is able to operate with a more modest refrigeration system. When warmer air is needed, the compressors can be operated less efficiently to provide warmer air at the same pressure. However, this approach of using additional, large, high speed mechanical equipment, such as separate cabin air compressors, adds excess weight, reliability and complexity challenges to the aircraft.
[0005] Given the benefits and drawbacks presented by both types of existing technology, there exists a need for an airplane environmental system that utilizes a single efficient, simple, lightweight, turbomachine that can be controlled to achieve the desired temperature and flow of air to the cabin without the need for additional mechanical equipment.
SUMMARY
[0006] In one aspect, the disclosed environmental control system may include a turbomachine assembly having a shaft, a motor, a turbine and a compressor, the compressor outputting a compressed air stream, a first valve that splits the compressed air stream into first and second compressed air streams, a heat exchanger to cool the first compressed air stream and output a cooled air stream, a second valve positioned to receive the cooled air stream and split the cooled air stream into first and second cooled air streams, wherein the first cooled stream is expanded in the turbine to produce an expanded air stream that is combined with the second compressed air stream and the second cooled air stream to provide a combined air stream having a temperature and a flow rate, and a controller that communicates control signals to the compressor, the motor and the first and second valves to control the temperature and flow rate of the combined air stream.
[0007] In another aspect, the disclosed environmental control system may include (1) a turbomachine assembly having a compressor, a motor and a turbine, wherein the compressor has a variable compressor geometry and is driven by a shaft to output a compressed air stream, wherein the motor is coupled to the shaft and has a variable motor power, and wherein the turbine is coupled to the shaft; (2) a first valve having a first variable splitting state to selectively divide the compressed air stream into a first compressed air stream and a second compressed air stream; (3) a heat exchanger positioned to cool the first compressed air stream and output a cooled air stream; (4) a second valve having a second variable splitting state to selectively divide the cooled air stream into a first cooled air stream and a second cooled air stream, wherein the first cooled air stream is coupled to the turbine such that the turbine expands the first cooled air stream as the first cooled air stream passes through the turbine, thereby producing an expanded air stream, and wherein the expanded air stream is combined with the second compressed air stream and the second cooled air stream to provide a combined air stream, the combined air stream having a temperature and a flow rate; and (5) a controller configured to control the temperature and the flow rate of the combined air stream by controlling, at least, the variable compressor geometry, the variable motor power, the first variable splitting state and the second variable splitting state.
[0008] In yet another aspect, disclosed is an environmental control method. The method includes the steps of (1) providing a turbomachine assembly comprising a compressor, a motor and a turbine, wherein said compressor has a variable compressor geometry and is driven by a shaft, said motor and said turbine being coupled to said shaft, said motor being configured to selectively supply rotational power to said shaft; (2) obtaining an input air stream; (3) passing said input air stream through said compressor to obtain a compressed air stream; (4) providing a first valve configured to selectively split said compressed air stream into a first compressed air stream and a second compressed air stream; (5) cooling said first compressed air stream to obtain a cooled air stream; (6) providing a second valve configured to selectively split said cooled air stream into a first cooled air stream and a second cooled air stream; (7) passing said first cooled air stream though said turbine to obtain a turbine output stream, wherein said step of passing said first cooled air stream through said turbine supplies rotational power to said shaft; (8) combining said turbine output stream with said second cooled air stream and said second compressed air stream to obtain a combined air stream, said combined air stream having a temperature and a flow rate; and (9) controlling said compressor geometry, said motor, said first valve and said second valve to minimize a first difference between said temperature and a target temperature and a second difference between said flow rate and a target flow rate.
[0009] Other aspects of the disclosed environmental control system and method will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic representation of a first embodiment of the disclosed aircraft environmental control system;
[0011] FIG. 2 is a schematic representation of a second embodiment of the disclosed aircraft environmental control system;
[0012] FIG. 3 is a schematic representation of a third embodiment of the disclosed aircraft environmental control system; and
[0013] FIG. 4 is a flow chart depicting one aspect of the disclosed environmental control method.
DETAILED DESCRIPTION
[0014] Referring to FIG. 1 , a first embodiment of the disclosed aircraft environmental control system, generally designated 100 , may include a compressor 102 , a motor 104 , a turbine 106 , first and second valves 108 , 110 , a heat exchanger 112 , temperature sensors 114 , 116 , 118 , 120 , pressure sensors 122 , 124 , 126 , flow sensors 128 , 130 and a controller 132 . Additional components, such as additional temperature, pressure and flow sensors, may be included as part of the disclosed aircraft environmental control system 100 without departing from the scope of the present disclosure.
[0015] The compressor 102 , the motor 104 and the turbine 106 may be assembled as a turbomachine assembly 134 . Specifically, the compressor 102 may be driven by a shaft 136 , and both the motor 104 and the turbine 106 may supply rotational power to the shaft 136 . Therefore, the motor 104 may only be required to draw electrical power sufficient to make up the difference between the rotational power supplied by the turbine 106 and the desired amount of rotational power to be supplied to the compressor 102 .
[0016] The compressor 102 may be a variable geometry air compressor. Therefore, the geometry of the compressor 102 may be actively controlled in response to control signals (communication line 138 ) received from the controller 132 . However, use of a fixed geometry compressor is also contemplated.
[0017] The motor 104 may be an electric motor or the like, and may selectively supply rotational power to the shaft 136 to drive the compressor 102 . The amount of power supplied by the motor 104 to the shaft 136 may be controlled by the controller 132 , which may communicate control signals (communication line 140 ) to the motor 104 .
[0018] The turbine 106 may be a fixed geometry turbine, and may supply rotational power to the shaft 136 to drive the compressor 102 . However, use of a variable geometry turbine is also contemplated. Those skilled in the art will appreciate that use of a variable geometry turbine may introduce another parameter (turbine geometry) that may be controlled by the controller 132 to achieve the desired output.
[0019] The controller 132 may be any apparatus or system capable of generating control signals for controlling the compressor 102 , the motor 104 , the turbine 106 , and the first and second valves 108 , 110 based on input signals received from the temperature sensors 114 , 116 , 118 , 120 , the pressure sensors 122 , 124 , 126 , and the flow sensors 128 , 130 to achieve a cabin air stream 176 having the desired temperature and flow rate. For example, the controller 132 may be a computer processor or the like that has been pre-programmed with one or more control algorithms configured to control the cabin air stream temperature and flow rate.
[0020] An input air stream 150 may be supplied to the compressor 102 , where it may be compressed and output as a compressed air stream 152 . The input air stream 150 may come from a ram air duct.
[0021] The input air stream 150 will be at a temperature and pressure. The pressure sensor 122 may sense the pressure of the input air stream 150 , and may communicate to the controller 132 a signal indicative of the pressure of the input air stream 150 by way of communication line 156 . The compressor 102 inlet temperature may be determined from the compressor inlet pressure sensed by pressure sensor 122 and airplane data typically available to the controller 132 . Alternatively, the compressor 102 inlet temperature may be measured directly by way of optional temperature sensor 114 , which may communicate to the controller 132 a signal indicative of the temperature of the input air stream 150 by way of communication line 154 .
[0022] The temperature and pressure of the input air stream 150 depend on the source of the input air stream 150 and/or the ambient conditions. For example, when the aircraft is on a tarmac in a warm climate, the temperature and pressure of the input air stream 150 may be relatively higher than when the aircraft is moving at altitude. Therefore, the signals (communication lines 154 , 156 ) received by the controller 132 may be used by the controller 132 to generate control signals.
[0023] The compressed air stream 152 output by the compressor 102 may be at a temperature and pressure, which may be measured by temperature sensor 116 and pressure sensor 124 . The temperature sensor 116 may communicate to the controller 132 a signal indicative of the temperature of the compressed air stream 152 by way of communication line 158 . The pressure sensor 124 may communicate to the controller 132 a signal indicative of the pressure of the compressed air stream 152 by way of communication line 160 .
[0024] The flow rate of the compressed air stream 152 output by the compressor 102 may be measured by the flow sensors 128 , 130 . While a dedicated flow sensor is not shown on the compressed air stream 152 , those skilled in the art will appreciate that the flow rate of the compressed air stream 152 may be derived by totaling the flow rates measured by both flow sensor 128 and flow sensor 130 . The flow sensors 128 , 130 may communicate to the controller 132 signals indicative of the measured flow rates by way of communication lines 162 , 164 .
[0025] The flow sensors 128 , 130 may optionally include pressure and temperature information. For example, the flow sensors 128 , 130 may be venturi or turbine flow sensors, which may require pressure and temperature information to obtain a reliable measurement. However, flow sensors that do not require pressure and temperature information, such as anemometer flow sensors, are also contemplated.
[0026] Thus, the temperature, pressure and flow rate of the compressed air stream 152 may be dictated by, among other things, the geometry of the compressor 102 and the rotational power supplied to the compressor 102 by the shaft 136 , both of which may be controlled by the controller 132 .
[0027] The compressed air stream 152 may be split at the first valve 108 into a heat exchanger stream 166 and a heat exchanger bypass stream 168 . The first valve 108 may be controlled by the controller 132 by way of communication line 170 . The control signal communicated by the controller 132 to the first valve 108 may control the split between the heat exchanger stream 166 and the heat exchanger bypass stream 168 . Therefore, the first valve 108 may control the division of the flow between the heat exchanger stream 166 and the heat exchanger bypass stream 168 .
[0028] Optionally, the first valve 108 (or an additional valve unit) may also control the total impedance across the first valve 108 . Therefore, by controlling the impedance, the first valve 108 may control the flow rate downstream of the first valve 108 .
[0029] The heat exchanger bypass stream 168 may bypass the heat exchanger 112 , and may be combined with the turbine output stream 172 and the turbine bypass stream 174 at combination point 180 . The combination of the heat exchanger bypass stream 168 , the turbine output stream 172 and the turbine bypass stream 174 may form the cabin air stream 176 , which may flow into the cabin 178 .
[0030] The heat exchanger bypass stream 168 will have a temperature, a pressure and a flow rate. The temperature of the heat exchanger bypass stream 168 may be substantially the same as the temperature of the of the compressed air stream 152 , though additional temperature and pressure sensors (not shown) may be provided on the heat exchanger bypass stream 168 without departing from the scope of the present disclosure. The flow rate of the heat exchanger bypass stream 168 may be measured by flow sensor 130 . Flow sensor 130 may communicate to the controller 132 a signal indicative of the flow rate of the heat exchanger bypass stream 168 by way of communication line 164 .
[0031] The heat exchanger stream 166 may pass through the heat exchanger 112 . The heat exchanger 112 may cool the heat exchanger stream 166 and may output a cooled stream 182 . The heat exchanger 112 may be any apparatus or system capable of cooling the heat exchanger stream 166 . For example, the heat exchanger 112 may be capable of cooling the heat exchanger stream 166 approximately to ambient conditions.
[0032] The cooled stream 182 may exit the heat exchanger 112 at a temperature, pressure and flow rate, which may be measured by temperature sensor 118 and flow sensor 128 . The temperature sensor 118 may communicate to the controller 132 a signal indicative of the temperature of the cooled stream 182 by way of communication line 184 . The flow sensor 128 may communicate to the controller 132 a signal indicative of the flow rate of the cooled stream 182 by way of communication line 162 . The pressure of the cooled stream 182 may be substantially the same as the pressure of the compressed air stream 152 , though an additional pressure sensor (not shown) may be provided on the cooled stream 182 without departing from the scope of the present disclosure.
[0033] Thus, the controller 132 may communicate control signals to the first valve 108 by way of communication line 170 to control the flow rates of the heat exchanger stream 166 and the heat exchanger bypass stream 168 . Additionally, the control signals communicated to the first valve 108 may control the split between the heat exchanger stream 166 and the heat exchanger bypass stream 168 , thereby controlling the amount (e.g., percentage) of the compressed air stream 152 that is cooled by the heat exchanger 112 .
[0034] The cooled stream 182 may be supplied to the second valve 110 , which may split the cooled stream 182 into a turbine input stream 186 and the turbine bypass stream 174 . The second valve 110 may be controlled by the controller 132 by way of communication line 188 . The control signal communicated by the controller 132 to the second valve 110 may control the split between the turbine input stream 186 and the turbine bypass stream 174 . Therefore, the second valve 110 may control the flow rate downstream of the second valve, as well as the division of the flow between the turbine input stream 186 and the turbine bypass stream 174 .
[0035] The turbine bypass stream 174 may bypass the turbine 106 , and may be combined with the turbine output stream 172 and the heat exchanger bypass stream 168 at combination point 180 .
[0036] The turbine bypass stream 174 may have a temperature, which may be substantially the same as the temperature of the cooled stream 182 . However, additional temperature, pressure and flow sensors (not shown) may be provided on the turbine bypass stream 174 without departing from the scope of the present disclosure.
[0037] The turbine input stream 186 may pass through the turbine 106 . The turbine 106 may expand the turbine input stream 186 , thereby outputting a cooled turbine output stream 172 . The energy extracted by the turbine 106 from the turbine input stream 186 is supplied to the shaft 136 to drive the compressor 102 .
[0038] The turbine output stream 172 may be combined with the turbine bypass stream 174 and the heat exchanger bypass stream 168 at combination point 180 to form the cabin air stream 176 , which may be supplied to the cabin 178 .
[0039] The cabin air stream 176 may enter the cabin 178 at a controlled temperature and flow rate. The temperature of the cabin air stream 176 may be measured by temperature sensor 120 , which may communicate to the controller 132 a signal indicative of the measured temperature by way of communication line 190 . The flow rate of the cabin air stream 176 may be derived from the total flow measured by both flow sensors 128 , 130 , though a dedicated flow sensor (not shown) may be provided on the cabin air stream without departing from the scope of the present disclosure.
[0040] Thus, the controller 132 may control both the temperature and the flow rate of the cabin air stream 176 . Specifically, the controller 132 may generate control signals and may communicate (by way of communication lines 138 , 140 , 170 , 188 ) the control signals to the compressor 102 , the motor 104 , the first valve 108 and the second valve 110 based on input signals received (by way of communication lines 154 , 156 , 158 , 160 , 162 , 164 , 184 , 190 ) from the temperature sensors 114 , 116 , 118 , 120 , the pressure sensors 122 , 124 , 126 , and the flow sensors 128 , 130 . The controller 132 may also ensure that the pressure of the cabin air stream 176 is greater than the pressure of the cabin 178 to ensure positive airflow into the cabin 178 .
[0041] An outflow valve 194 may control the flow rate of the outflow stream 196 from the cabin 178 , thereby maintaining the desired pressure within the cabin 178 . A separate cabin pressure controller 193 may be provided to control the pressure in the cabin 178 by controlling the outflow valve 194 based on cabin pressure signals supplied to the controller 193 by the cabin pressure sensor 126 . Controlling the cabin pressure with only one controller is also contemplated.
[0042] Referring to FIG. 2 , a second embodiment of the disclosed aircraft environmental control system, generally designated 200 , may generally retain the architecture of the system 100 shown in FIG. 1 , but may additionally include a recirculation stream 202 . A recirculation fan 204 may move air along the recirculation stream 202 .
[0043] In one implementation of the second embodiment, the recirculation stream 202 draws air from the cabin 208 , and may combine the recirculation stream 202 with the turbine output stream 210 , the turbine bypass stream 212 and the heat exchanger bypass stream 214 at combination point 216 to form the cabin air stream 218 , which may be supplied to the cabin 208 .
[0044] Other implementations, such as implementations in which the recirculation stream 202 is introduced at other points in the system 200 (i.e., at points other than combination point 216 ), are also contemplated.
[0045] FIG. 3 illustrates a third embodiment of the disclosed aircraft environmental control system, generally designated 300 , which may generally retain the architecture illustrated in FIG. 1 , but may additionally include a water extractor 302 .
[0046] The water extractor 302 may receive the cooled stream 304 from the heat exchanger 306 , and may remove water vapor from the cooled stream 304 . Therefore, the output from the water extractor 302 may be a cooled dry stream 308 , which may be supplied to the second valve 310 .
[0047] While the water extractor 302 is schematically shown as a box in the drawings, those skilled in the art will appreciate that the water extractor 302 may include a recirculation loop that passes through the turbine 312 , which optionally may be a variable geometry turbine.
[0048] Referring to FIG. 4 , also disclosed is a method 400 for controlling the temperature and flow rate of an air stream, such as a cabin air stream supplied to the cabin of an aircraft. As shown at block 402 , the method 400 may begin with the step of providing a turbomachine assembly. The turbomachine assembly may include a compressor, a motor and a turbine. The compressor may have a variable compressor geometry and may be driven by a shaft. The motor and the turbine may both be coupled to the shaft to supply rotational power to the shaft.
[0049] As shown at block 404 , an input air stream may be obtained. Then, as shown at block 406 , the input air stream may be passed through the compressor to obtain a compressed air stream.
[0050] A first valve may be provided, as shown at block 408 . The first valve may be controllable to selectively split the compressed air stream into a first compressed air stream and a second compressed air stream. As shown at block 410 , the first compressed air stream may be cooled, such as by passing the first compressed air stream through a heat exchanger, thereby providing a cooled air stream.
[0051] A second valve may be provided, as shown at block 412 . The second valve may be controllable to selectively split the cooled air stream into a first cooled air stream and a second cooled air stream. As shown at block 414 , the first cooled air stream may be expanded and, thus further cooled, by passing the first cooled air stream through a turbine, thereby providing a turbine output stream. The step of passing the first cooled air stream through the turbine may supply rotational power to the shaft.
[0052] As shown at block 416 , the turbine output stream may be combined with the second cooled air stream and the second compressed air stream to obtain a combined air stream. The combined air stream may have a temperature and a flow rate.
[0053] As shown at block 418 , the compressor geometry, the motor (e.g., the motor power), the first valve (e.g., the splitting state of the first valve) and the second valve (e.g., the splitting state of the second valve) may be controlled to minimize both ( 1 ) a difference between the temperature of the combined air stream and a target temperature and ( 2 ) a difference between the flow rate of the combined air stream and a target flow rate.
[0054] Accordingly, the disclosed environmental control systems and methods may be employed to control the temperature and flow rate of a cabin air stream using a single turbomachine by controlling, among other possible parameters, the compressor geometry, the motor power and the states of the valves.
[0055] Although various aspects of the disclosed environmental control system and method have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.
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An environmental control system including a turbomachine assembly having a shaft, motor, turbine and compressor, the compressor outputting a compressed air stream, a first valve that splits the compressed air stream into first and second compressed air streams, a heat exchanger to cool the first compressed air stream and output a cooled air stream, a second valve positioned to receive the cooled air stream and split the cooled air stream into first and second cooled air streams, wherein the first cooled stream is expanded in the turbine to produce an expanded air stream that is combined with the second compressed air stream and the second cooled air stream to provide a combined air stream having a temperature and a flow rate, and a controller that communicates control signals to the compressor, motor and first and second valves to control the temperature and flow rate of the combined air stream.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink, an ink-jet recording method employing the ink, and an apparatus employing the ink. More particularly, the present invention relates to a recording liquid which provides high density and water resistance of printed letters on non-coated paper such as wood-free paper, paper for copying, bond paper, paper for reporting, and the like, and which provides improved indoor discoloration of an image recorded on coated paper having an image-receiving layer thereon composed of a binder and a pigment. The present invention also relates to an ink-jet recording method, an ink-jet recording unit, an ink-jet recording apparatus, and an ink cartridge.
2. Related Background Art
Heretofore, aqueous inks having a water-soluble dye dissolved in an aqueous medium have been used for ink-jet recording. The inks for such a use are required to have properties as below:
(1) providing sufficient density of images,
(2) having satisfactory drying property on recording mediums,
(3) causing little feathering or running of images,
(4) causing no flowing-out of the recorded images when brought into contact with water, alcohol, or the like, or allowing satisfactory decipherment even when some flowing out occurs (water-resistance),
(5) providing high light-fastness of recorded images,
(6) causing no clogging of a tip of a pen or a nozzle,
(7) causing no inconvenience in printed images such as blurring and scratching in continuous recording or at the re-start of recording after a long term of intermission of the recording (ejection stability),
(8) being stable during storage,
(9) causing no problem on contact with a constituting member of a recording means on use,
(10) giving no hazard to an operator,
and so forth.
Furthermore, in an ink-jet recording system, utilizing thermal energy, the property below is required in addition to the above requirements:
(11) having high heat resistance, and giving no adverse influence to a thermal energy-generating means.
As a specific example of the dye, C.I. Food Black 2 is mainly used in ink-jet recording for both mono-color and full-color images (see Japanese Patent Application Laid-Open Nos. 59-93766, and 59-93768).
An ink using C.I. Food Black 2 is satisfactory in density of recorded images, but still involves problems on light-fastness and water-resistance of recorded images: such that the black color turns brown on prolonged light exposure or on posting-up of printed matters in proximity to a copying machine, resulting in remarkable deterioration of the image quality, and difficulty in decipherment in test of water-spilling.
An ink is disclosed which has ejection stability, water resistance of images, and other properties improved by introducing at least one specific structural unit into a dye structure in Japanese Patent Application Laid-Open No. 1-135880. Further, a recording liquid of black color is disclosed, in Japanese Patent Application Laid-Open No. 1-193375, which has high affinity to recording mediums, and superior in fixability and water-resistance, giving satisfactory quality of printed letters on an ordinary paper. Furthermore, a recording liquid is disclosed which is improved in ejection stability, and light fastness of images in Japanese Patent Publication No. 62-010274.
The ink is required firstly to have suitability for an employed recording system, and secondly is required to give satisfactory properties of printed matters such as quality and fastness of the images. However, it is considerably difficult to satisfy simultaneously all of the aforementioned various requirements on performances, as understood from the prior art disclosures cited above.
The quality of the printed letters mostly depends on a liquid medium of the ink, although it depends secondarily on properties of the dye itself.
The fastness of the printed matter is directly influenced by the dye properties. In particular, light-fastness is the most important of the fastnesses, and improvement of the light-fastness has been tried as described above.
Another problem is discoloration or color change which has not been noticed but has come to be noticed lately as a consequence of technical progress. The discoloration is especially serious in black ink which is used in a large quantity. In full color images, the image quality deteriorates rapidly by the discoloration.
The discoloration proceeds indoors also without direct sunlight illumination. The discoloration further depends on the kind of a recording medium for forming images thereon, being remarkable on paper containing silica or the like as a pigment. The widely used C.I. Food Black 2 is not free from this problem.
Dyes having satisfactory light-fastness have been sought in order to avoid the disadvantage of C.I. Food Black 2. Consequently, dyes have been found that are satisfactory for use on ordinary paper. However, even the ink causing fewer problems on ordinary paper discolors significantly on coated paper that has an ink-receiving layer formed on a substrate and containing a pigment and a binder for the purpose of improving image quality such as color-developing property of the dyes, sharpness, and resolution. Thus the problem is not solved by merely employing a light-fast dye.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a black ink which has the above generally required properties and provides no discoloration of the image even on coated paper.
Another object of the present invention is to provide an ink-jet recording method and an apparatus employing the ink.
According to an aspect of the present invention, there is provided an ink containing a recording agent and a liquid medium for dissolution or dispersion thereof, the recording agent being a compound represented by the general formula ##STR3## wherein R 1 and R 2 are respectively a radical selected from the group of lower alkyl, lower alkoxy, --NHCOCH 3 , --COOM, and --SO 3 M; R 3 , R 4 , and R 5 are respectively a radical selected from the group of hydrogen, hydroxyl, lower alkyl, lower alkoxy, amino, --SO 3 M, and --COOM; A is ##STR4## R 6 and R 7 are respectively a radical selected from the group of hydrogen, hydroxyl, and lower alkoxy; m is 1 or 2; n is 0 or 1; and M is alkali metal or ammonium.
According to another aspect of the present invention, there is provided an ink-jet recording method for conducting recording by ejecting ink droplets through an orifice onto a recording medium in response to a recording signal, wherein the abovementioned ink is employed.
According to still another aspect of the present invention, there is provided a recording unit having an ink container portion for holding an ink and a head portion for ejecting the ink in droplets, wherein the above-mentioned ink is employed.
According to a further aspect of the present invention, there is provided an ink cartridge having an ink container portion for holding an ink, wherein the above-mentioned ink is employed.
According to a still further aspect of the present invention, there is provided an ink-jet recording apparatus having an ink container portion for holding an ink and a head portion for ejecting the ink in droplets, wherein the above-mentioned ink is employed.
According to a still further aspect of the present invention, there is provided an ink-jet recording apparatus having a head portion for ejecting an ink in droplets, an ink cartridge having an ink container portion for holding the ink, and an ink-supplying portion for supplying the ink from the ink cartridge to the recording head, wherein the abovementioned ink is employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and FIG. 1B are respectively a longitudinal cross-sectional view and a lateral cross-sectional view of a head portion of an ink-jet recording apparatus.
FIG. 2 is an oblique appearance view of a multiple form of the head of FIG. 1.
FIG. 3 is an oblique view of an ink-jet recording apparatus.
FIG. 4 is a longitudinal cross-sectional view of an ink cartridge.
FIG. 5 is an oblique view of a recording unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in more detail by reference to preferred embodiment.
The dyes employed in the present invention are generally a sodium salt of a water-solubility-imparting radical such as sulfonic acid radical or the like. The dye in the present invention, however, is not limited to the sodium salts. Salts of potassium, lithium, ammonium, and organic amines such as alcohol amine also give the similar effect, which are included in the present invention.
Specific examples of the dyes represented by the general formula (I) above are shown below. ##STR5##
The dyes above are produced by a procedure below.
SYNTHESIS EXAMPLE 1
The Exemplified dye No. 1 is synthesized by a conventional manner as described in "Theory and Production in Dye Chemistry" written by Yutaka HOSODA as below.
1-amino-2-ethoxynaphthalene-6-sulfonic acid is diazotized in a conventional manner, and is coupled with J acid at a pH range of from 8 to 9. The product is further diazotized by sodium nitrite and is coupled with dimethoxyaniline. The resulting product is still further diazotized with sodium nitrite. The diazotized solution is added to a neutral aqueous solution of 1-amino-2-methoxybenzene-5-sulfonic acid, and stirred for 4 hours. The resulting dye is salted out by addition of sodium chloride and is collected by filtration. Impurities are eliminated from the product by repetition of dissolution, salting-out, and filtration. Thereafter the product is desalted and purified by means of an ultrafiltration apparatus (made by Sartorius GmbH) to obtain the Exemplified dye No. 1.
SYNTHESIS EXAMPLE 2
The sodium salt type of the Exemplified dye No. 4 is synthesized by repetition of diazotization and coupling reactions in a similar manner as in Synthesis example 1. Subsequently, the sulfonic moieties in the dye molecule are converted to free acid form by means of a strongly acidic ion exchange resin, and then the acid groups are neutralized with monoethanolamine to obtain the Exemplified dye No. 4.
The amount of the aforementioned dye to be used in the ink of the present invention is generally within the range of from 0.1 to 15% by weight, preferably 0.5 to 10% by weight, still more preferably from 0.5 to 6% by weight of the total weight of the ink, although the amount is not specially limited thereto.
A suitable aqueous medium for the ink of the present invention is water, or a mixed solvent composed of water and a water-soluble organic solvent.
The water to be used is preferably deionized water, and not ordinary water containing various ions.
Suitable water-soluble organic solvents to be mixed with water include alcohols having 1 to 5 carbons such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol, etc.; amides such as dimethylformamide, dimethylacetamide, etc.; ketones and ketoalcohols such as acetone, diacetone alcohol, etc.; cyclic ethers such as dioxane, etc.; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, etc.; alkylene glycols having alkylene group of 2 to 6 carbons such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexane triol, thiodiglycol, hexylene glycol, diethylene glycol, etc.; glycerin; lower alkyl ethers of a polyhydric alcohol such as ethylene glycol monomethyl (or monoethyl) ether, diethylene glycol monomethyl (or monoethyl) ether, triethylene glycol monomethyl (or monoethyl) ether, etc.; lower alkyl diethers of a polyhydric alcohol such as triethylene glycol dimethyl (or diethyl) ether, tetraethylene glycol dimethyl (or diethyl) ether, etc.; sulfolane, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and the like.
A suitable organic solvent is selected and used from the above solvents and the like. In particular, glycerin or a polyethylene oxide of a polymerization degree of 3 to 6 is preferable for prevention of clogging with ink; a nitrogen-containing cyclic compound or an ether compound of a polyalkylene oxide is preferable in view of image density and ink ejection stability; and use of a lower alkyl alcohol or a surfactant is preferable in view of frequency responsiveness. Accordingly, the preferable composition of the solvent in the present invention contains a main component as above in addition to water.
The content of the above water-soluble organic solvent in the ink is generally in the range of from 2 to 80% by weight, preferably from 3 to 70% by weight, still more preferably from 4 to 60% by weight of the total weight of the ink.
The amount of water to be used is generally in the range of from 10 to 97.5% by weight, preferably not less than 35% by weight, still more preferably not less than 45% by weight of the total weight of the ink. At a less amount of the water, a low-volatile organic solvent remains in a formed image, which undesirably causes problems of migration of the dye, running or feathering of the formed image.
The ink of the present invention may optionally contain a pH-adjusting agent, a viscosity-adjusting agent, a surface tension-adjusting agent, or the like in addition to the components described above. The pH-adjusting agent includes amines such as diethanolamine, triethanolamine, etc.; inorganic alkali salts including hydroxides such as sodium hydroxide, lithium hydroxide, potassium hydroxide, etc.; organic acid salts such as lithium acetate, etc.; organic acids, mineral acids, and the like.
The ink of the present invention desirably has properties of a viscosity at 25° C. within the range of from 1 to 20 cps, preferably from 1 to 15 cps; a surface tension of not less than 30 dyn/cm, preferably not less than 40 dyn/cm; and pH within the range of from 4 to 10.
As the recording method for the ink of the present invention, effective is an ink-jet recording system. As the recording medium therefor, coated paper is effective to obtain an image with high sharpness and high resolution.
The recording medium used in the present invention may be any of mediums including general-purpose ordinary paper (e.g., wood-free paper, medium-quality paper, and bond paper), coated paper, plastic OHP films, and the like. In particular, use of coated paper will achieve considerable effects. The coated paper, which is generally constructed from wood-free paper as the base material and an ink-receiving layer formed thereon composed of a pigment and a binder, includes in the present invention such paper having an ink receiving layer in which paper fibers of the base material exist mixedly in the ink-receiving layer.
The ink of the present invention is especially suitable for an ink-jet recording method wherein ink is ejected by bubbling of ink caused by thermal energy, because the ink has the characteristics of exceedingly high stability of ink ejection and non-occurrence of a satellite dot. For this use, thermal properties of the ink is sometimes adjusted (e.g., specific heat, thermal expansion coefficient, thermal conductivity, etc.).
The ink of the present invention, which is particularly suitably for an ink-jet recording method for recording by ejecting ink droplets by thermal energy, is naturally useful also for general writing utensils.
The methods and the apparatus suitable for the use of the ink of the present invention are those that provide thermal energy to ink in a cell in a recording head in correspondence with recording signals to form liquid droplets by the thermal energy.
An example of the constitution of the heads, which is a main portion of the apparatus, is shown in FIG. 1A, FIG. 1B, and FIG. 2.
A head 13 is formed by bonding a plate of glass, ceramics, or plastics having a groove 14 with a heat-generating head 15. (The type of the head is not limited to the one shown in the figure.) The heat-generating head 15 is constituted of a protection layer 16 formed of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heat-generating resistance layer 18 formed of nichrome or the like, a heat accumulation layer 19, and a substrate plate 20 having a good heat-releasing property made of alumina or the like.
Ink 21 reaches the ejection orifice 22 (a fine pore), forming a meniscus by action of pressure P not shown in the figure.
On application of an electric signal to the electrodes 17-1 and 17-2, the region designated by a symbol "n" on the heat-generation head 15 generates heat to form a bubble in the ink 21 at the position adjacent thereto. The pressure generated by the bubble pushes out the meniscus 23 and ejects the ink 21, as a recording droplets 24, and the ink droplets fly to a recording medium 25. FIG. 2 illustrates an appearance of a multi-head construction by juxtaposing a multiplicity of heads shown in FIG. 1A. The multi-head is prepared by bonding a glass plate having multi-grooves with a heat-generation head 28 similar to the one described in FIG. 1A.
Incidentally, FIG. 1A is a cross-sectional view of the head 13 along an ink flow path, and FIG. 1B is a cross-sectional view of the head at the line A-B in FIG. 1A.
FIG. 3 illustrates an example of the ink-jet recording apparatus having such a head mounted therein.
In FIG. 3, a blade 61 as a wiping member is held at one end by a blade-holding member. The blade 61 is placed at a position adjacent to the recording region of the recording head, and in this example, is held so as to protrude into the moving path of the recording head. A cap 62 is placed at a home position adjacent to the blade 61, and is constituted such that it moves in the direction perpendicular to the moving direction of the recording head to come into contact with the ejection nozzle face to cap the nozzles. An ink absorption member 63 is provided at a position adjacent to the blade 61, and is held so as to protrude into the moving path of the recording head in a manner similar to that of the blade 61. The aforementioned blade 61, the cap 62 and the absorption member 63 constitute an ejection-recovery section 64, and the blade 61 and the absorption member 63 remove water, dust, and the like from the ink ejecting nozzle face.
A recording head 65 has an ejection energy generation means for ejection, and conducts recording by ejecting ink toward a recording medium opposing to the ejection nozzle face. A carriage 66 is provided for supporting and moving the recording head 65. The carriage 66 is engaged slidably with a guide rod 67. A portion of the carriage 66 is connected (not shown in the figure) to a belt 69 driven by a motor 68, so that the carriage 66 is movable along the guide rod 67 to the recording region of the recording head and the adjacent region thereto.
The constitution of a paper delivery portion 51 for delivery of a recording medium and a paper delivery roller 52 driven by a motor (not shown in the figure) delivers the recording medium to the position opposing to the ejecting nozzle face of the recording head, and the recording medium is discharged with the progress of the recording to paper discharge portion provided with paper-discharge rollers 53.
In the above construction, the cap 62 of the ejection-recovery portion 64 is out of the moving path of the recording head 65, while the blade 61 is made to protrude into the moving path. Therefore, the ejecting nozzle face of the recording head 65 is wiped therewith. The cap 62 moves to protrude toward the moving path of the recording head when the cap 62 comes into contact for capping with the ejecting nozzle face of the recording head.
At the time when the recording head moves from the home position to the record-starting position, the cap 62 and the blade 61 are at the same position as in the above-mentioned wiping time, so that the ejection nozzle face of the recording head is wiped also in this movement.
The recording head moves to the home position not only at the end of the recording and at the time of ejection recovery, but also at a predetermined interval during movement for recording in the recording region. By such movement, the wiping is conducted.
FIG. 4 illustrates an example of the ink cartridge 45 containing ink to be supplied through an ink supplying member such as a tube (not shown). The ink container portion 40, for example an ink bag, contains an ink to be supplied, and has a rubber plug 42 at the tip. By inserting a needle (not shown in the figure) into the plug 42, the ink in the ink container portion 40 becomes suppliable. An absorption member 44 absorbs waste ink.
The ink container portion preferably has a liquid-contacting face made of polyolefin, especially polyethylene in the present invention.
The ink-jet recording apparatus used in the present invention is not limited to the above-mentioned one which has separately a head and an ink cartridge. Integration thereof as shown in FIG. 5 may suitably be used.
In FIG. 5, a recording unit 70 houses an ink container portion such as an ink absorption member, and the ink in the ink absorption member is ejected from a head 71 having a plurality of orifices. The material for the ink absorption member is preferably polyurethane in the present invention.
Air-communication opening 72 is provided to communicate interior of the cartridge with the open air.
The recording unit 70 may be used in place of the recording head shown in FIG. 3, and is readily mountable to and demountable from the carriage 66.
The present invention is described in more detail referring to examples and comparative examples. The unit "%" in the description is based on weight unless otherwise mentioned. The value of "pH" in the description is a hydrogen ion concentration of a finished recording liquid.
EXAMPLE 1
______________________________________Exemplified dye No. 1 4%Diethylene glycol 30%Deionized water 66%pH 6.5______________________________________
EXAMPLE 2
______________________________________Exemplified dye No. 2 3%Diethylene glycol 20%Polyethylene glycol 10%(Average molecular weight: 300)Deionized water 67%pH 5.1______________________________________
EXAMPLE 3
______________________________________Exemplified dye No. 3 3%Diethylene glycol 15%N-methyl-2-pyrrolidone 15%Deionized water 67%pH 8.5______________________________________
EXAMPLE 4
______________________________________Exemplified dye No. 4 2%Triethylene glycol 28%Deionized water 70%pH 9.4______________________________________
EXAMPLE 5
______________________________________Exemplified dye No. 5 3%Diethylene glycol 20%Ethyl alcohol 5%Deionized water 72%pH 7.3______________________________________
EXAMPLE 6
______________________________________Exemplified dye No. 6 3%Diethylene glycol 20%Ethyl alcohol 5%Deionized water 72%pH 6.8______________________________________
EXAMPLE 7
______________________________________Exemplified dye No. 8 4%Diethylene glycol 15%N-methyl-2-pyrrolidone 15%Deionized water 66%pH 4.9______________________________________
EXAMPLE 8
______________________________________Exemplified dye No. 7 4%Diethylene glycol 30%Deionized water 66%pH 6.3______________________________________
The above-mentioned components were sufficiently mixed and dissolved in a vessel, respectively. The mixtures were filtered under pressure by use of a teflon filter having a pore diameter of 0.22 μm to prepare the inks of the present invention.
The inks above were respectively mounted on an ink-jet printer BJ-130A (made by Canon K. K., nozzle number: 48 nozzles), and solid printing was conducted in a size of 15 mm×30 mm on the recording mediums A, B, and C. Subsequently, the printed matters were left standing for 120 minutes in a dark chamber containing ozone at a concentration of 3±2 ppm for accelerating discoloration. The color differences ΔE*ab brought about by the test were measured (according to JIS S 8730). In every case, the ΔE*ab was not more than 10, giving less discoloration, which was satisfactory.
Recording medium A: Specified paper (coated paper) for ink jet printer (IO-730) made by Sharp Corporation;
Recording medium B: Specified paper (coated paper) for PIXEL PRO made by Canon K. K.);
Recording medium C: Specified paper (coated paper) for Paint Jet made by Hewlett Packard Co.
With the above-mentioned ink and printer, the ink was ejected in an amount corresponding to 1000 sheets of printing in A4 size (1500 letters per sheet), and thereafter printing of alphabets and numerals was conducted on the Recording medium B. As the results, the quality of the print was satisfactory without defect such as blurring and chipping of the alphabets or numerals.
For comparison, the components below were mixed as in the above Examples to prepare inks, and employed for solid printing on the Recording mediums A and B. The printed matter was tested in the aforementioned ozone-containing test chamber in the same manner as above. It was found that in every case, the value of ΔE*ab was 20 or more, giving high degree of discoloration.
COMPARATIVE EXAMPLE 1
______________________________________C.I. Food Black 2 4% ##STR6##Diethylene glycol 30%Deionized water 66%______________________________________
COMPARATIVE EXAMPLE 2
______________________________________C.I. Direct Black 51 3% ##STR7##Diethylene glycol 20%Polethylene glycol 10%(Average molecular weight: 300)Deionized water 67%______________________________________
COMPARATIVE EXAMPLE 3
______________________________________C.I. Direct Black 91 3% ##STR8##Diethylene glycol 15%N-methyl-2-pyrrolidone 15%Deionized water 67%______________________________________
The use of the dye represented by the general formula (I) gives an ink which has the properties required for printed matters on ordinary paper and also is capable of giving a less discoloring image on coated paper. Further it gives an image of high image quality with high resolution and less discoloration, and having satisfactory fastness properties.
The ink of the present invention exhibits sufficiently the aforementioned characteristics at the neutral range of pH 4 to 10, which is satisfactory in view of safety because of no need of addition of strongly alkaline substance such as described in Japanese Patent Application Laid-Open No. 56-57862.
Furthermore, the ink of the present invention, even when applied to ink-jet recording method which ejects ink by action of thermal energy, can be used stably for long time without forming an adhering matter on the heater, and does not change its physical properties nor forming no solid deposit during storage.
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An ink including a recording agent and a liquid medium for dissolution or dispersion thereof, the recording agent being a compound represented by the general formula ##STR1## wherein R 1 and R 2 are respectively a radical selected from the group of lower alkyl, lower alkoxy, --NHCOCH 3 , --COOM, and --SO 3 M; R 3 , R 4 , and R 5 are respectively a radical selected from the group of hydrogen, hydroxyl, lower alkyl, lower alkoxy, amino, --SO 3 M, and --COOM; A is ##STR2## R 6 and R 7 are respectively a radical selected from the group of hydrogen, hydroxyl, and lower alkoxy; m is 1 or 2; n is 0 or 1; and M is alkali metal or ammonium.
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RELATED APPLICATIONS
The present application is a continuation in part of U.S. patent application Ser. No. 11/385,807, filed Mar. 22, 2006 now U.S. Pat. No. 7,380,737 and titled “ELECTRIC SEASONING MILL”, which is incorporated herein by reference.
BACKGROUND
The present invention relates to an electric seasoning mill capable of containing and dispensing two kinds of seasonings.
In order to preserve the original taste of various kinds of seasonings, seasonings are usually stored in larger particle sizes, and ground and directly dispensed with seasoning grinders when people want to use them.
A currently existing manual seasoning mill structure includes a hollow main body, a rotary operating member connected to an upper end of the hollow main body, a transmission shaft held in the main body and turnable together with the rotary operating member, an inner toothed part joined to a lower end of the transmission shaft, and an outer toothed part positioned around the inner toothed part and secured to an inner side of the main body. Seasonings are contained in the hollow main body. Thus, the inner toothed part will turn relative to the outer toothed part to grind seasonings together with the outer toothed part when the operating member is rotated.
However, it requires unwarranted time and labor to use the manual seasoning mill, and it is difficult for those people who can't use their hands very dexterously to operate such seasoning mills smoothly. Further, this prior art seasoning mill can contain only one kind of seasoning or one kind of seasoning combination instead of two.
Various electric seasoning grinders are available such as were disclosed in Patent CH675961A5, DE20215609U1, U.S. Pat. No. 4,685,625, and U.S. Pat. No. 3,734,417. The electric grinders include a motor, a grinding mechanism, a transmission shaft connected to both the motor and the grinding mechanism, and a switch for turning on/off the motor. However, these grinders aren't very practical because they can contain only one kind of seasoning or one kind of seasoning combination.
Although there are several different dual-use seasoning grinders available to consumers which have two separate rooms for containing two kinds of seasonings, and although these can grind the two kinds of seasonings separately (such as were disclosed in Patents/applications US2003/052207 A1, EP0876787A, and GB256378A,) they are hand-operated and not convenient to use.
SUMMARY
An electric seasoning mill according to one embodiment disclosed herein includes a main body, a motor, a power supply unit for powering the motor, first and second milling assemblies, and first and second transmission shafts. The main body has first and second opposed ends, a first holding room adjacent the first end, and a second holding room adjacent the second end. The motor is housed in the main body between the first and second ends. The motor has a first output shaft extending toward the main body first end and a second output shaft extending toward the main body second end. The first and second output shafts are rotatable in concert in a first direction relative to the main body and rotatable in concert in a second direction relative to the main body. The first and second milling assemblies are respectively adjacent the first and second holding rooms; each milling assembly has a stationary portion and a rotatable portion. The first transmission shaft operatively couples the first output shaft and the first milling assembly rotatable portion; the second transmission shaft operatively couples the second output shaft and the second milling assembly rotatable portion. Means are included for automatically actuating the motor to rotate the first and second output shafts in the first direction upon a tilting of the main body so that the first holding room is below the second holding room, and for automatically actuating the motor to rotate the first and second output shafts in the second direction upon a tilting of the main body so that the second holding room is below the first holding room.
An electric seasoning mill according to another embodiment disclosed herein includes a main body, a motor, a power supply unit for powering the motor, first and second milling assemblies, and first and second transmission shafts. The main body has first and second opposed ends, a first holding room adjacent the first end, and a second holding room adjacent the second end. The motor is housed in the main body between the first and second ends. The motor has a first output shaft extending toward the main body first end and a second output shaft extending toward the main body second end. The first and second output shafts are rotatable relative to the main body generally simultaneously; both the first and second output shafts are rotatable in first and second directions relative to the main body. The first and second milling assemblies are respectively adjacent the first and second holding rooms; each milling assembly has a stationary portion and a rotatable portion. The first transmission shaft operatively couples the first output shaft and the first milling assembly rotatable portion; the second transmission shaft operatively couples the second output shaft and the second milling assembly rotatable portion. Means are included for automatically actuating the motor to rotate the first output shaft in the first direction upon a tilting of the main body so that the first holding room is below the second holding room, and for automatically actuating the motor to rotate the first output shaft in the second direction upon a tilting of the main body so that the second holding room is below the first holding room.
An electric seasoning mill according to another embodiment disclosed herein includes a main body, a motor, a power supply unit for powering the motor, first and second milling assemblies, a switch, and first and second transmission shafts. The main body has first and second opposed ends, a first holding room adjacent the first end, and a second holding room adjacent the second end. The motor is housed in the main body between the first and second ends. The motor has a first output shaft extending toward the main body first end and a second output shaft extending toward the main body second end. The first and second output shafts are rotatable relative to the main body generally simultaneously; both the first and second output shafts are rotatable in first and second directions relative to the main body. The first and second milling assemblies are respectively adjacent the first and second holding rooms; each milling assembly has a stationary portion and a rotatable portion. The first transmission shaft operatively couples the first output shaft and the first milling assembly rotatable portion; the second transmission shaft operatively couples the second output shaft and the second milling assembly rotatable portion. The switch has a channel containing at least one movable member. The channel has a first raised region, a second raised region, and a generally flat region connecting the first and second regions. First and second contact points are within the first raised region and biased toward a non-contacting configuration; third and fourth contact points are within the second raised region and biased toward a non-contacting configuration. The at least one movable member is configured to compel contact between the first and second contact points when the main body is tilted so that the first holding room is below the second holding room, and to compel contact between the third and fourth contact points when the main body is tilted so that the second holding room is below the first holding room. Contact between the first and second contact points completes a first circuit and causes the motor to rotate the first output shaft in the first direction; contact between the third and fourth contact points completes a second circuit and causes the motor to rotate the first output shaft in the second direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a seasoning mill according to an embodiment.
FIG. 2 is a perspective sectional view of the seasoning mill of FIG. 1 .
FIG. 3 is a front sectional view of the seasoning mill of FIG. 1 .
FIG. 4 is a top sectional view of the seasoning mill of FIG. 1 .
FIG. 5 is a side sectional view of the seasoning mill of FIG. 1 .
FIG. 6 is a detailed side sectional view of the seasoning mill of FIG. 1 .
FIG. 7 is a sectional view of a control switch appropriate for use in the seasoning mill of FIG. 1 .
FIG. 8 is a simplified circuit diagram appropriate for use in the seasoning mill of FIG. 1 .
FIG. 9 is a top view of a locking knob appropriate for use in the seasoning mill of FIG. 1 .
FIG. 10 is a front sectional view of another control switch appropriate for use in the seasoning mill of FIG. 1 , the control switch being in a generally horizontal configuration.
FIG. 11 is a front sectional view of the control switch of FIG. 10 , the control switch being in a generally vertical configuration.
FIG. 12 is a partial perspective view of a switch appropriate for use in the seasoning mill of FIG. 1 , the switch being shown in one configuration.
FIG. 13 is a partial perspective view of the switch of FIG. 12 , the switch being shown in another configuration.
DETAILED DESCRIPTION
Referring to FIGS. 1 to 9 , an electric seasoning mill 100 according to an embodiment includes a main body 1 , a motor 2 , a power supply unit 3 , a control switch 4 , two transmission shafts 5 , and first and second milling assemblies 6 .
The main body 1 has a holding room 11 in each of two ends thereof for containing seasonings; further, the main body 1 has a connecting section 12 between the holding rooms 11 , and a longitudinal guiding rail 13 therein.
The motor 2 is held in the connecting section 12 of the main body 1 ; the motor 2 has first and second output shafts 21 and 21 ′ at two ends thereof; when the motor 2 is activated, the first and the second output shafts 21 and 21 ′ will always rotate in a same direction, and rotational direction of the output shafts 21 and 21 ′ can be changed. In other words, the output shafts 21 and 21 ′ can rotate in a forward direction and they can rotate in a reverse direction. The output shafts 21 and 21 ′ are each connected to a reduction gear set 22 , and the reduction gear sets 22 are each connected to an one-way ratchet 23 at an output parts thereof.
The power supply unit 3 is held in the connecting section 12 of the main body 1 for supplying power to the motor 2 .
The control switch 4 is fitted to the connecting section 12 of the main body 1 for controlling supply of power from the power supply unit 3 to the motor 2 as well as for changing the rotational direction of the output shafts 21 and 21 ′ of the motor 2 ; the control switch 4 includes a button 41 , a locking knob 42 , a sliding block 43 , first and second electricity conducting plates 44 and 44 ′, and first, second, third, and fourth acting plates 45 , 46 , 47 , and 48 ( FIG. 7 ). As best shown in FIG. 9 , the button 41 has first and second pressing portions 411 at two ends thereof, which protrudes outside through a wall of the connecting section 12 of the main body 1 . The locking knob 42 has two wing portions 421 , and it is positioned between the two pressing portions 411 of the button 41 , and can be turned so as to be perpendicular to both the pressing portions 411 for locking the button 41 , thus preventing the button 41 from being depressed; the button 41 will unlock when the locking knob 42 is parallel to both the pressing portions 411 of the button 41 . The sliding block 43 is positioned next to an inner side of the button 41 , and fitted on the guiding rail 13 such that the sliding block 43 will slide along the guiding rail 13 when the main body 1 is held with one end thereof being right above the other ( FIGS. 4 and 6 ).
As shown in FIGS. 7 and 8 , the first electricity conducting plate 44 has a contact point (a) 441 , a contact point (b) 442 , and a contact point (c) 443 , while the second electricity conducting plate 44 ′ has a contact point (a) 441 ′, a contact point (b) 442 ′, and a contact point (c) 443 ′. The contact point (b) 442 is connected to a negative pole of the power supply unit 3 while the contact point (b) 442 ′ is connected to a positive pole of the power supply unit 3 ; the first acting plate 45 is constantly connected to both the motor 2 and the fourth acting plate 48 , and the second acting plate 46 is constantly connected to both the motor 2 and the third acting plate 47 . The wires connecting both the acting plates 45 and 48 cross, and are off the wires connecting both the acting plates 46 and 47 . The first acting plate 45 is off and movable to touch the contact point (a) 441 of the first electricity conducting plate 44 , the second acting plate 46 is off and movable to touch the contact point (a) 441 ′ of the second electricity conducting plate 44 ′, the third acting plate 47 is off and movable to touch the contact point (c) 443 , and the fourth acting plate 48 is off and movable to touch the contact point (c) 443 ′. Under a normal condition, neither of the pressing portions 411 of the button 41 is depressed.
When the sliding block 43 is near to the inner side of the first pressing portion 411 of the button 41 , and the first pressing portion 411 is pressed, the sliding block 43 will press the acting plates 45 and 46 to make the acting plates 45 and 46 get into contact with the contact points (a) 441 and 441 ′ respectively, and the motor 2 will be activated to rotate in a first direction; the motor 2 won't be activated when the second pressing portion 411 of the button 41 is pressed.
On the other hand, when the sliding block 43 is near to the inner side of the second pressing portion 411 of the button 41 , and the second pressing portion 411 is pressed, the sliding block 43 will press the acting plates 47 and 48 to make the acting plates 47 and 48 get into contact with the contact points (c) 443 and 443 ′ respectively, and the motor 2 will be activated to rotate in a reverse direction opposite to the first one.
The first and the second milling assemblies 6 are held in respective ones of the holding rooms 11 of the main body 1 , positioned near to the openings of the holding rooms 11 . Each of the milling assemblies 6 includes an inner toothed part 61 , and an outer toothed part 62 , which is positioned around the inner toothed part 61 and secured to the main body 1 , near to the opening of the corresponding holding room 11 .
The transmission shafts 5 are each held in a respective one of the holding rooms 11 , and connected to a respective one of the one-way ratchets 23 at one end such that it will be turned with the one-way ratchet 23 only when the one-way ratchet 23 is turned in a certain predetermined direction; further, the transmission shafts 5 are each connected to a respective one of the inner toothed parts 61 of the milling assemblies 6 at the other end.
Therefore, when the seasoning mill 100 is held with the first output shaft 21 and the corresponding first milling assembly 6 being right under the second output shaft 21 ′ and the second output shaft's corresponding second milling assembly 6 so as to allow the sliding block 43 to slide down along the guiding rail 13 owing to gravity, and when a currently lower one of the pressing portions 411 of the button 41 is pressed, the acting plates 45 and 46 will get into contact with the contact points (a) 441 and 441 ′ respectively, and the motor 2 will start rotating in the first direction for allowing the one-way ratchet 23 connected to the first output shaft 21 to rotate and cause the corresponding transmission shaft 5 to rotate together with it. Thus, the inner toothed part 61 of the first milling assembly 6 , which is currently in the lower position, will rotate to grind seasonings together with the outer toothed part 62 . On the other hand, the one-way ratchet 23 connected to the second output shaft 21 ′ (currently in the upper position) will rotate, but it won't cause the corresponding transmission shaft 5 to rotate together with it; thus, the second milling assembly 6 (currently in the upper position) won't work. The sliding block 43 will be off the acting plates 45 and 46 , and the motor 2 will stop rotating when the user stops pressing the button 41 . And, because the sliding block 43 has slid down along the guiding rail 13 to be apart from the second pressing portion 411 of the button 41 , the motor 2 won't be activated when the mill is held in the above-mentioned position, and the second pressing portion 411 is pressed.
When the seasoning mill is held in an inverted position, in which position the second output shaft 21 ′ and the corresponding second milling assembly 6 are right under the first output shaft 21 so as to allow the sliding block 43 to slide down along the guiding rail 13 owing to gravity, and when a currently lower one of the pressing portions 411 of the button 41 is pressed, the acting plates 47 and 48 will get into contact with the contact points (c) 443 and 443 ′ respectively, and the motor 2 will start rotating in the reverse direction opposite to the first one for allowing the one-way ratchet 23 connected to the second output shaft 21 ′ to rotate and cause the corresponding transmission shaft 5 to rotate together with it. Thus, the inner toothed part 61 of the second milling assembly 6 (currently in the lower position) will rotate to grind seasonings together with the outer toothed part 62 . On the other hand, the one-way ratchet 23 connected to the first output shaft 21 (currently in the upper position) will rotate, but it can't cause the corresponding transmission shaft 5 to rotate together with it; thus, the first milling assembly 6 (currently in the upper position) won't work. The sliding block 43 will be off the acting plates 47 and 48 , and the motor 2 will stop rotating when the user stops pressing the button 41 . And, the motor 2 won't be activated when the first pressing portion 411 of the button 41 is pressed with the mill being held in the above-mentioned position.
Furthermore, when the locking knob 42 is turned to such a position that the wing portions 421 are perpendicular to the pressing portions 411 of the button 41 , and right on an outer side of the main body 1 , as shown in FIG. 9 , the locking knob 42 will prevent the button 41 from being depressed, thus preventing the motor 2 from being accidentally activated.
From the above description, it can be easily seen that the electric seasoning mill 100 has two milling assemblies 6 and two holding rooms 11 for containing two kinds of seasonings or two kinds of seasoning combinations, and only a currently lower one of the milling assemblies 6 will work to grind seasonings contained in the currently lower holding room 11 no matter in which one of the upright and the inverted positions the seasoning mill 100 is held. Therefore, the seasoning mill 100 is relatively convenient to use. Furthermore, the electric seasoning mill 100 can be prevented from being accidentally activated by means of turning the locking knob 42 to such a position as to lock the button 41 of the control switch 4 ; therefore the seasoning mill 100 is relatively safe to use.
FIGS. 10 and 11 show an alternate switch 4 ′ that may be used in the seasoning mill 100 instead of (or in addition to) the switch 4 described above. The alternate switch 4 ′ includes a channel 401 ′ containing at least one movable member 402 ′. While five spherical balls are shown as movable members 402 ′, more or fewer balls may be used, and/or non-spherical members may be used. The channel 401 ′ includes a first raised region 401 a ′, a second raised region 401 b ′, and a generally flat region 401 c ′ connecting the first and second regions 401 a ′, 401 b ′. The flat region 401 c ′ may be generally parallel to the transmission shafts 5 , for example. First and second contact points 402 ′, 403 ′ are located within the first region 401 a ′, and third and fourth contact points 404 ′, 405 ′ are located within the second region 401 b′.
When the switch 4 ′ is at a horizontal configuration as shown in FIG. 10 (e.g., when neither of the milling assemblies 6 is below the other milling assembly 6 ,) the movable member(s) 402 ′ are located in the flat region 401 c ′ due to gravity. While the movable member(s) 402 ′ are located in the flat region 401 c ′, the first and second contact points 402 ′, 403 ′ do not contact each other, and the third and fourth contact points 404 ′, 405 ′ do not contact each other; the motor 2 remains inactivated, and neither milling assembly 6 rotates.
When the switch 4 ′ is at a vertical configuration as shown in FIG. 11 (e.g., when one of the milling assemblies 6 is below the other milling assembly 6 ,) the movable member(s) 402 ′ are located in the first raised region 401 a ′ or the second raised region 401 b ′ due to gravity. When the movable member(s) 402 ′ are located in the first or second raised region 401 a ′, 401 b ′, the movable member(s) 402 ′ force the first contact point 402 ′ to contact the second contact point 403 ′ or the third contact point 404 ′ to contact the fourth contact point 405 ′, respectively. As illustration, FIG. 11 shows the movable member(s) 402 ′ in the first raised region 401 a ′, causing the first contact point 402 ′ to contact the second contact point 403 ′.
Contact between the first and second contact points 402 ′, 403 ′ completes an electrical circuit and causes the motor 2 to rotate in one direction as described above. Contact between the third and fourth contact points 404 ′, 405 ′ completes another electrical circuit and causes the motor 2 to rotate in another direction as described above. As such, the motor 2 may be automatically actuated and a respective milling assembly 6 may be utilized simply by holding the main body 1 in a non-horizontal manner. It should be understood that the amount of angle between the first raised region 401 a ′ and the flat region 401 c ′ and between the second raised region 401 b ′ and the flat region 401 c ′ can be altered to affect the amount of tilt required to contact the respective contact point 402 ′, 404 ′ with the movable member(s) 402 ′.
FIGS. 12 and 13 show a switch 120 that may be used in addition to (or instead of) the switch 4 ′ described above in relation to FIGS. 10 and 11 or to the switch 4 described above. The switch 120 selectively completes an electrical circuit or at least a portion of an electrical circuit, allowing the motor 2 to rotate as described above. More particularly, when the electrical circuit incorporating the switch 120 is not completed ( FIG. 12 ), the motor 2 may not be actuated; when the electrical circuit incorporating the switch 120 is completed ( FIG. 13 ), the motor 2 may be actuated as long as any additional switch (e.g., the switch 4 ′ or the switch 4 ) is activated.
The switch 120 includes first and second contact members 121 , 122 and a driving member 123 . The first and second contact members 121 , 122 are biased so that the first and second contact members 121 , 122 are not typically in contact, as shown in FIG. 12 . The driving member 123 may selectively force the first contact member 121 to contact the second contact member 122 , as shown in FIG. 13 . When the first and second members 121 , 122 are not in contact, the electrical circuit or the portion of the electrical circuit is not completed. When the first and second members 121 , 122 are in contact, the electrical circuit or the portion of the electrical circuit is completed.
As shown in FIGS. 12 and 13 , the driving member 123 may have a coupling portion 124 that is seated in a groove 125 defined by the main body 1 . The groove 125 may extend completely around the main body 1 as shown, or the groove 125 may alternately extend around only a portion of the main body 1 . An outer wall 124 a of the coupling portion 124 may be accessed by a user to selectively move the driving member 123 as discussed above. While a specific driving member 123 has been shown and discussed, it should be understood that the driving member 123 may be configured differently to selectively force contact between the first and second contact members 121 , 122 and that such is contemplated herein.
Those skilled in the art appreciate that variations from the specified embodiments disclosed above are contemplated herein. The description should not be restricted to the above embodiments, but should be measured by the following claims.
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An electric seasoning mill includes a body having first and second holding rooms adjacent first and second ends. A motor is housed between the first and second ends. The motor has first and second output shafts extending toward the first and second ends; the first and second output shafts are rotatable in first and second directions. First and second milling assemblies are adjacent the first and second rooms; each milling assembly has stationary and rotatable portions. A first transmission shaft operatively couples the first output shaft and the first milling assembly rotatable portion; a second transmission shaft operatively couples the second output shaft and the second milling assembly rotatable portion. Means are included for automatically actuating the motor to rotate the first output shaft in the first and second directions upon tilting the main body in first and second manners.
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FIELD OF INVENTION
[0001] The present disclosure relates to oil systems, and, more specifically, to a sealing adapter for an oil system.
BACKGROUND
[0002] Fluids or gasses may pass into and out pressurized vessels in mechanical systems such as oil systems in a vehicle. Joints may connect components of the system and may be subject to leakage unless sealed. A variety of joint and seal types may be used, each having strengths and weaknesses. Metal C-seals may have been incorporated in flanges using multiple bolts to crush the C-seal. The bolts may result in uneven crimping of the seal depending on the order in which bolts are tightened down. Threaded connections may use an elastomeric 0 -ring seal. However, the elastomeric seal may not be suitable for use in high-temperature environments.
SUMMARY
[0003] An adapter and seal system may comprise a cylindrical body centered about an axis and a first thread disposed about an outer diameter of the cylindrical body. A protrusion on the cylindrical body may extend radially outward from the cylindrical body with a surface orthogonal to the axis partially defining the protrusion. A circular trench may be formed in the surface and may open in an axial direction towards the first thread. A metallic C-seal may be disposed in the circular trench.
[0004] In various embodiments, a wrenching feature may be disposed about an outer diameter of the protrusion. The C-seal may include an opening disposed on an inner diameter of the C-seal. A locking feature may be disposed on the protrusion. A second thread may be disposed about the outer diameter of the cylindrical body with the protrusion located between the first thread and the second thread. A cone seat may be disposed at an axial end of the cylindrical body. The adapter may be configured to distribute crushing load to the C-seal in an axial direction and/or to distribute crushing load evenly about the circumference of the C-seal. The adapter may also comprise an austenitic nickel-chromium-based alloy.
[0005] An oil system may comprise a first oil component and an adapter sealably coupled to the first oil component. The adapter may comprise a cylindrical body centered about an axis. A first thread may be disposed about an outer diameter of the cylindrical body. A protrusion on the cylindrical body may extend radially outward from the cylindrical body and be partially defined by a surface orthogonal to the axis. A circular trench may be formed in the surface and open in an axial direction towards the first thread. A metallic C-seal may be disposed in the circular trench and compressed between the adapter and the first oil component.
[0006] In various embodiments, the metallic C-seal may include an opening disposed on an inner diameter of the C-seal. A locking feature may be disposed on the protrusion. A second thread may also be disposed about the outer diameter of the cylindrical body with the protrusion located between the first thread and the second thread. A cone seat may be disposed at an axial end of the cylindrical body. The adapter may be configured to distribute crushing load to the C-seal in an axial direction. The adapter may also distribute crushing load evenly about the circumference of the C-seal. A wrenching feature may be disposed about an outer diameter of the protrusion.
[0007] A method of sealably coupling an adapter and an oil component may comprise the steps of rotating the adapter about an axis to threadedly engage adapter and a threaded female member of the oil component, and compressing a C-seal disposed in a groove of the adapter in response to the threadedly engaging the adapter, wherein the groove is formed in a surface of the adapter oriented in a plane orthogonal to the axis.
[0008] In various embodiments, the method may further include placing the C-seal in the groove with an opening disposed on the inner diameter of the C-seal. The step of compressing the C-seal may also comprise applying a compressive force uniformly about a circumference of the C-seal.
[0009] The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the figures, wherein like numerals denote like elements.
[0011] FIG. 1 illustrates a perspective view of a threaded adapter for use with a C-seal, in accordance with various embodiments;
[0012] FIG. 2 illustrates a cross section of a threaded adapter for use with a C-seal, in accordance with various embodiments;
[0013] FIG. 3A illustrates an annular C-seal with an opening on the inner diameter, in accordance with various embodiments;
[0014] FIG. 3B illustrates a cut away of an annular C-seal with an opening on the inner diameter, in accordance with various embodiments; and
[0015] FIG. 4 illustrates a cross section of a threaded adapter and C-seal installed in an oil system, in accordance with various embodiments.
DETAILED DESCRIPTION
[0016] The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the exemplary embodiments of the disclosure, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein. Thus, the detailed description herein is presented for purposes of illustration only and not limitation. The steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented.
[0017] Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. Surface shading lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials.
[0018] In various embodiments, metallic C-seals may provide improved sealing when the seal is crimped and/or bent uniformly. The adapter described herein may apply compressive force distributed uniformly about the circumference of a C-seal and thus crimp or bend the C-seal in a uniform manner. The adapter may also direct the compressive force in a direction normal to a sealing surface to increase stability and uniformity during compression of the C-seal. Thus, the metallic adapter and C-seal system may provide sealing in high-temperature application such as heated oil systems.
[0019] With reference to FIGS. 1 and 2 , an adapter 100 for use with a C-seal is shown, in accordance with various embodiments. Adapter 100 may comprise a cylindrical body 102 having an axisymmetric or rotationally symmetric geometry centered about axis A. Cylindrical body 102 may have various portions with differing diameters. Male mating surface 104 of cylindrical body 102 may comprise thread 106 disposed about an outer diameter of cylindrical body 102 . A cone seat 108 may be disposed at a radial end of cylindrical body 102 . The cone seat may be oriented at an angle relative to cylindrical body ranging from 30 to 50 degrees. For example, cone seat may have an angle of 37 degrees relative to cylindrical body 102 . Male mating surface 104 and cone seat 108 may provide an interface to connect adapter 100 to another system component.
[0020] In various embodiments, a wrenching feature 110 may protrude from cylindrical body 102 in a radial direction. Wrenching feature 110 may comprise a polygonal shape to engage a wrench during installation, maintenance, or removal. The configuration and size of wrenching feature 110 may vary. For example, the wrenching feature may be configured in 6-point hexagonal configuration or 12-point configuration. A locking feature may be located on adapter 100 . For example, safety cable holes 112 may be defined in a protrusion of wrenching feature 110 from cylindrical body 102 .
[0021] In various embodiments, male mating surface 116 may be disposed at an opposite end of adapter 100 from cone seat 108 in an axial direction. Male mating surface 116 of cylindrical body 102 may include threads 118 disposed about an outer diameter of cylindrical body 102 . A cylindrical passage 120 may be defined by an inner diameter of cylindrical body 102 .
[0022] In various embodiments, surface 122 may partially define wrenching feature 110 protruding from cylindrical body 102 . Surface 122 may be a flat surface oriented coplanar with a radial plane orthogonal to axis A. Surface 122 may define an opening 136 of groove 114 with opening 136 being coplanar with surface 122 . Opening 136 of groove 114 may face in an axial direction towards thread 118 . Groove 114 may have a distal wall 132 and proximal wall 130 . Distal wall 132 and proximal wall 130 may be axisymmetric about axis A and parallel to one another when viewed in cross section as illustrated in FIG. 2 . Groove 114 may also have a bottom surface 134 spanning between distal wall 132 and proximal wall 130 to define groove 114 . Groove 114 may have a substantially uniform depth about the circumference of groove 114 .
[0023] In various embodiments, adapter 100 may be made from metals or metal alloys including steel, titanium, nickel, aluminum, or other suitably rigid materials. For example, adapter 100 may be made from an austenitic nickel-chromium-based alloy such as that sold under the trademark Inconel®, which is available from Special Metals Corporation of New Hartford, N.Y., USA. Groove 114 of adapter 100 may be made by turning using a lathe to achieve the parallelism and flatness of the various features of adapter 100 described herein.
[0024] With reference to FIGS. 3A and 3B , a C-seal 200 is shown, in accordance with various embodiments. C-seal 200 may comprise an annular shape with a convex outer surface 202 and a concave inner surface 206 . C-seal 200 may also comprise a C-shaped cross section with an opening into cavity 204 located on an inner diameter or an outer diameter of C-seal 200 . Cavity 204 may be defined by concave inner surface 206 of C-seal 200 . With brief reference to FIG. 2 , C-seal 200 may be configured to fit into groove 114 to provide sealing against adapter 100 . C-seal 200 may protrude slightly from groove 114 in response to resting in groove 114 against bottom surface 134 absent a compressive force.
[0025] In various embodiments, C-seal 200 may be made from metals or metal alloys including steel, titanium, nickel, aluminum, silver, or other suitably rigid materials. For example, C-seal 200 may be made from an austenitic nickel-chromium-based alloy such as that sold under the trademark Inconel®, which is available from Special Metals Corporation of New Hartford, N.Y., USA. The material selected for C-seal 200 may be chosen to provide favorable corrosion characteristics when located in groove 114 of adapter 100 during service.
[0026] With reference to FIG. 4 , seal system 300 is shown with adapter 100 and C-seal 200 installed in oil system, in accordance with various embodiments. Component 302 may be a tubular component or conduit configured to transport a fluid or gas. Component 302 may receive cone seat 108 with a female threaded member 304 disposed around the joint between component 302 and adapter 100 . Female threaded member 304 may have a threaded inner diameter to threadedly engage thread 106 of adapter 100 . Female threaded member 304 may also retain a seal 306 between an inner diameter of female threaded member 304 and an outer diameter of component 302 . Adapter 100 may sealably connect to component 302 to limit leakage of pressurized fluid or gas along the joint between adapter 100 and component 302 .
[0027] In various embodiments, adapter 100 may also sealably connect with component 312 . Component 312 may also be a tubular component or conduit configured to transport a fluid or gas. Thread 118 of adapter 100 may engage female mating surface 308 of component 312 . Thread 118 may also urge surface 122 of adapter 100 against surface 310 of component 312 in response to rotation about the axis caused by, for example, rotation of wrenching feature 110 , such as rotation of wrenching feature 110 in response to rotation by a wrench or other tool. Surface 310 and surface 122 may lie flat against one another. C-seal 200 may be disposed within groove 314 and thus located between adapter 100 and surface 310 of component 312 . As adapter 100 is threaded into component 312 , surface 310 may contact C-seal 200 and provide a compressive force as surface 310 and surface 122 come together.
[0028] In various embodiments and with reference to FIGS. 2 and 4 , adapter 100 may be configured to distribute a crushing load to the C-seal in an axial direction as thread 118 urges surface 122 in the direction of surface 310 in response to rotation of adapter 100 . The flat contour of surface 310 that is also normal to the relative motion between adapter 100 and component 312 may direct the crushing load and/or compressive force in a normal direction (i.e., an axial direction relative to axis A as adapter 100 is rotating). The adapter may also distribute crushing load evenly about the circumference of the C-seal as thread 118 urges surface 122 in the direction of surface 310 in response to rotation of adapter 100 . The compressive force exerted on C-seal 200 as surface 122 and surface 310 are pressed together may crimp and bend C-seal 200 in a substantially uniform manner to provide sealing between component 312 and adapter 100 in high-temperature applications.
[0029] Benefits and other advantages have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, and any elements that may cause any benefit or advantage to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.
[0030] Systems, methods and apparatus are provided herein. In the detailed description herein, references to “various embodiments”, “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
[0031] Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f), unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
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An adapter and seal system is provided. The system may comprise a cylindrical body centered about an axis and a first thread disposed about an outer diameter of the cylindrical body. A protrusion on the cylindrical body may extend radially outward from the cylindrical body with a surface orthogonal to the axis partially defining the protrusion. A circular trench may be formed in the surface and may open in an axial direction towards the first thread. A metallic C-seal may be disposed in the circular trench.
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BACKGROUND OF THE INVENTION
The present invention relates to a new and improved method of, and apparatus for, processing waste paper in order to obtain a stock suspension for the fabrication of new paper and cardboard, wherein the waste paper is defiberized in water within a stock pulper or slusher.
With heretofore known installations of this type, such as disclosed for instance in Austrian Patent No. 346,170, the stock pulper has arranged thereafter a secondary pulper or fiberizer. The good stock effluxing out of the secondary pulper is subjected to a complicated post-treatment before it reaches the paper-making machine. On the other hand, the overflow of the secondary pulper, containing the contaminants, is returned back into the stock pulper or slusher. The equipment needed for this purpose is relatively complicated and also requires a great deal of energy, since the total quantity of the obtained stock suspension must be processed during the post-treatment and also the return flow into the stock pulper or slusher means that this slusher is additionally loaded.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind it is a primary object of the present invention to provide a new and improved method of, and apparatus for, processing waste paper which is not associated with the aforementioned drawbacks and limitations of the prior art constructions.
Another and more specific object of the present invention aims at providing a new and improved method of, and apparatus for, processing waste paper by means of which it is possible to accomplish the waste paper processing operation in an appreciably simpler manner and with the use of much simpler means, and additionally there is required a lesser expenditure in energy.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the method of the present development is manifested by the features that there are screened from the stock suspension following the stock slusher or pulper, by means of a sieve or screen device having suitable perforations or holes, all fibres which are directly suitable for paper fabrication, whereas the contaminants which do not pass through the screen and the overflow containing incompletely defiberized paper parts is subjected to a mechanical comminution action, whereafter by means of a subsequently connected sieve or screen device having suitable perforations or holes there is again screened all fibres which are directly suitable for the paper fabrication.
With the mode of operation according to the inventive method an extremely large proportion of the fibrous material in the form of already usable stock suspension is eliminated from the processing operation, so that the post-treatment can be limited to an appreciably smaller proportion of the material which is to be processed. The smaller quantity of material thereafter can be intensively post-treated with reduced energy consumption, and likewise the obtained good stock can be immediately infed to the papermaking machine.
Preferably, also the overflow of the second sieve or screen device can be subjected to a mechanical comminution action, and thereafter can be screened in a third screen or sieve device. As a result there is further increased the yield in good stock from the infed waste paper.
Moreover, the overflowing stock suspension of the second screen device, prior to being delivered to the third screen device, can be subjected to shearing loads. Due to the shearing loads, for instance in a conventional despeckling device, there are defiberized selective pieces of waste paper, whereas plastic foils remain essentially uncomminuted. This facilitates the subsequent separation of the plastic foils from the paper fibres by screening.
The apparatus or installation of the present invention, suitable for performing the inventive method, comprises a stock pulper or slusher and a secondary pulper or fiberizer arranged after the stock pulper. The fiberizer contains a housing in which there is located a sieve or screen and a motor-driven rotor provided with arms. The arms move along the screen. Merging with the sieve or screen is an outlet for good stock which passes through the screen, and the housing contains at least one outlet for material overflow effluxing out of the housing.
According to the inventive installation the sieve of the secondary pulper or fiberizer contains perforations which are suitable for eliminating fibres which can be directly employed for paper fabrication. At the outlet for the good stock of the secondary pulper or fiberizer there is connected the vat or tub of the papermaking machine. At the outlet for the material overflow from the first secondary pulper or fiberizer there is connected a second secondary pulper or fiberizer which likewise has a sieve or screen containing perforations or holes which serve for screening all fibres which can be directly used for paper fabrication. The outlet of the second fiberizer for good stock passing through the screen likewise is connected with the vat of the papermaking machine.
With this construction of installation the basically known stock pulper or slusher has imparted thereto a new action in that it serves for screening the fibre material from the stock suspension and already used following the stock slusher or pulper. The secondary pulper or fiberizer enables, in a most simple manner, combining the screening and mechanical comminution action in a single housing and in a single machine. As to the known secondary pulpers or fiberizers the secondary pulper of the instant installation differs therefrom due to the perforations or holes of the screen or sieve which are appreciably smaller than those of the known stock pulpers. Those are therefore not capable of screening the fibres which are directly suitable for paper fabrication.
It should however be expressly understood that the screening and comminution in the secondary stock pulpers or fiberizers only constitutes one particular advantageous measure, and that there can be additionally used, for instance, separate thick stock sorting devices containing special grinding devices.
The sieve or screen of the first secondary pulper preferably can be provided, for the stated purpose, with perforations having a hole diameter in a range of two to three millimeters.
Preferably, the screen of the second secondary pulper or fiberizer likewise can contain perforations having a hole diameter in a range of two to three millimeters. These are holes or openings which are suitable for eliminating the employed good stock, whereas fibre lumps and contaminants no longer can pass through the screen or sieve and remain in the circulation system of the related stock pulper.
At the oulet line for lighter material overflow of the second secondary pulper or fiberizer there can be connected a dynamic jarrer or vibrator. This dynamic jarrer forms a third sieve or screen device which enables further obtaining useful stock fibres, whereas by means of the screen of the dynamic jarrer there are finally separated-out the parts which have not passed therethrough.
The line or conduit leading from the second secondary pulper or fiberizer to the dynamic jarrer can be equipped with a despeckling device which exerts shear loads. This despeckling device enables carrying out the aforementioned selective comminution of paper pieces, whereas plastic foils essentially are not comminuted, so that they can be eliminated with the aid of the sieve or screen of the dynamic jarrer or vibrator.
For this purpose there can be provided a vat in the outlet line or conduit for the lighter overflow of the second stock pulper or fiberizer, and the despeckling device is connected in a circulation flow system of the vat. This arrangement enables separating the throughflow quantity of the despeckling device from the quantity flowing into the outlet line. Hence, the despeckling device or equivalent structure always has available to it optimum working conditions.
In particularly favourable cases the throughflow container of the dynamic jarrer or vibrator likewise can be connected with the vat of the papermaking machine. Otherwise there is possible a return of the liquid containing the paper fibres and effluxing from the throughflow container into a suitable part of the installation.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein the single FIGURE schematically illustrates an exemplarly embodiment of installation for processing waste paper and constructed according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawing, the installation for processing waste paper and working according to the teachings of the method of this development, shown by way of example and not limitation, will be seen to contain a stock pulper or slusher 1 constructed in conventional manner and having a housing 2 and a rotor 3 arranged for rotation therein. The rotor 3 is driven by a suitable electric drive motor 4. Beneath the rotor 3 there is located an outlet housing or compartment 5 which is separated by a sieve or screen 6 from the remaining chamber 1' of the housing 2. At the outlet housing 5 there is connected an outlet line or conduit 7 containing a pump 8 which leads to a secondary pulper or fiberizer 10.
The secondary pulper or fiberizer 10 which can be constructed, for instance, in the manner disclosed in U.S. Pat. No. 3,942,728, granted Mar. 9, 1976, U.S. Pat. No. 4,135,671, granted Jan. 23, 1979 or Austrian Patent No. 346,170, granted Oct. 25, 1978, contains a housing 11 within which there is located a rotor 12 whose arms 13 are movable along a sieve or screen 14 separating the internal chamber or compartment 11' of the housing 11 from an outlet housing or compartment 15. When the rotor 12 is operated it is driven by a suitable electric motor 16. Leading from the outlet housing 15 is an outlet line or conduit 17 to a vat or tub 18 for good stock, which for instance, can be constituted by the vat or chest of a not particularly illustrated papermaking machine.
The secondary pulper or fiberizer 10 has two outlet lines 20, 21, and specifically, the line 20 which extends out of its axial region, and the line or conduit 21 which extends out of its circumferential or external region. The outlet line 20 serves for the removal of stock suspension containing lighter contaminants or rejects, while the line or conduit 21 serves for withdrawing stock suspension containing heavier rejects or contaminants.
Both of the outlet lines 20 and 21 lead to an intermediate vat or chest 22 from which extends a line or conduit 23, equipped with a pump 24, this conduit 23 leading to a hydrocyclone 25. Extending out of the hydrocyclone 25 is a line or conduit 26 to a second secondary pulper or fiberizer 30 which can be constructed in the same manner as the first secondary pulper or fiberizer 10. Thus, as a matter of convenience the components or parts thereof have been designated by generally the same reference characters as the analogous parts or components of the fiberizer 10.
Leading from the outlet housing 15 of the second secondary pulper or fiberizer 30 is a line or conduit 31 to the good stock vat 18. An outlet line or conduit 32 which extends out of the central region of the housing 11 of the fiberizer 30 leads to an intermediate vat 33 or equivalent structure. An outlet line or conduit 34 leading from the circumference of the housing 11 of the secondary pulper or fiberizer 30 conveys heavy contaminants or rejects which should be eliminated from the installation and deposited.
Leading from the intermediate vat 33 is a line or conduit 35 which extends to a dynamic jarrer or vibrator 36 which contains a vibrating screen 37 and a throughpass container or vat 38. Leading outwardly from the throughpass container 38 is an outlet or outfeed line 40 which has two branches 41, 42, and specifically, branch 41 which leads to the good stock vat 18 and a branch 42 which leads back into the installation and at that location can be connected at a suitable point of the installation.
During operation of the equipment bales of waste paper are inserted into the stock slusher or pulper 1, and at the same time the water W needed for paper processing purposes, while possibly adding thereto suitable chemicals, is infed to the stock slusher or pulper 1. Eliminated heavy constituents can be removed from the stock slusher 1 by an outlet line 2', which for instance contains a conventional sluice.
The obtained stock suspension is removed from the stock slusher or pulper 1 through the line or conduit 7 and infed into the secondary pulper or fiberizer 10 where it is further processed. The fiberizer 10, which operates with a stock density of 3 percent to 5 percent, can have removed therefrom by the action of the sieve or screen 14 having holes or perforations in the order of 2 to 3 millimeters diameter, already approximately 60 to 80 percent of the stock suspension and such can be infed by means of the line or conduit 17 to the good stock vat 18. The relatively fine holes or perforations of the screen 14 ensure that only completely defiberized stock fibres can reach the good stock container 18, which therefore are immediately useful, without further processing, for fabricating paper or cardboard or the like.
By means of the lines or conduits 20 and 21 the stock or material which has overflown and not passed through the screen 14 arrives at the intermediate vat 22 and from that location is delivered into the hydrocyclone 25 where there are eliminated possibly remaining heavy constituents or rejects. In the second secondary pulper or fiberizer 30 there is completed the defiberizing and screening action, and the obtained good stock likewise is screened by the sieve or screen 14 having a perforation or hole size of 2 to 3 millimeters and is conveyed by the line or conduit 31 into the good stock vat 18.
Possibly remaining heavy constituents or rejects in the secondary pulper or fiberizer 30 are eliminated from the installation through the line or conduit 34. Stock suspension containing rejects and which has not passed through the screen 14 arrives by means of the outlet line 32 at the second intermediate vat 33. From this vat 33 it is possible to therefore place onto the vibrating screen 37 the stock suspension which can contain foil pieces formed of plastic and possible residual materials of not completely defiberized paper. At this location there is accomplished a separation of the large size parts from the stock suspension, which then can be conducted through the line or conduit 40 and its branch or branch portion 41 into the good stock vat 18. It is however possible to provide a return flow into a forward part of the installation by means of the line or conduit 42.
Large size pieces can be eliminated from the sieve or screen 37, as such has been schematically represented by the arrow D.
As also apparent from the illustration of the drawing, the second intermediate vat 33 is provided with a circulation system or flow conduit arrangement, generally indicated by reference character 80, in which there is arranged a despeckling or stain removal device 50. This despeckling or stain removing device 50, which is conventional and may be constructed for instance in accordance with the teachings of U.S. Pat. No. 4,011,027, granted Mar. 8, 1977, contains a rotor 60 and a stator 62 having intermeshing rows of teeth 64, so that the stock suspension moving through the despeckling or stain removal device 50 is subjected to a shearing action. Due to this shearing action not completely defiberized paper parts and speckles or stains contained in the individual fibres are defiberized and broken-up. Plastic foils however are only inappreciably comminuted. The outlet line or conduit 51 of the despeckling device 50 leads, as illustrated, back to the intermediate vat 33. Additionally, there is also provided a valve 52 which enables turning-off the despeckling or stain removal device 50. Since the despeckling device 50 possesses a certain pumping action, it is possible to dispense with the use of a pump in the circulation flow system of the despeckling device 50.
As will be apparent from the disclosure, an extremely large proportion of the stock suspension which is formed in the stock slusher or pulper 1 flows through the line 17 directly into the good stock vat 18. Tests have shown that this proportion is in the order of magnitude between 60 to 80 percent. Consequently there is an extensive relieving of load of the parts arranged after the secondary pulper 10, the hydrocyclone 25, the secondary pulper or fiberizer 30 and the despeckling or stain removal device 50. Hence, on the one hand, there is realized an improvement in the mode of operation and, on the other hand, a saving in energy.
As already mentioned, the use of the secondary pulpers or fiberizers 10 and 30 containing screens having suitable size openings or perforations, constitutes a possible and, in fact, preferred construction of the invention. But the invention is in no way limited to the exemplary embodiment. Thus, in place of the secondary pulpers or fiberizers there also can be employed screen devices, such as for instance known thick stock sorting devices, wherein however for obtaining the comminution action there additionally must be provided appropriate equipment. A secondary pulper or fiberizer combines both of these actions in a most simple manner.
While there are shown present preferred embodiments of the the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims,
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A method of preparing waste paper wherein the waste paper is defiberized in water within a stock slusher or pulper. Following the stock pulper there is removed from the stock suspension all of the already available good stock fibres by means of a sieve or screen device. The remainder of the stock suspension is then subjected to a comminution action and is again screened. The screening and comminution can take place in a first fiberizer or secondary pulper having a finer sieve or screen than a conventional secondary pulper. The overflow of the first secondary pulper is infed to a second secondary pulper and the overflow thereof is then fed to a dynamic jarrer or vibrator. Forwardly of the dynamic jarrer there is arranged a vat containing a circulation system of a despeckling device.
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[0001] This application is a National Stage completion of PCT/EP2008/059859 filed Jul. 28, 2008, which claims priority from German patent application serial no. 10 2007 040 040.5 filed Aug. 24, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to a shift element with at least three shift positions for shifting two transmission gear ratios.
BACKGROUND OF THE INVENTION
[0003] In manual shift transmissions, automated manual shift transmissions and dual-clutch transmissions, according to the prior art gears are engaged or preselected by means of conventional claw elements or synchronizers. In such cases, when two gear transmission ratios are adjacent and on one shaft, depending on the position of the shift actuation element one or the other of these two adjacent transmission ratios can be engaged or coupled to the shaft, or in the neutral position of the shift actuation element both gear transmission ratios can be disengaged.
[0004] In some transmission designs, for example dual-clutch transmissions, owing to the arrangement of the transmission ratios it is necessary, when the shift actuation element is in a neutral position, for the two adjacent gear transmission ratios on one shaft both to be shifted to be able to preselect a gear, because of the design. For such transmission designs conventional synchronizers and claw-type shift elements cannot be used, since with such elements the shifting sleeve can always engage only one gear and in the neutral position both gears are disengaged. Below, examples of such transmission designs are described briefly.
[0005] For example, a transmission of the type is known from DE 10232831 A1 by the present applicant. The known dual-clutch transmission, which has a countershaft structure, comprises a driveshaft which can be coupled, via a first clutch, to a shaft of a first part-transmission and, via a second clutch, to a shaft of a second part-transmission, the part-transmissions respectively providing different transmission ratios by means of auxiliary transmissions which can be activated by synchronizers. In this case, for synchronization of a shift element of the respective first auxiliary transmission the corresponding clutch of each part-transmission can be actuated appropriately; in addition, for each part-transmission at least one synchronization clutch is provided.
[0006] From DE 10232835 A1 by the present applicant a dual-clutch transmission for a motor vehicle is known, which comprises at least two transmission groups with shafts, shift elements and gearwheels, such that the transmission groups can be connected in the force flow to a common driveshaft by means of shift-under-load clutches associated with the transmission groups. In this known transmission each transmission group is so configured that it comprises at least two main branches, and the main branches of each transmission group have gearsets downstream from them via which, by means of shift elements, a connection can be formed to a common output gearwheel of a drive output shaft.
[0007] Furthermore, from DE 3233931 C2 a power take-off for a transmission with an incorporated dual clutch is known, such that the power take-off comprises a first transmission mechanism connected or locked to the main take-off shaft and a second transmission mechanism locked or connected to the main running shaft as well as a clutch device, which works in such manner that the transmission mechanisms can be selectively coupled in driving connection with the take-off transmission shaft.
SUMMARY OF THE INVENTION
[0008] The purpose of the present invention is to provide a shift element with at least three shift positions for shifting two transmission gear ratios, in which, in a first end-position corresponding to a first shift position the first transmission gear ratio is shifted and in a second end-position corresponding to a second shift position the second transmission ratio is shifted, by the use of which two adjacent transmission gear ratios on one shaft can be shifted at the same time. The shift element according to the invention should in particular be suitable for dual-clutch transmissions, dual-clutch transmissions of group configuration and planetary transmissions, and should be able to be combined with both synchronizers and claw-type shift elements. In addition, its structure should be compact.
[0009] According to the claims a shift element is proposed, which has at least three shift positions for shifting two transmission gear ratios, with which, in a first-end position corresponding to a first shift position the first transmission ratio is engaged and in a second end-position corresponding to a second shift position the second transmission ratio is engaged, while in the central position corresponding to a third shift position both transmission ratios are engaged.
[0010] In a first embodiment of the invention a shift element derived from a conventional synchronizer device or from a conventional claw-type shift element with no synchronizer device is proposed, in which the axial length of the shifting sleeve is modified in such manner that in the neutral position of the shifting sleeve its inner claw teeth engage simultaneously in the outer claw teeth of the clutch elements of both transmission gear ratios.
[0011] With a shift element of such design, when one gear is disengaged and at the same time another gear is engaged, displacement of the shifting sleeve into the torque-loaded claw teeth is necessary, but this requires high actuator forces.
[0012] In a second embodiment of the invention a shift element derived from a conventional synchronizer device or from a conventional claw-type shift element with no synchronizer device is proposed, which comprises a shifting sleeve divided into two halves or parts so that only half or part of the shifting sleeve has to be moved, by which the associated gear is to be disengaged or engaged. The other shifting sleeve half of the engaged and thus torque-delivering gear remains untouched.
[0013] According to the invention, the shift actuator has three positions in the conventional manner, such that the movement of the two shifting sleeve halves is independent so that depending on the position and movement direction of the shift actuator either one or the other shifting sleeve half is moved. The gear associated with the respective shifting sleeve half is disengaged by a positively locking carrier element on the receptor of the shift actuator, so that decoupling and coupling of the shifting sleeve halves during the shifting or engagement and synchronization of a gear take place in the shift actuator receptor.
[0014] Advantageously, conventional claw teeth can be used on synchronizer elements (if provided), clutch elements, synchronizer rings (if provided) and sliding sleeve halves.
[0015] By virtue of the design concept according to the invention a compact shift element is obtained, which fulfills the above-mentioned requirements regarding the simultaneous shifting of two gears and the alternate disengagement and re-engagement of a respective gear. In that the claw teeth of the components can be adopted as they exist, only the design of the sliding sleeve and its connection to the shift actuator receptor are modified.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Below, an example of the invention is explained in more detail with reference to the attached figures, which show:
[0017] FIG. 1 : Schematic sectioned view of a shift element designed in accordance with a first embodiment of the invention;
[0018] FIGS. 2 and 2A : Schematic sectioned views of a shift element designed in accordance with a second embodiment of the invention, in the central position with a disengaged gear;
[0019] FIGS. 3-3C : Four schematic sectioned views of a shift element according to a third embodiment of the invention, to illustrate the individual shift operations;
[0020] FIG. 4 : Schematic view of a further embodiment of the invention;
[0021] FIG. 5 : Schematic view of a further embodiment of the invention;
[0022] FIG. 6 : Schematic view of another design of a shift element according to the invention;
[0023] FIG. 7 : Schematic view of another design of a shift element according to the invention;
[0024] FIGS. 8-8B : Schematic views of the shift element according to the invention shown in FIG. 7 , to illustrate the re-engagement and synchronization of the disengaged gear by overlapping rotation movements;
[0025] FIGS. 9 and 9A : Schematic views of another design of a shift element according to the invention;
[0026] FIGS. 10 and 10A : Schematic views of a further, advantageous design of a shift element according to the invention;
[0027] FIGS. 11-11B : Schematic views of another advantageous design of a shift element according to the invention, to illustrate the re-engagement and synchronization of the disengaged gear by the driven motion of adjusting blocks;
[0028] FIGS. 12-12C : Schematic views of an alternative embodiment of the shift element shown in FIG. 11 , to illustrate the re-engagement and synchronization of the disengaged gear; and
[0029] FIG. 13 : An overview of the functionality of a conventional synchronizer and the synchronizer concept proposed according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The description below is given with reference to shift elements derived from conventional synchronizer devices; as already explained, however, it is also possible to derive the shift element according to the invention from a conventional claw-type shift element with no synchronizer device, and in that case the functions of the synchronizer element that are relevant for the invention are assumed by a part of the claw shift element arranged fixed on a shaft.
[0031] In a first embodiment of the invention as shown in FIG. 1 , the shift element 1 is in the form of a conventional synchronizer device comprising clutch elements 2 , synchronizing rings 3 and a synchronizer element 4 , in which the axial length of the shifting sleeve 5 is modified such that in the central position of the shifting sleeve 5 its inner claw teeth engage simultaneously in the outer claw teeth of the clutch elements 2 of both adjacent transmission gear ratios or gearwheels 6 , 7 arranged on one shaft. In contrast to a conventional synchronizer, in the central position of the shift element according to the invention both gears are engaged, as can also been seen in FIG. 13 in which the shift element in FIG. 1 is denoted as alternative 1 .
[0032] In the embodiment shown in FIGS. 2 and 2A the shifting sleeve of the shift element 1 is divided and so has two shifting sleeve halves 8 , 9 . In the figure the shift actuator receptor 10 , which forms the connecting member of the shift element 1 to the shift actuator and comprises a positively locking carrier element 11 for the shifting sleeve halves 8 , 9 , is represented schematically. The shift actuator receptor 10 is designed with a 11 shape and has a carrier 14 positioned centrally, so that the sides form the carrier elements 11 .
[0033] According to the invention, axially acting spring elements 12 , 13 are positioned on the inside of the shift actuator receptor 10 between the central carrier 14 of the shift actuator receptor 10 and the inside end faces of the two shifting sleeve halves 8 , 9 . When, now, the left-hand gear is disengaged, the shift actuator receptor 10 is moved to the right, although it takes the left shifting sleeve half 9 with it by means of the carrier element 11 , but the right shifting sleeve half 8 is not moved since, to accommodate the movement of the shift actuator receptor 10 , the spring 12 on the right is compressed. During this the spring force on the shifting sleeve half 8 can be supported against a retaining ring or on the gearwheel. According to the invention, the spring elements 12 , 13 are designed such that the spring force is at least as large as the force required to synchronize and engage the claw teeth.
[0034] In FIG. 2A the shift actuator is in its central position so that both gears are engaged. Thus, the inner claw teeth of the two shifting sleeve halves 8 , 9 engage both in the claw teeth on the synchronizer element 4 and in the claw teeth on each of the clutch elements.
[0035] The mode of operation of the shift element shown will be explained below, considering the example of “disengaging the gear on the left and re-engaging it”. Starting from the neutral position, to disengage the gear on the left the shift actuator is moved to the right so that the carrier element 11 of the shift actuator receptor 10 carries with it the shifting sleeve half 9 on the left to be shifted and pushes it to the right, so that the claw teeth of the left-hand clutch element are now no longer engaged with the inner claw teeth of the left shifting sleeve half 9 as illustrated in FIG. 2 . As can be seen in the figure, the position of the right shifting sleeve half 8 remains unchanged (i.e. the right-hand gear remains engaged) because of the compression of the spring 12 .
[0036] To re-engage the gear on the left, the shift actuator receptor 10 is now moved to the left again, i.e. back to its central position. During this the left shifting sleeve half 9 is pushed to the left by the force of the left spring 13 .
[0037] In contrast to a conventional synchronizer, in the central position of the shift element according to the invention both gears are engaged, as also illustrated in FIG. 13 in which the shift element shown in FIGS. 2 and 2A is denoted as alternative 1 .
[0038] FIGS. 3 , 3 A, 3 B and 3 C show a further embodiment of a shift element according to the invention, in which the shifting sleeve is also divided into two shifting sleeve halves 8 , 9 . In this design as well the shifting sleeve halves 8 , 9 are moved by a carrier element 11 of the shift actuator receptor 10 , but to prevent the conjoint movement of the other shifting sleeve half the shift actuator receptor 10 has on its side facing toward the shifting sleeve halves 8 , 9 two grooves 15 , 16 into which a displacement element 17 can be pressed.
[0039] In addition the inner end faces of the shifting sleeve halves 8 , 9 have chamfers 18 over which the displacement element 17 can be pressed into one of the two grooves 15 , 16 when the shift actuator receptor is actuated; in the neutral position ( FIG. 3C ) the displacement element 17 is positioned between the two inner end faces of the shifting sleeve halves 8 , 9 .
[0040] When the left-hand gear is disengaged, due to the movement of the left shifting sleeve half 9 to the right by the chamfers 18 on the inside end faces of the shifting sleeve halves 8 , 9 the displacement element 17 , which is preferably a ball, is pressed upward into a correspondingly shaped groove 16 in the shift actuator receptor 10 , as illustrated in FIG. 3B . During this the right-hand shifting sleeve half 8 takes up the supporting force of the ball 17 and can rest against a retaining ring 29 or alternatively directly on the gearwheel 6 .
[0041] When, now, the left gear is to be re-engaged, as shown in FIG. 3A the shift actuator receptor 10 is moved back to its central position again and during this the shifting sleeve half 9 is moved by the ball 17 to the left, the force required for synchronization and engagement being transmitted, according to the invention, by the ball 17 . On completion of the synchronization process the ball 17 is pressed back to its original position between the shifting sleeve halves 8 , 9 (bottom right figure), which can be done by a spring force acting radially inward, while the simultaneous pressure on the ball 17 by the oblique faces in the groove 16 of the shift actuator receptor 10 assists this return process of the ball 17 . Preferably, the ball 17 is arranged in a spring ring.
[0042] Alternatively to the design as a ball, the displacement element may have other shapes. For example, the displacement element can be shaped at the bottom (i.e. on its side facing away from the shift actuator receptor) as a cone and at the top (i.e. on its side facing toward the shift actuator receptor) as a cylinder or a square, and the grooves 15 , 16 in the shift actuator receptor 10 are then adapted to match the shape of the displacement element.
[0043] The embodiment shown in FIGS. 3-3C has the advantage of ensuring the best possible interlocking and forced disengagement and engagement processes.
[0044] FIGS. 4 , 5 and 6 show designs according to the invention of the shift element for the secure return movement of the displacement element 17 , even under the influence of centrifugal force.
[0045] FIG. 4 shows a possibility for avoiding the sliding of the ball 17 along the chamfers of the shifting sleeve halves 8 , 9 and the respective groove 15 , 16 in the shift actuator receptor 10 . In this case the ball 17 is held in furrows 19 in the chamfers 18 of the shifting sleeve halves 8 , 9 and the grooves 15 , 16 in the shift actuator receptor 10 during the process of pressing back in or synchronization. This has the advantage that during synchronization a solid movement of the unit consisting of the shift actuator receptor/ball/shifting sleeve half occurs, which prevents sliding of the ball 17 along the oblique surfaces or chamfers 18 .
[0046] The ball 17 must then be moved back into the space between the shifting sleeve halves 8 , 9 , and this can be done for example by a ball/sprung joint ring such that the spring action pulls the ball 17 radially inward.
[0047] Alternatively, as shown in FIG. 5 , a spring leaf 20 with spring strips 21 can be inserted or arranged on the inside of the shift actuator receptor 10 . According to the invention the leaf 20 is secured against axial movement relative to the shift actuator receptor 10 by its contact on both sides against the inner sides of the carrier elements 11 of the shift actuator receptor 10 .
[0048] When a ball or some other displacement element 17 moves radially into one of the grooves 15 , 16 in the shift actuator receptor 10 (i.e. when a gear is disengaged), spring strips 21 on the spring leaf 20 are prestressed, and during the subsequent return and engagement of the gear these press the balls or displacement elements back again into the space between the shifting sleeve 8 , 9 , while the sloping surfaces on the respective groove 15 , 16 in the shift actuator receptor 10 , in passing across the balls or other displacement elements, additionally press them radially inward.
[0049] FIG. 6 illustrates a further principle according to the invention for returning the ball or displacement element. In this case ejector teeth of an ejector tooth array 22 are arranged on the face of the gearwheels 6 , 7 or on the clutch elements 2 , so that for example when the shift actuator receptor 10 is moved to the left in the central position, beyond a certain axial position of the shift actuator receptor 10 the teeth of the ejector tooth array 22 project into the shift actuator receptor 10 through apertures 23 provided for the purpose and so force the displacement element 17 to move radially inward and thus into the space between the shifting sleeve halves 8 , 9 .
[0050] FIG. 7 shows a shift element 1 made according to the invention, in which in order to avoid conjoint movement of the respective other shifting sleeve half 8 or 9 during a shift operation, a twisting motion is superimposed on the axial movement of the shift actuator receptor 10 . The twisting motion of the shift actuator receptor 10 is produced by means of oblique teeth 24 on the synchronizer element 4 , in which inner oblique teeth 25 of the shift actuator receptor 10 engage. The shift actuator is π-shaped and has a centrally positioned carrier 26 with the inner oblique teeth 25 , while its flanks form the carrier elements 11 . In the case when the shift element is configured as a claw-type shift element with no synchronizer rings, the oblique teeth 24 are located on part of the claw shift element that is fixed on the shaft.
[0051] The operation of the shift element shown in FIG. 7 is explained below with reference to FIGS. 8A and 8B , considering the example “disengage and re-engage the gear on the left”.
[0052] A gear is disengaged by the carrier elements 11 on the shift actuator receptor 10 . On the faces of the shifting sleeve halves 8 , 9 and on the central carrier 26 of the shift actuator receptor 10 claws 27 are fixed on the surfaces, which in the central position shown in FIG. 8A must have a defined rotation position relative to one another. The representations in FIGS. 8-8B are plan views of the shift element 1 , sectioned through the shift actuator receptor 10 .
[0053] When for example the left-hand gear is disengaged, the carrier element 11 on the shift actuator receptor 10 carries the left-hand shifting sleeve half 9 with it during its movement to the right. During this, the shift actuator receptor 10 is at the same time rotated relative to the synchronizer element 4 and the shifting sleeve halves 8 , 9 , so that the angular position of the claws 27 relative to one another changes.
[0054] In the example shown, to release the axial path the claws 27 on the right-hand side of the carrier 26 of the shift actuator receptor 10 come to rest directly next to the claws of the right-hand shifting sleeve half 8 ( FIG. 8B ), i.e. the axial distance between the shift actuator receptor 10 and the right-hand shifting sleeve half 8 (i.e. the one which is not to be shifted) has decreased (the right-hand shifting sleeve half has not been moved as well).
[0055] The axial distance between the carrier 26 of the shift actuator receptor 10 and the left-hand shifting sleeve half 9 has not changed, but the angular position of the claws 27 of the two components 9 , 26 has. In particular (see FIG. 8B ) the claws 27 on the left side of the carrier 26 of the shift actuator receptor 10 rest directly against the ends of the claws 27 on the left shifting sleeve half 9 .
[0056] When the gear on the left is to be re-engaged, as the shift actuator receptor 10 moves to the left (i.e. back to its central position) the claws 27 on the left of its carrier 26 press against the face of the left shifting sleeve half 9 to push it back toward the left into its initial position and thereby to synchronize and engage the gear ( FIG. 8 ). During this pushing movement a relative sliding movement on the end faces of the claws 27 takes place due to the rotation, so that at the end of the pushing movement the claws 27 are once again in their initial position shown in FIG. 8A .
[0057] In the example shown in FIGS. 9 and 9A too, a gear is disengaged by the axial movement of the carrier element 11 on the shift actuator receptor 10 . In this case the shift actuator receptor 10 is made radially springy, having strips 32 that spring out radially arranged at its circumference which can move radially outward when the shift actuator receptor 10 moves across whichever of the shifting sleeve halves remains stationary.
[0058] This outward movement is accompanied by the rolling of balls 28 fitted into corresponding grooves 30 , 31 in the springy strips in the shift actuator receptor and in the shifting sleeve halves 8 , 9 . In FIG. 9A the shift element according to the invention is shown in its central position.
[0059] When the left-hand gear is disengaged ( FIG. 9 ) the shift actuator receptor 10 is moved to the right and the balls 28 on the right side (i.e. the balls associated with the shifting sleeve half that is not to be shifted), on the one hand in the grooves 30 in the shift actuator receptor 10 and on the other hand in the grooves 31 of the shifting sleeve half 8 on the right, roll to the right, and at the same time move radially outward due to the special contour of the grooves 30 , 31 .
[0060] Owing to this radial movement and to the springy strips 32 attached at its periphery the shift actuator receptor 10 bends outward, which means that the right-hand shifting sleeve half 9 does not move as well. During this, the spring force acting via the balls 28 on the right-hand shifting sleeve 8 (i.e. the one not being shifted) is supported, according to the invention, on a retaining ring 29 or alternatively on the gearwheel 6 .
[0061] When, now, the left-hand gear is re-engaged, as the shift actuator receptor 10 moves back to its central position it carries the balls 28 on the left and so also the left-hand shifting sleeve half 8 with it toward the left, whereby the left gear can be synchronized and re-engaged. Owing to the contour of the grooves, the right-hand shifting sleeve half 8 does not move as well even though the balls on the right move back to their initial position. In this case the spring force in the springy strips 32 of the shift actuator receptor 10 is designed to be large enough to hold the balls 28 securely in the grooves 30 , 31 during the synchronization and engagement of the gear.
[0062] A further advantageous embodiment of the invention is the object of FIGS. 10 and 10A . This shift actuator receptor 10 is again π-shaped and its flanks form the carrier elements 11 .
[0063] In this case, on the inside of the shift actuator receptor 10 is inserted a sheet 33 of spring steel with springy strips 34 projecting radially inward, which, when the shift element 1 is in its central position, rest against the inner end faces of the shifting sleeve halves 8 , 9 ( FIG. 10A ). The springy strips 34 can in each case pivot in only one direction, namely toward the carrier element 11 for the shifting sleeve half associated with the springy strip 34 concerned. According to the invention, the sheet 33 is secured against axial movement relative to the shift actuator receptor 10 by its contact on both sides against the inner sides of the carrier elements 11 of the shift actuator receptor 10 .
[0064] Below, the operating mode of the shift element shown in FIGS. 10 and 10A will be described considering the example “disengagement and re-engagement of the gear on the left”. The gear is disengaged by axial movement of the carrier elements 11 of the shift actuator receptor 10 . When, now, the left-hand gear is disengaged, the springy strip 34 in contact with the inside end face of the shifting sleeve 8 on the right moves (or bends) radially outward over the latter, so that the right shifting sleeve half 8 is not moved along during this. That is illustrated in FIG. 10 .
[0065] When the gear on the left is re-engaged by a movement of the shifting sleeve holder 10 to the left back to its neutral position, then the shift actuator receptor 10 carries the left-hand shifting sleeve half 9 along with it by virtue of the springy strip 34 bent down and resting against the left shifting sleeve half 9 . When the shift actuator receptor 10 has returned to its central position, the springy strip 34 on the right can bend radially inward so that the initial condition is reproduced.
[0066] In the shift element shown in FIGS. 11A and 11B the conjoint movement of the torque-transmitting shifting sleeve half is prevented by the tilting of tilt-blocks 35 distributed on the periphery of the synchronizer element 4 , which also axially releases the shifting sleeve half to be disengaged. The shift actuator receptor 10 is again π-shaped, and its flanks form the carrier elements 11 .
[0067] According to the invention, the tilt-blocks 35 are arranged in grooves 36 of the synchronizer element 4 in such manner that when they tilt, the ends of the tilt-blocks 35 pivot radially outward or inward. In addition, on the tilt-blocks 35 are provided carriers 37 which engage in grooves on the inside of the shift actuator receptor 10 so that when the shift actuator receptor 10 moves, the tilt-blocks 35 can pivot about their bearing-point in the synchronizer element 4 . In the central position the grooves 36 and the grooves 38 are positioned one above the other. In the case when the shift element is configured as a claw-type shift element without synchronizer rings, the grooves 36 are made in a component of the claw shift element arranged fixed on the shaft.
[0068] Below, the operating mode of the shift element shown in FIGS. 11-11B will be explained considering the example “disengagement and re-engagement of the gear on the left”. The gear is disengaged by moving the carrier elements 11 of the shift actuator receptor 10 axially. The image in FIG. 11A shows the shift actuator receptor 10 in its central position.
[0069] When, now, the left-hand gear is to be disengaged, as the left shifting sleeve half 9 is moved by the carrier element 11 on the shift actuator receptor 10 at the same time the tilt-blocks 35 also pivot. According to the invention, this pivoting process clears an axial path for the left shifting sleeve half 9 to be moved; it can now be disengaged without the tilt-blocks 35 blocking its path. Since the torque-transmitting shifting sleeve half 8 on the right does not move so that its distance from the pivot-point of the tilt-blocks 35 does not change, the right-hand portion of the tilt-blocks 35 can pivot radially inward past the right shifting sleeve half 8 without impediment, as shown in FIG. 11B .
[0070] If, now, the left-hand gear is to be re-engaged, as shown in FIG. 11 the shift actuator receptor 10 is moved back to its central position so that the tilt-blocks 35 pivot back to their initial position. However, during this pivoting of the tilt-block 35 they come in contact with the disengaged, left-hand shifting sleeve half 9 . As the shift actuator receptor 10 moves farther to the left, the returning tilt-blocks 35 push the left shifting sleeve half 9 to the left, so synchronizing and engaging the left-hand gear. Preferably, the inner end faces of the shifting sleeve halves 8 , 9 have chamfers 39 to facilitate the contact conditions.
[0071] Another example of a shift element 1 according to the invention is the object of FIGS. 12A , 12 B and 12 C. In this case, analogously to the example embodiment shown in FIGS. 11-11B , the conjoint movement of the torque-transmitting shifting sleeve half is prevented in that pivoting elements 40 are provided, which are rotated to clear an axial path for the shifting sleeve half to be disengaged. In contrast to the example embodiment according to FIGS. 11-11B , the rotation axes of the pivoting elements 40 extend radially outward, i.e. the rotation planes of the pivoting elements 40 are tangential to the periphery of the synchronizer element 4 ; according to the invention, the pivoting elements 40 are mounted to rotate in the synchronizer element 4 . In the case that the shift element is configured as a claw-type shift element without synchronizer rings, the pivoting elements 40 are mounted on a part of the claw shift element arranged fixed on the shaft.
[0072] FIGS. 12A and 12C show, respectively a sectioned view and a plan view of a section through the shift actuator receptor 10 of the shift element in its central position; FIGS. 12 and 12B show, respectively, a sectioned view and a plan view of a section through the shift actuator receptor 10 when the left-hand gear has been disengaged.
[0073] When the shift actuator receptor 10 moves to the right, the left shifting sleeve half 9 is carried with it by the left-hand carrier element 11 on the shift actuator receptor 10 , so that the pivoting elements 40 , which engage by means of carriers 41 in grooves 42 on the inner side of the shift actuator receptor 10 , are rotated out of their initial position. This releases an axial path to enable the left-hand shifting sleeve half 9 to be disengaged ( FIGS. 12 and 12B ).
[0074] When the shift actuator receptor 10 moves back to its central position, the pivoting elements 40 too turn back to their starting position and, during this, press on the left shifting sleeve half 9 so as to push it back to the left, whereby the left-hand gear is synchronized and engaged.
[0075] Needless to say, any design configuration and in particular any spatial arrangement of the components of the shift element according to the invention, per se and in relation to one another and provided they are technically appropriate, are covered by the protective scope of the present claims, without influencing the function of the shift element as indicated in the claims, even if such configurations are not represented explicitly in the figures or in the description.
Indexes
[0000]
1 Shift element
2 Clutch element
3 Synchronizer ring
4 Synchronizer element
5 Shifting sleeve
6 Gearwheel
7 Gearwheel
8 Shifting sleeve half
9 Shifting sleeve half
10 Shift actuator receptor
11 Carrier element
12 Spring element
13 Spring element
14 Carrier of the shift actuator receptor
15 Groove
16 Groove
17 Displacement element
18 Chamfer
19 Furrow
20 Spring sheet
21 Springy strip
22 Ejector teeth
23 Aperture
24 Oblique teeth on the synchronizer element
25 Inner oblique teeth on the shift actuator receptor
26 Carrier of the shift actuator receptor
27 Claw
28 Ball
29 Retaining ring
30 Groove
31 Groove
32 Strip
33 Sheet
34 Springy strip
35 Tilt-block
36 Groove
37 Carrier
38 Groove
39 Chamfer
40 Pivoting element
41 Carrier
42 Groove
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A shift element comprising at least three shift positions for shifting two gear transmission ratios in which in a first end position, which corresponds to a first shift position, the first gear transmission ratio is engaged and in a second end position, which corresponds to a second shift position, the second gear transmission ratio is engaged, while in the central position, which corresponds to a third shift position, both gear transmission ratios are engaged.
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BACKGROUND OF THE INVENTION
This application relates generally to a burner assembly and more particularly to an improved burner assembly which operates in a manner to stabilize the air flow to the burner and reduce the formation of nitrogen oxides as a result of fuel combustion.
Considerable attention and efforts have recently been directed to the reduction of nitrogen oxides resulting from the combustion of fuel, and especially in connection with the use of coal in the furnace sections of relatively large installations such as vapor generators and the like. In a typical arrangement for burning coal in a vapor generator, several burners are disposed in communication with the interior of the furnace and each operates to burn a mixture of air and pulverized coal. The burners used in these arrangements are generally of the type in which a fuel air mixture is continuously injected through a nozzle so as to form a single relatively large flame, and combustion-supporting, or "secondary" air is introduced towards the burner outlet to insure complete combustion. As a result, the surface area of the flame is relatively small in comparison to its volume, and therefore the average flame temperature is relatively high. However, in the burning of coal, nitrogen oxides are formed by the fixation of atmospheric nitrogen available in the combustion supporting air, which is a function of the flame temperature. When the flame temperature exceeds 2800° F., the amount of fixed nitrogen removed from the combustion supporting air rises exponentially with increases in the temperature. This condition leads to the production of high levels of nitrogen oxides in the final combustion products, which causes severe air pollution problems.
Nitrogen oxides are also formed from the fuel bound nitrogen available in the fuel itself, which is not a direct function of the flame temperature, but is related to the quantity of available oxygen during the combustion process.
In view of the foregoing, attempts have been made to suppress the burner and flame temperatures and reduce the quantity of available oxygen during the combustion process and thus reduce the formation of nitrogen oxides. Attempted solutions have included techniques involving two-stage combustion, flue gas recirculation, the introduction of an oxygen-deficient fuel-air mixture to the burner and the breaking up of a single large flame into a plurality of smaller flames. However, although these attempts singularly may produce some beneficial results they have not resulted in a reduction of nitrogen oxides to minimum levels. Also, these attempts have often resulted in added expense in terms of increase construction costs and have lead to other related problems such as the production of soot and the like.
Other attempts to improve the overall combustion efficiency of the burners include the provision of a vane, or the like, on the outer surface of each burner housing to stabilize the flow of the secondary air towards the burner outlet and into the furnace opening in which the burner is installed. However, these vanes often cause downstream eddy currents to form which suck some of the coal discharging from the burner outlet back towards the vane and compromise the performance of the burner.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a burner assembly which operates in a manner to considerably reduce the production of nitrogen oxides in the combustion of fuel without any significant increase in cost or other related problems.
It is a still further object of the present invention to provide a burner assembly of the above type in which the secondary air supply to the burner is regulated to reduce the quantity of available oxygen during the combustion process and achieve an attendant reduction in the formation of nitrogen oxides.
Another object of the present invention is to provide a burner assembly of the above type in which the secondary air is directed toward the burner outlet in two parallel paths, with register means being disposed in each path for individually controlling the flow of air through each path.
It is a more specific object of the present invention to provide a burner assembly of the above type in which a stabilizer vane is provided for the secondary air which improves the performance of the burner without any deleterious effects.
Toward the fulfillment of these and other objects, the burner assembly of the present invention includes an inlet located at one end thereof for receiving a fuel/air mixture, and an outlet located at the other end for discharging the mixture. Secondary air is directed towards the outlet in parallel paths extending around the burner, and a plurality of register vanes are disposed in each of the paths for regulating the quantity of air flowing through the paths. A stabilizer vane extends from the outer surface of the burner housing and is constructed and arranged to stabilize the secondary air flow without affecting the discharge of the fuel from the burner.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of the presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a sectional view depicting the burner assembly of the present invention; and
FIG. 2 is an end view of the burner assembly of FIG. 1 taken along the line 2--2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring specifically to FIG. 1 of the drawings the reference numeral 10 refers in general to a burner assembly which is disposed in axial alignment with a through opening 12 formed in a front wall 14 of a conventional furnace. It is understood that the furnace includes a back wall and side walls of an appropriate configuration to define a combustion chamber 16 immediately adjacent the opening 12. Also similar openings are provided in the furnace front wall 14 for accommodating additional burner assemblies identical to the burner assembly 10. The inner surface of the wall 14 as well as the other walls of the furnace are lined with an appropriate thermal insulation material 18 and, while not specifically shown, it is understood that the combustion chamber 16 can also be lined with vertically extending boiler tubes through which a heat exchange fluid, such as water, is circulated in a conventional manner for the purposes of producing steam.
It is also understood that a vertical wall is disposed in a spaced parallel relationship with the furnace wall 14 in a direction opposite that of the furnace opening 12 along with correspondingly spaced top, bottom and side walls to form a plenum chamber, or wind box, for receiving combustion supporting air, commonly referred to as a "secondary air," in a conventional manner.
A burner 20 is provided which includes an outer barrel, or tubular member, 22 that extends over an inner tubular member 24 in a coaxial, spaced relationship thereto to define an annular passage 26 which extends towards the furnace opening 12. The end portion of the outer tubular member 22 and the corresponding end portion (not shown) of the inner tubular member 24 are tapered slightly radially inwardly toward the furnace opening 12. A tangentially disposed inlet 28 communicates with the outer tubular member 22 for introducing a mixture of primary air and entrained particulate fuel into the annular passage 26 as will be explained in further detail later.
A pair of spaced annular plates 30 and 32 extend around the burner 20, with the inner edge of the plate 30 terminating on the outer tubular member 22. A liner 34 extends from the inner edge of the plate 32 and in a general longitudinal direction relative to the outer tubular member 22 and terminates adjacent the insulation material 18 just inside the wall 14. An additional annular plate 38 extends around the member 22 in a spaced, parallel relation with the plate 30, to define an inlet for secondary air. An air divider sleeve 40 extends from the inner surface of the plate 38 and between the liner 34 and the member 22 to define two air flow passages 42 and 44.
A plurality of outer register vanes 46 are pivotally mounted between the plates 30 and 32 to control the swirl of secondary air from the wind box to the air flow passages 42 and 44. In a similar manner a plurality of inner-register vanes 48 are pivotally mounted between the plates 30 and 38 to further regulate the swirl of the secondary air passing through the annular passage 44. It is understood that although only two register vanes 46 and 48 are shown in FIG. 1, several more vanes extend in a circumferentially spaced relation to the vanes shown. Also, the pivotal mounting of the register vanes 46 and 48 may be done in any conventional manner, such as by mounting the vanes on shafts (shown schematically in FIG. 1) and journalling the shafts in proper bearings formed in the plates 30, 32 and 38. Also, the position of the vanes 46 and 48 may be adjustable by means of cranks or the like. Since these types of components are conventional they are not shown in the drawings nor will be described in any further detail.
The quantity of secondary air flow from the wind box into the register vanes 46 is controlled by movement of a sleeve 50 which is slidably disposed on the outer periphery of the plate 32 and is movable parallel to the longitudinal axis of the burner 20. An elongated worm gear 52 is provided for moving the sleeve 50 in an axial direction to and from the plate 30. Details of the worm gear 52 are fully disclosed in U.S. Pat. Nos. 4,400,151 and 5,347,937, which are assigned to the assignee of the present invention and which are hereby incorporated by reference. Since these details do not form a part of the present invention they will not be described any further.
The worm gear 52 operates to enable the quantity of combustion supporting air from the wind box passing through the air flow passages 42 and 44 to be controlled by axial displacement of the sleeve 50. A perforated air hood 57 extends between the plates 30 and 32 immediately downstream of the sleeve 50 to permit independent measurement of the air flow to the burner 20.
With reference to the burner 20, four divider blocks (two of which are shown in FIG. 1) are circumferentially spaced in the annular passage 26 in the outlet end portion of the burner to divide the mixture of particulate fuel and entrained primary received from the inlet 28 into five separate streams. Since the details of these divider blocks 58 are fully disclosed in the above-identified '151 patent they will not be described in further detail.
According to a feature of the present invention, a frusto-conical vane 60 extends over the outer tubular member 22. As shown in FIG. 2, the vane 60 extends in a spaced relationship to the member 22 to define an annular space 62. Four support struts 64a-64d, spaced at ninety degree intervals, extend between, and are affixed to, the outer surface of the member 22 and the inner surface of the vane 60 to support the vane over the member 22.
The vane 60 is tapered radially inwardly in a direction towards the outlet end of the nozzle 20 with its smaller diameter extending downstream from its larger diameter and slightly upstream from the end 22a of the outer tubular member 22. Thus, a portion of the air passing through the passage 44 impinges against the inner wall of the vane 60 which serves to direct the latter portion to and through the annular gap 62 and towards the end 22a of the tubular member 22. This air, along with the remaining portion of the air passing through the passage 44 and the air passing through the passage 42, mixes with the streams of combusting fuel/air mixture discharging from the member 22 and supplies sufficient oxygen to insure complete combustion of the fuel. Thus, four flame patterns are formed which then pass into and through the burner opening 12 and into the chamber 16.
In operation of the burner assembly 10, the movable sleeve 50 is adjusted during initial start up to accurately balance the air to the burner 20 with respect to the air introduced to the other burners mounted relative to the wall 14. After the initial balancing, no further movement of the sleeves 50 are needed since normal control of the secondary air to the burner 20 is accomplished by operation of the outer register vanes 46.
Pulverized coal suspended or entrained within a source of primary air is introduced into the tangential inlet 28 where it swirls through the annular chamber 26 and is split into four equally spaced streams by the blocks 58. Suitable igniters (not shown) are provided to ignite this fuel air/mixture to form four separate flame patterns, and the igniters are shut off after steady state combustion has been achieved.
Secondary air from the wind box is admitted through the perforated hood 58 and into the inlet between the plates 30 and 32. The axial and radial velocities of the secondary air is controlled by the register vanes 46 and 48 as the air passes through the air flow passages 42 and 44 and towards the furnace opening 12. A portion of the air passing through the passage 44 impinges against the inner wall of the vane 60 which serves to direct the latter portion to and through the annular gap 62 and towards the end 22a of the tubular member 22. This secondary air, along with the remaining portion of the secondary air passing through the passage 44 and the air passing through the passage 42, mixes with the streams of combusting fuel/air mixture discharging from the member 22 at a location just downstream of the outlet end 22a of the tubular member 22. The total amount of secondary air mixing with the streams of fuel/air mixtures is controlled in the manner described above to insure complete combustion of the fuel.
As a result of the foregoing, several advantages result from the burner assembly of the present invention. For example, the provision of separate register vanes 46 and 48 for the outer and inner air flow passages 42 and 44, along with the disposition of the vane 60 in the passage 44 enables secondary air distribution as well as flame shape to be independently controlled and stabilized, resulting in a significant reduction of nitrogen oxides, and a more gradual and controlled mixing of the secondary air with the mixture of fuel and primary air. Further, the provision of multiple flame patterns, each of which receives the stabilized air from the vane 60, results in a greater flame radiation, a lower average flame temperature and a shorter residence time of the gas components within the flame at a maximum temperature, all of which contribute to reduce the formation of nitric oxides.
It is understood that several variations and additions may be made to the foregoing within the scope of the invention. For example, the number of blocks 58 and therefore the number of flame patterns can vary. Also, the inner tubular member 24 and/or the blocks 58 can be omitted. Also, the burner 20 can be identical to the burner disclosed in the above-mentioned '937 patent in which an internal casting is provided which splits the fuel air mixture into a plurality of streams. Also, since the arrangement of the present invention permits the total volume of air introduced in the above manner to be less than stoichiometric, overfire air ports, or the like can be provided as needed to supply air to complete the combustion.
As will be apparent to those skilled in the art, various other changes and modifications may be made to the embodiments of the present invention without departure from the spirit and scope of the present invention as defined in the appended claims and the legal equivalent.
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A burner assembly in which an inlet is located at one end of a tubular member thereof for receiving a fuel/air mixture, and an outlet is located at the other end of the tubular member for discharging the mixture. Secondary air is directed towards the outlet and a register vanes are provided in the path of secondary air flow for regulating the quantity of air flowing through the paths. A stabilizer vane extends from the outer surface of the burner housing and is constructed and arranged to stabilize the secondary air flow without affecting the discharge of the fuel from the burner.
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TECHNICAL FIELD
[0001] The present invention relates to the field of polymer chemistry and, more specifically with regard to the field of cascade or dendritic polymer chemistry. These polymers are based upon the application of mathematical progressions to organic synthesis and thereby possess well-defined molecular topologies.
BACKGROUND OF THE INVENTION
[0002] The field of cascade polymer chemistry is expanding the traditional synthetic limits into the meso-macro-molecular frontier. Such polymers possess well-defined molecular topologies as they can be constructed in discrete layers rendering upon the molecule discrete, symmetric and consistent chemical characteristics.
[0003] These polymeric structures provide specific micellar molecules.
[0004] The synthesis and spectral features of cascade polymers, also referred to as arborols possessing two-, three- and four-directional microenvironments with functionalized polar outer surfaces, have been recently reported (1-8). Depending on their molecular shape, many of these macromolecules aggregate to form gels or show novel micellar characteristics in aqueous solution (3,7,8). In view of an interest in generating a spherical hydrophilic surface with a compact lipophilic core, the present invention provides a cascade system which in one embodiment emanates from a central adamantane core. This core includes bridgehead positions which have suitable geometry to mimic a tetrahedral nucleus and can be envisioned as an extended methane core. Such a core is an ideal starting point toward four-directional cascade polymers.
[0005] In constructing such spherical polymers, several further problems were uncovered. One such problem related to the generation of a tri-branched monomer which would not cyclize. More specifically, to provide tri-valent branching from a single branch of a polymer, at least two qualities are required. First, there must be directionality such that the monomer combines with the branch so as to expose three branch binding sites for further tiering of the macromolecule. The branches of the macromolecule extending from a central core must also extend sufficiently to be able to allow further reactions therewith for the additional tiering while not cyclizing onto themselves. Cyclizing removes branches from being chemically reactive thereby causing a dead-end to the tiering process. For example, the following reaction sequence generated the polymeric product set forth below.
[0006] Attempted oxidation of compound 11 by a RuO 2 procedure of Irngartinger, et al. (9) resulted in limited success in that complete oxidation was not reproducible.
[0007] Applicant herein provides novel monomers which are ideal in that they do not cyclize and further can be used in a cascade system for producing macromolecular monomers through tetradirectional polymers, particularly on an adamantane, methane equivalent, or four-directional core.
[0008] Further, the present invention provides novel four-directional spherical dendritic macromolecules based on adamantane made in accordance with the novel method set forth herein.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention, there is a method forming an amine monomer of the formula
by the steps of reacting nitromethane and CH 2 ═CHCO 2 -TBu by nucleophilic addition to form the triester nitrotrialkanoate of the formula
and reducing the nitrosubstituent to said amine monomer.
[0010] Further in accordance with the present invention the novel amine monomer can be used to create several novel one, two, three, or four-directional polymers based on the adamantane, or similar core.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention generally will provide a monomer of the formula
wherein R is selected from the group consisting essentially of NH 2 and NO 2 . This novel compound is a building block for novel cascade polymers made in accordance with the inventive method set forth below. Products made in accordance with the present invention can be used in various fields, such as pharmaceutical chemistry, as micelles. However these compounds are used to make unimolecular micelles as opposed to multi-molecular micelles, previously known in the art.
[0012] These monomeric micelles generally have a core and branching which leads from the core. In accordance with the present invention, the branching can be tetra-directional extending from the four bridgehead positions of the core and can be tiered or layered such that a first layer of branching can be combined with the core and then subsequent layers can be added to provide a well-defined molecular topology.
[0013] More specifically, as discussed above, attempted oxidation of the arborol of the formula
by the RuO 2 procedure discussed above met with limited success in that complete oxidation was not reproducible. To circumvent this problem as well as to shorten the overall iterative procedure, the novel building block di-tert-butyl 4-amino-[2-(tert-butoxycarbonylethyl]-heptanedioate was prepared by the following scheme.
A key factor was the bulky nature of the tert-butyl ester, so it was necessary to prevent lactam formation during reduction of the nitro functionality. That is, the following reaction did not occur under the condition conducted in accordance with the present invention.
[0014] An attempt to synthesize the nitro ester precursor by modification of the procedure reported by Bruson and Riener(10) using tert-butyl acrylate in place of the acrylonitrile resulted in a poor yield of about 5%. To circumvent this sluggish nucleophilic addition, the reaction temperature was elevated during the initial addition phase and then maintained at about 70° to 80° C. for one hour. This modification resulted in a 72% yield of the desired triester, which was confirmed by 13 C NMR by the peaks for the quaternary and carbonyl carbons at 92.1 and 170.9 ppm, respectively. The 1 H NMR spectrum showed a singlet at 1.45 ppm assigned to (CH 3 ) 3 CO in a multiplet at 2.21 ppm for the methylene protons. Analysis of the crystal structure ultimately confirmed the analysis.
[0015] The prior art discusses diverse reduction conditions for the conversion of nitroalkanols to aminoalkanols(11). The use of platinum, palladium, or Raney nickel catalyst all resulted in very poor yields and gave mostly recovered nitrotrialkanoate compound. However, a reduction with specially generated T-1 Raney nickel by the process of Domingues, et al. (12) at elevated temperatures (ca. 60° C.) gave an 88% yield of the aminoester after purification. Successful reduction was confirmed by 13 C NMR by an upfield shift for the quaternary carbon at 52.2 ppm. The 1 H NMR spectrum of the aminotrialkanoate showed a singlet at 1.44 ppm for the tert-butyl group, multiplets at 1.68 and 2.26 ppm for the methylene protons and a broad singlet at 5.49 ppm for the amino moiety.
[0016] Since related alkyl esters of the aminotrialkanoate could not be prepared because of facile intramolecular lactam formation during the hydrogenation of the nitro moiety, the tert-butyl ester is ideal in that no cyclization was observed. The advantages of the tert-butyl ester are: a) reduced number of overall steps for cascade synthesis; b) easy preparation on a large scale; c) facile hydrolysis to the desired acids in nearly quantitative yield; and d) the poly tert-butyl esters were easily purifiable solids.
[0017] An example of the use of the tert-butyl ester in a cascade synthesis is as follows. Treatment of adamantanecarbonyl chloride with the aminotrialkanoate as set forth above furnished 71% yield of the desired triester (amine monomer) of the formula
This structure was confirmed by 13 C NMR by the peaks at 172.8 (ester), 177.4 (CONH), and 56.7 ppm (side-quaternary carbon). Hydrolysis of the ester to a triacid was accomplished with about 100% yield by treatment with formic acid. It was identical in all respects to a sample prepared by the above procedure. Application of peptide coupling procedures known in the art of the acid with the aminotrialkanoate in the presence of DCC and 1-hydroxybenzotriazole in dry dimethyl formamide (DMF) afforded a 61% yield of a nonaester(13). The following scheme summarizes the reaction sequence
[0018] The presence of the structure was confirmed by 13 C NMR showing two carbonyl peaks at 172.6 (ester) and 177.0 ppm (CONH) as well as the peaks for the side-chain quaternary carbons at 57.6 and 57.0 ppm thereby confirming the transformation. The specific assignment of internal and external methylene signals was based on the intensity ratios as well as the fine shape, the internal methylenes being broader. The final acid was obtained in a 95% yield by the treatment of the ester with formic acid. The absence of the tert-butyl groups in the NMR spectra and the shift for the carbonyl, 172.6 ppm (ester) to 177.6 ppm (acid) supports the conclusion that hydrolysis occurred.
[0019] A large scale preparation of the nitrotriester and its subsequent reduction to the amine has been developed. Specifically, the nitrotriester 1 was prepared via treatment of nitromethane with slightly more than three equivalents of tert-butyl acrylate in dimethoxyethane (DME). Trace yellow impurities produced in the reaction were easily removed by recrystallization. Removal of these colored contaminants circumvents chromatographic purification of the desired monomer 2.
[0020] Hydrogenation of the nitrotriester 1 to the aminotriester 2 at slightly elevated temperature presented a serendipitous exception to the reduction products of known tertiary, γ-nitroester (Weis et al., 1995). All previously known examples of such reductions readily cyclize to afford the corresponding 2,2′-disubstituted pyrrolidones. Therefore, catalytic hydrogenation conducted under carefully controlled temperature conditions using freshly prepared T-1 Raney Nickel at 45-55° C. provided (ca. 90%) the pure monomer 2.
[0021] The crystalline amine 2 is stable for prolonged periods when stored at ≦15° C., however the presence of solvent or extended storage at 25° C. can result in the formation (about 5-7% over several months) of di-tert-butyl 5-oxo-2,2-pyrrolidinedipropionate (3) (Young, 1993). Attempts to recrystallize 2 were initially frustrated by the thermal cyclization at elevated temperatures, which further dictated that in vacuo solvent removal be performed below 50° C. Subsequently, it has been determined that aminoester 2 can be cyclized quantitatively in the solid state at 105-110° C.; while in solution, cyclization occurs at 65-80° C.
[0000] Experimental Section
[0022] General Comments. Melting point data were obtained in capillary tubes with a Gallenkamp melting point apparatus and are uncorrected. 1 H and 13 C NMR spectra were obtained in CHCl 3 , except where noted, with Me 4 Si as the internal standard (δ=0 ppm), and recorded at either 80 or 360 MHz. Infrared spectral data were obtained on an IBM −38 spectrometer. Elemental analyses were performed by MicAnal Laboratories in Tucson, Ariz.
[0023] Di-tert-butyl 4-Nitro-4-[2-tertbutoxycarbonyl)ethyl]heptanedioate. A stirred solution of MeNO 2 (6.1 g, 100 mmol), Triton B (benzyltrimethylammonium hydroxide, 50% in MeOH; heated to 65° to 70° C. tert-Butyl acrylate (39.7 g, 310 mmol) was added portion wise to maintain the temperature at 70° to 80° C. Additional Titon B (2×1 mL) was added when the temperature started to decrease; when the addition was completed, the mixture was maintained at 70° to 75° C. for one hour. After concentration in vacuo, the residue was dissolved in CHCl 3 (200 mL), washed with 10% aqueous HCl (50 mL) and brine (3×50 mL), and dried MgSO 4 ). Removal of solvent in vacuo gave a pale yellow solid, which was crystallized (95% EtOH) to solid, which was crystallized (95% EtOH) to afford a 72% yield of the triester, as white microcrystals: 33 g; mp 98-100° C.; 1 H NMR δ 1.45 (s, CH 3 , 27 H), 2.21 (m, CH 2 , 12 H); 13 C NMR δ 27.9 (CH 3 , 29.7 CH 2 CO), 30.2 (CCH 2 ), 80.9 CCH 3 ), 92.1 (O 2 NC), 170.9 (CO); IR (KBr) 1542 (NO 2 ), 1740 (CO) cm −1 . Anal. Calcd for C 22 H 39 O 8 N: C, 59.35; H, 8.76; N, 3.14. Found C, 59.27; H, 9.00; N, 3.14.
[0024] Di-tert-butyl 4-Amino-4-[2-(tert-butoxycarbonyl)ethyl]heptanedioate. A solution of the above synthesized nitro triester (4.46 g, 10 mmol) in absolute EtOH (100 mL) with T-1 Raney Ni 12 (4.0 g) was hydrogenated at 50 psi and 60° C. for 24 hours. The catalyst was cautiously filtered through Celite. The solvent was removed in vacuo, affording a viscous liquid, which was column chromatographed (SiO 2 ), eluting with EtOAc to give a 88% yield of the amino triester as a white crystalline solid: 3.7 g; mp 50-52° C.; 1 H NMR δ 1.44 (s, CH 3 , 27 H), 1.78 (m, CH 2 , 12 H); 13 C NMR δ 27.8 (CH 3 ), 29.8 (CH 2 CO), 34.2 (CCH 2 ), 52.2 (H 2 NC), 80.0 (CCH 3 ), 172.8 (CO); IR (KBr) 1745 (CO) cm −1 . Anal. Calcd for C 22 H 41 O 6 N: C, 63.58; H, 9.95; N, 3.37. Found C, 63.72; H, 10.05; N, 3.38.
[0025] 1-[[N-[3-(tert-Butoxycarbonyl)-1,1-bis[2-tertbutoxycarbonyl)ethyl]propyl]amino]carbonyl]adamantane. A solution of 1-adamantanecarbonyl chloride (1 g, 5 mmol), amine monomer (2.1 g, 5 mmol), and Et 3 N (600 mg, 6 mmol) in dry benzene (25 mL) was stirred at 25° C. for 20 hours. The mixture was washed sequentially with aqueous NaHCO 3 (10%), water, cold aqueous HCl (10%), and brine. The organic layer was dried (Na 2 SO 4 ) and then concentrated in vacuo to give residue which was chromatographed (SiO 2 ), eluting first with CH 2 Cl 2 to remove some by-products and then with EtOAc to give a 71% yield of the ester as a white solid: 2 g; mp 84-86° C.; 1 H NMR δ 1.46 (s, CH 3 , 27 H), 1.68-2.1 (m, CH, CH 2 , 27 H), 4.98 (bs, NH, 1 H); 13 C NMR δ 28.0 (CH 3 ), 28.2 (γ-CH), 29.8, 30.1 (NHCCH 2 CH 2 CO), 36.4 (δ-CH 2 ), 39.2 (β-CH 2 ), 41.2 (α-C), 56.7 (NHC), 80.5 (CCH 3 ), 172.8 (COO), 177.4 (CONH); IR (KBr) 3350, 2934, 2846, 1740, 1638, 1255, 1038 cm −1 , Anal. Calcd for C 33 H 55 O 7 N: C, 68.58; H, 9.60; N, 2.43. Found: C, 68.36; H, 9.66; N, 2.36.
[0026] 1-[[N-]3-[[N-[3-(tert-Butoxycarbonyl)-1,1-bis[2-(tert-butoxycarbonyl)ethyl]propyl]-amino]carbonyl]-1,1-bis[2-[[N-[3-(tert-buxtoxycarbonyl)-1,1-bis[2-(tert-buxtoxycarbonyl)-ethyl]propyl]amino]carbonyl]ethyl]propyl]amino]carbonyl]adamatane. A mixture of the triacid 1-[[N-[3-carboxyl-1,1-bix(2-carboxyethyl)propyl]-amino]carbonyl]adamantane (400 mg, 1 mmol) amine monomer (1.45 g, 3.5 mmol), DCC (620 mg, 3 mmol), and 1-hydroxybenzotriazole (400 mg, 3 mmol) in dry DMF (15 ml) was stirred at 25° C. for 48 hours. After filtration of the dicyclohexylurea, the solvent was removed in vacuo. The residue was dissolved in CH 2 Cl 2 (50 mL) and sequentially washed with cold aqueous HCl (10%), water, aqueous NaHCO 3 (10%), and brine. The organic phase was dried (Na 2 SO 4 ). Removal of solvent in vacuo gave a thick viscous residue, which was flash chromatographed (SiO 2 ) eluting first with EtOAc/CH 2 Cl 2 (1:1) then with 5% MeOH in EtOAc, furnished A 61% yield of the ester, as a white solid: 970 mg; mp 115-118° C.; 1 H NMR δ 1.42 (s, CH 3 , 81 H), 1.64-2.20 (m, CH, CH 2 , 63 H), 5.58 (bs, NH, 4H) 13 C NMR δ 27.9 (CH 3 ), 28.4 (γ-CH), 29.6, 30.0 (NHCCH 2 CH 2 COO), 31.6, 32.2 (NHCCH 2 CH 2 CONH), 36.6 (γ-CH 2 ), 39.2 (β-CH 2 ), 41.1 (α-C), 57.0 (NHCCH 2 CH 2 COO), 57.6 (NHCCH 2 CH 2 CONH), 80.3 CCH 3 ), 172.6 (COO), 177.0 (CONH); IR (KBr) 3348, 2936, 2850, 1740, 1665, 1260, 1040 cm −1 . Anal. Calcd for C 87 H 148 O 22 N 4 : C, 65.22; H, 9.31; N, 3.50. Found: C, 65.41; H, 9.30; N, 3.39.
[0027] 1-[[N-[3-[[N-[3-Carboxy-1,1-bis(2-carboxyethyl)propyl]amino]carbonyl]-1,1-bix[2-[[N-[3-carboxy-1,1-bix(2-carboxyethyl)propyl]-amino]carbonyl]ethyl]propyl]amino]carbonyl]-adamantane. A solution of the above tert-butyl ester (800 mg, 500 μmol) in formic acid (96%, 5 mL) was stirred at 25° C. for 12 hours. The solvent was removed in vacuo to give a residue; toluene (5 mL) was added and the solution was again evaporated in vacuo to azeotropically remove residual traces of formic acid. The resulting white solid was extracted with warm acetone (5×50 mL). The combined extract was filtered (SiO 2 ), eluting with acetone. The residue obtained after concentration was dissolved in aqueous NaOH (10%) and acidified with concentration HCl to give 95% yield of the acid as a white solid: 520 mg, mp 346° C. dec; 1 H NMR (Me 2 SO-d 6 ) δ 1.82-2.40 (m, CH, CH 2 , 63 H), 4.45 (bs, OH, 9 H, exchanged with D 2 O), 6.28 (bs, NH, 4H); 13 C NMR (Me 2 SO-d 6 ) δ 29.6 (γ-CH), 30.2 (NHCCH 2 CH 2 COOH), 31.0, 32.4 (NHCCH 2 CH 2 CONH), 37.8 (δ-CH 2 ), 40.1 (β-CH 2 ), 42.5 (α-C), 58.0 (NHCCH 2 CH 2 CONH), 58.4 (NHCCH 2 CH 2 COOH), 177.6 (COOH), 179.8 (CONH); IR (KBr) 3360, 3340-2600, 2900, 1744, 1690, 1245, 1090 cm −1 . Anal. Calcd for C 51 H 76 O 22 N 4 : C, 55.83; H, 6.98; N, 5.11. Found: C, 55.71; H, 7.04; N, 4.98.
[0028] The monomers of the present invention can be used for the design and synthesis of novel dendritic polymers which are one, two, three, or four-directional. In accordance with the present invention, the monomers can be used to synthesize four-directional spherical dendritic macromolecules based on adamantane. The use of the aminotrialkanoate monomer offers several advantages. The t-butyl ester intermediates are easily purified solids. Further, only two steps are required to progress from generation to generation.
[0029] A specific example of a synthesis is as follows. An acid chloride of the following formula
is treated with the aminotrialkanoatee present invention to afford a dodecaester of the following formula
wherein R=t-Bu.
[0030] The dodecaester was hydrolyzed in good yield with 96% formic acid to yield the corresponding dodecaacid.
[0031] Addition of further tiers was easily obtained by the coupling of the dodecaacid and further layers of the aminotrialkanoate with DCC an 1-HBT to afford the ester wherein R=TBU. Upon hydrolysis, the ester quantitatively generated the corresponding next tiered polyacid.
[0032] A specific example of the method of forming the above-mentioned acid moiety is as follows.
[0033] 1,3,5,7-Tetrakis{[N-[3-(tert-butoxycarbonyl)-1,1-bis[2-(tert-butoxycarbonyl)ethyl]propyl]amino]carbonyl}-adamantane. A mixture of adamantanetetra-carboxylic acid (78 mg, 250 μmol) and freshly distilled SOCl 2 (2 mL) was refluxed for 4 hours. Excess of SOCl 2 was removed in vacuo, benzene (5 mL) was added, and the solution was concentrated in vacuo to yield the corresponding tetraacyl chloride, as a white solid.
[0034] Crude 1,3,5,7-Tetrakis(chlorocarbonyl) adamantane, amine monomer (450 mg, 1.1 mmol), and Et 3 N (110 mg, 1.1 mmol) in dry benzene (10 mL) were stirred at 25° C. for 20 hours. Additional benzene (40 mL) was added, and the mixture was sequentially washed with aqueous NaHCO 3 (10%), water, cold aqueous HCl (10%), and brine. The organic phase was dried (Na 2 SO 4 ) and then concentrated in vacuo to furnish a viscous oil, which was chromatographed (SiO 2 ), eluting with 5% MeOH in EtOAc to generate a 61% yield of the dodecaester, as a white solid: 290 mg; mp 105-107° C.; 1 H NMR δ 1.40 (s, CH 3 , 108 H), 172 (s, CH 2 , 12 H), 2.24 (m, CH 2 , 48 H), 5.88 (bs, NH 4 H); 13 C NMR δ 28.1 (CH 3 ), 30.0, 30.4 (CCH 2 CH 2 COO), 39.0 (β-CH 2 ), 42.8 (α-C), 57.1 (HNC), 80.2 (CCH 3 ), 173.1 (COO), 177.6 (CONH); IR (KBr) 3348, 2930, 2845, 1740, 1645, 1260, 1038 cm −1 . Anal. Calcd for C 102 H 172 O 28 N 4 : C, 64.38; H, 9.12; N, 2.95. Found: C, 64.52; H, 8.91; N, 2.86.
[0035] 1 , 3 , 5 , 7 -Tetrakis{[N-[3-carboxy-1,1-bis(2-carboxyethyl)propyl]amino]carbonyl}-adamantane. A solution of the dodecaester (190 mg, 100 μmol) in formic acid (96%, 2 mL) was stirred at 25° C. for 20 hours. Excess solvent was removed in vacuo, and toluene (3×2 mL) was added. The solvents were removed in vacuo to give a 94% yield of the dodecaacid, as a white solid: 115 mg; mp 282-284° C. dec; 1 H NMR (D 2 O) δ 1.84 (s, CH 2 , 12H), 2.34 (m, CH 2 , 48H); 13 C NMR (D 2 O) δ 30.1 (CCH 2 CH 2 COOH), 38.8 (β-CH 2 ), 42.7 (α-C), 58.6 (HNC), 177.8 (COOH), 180.4 (CONH); (KBr) 3360, 3330-2600, 2903, 1745, 1690, 1245, 1090 cm −1 . Anal. Calcd for C 54 H 76 O 28 N 4 : C, 52.75; H, 6.23; N, 4.56. Found: C, 52.59; H, 6.22; N, 4.51.
[0036] 1,3,5,7-Tetrakis{[N-[3-[[N-[3-(tert-butoxycarbonyl)-1,1-bis[2-(tert-butoxycarbonyl)-ethyl]propyl]amino]carbonyl]-1,1-bis[2-[[N-[3-(tert-butoxycarbonyl)-1,1-bis[2-(tert-butoxycarbonyl)ethyl]propyl]amino]carbonyl]-ethyl]propyl]amino]carbonyl}adamantane. A mixture of the dodecaacid (74 mg, 60 μmol), the amine monomer (330 mg, 790 μmol), dicyclohexyl-carbodiimide (DCC; 150 mg, 720 μmol), and 1-hydroxybenzotriazole (100 mg, 740 μmol) in dry DMF (3 mL) was stirred at 25° C. for 48 hours. After filtration of dicyclohexylurea, the solvent was removed in vacuo to give a residue, which was dissolved in EtOAc (25 mL) and was sequentially washed with cold aqueous HCl (10%), water, aqueous NaHCO 3 (10%), and brine. The organic phase was dried (Na 2 SO 4 ) and concentrated in vacuo, and the residue was chromatographed (SiO 2 ), eluting first with EtOAc/CH 2 Cl 2 (1:1) to remove some impurities and then with 5% MeOH in EtOAc to furnish a 58% yield of the ester, as a white solid: 200 mg; mp 138° C.; 1 H NMR δ 1.40 (s, CH 3 ); 13 C NMR δ 28.1 (CH 3 ), 30.0 (CCH 2 CH 2 CONH), 29.8, 30.2 (CCH 2 CH 2 COO), 38.9 (β-CH 2 ), 42.4 (α-C), 57.2 (CCH 2 CH 2 COO), 57.6 (CCH 2 CH 2 CONH), 80.0 (CCH 3 ), 172.8 (COO), 177.8 (CONH); IR (KBr) 3350, 2938, 2846, 1740, 1680, 1260, 1045 cm −1 . Anal. Calcd for C 318 H 544 O 88 N 16 : C, 63.64; H, 9.14; N, 3.74. Found: C, 63.28; H, 8.96; N, 3.77.
[0037] 1,3,5,7-Tetrakis{[N-[3-[[N-[3-carboxy-1,1-bis(2-carboxyethyl)propyl]amino]carbonyl]-1,1-bis[2-[[N-[3-carboxy-1,1-bis(2-carboxyethyl)-propyl]amino]carbonyl]ethyl]propyl]amino]-carbonyl}adamantane. A solution of the ester (150 mg, 25 μmol) in formic acid (96%, 2 mL) was stirred at 25° C. for 20 hours. Workup and purification, similar to that of the dodecaacid, gave (95%) the corresponding acid, as a very hygroscopic solid: mp 350-354° C. dec; 1 H NMR (D 2 O) δ 1.80 (s, CH 2 , 12 H), 2.18-2.41 (m, CH 2 , 192 H) 13 C NMR (D 2 O) δ 30.2 (CCH 2 CH 2 COOH), 30.8, 31.6 (CCH 2 CH 2 CONH), 39.1 (β-CH 2 ), 42.8 (α-C), 58.1 (CCH 2 CH 2 CONH), 58.5 (CCH 2 CH 2 COOH), 178.0 (COOH), 180.2 (CONH); IR (KBr) 3360, 3340-2600, 2920, 1745, 1685, 1240, 1060 cm −1 .
[0038] Large Scale Preparation of Di-tert-butyl 4-[2-(tert-butoxycarbonyl)ethyl]-4-nitroheptane-dicarboxylate (1). A 5-liter 3-necked flask, equipped with a 500 mL addition funnel, a thermometer, a reflux condenser and a 2-inch magnetic stirring bar was charged with 1,2-dimethoxyethane (DME, 500 mL) and MeNO 2 (122 g, 108.3 mL, 2 mol). The solution was heated to 65-70° C., and Triton-B (20 mL, 40% in MeOH) was added. Tert-butyl acrylate (794 g, 908 mL, 6.20 mol) was added at such a rate to maintain a temperature of 75-85° C. The addition was completed within 2 to 2.5 hours. When the temperature was maintained at 70-80° C. for two hours, the solution was decanted from insoluble polymeric material (which adheres to the wall of the flask) and concentrated in vacuo. The resulting light yellow residue was dissolved in ether (2.5 L), washed with ice cold 10% aqueous HCl (2×200 mL), an aqueous saturated NaHCO 3 (2×200 mL), and water (2×200 mL), then dried and clarified [Na 2 SO 4 (100 g) with celite (10 g)]. The ether was removed in vacuo to give a solid mass, which was dissolved in warm ethanol (ca. 1.3 L). The solution was allowed to cool and maintained at 0° C. for 24 hours. The resultant colorless crystals, were collected, washed with precooled methanol (500-600 mL) to remove any residual colored impurities, and dried in vacuo to afford 668-721 g (75-81%) of the white crystalline 1; mp 99-100° C., lit (Newkome et al., 1991) mp 98-100° C. 1 H NMR: δ 1.45 (s, CH 3 , 27H), 2.21 (m, CH 3 , 27H), 2.21 (m, CH 2 , 12H); 13 C NMR: δ 27.9 (CH 3 ), 29.7 (CH 2 CO), 30.2 (CCH 2 ), 80.9 (CCH 3 ), 92.1 (CNO 2 ), 170.9 (CO 2 ).
Di-tert-butyl 4-[2[(tert-butoxycarbonyl)ethyl]-4-aminoheptanedicarboxylate (2)
[0039] A. Preparation of T-1 Raney Nickel Catalyst (Dominguez et al., 1961). Caution should be maintained as this catalyst is easily handled when wet; however, it is extremely pyrophoric when dried and exposed to air. To 705 mL of water in a 2 L beaker rapidly stirred using a 2-inch magnetic stirring bar was added NaOH pellets (75 g). After dissolution, aluminum nickel alloy [30 g, Aldrich Chemical Co. (22,165-1), Raney R-type alloy] was added in one portion to the hot solution. There was a vigorous evolution of hydrogen and the temperature rose to ca. 85-90° C.; stirring was continued for one hour. The beaker was covered with a watch glass, and the supernatant alkaline solution was carefully decanted from the black catalyst. Distilled water (300-400 mL) was added, stirred for one to two minutes, and then decanted. This procedure was repeated four times. The catalyst was transferred into a 250 mL beaker and washed with absolute ethanol (5×150-200 mL); each time the catalyst was allowed to settle before the supernatant ethanol was decanted. The moist catalyst was used immediately.
[0040] B. Reduction Procedure. To a Parr hydrogenation bottle was added ethanol (25 mL), followed by the above freshly prepared catalyst [which should be covered (50-100 mL) with ethanol to ca. 75% of the total flash volume. The hydrogenation was performed at an initial pressure of 60 psi at 50-55° C., and generally required 45-75 minutes. Nitrotirester 1 is quite insoluble in ethanol while amine 2 is soluble. External cooling may be necessary so that the temperature does not exceed 55° C. The catalyst was removed by filtration through a sintered glass funnel, then washed with ethanol (50-80 ml) (Catalyst Destruction). If there are traces of catalyst in the filtrate, filtration must be repeated. The solvent was removed in vacuo (0.1 mm) to yield an oil, which was transferred to a crystallizing dish and allowed to solidify in vacuo to give 41.5-44.1 g (89-93%) of 2 as a white crystalline mass, mp 51° C., lit. (Newkome et al., 1991) mp 51-52° C. 1 H NMR: δ 1.44 (s, CH 3 , 27 H), 1.78 (m, CH 2 , 12H); 13 C NMR: δ 27.8 (CH 3 ), 29.8 (CH 2 CO), 34.2 (CCH 2 ), 52.2 (CNH 2 ), 80.0 (CCH 3 ), 172.8 (CO 2 ); MS m/e 415.4 (M + +1, 20).
[0041] Amine 2 can be cyclized upon heating to 110° C. for 48 hours to yield (100%) lactam 3, mp 132-133° C., lit. (Young, 1993) mp 131-132° C. 1 H NMR: δ 1.44 (s, CH 3 , 18 H), 1.83 (t, J=7.2 Hz, CH 2 CO, 4H), 1.92 (t, J=8.0 Hz, CH 2 CONH, 2H), 2.26 (t, J=7.2 Hz, CCH 2 , 4H), 2.38 (5, J=8.0 Hz, CCH 2 CH 2 CH 2 CONH, 2H), 6.92 (s, NH, 1H); 13 C NMR: δ 27.9 (CH 3 ), 30.1 (CH 2 O), 30.2, 30.25 [CH 2 CH 2 (ring)], 34.6 (CH 2 CH 2 CO 2 ), 60.6 (HNC), 80.6 (CO 2 C), 172.3 (CO 2 ), 177.2 (CONH); IR 1723, 1707 (C═O cm −1 . Anal. Calcd. for C 18 H 31 NO 5 ; C, 63.32; H, 9.15; N, 4.10. Found: C, 63.52; H, 9.25; N, 4.28.
[0042] The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.
[0043] Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
REFERENCES
[0000]
1. Newkome, G. R.; Yao, Z.-q.; Baker, G. R.; Gupta, V. K. J. Org. Chem. 1985, 50, 2003.
2. Newkome, G. R.; Baker, G. R.; Saunders, M. J.; Russo, P. S.; Gupta, V. K.; Yao, Z.-q. Y.; Miller, J. E.; Bouillion, K. J. Chem. Soc., Chem. Commun. 1986, 752.
3. Newkome, G. R.; Baker, G. R.; Aria, S.; Saunders, M. J.; Russo, P. S.; Theriot, K. J.; Moorefield, C. N.; Rogers, L. E.; Miller, J. E.; Lieux, T. R.; Murray, M. E.; Phillips, B.; Pascal, L. J. Am. Chem. Soc. 1990, 112, 8458.
4. Newkome, G. R.; Yao, Z.-q.; Baker, G. R.; Gupta, V. K.; Russo, P. S.; Saunders, M. J.; J. Am. Chem. Soc. 1986, 108, 849.
5. Newkome, G. R.; Hu, Y.; Saunders, M. J.; Fronczek, F. R. Tetrahedron Lett. 1991, 32, 1133.
6. Newkome, G. R.; Moorefield, C. N.; Baker, G. R.; Johnson, A. J.; Behera, R. K. Angew. Chem. 1991, 103, 1205; Angew. Chem., Int. Ed. Engl. 1991, 30, 1176.
7. Newkome, G. R.; Moorefield, C. N.; Baker, G. R.; Saunders, M. J.; Grossman, S. H. Angew. Chem. 1991, 103, 1207; Angew. Chem., Int. Ed. Engl. 1991, 30, 1178.
8. Newkome, G. R.; Lin, X. Macromolecules 1991, 24, 1443.
9. Ingartinger, H.; Reimann, W. J. Org. Chem. 1988, 53, 3046.
10. Bruson, H. A.; Riener, T. W. J. Amer. Chem. Soc. 1943, 65, 23.
11. Gakenheimer, W. C.; Hartung, W. H. J. Org. Chem. 1944, 9, 85. Noland, W. E.; Kneller, J. F.; Rice, D. E. Ibid. 1957, 22, 695. Fanta, P. E.; Smat, R. J.; Piecz, L. F.; Clemens, L. Ibid. 1966, 31, 3113. Controulis, J.; Rebstock, M. C.; Crooks, H. M., Jr. J. Am. Chem. Soc. 1949, 71, 2463. Wheatly, W. B. Ibid. 1954, 76, 2832. Newman, M. S.; Edwards, W. M. Ibid. 1954, 76, 1840. Herz, W.; Tocker, S. Ibid. 1955, 77, 3554. Baer, H. H.; Fischer, H. O. L. Ibid. 1960, 82, 3709.
12. Domingues, X. A.; Lopez, I. C.; Franco, R. J. Org. Chem. 1961, 26, 1625.
13. Bodanszky, M.; Bodanszky, A. The Practice of Peptide Synthesis in Reactivity and Structure Concepts in Organic Chemistry; 1984; Vol. 21, p. 145.
14. C. D. Weis and G. R. Newkome, Synthesis, 1053 (1995).
15. J. K. Young, Ph. D. (USF) Dissertation, 1993.
16. G. R. Newkome, R. K. Behera, C. N. Moorefield, G. R. Baker, J. Org. Chem., 56, 7162 (1991).
17. Catalyst destruction following the hydrogenation can be effected by direct addition of the moist material to a 5%. aqueous HCl solution.
|
A method for forming cascade polymers specifically utilizing the amine monomer of the formula
The monomer is made by initially reacting nitromethane and CH 2 ═CHCO 2 -TBu by nucleophilic addition to form the triester nitrotrialkanoate of the formula
and then reducing the nitrosubstituent to afford the said amine monomer.
| 2
|
CROSS REFERENCE TO RELATED U.S. APPLICATION
[0001] This patent application relates to, and claims the priority benefit from, U.S. Provisional Patent Application Ser. No. 61/064,647 filed on Mar. 18, 2008, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to synthesis of polyolefin (polyethylene, polypropylene and their copolymers) thermosets using the reaction of maleic anhydride, or other, functionalized polyolefin waxes obtained using metallocene or Ziegler Natta catalysts, or other methods, with a polyamine.
BACKGROUND OF THE INVENTION
[0003] Current methods for crosslinked polyolefin synthesis include a first method which involves grafting of silane moieties on the high molecular weight polymer using reactive extrusion and subsequent curing of silane groups by moisture curing in the presence of a suitable catalyst. Synthesis of copolymer of olefin and vinyl silane are also reported. However, in both cases high molecular weight polymer needs to be extruded into the end use article and then moisture cured to generate Si—O—Si linkages. The moisture curing is a very slow process taking several hours to days. The diffusion of moisture limits the thickness and shape of the end use article.
[0004] A second method involves the extruding the high molecular weight polyolefin into the end use article which is then irradiated with high energy electron beam. The electron beam creating reactive sites on the polymer chains which then couple to generate crosslinks. The electron beams are expensive and penetration of the beam once again limits the thickness and shape of end use article.
[0005] A third method involves generation of crosslinks using free radicals produced by dissociation of organic molecules such as peroxides. These organic molecules are added to the high molecular weight polymer during extrusion and the end use article is formed. Subsequent heating of the article helps dissociation of the small organic molecule into free radicals which then generate active sites on the polymer capable of coupling to form crosslinks. However, it is not always easy to delay the dissociation of peroxides until the shape of the article is given. Premature decomposition and subsequent prolonged attempts at thermally shaping the polymer can result in a phenomenon called “scorching”.
[0006] In all three processes, a common factor is the extrusion of high molecular weight polymer which is an energy intensive operation. The present invention is related to the synthesis of high molecular thermoset polyolefin from low molecular weight waxes with very low viscosities. The low viscosity implies relatively large size articles and intricate designs could be produced with less energy. Fast reaction rates of anhydride and amines would result in fast curing of the product. Finally, the presence of functional groups on the polyolefin wax and diamines would facilitate the insertion of any inorganic reinforcements into such thermosets.
[0007] Therefore, it would be very advantageous to produce polyolefin (polyethylene, polypropylene and their copolymers) crosslinked thermosets using maleic anhydride functionalized polyolefin waxes, obtained by using metallocene or Zeigler Natta catalysts, with alkyl and alkyl ether diamines.
SUMMARY OF THE INVENTION
[0008] Polyolefin (polyethylene, polypropylene and their copolymers) thermosets have been created using the reaction of novel maleic anhydride functionalized waxes [1] obtained by using metallocene or Zeigler Natta catalysts with alkyl and alkyl ether diamines. These materials have a very fast reaction rate. The unreacted metallocene waxes possess low melting temperatures (80° C.-165° C.) and very low viscosities in the melt state allowing them to be processed using equipment commonly used for reaction injection molding of polyurethane materials. Two component systems can be mixed just prior to application (molding, adhesives, coatings, etc.) and cured in place. This eliminates the need to process these materials using conventional thermoplastic processing equipment such as extruders and injection molders. The thermoset materials created will maintain their mechanical integrity at temperatures above the melting point of the starting materials depending on the extent of reaction.
[0009] These materials and the associated processes can be used to produce molded articles, novel adhesives, coatings, sealants, etc. The elimination of the need to use conventional thermoplastic processing equipment is expected to lead to the creation of new applications and markets for these types of materials.
[0010] Thus the present invention provides cross linked polyolefin thermoset synthesized by a method comprising reaction of a maleic anhydride functionalized reactive polyolefin wax with a polyamine.
[0011] Thus, an embodiment of the present invention provides a cross linked polyolefin thermoset material, comprising maleic anhydride functionalized reactive polyolefin wax cross linked with a polyamine.
[0012] The polyolefin in the polyolefin wax may be any one of polyethylene, polypropylene and their copolymers, to mention a few non-limiting examples. The polyamine may be any one of primary or secondary alkyl polyamines, alkyl ether polyamines and aryl polyamines to mention a few non-limiting examples.
[0013] The cross linked polyolefin thermoset material may be used to produce any one of molded articles, adhesives, coatings, and sealants to mention a few non-limiting examples.
[0014] An embodiment of the present invention provides a cross linked polyolefin thermoset material, comprising maleic anhydride functionalized reactive polyolefin wax cross linked with a polyol. The polyol may be any one of alkyl polyols, alkyl ether polyols and aryl polyols to mention some non-limiting examples.
[0015] An embodiment of the present invention provides a cross linked polyolefin thermoset synthesized by a method comprising reaction of a maleic anhydride functionalized reactive polyolefin wax with one of a polyamine and a polyol at a temperature sufficient to cross link the maleic anhydride functionalized reactive polyolefin wax with said one of the polyamine and the polyol.
[0016] The present invention also provides a method of synthesizing a cross linked polyolefin thermoset product, comprising:
[0017] a) simultaneously pumping at an elevated temperature a melt stream of maleic anhydride functionalized reactive polyolefin wax and a melt stream of polyamine through a static mixer, also maintained at an elevated temperature, to form a mixture; and
[0018] b) dispensing the mixture from the static mixer and heating the mixture at a second temperature for a suitable period of time to induce a desired amount of crosslinking between the maleic anhydride functionalized reactive polyolefin wax and the polyamine to produce a crosslinked polyolefin thermoset product.
[0019] In this aspect step b) may include dispensing the mixture into a product mold heated to said second temperature for said suitable period of time to produce the crosslinked polyolefin thermoset product. Alternatively, step b) may include dispensing the mixture as a coating onto a surface and heating the coating to said second temperature for said suitable period of time to produce a layer of the cross linked polyolefin thermoset product on the surface.
[0020] The first temperature may be from about 140° C. to about 250° C., and the second temperature may be from about 140° C. to about 250° C.
[0021] The present invention also provides a method of synthesizing a cross linkable polyolefin thermoset mixture, comprising:
[0022] a) mixing a maleic anhydride functionalized reactive polyolefin wax and a polyamine at a first temperature at which both the anhydride functionalized reactive polyolefin wax and the polyamine are in a solvent free melt state to form a cross linkable polyolefin thermoset mixture; and
[0023] b) packaging the mixture in a package for distribution.
[0024] The first temperature may be in a range from about 140° C. to about 250° C., and depending on the materials used the package may need to package the mixture in an air tight package.
[0025] The cross linkable polyolefin thermoset mixture may then be dispensed from the package onto an object and heating said mixture to a second temperature to cross link the maleic anhydride functionalized reactive polyolefin wax and polyamine to form a cross linked thermoset. The second temperature may be in a range from about 140° C. to about 250° C.
[0026] Alternatively, the cross linkable polyolefin thermoset mixture may be dispensed from the package into a product mold and heating the mixture to a second temperature to cross link the maleic anhydride functionalized reactive polyolefin wax and polyamine to form a cross linked thermoset product. The second temperature may be in a range from about 140° C. to about 250° C.
[0027] A further understanding of the functional and advantageous aspects of the invention can be realized by reference to the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention will be more fully understood from the following detailed description thereof taken in connection with the accompanying drawings, which form part of this application, and in which:
[0029] FIG. 1 a shows the spectra of blends of PEMA4351 and PE4201;
[0030] FIG. 1 b is a plot of relative peak heights vs. blend composition;
[0031] FIG. 2 a shows the Fourier Transform Infrared (FTIR) spectra for PEMA4351 reacted with EDR176 diamine;
[0032] FIG. 2 b shows a plot of relative peak height of 1860 and 1792 peaks against NH 2 /MA;
[0033] FIG. 3 shows time sweeps for (a) dilute (40 g/160 ml) and (b) concentrated (60 g/120 ml) systems; 140 C; γ°=5%; ω=1 rad/s;
[0034] FIG. 4 shows frequency sweeps for (a) dilute (40 g/160 ml) and (b) concentrated (60 g/120 ml) systems; 140° C.; γ°=5%; and
[0035] FIG. 5 shows stress relaxation for (a) dilute (40 g/160 ml) and (b) concentrated (60 g/120 ml) systems; 140° C.; γ°=5%;
[0036] FIG. 6 shows gel contents for reaction product NH 2 /MA 1.5 vs. the cure time at different temperatures;
[0037] FIG. 7 shows the reaction products for (a) maleic anhydride and amine;
[0038] FIG. 8 shows the FTIR spectra for reaction products NH 2 /MA 1.5 compression molded for varying time at 160° C.; and
[0039] FIG. 9 shows the change in FTIR relative peak heights for imide and amide functionalities as a consequence of processing time at 160° C.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Generally speaking, the systems described herein are directed to the synthesis of polyolefin thermosets using the reaction of novel maleic anhydride functionalized polyolefin waxes [reference 1 for example]. As required, embodiments of the present invention are disclosed herein. However, the disclosed embodiments are merely exemplary, and it should be understood that the invention may be embodied in many various and alternative forms. The Figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may have been eliminated to prevent obscuring novel aspects. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. For purposes of teaching and not limitation, the illustrated embodiments are directed to synthesis of polyolefin thermosets using the reaction of novel maleic anhydride functionalized metallocene waxes with a polyamine.
[0041] As used herein, the term “about”, when used in conjunction with ranges of concentrations or other physical properties, temperatures or other chemical characteristics, is meant to cover slight variations that may exist in the upper and lower limits of the ranges of dimensions of particles so as to not exclude embodiments where on average most of the dimensions are satisfied but where statistically dimensions may exist outside this region. It is not the intention to exclude embodiments such as these from the present invention.
[0042] The present invention will now be illustrated using the following non-limiting examples, which are for purposes of illustrating the invention and is not meant to limit the invention to these particular examples.
Example 1
[0043] This above example illustrate that it is possible to produce thermosets of polyolefins by carrying out reactions between maleic anhydride functionalized olefin with polyetherdiamines in solution.
Experimental
Materials
[0044] The maleic anhydride functionalized polyolefin (PEMA4351) and ungrafted polyethylene wax (PE4201) were commercial grades Licocene PEMA 4351 and PE 4201 provided by Clariant GmBH, Germany. Properties of these materials are provided in Table 1. The molecular weights data (Mw, Mn, MWD) was obtained by high temperature GPC at 135 C and was kindly provided by the manufacturer. Polyethylene standards were used for GPC calibration. The maleic anhydride (MA) content was measured by colorimetric titration. Diamine, EDR-176 was a commercial polyetherdiamine supplied by Huntsman Chemicals, USA. The diamine had a Mw of 176 g/mol, was supplied as a liquid and used as received. Antioxidant stabilizers Irgafos 168 and Irganox 1010 used were obtained from Ciba Specialty Chemicals, Basel, Switzerland. Solvents xylene and methanol were reagent grade and used as received.
[0000]
TABLE 1
Characterization of polyethylene waxes
M w
M n
M w /M n
MAH content 2
PE4201
—
—
—
0.0
PEMA4351
3000
1200
2.5
7.08
1 Measured by high temperature GPC at 135° C.
2 Measured by titrations
Reactions
[0045] All reactions were carried out in a 500 ml glass resin kettle equipped with a thermometer, drop bottle, condenser and an overhead stirrer. The impeller was a high-speed dispersion blade made of stainless steel. A stirrer bearing was used to ensure no solvent escapes the system. Controlled amounts of PEMA4351, vacuum dried overnight at 110° C., and xylene was added to the clean and dried resin kettle. Approx. 0.01% of antioxidant (AO) a 50/50 mixture of Igafos 168 and Irganox 1010 antioxidants was also added to protect the polymers against possible degradation at high temperatures. The condenser, thermometer, stirrer bearing and stirrer were then placed and the whole assembly was lowered in an oil bath maintained at 200° C. with a feedback controller. Stirring was maintained at 500 rpm for 10 min to ensure complete dissolution of polymer.
[0046] Controlled amounts of EDR-176 diamine were then added as a 40% v/v solution using the drop bottle in one shot. The stirrer speed was maintained above 400 rpm as circumstances permitted on addition of amine because of gelation of reaction mixture. The reaction time was 15 minutes unless the material gelled, in which case the reaction had to be terminated earlier. At the end of each reaction, the reaction contents were dropped in methanol to precipitate the polymeric products. The filtered products were dried overnight in fume hood, crushed in a blender with 0.01% of AO and then vacuum dried overnight at 110° C. to remove any trace amounts of solvent left over.
Titrations
[0047] The MA content of the PEMA4351 was determined by colorimetric titrations. 0.2 g of the sample was dissolved in 60 ml of Xylene under reflux. The hot solution was then titrated against a standard ˜0.01 KOH in methanol. The KOH solution was standardized against a standard HCl (0.01 N) solution. Thymol blue indicator in methanol was used to detect the end point. When the blue coloration did not change for a minute titration was stopped.
FTIR
[0048] Thin films of neat PEMA4351 and reaction products were obtained by compression molding at elevated temperatures in a mechanical press. FTIR spectra were collected using a BioRad© FTS 40 FTIR equipped with Win IR software for data collection and analysis. At least 16 scans were applied and data between 400 and 4000 cm −1 were recorded. The carbonyl absorption bands around 1792 and 1860 cm −1 were monitored to follow the extent of reaction. To account for the variation in thickness of the films, the peak at 720 cm −1 representing the methylene groups in the polymer backbone was used as the reference peak.
Rheological Measurements
[0049] Dynamic viscoelastic measurements were performed in Advanced Rheometrics Expansion System (ARES), a constant strain rheometer equipped with a transducer capable of measuring torque values ranging from 0.2-200 g-cm. In all measurements parallel plate geometry with 25 mm platens was used. Sample discs of 1.5 mm thickness were prepared by compression molding in a mechanical press to conduct rheological measurements. All measurements were carried out within the linear viscoelastic region established by a strain sweep. Dynamic time and frequency sweeps were performed at different temperatures using a hot air convection oven. Stress relaxation measurements were also performed to assess inhibition of material flow as a consequence of crosslinking of the reaction products.
Results and Discussion
Reactions
[0050] Evidence of the reaction between the maleic anhydride grafted PEMA4351 and diamine were evident as soon the amine was dropped in the solution containing grafted polymer. Frothing in the reaction mixture, and a decrease in the RPM of stirrer were observed. Table 2 summarizes the gelation observations during the reaction. Gel formation was observed to be a function of both reaction mixture concentration and NH 2 /MA molar ratio. No gelation was observed during the reaction time (15 min) in dilute (40 g/160 ml) systems irrespective of NH 2 /MA molar ratio used. In the concentrated system (60 g/120 ml) gelation occurred only when NH 2 /MA=1.0. For the very concentrated (60 g/60 ml) system gelation was observed at all NH 2 /MA values.
[0000]
TABLE 2
Summary of observations during the reactions
and sample preparation for characterization
Observation
Reaction
during
FTIR film
Disc
System
reaction
formation
formation
Dilute
0.5
No gelation
Yes
Yes
(40 g + 160
1.0
No gelation
Yes
No
ml)
1.5
No gelation
Yes
Yes
2.0
No gelation
Yes
Yes
Concentrated
0.5
No gelation
Yes
Yes
(60 g + 120
1.0
Gelled
No
No
ml)
instantaneously
1.5
No gelation
Yes
Yes
2.0
No gelation
Yes
Yes
Highly
0.5
Gelled
No
No
concentrated
instantaneously
(60 g + 60 ml)
1.0
Gelled
No
No
instantaneously
1.5
Gelled
No
No
instantaneously
2.0
Gelled
No
No
instantaneously
[0051] In order to analyze the extent of reaction achieved and property change in the reaction products by FTIR and rheological measurements, thin films and circular discs of the reaction products had to be prepared by compression molding at elevated temperatures. However, not all reaction products could be successfully made into thin films and discs. Once again Table 2 summarizes the results. With the exception of dilute system NH 2 /MA=1.0 where a film was achieved but no disc could be formed, agreement exists between the gel formation during the reaction and the unsuitability of the material to form disc. A closer look at these discs and films suggested inability of the grain/particles to fuse together (sinter) to form disc or film. This indicates that the material is crosslinked to a high degree and therefore does not sinter easily.
FTIR
[0052] FTIR was used to assess the extent of reaction. In order to use the FTIR results quantitatively, a calibration plot was generated. In the absence of calibration standards blends of maleic anhydride grafted PEMA4351 and ungrafted PE4201 were prepared in different compositions. The absorbance at 1860 and 1792 cm −1 associated with the carbonyl of maleic anhydride were recorded. The peak at 720 cm −1 assigned to the CH 2 groups in the PE backbone was taken as the reference peak. FIG. 1 a shows the FTIR spectra for the blends and pure PEMA4351 and PE4201. An increase in the absorbance at 1860 cm −1 and 1792 cm −1 is observed with the increase of maleic anhydride grafted material in the blend. The relative peak height (target peak/reference peak) at 1860 and 1792 cm −1 are plotted against blend composition in FIG. 1 b . A linear trend is observed between the relative peak heights and maleic anhydride concentration in the blend.
[0053] FIGS. 2 a and 2 b shows the FTIR spectra and relative peak height at 1860 and 1792 cm −1 plotted against the NH 2 /MA content in the reaction mixture for the concentrated (60 g/120 ml) system. The maleic anhydride peak gradually disappears with increasing NH 2 /MA ratio. At NH 2 /MA ratio of 1.5 and 2.0 no peak is observed suggesting complete reaction. The missing data at NH 2 /MA=1.0 is due to the fact that we were unable to form a film for FTIR analysis for this sample.
Rheological Measurements
[0054] Rheological measurements in the linear viscoelastic region were performed to assess the residual reactive species/degradation and changes in structure of the reactive polyolefin prepolymers (crosslinking). FIG. 3 a shows the time sweeps for materials recovered from the dilute solution experiments. Whereas, the reaction products at molar ratio NH 2 /MA=0.5 do not show any change in storage modulus (G′) over one hour at 140 C, a slight increase in G′ is observed for products when the molar ratio NH 2 /MA=1.5 and 2. This increase is more pronounced for material recovered from experiments in concentrated solution as seen in FIG. 3 b . These results suggest that some further reaction is taking place during the rheological measurements.
[0055] Results for the frequency sweeps at 140 C for the dilute and concentrated system are presented in FIGS. 4 a and 4 b respectively. No appreciable change in G′ was observed over almost three decades of frequency. This is typical behavior of crosslinked materials. The varying G′ plateau values of modulus for the systems investigated are likely associated with the varying degree of crosslinking achieved in each system. In materials recovered from both, the dilute and concentrated solution experiments, the maximum G′ is observed for NH 2 /MA=1.5 followed by NH 2 /MA=2.0 and 0.5 respectively.
[0056] To further assess the presence of crosslinking in the reaction products stress relaxation experiments were performed. In all cases a step strain of 5% which was within the linear viscoelastic range was applied and torque was monitored to know how the material relaxes. A low density polyethylene sample was also tested under similar conditions at 160 C was used as a reference uncrosslinked material. The results are presented in FIGS. 5 a and 5 b . Whereas, the torque values uncrosslinked LDPE dropped to almost zero within 100 seconds after the application of strain, torque values never approached zero even after half an hour. This is a typical behavior of crosslinked material. For all reaction products the torque leveled off at different values of equilibrium torque (τ e ) depending on the degree and nature of cross linking achieved.
Example 2
[0057] This above example illustrate that it is possible to produce thermosets of polyolefins by carrying out reactions between maleic anhydride functionalized olefin with polyetherdiamines in the solvent free melt state.
Experimental
Materials
[0058] Licocene PEMA4351 (maleic anhydride grafted polyethylene) was supplied by Clariant® Canada, Inc. With these materials maleic anhydride grafting is carried out in a batch process using a free radical mechanism as described in the patent literature [1]. The grafts are believed to be distributed randomly based on the free radical mechanism utilized to achieve them. PEMA4351 received as fine grains was vacuum dried overnight at 100° C. before use. Polyether diamine (ED600) was obtained from Huntsman Chemicals, USA. It is a liquid at room temperature and was used as received.
[0059] The polyether backbone constitutes predominantly polyethylene oxide units although some propylene oxide units are also present. The important characteristics of the materials are presented in Table 3. MW, viscosity and density values reported were obtained from the supplier. Titrations were performed in our lab.
[0000]
TABLE 3
Characteristics of materials
MAH
M w
M n
Viscosity
Density
content 3
g/mol
M w /M n
(mPa · s)
(g/cm 3 )
(%)
PEMA4351
3000
1200
2.5
300 1
—
5.20 (59.4 mg KOH/g)
ED600
—
600
—
75 2
1.035
—
1 measured at 140° C.;
2 measured at 140° C.
3 assessed by colorimetric titrations
Preparation of Reaction Products
[0060] Reactions were carried out in the melt at different NH 2 /MA molar ratios using either a melt blender or a resin kettle as described in Table 4. The melt blender used was a Haake PolyLab system. PEMA4351 was first added to a preheated mixing chamber (150° C.) and allowed to melt. Diamine was then added and mixing continued for 20 minutes at 150° C.
[0061] For reactions carried out in a resin kettle, controlled amounts of PEMA4351 and ED600 diamine were added to the clean, dried glass kettle at room temperature. The kettle was then placed in a heating mantle and the temperature was increased approximately linearly with time to about 150° C. with continuous stirring (1000 rpm) using an overhead stirrer while monitoring the temperature and rotational speed of the agitator. The reaction was continued until the reaction mixture exhibited the Weissenberg effect at which point the reaction mixture was removed from the resin kettle.
[0062] Samples recovered from the resin kettle or melt blender were further processed by compression molding the material using a hydraulic press and aluminum molds at different temperatures and length of time.
[0000]
TABLE 4
Reaction products preparation method
Products
Licocene-
diamine
NH 2 /MA
Method of preparation
0.66
Melt blender
PEMA4351
1.0
Melt blender
ED600
1.5
Resin kettle
2.0
Resin kettle
3.0
Resin kettle
Titrations
[0063] Approximately 0.2 g of the sample was dissolved in 60 ml of xylene under reflux in a 500 ml round bottom flask. Once the polymer was dissolved, the hot solution was titrated against standard KOH solution (˜0.02 M) prepared in methanol. Thymol blue dissolved in methanol was used as indicator. When the blue color persisted for one minute the titration was stopped and degree of grafting assessed as mg KOH/g of polymer. These values can be used to calculate the degree of maleic anhydride grafted using simple stoichiometric calculations provided elsewhere [5].
Gel Content
[0064] Measured amounts (approximately 0.2-0.3 g) of polymeric sample were cut into small pieces and enclosed in small pouches made of 120×120 mesh Type 304 stainless steel wire cloth. These pouches were then suspended in refluxing xylene for more than 12 hours according to ASTM D2765. Samples were removed from the solvent, washed with acetone and allowed to dry. The loss in weight was used to calculate the degree of gel content.
FTIR
[0065] FTIR spectra were generated using a Nicolet® 510 FTIR instrument. Thin films of the samples were prepared by compression molding in a mechanical or hydraulic press at elevated temperatures. Spectra were recorded between 400-4000 cm −1 . At least 32 scans were performed to generate a spectrum.
Results and Discussion
[0066] The materials recovered from reactive processing in the melt blender or the resin kettle exhibited physical manifestations that would indicate that some reaction had occurred. For example, a visual increase in viscosity and elasticity at the temperature of processing was evident.
[0067] Unexpectedly, measurement of the residual acid content by colorimetric titration shows that complete consumption of anhydride groups did not occur in the reaction product as reported by earlier studies [2-4]. These measurements are only representative of a portion of the reaction product for some of the samples because of incomplete dissolution of the reaction product. As shown in the Table 5 the residual maleic anhydride content in the reaction products from the melt blender are 1.89-2.16% (21-25 mg KOH/g) and are a bit higher in the products that were reaction processed in the resin kettle (˜2.7% (˜30 mg KOH/g)). Almost 50% of the initial maleic anhydride content 5.2% (60 mg KOH/g) is still unreacted.
[0000]
TABLE 5
Residual maleic anhydride in the reaction products
Residual acid
NH2/MA
content (mg
moalr ratio
KOH/g)
Dissolution observation
0.66
21.6 ± 1.9
Did not dissolve fully prior to titration
1.0
24.7 ± 1.4
Did not dissolve fully prior to titration
1.5
31.1 ± 0.5
Dissolved but precipitate out on titration
with methanolic KOH
2.0
30.6 ± 0.8
Dissolved but precipitate out on titration
with methanolic KOH
3.0
30.3 ± 1.0
Completely dissolved and no
precipitation on addition of methanolic
KOH
[0068] The titration data indicate that complete reaction has not occurred with the materials obtained from mixing in the melt blender and the resin kettle. These materials were further processed by compression molding the materials in aluminum molds at elevated temperatures of 160° C., 180° C. and 200° C.
[0069] The reaction products exhibited flow and completely filled the molds on application of pressure at elevated temperatures. This indicates that the reaction products are still thermoplastic and can be shaped by injection or compression molding. This is tremendously encouraging from the commercial application point of view.
[0070] Measurements of the gel content of samples that were processed at the different temperatures for different periods of time are presented in FIG. 6 . The data at zero minutes is the measured gel content for the materials recovered from the reactor. A value less than 1% indicates that little or no crosslinking is present in this material. The gel content in processed materials was observed to be quite different. Within 10 minutes of molding at 160° C. more than 30% of the material converted to insoluble gel. The degree of gelation was even higher at higher temperatures. The gel content of the processed materials was observed to be a function of both time and temperature. At all temperatures investigated more crosslinking was observed at longer processing times.
[0071] The increase in gel content as a result of high temperature processing confirms that coupling reactions continued during subsequent processing which results in more crosslinks and hence increased insoluble “gel” material. This phenomenon has not been previously reported for these types of systems.
[0072] FIG. 4 shows the anticipated crosslinking reactions in these type of systems [3, 4]. Spectroscopic measurements were used to follow the reaction chemistry in the compression molded samples as a function of processing history. Specifically, the emergence of the imide absorptions in the FTIR spectra at wavenumbers 1700 and 1770 cm-1 as well as amide responses at 1640 and 1550 cm −1 are evident in the FTIR spectra of which FIG. 8 is an example. It can clearly be seen that the relative imide absorptions are increasing with compression molding time.
[0073] Ratios of these imide and amide absorptions with a reference peak (methylene absorption at 720 cm-1) are plotted in FIG. 9 as a function of compression molding time at 180° C., for the reaction product produced using an NH 2 /MA mole ratio of 1.5. This data shows that the concentration of imide groups in increasing in the compression molded product as the material is processed for longer times. A decrease in the concentration of amide groups is also observed. This data is consistent with the change in gel content reported in FIG. 6 .
[0074] These examples demonstrate that the reaction products of maleated reactive olefin prepolymers with polyether diamines can be subsequently processed as one component thermosetting materials. This has not been previously reported for materials of this type. These reaction products have significant utility as molding compounds, coatings, adhesives and sealants, for example.
[0075] The ranges of polyamine in the cross linked thermoset product may be quite broad because it depends on polyamine molecular weight. At a given mole ratio of amine to anhydride, the weight fraction of low molecular weight polyamine will be significantly less than the corresponding weight fraction of polyamine needed when a higher molecular weight polyamine is used. The polyamine may be present in the thermoset material in a range from about 1% by wt to about 90% by wt depending on a molecular weight of the amine used and the amount of reactive functionality per weight of the polyolefin wax. In preferred thermoset materials the polyamine is present in the material in a range from about 25% by wt to about 75% by weight.
[0076] The present thermoset materials disclosed herein may include a mixture of more than one maleic anhydride functionalized reactive polyolefin wax and/or more than one type of polyamine. For example, in some applications it may be advantageous to use more than one type of polyamine, for example one may use a mixture of polyamines that includes difunctional and trifunctional materials in order to alter the properties of the thermoset. The use of combinations of multifunctional coreactants to achieve network polymers having a different degree and architecture of crosslinking is used in other thermosetting systems such as epoxies and urethanes and will be known to those skilled in the art.
[0077] Likewise, it can also be advantageous to use blends of functionalized polyolefin wax as a coreactant in order to alter or achieve different properties in the thermoset produced. For example, it might be advantages to blend functionalized polypropylene based waxes with functionalized polyethylene based waxes in order to alter the balance of properties of the thermoset produced. Advantage can also be had by blending waxes having different levels of concentration of functional groups, but homologous in olefin type to produce multiphase morphologies in the resulting thermoset.
[0078] While the current examples illustrate the production of polyolefin thermosets using maleic anhydride functionalized polyolefin wax as a starting material, it will be appreciated by those skilled in the art that low molecular weight polyolefin polymers that have been functionalized with carboxylic acid functionality can also be used to generate thermosetting materials in reactions with polyamines. In fact, hydrolysis of the maleic anhydride in maleic anhydride functionalized polyolefin wax yields carboxylic acid functionality which can also participate in reaction with amines. This hydrolysis is known to occur when maleic anhydride functionalized waxes are exposed to atmospheric moisture for extended periods of time, for example. It is common practice in commercial applications that use maleic anhydride functionalized polyolefin polymer to “dry” the polymer at elevated temperatures for some time in order to reverse this hydrolysis and regenerate the maleic anhydride. It is not surprising then that, melt reactions between acrylic acid functionalized polyolefin wax and polyamines will also yield thermosetting materials given conditions sufficient to drive the reaction. Thus, as used herein, the phrase “maleic anhydride functionalized reactive polyolefin wax” is meant to cover acrylic acid functionalized polyolefin waxes as well as the circumstance in which a polyolefin wax has been modified to functionalize the polyolefin with carboxylic acid groups or their salts.
[0079] The above examples illustrate that it is possible to produce thermosets of polyolefins by carrying out reactions between maleic anhydride functionalized olefin with polyetherdiamines in solution or in the solvent free melt state. An added benefit of carry out the reaction process in the melt state is that there is no need to recover the thermoset created from a solvent. The coreactants may be processed using techniques such as those employed for reaction injection molding (RIM) of polyurethane coreactants to produce molded articles without the need to use extrusion or extrusion based injection molding equipment.
[0080] Those skilled in the art will be aware that typical processing of polyurethane coreactants in a RIM process involves the use of pumps and mixing devices such as static mixers to stoichiometrically mix coreactants as they enter a mold to cure to produce articles of commerce. Two component reactive systems are used commercially for the production of molded articles, adhesives, sealants, coatings and other materials of commerce.
[0081] An additional advantage observed in the work here with these polyolefin prepolymer materials is that it is possible to combine coreactants in the melt without having a complete reaction ensue. This allows the combined materials to be processed as a one component reactive thermoplastic liquid that can be caused to convert to a thermosetting material be heating to elevated temperatures. One component heat-activated curable thermoplastics that convert to thermosetting materials upon heating can be used commercially to make one component molding compounds, adhesives, sealants, coatings and other materials of commerce.
[0082] While, in the above examples no attempt was made to influence the rate of production of thermoset material, those skilled in the art will recognize that the rate of thermoset production can be influenced by variation of the stoichiometry and/or additives. In these examples, it was observed that stoichiometries involving equimolar amine and carboxylic acid content achieved the gel point much more quickly than some other stoichiometries. It may also be possible to use additives (such as p-toluenesulfonic acid) that are known to acid catalyze the formation of amide or imide to influence the rate of reaction.
CONCLUSIONS
[0083] Reactions between maleic anhydride grafted reactive polyolefin waxes and polyamines were successfully carried out to generate crosslinked thermoset products. The observed reaction in terms of frothing, viscosity build up and gel formation seems to be fast. Gel (swelling of reaction mixture) was observed to be a function of reaction mixture concentration as well as the NH 2 /MA molar ratio. FTIR analysis was successfully carried out to assess the extent of reaction. Rheological measurements in the linear viscoelastic region (strain, time sweeps, dynamic frequency sweeps and stress relaxation) experiments suggest good conversion and presence of crosslink in the reaction product.
[0084] As used herein, the terms “comprises”, “comprising”, “including” and “includes” are to be construed as being inclusive and open-ended. Specifically, when used in this document, the terms “comprises”, “comprising”, “including”, “includes” and variations thereof, mean the specified features, steps or components are included in the described invention. These terms are not to be interpreted to exclude the presence of other features, steps or components.
[0085] The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.
REFERENCES
[0000]
1. Hohner G. U.S. Pat. No. 5,998,547 and Hohner G.; Bayer M. U.S. Pat. No. 7,005,224.
2. Orr, C. A.; Cernohous, J. J.; Guegan, P.; Hirao, A.; Jeon, H. K.; Macosko, C. W. Polymer 2001, 42, 8171-8178.
3. Lu, Q.-.; Macosko, C. W.; Horrion, J. J. Polym. Sci. Part A 2005, 43, 4217-4232.
4. Song, Z.; Baker, W. E. J. Polym. Sci. Part A 1992, 30, 1589-1600.
5. Gaylord, N. G.; Mehta, R.; Mohan, D. R.; Kumar, V. J Appl Polym Sci 1992, 44, 1941-1949.
6. Socrates, G. In Infrared and Raman characteristic group frequencies: tables and charts ; Wiley: Chichester; New York, 2000;, pp 347.
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The present invention provides a cross linked polyolefin thermoset material, comprising maleic anhydride functionalized reactive polyolefin wax cross linked with a polyamine. The thermoset may be made by a method involving reaction of a maleic anhydride functionalized reactive polyolefin wax with a polyamine. The polyolefin may be polyethylene, polypropylene and their copolymers. The polyamine is a primary or secondary alkyl polyamines, alkyl ether polyamines, aryl polyamines. Polyols may be used instead of polyamines, for example alkyl polyols, alkyl ether polyols or aryl polyols.
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BACKGROUND OF THE INVENTION
The present invention relates to a bobbin holder.
More particularly, this invention concerns bobbin holders in thread winding machines.
It is known in the art to provide an elongated support for a set of two or more bobbins and a number of cutting members equal to the number of bobbins. It is very essential that such cutting members do not interfere with either the withdrawal of the filled bobbins from the support or the installing of new empty bobbins on the support. This is especially important in applications where the process of winding the thread onto the bobbins must not be interrupted so that automatic thread transfer from a full bobbin to an empty one, and replacement of the full bobbin with another empty bobbin, must be employed.
An analogous arrangement, see for example German allowed application No. 24 55 116, includes a cutting member which is covered by a movable bobbin holder. To render such a construction possible it is necessary to provide the holder with a groove for receiving the cutting member and a spacer to prevent the cutting member from moving away from the holder. In order to cut the thread, the same has to be displaced inside the holder. Such a thread is subject to becoming slack when a drop of the speed of this thread takes place. Such slack disappears only when the thread tension subsequently increases again rapidly, so that the thread is pulled onto the cutters and tears off. As a result, one end of the thread, sometimes even a small loop, extends between the holder and the cutting element. During withdrawing of the bobbin from the holder this end of the thread can be caught and becomes untangled. Also, before installing a new empty bobbin torn-off thread pieces must be removed. Furthermore, in the prior art the thread is not cut but is torn off across the sharp edges of the cutting element.
SUMMARY OF THE INVENTION
It is a general object of the present invention to avoid the disadvantages of the prior art bobbin holders.
More particularly, it is an object of the present invention to provide a bobbin holder which has such a construction of the cutting element, that a thread to be cut slides along a sharp edge of the cutting element and is cut on the holder.
Another object of the present invention resides in providing such a cutting element on the bobbin holder as to insure that no end of thread can be caught between the holder.
In pursuance of these objects and others which will become apparent hereafter, one feature of the present invention resides in a provision of an elongated support and a set of at least two separable bobbins replaceably received on said support. The bobbins are subject to axial withdrawal from the support upon winding onto the bobbins of a predetermined amount of filamentary material (for example thread) to fill the bobbins.
The holder is further provided with means for cutting the filamentary material when a respective one of said bobbins has received said predetermined amount of filamentary material. These means are mounted on the support for movement relative to the latter between a rest position and a working position in which it is operable to cut said filamentary material.
The holder is provided with means for displacing the cutting means between said positions thereof in response to replacement of the filled bobbins with new empty bobbins.
The novel features which are considered as characteristic for the 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 DRAWING
FIG. 1 is a schematic front view of a bobbin holder in accordance with the present invention;
FIG. 2 is a plan view of the bobbin holder;
FIG. 3 is a view of two bobbins mounted on a support; and
FIG. 4 through FIG. 6 are sectional views of two filled bobbins in different positions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and first to FIG. 1 thereof, it may be seen that the reference numerals 1 and 2 designate two supports 1 and 2 of a bobbin holder which is rotatable about axis 3. The filled bobbin 4 of the support 2 is rotatable (as shown in FIG. 1) about the axis 3. Both supports 1 and 2 are driven separately. A thread 5 runs about an empty tube of the support 1 towards and onto the filled bobbin 4 of the support 2. In such a position the thread 5 will not be engaged by the thread layer 6 of a thread laying device 7 and a back-up roller 8 does not touch the tube of the support 1. As the diameter of the winding bobbin on the tube of the support increases, the complete thread laying arrangement 9 moves leftwardly as shown by the arrow.
FIG. 2 shows the moment at which the thread is transferred from the filled bobbin on the support 2 to the new empty bobbins on the support 1. A pneumatic piston 10 pivots gripping hooks 13 and 14 about axes 11 and 12 which are respectively located at the upper and underside of the support. As a result, the threads 5 are displaced to a position where it can be engaged by catching and cutting blades 15 and 15', respectively. The blades 15 and 15' catch the threads 5 and sever them so that they can be wound onto the empty bobbin tubes. The gripping hooks 13 and 14 pivot back from the area of the bobbins and return to the position shown in FIG. 2 by dotted lines. Then the bobbin holder rotates counterclockwise until the tube of the support 1 abuts the back-up roller 8 (see FIG. 1). In this position the thread 5 will be taken over from the thread layer 6. The process of replacement of the filled bobbins with new empty bobbins is now over.
Two tubes 16 and 16' are installed on the support 2. The catching-and cutting-blade 15 is fixedly mounted on the support 2. The swingable catching-and cutting-blade 15' is located between previously installed tubes 16 and 16'.
FIGS. 4 through 6 show the position and function of the swingable catching- and cutting-blade 15'. Inside the hollow support 2 there is provided a lever 17, which is pivotable about a pin 18. The lever has one end which is provided with a tool holder (i.e. adapter) 23 with the catching- and cutting-blade 15'. The other end of the lever 17 is provided with a flat spring 22. To pivot the lever 17 there is provided a compression spring 19. The spring 19 is so spaced from the pin 18 that when the tube 16' does not depress the end of the lever 17 then the other end of the lever 17 with the cutting blade 15' moves downwardly and the opposite end with the flat spring 22 moves upwardly. Throughgoing recesses 24 and 25 are provided in the wall of the support 2 for receiving the adapter 23 and the flat spring 22, respectively. In order to limit the displacement of the lever 17 there are provided end screws 20 and 21.
The adapter 23 is provided with a horizontal pushing pin 26, which during displacement of the tubes 16 and 16' from the support 2 pushes the tube 16 forward, so that the catching- and cutting-blade 15' will pivot downwardly. This is essential, in order to permit a releasing mechanism (not shown) to withdraw the filled bobbins 16 and 16' together from the support 2. The pin 26 is mounted on the adapter 23 below the cutting blade.
The pin 26 is a longitudinal body, which is provided with a leading end portion and a trailing end portion. The leading and trailing end portions have cross-sectional dimensions exceeding that of the body.
FIG. 5 shows the beginning of common withdrawal of the filled bobbins on the tubes 16 and 16'. Due to the displacement of the tube 16' the pushing pin 26 pushes the tube 16 so far rightwardly that the lever 17 with the adapter 23 pivots downwardly. In addition, the tube 16' presses against the tapered surface 27 of the adapter 23 and thus maintaining the downwardly pivoting of the adapter 23 with the cutting blade.
FIG. 6 shows a following step of the withdrawal. The lever 17 with the adapter 23 pivots so far downwardly that the bobbins can be withdrawn without any hindrance.
When new empty tubes are inserted into the support 2, they are moved until after the tube 16' abuts the end stop. The tube 16' presses the flat spring 22 downwardly and consequently the adapter 23 upwardly. Then, the tube 16 is installed on the support 2.
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 a bobbin holder.
While the invention has been illustrated and described as embodied in a bobbin holder, 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 of specific aspects of this invention.
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A bobbin holder, particularly in thread winding machines, comprises an elated support operative for replaceably receiving a set of separate bobbins. The bobbins are subject to axial withdrawal from the support upon winding onto the bobbins of a predetermined amount of thread. The holder is further provided with an element for cutting the thread when a bobbin is filled. This element is mounted on the support for movement relative to the latter between a rest position and a working position in which it is operable to cut the thread.
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FIELD OF THE INVENTION
The present invention relates to a system for monitoring equipment for measuring, controlling, and regulating and a corresponding method.
BACKGROUND INFORMATION
Known monitoring systems for measuring and control equipment allow for the system to enter a so-called secure state in response to a malfunction occurring. The secure state either causes the current operating state of the measuring and control equipment to change or prevents the operating state from being changed at a later time. One can then provide for, e.g. the measuring and control equipment, the system controlled by the measuring and control equipment, or the measuring and control equipment and the controlled system, being switched off in response to the occurrence of a malfunction.
A system for controlling and/or regulating an internal combustion engine is known from German Published patent Application No. 40 04 083. This includes several sensors, which generate signals that represent the operating parameters of the internal combustion engine. Malfunction detection is carried out, using these signals. The malfunction monitoring occurs within predefined sub-ranges having a lower sensitivity than outside of these predefined sub-ranges. If a malfunction is detected, then it can initially be checked if this can be attributed to impaired or incomplete signal transmission. The system is only switched off, when this is not the case. In this manner, the system is prevented from switching off in response to a malfunction of one of the sensors.
A disadvantage of the described system is that the system is immediately switched off in response to the occurrence of certain malfunctions. This indeed means that the safety of operation is high, but also that the availability is insufficient.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to propose a device and a method for monitoring measuring and control equipment, which ensure both ample operational safety and satisfactory availability.
The system of the present invention to monitor equipment for measuring, controlling, and regulating has a monitoring device, which monitors the method of functioning of the measuring and control equipment. In this context, malfunctions of the monitored measuring and control equipment are detected. In addition, the monitoring device may control the operating state of the equipment. The system distinguishes itself in that a counter having a count is provided, the detection of a malfunction increases the count, and the operating state of the measuring and control equipment is controlled as a function of the count.
A malfunction is indeed detected, but does not necessarily or directly result in the operating state of the measuring and control equipment being controlled, i.e. result in the measuring and control equipment possibly being switched off. Initially, the occurrence of a malfunction only leads to the count of the counter being increased. This only results in disconnection, when the count reaches a certain, predetermined value. This value is variable and represents the reaction threshold of the monitoring device. By selecting the reaction threshold, the user has the option of setting his system for monitoring with regard to operational safety and availability, in accordance with his requirements.
The monitoring device preferably monitors the method of functioning of the measuring and control equipment, using communications operations carried out at regular time intervals. Each communications operation, which includes an exchange of data between the monitoring device and the measuring and control equipment, yields either a malfunction or correct functioning. Therefore, the reaction time of the monitoring system may also be determined by the choice of intervals between the communications operations.
In a preferred, specific embodiment, the detection of correct functioning reduces the count of the counter. This prevents sporadically occurring malfunctions from resulting in the measuring and control equipment being switched off, since detected instances of correct functioning reduce the count again and again.
It is advantageous, when the count is to be controlled independently of the occurrence of malfunctions. This makes sense when the predetermined reaction threshold appears to be too high in some operating states. For example, the measuring and control system may keep the counter of the monitoring device just below the reaction threshold, using deliberate, false information. This holding of the counter is maintained for the duration of the special operating state that is critical with regard to safety. Consequently, the short reaction time from the occurrence of a fault to the reaction of the monitoring device provides the monitoring system with the maximum possible safety.
According to a particularly preferred specific embodiment of the system of the present invention, the count of the at least one counter is compared to a threshold value, a reset or a fault reaction being triggered in response to the threshold value being reached or exceeded. In practice, the monitoring of such a threshold value turns out to be simple and reliable.
A second counter level is advantageously defined below the threshold value, the count not being allowed to fall below the second counter level, and an artificially generated malfunction being input into the system in response to the second counter level being reached.
In this connection, it is conceivable for the reaction threshold or the threshold value to be adjustable or variable. This measure makes it possible to adjust to specific operating states.
The variation of this second counter level also allows the desired availability or reaction time of the system to be flexibly adjusted.
Therefore, depending on the situation, one may also select between maximum safety and maximum availability during continuous operation, with an arbitrary number of graduations.
According to a particularly preferred embodiment of the system of the present invention, a first fault counter assigned to the monitoring device and a second fault counter assigned to the equipment to be monitored are provided, which may be periodically checked and/or compared to each other in order to monitor the system. This measure allows the function of the equipment to be monitored to be checked, using the first counter, and allows the function of the monitoring device to be checked, using the second fault counter. A periodic comparison of the counts of these two fault counters also allows so-called sporadic faults to be detected in a simple manner, as will be explained later in the specification.
In this context, it is advantageous that the first fault counter may be used for counting an image of the second fault counter's count. Therefore, the so-called expected value of the second fault counter may be stored, using the first fault counter.
A third fault counter, which is used to compare the counts of the first and second fault counters, is advantageously provided.
The method of the present invention provides for a counter being used whose count is increased in response to detecting malfunctions, and for the control of the operating state of the monitored equipment being carried out as a function of the count.
The method of functioning of the measuring and control equipment is preferably executed, using communications operations performed in regular intervals. Each communications operation reveals either a malfunction or correct functioning.
It is advantageous, when correct functioning is registered by a reduction in the count of the counter. This ensures that sporadically occurring malfunctions also do not result in the operating state of the measuring and control equipment being influenced.
The count may advantageously be controlled independently of the occurrence of malfunctions. Thus, the reaction time of the monitoring system may be adapted to current requirements during continuous operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of a preferred specific embodiment of the monitoring system according to the present invention.
FIG. 2 shows a diagram for explaining a preferred specific embodiment of the method according to the present invention.
FIG. 3 shows a representation corresponding to FIG. 1 , of a further preferred embodiment of the monitoring system according to the present invention, the (schematic) representation of the internal combustion engine being dispensed with in this case.
FIG. 4 is a first diagram for explaining a possible time sequence of the method according to the present invention.
FIG. 5 is a second diagram for explaining a possible time sequence of the method according to the present invention.
DETAILED DESCRIPTION
FIG. 1 shows, in a schematic representation, a preferred specific embodiment of the monitoring system according to the present invention, in use. Shown is an internal combustion engine 1 , equipment 2 for measuring, controlling, and regulating (measuring and control equipment), a monitoring device 3 , and a counter 4 .
Internal combustion engine 1 is controlled with the aid of measuring and control equipment 2 . Measuring and control equipment 2 is in turn monitored by monitoring device 3 . This monitoring is accomplished by communications operations between monitoring device 3 and measuring and control equipment 2 . If a malfunction is detected, the count of counter 4 is increased. If correct functioning is registered, then the count is reduced. As soon as the count reaches a certain value, monitoring device 3 assumes a secure state. This results in measuring and control equipment 2 , and possibly internal combustion engine 1 as well, being switched off.
In a diagram, FIG. 2 explains the execution of a preferred specific embodiment of the method according to the present invention. The Roman numerals in the drawing represent the count.
The count is I in state 5 . After a certain time span, a communications operation occurs between monitoring device 3 and measuring and control equipment 2 . If a malfunction is meanwhile detected, then the count is increased to II, as is represented in state 6 . A further communications operation occurs again, after a certain time span. If a malfunction is detected, then the count is increased to III, which corresponds to state 7 . The count is otherwise reduced to I, which corresponds to state 5 . If the count is III, in accordance with state 7 , then the detection of correct functioning causes the count to be reduced to II, state 6 . If a malfunction is detected in state 7 , then the count is increased to IV, which corresponds to state 8 . A communications operation is repeated in state 8 . If this detects correct functioning, then the count decreases to III, i.e. state 7 . If a malfunction is detected in state 8 , then the count is increased to V, which corresponds to state 9 . This count causes monitoring system 3 to assume the secure state. As a result, measuring and control equipment 2 and internal combustion engine 1 are switched off. Therefore, a count of V represents the reaction threshold of the monitoring system for the exemplary embodiment shown.
According to a further preferred embodiment, the system and method of the present invention may be implemented, using a number of cooperating fault counters. This is described below in light of a function-computer monitoring module, using three fault counters: A first fault counter 4 is provided in monitoring module 3 of measuring and control equipment (function computer) 2 . A second fault counter 14 , which is a copy of fault counter 4 , is provided in measuring and control equipment 2 . The task of fault counter 4 is to count incorrect responses of measuring and control equipment 2 . Fault counter 14 in measuring and control equipment 2 is used to store the expected value of fault counter 4 . A further fault counter 24 , which counts inconsistencies between counters 4 and 14 , is advantageously provided in the measuring and control equipment.
The following strategy is, for example, applicable to the counters: For example, it is assumed that the operating state of measuring and control equipment 2 is controlled in response to the count value of fault counter 4 reaching 13. In the following, this is assumed to be a reset. One starts, for example, with a beginning count of 11, in order to prevent a defective measuring and control device from being activated after initialization. If a correct response, e.g. from measuring and control equipment 2 , reaches fault counter 4 , its count is reduced by 1 (this always occurs in the case of a correct response, if the count is greater than 0). If an incorrect response is detected, then three fault points are added. In the case in which a count greater than or equal to 13 is reached, a reset of the measuring and control equipment is triggered.
To check if monitoring module 3 is functioning correctly, measuring and control equipment 2 purposely sprinkles incorrect responses in at an appropriate count of fault counter 4 , in order to check if, and to what extent, monitoring module 3 detects incorrect responses and its fault counter 4 accordingly counts these responses correctly. Since, for example, the system only allows the measuring control equipment to detect the current count of counter 4 every 32nd inquiry-response communication (communications frame), fault counter 14 in the measuring and control equipment is used internally in the measuring control equipment to count a representation of fault counter 4 . Therefore, fault counter 14 contains the so-called expected value of fault counter 4 . If monitoring module 3 signals the count of its fault counter 4 in place of the 32nd inquiry in the cycle, then the measuring and control equipment compares the expected value, i.e. the count value of fault counter 14 , to the signaled value, i.e. the count value of fault counter 4 . If these two count values do not agree, then third fault counter 24 is increased by three points. If there is agreement, then the count value of fault counter 24 is decreased by 1.
Fault-tolerance times must continually be taken into consideration in systems for monitoring measuring and control equipment. In the exemplary embodiment described here, the monitoring plan is hierarchically constructed in three levels, the first level being formed by measuring and control equipment 2 , which is monitored by the second level, an internal software check test not represented in detail. The third level, which is essentially monitored by monitoring module 3 , is used to monitor the second level, i.e. the hardware, which is used to carry out the software monitoring.
If, according to a first case constellation, a fault occurs on the first level, i.e. in the measuring and control device, then the tolerance time is a function of the reaction speed of the second level, i.e. of the internal software monitoring, which advantageously has direct access to the output stages of the measuring and control equipment.
Such an access path via a computer pin typically carries the name of “PEN” (=Power ENable) and switches, for example, the actuator system of a connected motor to high resistance.
An example of another case is the occurrence of a fault in the computer hardware (measuring and control hardware), which means that the fault has to be detected via the third level.
A hardware fault results in an incorrect response of the measuring and control equipment. In this case, monitoring module 3 detects the incorrect response and repeats, for example, the inquiry that was responded to incorrectly, until the response is correct. If, in this connection, fault counter 4 exceeds its reaction threshold before the inquiry is responded to correctly, then monitoring module 3 triggers a reset of measuring and control equipment 2 . The fault-tolerance time now depends on how many false responses must be received in order for fault counter 4 to exceed the reaction threshold. When the fault counter has a count of 0, then, for example, five incorrect responses must be received in succession, in order to exceed the threshold of 13 selected for purposes of illustration. In the case in which each inquiry-response communication typically lasts 40 ms, the result here is a monitoring-module reaction time of approximately 200 ms.
Since a representation of fault counter 4 is logged in the measuring and control equipment, using fault counter 14 , fault counter 4 may be influenced by deliberate, incorrect responses, in order to keep it closer to the reaction threshold. However, this brings an unknown variable to the forefront, namely the occurrence of so-called “sporadic faults”. These are faults, which occur randomly due to effects that are mostly external, and are unpredictable. The monitoring module detects an incorrect response and advances its fault counter 4 . Of course, these faults may not be logged in the expected value of counter 14 , since the measuring and control equipment assumes that the response was transmitted correctly. These discrepancies are discovered when fault counter 4 signals back in place of every 32nd inquiry, and they result in an increase in the count of counter 24 .
Rare faults that occur sporadically should not lead to a reset of the system, when this adversely affects the user. Of course, this condition limits the possibilities of decreasing the fault-tolerance time, using the “level control” of the fault counter in the measuring and control equipment. However, frequent, sporadic faults should not lead to a reset, EMC-contaminated, high voltage lines being named here as an example, and these high voltage lines not being able to ensure safe operation.
The stipulation, that a rare, sporadic fault should not result in an immediate reset of the system, is explained by way of example: This means that counter 4 is allowed to reach a maximum count of 10, in spite of the incorrect responses that are sprinkled in: Fault counter=10—>correct response—>fault counter=9—>correct response—>fault counter=8—>correct response—>fault counter=7—>deliberately incorrect response—>fault counter=10—>. . .
The occurrence of a sporadic fault increases the count of counter 4 by three points, i.e. this would result in a count of 13. In the case of a fault count of 7, the maximum time leading up to a reaction is the duration of three incorrect responses, i.e. 3×40 ms=120 ms.
Since the counter 14 in the measuring and control equipment may only be adjusted to the true count of the counter 4 in monitoring module 3 after every 32nd communications frame, only a sporadic fault may occur within this time, since this uses up the reserve for this time frame. Therefore, sporadic faults may only occur at a minimum interval of 31 frames=31×40 ms=1.24 s. Otherwise, they trigger an (unwanted) reset. If two sporadic faults are permissible within a time of 1.24 s, the maximum tolerance time that occurs increases to 160 ms (admissibility of an additional incorrect response). To assess the frequency of sporadic faults occurring, it is necessary to conduct trials in the real system.
In order to reduce the risk of a reset due to sporadic faults, the “level control” of the count of counter 4 may be implemented as a function of the driving situation. The manner, in which the “counter level” is controlled most effectively, depends on various boundary conditions (required tolerance time, required fault sensitivity, etc.) and must be tested in the real system, as well.
It should be pointed out that, in monitoring module 3 , the RAM test may be designed as a writability test, so that a so-called “sleeping fault” may be formed. If a bit inverter produces too low a value in fault counter 4 , then the strategy of “level control” may fail.
In a third case, the communication may break down for unknown or arbitrary reasons, so that monitoring module 3 detects the response after, e.g. a 10.51 ms timeout, switches off the output stages of the measuring and control device, and triggers a reset. In the worst case, even the time for posing an inquiry, e.g. 100 ms, must be included, so that in the worst case, one must expect a delay time of 20.51 ms.
The method according to the present invention is explained once more by way of example, using the graphs of FIGS. 4 and 5 .
In these graphs, the x axis represents the time (subdivided into individual cycles), and the y axis represents the count of counter 4 .
Drawn into FIG. 4 are 3 special counter readings, which will be explained in detail. Count 13 is a threshold value, which may not be exceeded. In the case in which this threshold value is exceeded, the result is a reset or a fault reaction of the system or the count. A counter level A is drawn in at count 7 , and a counter level B is drawn in at count 1 . This should make clear that, according to a preferred specific embodiment of the method of the present invention, a second counter level located below the threshold value is variable. According to the specific embodiment represented in FIG. 4 , counter level B (count 1 ) is active, i.e. the count may decrease to a value of 1, before an incorrect response that is artificially sprinkled in increases the count by a value of 3 (see arrow P). In the case of a threshold value of 13 and a possible, lower count of 1, it is apparent that up to 4 faults may be tolerated without a fault reaction occurring or the system resetting. When these parameters are set, the system has a high availability and high tolerance, and at the same time, a relatively long reaction time. In the exemplary embodiment of FIG. 4 , the typical reaction time R is 4 cycles. For example, 4 fault occurrences are represented by high-voltage flashes, whose occurrence at a time t F results in a reset (not shown), since the threshold value is exceeded at point y(t F ).
Using FIG. 5 , it is now explained how a shorter reaction time may be attained.
According to the specific embodiment of FIG. 5 , it can be seen that the counter level A having a count of 7 is active. In other words, a decrease in the count below the value of 7 is not permitted. Consequently, this specific embodiment typically tolerates just one fault, before a fault reaction results from threshold value 13 being reached. In this case, reaction time R is only two cycles. For purposes of illustration, high-voltage flashes and points t F and y(t F ) are once again shown.
Finally, it should be pointed out that it would also be possible to make the threshold value variable. In this case, one could also dispense with varying the lower counter level.
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Described is a system and a method to monitor measuring and control equipment. The occurrence of a malfunction does not immediately lead to the monitoring system entering a secure state, but rather increases the count of a counter. If the count exceeds a certain value, then the monitoring system enters a secure state.
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FIELD OF THE INVENTION
The present invention relates to a device for damping pressure surges in a fluid. The device has a housing and a piston displaceable longitudinally against the pretensioning force of a spring-type accumulator.
BACKGROUND OF THE INVENTION
Devices for damping pressure surges include hydraulic accumulators. One of the main functions of hydraulic accumulators is to receive specified volumes of a pressurized fluid of a hydraulic system and to return them to the system as required. Since the fluid is pressurized, hydraulic accumulators are treated as pressure vessels and must be designed to withstand the maximum operating pressure as determined by the approval standard. For volume equalization in the hydraulic accumulator and as a result the associated storage of energy, the pressurized fluid in the hydraulic accumulator is subjected to the force exerted by a weight, spring, or gas. Equilibrium always prevails between the pressure of the pressurized fluid and the opposing pressure generated by the force of the spring or by the gas. In most hydraulic systems, use is made of hydropneumatic accumulators, that is, ones subjected to the action of a gas and having a separating element. A distinction is made between bladder, piston-type, and diaphragm accumulators.
These hydropneumatic accumulators perform a wide variety of functions in a hydraulic system. For example, in addition to performing the energy storage function referred to, they may be called upon to contribute to absorption of mechanical shocks and to surge damping in hydraulic systems. Pulsations occur in the flow volume especially when hydraulic pumps such as positive-displacement pumps are employed. Such pulsations cause vibrations as well as noise, and may result in damage to the hydraulic system as a whole.
The hydraulic pumps in question, positive-displacement pumps in particular, are also employed in so-called common-rail technology in the area of diesel engines. Recent third-generation developments add piezo technology for injection systems for diesel fuel. The recently developed piezo inline injectors for the third common-rail generation (cf. VDI-Nachrichten [Association of German Engineers-News], No. 33, Aug. 15, 2003) use piezo actor modules, which act by coupler modules on switching valves. The switching valves in turn act on an injector module of the fuel injection system. The outstanding hydraulic rapidity of the system results from the high degree of integration of the inline injector, that is, from the nearness of the piezo package to the valve needle in the tip of the injector. In comparison to the previous generation, the mass moved was reduced in the new systems from 16 g to 4 g. The mass moved is understood to mean the mass of the valve needle and the fuel with which the control space is filled. The respective technical configuration requires very high system pressures, ones reaching the order of magnitude of 2200 bar. The respective system pressure is to be built up by the hydraulic pump indicated, in particular a positive-displacement pump. The build-up is attended by the disadvantages described of pressure and pulsation surges. If the pressure surges are transmitted to the injector system, this transmission may result in critical states of the system and in failure of the piezo injector system with the injection system. If, as is known in the state of the art (see DE 195 39 885 A1), conventional hydraulic accumulators with separating elements (pistons) are included in the diesel fluid system as outlined in the foregoing. They nevertheless encounter their limits in view of the high system pressures indicated of up to 2200 bar.
DE 101 48 220 A1 discloses another device for damping pressure pulsations in a fluid system, especially in a fluid system of an internal combustion engine. The device disclosed comprises a housing in which at least one operating space is present. This space is connected to the fluid system and is limited in area by at least one movable wall element in the form of a metal diaphragm mounted on the edge side in the housing so as to be stationary. This wall element is functionally connected to a first spring unit. To provide the possibility of smoothing out pressure pulsations in the fluid system even with variable pressure present, provision is made such that the device comprises at least a second movable wall element which delimits a second operating space and which has a metal diaphragm fastened on the edge side in the housing. The first spring unit is mounted between the two wall elements in the form of diaphragms and is functionally connected to both. A throttle unit is also provided by which the second operating space is connected to the fluid system. The pressure pulsations in a fluid system may be reliably and efficiently smoothed out with different pressure levels present. However, because of the stationary clamping of the wall elements (diaphragms) their movability is restricted, so that functional safety in operation may be endangered at high pressures and correspondingly large pulsation and pressure surges.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a device for damping pressure surges permitting, even with very high system pressures produced by a hydraulic pump, a diesel fuel pump in particular, ones as high as 2200 bar, damping and/or smoothing out such pressure surges so that there is no harmful introduction of power into a piezo injector system of common-rail technology.
This object is attained by a device having one piston that operates in conjunction with another piston that is be guided so as to be displaceable longitudinally in a connecting piece of the housing. In operation of the device, the one piston exerts a compressive force on the other piston in every displaced position of the latter. Very high-frequency pressure surges may be controlled in the diesel fuel system. Yet, operation remains safe, even if due to the hydraulic pump in the form of the diesel fuel pump very high system pressures of up to 2200 bar and higher are produced. As a result of mechanical uncoupling of the two pistons and the constant application of the compressive force by one piston on the other, any pressure surges introduced are reliably intercepted and controlled. In particular, the uncoupling of the pistons ensures that any leakage accompanied by leakage flows, are kept small or controlled so that operational failures are prevented in the system as a whole. Preferably, one piston is of a diameter several times greater than the diameter of the other piston. An unimpeded actuation process may be achieved with such pistons. Processes of canting of the other piston in the connecting piece of the housing in particular are prevented by separate, independent control of this piston.
In one preferred embodiment of the device of the present invention, the other piston is configured as a stamp and is controlled by at least one anti-loss device in a through opening in the housing of the connecting piece. Free displaceability of the respective piston between specified displaceability limits in the housing configuration is thereby achieved.
In another preferred configuration of the device of the present invention, the other piston is machined to the highest degree on the external circumference side. In particular, the other piston is lapped, so that a metal-sealed gap is obtained at least between parts of the external circumference and the other piston on the inner wall of the opening in the housing. In another configuration of the sealing system, the other piston may be provided with annular or lubrication grooves on the external circumference side. As a result, despite the high pressures of up to 2200 bar and above in the diesel fluid system, reliable sealing of the other piston from the interior of the housing with the first piston is achieved. Especially when annular or lubricating grooves on the external circumference of the other piston are used, a fluid seal may be built up which works against entry of fluid into the gap in the metal.
If, in another preferred embodiment of the device of the present invention, a leakage opening configured in the housing communicates with the fluid space between the pistons, diesel medium which succeeds in penetrating the interior of the housing may nevertheless be transferred free of pressure in the block as a sort of return flow for oil leakage in the direction of the tank or leakage side.
With respect to the very high pressures indicated, it has been found to be advantageous to provide as a spring-type accumulator at least one helical spring configured as pressure spring and/or a pressure gas. Use of a pure pressure gas may entail the disadvantage that, in view of the very high pressures, a process of liquefaction of the gas will take place in the housing area as a result of compression of the piston first indicated. However, as an alternative or in addition, the system pressures indicated may be reliably controlled by use of a pressure spring as the spring-type accumulator.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawing, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure:
FIG. 1 is a diagrammatic, side elevational view in section of a device for damping pressure surges, according to embodiments of the present invention, not drawn to scale, with two different cover element embodiments.
DETAILED DESCRIPTION OF THE INVENTION
The illustrated device performs the function of damping pressure surges in a fluid, in particular one in the form of diesel fuel. The device has a cylindrical housing 10 and has a piston 14 which may be displaced longitudinally against the initial pretensioning force of a spring-type accumulator 12 . The respective piston is configured as a cylindrical contact plate and is guided along its external circumference by a slip and/or sealing ring 16 along the cylindrical interior circumference or surface 18 of the housing 10 . The piston 14 accordingly has on its opposite sides two essentially level or planar contact surfaces 20 , 22 . For the purpose of guiding the spring-type accumulator 12 , the piston 14 is provided on the side facing accumulator 12 , with a cylindrical guide surface 22 . Guide surface 22 also rests against the inner surface 18 of the housing 10 on the guide surface outer circumference side.
The first piston 14 operates in conjunction with another or second piston 24 . The other piston 24 may be guided to be longitudinally displaceable in a connecting piece 26 of the housing 10 . As the illustration shows, the piston 14 furthermore operates in the housing by applying the compressive force to the other piston 24 , in every displaced operating position, including its front end contact position as shown, in operation or use of the device. The connecting piece 26 narrows in stages toward the free end of the housing 10 and is provided on the outer circumference side with a connecting thread 28 by means of which the housing 10 in the configuration illustrated may be connected to a fluid system, such as the diesel supply line for an injector system by the common rail technology. The housing 10 is positioned in a connecting line which leads to a hydraulic pump, a positive-displacement pump in particular, for example, one in the form of a diesel fuel pump or the like. The pressure surges occurring in operation of the diesel fuel pump, which may be considerable, with system pressures of up to 2200 bar or higher, are damped and smoothed out by the device of the present invention. Even high-frequency fluid surges are to be evened out. In addition, the damping device of the present invention is independently effective within prescribed limits even in the event of very high pressure amplitudes.
The respective connecting piece 26 undergoes transition to a bottom 30 of the housing 10 , which bottom is strengthened lengthwise. The pistons 14 , 24 and the spring-type accumulator 12 are oriented longitudinally along the longitudinal axis 32 of the housing 10 and connecting piece 26 . In addition, the diameter of the piston 14 is several times greater than the diameter of the other piston 24 , so that very good impact force is introduced between the other piston 24 and first piston 14 , in view of the change in the relative diameters.
The other piston 24 is configured as a stamp or push rod and is guided in the through opening in the housing 36 of the connecting piece 26 , and is retained therein by at least one anti-loss device 34 in the form of a retaining ring. The anti-loss device 34 in particular can be a retaining ring, the front of which seals the housing opening 36 from the exterior and the projecting length of which comes in contact with the front end of the other piston 24 when the other piston is in its front limit position. When the other piston 24 is not in operation, its length has been determined so that the piston remains at a short axial distance, with slight clearance, from the anti-loss device 34 . However, as soon as a specified pressure level has been built up by the fuel, the clearance is eliminated. When the device is in the respective state of operation or use, the piston 14 applies a compressive force to the other piston 24 in any displaced position of the latter. In order to obtain good sealing, the other piston 24 undergoes the highest degree of precision machining on the external circumference side, in particular is lapped, so that a metal-sealed gap 38 is obtained at least between parts of the external circumference of the other piston 24 and the interior wall of the housing opening 36 . The other piston 24 has annular or lubricating grooves 40 for the purpose of further improvement in the sealing system. A labyrinth seal is thus obtained, one which makes it difficult for the diesel fuel to penetrate through the housing opening 36 into the clearance space 42 inside the housing 10 between the contact surface 20 and the facing surface 44 of the bottom 30 .
The fluid or clearance space 42 between the pistons 14 and 24 communicates with a leakage opening 46 in the form of a bore in the housing 10 . Consequently, an intentionally provided gap or leakage flow may be evacuated by the sealing system in the form of annular or lubricating grooves 40 , the metal gap 38 , and the clearance space 42 by the leakage opening 46 to the pressure-free leakage or tank side of the overall system. A sealing system 48 , such as one in the form of a conventional radial seal ring, is provided as an additional sealing system in the front area of the bottom 30 . When the housing 10 has been screwed into place, sealing, especially in the form of the leakage opening 46 , from the overall hydraulic or fluid system (diesel line network) may accordingly be effected by the connecting piece 26 with its connecting thread 28 .
A pressure spring in the form of a helical spring in this instance serves as a spring-type accumulator 12 . Pressure gas, such as gas in the form of nitrogen, may be applied in addition to the interior of the housing. The respective pressure spring 12 extends between the piston 14 and a cover element 50 . The cover element 50 may be in the form of a retaining plate 52 , and is retained in the housing 10 by safety means, a retaining ring 54 in particular. An alternative embodiment is presented in the figure in square framing. In this instance, the cover element 50 is a screw cap 56 screwed onto the housing 10 by external threading 58 on the external circumference side of such housing 10 .
The device of the present invention makes certain that any leakage flow which may occur may be reliably controlled and that the separate piston configuration of the pistons 14 and 24 ensures that canting does not occur. Pressure surges of very high frequency, in particular which affect the stamp-like additional piston 24 , may be transmitted at the same frequency as surges to the piston 14 , which then effects pulsation damping or smoothing by reacting on the other piston 24 . The system illustrated may be applied cost-effectively and produced by simple production technology with conventional steel materials, on the housing 10 side in particular. This device may generally be employed where low volumes under high pressure are to have the level damped or are to be displaced. Because of the surface relationships of the pistons, the spring to be employed may be made smaller, since the force required is correspondingly reduced.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
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A device for damping pressure surges in a fluid with a housing ( 10 ) and a piston ( 14 ) that can be longitudinally displaced inside the housing ( 10 ) against the pretensioning force of a spring energy store ( 12 ). The piston ( 14 ) interacts with another piston ( 24 ), which is guided in a connecting piece ( 26 ) of the housing ( 10 ) in a manner that enables it to be longitudinally displaced. During the operation of the device, the piston ( 14 ) exerts a pressure force onto the other piston ( 24 ) when the other piston is in any displacement position. Even pressure surges occurring with a high frequency can be reliably controlled in a functionally reliable manner.
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FIELD OF THE INVENTION
This invention is related to the field of the biotechnology and in particular with new recombinant antibodies obtained using genetic engineering technology, specifically with a chimeric antibody, a humanized antibody and a single chain Fv fragment obtained from murine ior C5 antibody, which recognize epitopes expressed in ior C2 antigen which has been characterised as glycoprotein complex which is expressed in normal and malignant colorectal cells.
BACKGROUND OF THE INVENTION
They have been tested different forms of colorectal carcinoma treatment, however up to day the surgery it has been the only curative way. The surgery has allowed reaching higher percents of survival, when the detection of the tumour is in an early stage, but unfortunately the most cases are diagnosticated when the tumour has metastized.
In this moment, the strategy to increase survival includes the diagnosis, the therapeutic and epidemiology, in stages wherein it has not been produced the dissemination of the disease to external layers of the organs and the tumour is still surgically curable. In the way, the knowledge of epidemiological factors as well as the development of new therapeutically methods will help to increase the survival.
The use of monoclonal antibodies (Mabs) or their fragments, labelled with radioactive isotopes for the detection of cancer through immunogammagraphic methods, has been used in the last years. The Mabs have shown potential to be used as carriers of radioisotopes and to be targeted to the associated tumour antigens.
Some of the radiolabelled antibodies have been used to detect tumours associated with carcinoembrionary antigens (CEA). The antibodies against CEA, labelled with I-131 or I-125 are used to detect tumours producing CEA or associated with this marker (U.S. Pat. No. 3,663,684, U.S. Pat. No. 3,867,363 y U.S. Pat. No. 3,927,193). Also, Mabs can be labelled with Tc-99m to get molecules for “in vivo” diagnosis.
The development of the hybridoma antibody technique by Köhler and Milstein revolutionised the discipline of immunochemistry and provided a new family of reagents with potential applications in the research and clinical diagnosis of diseases (Köhler G; Milstein C. (1975) Nature 256, 495-497). These antibodies have not shown strong therapeutic efficacy, while it has become routine to produce mouse monoclonal antibodies (mAbs) for use in basic research and clinical diagnosis, it has been difficult to use these for “in vivo” immunotherapy, because they have reduced half life in humans, poor recognition of mouse antibodies effector domains by the human immune system and also because foreign immunoglobulins can elicit an antiglobulin response (HAMA response) that may interfere with therapy.
The development of the genetic engineering has revolutionised the ability to genetically manipulate antibody genes and then to produce mAbs having decreased or eliminated antigenicity and enhanced desired effector functions, when these antibodies are used in the treatment or diagnosis of some pathologies. These manipulations have provided an alternative where a murine mAb can be converted to a predominantly human form with the same antigen binding properties (Morrison S. L; et al 1984, P.N.A.S. USA, 81,6851-6855).
Recently they have been developed some methods in order to humanise murine or rat antibodies and decrease xenogenic response against foreign proteins when they are used in humans.
One of the first intents to reduce antigenicity, has been by producing “chimeric” antibodies. In these molecules, the variable domains were inserted into human frameworks, in this way not only it can be reached the decrease of the immunogenicity but also the improvement of effector functions, because they are humans and therefore recognised by the immune system (Morrison S. L et al (1984) P.N.A.S, USA 81, 6851-6855). These chimeric molecules retain the recognition of the original antigen and its constant region is not immunogenic, although the immunogenicity against murine variable region is retained.
Other authors have attempted to build rodent antigens binding sites directly into human antibodies by transplanting only the antigen binding site, rather than the entire variable domain, from a murine antibody (Jones P. T et al (1986) Nature 321, 522-524, Verhoeyen M et al (1988) Science 239, 1534-1536). They have been developed some applications of this method by Rietchmann (Rietchmann L. et al (1988) Nature 332, 323-327; Quee C. et al (1989) P.N.A.S USA 86,10029-10033), however other authors have worked with reshaped antibodies, which included some murine residues in human FRs in order to recover the affinity for the original antigen (Tempest, P. R (1991) Biotechnology 9, 266-272).
Mateo et al. (U.S. Pat. No. 5,712,120) described a procedure to reduce immunogenicity of the murine antibodies. In this procedure, the modifications are restricted to the variable domains and specifically to the murine frameworks of the chimeric antibodies. Even more, these modifications are only carried out in the FRs regions with amphipatic helix structure, therefore are potential epitopes recognised by T cells. The method proposes to substitute the murine residues inside the amphipatic regions, by the amino acids in the same positions in the human immunoglobulines, of course the amino acids involved in the tridimentional structure of the binding site, it means Verniers zone, canonical structures of the CDRs and the amino acid of the inter-phase between light and heavy chain are excluded.
The antibody modified by the method described by Mateo et al, retains the capacity of the recognition and binding to the antigen, that recognised the original antibody and it results less immunogenic because of this it is got an increase of the therapeutic efficacy. Through this procedure only few mutations are necessary to obtain modified antibodies that shown reduced immunogenicity compared with chimeric antibodies.
The IOR C5 murine monoclonal antibody (patent application WO 97/33916) is an IgG1 isotype, obtained from immunisation of Balb/c with SW1116 cells (colorectal adenocarcinoma), recognised an antigen expressed preferentially in the surface and cytoplasm of the malignant and normal colorectal cells. This antibody does not recognise neither CEA, Lewis a, Lewis b, asialylated Lewis, membranes of normal mononuclear cells antigens nor red globules (Vazquez A. M. et al, Hybridoma 11, pag. 245-256, 1992).
Western blotting studies using SW1116 membranes extract showed that this antibody recognized a glycoprotein complex which was denominated ior C2, with two molecular weight forms (145 and 190 Kda) (Vázquez A. M. et al, Year Immunol. Basel, Karger, vol. 7, pag. 137-145,1993).
Also it is known from the state of the art that using genetic engineering techniques, recombinant fragments can be constructed from monoclonal antibodies. There are many reports validating the use of different antibody fragments in the “in vivo” diagnosis and the therapeutic of the diseases.
Ira Pastan et al. (EP 0796334 A1) describes the construction of single chain Fv fragments, using variables regions of antibodies that specifically recognised carbohydrates related with Lewis Y antigen. Using these fragments, he developed a method to detect cells bearing this antigen. Also, he gives evidences of the inhibitor effect of these fragments on cells bearing the antigen.
DISCLOSURE OF THE INVENTION
This invention is related to recombinant antibodies obtained using genetic engineering technology, specifically with a chimeric antibody, a humanised antibody and a single chain Fv fragment obtained from murine antibody IOR C5 antibody, produced by the hybridoma of the same name deposited in correspondence with the Budapest Treaty under accession number ECCC 97061101 with European Collection of Cell Cultures, on Jun. 11, 1997. This antibody recognizes epitopes expressed in ior C2 antigen, which is a glycoprotein complex that it is expressed in normal and malignant colorectal cells.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : Shows the genetic construction of the plasmid pPACIB.9plus, which is a modified plasmid to express fusion proteins in the cytoplasm of E. coli . This plasmid contains regulatory sequences to get the following functions: Promoter sequence (tryptophan), 27aa fragment derived from IL-2h for getting efficient expression of the protein and, a domain of 6 histidines codified in mature protein's C-terminal to be used during the purification of this protein.
DETAILED DESCRIPTION OF THE INVENTION
cDNA Synthesis and Gene Amplification of the Variable Region of Murine C5.
Cytoplasmic RNA was extracted from about 106 hybridoma cells of the monoclonal antibody C5 (Vázquez A. M. et al. Year Immunol, Basel, Karger, vol 7, pag. 137-145, 1993). The method used to extract RNA was described by Faloro et al (Faloro, J., Treisman, R., and Kemen, R. (1989). Methods in Enzymology 65:718-749).
The cDNA synthesis reaction consisted of 5 ug RNA, obtained with 25 pmoles of the designed primers to hybridise in the beginning of the constant region of murine IgG1, and in the murine constant kappa region for the light chain, 2.5 mM each of deoxinucleotide (dNTPs), 50 mM Tris-Hcl pH 7.5, 75 mM KCl, 10 mM DTT, 8 mM MgCl2 and 15 u of ribonuclease inhibitor (RNA guard, Pharmacia) in a total volume of 50 ul. Samples were heated at 700 C, for 10 min and slowly cooled to 370 C over a period of 30 min. Then, 100 units reverse transcriptase were added and the incubation at 420 C continued for 1 hour.
The variable regions of light chain (VK) and heavy chain VH) were amplified using Polymerase Chain Reaction (PCR). Briefly, 5 μl cDNA of VH or VK were mixed with 25 pmoles of specific primers, 2.5 mM each of dNTP, 5 μl buffer 10× for the enzyme DNA polymerase and 1 unit of this enzyme. Samples were subjected to 25 thermal cycles at 940 C, 30 sec; 500 C, 30 sec; 720 C, 1 min; and a last incubation for 5 min at 720 C.
Cloning and Sequencing of Amplified cDNA.
The purified VH and VK cDNA were cloned into TA vector (TA Cloning kit. Promega, USA). Clones were sequenced by the dideoxy method using T7 DNA Pol (Pharmacia, Sweden).
Construction of Chimeric Genes.
The light and heavy chains variable regions were obtained by enzyme restrictions from TA vectors and cloned into expression vectors (Coloma M. J. et al., Journal of Immunological Methods, 152, 89-104,1992).
The VH genes were cut from TA vector by EcoRV and NheI digestion, and cloned in PAH 4604 expression vector, an human constant IgG1 is included and histidinol resistance gene.
The resultant construction is C5VH-PAH4604. The VK genes were cut from TA EcoRV and SalI digestion and cloned In PAG4622. This vector contains resistance to the gpt and used kappa human constant region. The resultant construction is C5VK-PAG4622.
Chimeric Antibody Expression.
NSO cells were electroporated with 10 μg of C5VH-PAH4604 and 10 ug of C5VK-PAG4622 and linearized by digestion with Pvul. The DNAs were mixed together, ethanol precipitated and dissolved in 25 μl water. Approximately 107 NSO cells were grown to semiconfluency, harvested by centrifugation and resuspended in 0.5 ml DMEN together with the digested DNA in an electroporation cuvette. After 5 minutes on ice, the cells were given a pulse of 170 volts and 960° F.) and left in ice for a further 30 minutes. The cells were then put Into 20 ml DMEN plus 10% foetal calf serum and allowed recovering for 48 hours. At this time the cells were distributed into a 96-well plate and selective medium applied (DMEN, 10% foetal calf serum, 0,8 μg/ml mycophenolic acid, 250 μg/ml xanthine). Transfected clones were visible with the naked eyes 10 days later.
The presence of the human antibody in the medium of wells containing transfected clones was measured by ELISA. Microtiter plate wells were coated with goat anti-human (gamma chain specific, After washing with PBST (phosphate buffered saline containing 0.02% Tween 20, pH 7.5), 100 μl of culture medium from the wells containing transfectants was added to each microtitter well for 1 hour at 370 C. The wells were washed with PBST and the conjugated goat anti-human Kappa, light chain specific were added and incubated at room temperature for one hour. The wells were then washed with PBST and substrate buffer containing dietanolamine added. After 30 minutes the absorbency at 405 nm was measured.
Construction of Humanised IOR C5H by T Epitopes Humanisation.
Prediction of T Epitopes.
The variable region sequences of IOR C5 were analysed using AMPHI program, which predicts segments of the sequences 7 or 11 amino acids in length with an amphipatic helix, which are related with T immunogenicity. Also it was used SOHHA program which predicts hydrophobic helix (Elliot et al. J. Immunol. 138: 2949-2952, (1987). These algorithms predict fragments related with T epitopes presentation in the light and heavy variable regions of the IOR C5.
Analysis of Homology of Variable Regions.
The variable domains of IOR C5 are compared with those corresponding human variable domains, to identify the most homological human sequence with murine molecule. The human sequence databases used were reported in Gene Bank and EMBL, both of them available in Internet. The comparison was made by an automated-computerised method, PC-DOS HIBIO PROSIS 06-00, Hitachi.
Analysis for Immunogenicity Reduction.
The essence of this method lies in reducing the immunogenicity by humanisation of the possible T cell epitopes, with only few mutations in the FRs, specifically in the amphipatic helix, excluded the positions involved with the tridimentional structure of the binding site.
In this method it is compared VH and VK regions of the murine immunoglobuline, with the most homological human immunoglobuline sequence and it could be possible to identify the different residues between murine and human sequences, only inside the amphipatic regions, within the FRs zone (Kabat E.(1991) Sequences of proteins of immunological interest, Fifth Edition, National Institute of Health), only these murine residues will be mutated by those of the human sequence at the same position.
Those residues in the mouse framework responsible for the canonical structures or those involved in the Vernier zone can not be mutate, because they could have a significant effect on the tertiary structure and to affect the binding site. Additional information about the substitutions in the tertiary structure, could be obtain, doing a tridimensional molecular model of the variable regions.
Cloning and Expression of Humanised IOR C5 Antibody into NSO Cells.
After doing PCR overlapping to get mutations and humanised VH and VK, the obtained genetic construction corresponding to IOR C5 by humanisation of T cell epitopes, were cloned into expression vectors in a similar way as used for the expression of the chimeric antibody, yielding the following plasmids: C5Vkhu-PAG4622 and C5Vhhu-PAH4604. The transfection of these genes into NSO cells was done in exactly the same conditions that we previously described for the chimeric antibody.
Obtainment of Single Chain Fv Fragment. Construction and Expression of the scFv.
The strategy includes a first amplification using PCR, which modify VH and VL sequences, including the endonucleases restriction sites to clone in the expression vectors. The amplification used designed oligonucleotides on the exact sequence.
After amplifying, the variable regions are purified and digested with the corresponding restriction enzymes. The DNA fragments are purified and ligated to the expression vectors. Later, these genetic constructions are expressed in E. coli , following conventional methods.
In the extraction process of the protein from the producer cells, a rupture process by ultrasound is doing, and it is possible to separate the soluble and insoluble fractions combining SDS polyacrylamide electrophoresis gels, nitro-cellulose transfer and western blot.
Partial purification of the protein is carried out by a process which includes: (1) separation of the soluble and insoluble material by ultrasound and centrifugation, (2) Wash in low molarities of urea and solubilization in high concentrations of urea. From solubilized material, to purify the protein by affinity chromatography to metals ions. Later, the protein is renaturalised against buffer.
EXAMPLES
Example 1
Obtainment of the Chimeric Monoclonal Antibody
The VH and VK cDNAs were obtained from RNA extracted from the hybridoma producing the monoclonal antibody IOR C5 using reverse transcriptase enzyme. The specific primers used were:
For VH:
5′-aggtctagaa ctctccacac acaggagagc cagtggatag α-3′ [SEQ. ID. NO.15]
For VK:
5′-gcgtctagaa ctggatggtg ggaagatgg-3′ [SEQ. ID. NO.16].
The ADNc of the chains VH and VK were amplified using polymerase chain reaction (PCR) with Taq polymerase enzyme, and using specific primers ECORV/NHEI restriction site for VH and ECORV/SALI for VK. The specific primers used were:
For VH:
Oligonucleotide 1:
5′-ggggatatcc accatggctg tcttggggct gctcttct-3′ [SEQ. ID. NO.17]
Oligonucleotide 2:
5′-tgggtcgaca tgatgggggc tgttgtgcta gctgaggaga c-3′ [SEQ. ID. NO.18]
For VK:
Oligonucleotide 1:
5′-ggggatatcc accatgaggg tccccatgac tcagcttct-3′ [SEQ. ID. NO.19]
Oligonucleotide 2:
5′-agcgtcgact tacgttttga tttccagact tgtgtccc-3′ [SEQ. ID. NO. 20].
The PCR products were cloned in TA vector (TA cloning kit, Invitrogen). Twelve independent clones were sequenced by dideoxy method using T7 DNA Pol (Pharmacia). The VH and VK sequences have high relation with the sub-group 2 of Kabat.
Then, VH chain was digested ECORV/NHEI and VK, ECORWSALI, and cloned in PAH4604 and PAG4622 for VH and VK respectively. These vectors were donated by Sherie Morrison (UCLA, California, USA), and they are used for the immunoglobulines expression in mammalian cells. The PAH 4604 vector has included human constant region IgG1 and the PAG 4622 has human Ck (Novel vectors for the expression of antibody molecules using variable regions generated by polymerase chain reaction., M. Josefina Coloma et al, Journal of Immunological Methods, 152 (1992), 89-104) The resultant constructions after clonig IOR C5 regions were VHC5—PAH4604 and VKC5-PAG4622.
NSO cells were electroporated with 10 ug of the chimeric vector C5VH-PAH4604 and 10 ug of C5VK-PAG4622 and linearized by digestion with Pvul. The DNAs were mixed together, ethanol precipitated and dissolved in 25 ul water. Approximately 107 NSO cells were grown to semi-confluence, harvested by centrifugation and resuspended in 0.5 ml DMEN together with the digested DNA in an electroporation cuvette. After 5 minutes on ice, the cells were given a pulse of 170 volts and 960 uF and left in ice for a further 30 minutes. The cells were then put into 20 ml DMEN plus 10% foetal calf serum and allowed to recover for 48 hours. At this time the cells were distributed into a 96-well plates and selective medium applied (DMEN, 10% foetal calf serum, 10 mM histidinol). Transfected clones were visible with the naked eyes 10 days later.
The presence of chimeric antibody in the medium of wells containing transfected clones was measured by ELISA. Microtiter plate wells were coated with goat anti-human (gamma chain specific, Sara lab). After washing with PBST (phosphate buffered saline containing 0.02% Tween 20, pH 7.5), 20 ul of culture medium from the wells containing transfectants were added to each microtitter well for 1 hour at 370 C. The wells were washed with PBST and alkaline phosphatase conjugated goat anti-human Kappa, light chain specific were added and Incubated at room temperature for one hour. The wells were then washed with PBST and substrate buffer containing dietanolamine added. After 30 minutes the absorbance at 405 nm was measured.
Example 2
Obtainment of Different Versions of Humanised Antibody
The VH and VK IOR C5 sequences were compared with a human sequences database, obtaining the most human homological sequence with the IOR C5.
Then the amphipatic regions or possible T cell epitopes, were determined in VH and VK regions.
For VH, mutations were introduced in positions 10 and 17, and the amino acids ASP and SER by GLY and THR respectively, were substituted. These mutations were done by PCR overlapping, using primers 1 and 2, 3 and 4 in a first PCR and the results of these PCR were overlapped in a second PCR, using 2 and 4 primers, whose sequences are the following: (Kamman, M., Laufs, J., Schell, J., Gronemborg, B. Rapid insertional mutagenesis of DNA by polymerase chain reaction (PCR). Nucleic Acids Research 17:5404,1989).
Primers for the mutations 10 and 17 of the heavy chain.
Primer 1:
5′-gagtcaggac ctggcctggt gaaaccttct cagacacttt cactcacc-3′ [SEQ. ID. NO. 21]
Primer 2:
5′-tgggtcgaca tgatgggggc tgttgtgcta gctgaagaga c-3′ [SEQ. ID. NO. 22]
Primer 3:
5′-ggtgagtgaa agtgtctgag aaggtttcac caggccaggt cctgactc-3′ [SEQ. ID. NO. 23]
Primer 4:
5′-ggggatatcc accatggctg tcttggggct gctcttct-3′ [SEQ. ID. NO. 24].
After the former mutations were verified by sequencing, new mutations were introduced to this mutated DNA, the new mutations introduced in positions 43 and 44 were LYS and GLY, substituting ASN and LYS respectively. The overlapping procedure was done as the previous overlapping. The mutations were verified by sequencing, this new construction was called C5VHhu.
The primers described for these mutations were:
Primers for the mutations 43 and 44 in the heavy chain.
Primer 1:
5′-cagtttccag gaaaaggact ggaatggatg-3′ [SEQ. ID. NO. 25]
Primer 2:
5′-tgggtcgaca tgatgggggc tgttgtgcta gctgaagaga c-3′ [SEQ. ID. NO. 26]
Primer 3:
5′-catccattcc agtccttttc ctggaaactg-3′ [SEQ. ID. NO. 27]
Primer 4:
5′-ggggatatcc accatggctg tcttggggct gctcttct-3′ [SEQ. ID. NO. 28].
For VK the mutations were done in positions 15, 45 y 63 substituting ILE, LYS and THR, by LEU, ARG y SER, respectively.
The mutations were introduced by overlapping PCR as describe previously. The sequences of the used primers are shown. The new genetic construction was named C5Vkhu.
Primers for the mutation 15 of the light chain.
Primer 1:
5′-ttgtcggtta cccttggaca accagcc-3′ [SEQ. ID. NO. 29]
Primer 2:
5′-agcgtcgact tacgttttga tttccagact tgtgtccc-3′ [SEQ. ID. NO. 30]
Primer 3:
5′-ggctggttgt ccaagggtaa ccgacaa-3′ [SEQ. ID. NO. 31]
Primer 4:
5′-ggggatatcc accatgaggg tccccatgac tcagcttctc ttggt-3′ [SEQ. ID. NO. 32]
Primers for the mutation 45 of the light chain.
Primer 1:
5′-ggccagtctc caaggcgcct aatctat-3′ [SEQ. ID. NO. 33]
Primer 2:
5′-agcgtogact tacgttttga tttccagact tgtgtccc-3′ [SEQ. ID. NO. 34]
Primer 3:
5′-atagattagg cgccttggag actggcc-3′ [SEQ. ID. NO. 35]
Primer 4:
5′-ggggatatcc accatgaggg tccccatgac tcagcttctc ttggt-3′ [SEQ. ID. NO. 36]
Primers for the mutation 63 of the light chain.
Primer 1:
5′-cctgacagat tcagtggcag tggatca-3′ [SEQ. ID. NO. 37]
Primer 2:
5′-agcgtcgact tacgttttga tttccagact tgtgtccc-3′ [SEQ. ID. NO. 38]
Primer 3:
5′-tgatccactg ccactgaatc tgtcagg-3′ [SEQ. ID. NO. 39]
Primer 4:
5′-ggggatatcc accatgaggg tccccatgac tcagcttctc ttggt-3′ [SEQ. ID. NO. 40]
All the mutations were verified by sequence.
The humanised VK and VH were cloned into the vectors PAG4622 and PAH4604, the followings constructions were obtained, C5Vkhu-PAG4622 and C5VHhu-PAH4604.
The NSO cells were electroporated with 10 μg of the humanised C5VHhu-PAH4604 and 10 μg of the C5VKhu-PAG4622. These vectors were linearized with PVUI digestion.
The electroporation and detection of the clones expressing humanised antibody IOR C5h were identical to the previous described for the chimeric antibody.
Example 3
Construction of the Single Chain Fv Fragment
Construction of the scFv fragment (VH-linker-VL), from variable domains (VH y VL) of IORC5 mAb. Cloning into expression vector to express in E. Coli.
Procedure (a). Construction of the scFv.
The strategy has a first round of amplification by PCR, modifying sequenced VH and VL regions, including restriction endonucleases sites to cloning into the expression vectors pPACIB.7plus and pPACIB.9plus. In the amplification, the oligonucleotides designed under the exact sequence are used.
Heavy Chain:
4066: EcoRV-FR1-VH
5′-gggatatctg aggtgcagct tcaggagtca gga-3′ [SEQ. ID. NO. 41]
4255: EcoRV-FR4-VH
5-caggatatcg cagagacagt gaccagagtc α-3′ [SEQ. ID. NO. 42]
Light Chain:
2938: Sal I-FR1-VL
5′-cgtcgacgat atccagatga caccagaact acc-3′ [SEQ. ID. NO. 43]
2935: Apa I-FR4-VL
5′-atgggccctt ttcatgtctc cagcttggt-3′ [SEQ. ID. NO. 44].
After amplifying the regions, were purified and digested VH (EcoRV) and VL (SalI-ApaI). The DNA fragments were purified and ligated with pPACIB.9plus and pPACIB.7plus, vectors, previously digested with restriction enzymes.
The plasmid pPACIB.7plus is modified to export to periplasm heterologous proteins whose genes are expressed in E. coli . This plasmid contains regulatory sequences to get the following functions: Promoter sequence (tryptophan), sequence for signal peptide (OMPA), sequence for linker peptide (Chaudhary et al., 1990) and a domain composed by 6 hystidines codified in matures protein's C-terminal to help in the purification of this protein (Gavilondo, J. V. et al. Proceedings of the IV Annual Conference on Antibody Engineering. IBC Conferences Inc. Coronado, Calif. Dec. 8-10, 1993).
The plasmid pPACIB.9plus ( FIG. 1 ) is modified to express in the cytoplasm heterologous proteins whose genes are expressed in E. coli . This plasmid contains regulatory sequences to get the following functions: Promoter sequence (tryptophan), 27aa fragment derived from IL-2h for getting efficient expression of the protein, and a domain of 6 hystidines codified in matures protein's C-terminal to help in the posterior purification of this protein (Gavilondo, J. V. et al. Proceedings of the IV Annual Conference on Antibody Engineering. IBC Conferences Inc. Coronado, Calif. Dec. 8-10, 1993).
The PCR reaction's product was used to transform the competent E. coli cells (strain MC1061), which were plated under solid selective medium and grown at 37° C. To select recombinant vectors, a bacterial colonies were inoculated in liquid medium and extracted plasmid DNA from this culture (Molecular Cloning, A Laboratory Manual, second edition, 1989, Sambrook, Fritsch and Maniatis). The plasmid DNA was digested by EcoRV, SalI/ApaI, XhoI/ApaI according cloning step, after applying under agarose gel and visualised with UV light, the recombinant clones were select between the clones with digestion pattern of two bands, one of them corresponding to pPACIB.7 and 9plus (approx. 2.9 kb), and the second to the expected domain (approx. 320 pb VH or VL y 720 pb for the scFv). For VH domain the insertion orientation was checked by DNA sequencing.
Procedure (b). Expression of scFv in E. Coli , Obtained from Variable Domain Genes of IOR C5 Mab.
Four strains of E. coli were transformed (TG1, coliB, W3110 y MM294), to study the cloned gene expression, using two recombinant plasmids selected in (a). Basically the recombinant bacteria were grown in liquid medium (LB) with ampicillin, overnight at 37° C. From these cultures, were inoculated fresh cultures containing ampicillin, and incubated by 3 hrs at 37° C. Then, the expression of the protein was induced, adding to the culture beta-indolacrylic acid (inductor of the tryptophan promoter). The analysis of the samples in SDS poliacryilamide gels at 12%, indicated that a protein of approximately of 28 kDa is expressed under these conditions, in the periplasmatic fraction for the construction of pPACIB.7plus and a 30 kDa band for the recombinant clone in pPACIB.9plus, which is expressed in TG1 in between 6-11% of the total bacterial protein. It demonstrated through a Western blot (Molecular Cloning, A Laboratory Manual, second edition de 1989, by Sambrook, Fritsch and Maniatis) with an antisera obtained in rabbit against Fab fragment of IOR C5 Mab, and immunopurified, that this protein corresponds to scFv of IOR C5.
Example 4
Obtention of the scFv from Bacterial Cultures, Renaturalisation and Recognition Assays to Antigen
Procedure (a). Extraction and Renaturalisation of the scFv of IOR C5 from Recombinant Clone in pPACIB.9plus.
In the extraction process of the protein from the producer cells using rupture ultrasound process, that allowed to separate soluble and insoluble fractions, combining with SDS-polyacrilamide electrophoresis gels, transferred to nitro-cellulose and Western blot, evidenced that the protein remains in the insoluble bacterial fraction.
Under these circumstances the protein was partially purified in a process including the followings steps:
(1) separation of the soluble and insoluble material by ultrasound and centrifugation, (2) wash in low molarities of urea (2 M) and (3) solubilization to high molarities of Urea (6 M).
From the solubilized material, the protein is purified in affinity chromatography to metallic ions and renaturalised against buffer solution.
Procedure (b). Binding Assay to Tumour Cells of the scFv-IORC5 Fragment.
Cell Lines:
The cells were obtained from Centro de Immunologla Molecular. SW948 adenocarcinome cell line was grown in L-15 medium supplemented with 10% bovine foetal serum at 37° C. in 6% CO 2 . Rai cell line (Burkift human limphome) and Hut 78 (T human cell line) were used as negative controls.
These cell lines were grown in RPMI 1629 supplemented with 10% bovine foetal serum at 37° C.
The cell suspensions were fixed to 106 cell/ml in PBS containing 1% albumin of bovine serum. 10 ul of cell suspension was added to each well. The slides were dried in the dusty free air during 3 hours and fixed in acetone-methanol (1:1) solution, 5 minutes, and hydrated in TBS by 10 minutes. Finally, the cells were processed, using immunocytochemistry assay.
The activity of scFv IORC5 fragment was determined using immunocytochemistry assay, trough immunoperoxidase technique. The cells were incubated during 2 hours at 37° C. with single chain Fv IOR C5, followed by incubation with anti Fab serum and with an anti-mouse peroxidase conjugated (HRP0), each one for 30 minutes at room temperature. The localisation site of the peroxidase were visualised with solution which contains 5 mg of 3-3 diaminobencidine, 5 ml of TBS and 5 μl of H2O2, 30%. Between incubations, the slides were washed with cold TBS.
After introducing in water, the slides were contrasted with Hematoxilline of Mayer and Canadian Balsam was added. Each experiment included positive and negative controls.
The immunocytochemistry studies revealed that this fragment is only positive to SW948 cell line, that showed a moderate labelled comparing with the complete Mab, demonstrated a specific recognition of the scFv IORc5 to this cell line. The label was associated to the membrane and cytoplasm compartment in the malignant colon cells.
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Novel recombinant antibodies from murine antibody IOR C5 produced by the hybridoma deposited with the ECCC 97061101. The recombinant antibodies were obtained using recombinant DNA technology and are characterized in that they recognize antigen ior C2. The recombinant antibodies are specifically chimeric antibody, humanized antibody, and single chain Fv fragment. The chimeric antibody contains the variable domains of the murine immunoglobuline and the constant regions of the human immunoglobuline. The humanized antibody contains the constant regions of human immunoglobuline and has been specifically modified in the murine frameworks regions (FRs) and within the latter, in those areas that may result in an antigenic site for cells T. The Fv fragment contains the variable domains of murine immunoglobuline. The invention also relates to the utilization of recombinant antibodies derived from murine antibody ior C5 in the diagnosis and therapy of colorectal tumors, the metastasis thereof and recurrences.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a composition comprising a Stauntonia Hexaphylla extract and use of the Stauntonia Hexaphylla extract.
[0003] 2. Description of the Related Art
[0004] An inflammatory response is an immune response which locally occurs, when cells or tissues are damaged or broken due to various causes, for example, exposure to harmful substances or organic systems including external infectious agents such as bacteria, fungi, viruses or a variety of allergens, so that the damage is minimized and damaged sites are restored to an original state.
[0005] In addition, various causes inducing inflammation include physical causes such as trauma, burns, frostbite and radioactivity, chemical causes such as chemicals, for example acids, and immunological causes such as antibody response. Furthermore, inflammation may be caused by imbalance of vessels or hormones.
[0006] The inflammatory response is a defense mechanism which is useful for protecting biological systems and removing substances produced by tissue damage, and involves symptoms including enzymatic activation caused by inflammation-mediators and immunocytes present in local vessels or body fluids, secretion of inflammation-mediators, infiltration of body fluids, cell migration, tissue destruction, erythema, edema, fever, pain or the like. Such symptoms may cause dysfunction.
[0007] In a normal case, inflammation functions to remove external infectious agents or neutralize or remove disease factors and to regenerate damaged tissues and thereby to restore normal structures and functions through an in vivo inflammatory response. However, as antigens are not continuously removed or inflammation becomes serious over a predetermined level or chronic due to specific endogenous substances, diseases such as hypersensitiveness or chronic inflammation may disadvantageously propagate. Inflammatory response is found in most clinical diseases and enzymes involved in inflammatory response are known to play an important role in carcinogenesis. In addition, inflammation is an obstacle in the course of treatment such as blood transfusion, medication or organ transplantation.
[0008] An inflammatory response is involved in various biochemical events in vivo. In particular, inflammatory response is initiated or controlled by inflammatory response-associated enzymes produced by immunocytes.
[0009] As has recently been revealed, progression of in vivo inflammatory response is known to be involved in enzymatic activities of cyclooxygenase (COX). The COX enzyme is a main enzyme involved in biosynthesis of prostaglandin present in biological systems. Two iso-enzymes, i.e., COX-1 and COX-2, are known. COX-1 exists in tissues such as stomach or kidney and is responsible for maintenance of normal homeostasis. On the other hand, COX-2 is temporarily and rapidly expressed in cells by mitogens or cytokines upon inflammation or other immune responses.
[0010] Another potent inflammation mediator, nitric oxide (NO), is synthesized from L-arginine through NO synthetase (NOS) and is produced in various types of cells in response to exterior stress such as UV light, or substances such as endotoxins or cytokines. Such inflammation stimuli increase expression of inducible NOS (iNOS) in cells and induce production of NO in cells through iNOS, thus activating macrophage cells and resulting in inflammatory response.
[0011] Accordingly, research associated with substances inhibiting production of NO is recently underway for efficient alleviation of inflammation. However, anti-inflammatory substances developed through such research have several side effects. For example, nonsteroidal anti-inflammatory drugs used in the treatment of acute inflammatory diseases or chronic inflammatory diseases are known to inhibit both COX-2 enzymes and COX-1 enzymes and thus cause side effects such as gastrointestinal disorders.
[0012] Meanwhile, cosmetics are routinely used to protect the skin and realize beautification and cleanliness. However, cosmetic compositions utilize ingredients indispensable for formation of cosmetic products which are inconsistent with skin protection application. For example, the ingredients include surfactants, preservatives, flavorings, UV blockers, pigments and various ingredients to impart other efficacies and effects. The ingredients necessarily used for production of cosmetics are known to cause side effects, such as inflammation, pimples or edema, to the skin.
[0013] In addition, serum and sweat secreted from the body, and fatty acids, higher alcohols and proteins as cosmetic components are decomposed to highly toxic substances by resident flora present in the skin, thus inducing skin inflammation. It is well-known that UV light emitted from the sun may also induce skin inflammation.
[0014] As such, factors causing skin side effects are always potential in cosmetics and a variety of research has been made to solve the factors. Substances used to date to alleviate irritation such as erythema or edema and inflammation include non-steroid substances such as flufenamic acid, ibuprofen, benzydamine and indomethacin, steroid substances such as prednisolone and dexamethasone. Allantoin, azulene, ε-aminocaproic acid, hydrocortisone, licorice acid and derivatives thereof (β-glycyrrhizinic acid, glycyrrhizinic acid derivatives) are known to be effective in anti-inflammation.
[0015] However, indomethacin, generally used as an anti-inflammatory agent, is unsuitable for use in cosmetics, hydrocortisone has a limited dose, licorice acid and derivatives thereof do not provide substantial effects due to limited concentration upon practical application caused by difficulty in stabilization or poor solubility. Use of most anti-inflammatory agents known to date is limited due to problems in terms of skin safety or stability upon cosmetic mixing.
[0016] In addition, mechanisms of therapeutic agents associated with gastritis are primarily associated with H2-blockers which block the second histamine receptor (H2 receptor) to reduce secretion of gastric acid from parietal cells. The reduced gastric acid prevents additional damage of damaged parietal cells (such as gastric ulcers). Such H2-blockers disturb metabolisms of other drugs, that is, potent inhibitors of P-450 in the liver, and thus require attention when administered in combination with other drugs. H2-blockers may cause side effects such as gynecomastia, impotence and hypoactive sexual desire disorder may occur in men due to exhibit anti-androgen effects. In addition, H2-blockers pass through the placenta and cerebrovascular barriers, thus causing more dangerous side effects to pregnant women or the elderly, and resulting in headache, confusion, stupor or dizziness.
[0017] Accordingly, there is a need for substances which are derived from natural substances, efficiently inhibit production of NO, inhibit expression of iNOS and TNF-a, efficiently inhibit activities of COX-2 enzymes, exhibit excellent anti-inflammatory effects, and have little or no side effects or cytotoxicity and thus have almost no limit in terms of content because they are derived from natural substances.
[0018] In particular, at present, research and development associated with anti-inflammatory drugs as natural medicines using natural ingredients, or cosmetics or cosmetic components using natural ingredients in order to satisfy consumer demands are actively underway.
[0019] In addition, an anti-pyretic drug is a medicine which acts to lower fever, elevated body temperature, and is also referred to as an anti-pyretic and analgesic drug because it generally acts to alleviate both fever and pain.
[0020] Currently believed hypothesis regarding action mechanism associated with the anti-pyretic drug is that the anti-pyretic drug inhibits biosynthesis of prostaglandin (PG) and thereby alleviates fever and realizes anti-pyretic action.
[0021] Specifically, upon fever, prostaglandin levels in thermoregulatory centers of the hypothalamus increase. For this reason, fever activity is inhibited and anti-pyretic effect is thus obtained by reducing prostaglandin levels in the thermoregulatory centers. In addition, prostaglandin is a known pain-inducing mediator. However, a variety of mechanisms associated with fever symptoms have been suggested.
[0022] Currently prescribed anti-pyretic drugs include salicylic acid derivatives such as aspirin, aniline derivatives such as acetanilide and phenacetin, and pyrazolone derivatives such as antipyrine, aminopyrine or sulpyrine. In addition, among anti-inflammatory drugs, there are non-steroidal anti-inflammatory drugs having anti-pyretic and analgesic actions such as indomethacin.
[0023] As described above, correlation between anti-pyretic and analgesic actions and anti-inflammatory effects, that is, inflammation-alleviating effects, is often found. However, some drugs have no almost anti-inflammatory action, but have potent anti-pyretic action, whereas other drugs have almost no anti-pyretic action, but have potent anti-inflammatory effects. Therefore, anti-inflammatory effect is determined to be not necessarily directly related to anti-pyretic and analgesic effects.
[0024] Accordingly, there is a need for development of substances which are derived from natural substances, not chemicals causing problems involved in various side effects, such as aniline agents causing acute intoxication, exhibit superior anti-pyretic action and have almost no risk of the side effects or cytotoxicity because they are derived from natural substances.
[0025] In particular, at present, research and development associated with anti-inflammatory drugs as natural medicines using natural ingredients in order to satisfy consumer demands are actively underway.
SUMMARY OF THE INVENTION
[0026] Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide an anti-inflammatory composition, as an active ingredient, containing a plant extract which has a low probability of occurrence of problems associated with side effects.
[0027] It is another object of the present invention to provide an anti-pyretic composition containing, as an active ingredient, a plant extract which has a low probability of occurrence of problems associated with side effects.
[0028] In accordance with the present invention, the above and other objects can be accomplished by the provision of an anti-inflammatory composition comprising a Stauntonia Hexaphylla extract as an active ingredient. The anti-inflammatory composition may be a medical composition, for example, an anti-pyretic and analgesic drug. In addition, the anti-inflammatory composition may be provided as an active ingredient of a cosmetic composition for inhibiting inflammation.
[0029] In another aspect of the present invention, provided is an anti-inflammatory drug comprising a Stauntonia Hexaphylla extract as an active ingredient.
[0030] In another aspect of the present invention, provided is a cosmetic composition for relieving or alleviating inflammation, comprising a Stauntonia Hexaphylla extract as an active ingredient.
[0031] In another aspect of the present invention, provided is an anti-pyretic composition comprising a Stauntonia Hexaphylla extract as an active ingredient. The anti-pyretic composition may be a medical composition, for example, an anti-pyretic drug or an anti-pyretic and analgesic drug.
[0032] During research associated with naturally-derived anti-inflammation, the inventors of the present invention found that a Stauntonia Hexaphylla extract exhibits superior anti-inflammatory effects. More specifically, the Stauntonia Hexaphylla extract efficiently inhibits secretion of NO, suppresses expression of iNOS related to production of NO, and inhibits activities of cyclooxygenase (COX) enzymes which progress inflammatory response associated with biosynthesis of prostaglandin present in the body. In addition, it has been found that, among various solvent fractions of Stauntonia Hexaphylla leaf extracts, an ethyl acetate fraction efficiently inhibits both NO production and COX enzyme activity, as compared to other solvent fractions, so long as problems associated with toxicity are not generated.
[0033] In addition, during research associated with anti-inflammatory agents derived from natural substances, the inventors of the present invention found that a Stauntonia Hexaphylla extract exhibits superior anti-pyretic effects. More specifically, the Stauntonia Hexaphylla extract is found to have remarkably superior anti-pyretic effects, whereas other plant extracts having anti-inflammatory effects have no or almost no anti-pyretic effects. In addition, it has been found that, among various solvent fractions of Stauntonia Hexaphylla extracts, an ethyl acetate fraction exhibits superior anti-pyretic effects, as compared to other fractions, so long as problems associated with toxicity are not generated.
[0034] Hereinafter, the prevent invention will be described in more detail.
[0035] The present invention is directed to an anti-inflammatory composition comprising a Stauntonia Hexaphylla extract as an active ingredient.
[0036] Stauntonia Hexaphylla is a creeping evergreen plant of dicotyledonous ranales Lardizabalaceae, which is also called “ Stauntonia Hexaphylla tree”.
[0037] Stauntonia Hexaphylla is a monoecism. Leaves of Stauntonia Hexaphylla are alternate phyllotaxis and palmately compound leaves composed of five to seven small leaflets. Flowers of Stauntonia Hexaphylla bloom in May, are yellowish white in color and are racemous inflorescence. Fruits of Stauntonia Hexaphylla are egg-shaped or oval berries and have a length of 5 cm to 10 cm, ripen to reddish brown in October, and flesh thereof is more delicious than clematis berries. Seeds of Stauntonia Hexaphylla have an egg-like oval shape and are black in color. Stauntonia Hexaphylla is predominantly found in Korea, Japan, Taiwan or China. Stauntonia Hexaphylla is mainly grown in the valleys and woods in the south regions such as Jeollanam-do, Gyeongsangnam-do and Chungcheongnam-do in Korea.
[0038] The Stauntonia Hexaphylla extract may be produced in accordance with a common production method of plant extracts. For example, the Stauntonia Hexaphylla extract is produced by extracting fruits, flowers, leaves, branches, stems, roots or peels of Stauntonia Hexaphylla , or grains obtained by crushing these substances (hereinafter, simply referred to as “grains”) preferably leaves of Stauntonia Hexaphylla or fruits of Stauntonia Hexaphylla , more preferably leaves of Stauntonia Hexaphylla , with an extraction solvent, or by extracting the same with an extraction solvent and then fractionating the resulting crude extracts with a fractionation solvent. Leaves of Stauntonia Hexaphylla are harvested in a great amount as compared to other sites thereof, are thus easy to produce and exhibit superior anti-inflammatory effects. Accordingly, the Stauntonia Hexaphylla extract is preferably a Stauntonia Hexaphylla leaf extract.
[0039] The extraction solvent may comprise at least one selected from the group consisting of water and organic solvents. The organic solvent may be a polar solvent such as alcohol having 1 to 5 carbon atoms, diluted alcohol, ethyl acetate or acetone, a non-polar solvent such as ether, chloroform, benzene, hexane or dichloromethane, or a mixture thereof. The alcohol having 1 to 5 carbon atoms may be methanol, ethanol, propanol, butanol, isopropanol or the like, but the present invention is not limited thereto. In addition, the diluted alcohol may be obtained by diluting alcohol with water at a concentration of 50% (v/v) to 99.9% (v/v).
[0040] The extraction solvent of the Stauntonia Hexaphylla extract preferably comprises at least one selected from the group consisting of water, alcohols having 1 to 5 carbon atoms, diluted alcohol and mixtures thereof, more preferably comprises at least one selected from the group consisting of water, alcohols having 1 to 4 carbon atoms and a mixture thereof, and even more preferably comprises water.
[0041] The extraction may be carried out 50° C. to 150° C., or 75° C. to 130° C., or 90° C. to 120° C., but the present invention is not limited thereto. In addition, the extraction time is not particularly limited, but may be 10 minutes to 12 hours, or 30 minutes to 6 hours, or 2 hours to 4 hours.
[0042] The Stauntonia Hexaphylla extract according to the present invention may be produced in accordance with a general method of producing plant extracts. Specifically, the method may be hot extraction including hot water extraction, cold-immersion extraction, warm-immersion extraction, ultrasonic extraction or the like and may be carried out using an ordinary extractor, ultrasonic extractor or fractionator.
[0043] In addition, the extract extracted with a solvent may then be subjected to fractionation using at least one solvent selected from the group consisting of hexane, chloroform, ethyl acetate, methylene chloride, ethyl ether, acetone, butanol, water and mixtures thereof. The solvent used for fractionation may be a combination of two or more types and may be used sequentially or in combination according to the polarity of solvent to prepare respective solvent extracts.
[0044] A fraction of the Stauntonia Hexaphylla extract is preferably an ethyl acetate fraction or a chloroform fraction, more preferably an ethyl acetate fraction.
[0045] The prepared extract or the fraction obtained by the fractionation process may then be subjected to filtration, concentration and/or drying to remove the solvent. Specifically, the filtration may be carried out using a filter paper or vacuum filter, the concentration may be carried out by vacuum-concentration using a vacuum concentrator, for example, a rotary evaporator, and the drying may be for example freeze-drying.
[0046] The Stauntonia Hexaphylla extract, for example, a Stauntonia Hexaphylla leaf hot water extract or a Stauntonia Hexaphylla fruit hot water extract is found to have no cytotoxicity even when treated at a concentration of 200 μg/Ml as a result of MTT analysis.
[0047] Accordingly, the anti-inflammatory composition may be used to inhibit inflammation, or to treat, relieve, alleviate or prevent inflammation.
[0048] The inflammation includes general inflammatory diseases and the inflammatory diseases for example include one or more selected from the group consisting of various chronic inflammatory diseases, such as various dermatitis including atopic dermatitis, dermatomyositis, polymyositis, allergies, systemic lupus erythematosus, pemphigus, aphthous stomatitis, retinitis, gastritis, hepatitis, bronchitis, esophagitis, colitis, pancreatitis, colitis, nephritis, decubitus, lupus, chronic thyroiditis and multiple sclerosis, various acute inflammatory diseases such as sepsis, shock, radiation injury and organ transplant rejection, generalized edema and localized edema.
[0049] Accordingly, the anti-inflammatory composition may be used to treat, prevent or relieve inflammatory diseases.
[0050] The allergies include anaphylaxis, allergic rhinitis, asthma, allergic conjunctivitis, allergic dermatitis, atopic dermatitis, contact dermatitis, urticaria, insect allergies, food allergies and medication allergies.
[0051] The generalized edema may specifically be selected from the group consisting of congestive heart failure, constrictive pericarditis, restrictive cardiomyopathy, liver cirrhosis, renal failure, nephrotic syndrome and a combination thereof. The localized edema is a swelling of a portion of skin and soft tissues, and specifically includes cellulitis accompanied with inflammation of the skin and soft tissues, drainage disorders of veins or lymphatic vessels, burns accompanied with partial loss of the skin and soft tissues, insect bites, and bacterial infection.
[0052] Accordingly, the anti-inflammatory composition of the present invention may be applied as a composition for treating or preventing inflammatory diseases, or a food composition for treating or preventing inflammatory diseases. The food composition is for example a health functional food composition for preventing or relieving inflammatory diseases.
[0053] The health functional food means a group of foods having added values provided by physical, biochemical and biotechnological methods so that the corresponding food performs or exerts intended functions suitable for specific applications, or a processed food to be designed so that a composition of the food sufficiently exhibits desired body modulation functions such as biological defense rhythm control, and disease prevention and restoration.
[0054] The health functional food may comprise a sitologically acceptable food auxiliary additive, and may further include a suitable carrier, excipient and diluent commonly used for preparation of health functional foods.
[0055] The health functional food composition for preventing or relieving inflammatory diseases according to the present invention may comprise the Stauntonia Hexaphylla extract in an amount of 0.001% by weight to 99.9% by weight or 0.01% by weight to 50% by weight or 0.1% by weight to 30% by weight or 0.1% by weight to 15% by weight, based on the total weight of the food.
[0056] The anti-inflammatory composition may be used as a drug ingredient or for medical or pharmaceutical applications. In this regard, the anti-inflammation composition may be a medical composition, for example, an anti-pyretic and analgesic drug.
[0057] The anti-inflammatory composition comprising the Stauntonia Hexaphylla extract as an active ingredient may be directly applied to animals including humans. The animals are a family of organisms, contrast to plants, which mainly intake organic matter as nutrients and are differentiated into digestive, excretory and respiratory organs, and are preferably mammals, more preferably humans.
[0058] The Stauntonia Hexaphylla extract may be used alone in the anti-inflammatory composition and may further comprise a pharmaceutically acceptable carrier, excipient, diluent or adjuvant. More specifically, when the composition comprising the Stauntonia Hexaphylla extract may be used as a drug ingredient or for medical or pharmaceutical applications, the Stauntonia Hexaphylla extract may be mixed with a pharmaceutically acceptable carrier or excipient or be diluted with a diluting agent in accordance with a general method before use.
[0059] In this case, a content of the Stauntonia Hexaphylla extract in the composition may be 0.001% by weight to 99.9% by weight, 0.1% by weight to 99% by weight or 1% by weight to 50% by weight, but the present invention is not limited thereto. The content of the extract may be controlled to a reasonable level according to usage form and method of the composition.
[0060] Examples of the pharmaceutically acceptable carrier, excipient or diluent include, but are not limited to, one or more selected from the group consisting of lactose, dextrose, sucrose, sorbitol, mannitol, xylitol, erythritol, maltitol, starch, acacia rubber, alginate, gelatin, calcium phosphate, calcium silicate, cellulose, methyl cellulose, microcrystalline cellulose, polyvinylpyrrolidone, water, methyl hydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate, mineral oil, dextrin, calcium carbonate, propylene glycol, liquid paraffin, and physiological saline, but any ordinary carrier, excipient or diluent may be used without limitation to these substances. In addition, the pharmaceutical composition may further comprise ordinary fillers, extenders, binders, disintegrating agents, anti-agglutinating agents, lubricating agents, wetting agents, pH control agents, nutrients, vitamins, electrolytes, alginic acid and salts thereof, pectic acid and salts thereof, protective colloids, glycerin, flavoring agents, emulsifiers or preservatives. These ingredients may be added singly or in combination to the Stauntonia Hexaphylla extract, the active ingredient.
[0061] In addition, the composition of the present invention may further comprise, in addition to the active ingredient, well-known substances determined to have anti-inflammatory effects, for example, substances used as COX-2 inhibitors, NO inhibitors or anti-inflammatory drugs.
[0062] The composition may be administered orally or parenterally when used as a drug ingredient and the composition may be, for example, administered through various routes including oral, transdermal, subcutaneous, intravenous and muscular routes.
[0063] In addition, a formulation of the composition may be varied according to usage form and the composition may be formulated by a method well-known in the art so that the active ingredient is rapidly, sustained or delayed released after administration to a mammalian animal. Generally, solid preparations for oral administration include tablets, caplets, soft or hard capsules, pills, powders, granules and the like. These preparations may be, for example, prepared by mixing one or more excipients, such as starch, calcium carbonate, sucrose, lactose and gelatin. In addition, in addition to a simple excipient, lubricants such as magnesium stearate or talc may also be used. Liquid preparations for oral administration include suspensions, liquids and solutions for internal use, emulsions, syrups and the like. The liquid preparations may comprise various excipients, for example, wetting agents, sweeting agents, flavoring agents and preservatives, in addition to water and liquid paraffin which are commonly used simple diluents.
[0064] Preparations for parenteral administration include creams, lotions, ointments, plasters, liquids and solutions, aerosols, fluid extracts, elixirs, infusions, sachets, patches, injections and the like.
[0065] Furthermore, the composition of the present invention may be formulated using a reasonable method well-known in the art to which the present invention pertains or a method described in the Remington's Pharmaceutical Science (recent edition, Mack Publishing Company, Easton Pa.).
[0066] Dose of the composition may be determined in consideration of dosage method, age and sex of takers, severity and conditions patients, intake of active ingredient in the body, inactivation ratio and drugs used in conjunction therewith. The dose may be for example 0.1 mg/kg (body weight) to 500 mg/kg (body weight), 0.1 mg/kg (body weight) to 400 mg/kg (body weight) or 1 mg/kg (body weight) to 300 mg/kg (body weight), based on the active ingredient per day. The composition may be administered once or in several portions. The dose is not construed as limiting the scope of the present invention in any aspect.
[0067] In addition, the present invention provides an anti-inflammatory composition comprising the Stauntonia Hexaphylla extract as an active ingredient.
[0068] In addition, the present invention provides an anti-inflammatory drug comprising the Stauntonia Hexaphylla extract as an active ingredient.
[0069] The Stauntonia Hexaphylla extract is preferably a Stauntonia Hexaphylla leaf hot water extract, more preferably an ethyl acetate fraction of a Stauntonia Hexaphylla leaf hot water extract.
[0070] The anti-inflammatory drug may comprise the active ingredient alone and may further comprise a pharmaceutically acceptable carrier or excipient according to formulation, usage form and usage purpose. When the anti-inflammatory drug is provided as a mixture, the active ingredient may be present in an amount of 0.1% by weight to 99.9% by weight, with respect to the total weight of the anti-inflammatory drug, but is generally present in an amount of 0.001% by weight to 50% by weight.
[0071] The anti-inflammatory drug may be used for preventing and treating various chronic inflammatory diseases such as lupus and multiple sclerosis, various acute inflammatory diseases such as sepsis, shock, radiation injury and organ transplant rejection, ophthalmologic diseases, bronchitis, or inflammatory bowel diseases.
[0072] Examples of the carrier or excipient include, but are not limited to, water, dextrin, calcium carbonate, lactose, propylene glycol, liquid paraffin, physiological saline, dextrose, sucrose, sorbitol, mannitol, xylitol, erythritol, maltitol, starch, gelatin, calcium phosphate, calcium silicate, cellulose, methyl cellulose, polyvinyl pyrrolidone, methyl hydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate and mineral oil. The carrier or excipient may be used in combination of two or more types.
[0073] In addition, when the anti-inflammatory drug is provided as a medicine, the medicine may further comprise ordinary fillers, extenders, binders, disintegrating agents, surfactants, anti-agglutinating agents, lubricating agents, wetting agents, flavorings, emulsifiers, preservatives or the like.
[0074] In addition, the anti-inflammatory drug of the present invention may further comprise, in addition to the active ingredient, a well-known compound or plant extract having anti-inflammatory activity, and the compound or the plant extract may be present in an amount of 0.1 parts by weight to 99.9 parts by weight or 0.5 parts by weight to 20 parts by weight, with respect to 100 parts by weight of the active ingredient.
[0075] The anti-inflammatory drug may be formulated into a suitable form determined according to usage form and in particular, may be formulated by a method well-known in the art so that the active ingredient is rapidly, sustained or delayed released after administration to a mammalian animal. Specifically, examples of the formulation include plasters, granules, lotions, liniments, limonages, powders, syrups, eye ointments, liquids and solutions, aerosols, extracts, elixirs, ointments, fluidextracts, emulsions, suspensions, decoctions, infusions, eye drops, tablets, suppositories, injections, spirits, capsules, creams, pills, soft or hard gelatin capsules and the like.
[0076] The anti-inflammatory drug according to the present invention may be administered orally or parenterally and may be, for example, used through dermal, intramuscular, intraperitoneal, intravenous, subcutaneous, nasal, epidural and oral routes. The dose may be determined in consideration of dosage method, age, sex and body weight of takers, severity of diseases and the like. For example, the anti-inflammatory drug of the present invention may be administered one or more times in a daily dose of 0.1 mg/kg (body weight) to 100 mg/kg (body weight), based on the active ingredient. However, the dose is provided only as an example and the present invention is not limited thereto.
[0077] In addition, the present invention provides a cosmetic composition comprising the Stauntonia Hexaphylla extract as an active ingredient.
[0078] The Stauntonia Hexaphylla extract is free of both problems associated with side effects because it is derived from a natural substance, has no cytotoxicity, and efficiently regulates inflammation induced by ingredients contained in cosmetics and inflammation induced by external environments due to potent inflammation-inhibitory effect and thus superior anti-inflammatory and anti-irritant activities. Accordingly, the Stauntonia Hexaphylla extract may be used as an active ingredient of the cosmetic composition having the effects of relieving, preventing and alleviating inflammation. In this regard, the cosmetic composition may be a cosmetic composition for relieving or alleviating inflammation.
[0079] The Stauntonia Hexaphylla extract is preferably a Stauntonia Hexaphylla leaf hot water extract, more preferably an ethyl acetate fraction of a Stauntonia Hexaphylla hot water extract.
[0080] The cosmetic composition may be utilized in applications including skin-care cosmetics, make-up cosmetics, body cosmetics, hair cosmetics, scalp cosmetics, shaving cosmetics or oral cosmetics.
[0081] Examples of the skin-care cosmetics include creams, lotions, packs, massage creams, emulsions and the like, examples of the makeup cosmetics include foundations, makeup bases, lipsticks, eye shadows, eyeliners, mascaras, eyebrow pencils and the like, and examples of body cosmetics include soaps, liquid detergents, bath preparations, sunscreen creams, sunscreen oils and the like. Examples of the hair cosmetics include hair shampoos, conditioners, hair treatments, hair mousse, hair liquids, pomade, hair colors, hair bleaches, color rinses and the like, and examples of the scalp cosmetics include hair tonics, scalp treatments or the like. Examples of the shaving cosmetics include aftershave lotions or shaving creams and examples of the oral cosmetics include toothpaste, mouth washes and the like.
[0082] In addition to the active ingredient, ingredients commonly blended with cosmetic compositions, for example, humectants, UV absorbers, vitamins, animal and plant extracts, digesters, whitening agents, vasodilators, astringents, refreshing agents and hormone drugs, may be further blended with the cosmetic composition, according to intended use and properties of the cosmetic composition. In addition, the cosmetic composition may further comprise a base ingredient to permeate or migrate the drug or the active ingredient into skin tissues.
[0083] The formulation of the cosmetic composition may be provided as a suitable form according to intended use and properties of the cosmetic composition and examples of the formulation include aqueous solutions, solubilizing agents, emulsions, oils, gels, pastes, ointments, aerosols, water-oil di-layer systems or water-oil-powder tri-layer systems. The examples of the formulation are provided only for exemplification and are not construed as limiting the formulation and form of the cosmetic composition of the present invention.
[0084] The active ingredient may be present in an amount of 0.001% by weight to 50% by weight, preferably 0.01% by weight to 20% by weight, based on the total weight of the cosmetic composition, but the content may be suitably controlled according to contents of ingredients, other than the active ingredient, contained in the formulation or the cosmetic composition, and is not construed as limiting the content of the active ingredient according to the present invention.
[0085] The present invention is directed to an anti-pyretic composition comprising a Stauntonia Hexaphylla extract as an active ingredient.
[0086] The Stauntonia Hexaphylla extract may be produced in accordance with a common production method of plant extracts. For example, the Stauntonia Hexaphylla extract is produced by extracting leaves, branches, stems, roots or peels of Stauntonia Hexaphylla , or grains obtained by crushing these substances (hereinafter, simply referred to as “grains”), preferably leaves of Stauntonia Hexaphylla , with an extraction solvent, or by extracting the same with an extraction solvent and then fractionating the resulting crude extract with a fractionation solvent.
[0087] Leaves of Stauntonia Hexaphylla are harvested in a great amount as compared to other sites thereof, are thus easy to produce and exhibit superior anti-inflammatory effects. Accordingly, the Stauntonia Hexaphylla extract is preferably a Stauntonia Hexaphylla leaf extract.
[0088] The extraction solvent may comprise at least one selected from the group consisting of water and organic solvents. The organic solvent may be a polar solvent such as alcohol having 1 to 5 carbon atoms, diluted alcohol, ethyl acetate or acetone, a non-polar solvent such as ether, chloroform, benzene, hexane or dichloromethane, or a mixture thereof.
[0089] The extraction solvent of the Stauntonia Hexaphylla extract preferably comprises at least one selected from the group consisting of water, alcohols having 1 to 5 carbon atoms, diluted alcohol and mixtures thereof, more preferably comprises any one selected from the group consisting of water, alcohols having 1 to 4 carbon atoms and a mixture thereof, and even more preferably comprises water. The extraction may be carried out 50° C. to 150° C., or 75° C. to 120° C., or 90° C. to 115° C., but the present invention is not limited thereto. In addition, the extraction time is not particularly limited, but may be 10 minutes to 12 hours, or 30 minutes to 8 hours, or 2 hours to 6 hours.
[0090] The Stauntonia Hexaphylla leaf extract according to the present invention may be produced in accordance with a general method of producing plant extracts. Specifically, the method may be hot extraction including hot water extraction, cold-immersion extraction, warm-immersion extraction, ultrasonic extraction or the like and may be carried out using an ordinary extractor, ultrasonic extractor or fractionator.
[0091] In addition, the extract extracted with a solvent may then be subjected to fractionation using at least one solvent selected from the group consisting of hexane, chloroform, methylene chloride, ethyl acetate, ethyl ether, acetone, butanol, water and mixtures thereof. The solvent used for fractionation may be a combination of two or more types and may be used sequentially or in combination according to the polarity of solvent to prepare respective solvent extracts.
[0092] A fraction of the prepared Stauntonia Hexaphylla solvent extract, specifically, a fraction of the Stauntonia Hexaphylla leaf hot water extract is preferably an ethyl acetate fraction, a chloroform fraction or a butanol fraction, more preferably an ethyl acetate fraction or a chloroform fraction, even more preferably, an ethyl acetate fraction.
[0093] The prepared extract or the fraction obtained by the fractionation process may then be subjected to filtration, concentration and/or drying to remove the solvent. Specifically, the filtration may be carried out using a filter paper or vacuum filter, the concentration may be carried out by vacuum-concentration using a vacuum concentrator, for example, a rotary evaporator, and the drying may be for example freeze-drying.
[0094] The anti-pyretic composition may be used as a drug or for medical or pharmaceutical applications. In this regard, the anti-pyretic composition may be a medical composition, for example, an anti-pyretic drug, or an anti-pyretic and analgesic drug.
[0095] When the anti-pyretic composition is used for medical or pharmaceutical applications, the anti-pyretic composition may be used for inhibiting abnormal generated heat (fever) or treating or preventing abnormal fever accompanied by diseases.
[0096] In this regard, the present invention is directed to an anti-pyretic composition comprising the Stauntonia Hexaphylla extract as an active ingredient. The anti-pyretic composition comprising the Stauntonia Hexaphylla extract, preferably, the Stauntonia Hexaphylla leaf extract, as an active ingredient, may be used for inhibiting, treating, relieving or preventing abnormal fever or abnormal fever accompanied by diseases or disorders and may be specifically an anti-pyretic and analgesic drug.
[0097] Regarding the anti-pyretic composition comprising the Stauntonia Hexaphylla extract as an active ingredient, the Stauntonia Hexaphylla extract is a Stauntonia Hexaphylla leaf extract, preferably a chloroform fraction, an ethyl acetate fraction or a butanol fraction of the Stauntonia Hexaphylla leaf extract, more preferably, an ethyl acetate fraction or a chloroform fraction of the Stauntonia Hexaphylla leaf extract, even more preferably an ethyl acetate fraction of the Stauntonia Hexaphylla leaf extract.
[0098] The abnormal fever means an abnormally high body temperature.
[0099] The anti-pyretic drug is used to eliminate abnormal fever and refers to a medicine used to lower an abnormally elevated body temperature to a reasonable level. Previously reported anti-pyretic drugs include antipyrin, antifebrin, aspirin, salipyrin and the like. The anti-pyretic drug is also called an “anti-pyretic and analgesic drug” because it generally has the effect of alleviating pain.
[0100] The anti-pyretic composition comprising the Stauntonia Hexaphylla extract as an active ingredient may be directly applied to animals including humans. The animals are a family of organisms, contrast to plants, which mainly intake organic matter as nutrients and are differentiated into digestive, excretory and respiratory organs, and are preferably mammals, more preferably humans.
[0101] The Stauntonia Hexaphylla extract may be used alone in the anti-pyretic composition and a pharmaceutically acceptable carrier, excipient, diluent or adjuvant may further added.
[0102] More specifically, when the composition comprising the Stauntonia Hexaphylla extract may be used as a drug or for medical or pharmaceutical applications, the Stauntonia Hexaphylla extract may be mixed with a pharmaceutically acceptable carrier or excipient or be diluted with a diluting agent in accordance with a general method before use.
[0103] In this case, a content of the Stauntonia Hexaphylla extract in the composition may be 0.001% by weight to 99.9% by weight, 0.1% by weight to 99% by weight or 1% by weight to 50% by weight, but the present invention is not limited thereto. The content of the extract may be controlled to a reasonable level according to usage form and method of the composition.
[0104] Examples of the pharmaceutically acceptable carrier, excipient or diluent include, but are not limited to, one or more selected from the group consisting of lactose, dextrose, sucrose, sorbitol, mannitol, xylitol, erythritol, maltitol, starch, acacia rubber, alginate, gelatin, calcium phosphate, calcium silicate, cellulose, methyl cellulose, microcrystalline cellulose, polyvinylpyrrolidone, water, methyl hydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate, mineral oil, dextrin, calcium carbonate, propylene glycol, liquid paraffin, and physiological saline, but any ordinary carrier, excipient or diluent may be used without limitation to these substances. The carrier or the excipient may be used in combination of two or more types.
[0105] In addition, the anti-pyretic composition may further comprise ordinary fillers, extenders, binders, disintegrating agents, anti-agglutinating agents, lubricating agents, wetting agents, pH control agents, nutrients, vitamins, electrolytes, alginic acid and salts thereof, pectic acid and salts thereof, protective colloids, glycerin, flavoring agents, emulsifiers or preservatives. These ingredients may be added singly or in combination to the Stauntonia Hexaphylla extract, the active ingredient.
[0106] In addition, the anti-pyretic composition may further comprise, in addition to the active ingredient, a well-known substance considered to have anti-pyretic effect.
[0107] In addition, the anti-pyretic drug may further comprise, in addition to the active ingredient, a well-known compound or plant extract considered to have anti-pyretic effect and may be present in an amount of 0.1 parts by weight to 99.9 parts by weight or 0.5 parts by weight to 20 parts by weight, based on 100 parts by weight of the active ingredient.
[0108] The composition may be administered orally or parenterally when used for a drug and the composition may be, for example, administered through various routes including oral, transdermal, subcutaneous, intravenous and muscular routes.
[0109] In addition, a formulation of the composition may be varied according to usage form and the composition may be formulated by a method well-known in the art so that the active ingredient is rapidly, sustained or delayed released after administration to a mammalian animal.
[0110] Generally, solid preparations for oral administration include tablets, caplets, soft or hard capsules, pills, powders, granules and the like. These preparations may be, for example, prepared by mixing one or more excipients, such as starch, calcium carbonate, sucrose, lactose and gelatin. In addition, in addition to a simple excipient, lubricants such as magnesium stearate or talc may also be used. Liquid preparations for oral administration include suspensions, liquids and solutions for internal use, emulsions, syrups and the like. The liquid preparations may comprise various excipients, for example, wetting agents, sweeting agents, flavoring agents and preservatives, in addition to water and liquid paraffin which are commonly used simple diluents.
[0111] Preparations for parenteral administration include creams, lotions, ointments, plasters, liquids and solutions, aerosols, fluid extracts, elixirs, infusions, sachets, patches, injections and the like.
[0112] Furthermore, the composition of the present invention may be formulated using a reasonable method well-known in the art to which the present invention pertains or a method described in the Remington's Pharmaceutical Science (recent edition, Mack Publishing Company, Easton Pa.).
[0113] Dose of the composition may be determined in consideration of dosage method, age and sex of takers, severity and conditions of patients, intake of active ingredient in the body, inactivation ratio and drugs used in conjunction therewith. The dose may be for example 0.1 mg/kg (body weight) to 500 mg/kg (body weight), 0.1 mg/kg (body weight) to 400 mg/kg (body weight) or 1 mg/kg (body weight) to 300 mg/kg (body weight), based on the active ingredient per day. The composition may be administered once or in several portions. The dose is not construed as limiting the scope of the present invention in any aspect.
Advantageous Effects
[0114] The Stauntonia Hexaphylla extract of the present invention is an edible plant-derived extract, is free of problems associated with side effects and safety, is determined to have considerably low cytotoxicity as a result of MTT analysis and exhibits anti-inflammatory and anti-pyretic effects, thus being used for medicines or cosmetics requiring anti-inflammatory effects and medications requiring anti-pyretic effects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0115] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0116] FIG. 1 is a schematic diagram illustrating a process of preparing a Stauntonia Hexaphylla leaf hot water extract and solvent fractions thereof according to an embodiment of the present invention;
[0117] FIG. 2 is a schematic diagram illustrating a process of preparing a Stauntonia Hexaphylla fruit hot water extract and solvent fractions thereof according to an embodiment of the present invention;
[0118] FIG. 3 is a graph showing measurement results of cytotoxicity of the Stauntonia Hexaphylla leaf extract using RAW264.7 cell lines by MTT assay according to an embodiment of the present invention, wherein + means treated with LPS (1 μg/Ml) or the extract, − means non-treated, an SHL value of a horizontal axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla leaf hot water extract and a vertical axis represents relative cytotoxicity (%) as compared to a control group not-treated with any sample;
[0119] FIG. 4 is a graph showing measurement results of cytotoxicity of the Stauntonia Hexaphylla fruit extract using RAW264.7 cell lines by MTT assay according to an embodiment of the present invention, wherein + means treated with LPS (1 μg/MB) or the extract, − means non-treated, an SH value of a vertical axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla fruit hot water extract;
[0120] FIG. 5 is a graph showing NO secretion measured to determine anti-inflammatory effects of the Stauntonia Hexaphylla leaf hot water extract using RAW264.7 cell lines according to an embodiment of the present invention, wherein + means treated together with LPS (1 μg/Ml), − means non-treated with LPS (1 μg/Ml), an SHL value of a horizontal axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla leaf hot water extract and a vertical axis represents relative NO secretion (%) as compared to a control group treated only with LPS;
[0121] FIG. 6 is a graph showing mRNA levels of inflammation-associated cytokine measured to determine anti-inflammatory effects of the Stauntonia Hexaphylla leaf hot water extract according to an embodiment of the present invention, wherein + means treated with LPS (1 μg/Ml) or a solvent fraction, − means non-treated with any sample, and a value of a horizontal axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla leaf hot water extract;
[0122] FIG. 7 is a graph showing expression of iNOS and COX-2 measured to determine anti-inflammatory effects of the Stauntonia Hexaphylla leaf hot water extract according to an embodiment of the present invention wherein, + means treated with LPS (1 μg/Ml) or a solvent fraction, − means non-treated with any sample, and a value of a horizontal axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla leaf hot water extract;
[0123] FIG. 8 is a graph showing levels of transferred mRNA of inflammation-associated cytokines detected by RT-PCR to determine anti-inflammatory effects of the Stauntonia Hexaphylla fruit hot water extract according to an embodiment of the present invention using macrophage primary cells, wherein + means treated with LPS (1 μg/Ml), − means non-treated with LPS (1 μg/Ml), an SHL value of a horizontal axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla fruit hot water extract and a vertical axis represents a type of cytokines;
[0124] FIG. 9 is a graph showing produced levels of TNF-α among inflammation-associated cytokines to determine anti-inflammatory effects of the Stauntonia Hexaphylla fruit hot water extract using macrophage primary cells according to an embodiment of the present invention, wherein + means treated together with LPS (1 μg/Ml), − means non-treated with LPS, a horizontal axis represents a dose (μg/Ml) of the Stauntonia Hexaphylla fruit hot water extract and a vertical axis represents a level of produced TNF-α;
[0125] FIG. 10 is a graph showing cytotoxicity of the Stauntonia Hexaphylla leaf hot water extract measured by MTT assay using RAW264.7 cell lines according to an embodiment of the present invention, wherein + means treated with LPS (1 μg/Ml) or a solvent fraction, − means not treated with any sample, values of a horizontal axis represents doses (μg/Ml) of different solvent fractions of the Stauntonia Hexaphylla leaf hot water extract and a vertical axis represents cytotoxicity (%) as compared to a control group not treated with any sample;
[0126] FIG. 11 is a graph showing levels of secreted NO measured to determine anti-inflammatory effects of different solvent fractions of the Stauntonia Hexaphylla leaf hot water extract using RAW264.7 cell lines according to an embodiment of the present invention, wherein + means treated with LPS (1 μg/Ml) or the solvent fraction, − means not treated with any sample, characters and values of a horizontal axis represent types and doses (50 μg/Ml) of different solvent fractions of the Stauntonia Hexaphylla leaf hot water extract and a vertical axis represents relative NO secretion (%) as compared to a control group treated only with LPS;
[0127] FIG. 12 is a graph showing COX-2 inhibitory activity measured based on COX-2 activity to determine anti-inflammatory effects of the solvent fractions of the Stauntonia Hexaphylla leaf hot water extract according to an embodiment of the present invention, wherein solvents distinguishing different curves represent fractionation solvents, a horizontal axis represents time passed after treatment and a vertical axis represents COX-2 activity;
[0128] FIG. 13 is a graph showing results of alleviation of fever induced by LPS in order to determine anti-inflammatory effects of the Stauntonia Hexaphylla leaf hot water extract using test animals according to an embodiment of the present invention, wherein a value of a horizontal axis represents time (hour, h) passed after administration with samples and a value of a vertical axis represents a measured body temperature; and
[0129] FIG. 14 is a graph showing results of alleviation of fever induced by LPS in order to determine anti-inflammatory effects of the fractions of the Stauntonia Hexaphylla leaf hot water extract according to an embodiment of the present invention using test animals, wherein a value of a horizontal axis represent time (hour, h) passed after administration with samples and values of a vertical axis represent variation in body temperature changed from a body temperature measured before sample administration, that is, value calculated by subtracting a body temperature of a test animal measured before sample administration from a body temperature of the test animal measured at the corresponding time.
DETAILED DESCRIPTION OF THE INVENTION
[0130] Hereinafter, configurations and effects of the present invention will be described in more detail with reference to specific examples and comparative examples for better understating of the present invention. The following examples are provided only for clear understanding only and should not be construed as limiting the scope and spirit of the present invention. The scope of the present invention to be protected should be interpreted by the claims and all technical concepts equivalent thereto fall within the scope of the present invention to be protected.
Example 1
Preparation of Stauntonia Hexaphylla Extract and Fraction
[0131] 1-1. Preparation of Stauntonia Hexaphylla Extract
[0132] A Stauntonia Hexaphylla leaf hot water extract was prepared at 110° C. using hot water and 10 kg of a Stauntonia Hexaphylla leaf in accordance with a hot water extraction method illustrated in FIG. 1 . In addition, a Stauntonia Hexaphylla fruit hot water extract was prepared at 100° C. using 40 L of hot water and 2,100 g of a Stauntonia Hexaphylla fruit in accordance with a hot water extraction method described in FIG. 2 .
[0133] More specifically, 200 L of distilled water was added to 10 kg of a Stauntonia Hexaphylla leaf washed with distilled water, and hot water extraction was then performed while heating the resulting mixture in an electric medicine boiling pot at 100° C. for 3 hours. In addition, 40 L of distilled water was added to 2,100 g of a Stauntonia Hexaphylla fruit washed with distilled water, and hot water extraction was then performed while heating the resulting mixture in an electric medicine boiling pot at 100° C. for 3 hours.
[0134] After the extraction, each extract was filtered through a 400 mesh filter cloth and the resulting filtrate was concentrated using a vacuum rotary concentrator. The residue left after the filtration was extracted, filtered and concentrated under vacuum two more times in the same manner as above using the equivalent amount of distilled water.
[0135] The Stauntonia Hexaphylla leaf hot water extract and the Stauntonia Hexaphylla fruit hot water extract prepared by the process were freeze-dried using a freeze-dryer. 1 kg of the Stauntonia Hexaphylla leaf hot water extract was obtained through the freeze-drying. As a result, a yield obtained by the Stauntonia Hexaphylla leaf hot water extraction was determined to be 10%. In addition, 148 g of the Stauntonia Hexaphylla fruit hot water extract was obtained through the freeze-drying. As a result, a yield obtained by the Stauntonia Hexaphylla fruit hot water extraction was determined to be 7%.
[0136] 1-2. Preparation of Fractions of Stauntonia Hexaphylla Extract
[0137] Fractions of the Stauntonia Hexaphylla leaf hot water extract and the Stauntonia Hexaphylla fruit hot water extract were prepared in accordance with the method illustrated in FIG. 1 or 2 .
[0138] Specifically, 250 g of the Stauntonia Hexaphylla leaf hot water extract was thoroughly dissolved in 5 L of distilled water, the resulting solution was charged in a fractionating column and 5 L of hexane was added thereto, followed by mixing and fractionation to separate a hexane layer as a hexane-soluble layer from an aqueous layer as a hexane-insoluble layer. The hexane layer was collected to prepare a hexane fraction solution.
[0139] 5 L of chloroform was added to the remaining solution (aqueous layer), followed by mixing and fractionation, to separate a chloroform layer as a chloroform-soluble layer and an aqueous layer as a chloroform-insoluble layer. The chloroform layer was collected to prepare a chloroform fraction solution.
[0140] 5 L of ethyl acetate was added to the remaining solution (aqueous layer), followed by mixing and fractionation, to separate an ethyl acetate layer as an ethyl acetate-soluble layer and an aqueous layer as an ethyl acetate-insoluble layer. The ethyl acetate layer was collected to prepare an ethyl acetate fraction solution.
[0141] 5 L of butanol was added to the remaining solution (aqueous layer), followed by mixing and fractionation, to separate a butanol layer as a butanol-soluble layer and an aqueous layer as a butanol-insoluble layer. The butanol layer was collected to prepare a butanol fraction solution.
[0142] The butanol-insoluble layer left after fractionation and separation of the butanol-soluble layer was concentrated to remove the remaining organic solvent, thereby preparing a water fraction solution.
[0143] The respective fraction solutions thus obtained were filtered in a vacuum filtration system, concentrated and freeze-dried at −20° C. to completely remove the solvents, which were used for the present experiment. Through the process, 0.02 g of a hexane fraction (0.015%), 0.67 g of a chloroform fraction (0.27%), 2 g of an ethyl acetate fraction (1.05%) and 68.75 g of a butanol fraction (27.5%) were obtained and used as samples.
[0144] In the preparation process, the hexane fraction was found to be unsuitable for use because it might cause problems associated with industrial processes due to excessively low yield. The obtained extracts and fractions were freeze-stored until they were used for experiments. In addition, the butanol and water fractions were found to have high yield, and economic efficiency and industrial applicability were thus considered to be excellent due to high fraction yields.
[0145] In addition, a fraction of the Stauntonia Hexaphylla fruit hot water extract was prepared by a method including completely dissolving 40 g of the Stauntonia Hexaphylla fruit hot water extract in 1 L of distilled water, respectively adding 1 L of fractionation solvents, that is, hexane, chloroform, ethyl acetate and butanol in a fractionating column in the same manner as above, followed by mixing and fractionation, thereby separating the solvent-soluble layers.
[0146] The fraction solutions of the Stauntonia Hexaphylla fruit hot water extract thus obtained were filtered in a vacuum filtration system, concentrated and freeze-dried at −20° C. to completely remove the solvents, which were then used in the present experiments. Through the process, 0.1 g of a hexane fraction, 0.6 g of a chloroform fraction, 2 g of an ethyl acetate fraction and 15 g of a butanol fraction were obtained and used as samples.
Example 2
Cytotoxicity Test of Extracts and Fractions
[0147] To determine cytotoxicity of the Stauntonia Hexaphylla leaf hot water extract, the Stauntonia Hexaphylla fruit hot water extract and the Stauntonia Hexaphylla leaf hot water extract fraction prepared in Example 1, mouse macrophage primary cells, RAW264.7 cells available from ATCC were used.
[0148] DMEM/F12 (Dulbecco's modified Eagle's medium/Nutrient Mixture Ham's F12), FBS (fetal bovine serum), L-glutamine and penicillin-streptomycin used for culturing the cells were obtained from Gibco/BRL (USA).
[0149] The RAW264.7 cells were cultured in a DMEM/F12 medium supplemented with 10% FBS, 1% penicillin-streptomycin and 1% L-glutamine and incubated at 37° C. and at a predetermined humidity in a CO 2 incubator (5% CO 2 /95% air).
[0150] The cells were cultured to a confluence of about 80% on a culture dish, and a monolayer of the cells was rinsed with PBS (pH 7.4) and then washed. Then, the cells were treated with 0.25% trypsin and 2.56 mmol/L of EDTA and were then passage-cultured. The cells were fed with a fresh medium every two days.
[0151] The cultured cells were seeded on a 48 well-plate at a density of 50,000 cells/well and further cultured for 24 hours. After 24 hours, a control group treated with only LPS, without treating with any sample, and experimental groups treated with LPS and solutions of the Stauntonia Hexaphylla leaf extracts and fractions thereof obtained in Example 1 prepared at different concentrations in DMSO which had been determined not to have any effect on cell viability were further cultured for 24 hours, the culture solutions were removed and the number of viable cells was measured by MTT assay. MTT assay was performed by the following method.
[0152] First, the cell culture medium was removed, each well was treated with 1 mL of a DMEM/F12 medium containing 1 mg/mL of MTT and the cells were further cultured at 37° C. and a predetermined humidity in a CO 2 incubator for 4 hours. After removing the medium, a tetrazolium bromide salt was removed, formazan crystals produced in each well were dissolved in 200 μl of DMSO, and absorbance at a wavelength of 540 nm was measured in a microplate reader (BIO-RAD) to determine cell viability.
[0153] Results of treatment with the Stauntonia Hexaphylla leaf extract were expressed as means of measured values obtained by repeating the test three times and are shown in FIG. 3 . Results of treatment with the Stauntonia Hexaphylla fruit extract were expressed as means of measured values obtained by repeating the test three times and are shown in FIG. 4 . Results of treatment with the fraction of the Stauntonia Hexaphylla leaf hot water extract were expressed as means of measured values obtained by repeating the test three times and are shown in FIG. 10 .
[0154] As can be seen from FIG. 3 , all groups treated with the Stauntonia Hexaphylla leaf hot water extract prepared in Example 1-1 at different concentrations, specifically, at different concentrations ranging from 50 μg/Ml to 200 μg/Ml, had no effects on cell proliferation even after 24 hours, as compared to the control group treated with only LPS, without treating with any sample. From the results, it was determined that the Stauntonia Hexaphylla leaf extract had no cytotoxicity at a concentration of less than or equal to 200 μg/Ml.
[0155] In addition, as can be seen from FIG. 4 , as a result of comparison between groups treated with the Stauntonia Hexaphylla fruit extract prepared in Example 1-1 at different concentrations, specifically, at different concentrations ranging from 50 μg/Ml to 200 μg/Ml, for 24 hours, and the control group treated with only LPS, without treating with any sample, all treated groups had no effects on cell proliferation. From the results, it was determined that the Stauntonia Hexaphylla fruit extract had no cytotoxicity at a concentration of less than or equivalent to 200 μg/Ml.
[0156] In addition, as can be seen from FIG. 10 , in case of the fractions of the Stauntonia Hexaphylla leaf hot water extract prepared in Example 1-2, an experimental group treated with 25 μg/Ml of the hexane fraction exhibited a significant decrease in cell viability, which demonstrated that the experimental group had cytotoxicity. In addition, an experimental group treated with 100 μg/Ml of the ethyl acetate fraction exhibited an insignificant and slight decrease in cell viability, whereas an experimental group treated with 200 μg/Ml of the ethyl acetate fraction exhibited a significant decrease in cell viability, which demonstrated that the ethyl acetate fraction was safe at a concentration of less than or equal to 100 μg/Ml. In case of other solvent fractions, cell viability was maintained at 50 μg/Ml or 100 μg/Ml, and fractions using solvents other than hexane, as fractionation solvents, had no cytotoxicity and were safe, when treated with the extract at a concentration of 50 μg/Ml.
Example 3
Determination of Anti-Inflammatory Effect of Stauntonia Hexaphylla Leaf Extract and Fraction Thereof
[0157] The RAW 264.7 cells cultured in Example 2 were used to determine anti-inflammatory effect of the Stauntonia Hexaphylla leaf extract and fractions thereof prepared in Example 1.
[0158] The cells were treated with the Stauntonia Hexaphylla leaf hot water extract or solvent fractions thereof prepared in Example 1, together with LPS, and cultured for 24 hours in the same manner as in Example 2. The cultured solution was centrifuged at 3,000 rpm for 5 minutes and a supernatant was separated. The supernatant was treated and reacted with an equal amount of Griess reagent (1% sulfanilamide, 0.1% naphthyl-ethylene diamine dihydrochloride, 2% phosphoric acid, Promega, USA), and NO secretion was measured at 540 nm. The results are shown in FIGS. 5 and 11 .
[0159] As can be seen from FIG. 5 , a control group not treated with LPS was found to exhibit low NO secretion. On the other hand, an experimental group treated with LPS was found to exhibit a prominent increase in NO secretion due to inflammation induced by LPS. In addition, in spite of treatment with LPS, groups treated with the Stauntonia Hexaphylla leaf hot water extract prepared in Example 1 exhibited a concentration-dependent decrease in NO secretion. In particular, a group treated with 100 μg/Ml of the Stauntonia Hexaphylla leaf hot water extract decreased NO secretion to 80% of the control group inflammation-induced by LPS, a group treated with 200 μg/Ml of the Stauntonia Hexaphylla leaf hot water extract decreased NO secretion to about 70% of the control group inflammation-induced by LPS, which demonstrated that the Stauntonia Hexaphylla leaf extract had anti-inflammatory effects.
[0160] The Stauntonia Hexaphylla leaf hot water extract had no effect on cell survival and was thus determined to have no cytotoxicity, when it was treated at a concentration of 200 μg/Ml in Example 2. Accordingly, the Stauntonia Hexaphylla leaf extract was determined to have no cytotoxicity, be safe and exhibit superior anti-inflammatory effect.
[0161] In addition, as can be seen from FIG. 11 , the water fraction exhibited almost no decrease in NO secretion, when treated with the extract at a concentration of 50 μg/Ml which had been determined to enable all fractions to be safe in Example 2. In addition, the butanol fraction was found to exhibit NO secretion corresponding to 60% of the control group and was thus considered to have anti-inflammatory effect. Meanwhile, the chloroform fraction and the ethyl acetate fraction of the Stauntonia Hexaphylla leaf hot water extract exhibited NO secretions which were equal to or less than 20% of the control group. This demonstrated that the ethyl acetate fraction and the chloroform fraction had remarkably excellent inhibitory effect on NO production at a concentration having no effect on cytotoxicity.
Example 4
Determination of Anti-Inflammatory Effect Through Measurement of Inflammation-Associated Cytokine mRNA Levels
[0162] To ascertain anti-inflammatory effect of the Stauntonia Hexaphylla leaf hot water extract which had been determined to exhibit superior anti-inflammatory effect based on NO secretion in Example 3 again, variation in mRNA level of inflammatory response-associated cytokine, specifically, iNOS was ascertained using macrophage primary cells.
[0163] In order to obtain macrophage primary cells, 32 4-week old male mice (ICR mouse) having a body weight of 15 g to 20 g and 32 Sprague-Dawley mice were obtained from Samtako Inc. (Korea), the respective mice were classified into 16 groups and 4 mice per group were placed and bred. The test animals were bred at a temperature of 20° C. to 24° C. and at a humidity of 60% to 70% under the day-night illumination condition at 12-hour intervals, and were freely fed with water and feed. The feed used herein was a solid feed (Samyang Feed Co., Korea). The test animals were bred under the same conditions for 7 days, adapted to laboratory environments and used for further testing.
[0164] Macrophage primary cells (2×10 6 cells/ml) obtained from the test animals were cultured in a serum starvation medium for 24 hours. After culturing, the cells were treated with LPS (0.5 mg/ml) or LPS (0.5 mg/ml) and different concentrations of the Stauntonia Hexaphylla leaf hot water extract and cultured for 24 hours. After 24 hours, RNA was isolated from the cultured cells. The RNA isolation was performed by the following method.
[0165] Specifically, the cultured cells were lysed in a GIT solution (easy BLUE Total RNA extraction kit, Intron Biotechnology Inc., Korea), and centrifuged at room temperature at 10,000 rpm for 5 minutes, and a supernatant was discarded to obtain a pellet. 1 ml of 0.1% DEPC solution (Sigma, USA) was added to the pellet, the resulting mixture was centrifuged at 12,000 rpm for 2 minutes again, and the supernatant was discarded to obtain a pellet. 0.5 ml of guanidinium was added to the obtained pellet, followed by vortexing. Furthermore, 0.5 ml of a phenol/chloroform/iso-amylalcohol mix solution (25:24:1) was added to the resulting mixture, followed by vortexing and centrifugation at 12,000 rpm for 3 minutes to obtain a supernatant. The supernatant was homogeneously mixed with an equal amount of iso-propylalcohol and allowed to stand at −20° C. for 30 minutes. Then, the resulting mixture was centrifuged at 12,000 rpm for 10 minutes, the supernatant was discarded, and the pellet was washed with a 70% aqueous ethanol solution and was dried under vacuum to isolate RNA.
[0166] The isolated RNA was dissolved in 1 ml of a 0.1% DEPC solution and was used to measure a content of mRNA of inflammation-associated cytokine. The mRNA content of the inflammation-associated cytokine, iNOS, was measured in accordance with the following method.
[0167] Superscript II reverse transcriptase (Invitrogen, USA) was added to 3 μg of the isolated RNA, followed by incubation at 42° C. for 105 minutes and then at 70° C. for 15 minutes, to obtain cDNA. The obtained cDNA was quantified by real-time PCR. Primer sequences and test conditions used for real-time PCR are shown in the following Table 1.
[0000]
TABLE 1
Target
Annealing
mRNA
Primer sequence
Tm(° C.)
iNOS
Sense
CAGAGGACCCAGAGACAAG
50.8
Anti-sense
ACCTGATGTTGCCATTGTTG
[0168] As a result of real-time PCR, an image showing comparison of iNOS content with β-actin content is shown in FIG. 6 .
[0169] As shown in FIG. 6 , a control group not treated with LPS did not exhibit mRNA of inflammation-associated cytokine, iNOS, at all, whereas a group treated only with LPS exhibited a remarkably high level of mRNA of iNOS. In addition, a group treated with the Stauntonia Hexaphylla leaf hot water extract prepared in Example 1, in spite of being treated with LPS, exhibited a concentration-dependent decrease in mRNA content of iNOS. The concentration-dependent decrease in iNOS mRNA content upon treatment with the Stauntonia Hexaphylla leaf hot water extract demonstrated that the Stauntonia Hexaphylla leaf hot water extract exhibited superior anti-inflammatory effects.
Example 5
Determination of Inhibitory Activity on Expression of Inflammation-Associated iNOS and COX-2
[0170] To ascertain anti-inflammatory effect of the Stauntonia Hexaphylla leaf hot water extract which had been determined to exhibit superior anti-inflammatory effect based on NO secretion and decrease in mRNA content of iNOS in Examples 3 and 4 again, inhibitory activity on expression of iNOS and COX-2 was confirmed.
[0171] Specifically, the macrophage primary cells obtained in Example 4 were plated on a 24 well plate at a density of 1×10 5 cells/ml controlled using a DMEM medium and pre-incubated in a 5% CO 2 incubator for 18 hours. After pre-culturing, the cells were treated with the Stauntonia Hexaphylla leaf hot water extract at different concentrations (0.1 μg/Ml, 1 μg/Ml, 10 μg/Ml, 100 μg/Ml and 200 μg/Ml), cultured for one hour, treated with LPS (1 μg/Ml) and cultured under the same conditions as the pre-culturing. After culturing for 24 hours, the cells were harvested, washed with phosphate buffered saline (PBS) three times, dissolved in cell lysis buffer (50 mM Tris-HCl (pH 7.5), 150 mM NaCl, 1% Nonidet P-40, 2 mM EDTA, 1 mM EGTA, 1 mM NaVO3, 10 mM NaF, 1 mM dithiothreitol, 1 mM phenylmethylsulfonyl fluoride, 25 μg/Ml aprotinin, 25 μg/Ml leupeptin) at 4° C. for 30 minutes, and centrifuged at 4° C. and 15,000 rpm for 15 minutes to remove cell membrane ingredients.
[0172] Protein concentration was quantified by standardizing bovine serum albumin (BSA) and using Bio-Rad Protein Assay Kit. 20 μg of the isolated protein was loaded on a 10% mini gel SDS-PAGE, and degenerated and separated, the protein was transferred to a nitrocellulose membrane (BIO-RAD, Richmond, Calif., USA) at 350 mA for one hour. The protein-transferred membrane was blocked in a TTBS (0.1% Tween 20+TBS) solution containing 5% skim milk at room temperature for 2 hours.
[0173] An anti-mouse iNOS (Calbiochem, La Jolla, USA) as an antibody used to detect an amount of expressed iNOS, and an anti-mouse COX-2 (BD Biosciences Pharmingen, San Jose, USA) as an antibody used to detect an amount of expressed COX-2, were diluted in TTBS solution at 1:1,000, reacted at room temperature for 2 hours and washed with TTBS three times. HRP (horse radish peroxidase)-conjugated anti-mouse IgG (Amersham Pharmacia Biotech, Little Chalfont, UK) as a secondary antibody was diluted at 1:5,000, reacted at room temperature for 30 minutes, washed with TTBS three times, and reacted with an ECL substrate (Amersham Biosciences, Piscataway, N.J., USA) for 30 seconds and amounts of expressed iNOS and COX-2 were measured using a chemiluminescence imaging system (ATTO AE-9150 EZ-Capture II, Japan). Measurement results of the expressed amounts are shown in FIG. 7 .
[0174] As can be seen from FIG. 7 , a control group not treated with LPS did not exhibit inflammation-associated proteins, that is, iNOS and COX-2, whereas a group treated only with LPS exhibited remarkably high levels of iNOS and COX-2. In addition, a group treated with the Stauntonia Hexaphylla leaf hot water extract prepared in Example 1, in spite of treatment with LPS, exhibited a concentration-dependent decrease in iNOS and COX-2 contents. The concentration-dependent decrease in iNOS and COX-2 contents upon treatment with the Stauntonia Hexaphylla leaf hot water extract demonstrated that the Stauntonia Hexaphylla leaf hot water extract exhibited superior anti-inflammatory effects.
Example 6
Determination of Anti-Inflammatory Effect Through Measurement of Inflammation-Associated Cytokine mRNA Levels
[0175] In order to determine anti-inflammatory effect of the Stauntonia Hexaphylla fruit hot water extract prepared in Example 1, variation in mRNA content of inflammatory response-associated cytokine was ascertained using macrophage primary cells.
[0176] In order to obtain the macrophage primary cells, 32 4-week male mice (ICR mouse) having a body weight of 15 g to 20 g and 32 Sprague-Dawley mice were obtained from Samtako Inc. (Korea), the respective mice were divided into 16 groups and 4 mice per group were placed and bred. The test animals were bred at a temperature of 20° C. to 24° C. and at a humidity of 60% to 70% under the day-night illumination condition at 12-hour intervals and were freely fed with water and feed. The feed used herein was a solid feed (Samyang Feed Co., Korea). The test animals were bred under the same conditions for 7 days, adapted to laboratory environments and used for further tests.
[0177] Macrophage primary cells (2×10 6 cells/ml) obtained from the test animals were cultured in a serum starvation medium for 24 hours. After culturing, the cells were treated with LPS (0.5 mg/ml), or LPS (0.5 mg/ml) and different concentrations of the Stauntonia Hexaphylla leaf hot water extract and cultured for 24 hours. After 24 hours, RNA was isolated from the cultured cells. The RNA isolation was performed by the following method.
[0178] Specifically, the cultured cells were lysed in a GIT solution (easy BLUE Total RNA extraction kit, Intron Biotechnology Inc., Korea), and centrifuged at room temperature at 10,000 rpm for 5 minutes, and a supernatant was discarded to obtain a pellet. 1 ml of 0.1% DEPC solution (Sigma, USA) was added to the pellet, the resulting mixture was centrifuged at 12,000 rpm for 2 minutes again, and the supernatant was discarded to obtain a pellet. 0.5 ml of guanidinium was added to the obtained pellet, followed by vortexing. Furthermore, 0.5 ml of a phenol/chloroform/iso-amylalcohol mix solution (25:24:1) was added to the resulting mixture, followed by vortexing and centrifugation at 12,000 rpm for 3 minutes to obtain a supernatant. The supernatant was homogeneously mixed with an equal amount of iso-propylalcohol and allowed to stand at −20° C. for 30 minutes. Then, the resulting mixture was centrifuged at 12,000 rpm for 10 minutes, the supernatant was discarded, and the pellet was washed with a 70% aqueous ethanol solution and was dried under vacuum to isolate RNA.
[0179] The isolated RNA was dissolved in 1 ml of a 0.1% DEPC solution and was then used to measure a content of mRNA of inflammation-associated cytokine. The mRNA contents of the inflammation-associated cytokines, IL-1β, IFN-γ and TNF-a, were measured by the following method.
[0180] Superscript II reverse transcriptase (Invitrogen, USA) was added to 3 μg of the isolated RNA, followed by incubation at 42° C. for 105 minutes and then at 70° C. for 15 minutes, to obtain cDNA. The obtained cDNA was quantified by real-time PCR. Primer sequences and test conditions used for the real-time PCR are shown in the following Table 2.
[0000]
TABLE 2
Target
Annealing
mRNA
Primer sequence
Tm (° C.)
TNF-a
Sense
GGCAGGTCTACTTTGGAGTCATTGC
62.2
Anti-
ACATTCGAGGCTCCAGTGAATTCGG
sense
IFN-γ
Sense
GCGGCTGACTGAACTCAGATTGTAG
50
Anti-
GTCACAGTTTTCAGCTGTATAGGG
sense
IL-1β
Sense
TGCAGAGTTCCTACATGGTCAACC
55
Anti-
GTGCTGCCTAATGTCCCCTTGAATC
sense
[0181] As a result of real-time PCR, an image showing comparison of IL-1β, IFN-γ and TNF-a contents with β-actin content is shown in FIG. 8 .
[0182] As shown in FIG. 8 , a control group not treated with LPS did not exhibit mRNAs of inflammation-associated cytokines, IL-1β, IFN-γ and TNF-a, at all, whereas a group treated only with LPS exhibited remarkably high levels of mRNAs of IL-1β, IFN-γ and TNF-a IL-1β. In addition, a group treated with the Stauntonia Hexaphylla fruit hot water extract prepared in Example 1, in spite of treatment with LPS exhibited a concentration-dependent decrease in mRNA contents of IL-1β, IFN-γ and TNF-a, in particular, a prominent decrease in mRNA content of IL-1β.
Example 7
Determination of Anti-Inflammatory Effect Through Measurement of Inflammation-Associated Cytokine, TNF-a, Level
[0183] To ascertain anti-inflammatory effects of the Stauntonia Hexaphylla fruit hot water extract which had been determined to exhibit superior anti-inflammatory effect based on variation in mRNA content of inflammatory response-associated cytokine in Example 6, again, variation in TNF-a among inflammatory response-associated cytokine was confirmed using macrophage primary cells.
[0184] The macrophage primary cells were obtained by breeding test animals in the same manner as in Example 6. Macrophage primary cells (2×10 6 cells/ml) obtained from the test animals were cultured in the same manner as in Example 5. Measurement of amount of produced TNF-a was carried out using an image analysis program (UVIband) supplied from UVITEC fluorescence imaging systems.
[0185] Specifically, TNF-a and β-actin bands separated by agarose gel electrophoresis were image-scanned through the UVITEC fluorescence imaging system. Volumes (intensities) of TNF-a bands and β-actin bands of a normal group, a control group induced by LPS, and experimental groups treated with different concentrations of the Stauntonia Hexaphylla fruit extract were quantified from the scanned images using an image analysis program (UVIband). TNF-a content was determined as a relative content of TNF-a with respect to β-actin expressed in the normal group (relative %, TNF-a/β-actin) and results were shown in FIG. 9 .
[0186] As can be seen from FIG. 9 , a control group not treated with LPS was determined to exhibit a small level of inflammation-associated cytokin, that is, TNF-a, whereas a group treated only with LPS exhibited a remarkably high level of TNF-a. In addition, a group treated with the Stauntonia Hexaphylla fruit hot water extract prepared in Example 1, in spite of treatment with LPS was determined to exhibit a concentration-dependent decrease in TNF-a content.
Example 8
Determination of Inhibitory Effect of Fraction Against COX-2 (cyclooxygenase-2)
[0187] To ascertain anti-inflammatory effect of the fraction of the Stauntonia Hexaphylla leaf hot water extract which had been determined to exhibit superior anti-inflammatory effect based on NO secretion in Example 3 again, inhibitory activity against COX-2 enzyme was confirmed.
[0188] First, 5-week old Sprague-Dawley male white mice (Samtako Inc. Korea) were adapted to laboratory environments for 7 days and used for testing. The test animals were bred at a temperature of 20° C. to 24° C., at a humidity of 60% to 70% under the day-night illumination condition at 12-hour intervals and were freely fed with water and feed. The feed used herein was a solid feed (Samyang Feed Co., Korea). The test animals were bred under the same conditions for 7 days, adapted to laboratory environments and then used for testing.
[0189] The abdomen of the test animals (SD male white mice) was administered with 10 ml of 4% thioglycolate, and abdominal macrophage primary cells were proliferated for 3 days and the mice were cervically dislocated. Abdominal macrophage primary cells were collected from the SD male white mice prepared by cervical dislocation.
[0190] Specifically, after 10 ml of HBSS was added to the abdomen, abdominal macrophage primary cells were collected using a syringe and transferred to a conical tube. The abdominal macrophage primary cells were centrifuged at 13,000 rpm for 5 minutes, washed with a DMEM medium twice, seeded on a petri dish having a diameter of 60 mm and incubated in a CO 2 cell incubator for 4 hours. After incubation, floating cells were removed and adhered cells were stabilized for 24 hours, then proteins were isolated from the cells, which were further used.
[0191] The isolated proteins were treated with 50 mg/ml of the fractions of the Stauntonia Hexaphylla leaf hot water extract obtained in Example 1, stabilized for 30 minutes and cyclooxygenase enzyme activity was measured using a COX fluorescent activity assay kit (Cayman Chemical Company, Item No. 700200). Results of the measured enzyme activity are shown in FIG. 12 .
[0192] As can be seen from FIG. 12 , the water fraction of the Stauntonia Hexaphylla leaf hot water extract did not exhibit any inhibitory effects, and the hexane fraction and the butanol fraction exhibited low inhibitory activity, whereas the ethyl acetate fraction and the chloroform fraction exhibited remarkably superior inhibitory activity. In particular, difference in inhibitory activity was prominent with the passage of time. In particular, the ethyl acetate fraction of the Stauntonia Hexaphylla leaf hot water extract exhibited the most superior COX-2 inhibitory activity.
Example 9
Determination of Antipyretic Effects of Extracts and Fractions
[0193] 9-1. Determination of Antipyretic Effect of Stauntonia Hexaphylla Leaf Extract
[0194] Test animals were used to determine antipyretic effects of the Stauntonia Hexaphylla leaf extract and fractions thereof prepared in Example 1.
[0195] The test animals herein used were 5-week old Sprague-Dawley male white mice obtained from Samtako Inc. (Korea). The test animals were bred at a temperature of 20° C. to 24° C. and at a humidity of 60% to 70% under the day-night illumination condition at 12-hour intervals and were freely fed with water and feed. The feed used herein was a solid feed (Samyang Feed Co., Korea). The test animals were bred under the same conditions for 7 days, adapted to laboratory environments and then used for testing.
[0196] The test of fever induced by lipopolysaccharide (LPS) as a bacterial endotoxin to ascertain antipyretic efficacy using the test animals was carried out using a method suggested by Vilela F C et. al (Anti-inflammatory and antipyretic effects of Sonchus oleraceus in rats. J Ethnopharmacol. 17; 127(3):737-41 (2010)).
[0197] Specifically, 5 mice were randomly selected from the test animals and set as a first group, and 500 μg/kg of lipopolysaccharide (LPS, Sigma, USA) was intraperitoneally injected into the mice to induce fever. Body temperature was measured as follows. Rectal body temperature was measured using a rectal thermometer (Portable Thermocouple Thermometer (Physitemp Instruments, USA) and a stainless steel rectal probe for rats (Physitemp Instruments, USA) and body temperatures of SD mice were measured three times before the test to minimize an temperature increase caused by temperature measurement stress.
[0198] First, in order to determine antipyretic effects of the Stauntonia Hexaphylla leaf hot water extract, a negative control group (LPS) not treated with any sample, a first positive control group (APAP) orally administered with 50 mg/kg of acetaminophen (APAP, Sigma, USA), a conventional drug, found to have antipyretic effect, and a second positive control group (Dexamethasone) orally administered with 1 mg/kg of dexamethasone (Sigma, USA) were used.
[0199] First, 500 μg/kg of a fever-inducing substance (LPS) was intraperitoneally injected (i.p.) into the test animals that finished preparations for minimization of temperature increase caused by temperature measurement stress, and a non-treated group (LPS), a group (SHL-200) orally administered with 200 mg/kg of the Stauntonia Hexaphylla leaf hot water extraction, a group (APAP) orally administered with 50 mg/kg of acetaminophen, and a group (Dexamethasone) orally administered with 1 mg/kg of dexamethasone were prepared according to type of test groups. In addition, 200 mg/kg of the Stauntonia Hexaphylla leaf hot water extract was orally administered one hour after administration of the fever-inducing substance (SHL-200 (1 h)), and rectal temperatures were measured at one hour, 4 hours and 8 hours over 8 hours in total after the administration of the fever-inducing substance. The measurement results are shown in FIG. 12 and the following Table 3. Values of the following Table 3 mean body temperatures (° C.) measured at different times.
[0000]
TABLE 3
Normal
LPS
SHL 200
SHL 200 (1 h)
Dexamethasone
APAP
0 h
37.2
37.2
37.2
37.2
37.2
37.2
1 h
37.55 ± 0.21
38.2 ± 0.68
36.65 ± 0.69
38.23 ± 0.41
37.3 ± 0.52
36.58 ± 0.67
4 h
37.65 ± 0.07
37.85 ± 0.33
37.20 ± 0.45
36.95 ± 0.54
37.6 ± 0.12
37.53 ± 0.59
8 h
37.55 ± 0.07
37.6 ± 0.61
37.7 ± 0.14
37.73 ± 0.22
37.73 ± 0.13
37.78 ± 0.13
[0200] As can be seen from FIG. 13 and Table 3, the group administered with the fever-inducing substance (LPS) exhibited a sharp increase by about 1° C. to 1.8° C. or more, from one hour onwards. However, the group administered with the Stauntonia Hexaphylla leaf hot water extract (SHL-200) according to the present invention exhibited a remarkable decrease in body temperature. This decrease was greater than that of the group (Dexamethasone) orally administered with 1 mg/kg of dexamethasone and was substantially equivalent to that of the group (APAP) orally administered with 50 mg/kg of acetaminophen generally used as an antipyretic drug, which demonstrated that SHL-200 exhibited the superior antipyretic effects. On 4 hours after administration, SHL-200 did not exhibited an increase in body temperature, as compared to the group (APAP) orally administered with 50 mg/kg of acetaminophen, which demonstrated that SHL-200 also exhibited superior persistence.
[0201] In addition, in case of a group (SHL-200(1 h)) orally administered with 200 mg/kg of the Stauntonia Hexaphylla leaf hot water extract at one hour after administration of the fever-inducing substance (LPS), body temperature was sharply increased like the control group and then was considerably decreased and on 4 hours, decreased to a level, similar to the group (APAP) orally administered with the fever-inducing substance and 50 mg/kg of acetaminophen, which demonstrated the Stauntonia Hexaphylla leaf hot water extract exerted effective actions even after fever began, that is, body temperature was elevated to a predetermined level.
[0202] 9-2. Determination of Antipyretic Effect of Fraction of Stauntonia Hexaphylla Leaf Extract
[0203] In order to determine antipyretic effects of the fraction of the Stauntonia Hexaphylla leaf extract prepared in Example 1-2, test animals (5-week old SD male white mice (Samtako Inc., Korea)) bred in the same manner as in Example 9-1 were used.
[0204] Like Example 9-1 to determine antipyretic efficacy using the test animals, LPS-induced fever was carried out using a bacterial endotoxin (Lipopolysaccharide (LPS) from E. coli 0111:B4 (Sigma, USA)) by a method suggested by Vilela F C et. al., and body temperature was measured using a rectal thermometer.
[0205] First, in order to determine antipyretic effects of the Stauntonia Hexaphylla leaf hot water extract, a negative control group (LPS) not administered with any sample, and a positive control group (Ibuprofen) orally administered with ibuprofen (Daewoong Pharmaceutical Co., Ltd., Korea) as a conventional drug known to have antipyretic effect were used. In addition, a hexane fraction (Hx), a chloroform fraction (CHCl 3 ), an ethyl acetate fraction (EA) and a butanol fraction (BuOH) were respectively administered in a dose of 20 mg/kg to experimental groups.
[0206] First, rectal body temperatures of test animals were measured three times using a body thermometer (Portable Thermocouple Thermometer, physitemp, USA) before the test to minimize temperature increase caused by temperature measurement stress.
[0207] The test animals subjected to temperature measurement were orally administered with different contents of respective samples at 5 minutes before administration of the fever-inducing substance, the bacterial endotoxin (LPS), after 5 minutes, 500 μg/kg of the bacterial endotoxin was intraperitoneally injected (i.p.) into the animals, and rectal body temperature of test animals was measured at intervals of 30 minutes for 2 hours. Measurement results are shown in FIG. 14 .
[0208] As can be seen from FIG. 14 , the normal group (Normal) not administered with any sample exhibited almost no variation in body temperature, but the group administered with the fever-inducing substance (LPS) exhibited a sharp increase in body temperature by 1° C. or higher from 30 minutes onward after the administration, maintained the body temperature increased by about 1° C. even at one hour, and exhibited an increase in body temperature by about 0.5° C. even at 2 hours. Meanwhile, when the group administered with the hexane fraction of the Stauntonia Hexaphylla leaf hot water extract was small temperature increment, but exhibited a rather high final temperature at 2 hours, as compared to the group administered with the fever-inducing substance. The butanol fraction exhibited a small temperature increment and an overall low body temperature increase effect, as compared to the hexane fraction. Meanwhile, the group administered with the chloroform fraction exhibited an increase in body temperature in an early stage, but returned to a substantially normal body temperature at 2 hours, which demonstrated that the group administered with the chloroform fraction exhibited inhibitory effect on increase in body temperature, that is, antipyretic effect. The body temperature of the ethyl acetate fraction returned to a normal body temperature at 1 hour, but was lower than an initial temperature at 2 hours. This demonstrated that the ethyl acetate fraction exhibited remarkably superior antipyretic effect comparable to ibuprofen generally used as an antipyretic drug and demonstrated to have antipyretic effects.
[0209] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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Disclosed is an antipyretic drug comprising a Stauntonia Hexaphylla leaf extract as an active ingredient. The antipyretic drug is developed based on the finding that the Stauntonia Hexaphylla leaf extract has no cytotoxicity and exhibits superior antipyretic effects, as compared to conventional antipyretic drugs having antipyretic effects. An antipyretic composition comprising the Stauntonia Hexaphylla leaf extract as an active ingredient exhibits potent antipyretic effect.
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PRIORITY CLAIM
[0001] The present application is a national phase application filed pursuant to 35 USC §371 of International Patent Application Serial No. PCT/FR2009/052371, filed Dec. 2, 2009; which further claims the benefit of French patent application Ser. No. 08/06762 filed Dec. 2, 2008; all of the foregoing applications are incorporated herein by reference in their entireties.
TECHNICAL FIELD
[0002] An embodiment relates to a textile support coated with an elastomeric material for the confection of intercommunication bellows connecting (linking) two compartments of a public transport vehicle (train, subway, tram, bus, plane . . . ) or intercommunication bellows for removable aircraft access ramps. More particularly, an embodiment relates to the use of a coated textile support comprising a double weave fabric both faces of which are coated (covered) with an elastomeric material for the manufacture of intercommunication bellows connecting (linking) two compartments of a public transport vehicle. An embodiment also relates to intercommunication bellows for two compartments of a public transport vehicle or for a removable aircraft-access ramp, characterized in that said bellows comprises a textile support coated with an elastomeric material according to an embodiment, as well as to a method for connecting two compartments of a public transport vehicle comprising the attachment of an intercommunication bellows according to an embodiment between two compartments of the vehicle that are hitched together. An embodiment also relates to a public transport vehicle comprising compartments connected (linked) together by an intercommunication bellows according to an embodiment.
[0003] In the description below, the references between brackets ([ ]) refer to the list of references given after the examples.
BACKGROUND
[0004] Intercommunication bellows connecting (linking) two compartments of a public transport vehicle are typically manufactured with textile supports coated with an elastomeric material in which stiffness for the vertical and horizontal portions of the bellows is sought, the angles (or edges) being achieved with flexible textile supports coated with elastomeric material.
[0005] There are currently two types of bellows on the market for the confection of intercommunication bellows connecting (linking) two compartments of a public transport vehicle: the folded bellows ( FIG. 1A ), and the wavy bellows ( FIG. 1B ).
[0006] An embodiment relates to a coated textile support for the manufacture of bellows where the stiffness of the coated textile support is the most important property to consider.
[0007] Particularly, currently, coated textile supports intended for the manufacture of bellows are manufactured from two textile supports connected together with glue or an elastomeric-based coating, the whole set being coated with an elastomeric material. A schematic illustration of this assembly mode is given in FIG. 2 .
[0008] This construction makes it possible to have a beam effect (i.e., the assembling means is subject to bending similarly to a beam) ensuring stiffness. This assembling mode, however, exhibits the following drawbacks:
Complicated manufacturing method (“Process”), and consequently high manufacturing cost. Limited adhesion between the two textile supports. This limitation in adhesion affects the aging of the product, with in particular a possible detachment of the two fabric layers due to repeated bending.
SUMMARY
[0012] Thus, there is a real need to develop materials which may be used for the manufacture of intercommunication bellows for compartments of public transport vehicles and overcoming the aforementioned faults and drawbacks of the prior art, in particular, materials allowing to fully satisfy the new European Standards as well as the other standards in this range of application, while maintaining the manufacturing costs at a reasonable level and keeping the advantageous mechanical properties of said bellows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 represents two types of intercommunication bellows currently on the market. FIG. 1A : “folded” bellows. FIG. 1B “wavy” bellows.
[0014] FIG. 2 represents a schematic view of the structure of a coated two-ply textile support of the prior art intended for manufacturing bellows.
[0015] FIG. 3 represents a table listing certain properties of the textile fibers available on the market, particularly the mechanical and toxicity properties.
[0016] FIG. 4 represents examples of the junction points of double weave fabrics. The light grey squares represent the locations where the two fabrics making up the double weave fabric are connected via their weft/warp yarns.
[0017] FIG. 5 represents the diagram of a device for determining the stiffness of the coated textile supports according to a flat loop method.
[0018] FIG. 6 represents the diagram of a device for determining the stiffness of the coated textile supports according to a “length deflected under its own weight” method.
[0019] FIG. 7 represents a diagram of coated textile supports, objects of example 4 . FIG. 7A : coated two-ply fabric. FIG. 7B : coated single-ply fabric. FIG. 7C : coated double weave fabric.
[0020] An embodiment aims at providing a textile support coated with an elastomeric material meeting the aforementioned requirements while remaining economically viable. Particularly, an embodiment relates to a double weave fabric coated with an elastomeric material.
[0021] Another embodiment provides an intercommunication bellows for compartments of a public transport vehicle or for a removable aircraft-access ramp, characterized in that said bellows comprises a textile support coated with an elastomeric material comprising a double weave fabric both faces of which are coated with an elastomeric material. The public transport vehicle is advantageously a land transport vehicle, particularly road or rail transport vehicle, such as a train, tram, bus or subway train. The intercommunication bellows may also find applications in the removable access ramps used for the boarding of passengers on jet liners.
[0022] Another embodiment relates to the use of a double weave fabric coated with an elastomeric material for the manufacture of intercommunication bellows for compartments of a public transport vehicle, or for a removable aircraft access ramp.
[0023] In the present document, the expressions “coated textile support” and “textile support coated with an elastomeric material” are used interchangeably.
[0024] The term “elastomeric material” refers to a mixture of one or several elastomers and additives, the latter aiming to allow for the transformation/shaping of the elastomer or mixture of several elastomers, and to attain the desired features of the elastomeric material coating the textile support. These additives may be for example silica, plasticizers, flame retardants, protecting agents and/or cross-linking agents.
[0025] The term “compartments” refers to compartments of possibly different size and shape, and which, during travelling, are imparted a possibly differential movement relating to one or more of the following variables:
[0026] the horizontal and/or vertical inclination with respect to the ground
[0027] the travelling direction, and/or
[0028] the travelling speed
[0029] Thus, an embodiment is a textile support coated with an elastomeric material, and characterized in that it comprises a double weave fabric the two sides of which are coated with an elastomeric material.
[0030] The term “double weave fabric” refers to a textile support composed of two distinct and superposed fabrics which are interwoven together intimately and intermittently at regular spaces by weft yarns of the two fabrics, with the help of the warp yarn. For example, a warp yarn of one of the fabrics may, according to a predetermined sequence, be linked with a weft (or pick) of the other fabric in order to form one single and same fabric. This connection may be achieved according to any type of pattern, typically to form lozenges, squares, rectangles or tubes. The yarns of one of the fabrics participate in the interweaving with the second fabric such that both fabrics composing the double weave fabric are perfectly secured. There are no spaces between the two fabrics composing the double weave fabric. Furthermore, the two fabrics cannot move with respect to each other: we are dealing with one single and same double weave fabric. The number of junction points determines the stiffness of the double weave fabric.
[0031] The double weave fabric of an embodiment is to be distinguished from the double-layer fabric in which two distinct and superposed fabrics are intermittently connected together by a yarn connecting the two fabrics (i.e., that the two fabrics are not fully attached). By way of example of double-wall fabric (or double-stitch fabric), those described in documents DE 40 07 862 (DE' 862) and DE 10 2006 061503 (DE'503), which are incorporated by reference, may be mentioned. In DE' 862, the two fabrics composing the two-ply fabric are connected by elastic strings. In DE'503, a space exists between the two fabrics constituting the double-wall fabric. Thus, the two thicknesses of the fabric in DE'862 and DE'503 are in no way attached, and the resulting double-wall fabric does not have the required stiffness properties (“beam effect”) of the double weave fabric of an embodiment.
[0032] The term “fabric” is to be understood in the conventional sense, i.e., a material obtained through weaving.
[0033] The two aforementioned fabrics making up the double weave fabric may be identical or different.
[0034] The current uses of this type of double weave fabric are for airbags, firemen's clothes (thermal insulation) and furniture fabric (decorative effect from the double weave fabric construction).
[0035] Generally, according to the related art, the inverse and right sides may be reversed with different colors in order to obtain a decorative effect (furniture fabric).
[0036] This double weave fabric is typically achieved in one single operation on a loom.
[0037] With regard to the double weave fabric, the textile yarns may have the following characteristics:
High mechanical properties:
tenacity of approximately 50 to 110 cN/Tex (150.13934-1),
elongation at break higher than approximately 10% (ISO 13934-1). The textile yarns of the double weave fabric may have an elongation at break approximately between 10 and 50%, for example approximately between 10 and 40%, such as approximately between 10% and 30%, approximately between 10 and 25%, and even approximately between 10 and 20% (measured according to the ISO 13934-1 standard).
[0041] The textile yarns connecting the two fabrics are non-elastic yarns.
[0042] For example, the double weave fabric may comprise yarns of
[0043] polyamide, such as polyamide yarns 6 or 66polyester
[0044] m-aramid, such as those available from KERMEL under the same naming, the yarns available under brand name NOMEX® by DUPONT DE NEMOURS and those available under brand name CONEX® by TEIJIN.
[0045] p-aramid, such as those available from DU PONT DE NEMOURS under brand name KEVLAR® or from TEIJIN under brand names TWARON® and TECHNORA®. Such polymers, which thus can be in the form of fibers, yarns or other structures, have made the subject matter of many publications among which U.S. Pat. No. 3,063,966, which is incorporated by reference, may be mentioned.
[0046] vectran HS
[0047] polyimide
[0048] polyamide-imide
[0049] acrylic homopolymers
[0050] oxidized polyacrylonitrile (PAN)
[0051] phenolic
[0052] polybenzimidazole (PBI)
[0053] polyphenylene sulfide (PPS)
[0054] polytetrafluoroethylene (PTFE)
[0055] polyether ether ketone (PEEK)
[0056] polyketone [poly(1-oxotrimethylene)]
[0057] polyphenylsulfone
[0058] or a combination thereof.
[0059] Thus, in an embodiment, the double weave fabric comprises polyamide, polyester, aramid or polyphenylsulfone yarns or a combination of these.
[0060] The double weave fabric comprises polyester yarns.
[0061] In an embodiment, the double weave fabric yarns have a mass per unit length of approximately 500 to 2200 decitex, for example of approximately 600 to 2000 decitex, of approximately 700 to 1800 decitex, of approximately 800 to 1600 decitex, of approximately 900 to 1400 decitex, of approximately 1000 to 1200 decitex. The yarns have a mass per unit length of 1100 decitex.
[0062] In an embodiment, the double weave fabric has a thread count of approximately 8/8 to 11/10 yarns per centimeter, i.e., of approximately 8 to 11 yarns/cm in warp and approximately 8 to 10 yarns/cm in weft. In a particular embodiment, the double weave fabric has a thread count of 8.6/9 yarns per centimeter.
[0063] In an embodiment, the number of junction points of the double weave fabric is of approximately 2 to 20 points/cm 2 , for example of approximately 2 to 16 points/cm 2 , for example of approximately 2 to 8 points per cm 2 . The number of junction points of the double weave fabric is of approximately 4 points/cm 2 , for example approximately 8 points/cm 2 . Examples of junction points are represented in FIG. 4 .
[0064] The number of junction points will be chosen according to the considered use, and in particular to the desired stiffness for the considered application. The higher the number of junction points, the stiffer the coated double weave fabric of an embodiment is. The stiffness may be determined for example by the “flat loop” method, or by the “length deflected under its own weight” method, according to the NF EN 1735 standard, which is incorporated by reference.
[0065] In an embodiment, the double weave fabric comprises polyester yarns having a mass per unit length of approximately 1100 decitex, a thread count of approximately 8.6/9 yarns per centimeter, and a number of junction points of approximately 8 points/cm 2 .
[0066] In an embodiment, the elastomeric material may comprise any elastomer available on the market, particularly those having excellent mechanical and aging properties, adapted to the aforementioned European standards pertaining to the field of intercommunication bellows. To this end, the skilled person can refer to the work “Synthèse, propriétés et technologies des èlastoméres” carried out by the Rubber Formation Institute, (IFOCA, Institut de Formation du Caoutchouc in French) and edited by the French group for the study and application of polymers (groupe français d'études et d'application des polymers, in French) in October 1984, and which work is incorporated by reference.
[0067] For example, the elastomeric material may be:
1) Elastomers for General Use, such as ethylene-propylene-diene terpolymer (EPDM); 2) Elastomers for Specific Uses, such as polychloroprene (CR), a copolymer of hydrogenated acrylic nitrile and butadiene (HNBR), copolymers of ethylene and methyl acrylate or other acrylates (ACM, AEM), polyurethanes (AU, EU); 3) Elastomers for Special Uses, such as polychloroethylene (CM), chlorosulphonated polyethylene (CSM), an epichlorohydrin copolymer (ECO), a heat curable silicon elastomer (EVC), a fluorocarbon elastomer (FPM); or a mixture thereof.
[0072] The elastomeric material may comprise chlorosulphonated polyethylene (CSM) as an elastomer.
[0073] In an embodiment, the elastomeric material may comprise the chlorosulphonated polyethylene as an elastomer, and the double weave fabric comprises polyester yarns of mass per unit length of approximately 1100 decitex, has a thread count of approximately 8.6/9 yarns per centimeter (i.e., approximately 8.6 yarns/cm in warp and approximately 9 yarns/cm in weft), and has a number of junction points of approximately 8 points/cm 2 .
[0074] The elastomer may be linear or branched, and may be heat curable.
[0075] The elastomeric material may contain fillers, such as for example silica, plasticizers, flame retardants (hydrated alumina), protecting agents, and/or cross-linking agents. These additives aim to attain the desired properties of the elastomeric material, and to allow for the transformation/shaping of the elastomer or of the mixture of elastomers that have been used.
[0076] According to an embodiment, the total weight of the coated textile support ranges approximately between 600 and 4400 g/m 2 , for example approximately between 1000 and 3000 g/m 2 , for example approximately 1200 g/m 2 . It is understood that the total weight of the coated textile support may be adapted to the order, i.e., according to the application. Typically, the total weight of the coated textile support may be adapted to any required value approximately between 1000 and 3000 g/m 2 .
[0077] According to a particular embodiment, the tenacity of the fiber of the double weave fabric is higher than or equal to approximately 50 cN/Tex (ISO 13934-1) and its elongation at break higher than or equal to approximately 10% (ISO 13934-1). The fiber of the double weave fabric may have an elongation at break approximately between 10 and 50%, for example approximately between 10 and 40%, for example approximately between 10 and 30%, approximately between 10 and 25%, and even approximately between 10 and 20% (measured according to the ISO 13934-1 standard, which is incorporated by reference).
[0078] When the coated textile supports according to an embodiment are used for intercommunication bellows for compartments of railroad vehicles, they should notably meet the European Standard project: TS EN 45545-2, which specifically provides for protective measures against fires in railroad vehicles, and in particular fire safety requirements for the design of railroad vehicles, and which is incorporated by reference.
[0079] With regard to this issue, the harmonization of European standards has lead to a homogenization based on the highest requirements, particularly on the criteria pertaining to fire, the obscuration of smoke and the toxicity of emission gases, the mechanical and ageing requirements remaining unchanged.
[0080] To this, are added new environmental constraints.
[0081] Thus, according to the new standards, the combustion of the material constituting public transport vehicles (e.g. the intercommunication bellows) must be carried out (i) with a minimum flame, (ii) with a reduced obscuration of smoke and (iii) by emitting the minimum of toxic products.
[0082] The coated textile supports according to an embodiment may also meet other standards than those aforementioned, particularly those in force outside Europe, depending on the related country and of the use of the intercommunication bellows (type of public transport vehicle, or removable aircraft-access ramp).
[0083] Consequently, according to the regulations in force, the composition of the textile supports coated with an elastomeric material constituting the intercommunication bellows may also meet the following three main constraints:
[0084] mechanical constraints: the bellows must have a certain tensile strength, tear strength, and repeated bending strength.
[0085] ageing constraints: the bellows have a long lifespan (higher than 10 years) and must thus be particularly resistant to climatic (UV, ozone, heat, cold, rain . . . ) and chemical (acids, solvents, greases, oils, . . . ) strains.
[0086] fire constraints: in the event of fire, the bellows must resist the fire and emit minimum smoke with minimum toxicity.
[0087] Thus, when it is required, or when the regulations in force require it, the double weave fabric may be made of heat and combustion resistant textile materials.
[0088] For example, the elastomeric material coating the double weave fabric may have an excellent ageing with regard to bad weather and a low combustibility. The elastomeric material may also have a reduced obscuration of smoke. In a particular embodiment, the elastomer or the mixture of elastomers used in the elastomeric material will not contain any halogens or will contain very few. For example, the elastomeric material may comprise heat curable silicone as an elastomer.
[0089] When it is desired (for example when the regulations in force require it), the textile yarns may also have combustion strength; for example, the product does not catch fire easily or does not catch fire at all. In an embodiment, the textile yarns of the double weave fabric may also be such that their combustion gases are not or hardly toxic and without significant smoke.
[0090] In an embodiment, textile yarns of the double weave fabric will also have an economically reasonable price.
[0091] FIG. 3 gives the range of values of the aforementioned properties for certain textile fibers available on the market. The reader may refer to it in order to select the type of fiber for a particular use with the required mechanical performances, combustion strength and price. It is worth noting that glass, of low cost is not convenient as its lack of elongation at break (3 to 4%) makes it breakable with the repeated bending.
[0092] When it is desired, or when the regulations in force require it, the coated textile support according to an embodiment may exhibit one or several of the following properties (advantageously the four):
[0093] (i) fire resistance
[0094] (ii) auto-extinction
[0095] (iii) does not support combustion
[0096] (iv) is not fumigant
[0097] Thus, according to an embodiment, the elastomeric material covering the coated textile support may comprise an additive selected from the group comprising the additives which improve adhesiveness, durability and/or fire resistance
[0098] According to an embodiment, the coated textile support comprises a quantity in weight of toxic products less than approximately 8% with respect to the total weight of said coated textile support, said toxic products are selected from the group comprising phthalates, heavy metals, halogens, or a mixture of these. According to a particular embodiment, the coated textile support comprises a quantity in weight of said toxic products less than approximately 7%, 6%, 5%, 4%, 3%, 2%, 1% with respect to the total weight of said coated textile support.
[0099] According to an embodiment, the coated textile support is not fumigant. The term “is not fumigant” refers to emitting none or hardly any smoke during its combustion, for example emitting approximately 50% less smoke, or even approximately 60% less smoke, or even approximately 70% less smoke, or even approximately 75% less smoke, or even approximately 80% less smoke, or even approximately 85% less smoke, or even approximately 90% less smoke, or even approximately 95% less smoke, with respect to the composite products of the prior art (for example those aforementioned).
[0100] According to a particular embodiment, the coated textile support does not (or hardly) emit(s) toxic gases during its combustion. For example the coated textile support emits approximately between 50 and 95% less toxic gases in volume with respect to the composite products of the prior art, the volume being measured in approximately identical temperature and pressure conditions. By way of example, toxic gases are selected from the group comprising hydrocyanic acid (HCN), NOx, halogens or a mixture of these.
[0101] Concerning the manufacture of the coated textile support according an embodiment, the deposit of the elastomeric material on the textile support may be achieved either by coating or by calendering, or by flat die extrusion.
[0102] Depending on the desired weight of the coated textile support, several layers of elastomeric material may be deposited.
[0103] The mode of deposit by coating makes it possible to obtain a relatively low weight of elastomeric material (approximately between 15% and 50 g/m 2 per layer) with great uniformity.
[0104] The mode of deposit by calendering makes it possible to obtain more important weights ranging approximately from 100 to 1000 g/m 2 per successive layer.
[0105] The mode of deposit by flat die extrusion makes it possible to obtain weights ranging approximately from 150 to 1500 g/m 2 in one single layer.
[0106] Thus, in a particular embodiment, the coated textile support may be manufactured by coating, calendering or by flat die extrusion. More particularly, the coated textile support according to an embodiment may be manufactured by calendering of an elastomeric material and a double weave fabric that has been adherized beforehand or not on both sides with glue.
[0107] According to a particular embodiment, the double weave fabric may have received, beforehand, a deposit of adhesive paste (notably glue) to allow for a good adhesion of the double weave fabric and the elastomeric material.
[0108] The adhesive paste may contain as constituent, for example glue in the form of a paste. The adhesive paste may be prepared according to good engineering practice. Particularly, it may be solvent-based or water-based (latex), it may be of function of the type of elastomer(s) used, of the fabric to make adhere, of the evaporation system used, as well as other considerations pertaining to the environment.
[0109] In a particular embodiment, the adhesive paste is spread on both sides of the double weave fabric. Within the scope of this embodiment, the adherization may be achieved by coating (doctor blades, cylinders or plastic curves) or by impregnation (dip and possibly hydroextraction). In the case of an adherization by coating, the adhesive paste may be the same or different on each side of the double weave fabric. In a particular embodiment, specifically when the adherization is achieved by impregnation, the adhesive paste is the same on each side of the double weave fabric.
[0110] The thickness of the adhesive paste may be the same or different on each side of the double weave fabric. In a particular embodiment, the thickness of the adhesive paste is substantially the same on each side of the double weave fabric. For example, the adhesive paste is coated or impregnated with a thickness approximately of 15 to 60 g/m 2 .
[0111] The adhesive paste is submitted to a drying operation in order to remove the solvents or the water, and dry the adhesive paste before the deposit of the elastomeric material.
[0112] In certain particular embodiments, the drying temperature ranges approximately between 80 and 170° C., according to the solvents used. The drying times are function of the length of the drying tunnel used. Usually, this time ranges approximately between 1 and 2 minutes.
[0113] In certain particular embodiments, the deposit of the elastomeric material on the double weave fabric thus adherized is carried out by calendering.
[0114] Once the double weave fabric coated with elastomeric material, it is subjected to a step of curing/cross-linking.
[0115] An embodiment relates to the use of a coated textile support for manufacturing intercommunication bellows for public transport vehicle compartments, or for a removable aircraft-access ramp. More particularly, the coated textile support of an embodiment comes into play in the manufacture of intercommunication bellows connecting (linking) two compartments of a public land transport vehicle, particularly road or railroad. For example, the coated textile support of an embodiment is used for the manufacture of intercommunication bellows connecting (linking) two compartments of a train, subway, tramway, and/or bus.
[0116] An embodiment also relates to a double weave fabric for manufacturing intercommunication bellows connecting (linking) two compartments of a public transport vehicle, or intercommunication bellows for a removable aircraft-access ramp.
[0117] Another embodiment relates to intercommunication bellows of compartments for a public transport vehicle or for a removable aircraft-access ramp, said bellows comprising a coated textile support. More particularly, the intercommunication bellows connects (links) two compartments of a public land transport vehicle, particularly road or railroad. For example the intercommunication bellows connect (link) two compartments of a train, subway, tramway and/or bus.
[0118] According to an embodiment, it is provided an intercommunication bellows for compartments of a public transport vehicle or for a removable aircraft-access ramp, characterized in that said bellows is formed from a textile support coated with elastomeric material comprising a double weave fabric both faces of which are coated with an elastomeric material, said coated textile support having a stiffness approximately of 58 to 70 mm in the longitudinal and transversal direction according to the NF EN 1735 standard, which is incorporated by reference.
[0119] Methods for manufacturing bellows from coated textile supports are well known.
[0120] For example, if the coated textile support is cured, the bellows may be prepared by stitching with deposit of glue or a protective product making it possible to protect the stitch yarn and seal the pipe seams (holes formed by the stitching needle). The glue or the protective product may also make it possible to waterproof the bellows.
[0121] If the coated textile support is not cured, the bellows can be prepared by depositing the coated textile support in a mold of the desired shape. Then, an open cure and a hot cure are carried out. One may adapt these methods to the manufacture of intercommunication bellows according to an embodiment.
[0122] Another embodiment relates to a method of connecting (linking) two compartments of a public transport vehicle comprising a step of attaching the ends of an intercommunication bellows on the facing front sides of the two compartments of said public transport vehicle. An end of the bellows is attached to a front side of a first compartment. The other end of the bellows is attached on the front side of the second compartment facing the first compartment. The ends of the intercommunication bellows may be attached to the two compartments by means of frames having the shape of the front sides of the compartments to be connected or linked together. The intercommunication bellows thus surrounds the passage openings provided between the compartments, thus allowing for the circulation of passengers from one compartment to the next without being exposed to the external environment.
[0123] When the connection (linking) between the vehicle compartments comprises a rotating tray for forming an articulation of the two compartments (allowing for sharp turns), the intercommunication bellows of the attaching means may also be provided on the rotating tray.
[0124] These are most conventional attaching techniques which the skilled person will know how to select the according to the type of vehicle and the shape of the compartments to connect (link).
[0125] Another embodiment relates to a public transport vehicle comprising compartments connected (linked) to each other by intercommunication bellows. Intercommunication bellows for land vehicles (particularly road or railroad), as well as their setting up in these vehicles to ensure the intercommunication (or the intercirculation) between two successive compartments of the vehicle, are well known. It is one of the most classic techniques known to adapt these methods on installing an intercommunication bellows in the targeted public transport vehicles.
[0126] In embodiments described in the present document, the public transport vehicle may be, for example, a land transport vehicle (particularly road or railroad). For example, it can be a train, a subway train, a tramway and/or a bus.
[0127] In embodiments described in the present document, the intercommunication bellows may be a folded or wavy bellows.
[0128] Thus, the textile support coated with an elastomeric material according to an embodiment has the required stiffness to allow for the manufacture of intercommunication bellows for public transport vehicles (particularly trains). This stiffness is ensured by the structure itself of the double weave fabric.
[0129] On the other hand, the mechanical connection of the two textile layers of double weave fabric is highly increased (see Example 1). This feature makes it possible to considerably reduce the detachment caused by the repeated bending. By way of example, the adhesion measures by peel according to ISO 2411, which is incorporated by reference, standard for the classic coated textile supports (i.e., two fabrics glued together, the whole coated with an elastomeric material) are approximately of 10 to 15 daN/5 cm. In contrast, the double weave fabric coated with an elastomeric material according to an embodiment has a peel adhesion higher than or equal approximately to 20 daN/5 cm (particularly for those carried out from double weave fabric of approximately 4 points/cm 2 .), or even higher than or equal approximately to 30 daN/5 cm (particularly for those carried out from double weave fabric of approximately 8 points/cm 2 .), or even difficult to determine (which tends to indicate that the double weave fabric coated with elastomeric material according to an embodiment is difficult to delaminate, or even non-delaminatable). The double weave fabric coated with elastomeric material according to an embodiment thus offers a delamination strength well higher than the classically coated textile supports of the prior art.
[0130] Furthermore, the tear strength of the double weave fabric coated with elastomeric material is also highly increased (see Example 1). Thus, the double weave fabric coated with elastomeric material according to an embodiment has a tear strength well higher than the classically coated textile supports of the prior art: higher than or equal to approximately 40 daN versus approximately 15 to 20 daN, respectively (ISO 4674-1 standard, method B (tearing of trousers in one single scrape)).
[0131] Moreover, the double weave fabric coated with elastomeric material according to an embodiment totally eliminates the recourse to glue or elastomer-based coating of the coated textile supports of the prior art ( FIG. 2 ), which aims to ensure the adhesion between the two textile supports in the materials intended for manufacturing bellows. Here, no glue or elastomer-based coating is necessary. The adhesion of the two textile fabrics is ensured by the structure itself of the double weave fabric. Consequently there are three noteworthy advantages:
[0132] there is no possible detachment as the double weave fabric is attached and behaves as one and the same fabric. The drawback of the detachment caused by the repeated bending is thus eliminated.
[0133] the weight of the final coated textile support is thus lessened (the glue/linking coating is removed) without however affecting the mechanical and stiffness properties of the end product
[0134] on the contrary, the quantity of glue/elastomer-based coating used in the conventional two-ply materials ( FIG. 2 ) may be removed in favor of an equivalent quantity of elastomeric material coating both sides of the double weave fabric. Thus, with equal weight, the coated textile support according to an embodiment is endowed with better ageing properties with respect to the materials currently available on the market (more coating of elastomeric material while maintaining the same weight).
[0135] Furthermore, the manufacturing process of the coated textile support according to an embodiment is simplified as there is no more deposit of glue between the two fabrics. This deposits requires 6 passages through the machine (an impregnation and two coatings per fabric), whereas with a double weave fabric, it is reduced to 1 passage (one impregnation).
[0136] An embodiment is thus remarkable in so far as it constitutes a viable alternative solution to the coated textile supports currently on the market, intended for the manufacture of intercommunication bellows. An embodiment particularly allows for the manufacture of intercommunication bellows connecting (linking) the compartments of public transport vehicles, which have the required mechanical properties for this type of application (i.e., stiffness (“beam effect”), and tear and delamination strength), while keeping the manufacturing costs at a reasonable level.
[0137] The contents of the protocols relative to international (ISO), French and European (NF, EN) standards, mentioned in the present document is incorporated by reference in the present document in its entirety. These protocols are on sale to the public on the AFNOR website (http://www.boutique.afnor.org), which is incorporated by reference.
[0138] Features and advantages of one or more embodiments will become apparent upon reading the examples below, illustrated by the accompanying drawings.
DETAILED DESCRIPTION
Examples
Example 1
Preparation of a Double Weave Fabric Coated with an Elastomeric Material by Calendering
a) Double Weave Fabric
[0139] The double weave fabric is composed of 2 fabrics made up of high tenacity polyester yarns having a mass per unit length of 1100 decitex and a thread count of 8.6/9 yarns per centimeter (i.e., 8.6 yarns per centimeter in the warp direction, and 9 yarns per centimeter in the weft direction).
[0140] The link between the two layers of fabric is ensured by junction points spaced apart by 5 mm in warp and in weft; i.e., 8 junction points per cm 2 (see FIG. 4 ).
b) Elastomer
[0141] The elastomeric material is a chlorosulphonated polyethylene-based (CSM) based elastomer. It may be obtained from Dupont Performance Elastomère (USA) “Hypalon®”, Tosoh (Japan) “Toso CSM®” or Jining (China).
c) Coating
[0142] The elastomeric material is arranged on the double weave fabric by calendering according to the following method:
[0143] Before the deposit of the elastomeric material, 60 to 70 g/m 2 of adhesive paste is deposited on both sides of the double weave fabric. This paste is deposited using the impregnation technique. This paste is a composition having a dry matter of 30%.
[0144] A drying operation is then carried out to dry this adhesive paste and remove the solvents (toluene and methyl ethyl ketone (MEC)), at a temperature higher than 160° C.
[0145] The deposit of elastomeric material on the adherized double weave fabric is carried out by calendering on each of the two sides of the textile (one layer per side).
d) Curing
[0146] After deposit of the elastomeric material, a thermal treatment is carried out for the cross-linking. It is carried out continuously on a machine and under pressure. The temperature ranges between 180 and 185° C., for example 183° C.
e) Properties
[0147] The total weight of the double weave fabric coated with the thus obtained elastomeric material is of 1200 g/m 2 .
[0148] Three important characteristics of this coated fabric are the following:
[0149] Stiffness: determination of the stiffness according to the NF EN 1735 standard: 58 to 70 mm in the longitudinal and transversal direction in the warp and weft direction (method called “flat loop”)
[0150] Tear strength: trouser tear according to ISO 4674-1, standard method B (which is incorporated by reference): 40 to 50 daN.
[0151] Delamination strength between the 2 layers of fabric: peel adhesion according to ISO 2411 standard (which is incorporated by reference): 20 to 30 daN/5 cm.
Example 2
Preparation of a Double Weave Fabric Coated with an Elastomeric Material by Flat Die Extrusion
[0152] The operating process is the same as that of the calendering method of example 1 (i.e., with prior adhesion). The calender is replaced by a flat die extruder. The deposit may go from 100 to 1500 g/m 2 but in one single operation (monolayer).
Example 3
Methods for Determining the Stiffness of a Double Weave Fabric Coated with an Elastomeric Material According to an Embodiment
[0153] The stiffness (or on the contrary the suppleness) of a coated double weave fabric according to an embodiment may be determined according to the European and French NF EN 1735 standard, which is incorporated by reference.
[0154] Two methods are available according to the aforesaid standard.
Flat Loop Method
[0155] The principle is as follows: the loop is shaped on a rectangular strip of the coated textile support, placed on a horizontal plane, by superposing the two ends which are then connected together under a steel bar. The height of the loop is measured. The suppleness is characterized by the height of the loop: the smaller the height of the loop, the greater the suppleness. Inversely, the greater the height of the loop, the greater the stiffness.
[0156] The test apparatus is typically composed of the following parts (see FIG. 5 ):
[0157] a flat rectangular plank provided with, near one of its ends, with a shoulder whereof the side is perpendicular to the axis of the plank (the dimensions indicated on FIG. 5 are given by way of example; they may be increased to allow for the attaching of several specimens on the same plank).
[0158] a stainless steel bar of around 200 mm in length and of square section of around 20 mm on the side.
[0159] a millimeter graduated ruler.
[0160] As a general rule, the temperature of the specimens (tested samples) highly influences the suppleness value. Thus, it may be necessary to condition the latter during at least 24 hours in one of the normal atmospheres of EN ISO 2231 (which is incorporated by reference) and to carry out the tests in the same atmosphere. In order to prevent any deformation of the specimens, the conditioning must be achieved on a horizontal surface, the side which must form the outside of the loop being turned upwards.
[0161] The specimen has the shape of a rectangle of 600 mm+/−5 mm in length and of 100 mm+/− in width.
[0162] Three cut out specimens in the longitudinal direction and three cut out specimens in the transversal direction of the coated textile support are used to test.
[0163] The sampling is typically taken from the useful width of the roller according to the ISO 2286-1 standard, which is incorporated by reference.
[0164] The surface of the plank is powdered uniformly with zinc stearate or talc powder. By holding the ends of the specimen between one's fingers, the latter is placed on the plank such as one of its sides rest on the plank and that one end is pressed against the shoulder (the choice of the side to use depends on the destination of the product. The test may also be carried out again after having tipped the specimen on the opposite side).
[0165] The other end is connected to the first such as to form a loop, by also pressing it against the shoulder.
[0166] The steel bar is placed in position on the two superposed ends. The specimen is maintained in this position during 5 minutes+/−0.5 minute.
[0167] On each specimen, is measured, using the graduated ruler, the maximum heights with respect to the plank from the two edges of the loop (three specimens cut out in the longitudinal direction and three in the transversal direction). Thus, there are two values per specimen, and twelve values in all.
[0168] The suppleness is given by the arithmetic mean of the six values obtained in the longitudinal direction and the six values obtained in the transversal direction.
[0169] Method of the length deflected under its own weight (“longueur fléchie sous son poids” in French)
[0170] The principle is as follows: a rectangular strip of coated textile support is placed on a horizontal platform. When the strip is moved on the platform, the end leaves the platform, then bends under its own weight. When the strip is sufficiently advanced, the end touches an inclined plane. The bending length is the length of the specimen between the edge of the platform and the point 0 of the ruler. This length is given by direct reading of the ruler if there was no sliding.
[0171] The test apparatus is typically composed of the following parts (see FIG. 6 ):
[0172] a horizontal platform P treated on its upper surface to allow for the easy sliding of the specimen
[0173] a stiff graduated ruler S (a metal piece of around 25 mm wide is suitable). The lower side of the ruler S is covered with a material that has a high friction coefficient (rubber paper for example) such as when the ruler S is made to advance, it drags forward the specimen placed between the ruler and the platform P
[0174] an inclined plane forming an angle of 41° 30′+/−30′ under the horizontal (the measure range depends on the size of the device).
[0175] As for the flat loop method, the temperature of the specimens highly influences the suppleness value. Thus, it may be necessary to condition these during at least 24 hours in one of the normal atmosphere of the EN ISO 2231 (which is incorporated by reference) and to carry out the tests in the same atmosphere. In order to prevent any deformation of the specimens, the conditioning must be achieved on a horizontal surface, the side which should be upward on the flexometer being turned upwards.
[0176] The specimen has the shape of a rectangle of 25 mm+/−1 mm wide and a length such that it allows for the determination of the length of bending. A length of 200 mm is usually sufficient.
[0177] 10 specimens are usually used cutout in the longitudinal direction and 10 specimens cut out in the transversal direction.
[0178] The sampling is typically taken from the useful width of the roller according to the ISO 2286-1 standard, which is incorporated by reference.
[0179] The flexometer is placed on a level table. The specimen is placed between the platform P and the ruler S such that the line D, the 0 of the graduated ruler, and the end of the specimen coincide. The ruler is pushed so that the end of the specimen advances over the inclined plane, bends under the force of its own weight and comes to touch the inclined plane. The test lasts around 10 seconds.
[0180] The bending length is the length of the specimen between the edge of the platform and the point 0 of the ruler. This length is given by directly reading the ruler if no sliding has occurred.
[0181] The test is repeated on other specimens by changing the side in contact with the platform.
[0182] The bending lengths are measured separately in the longitudinal direction then in the transversal direction on each side.
[0183] For each measurement, there are five specimens. The result is the arithmetic mean of the five measurements carried out in centimeters.
Example 4
Examples Comparing the Stiffness of Coated Textile Supports
[0184] The stiffness of the three types of coated textile supports is measured according to the flat loop method described in Example 3 above.
[0185] The coated textile supports are illustrated in FIG. 7
[0186] The results are listed in the table below:
[0000]
Stiffness (mm) in the
Type of coated textile
longitudinal direction
Two-ply polyester fabric coated with
60
chlorosulphonated polyethylene-based
elastomeric material (CSM or
Hypalon ®)
single-ply polyester fabric coated with
50
chlorosulphonated polyethylene-based
elastomeric material (CSM or
Hypalon ®)
Double weave polyester fabric coated with
60
chlorosulphonated polyethylene-based
elastomeric material (CSM or
Hypalon ®)
[0187] The coated double weave fabric according to an embodiment is much stiffer than its single-ply homologue and as efficient in stiffness as the coated two-ply.
[0188] Thus, the coated double weave fabric according to an embodiment may be more advantageous than the coated textile supports that are currently used for the manufacture of intercommunication bellows for public transport vehicles, as it has the advantages of two-ply textile supports in terms of stiffness, without the drawbacks (bad tear and delamination strengths). Moreover, the double weave fabric coated according to an embodiment is less expensive.
[0189] From the foregoing it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. Furthermore, where an alternative is disclosed for a particular embodiment, this alternative may also apply to other embodiments even if not specifically stated.
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An embodiment relates to an intercommunication bellows for compartments of a public transport vehicle or for a removable aircraft-access ramp, formed from a coated textile support, comprising a double weave fabric both faces of which are coated with an elastomeric material, and to a method of connecting two compartments of a public transport vehicle comprising the attachment of an intercommunication bellows between two compartments of the vehicle that are hitched together. An embodiment also relates to a public transport vehicle comprising compartments connected together by an intercommunication bellows. According to an embodiment, the double weave fabric coated with an elastomeric material has one or more of the following properties: stiffness; delamination resistance; tear resistance.
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REFERENCE TO PRIORITY DOCUMENT
[0001] This application claims priority of co-pending U.S. Provisional Patent Application Ser. No. 61/210,581 filed Mar. 19, 2009. Priority of the aforementioned filing date is hereby claimed and the disclosure of the Provisional patent application is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates to devices and methods that permit fixation and stabilization of the bony elements of the skeleton of a patient. The devices permit adjustment and maintenance of the spatial relationship(s) between neighboring bones. Depending on the specifics of the embodiment design, the motion between adjacent skeletal segments may be limited or completely eliminated.
[0003] Spinal degeneration is an unavoidable consequence of aging and the disability produced by the aging spine has emerged as a major health problem in the industrialized world. Alterations in the anatomical alignment and physiologic motion that normally exists between adjacent spinal vertebrae can cause significant pain, deformity, weakness, and catastrophic neurological dysfunction.
[0004] Surgical decompression of the neural tissues and immobilization of the vertebral bones is a common option for the treatment of spinal disease. Currently, vertebral fixation is most frequently accomplished by anchoring bone screws into the pedicle portion of each vertebral body and then connecting the various screw fasteners with an interconnecting rod. Subsequent rigid immobilization of the screw/rod construct produces rigid fixation of the attached bones.
[0005] A shortcoming of the traditional rod/screw implant is the large surgical dissection required to provide adequate exposure for instrumentation placement. The size of the dissection site produces unintended damage to the muscle layers and otherwise healthy tissues that surround the diseased spine. A less invasive spinal fixation implant would advantageously minimize the damage produced by the surgical exposure of the spine.
[0006] In U.S. Pat. No. 7,048,736, Robinson et al teach the use of interspinous process plate to fixate adjacent vertebrae. As disclosed, the device is used to supplement orthopedic implant and/or bone graft material placed into the intervertebral disc between the attached vertebra. Thus the device functions to immobilize the vertebrae until bone fusion occurs but, in itself, does not provide a compartment for bone graft placement within the posterior aspect of the spine. Since bone graft material must be placed in order to achieve vertebral fusion, the device must be used in conjunction with bone graft material that is placed at a secondary site of the attached vertebra bones, such as within the disc space, between adjacent transverse processes, and the like. This is a significant disadvantage and prevents use of the Robinson device by itself to both immobilize and fuse the vertebral bones.
[0007] The growing experience with spinal fusion has shed light on the long-term consequences of vertebral immobilization. It is now accepted that fusion of a specific spinal level will increase the load on, and the rate of degeneration of, the spinal segments immediately above and below the fused level. As the number of spinal fusion operations have increased, so have the number of patients who require extension of their fusion to the adjacent, degenerating levels. The rigidity of the spinal fixation method has been shown to correlate with the rate of the degenerative progression of the adjacent segments. In specific, implantation of stiffer instrumentation, such as rod/screw implants, produced a more rapid progression of the degeneration disease at the adjacent segment than use of a less stiff fixation implant.
SUMMARY
[0008] This application discloses several exemplary devices that attach onto the spinous processes of adjacent vertebrae and address the limitation and shortcomings of prior devices and methods. In one embodiment, a device comprises an implant immobilizes the attached vertebrae through a minimally invasive surgical approach while providing a compartment within the implant for the placement of bone graft or bone graft substitute. The bone graft material then fuses the spinous processes and/or lamina portion of bone of the vertebral bone to which the device is attached. In another embodiment, the implant permits movement of the attached bone within a defined range of motion. The device is capable of preventing aberrant anterior and/or posterior spondylolisthesis as well as limiting the extent of flexion, extension, lateral flexion and rotation of the attached vertebral. Spinous process fixation provides good segmental immobilization through a minimally invasive surgical approach.
[0009] In other exemplary embodiments, the implant is anchored to the pedicle portion of at least one vertebral bone to provide superior bone fixation. In another embodiment, a bone anchor is placed through the pedicle of the inferior vertebra, across the disc space above the inferior vertebra, and into the lower boney surface of the upper vertebral bone. The implant employs a fastener that can be placed as free-standing device, or it can then be anchored to or interconnected with a fixation device that is anchored onto at least one spinous process. Further, a fastener may be used in this way through each of the two pedicles that are located on each side of the vertebral midline.
[0010] In another embodiment, an implant or orthopedic device is adapted to fixate the spinous processes of vertebral bones. The implant includes at least one bone engagement or abutment member located on each side of a spinous process of a first vertebra and a second vertebra, wherein the abutment members are adapted to forcibly abut the side of each spinous process. The implant has a locking mechanism that is adapted to rigidly immobilize at least a first abutment member on one side of the spinous process with at least a second abutment member on the other side of the spinous process (i.e., across the vertebral midline in the mid-sagittal plane from the first abutment member) using an interconnecting member (such as, for example, a rod, plate, etc) that crosses the vertebral midline. The locking mechanism is capable of reversibly transitioning between a first state, wherein the orientation between at least one abutment member and the interconnecting member is changeable in at least one plane and a second state, wherein the orientation between at least one abutment member and the interconnecting member is rigidly affixed. The implant further includes a compartment within at least one abutment member that is adapted to contain bone graft material, which can be bone graft, bone graft substitute, or a combination thereof.
[0011] In an aspect, there is disclosed an orthopedic implant for the fusion of adjacent bony segment. The implant comprises a first member and a second member opposed to the first member, wherein the first and second member define a space therebetween sized to receive a bone. The first and second members have opposed surfaces each surface having at least one spiked protrusion for capturing a bone therebetween. At least one of the members defines an internal compartment adapted to contain a bone graft material, the compartment communicating with at least one bore hole in the at least one member for communicating the bone graft material with the captured bone. The bone graft material in the compartment extends from a first side of the first captured bone to a first side of a second captured bone, wherein the first side of the first and second captured bones are also the sides penetrated by the spike protrusions.
[0012] Multiple additional embodiments are described herein. Other features and advantages should be apparent from the following description of various embodiments, which illustrate, by way of example, the principles of the disclosed devices and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates perspective and orthogonal views of a pair of vertebral bones.
[0014] FIG. 2 shows a perspective view of a bone implant system in a completely assembled state
[0015] FIG. 3 shows the system with an interconnecting rod detached.
[0016] FIG. 4 shows the system in an exploded state
[0017] FIG. 5 shows various orthogonal views of an exemplary body member of the system.
[0018] FIGS. 6A and 6B show plan views of the body member.
[0019] FIG. 7 shows perspective views of a locking member of the system.
[0020] FIG. 8 show orthogonal views of the locking member.
[0021] FIGS. 9A and 9B shows an embodiment of the system including a rod with spherical ends.
[0022] FIG. 10 shows a method of implanting and using the system 105 .
[0023] FIG. 11 shows the system in an implanted state.
[0024] FIG. 12A shows an embodiment of an assembled bone screw assembly.
[0025] FIG. 12B shows the bone screw assembly in an exploded state.
[0026] FIGS. 13A , 13 B, 14 , and 15 show a method and device for using the bone implant system with one or more bone screw assemblies.
[0027] FIG. 16 shows use of the system wherein one vertebral bone does not have a spinous process that will permit device fixation.
[0028] FIGS. 17A and 17B show an additional embodiment of the system 105 that may be used with a bone screw.
[0029] FIG. 18 illustrates an embodiment wherein a fastener is positioned through the pedicle of the inferior vertebra V1, across the disc space between the two vertebrae and into the inferior aspect of the upper vertebra.
[0030] FIGS. 19A-19C show an exemplary embodiment of the fastener of FIG. 18 .
[0031] FIG. 20 shows the fastener in an implanted state.
[0032] FIG. 21 shows the fastener and the system in an implanted state.
DETAILED DESCRIPTION
[0033] In order to promote an understanding of the principals of the disclosure, reference is made to the drawings and the embodiments illustrated therein. Nevertheless, it will be understood that the drawings are illustrative and no limitation of the scope of the invention is thereby intended. Any such alterations and further modifications in the illustrated embodiments, and any such further applications of the principles of the invention as illustrated herein are contemplated as would normally occur to one of ordinary skill in the art.
[0034] FIG. 1 illustrates perspective and orthogonal views of a pair of vertebral bones. The vertebrae are represented schematically and those skilled in the art will appreciate that actual vertebral bones may contain features that are not depicted in FIG. 1 .
[0035] FIG. 2 shows a perspective view of a bone implant system 105 in an assembled state. The system 105 includes several components, including at least two body members 110 and an elongated interconnecting member, such as a rod 112 or plate, that interconnects the body members 110 in a spaced relationship with the space between the body members 110 sized and shaped to receive a portion of a vertebral body, such as a spinous process. (The system 105 is described herein in the exemplary context of being used with a rod 112 but it should be appreciated that a plate or other interconnecting member may be used in place of the rod 112 .)
[0036] Each body member 110 has a corresponding locking member 122 that couples to the respective body member 110 as described below. In addition, each locking member 122 has a corresponding locking nut 123 that can be threaded onto the locking member 122 and used to apply a downward locking force onto the respective member 110 and the rod 112 to immobilize the member 110 , rod 112 , and locking member 122 relative to one another, as described more fully below. FIG. 3 shows the system 105 with the interconnecting rod 112 detached. FIG. 4 shows the system 105 in an exploded state. It should be appreciated that the use of terms herein such as “upward”, “downward”, “front” and “back” are with reference to the orientation shown in drawings and are not intended to be limiting.
[0037] An exemplary embodiment of the body member 110 is now described with reference to FIG. 5 and FIGS. 6A and 6B . FIG. 5 shows various orthogonal views of the body member 110 while FIGS. 6A and 6B show plan views of the body member 110 . FIG. 6A shows the body member 110 with internal lines and FIG. 6B shows the body member 110 without internal lines. The illustrated embodiment of the system 105 includes a pair of body members 110 , each of which is a mirror image of the other.
[0038] With reference to FIGS. 5 , 6 A, and 6 B, each body member 110 is an elongated body having outer walls that define a cavity that is at least partially enclosed by the outer walls. The body members are sized and shaped to be positioned next to and abut a spinous process of a vertebral body. In particular, each body member 110 includes a first side wall 1102 , a second side wall 1104 opposed to the first side wall, a front wall 1106 and a back wall 1108 opposed to the front wall 1106 . The walls 1102 , 1104 , 1106 , and 1108 define an inner cavity 1109 . The upper and lower boundaries of the inner cavity 1109 may be at least partially open, as depicted, or completely closed by additional walls. The cavity 1109 is adapted to open onto the space outside of member 110 through at least one aperture of the walls 1102 , 1104 , 1106 , and/or 1108 and/or through the upper and lower boundaries of the cavity 109 . That is, in an embodiment, the cavity 1109 is not a completely closed cavity. Thus, the walls 1102 , 1104 , 1106 , and/or 1108 may include one or more holes, apertures, or openings that provide communication between the cavity 109 and a location outside of the body member 110 .
[0039] The cavity 1109 is adapted to receive and contain a bone graft material (which can be bone graft, bone graft substitute, or a combination thereof) so that, when the system is implanted in the spine, the contained bone graft material can contact at least one vertebral bony surface through the aforementioned aperture of the walls or through the upper lower boundaries of the cavity 109 that surround cavity 1109 . The bone graft material may then form a fusion mass with that bony surface.
[0040] With reference to FIG. 5 and FIG. 6B , the side wall 1102 of each body member 110 includes a channel 11022 that is sized and shaped to accept a corresponding locking member 122 . The other side wall 1102 also includes a complementary channel 11042 . The locking member 122 is sized and shaped so that it can be inserted onto a respective body member 110 over the channels 11022 and 11042 as shown in FIG. 2 .
[0041] With reference still to FIGS. 5 , 6 A, and 6 B, the wall 1102 includes one or more cut outs or seats 11024 sized and shaped to accept an instrument that can compress each of the two body members 110 toward and into the side bony aspect of a vertebral spinous process once the system 105 is coupled to a vertebral body. The seat 11024 does not necessarily extend through the full thickness of wall 1102 .
[0042] The wall 1104 of each body member 110 includes one or more protrusions 11044 that are adapted to forcibly penetrate and fixate onto a bony surface of a vertebral bone onto which member 110 is forcibly applied. The protrusions have a shape, such as a pointed shape, that is configured to facilitate penetration into and fixation with the bony surface. One or more full thickness bore holes 11046 may extend through the wall 1104 of each body member 110 so that bone graft material contained in cavity 1109 can pass through the hole(s) 11046 and contact at least a portion of the vertebral bony surface that is in contact with the wall 1104 and thereby form a fusion mass with the vertebral bone.
[0043] As mentioned, the upper and lower boundaries of the cavity 1109 may be at least partially open (as shown in FIG. 5 ). The open upper and lower boundaries provide access to the cavity 109 to facilitate the placement of the bone graft material into cavity 1109 . The open upper and lower boundaries may also serve as means through which bone graft material contained in cavity 1109 may come into contact with the adjacent vertebral bone. Further, in an embodiment, either the upper and/or lower boundaries of the cavity 1109 may contain a closed portion that encloses the upper or lower boundary. For example, the body member 110 may include a lower wall 11092 ( FIG. 6B ) that entirely or at least partially encloses the lower boundary of the cavity 1109 so as to limit contact between the graft material contained in cavity 1109 and structures that are preferably protected from bone graft contact. Such structures may include the dural surface of the spinal nerve column or spinal nerve. The lower wall 11092 may serve other functions, as discussed more fully bellow.
[0044] An exemplary embodiment of a locking member 122 is now described with reference to FIGS. 7 and 8 . Each locking member has a pair of opposed, upwardly extending side walls 1222 that form a space therebetween. The space between the side walls is sized and shaped to complement the shape of the channels 11022 and 11042 on the body member 110 . In this manner, the locking member 122 can be slid or otherwise coupled onto a corresponding body member 110 in the region of the channels 11022 and 11042 . The region of the locking member 122 below the side walls 1222 includes a protrusion 1226 that is contoured or shaped to form a seat that is sized and shaped to receive the rod 112 , as described more fully below. The seat has a rounded surface that may complement the shape of the rod 112 so that the rod 112 can be firmly seated onto the seat. In addition, the lower region of the side walls 1222 form ledges that overhang the seat.
[0045] The ledges and protrusion 1226 collectively form a space/seat in which the interconnecting rod can be captured and/or immobilized relative to the locking member 1222 . The protrusion 1226 may include one more features adapted to accept a spherical portion of the interconnecting rod. For example, an indentation 12262 may be positioned on the protrusion for receiving a spherical portion of the interconnecting rod. The indentation may be sized and shaped to receive any of a variety of shaped portions of the rod not limited to a spherical portion.
[0046] With reference to FIG. 7 , the interior surface of the side walls 1222 may have threads 1224 that threadingly mate with a corresponding locking nut 123 . This permits the locking nut 123 to be threaded downward into the space between the side walls 1222 .
[0047] The assembled system 105 is now further described with reference to FIG. 2 . The two body members 122 are positioned in a spaced apart relationship and coupled to one another via the rod 112 . That is, the rod 112 is seated onto the seats formed by the protrusions 1226 on the lower portion of the locking members 122 . Each of the locking members 122 is positioned on a respective body member 110 such as over the channels 11042 and 11022 ( FIG. 5 ). Thus, the locking members 122 are attached to the body members while the rod 112 is seated on the locking members 122 such that a space is defined between the body members 110 to collectively form the system 105 .
[0048] The body members 110 , locking members 122 , and rod 112 can all be locked and immobilized relative to one another using the locking nuts 123 . In particular, each locking nut is advanced downward into a locking member 122 such that the locking nut provides a downward force onto the body member 110 , at least a portion of which is positioned between the locking nut 123 and rod 112 . With downward advancement of nut 123 , a lower or an inferior surface of the locking nut 123 is moved toward, and forced against, the upper edge(s) of the respective body member 110 . The upper edge(s) may include each of the first side wall 1102 and/or the second side wall 1104 .
[0049] The locking member 122 is thus forced upward relative to member 110 and the interconnecting rod 112 is forcibly constrained between ledge 1226 of the locking member 122 and the surface of the lower wall 11092 ( FIG. 6A , 6 B) of the cavity 1109 . In this way, each of the body members 110 is immobilized relative to the interconnecting rod.
[0050] While rod 112 is depicted as having a spherical portion 1122 in FIGS. 2-3 , a rod having a spherical end (as shown in FIGS. 9A-9B ) may be alternatively used. Further, a straight or curvilinear rod without a spherical protrusion, a plate, or an interconnecting member of any applicable geometric configuration may be alternatively used to interconnect the body members 110 . As can be seen in FIGS. 2 and 9 A- 9 B, the spherical portion of rod 112 interacts with the indentation 12262 in the seat of locking member 122 and also with the lower surface of the wall 11092 of the member 110 . This interaction allows the interconnecting rod 112 to be oriented and fixed in any one of a variety of positions (including non-orthogonal positions) relative to the body member 110 to which it is attached.
[0051] FIG. 10 shows a method of implanting and using the system 105 . In use, the system is positioned posterior to the spinous processes, SP1 and SP2, of the vertebral bones to be immobilized. (Note that in FIG. 10 , the system 105 is positioned above the posterior aspect of the vertebral bones. Thus, the system 105 is actually shown in a position that is anatomically posterior to the vertebral spinous processes, SP1 and SP2.) At this point in the implantation of the system 105 , each of the locking nuts 123 is sufficiently loose so that each body member 110 can move relative to the interconnecting member 112 . The system 105 is then moved so that each body member 110 rests adjacent to a side of each of the spinous processes SP1 and SP2 of the two vertebral bones to be immobilized. That is, the body members will be positioned on either side of at least one spinous process such that a spinous process is positioned between a pair of body members 110 . Each body member 110 is then forced towards (that is, medial) the spinous processes positioned between the body members so that the protrusions 11044 of each second side wall 1104 of each body member 110 is forced into the side of the spinous process that is adjacent to it. In other words, the body members 110 are forced toward one another and also toward the spinous processes positioned between the body members 110 such that the protrusions penetrate the sides of the spinous processes.
[0052] The body members 110 are forced towards one another by the action of at least one driver instrument (in an embodiment, the driver instrument may be shaped like pliers) that is preferably adapted to interact with and compress each body member 110 toward one another. The driver instrument may interact with at, at least, one of indentations/cut outs 11024 of side wall 1102 of each body member 110 . While at least one driver instrument maintains compression across the opposing body members 110 (and maintain a force that pushes the body members 110 toward one another), each of the locking nuts 123 is advanced downward toward the body members, as described above. The locking nuts 123 are advanced until all members (body member 110 , locking member 122 , and rod 112 ) of the system 105 are immobilized relative to one another. The driver instrument(s) is removed and each cavity 1109 (of the body members 110 ) is packed with bone graft material. Note that the bone graft material is then be placed in contact with the lateral wall of the spinous process, or forced out the lower surface of cavity 1109 and placed into contact with the posterior aspect of the vertebral lamina (VL), or both. (In the implanted state, the vertebral lamina are situated anatomically anterior to the implant.) The implanted system is shown in FIG. 11 .
[0053] There is now described an additional embodiment wherein a bone screw assembly may be anchored into the pedicle portion of the vertebral bone and used as an additional point of device fixation. FIG. 12A shows an embodiment of an assembled bone screw assembly. FIG. 12B shows the bone screw assembly in an exploded state. The illustrated screw assembly is for example and those of ordinary skill in the art will appreciate that a large number of bone screws that are presently known, and/or yet to be known, may be alternative used in this application.
[0054] With reference to FIGS. 12A and 12B , the exemplary embodiment of the bone screw assembly includes a bone screw having a head and a shank. The head of the bone screw can be seated in a receiver assembly of the bone screw assembly. The receiver assembly includes an outer housing and an inner housing that collectively form a seat for the head of the bone screw. The bone screw assembly further includes a locking nut assembly that includes an upper member that is positioned above the head of the bone screw, a washer member and a locking nut. The upper member has a pair of outwardly extending arms that fit between upwardly extending prongs of the inner and outer housings of the housing assembly.
[0055] In use, with reference to FIG. 13A and FIG. 13B , at lease one bone screw assembly is placed into a pedicle portion of the vertebral bone. A screw assembly may be placed into the pedicle portion of each of the two pedicles of the lower (i.e., inferior) vertebral bone of the pair of vertebrae to be immobilized. In use, each bone screw may be positioned into the pedicle portion of the vertebral bones using any trajectory that permits proper screw placement. In a preferred embodiment, at least one bone screw is placed into the pedicle portion of the lower vertebral bone through a bone entry point that rests immediately inferior to the inferior articulating process of the upper (i.e., superior) vertebral bone of the pair of vertebrae to be immobilized. In this way, the inferior articulating process of the upper vertebral bone abuts the superior surface of the bone screw and prevents further extension of the upper vertebra relative to the lower vertebra. (Note that a facet joint is anatomically comprised of the articulation between the inferior articulating process (IAP) of an upper (superior) vertebral bone and the superior articulating process (SAP) of a lower (inferior) bone. These definitions of anatomical structures are known to those of ordinary skill in the art. They are described in more detail in Atlas of Human Anatomy , by Frank Netter, third edition, Icon Learning Systems, Teterboro, N.J. The text is hereby incorporated by reference in its entirety.)
[0056] An elongated interconnecting rod is used to interconnect the screw assemblies. A system 105 is placed with body members 110 on each side of the spinous process (as described above) and coupled onto the rod as described above. (Alternatively, the interconnecting rod can be implanted with system 105 assembled and then lowered onto the screw assemblies.) After the placement of all instrumentation, the locking nuts 123 and the locking nut assembly 52 (shown in FIG. 12 ) of the bone screws assemblies are then locked and all members of the system 105 and bone screw assembly are immobilized. FIGS. 13 and 14 shown an assembled construct. This provides a significant increase in the immobilization power of the system 105 .
[0057] In another embodiment, multi-level fixation can be performed with serial implantation of multiple systems 105 . The stepped configuration of each system 105 permits the placement of more than one system 105 on a single spinous process. FIG. 15 shows the fixation of three adjacent vertebral bones using two systems 105 . While the systems 105 are shown attached to bone screws as in the embodiment of FIGS. 13 and 14 , the systems 105 may be alternatively used without a bone screw anchor, as in the embodiment of FIG. 11 .
[0058] FIG. 16 shows use of the system 105 wherein one vertebral bone does not have a spinous process that will permit device fixation. This situation can occur when, for example, the system 105 is used to immobilize the L5 and S1 vertebral bones. In that application, the S1 spinous process is often too small to accommodate the fixation of a portion of body member 110 . In an additional embodiment, the situation can also arise when one of the vertebral bones had undergone a prior laminectomy. In either situation, the system 105 placed such that the body members 110 are affixed to the spinous process of a first vertebra and the pedicle portion of a second vertebra, wherein the attachment to the pedicles is preferably performed through the use of pedicle bone screws. That is, the system 105 is attached to pedicle screws via the rod 112 .
[0059] By way of illustration, FIG. 16 shows that the lamina and spinous process of the inferior vertebra bone V1 have been removed. The lamina 207 and spinous process 209 of the upper vertebra V2 remains intact. While the protrusions 11044 of each body member 110 over the inferior vertebra bone V1 are shown as not contacting one another, in actual application the protrusions 11044 from each body member 110 over the removed lamina may abut at least a portion of the wall 1104 of the other member 110 .
[0060] FIGS. 17A and 17B show an additional embodiment of the system 105 that may be used with a bone screw. In this embodiment, the bone screw 214 transverse the pedicle portion of a first vertebral bone, crosses the disc space between the first and second vertebral bones and enters the inferior surface of the second vertebral bone. While the bone screw is shown being detached from the system 105 , it may be alternatively comprised of a bone screw assembly that can fixate onto the interconnecting rod (similar to the embodiments of FIGS. 13 and 14 ).
[0061] As shown in FIGS. 17A and 17B , a bone screw is used to cross the disc space and fixate the two vertebral bones. This fixation compliments the posterior fixation provided by the system 105 and thus provides fixation of the two vertebral bones that is both anterior and posterior to the spinal canal.
[0062] In an alternative embodiment, a fastener or bone screw may be similarly positioned into the pedicle of the inferior vertebra. The fastener then transverses the pedicle, crosses the disc space between the two vertebrae and enters the inferior aspect of the upper vertebra. The fastener may be further adapted to move the top vertebral bone relative to the lower vertebral bone. After re-positioning of the two vertebral bones, a system 105 may be then applied to the posterior aspect of the two vertebrae. These devices and methods of use are particularly useful to re-align, at least partially, vertebral bones that may be mal-aligned.
[0063] FIG. 18 illustrates an embodiment wherein a bone screw or fastener 310 is positioned through the pedicle of the inferior vertebra V1, across the disc space between the two vertebrae and into the inferior aspect of the upper vertebra. FIG. 19A shows an exemplary embodiment of the fastener 310 . The fastener includes a first threaded elongated segment 3102 and a second threaded elongated segment 3104 that are attached to one another in an assembled state. FIG. 19B shows an assembled fastener wherein the two device segments 3102 and 3104 are attached with at least one link member 3106 . The link members 3106 are elongated members that attach at opposite ends to the device segments 3102 and 3104 in a pivoting manner. The fastener 310 is implanted while in the configuration depicted in FIG. 19B . In this configuration, the link members 3106 are pivoted outward such that the segments 3102 and 3104 are moved further away from one another. After placement, the fastener is transitioned into the configuration shown in FIG. 19C wherein the link members 3106 are pivoted inward such that the segments 3102 and 3104 are moved toward away one another. The instrumentation needed to place the fastener into bone is not shown, but may be a simple driver that engages head 3101 . While not shown, the mechanism and/or instrumentation needed to transition the fastener from the configuration of FIG. 19B into the configuration of FIG. 19C may include any of the mechanism/instruments known in the art movement of a member 3104 relative to a member 3102 . For example, it is contemplated that a small internal threaded screw is positioned within proximal member 3102 . The engagable head of the small internal screw rests within head 3101 and the internal screw has a trajectory within the interior of the screw 310 that is eccentrically positioned along the long axis of member 3102 . The trajectory of the small internal screw is schematically shown by A in FIG. 19C . To transition the screw 310 from the embodiment of FIG. 19B to the embodiment of FIG. 19C , the small screw is engaged and threadedly advanced so as to forcibly abut the member 3106 within the interior of screw 310 at or about point X ( FIG. 19C ). With advancement of the small internal screw, member 3106 is forcibly rotated about a fixation pin 31066 .
[0064] FIG. 20 illustrates how, with transition to the configuration of FIG. 19C , the fastener 310 can produce the posterior movement of the upper vertebra V2, as well as an increase in the distance between the vertebra across the disc space. The fastener can also produce an increase in segmental lordosis, wherein the lordotic curvature of the lumbar spine is reformed, with a change to the configuration of FIG. 19C . While the link members 3106 are shown as being substantially equal in length, they may alternatively be non-equal so at produce desired movement of the bones (such as additional lordosis) with configuration change of the fastener. After reducing the bones as shown in FIG. 20 , the system 105 may be attached to the spinous processes of the vertebral bones in order to immobilize the vertebrae in this position. This is shown in FIG. 21 . While bone screw 310 is illustrated as a singular bone screw with the movable feature discussed above, it may alternatively contain a proximal housing assembly that is adapted to accept an interconnecting rod. A example of a screw assembly is shown in FIG. 12 . The illustrated screw assembly is for example and those of ordinary skill in the art will appreciate that a large number of bone screws that are presently known, and/or yet to be known, may be alternative used in this application.
[0065] The disclosed devices or any of their components can be made of any biologically adaptable or compatible materials. Materials considered acceptable for biological implantation are well known and include, but are not limited to, stainless steel, titanium, tantalum, shape memory alloys, combination metallic alloys, various plastics, resins, ceramics, biologically absorbable materials and the like. Any components may be also coated/made with osteo-conductive (such as deminerized bone matrix, hydroxyapatite, and the like) and/or osteo-inductive (such as Transforming Growth Factor “TGF-B,” Platelet-Derived Growth Factor “PDGF,” Bone-Morphogenic Protein “BMP,” and the like) bio-active materials that promote bone formation. Further, any surface may be made with a porous ingrowth surface (such as titanium wire mesh, plasma-sprayed titanium, tantalum, porous CoCr, and the like), provided with a bioactive coating, made using tantalum, and/or helical rosette carbon nanotubes (or other carbon nanotube-based coating) in order to promote bone in-growth or establish a mineralized connection between the bone and the implant, and reduce the likelihood of implant loosening. Lastly, the system or any of its components can also be entirely or partially made of a shape memory material or other deformable material.
[0066] While this specification contains many specifics, these should not be construed as limitations on the scope of an invention that is claimed or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.
[0067] Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
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A spinal implant device immobilizes an attached vertebrae through a minimally invasive surgical approach while providing a compartment within the implant for the placement of bone graft or bone graft substitute. The bone graft material fuses the spinous processes and/or lamina portion of bone of the vertebral bone to which the device is attached.
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FIELD OF INVENTION
[0001] The present invention is directed to a system and method for manufacturing filtration media.
BACKGROUND
[0002] In the manufacturing process for filtration membrane materials, it is sometimes necessary to flush a continuous web of membrane material wetted with a first solvent in a bath containing a second solvent. This may be done to remove residues of other solvents left over from previous steps in the manufacturing operation. It may also be done to impregnate the web with other chemicals to impart different mechanical or physical properties, such as hydrophilicity, hydrophobicity, surface charge, ion exchange capabilities, strength and appearance, to the membrane material.
[0003] Two methods have been predominantly used to flush continuous webs of membrane material. In the conventional “mass transfer” technique, the first solvent-wetted web is simply soaked in a bath containing the second solvent. The period of time required for soaking is dependent upon the diffusion properties of the solvents and the effective area of the membrane-bath interface. The process is relatively slow since no driving force other than diffusion is used to move the first solvent out of the membrane material and replace the first solvent with the second solvent. For thin membrane materials, the diffusion-induced driving force for the mass transfer process can be approximated according to Fick's First Law as:
J net =−DΔC/Δx (1)
[0004] where: J net is the net diffusional flux, ΔC is the difference in concentration between the two regions separated by a distance of Δx, and D is the “diffusion coefficient”, a proportionality constant with dimensions of cm 2 /sec.
[0005] A second process commonly used for web flushing involves the use of a “water” bearing, which is a hollow tube with openings in its exterior through which water or some other flushing chemical may be pumped. In a flushing process of this type, the membrane material web is floatably supported by water flowing from the interior of the water bearing tube through the exterior openings. Because there is no contact between the membrane material and the water bearing, this technique is often used for applications in which it is important that the introduction of surface defects in the membrane web be minimized. Flushing of the first solvent from the web is improved through the use of water bearings, since support of the membrane web on a layer of water produces a differential pressure gradient across the membrane web. The pressure differential can be approximated as:
P=T/R (2)
[0006] where:
[0007] P=the trans-membrane differential pressure (psi)
[0008] T=the tension on the web (pounds/linear inch)
[0009] R=the radius of the pipe (inches)
[0010] If it is assumed that the portion of the web floatably supported by a water bearing is supported along roughly one-half of the circumference of a cylindrical roller bearing, the amount of time for which any portion of the web is subjected to water flow at this differential pressure can be calculated as:
t flush =ΠR/v web (3)
[0011] where:
[0012] t flush =the time of contact between supporting water and a portion of the web
[0013] v web =the speed at which the web is moving (inches/second)
[0014] Therefore, the volume of water flushed through the web can be calculated as
Volume flushed (per unit area of membrane)=Δ V water /Δt*t flush *P (4)
[0015] where:
[0016] ΔV water /Δt=the flow rate of water through the membrane web (in 3 /in 2 *psi*sec)
[0017] As shown by the above equations, for a system involving water bearings, the volume of water flushed through the web will depend on the tension at which the web is being held, since the pressure differential across the web is directly proportional to the web tension. In many flushing applications, subjecting membrane webs to high tension may cause damage to the membrane web or even contact with the surface of the water bearings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 depicts an portion of a web membrane flushing system according to an embodiment of the present invention; and
[0019] [0019]FIG. 2 depicts a vacuum roller that may be used in an embodiment of the invention.
DETAILED DESCRIPTION
[0020] Embodiments of the present invention relate to a system for flushing a first solvent out of a continuous web of membrane material using a vacuum roller(s). Such a system has improved flushing capabilities over currently used systems because the vacuum pressure applied to the web by the vacuum roller increases the pressure differential across the membrane web, thereby increasing the driving force for removal of the first solvent and replacement with the second solvent.
[0021] [0021]FIG. 1 illustrates a membrane web flushing system according to an embodiment of the present invention. The unflushed membrane web 1 may be a continuous web of membrane material. The unflushed membrane web 1 may be soaked with a first chemical, such as a solvent. The unflusbed membrane web 1 may be fed around a first positioning roller 2 a to the vacuum roller 3 . The arrows in FIG. 1 indicate the direction of feed of the membrane web 1 and the direction of rotation of the vacuum roller 3 , the first positioning roller 2 a and a second positioning roller 2 b. The unflushed membrane web 1 may be held in contact with the vacuum roller 3 by vacuum pressure. Where the unflushed membrane web 1 contains very small pores, fluid retained in the membrane pores due to capillary forces may minimize or prevent air flow through the unflushed membrane web 1 . This may allow vacuum pressure to build up so as to hold the unflushed membrane web 1 in contact with the vacuum roller 3 as the vacuum roller 3 turns. A shield 7 may be mounted inside the vacuum roller.
[0022] The vacuum roller may be partially submerged in a flushing tank 4 containing a flushing chemical 5 , which may also be a solvent, e.g., water. As the vacuum roller 3 rotates, the unflushed membrane web 1 is drawn into the flushing solvent. The vacuum roller 3 may be driven to facilitate movement of the membrane web 1 over the roller assembly. When the unflushed membrane web 1 is submerged in the flushing chemical 5 , the flushing chemical 5 may be drawn into the pores of the membrane web 1 by the differential pressure created by the vacuum. One of the advantages of the present invention may be that the amount of flushing chemical 5 in the flushing tank 4 necessary to remove the first chemical from the membrane web 1 may be minimized. At the same time, the first chemical may be drawn into the vacuum roller 3 . The first chemical drawn into the vacuum roller 3 may subsequently be drained away. The resulting flushed membrane web 6 may be separated from the vacuum roller 3 and routed around the second positioning roller 2 b. The drained first chemical may be collected and recycled.
[0023] As shown in further detail in FIG. 2, in some embodiments, the vacuum roller 3 may include a cylindrical member 103 constructed of a porous material such as polypropylene or perforated stainless steel. The cylindrical member may rotate about an axle 105 , which may be supported by one or more axle bearings 108 and fixed supports 109 a. The outer surface of the cylindrical member 103 may be machined to a smoothness necessary to prevent the introduction of surface defects to the membrane web via contact with the outer surface of the cylindrical member 103 . The cylindrical member 103 may have multiple openings 101 extending from its interior vacuum chamber 102 to the outer surface of the cylindrical member 103 . The size of the openings 101 may affect the amount of vacuum pressure that can be produced by the vacuum roller. The openings 101 may be located uniformly throughout the cylindrical member 103 and some of these openings 101 may be blocked by a shield 107 so that only the openings 101 that are not blocked by the shield 107 transmit vacuum pressure from the interior vacuum chamber 102 to the outer surface of the cylindrical element 103 . The amount of vacuum pressure that can be produced by the vacuum roller may also be affected by the separation between the shield 107 and the cylindrical element 103 . In order to achieve greater vacuum pressures, a seal may be placed around the shield 107 to reduce the amount of separation between the shield 107 and the cylindrical member 103 .
[0024] Alternatively, only a portion of the cylindrical element 103 may have the openings 101 . The openings 101 need not be circular. In some embodiments, the openings in the cylindrical member 103 may take the shape of lateral channels. The size and pattern of the openings 101 may be selected to ensure that substantially all portions of the unflushed membrane web 1 are subjected to vacuum pressure. Alternatively, the size and pattern of openings 101 may be selected so that vacuum pressure is only applied to selected portions of the membrane web 1
[0025] The amount of vacuum pressure applied to the membrane web may be determined by the density of the unflushed membrane web 1 , the feed rate of the membrane web 1 , the size of openings 101 in the cylindrical element 103 of the vacuum roller 3 , the strength of the vacuum source (such as a vacuum pump), the fluid properties of the first chemical and flushing chemical 5 , and other factors. The amount of vacuum pressure may be controlled to increase the mass transfer rate of the first chemical being removed from the unflushed membrane web 1 .
[0026] Each of the lateral ends of the vacuum roller may be sealed with an end cap 104 , which may act as a plug to seal the interior vacuum chamber 102 . The suction source of a vacuum pump or other pump may be attached to a vacuum pressure inlet 106 so as to create a trans-web pressure differential across the pores of the membrane web. In one embodiment, the one end of the vacuum pressure inlet 106 may connect to a vacuum pressure channel 110 that terminates at a channel opening 111 . The vacuum pressure channel 110 may have one or more channel openings 111 to transmit vacuum pressure to the interior vacuum chamber 102 . A inlet bearing 112 may separate the end cap 104 from the vacuum pressure inlet 106 . Alternatively, a rotary coupling may be used.
[0027] The effective contact area for mass transfer between the unflushed membrane web 1 and the cylindrical element 103 of the vacuum roller 3 may be determined in part by the location of the first and second positioning rollers 2 a and 2 b, the diameter of the vacuum roller 3 , the size of the shield 107 or percentage of openings 101 transmitting vacuum pressure at any instant, and the depth of submersion of the vacuum roller 3 and unflushed membrane web 1 in the flushing chemical 5 , among other factors. The mass transfer rate is affected by the effective contact area, the vacuum pressure applied to the unflushed membrane web 1 through the openings 101 in the cylindrical element 103 of the vacuum roller 3 , the rate of rotation of the vacuum roller 3 and other factors related to the amount of time that any portion of the unflushed membrane web 1 is immersed in the flushing chemical.
[0028] One or more of these factors may be changed in order to increase or decrease the rate of mass transfer. For example, in embodiments of the system, the cylindrical member 103 and vacuum pressure inlet 106 of the vacuum roller 3 may be supported by mounts 109 a and 109 b. The position of the cylindrical member 103 and the vacuum pressure inlet 106 of the vacuum roller 3 may be raised or lowered relative to the mounts 109 a and 109 b so that more or less of the unflushed membrane web 1 is submerged in the flushing chemical 5 . Alternatively, similar results may be accomplished by changing the configuration of the shield 7 so as to expose a greater or fewer number of openings 101 in the cylindrical member 103 of the vacuum roller 3 , thereby applying vacuum pressure to a portion of the unflushed membrane web 1 for a longer or shorter period of time. In other embodiments of the invention, the rate of mass transfer may be controlled by controlling the effective contact area through other means, such as by routing the membrane web around a series of roller assemblies, some or all of which are partially submerged in the flushing chemical 5 .
[0029] One or more of the first positional roller 2 a, the second positional roller 2 b, and the vacuum roller 3 may be driven and the remaining rollers may be undriven. By controlling the rotational velocity of the driven roller(s), the feed rate and tension of the membrane web may be controlled. In embodiments of the invention, both the first and second positional rollers 2 a and 2 b may be driven and their speeds may be independently controlled. In such a system, if the tension on the flushed membrane web exceeds desired amounts, the speed of the second positional roller 2 b may be reduced in relation to the speed of the first positional roller 2 a. The flushing performance of the vacuum roller 3 flushing system of the present invention is largely independent of membrane web tension, allowing the system to be used with delicate membranes that can only be placed under low tension.
[0030] In embodiments of the invention in which the first chemical is drained away after it has been drawn into the vacuum roller 3 , the vacuum pressure inlet 106 may be positioned near the bottom of the cylindrical element 103 of the vacuum roller 3 and in some case, may be submerged below the level of the flushing chemical 5 . The vacuum pressure inlet 106 material is preferably chosen to be chemically compatible with the flushing chemical 5 and/or first chemical.
[0031] While the embodiments particularly described above have generally focused on the use of a vacuum roller 3 , in other embodiments of the invention, vacuum pressure may be applied to the membrane web using a vacuum belt or similar device. In an embodiment using a vacuum belt, the unflushed membrane web 1 may be held against the vacuum belt by vacuum pressure applied through openings in the vacuum belt. The unflushed membrane web 1 may travel in the same direction as the portion of the vacuum belt against which the unflushed membrane web 1 is being held. The vacuum belt may be partially submerged in the flushing chemical 5 . Such an embodiment may also be used with membrane web that is not continuous, e.g. in the form of pre-cut sheets.
[0032] While the description above refers to particular embodiments of the present invention, it should be readily apparent to people of ordinary skill in the art that a number of modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true spirit and scope of the invention. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description. All changes that come within the meaning of and range of equivalency of the claims are intended to be embraced therein.
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The present invention is directed to a system and method for removing a first chemical from a web of filtration membrane material using a vacuum roller or other vacuum pressure application device. Embodiments of the method involve applying vacuum pressure to a surface of the membrane web, immersing said membrane web in a flushing chemical and removing the membrane web from the flushing chemical. Embodiments of the system may include one or more vacuum rollers, positioning rollers and a flushing chemical in which a portion of the membrane web may be immersed.
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TECHNICAL FIELD
[0001] The present invention relates to textile materials and more particularly to textile materials with textured surface patterning formed by the selective application of heat absorbing fluid to the greige fabric prior to heat setting. Methods of formation are also provided.
BACKGROUND
[0002] Fabrics in general are well known. By way of example only, prior techniques for forming fabrics include weaving, stitch bonding, warp knitting, tricot knitting, raschel knitting and the like. In the past textured patterning across fabrics has been carried out by various techniques including shaving, impinging by hot air so as to selectively melt surface yarns in a desired pattern, chemical degradation in a desired pattern using acid etching or the like, and impingement by high pressure water streams so as to dislodge and/or reorient surface fibers in a desired pattern. While such techniques have been useful, they have nonetheless been relatively complex and difficult to carry out due to the need to use specialized equipment to carry out the patterning procedures. Moreover, these techniques result in abrasion and/or reorientation of surface yarns thereby changing the construction features across the fabric
SUMMARY
[0003] The present invention provides advantages and alternatives over the prior art by providing a method for forming a patterned textile fabric by applying a pattern of heat absorbing fluid to a greige fabric surface using, for example, printing equipment to form zones of differential heat absorption across the fabric. The differential heat absorption properties across the fabric are then used to selectively heat shrink at least a portion of the yarns in locations outboard of the fluid application. Because the pattern is formed by printing or other application equipment, the resultant pattern may be of substantial complexity. The resulting fabrics may find uses in any number of applications including residential and/or automotive upholstery wherein substantial fabric integrity is required.
[0004] According to one aspect, yarns with different heat shrinkage character may be used in combination with one another across the fabric structure. It is also contemplated that single surface yarn system may be used if desired.
[0005] According to another aspect, differential pile heights across the fabric may substantially correspond to differential dye acceptance characteristics thereby providing synergistic tactile and visual differentiation across the fabrics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The accompanying drawings which are incorporated in and which constitute a part of this specification illustrate several exemplary constructions and procedures in accordance with the present invention and, together with the general description given above and the detailed description set forth below, serve to explain the principles of the invention wherein:
[0007] FIG. 1 illustrates schematically a stitch bonding process for selectively forming a patterned surface yarn system and a cooperating ground yarn system through a fibrous substrate;
[0008] FIG. 2 illustrates schematically the stitching of a ground yarn in an arrangement of substantially flat chain stitches by a multiplicity of reciprocating needles;
[0009] FIG. 3 illustrates schematically the stitching of a surface yarns in a pattern of loops by a first pair of cooperating reciprocating needles;
[0010] FIG. 4 illustrates schematically a treatment process for selectively heat shrinking surface yarns across a fabric;
[0011] FIG. 5 further illustrates schematically an exemplary process whereby a heat sink fluid pattern is applied to the face of the fabric by a rotary screen printer, resulting in a pattern of treated and untreated areas on the fabric surface;
[0012] FIG. 6 illustrates schematically a cross-section taken through the fabric with zones treated with heat absorbing fluid; and
[0013] FIG. 6A illustrates schematically the fabric of FIG. 6 subsequent to heat treatment.
[0014] While a description will hereinafter be provided in connection with certain exemplary embodiments, procedures and practices, it is to be understood and appreciated that in no event is the invention to be limited to the embodiments, procedures and practices as may be illustrated and described herein. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications as may embrace the broad principles of this invention within the true spirit and scope thereof.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Reference will now be made to the drawings, wherein to the extent possible like reference numerals are utilized to designate like elements throughout the various views. A method as utilized to form a fabric of stitch bonded construction is illustrated schematically in FIG. 1 . The illustrated method utilizes a stitch bonding machine 10 as will be known to those of skill in the art. Importantly, it is to be understood and appreciated that while various contemplated practices will hereinafter be described in relation to pile fabrics formed on a stitch bonding machine, the invention is not limited to such stitch bonded pile fabrics. To the contrary, it is contemplated and intended that the techniques of the invention are equally applicable to flat fabrics formed by stitch bonding, weaving, knitting and other techniques as well as to pile fabrics formed by techniques other than stitch bonding including tufting, knitting and the like.
[0016] In the illustrated exemplary practice a substrate material 30 such as a carded and cross-lapped fleece or a needle-punched or spun bonded fleece is conveyed to a stitch-forming position in the direction indicated by the arrow. In a potentially preferred practice, the substrate material 30 is needle-punched fleece formed from about 4 denier polyester staple filaments although other suitable substrate materials may likewise be utilized if desired. The substrate material 30 may include a percentage of low melting point fibers such as low melting point polyester or bicomponent polyester having a core of relatively high melting point material and a sheath of lower melting point polyester to facilitate heat activated point bonding so as to enhance structural integrity.
[0017] As illustrated through simultaneous reference to FIGS. 1 , 2 , and 3 , the stitch forming position is defined by a row of reciprocating needles 34 , 34 ′, and 34 ″ etc. extending in adjacent relation to one another across the width of the substrate material 30 substantially transverse to the direction of movement of the substrate material 30 . As will be appreciated, while only three needles have been illustrated, in actual practice a large number of such needles are arranged in close relation to one another in the cross machine direction between the fingers 47 of a sinker bar.
[0018] According to the illustrated practice, three yarn systems are used to form stitches through the substrate material 30 . In the illustrated practice, a ground yarn 36 ( FIG. 2 ) is carried through a first set of moveable yarn guides 38 carried by a back guide bar (not shown) for cooperative substantially fully threaded engagement with the needles 34 , 34 ′, 34 ″ etc. across the width of the substrate material 30 . For ease of reference, the substrate material is not illustrated in FIG. 2 .
[0019] As will be appreciated by those of skill in the art, in operation the ground yarn 36 is moved into engagement with the needles which, in turn, carry the ground yarn 36 in reciprocating manner through the substrate material 30 without engaging finger elements 47 of the sinker bar so as to form an arrangement of cooperating ground yarn stitches 40 extending in relatively closely spaced parallel rows along the substrate material 30 . By way of example only, and not limitation, the cooperating ground yarn stitches 40 may be held in a full chain stitch configuration although other stitch arrangements including tricot stitches and the like may likewise be utilized if desired. Preferably, the spacing of the stitch lines formed by the ground yarn 36 will be close enough that the ground yarn stitches 40 define a substantially continuous covering across the user contact surface 41 of the substrate material 30 . The ground yarn 36 and the substrate material 30 thus define a substantially stable stitch bonded structure. By way of example only and not limitation, one ground yarn 36 that may be particularly suitable is a 70 denier polyester filament yarn, although other yarns may likewise be utilized if desired.
[0020] According to one exemplary practice, a first collection of loop elements 42 , is formed projecting away from and standing above the ground yarn stitches across the fabric defining a user contact surface 41 . If desired, at least a second collection of loop elements 43 , may also be formed projecting away from and standing above the ground yarn stitches across the fabric. In the event that multiple collections of loop elements are utilized, it is contemplated that the loop elements 42 and 43 may be formed from either the same or different yarn materials. Thus, the yarns forming the pile may be characterized by either the same or different heat shrinkage characteristics. In this regard, it is contemplated that using yarns with different heat shrinkage character across the fabric may be desirable in some instances.
[0021] According to a contemplated practice, the loop elements 42 , 43 may be formed substantially concurrently with the formation of the ground yarn stitches 40 through the substrate material 30 . The loop elements 42 , 43 may be selectively formed in a predefined pattern across the surface 41 of the fabric. In this regard it is to be understood that the first collection of loop elements 42 may be formed in either the same pattern or a different pattern than the second collection of loop elements 43 . According to a preferred practice, the loop elements 42 , 43 are formed so as to cover substantially the entire face of the fabric. However, it is also contemplated that the loop elements may be present only across selected portions of the fabric if desired to provide a combination of two dimensional and three dimensional surface character.
[0022] An exemplary technique for forming the loop elements 42 , 43 is illustrated in FIG. 3 wherein the substrate material 30 and ground yarn 36 have been eliminated for ease of reference. According to this practice, the first collection of loop elements 42 may be formed by a surface yarn 44 fully threaded through moveable yarn guides 46 carried by a middle guide bar (not shown). While only a single surface yarn 44 is illustrated for explanatory purposes, it is to be understood that in actual practice, multiple surface yarns 44 are used across the width of the fabric. During the pile formation process, the surface yarn 44 is carried in alternating fashion back and forth between a first pair of needles 34 , 34 ′ thereby forming a row of loop elements 42 as the pile yarn 44 is carried over the sinker finger 47 between the needles 34 , 34 ′ during stitch formation.
[0023] According to the illustrated practice, the second collection of loop elements 43 may be formed by a surface yarn 48 fully threaded through moveable yarn guides 49 carried by a front guide bar (not shown). While only a single surface yarn 48 is illustrated for explanatory purposes, it is to be understood that in actual practice, multiple surface yarns 48 are used across the width of the fabric. During the pile formation process, the surface yarn 48 is carried in alternating fashion back and forth between a first pair of needles 34 , 34 ′ thereby forming a row of loop elements 43 .
[0024] As will be appreciated, the formation practice illustrated results in the formation of double loops formed from two different surface yarns 44 , 48 . As long as the surface yarns pass between the needles 34 , 34 ′ in a regular stitch forming procedure, a substantially continuous arrangement of loop elements 42 , 43 will be formed along the length of the technical face 41 of the fabric. Of course, a single yarn system may also be utilized wherein one of the surface yarns 44 , 48 is eliminated. According to a potentially preferred practice, the loop elements 42 , 43 are formed so as to form a loop length in the range of about 1 mm to about 5 mm and more preferably a loop length of about 3 mm. Of course, it is likewise contemplated that the fabric formed may have a substantially flat construction. Such a construction may be achieved by simply disengaging the sinker fingers 47 . It is also contemplated that the fabric may be formed to have flat zones and pile-forming zones. The stitch density for the surface yarns in the machine direction of both the loop elements and the ground yarns is preferably about 18 to about 60 stitches per inch and more preferably about 40 stitches per inch.
[0025] According to one contemplated practice wherein yarns with different heat shrinkage characteristics are utilized across the fabric surface, the surface yarn 44 may have a high heat shrinkage capacity with shrinkage activated at temperatures such as the fabric would encounter during normal heat setting operations, while the surface yarn 48 is preferably characterized by a substantially lower heat shrinkage capacity at the same temperature. Accordingly, loop elements 42 shrink to a greater extent than loop elements 43 when exposed to temperatures such as the fabric would encounter during normal heat setting. In this regard it is to be understood that the term “heat shrinkage capacity” is intended to refer to percentage of shrinkage on a length basis that a yarn undergoes when it is raised to a given temperature.
[0026] In the event that different yarn systems having differential heat shrinkage capacity are used, one potentially preferred high shrink yarn is a partially-oriented yarn (POY) of polyester. The polyester POY is preferably a cold drawn yarn with a draw ratio of about 1.35 to about 1.75 (most preferably about 1.57). In this regard, it is to be understood that the term “cold drawn” refers to yarn formed from filaments that are drawn at temperatures below the softening point of the fiber polymer. Most preferably, such drawing is carried out at substantially ambient temperatures. In the absence of elevated temperatures, substantially no thermal setting takes place during the drawing process. The term “partially-oriented yarn” refers to filament yarn that is drawn to a degree such that only partial longitudinal molecular orientation is achieved. One exemplary high shrink capacity surface yarn 44 is 72-filament bright trilobal polyester that has been cold drawn down to 150 denier. An exemplary low shrink capacity surface yarn 48 is a nylon yarn such as a textured yarn formed from Nylon 6 or Nylon 6,6. By way of example only, one such nylon yarn is a 70 denier false twist textured yarn formed from Nylon 6,6. Such yarns undergo a substantially reduced shrinkage at temperatures such as the fabric would encounter during normal heatsetting. As will be described further hereinafter, such yarn combinations facilitate the development of a highly textured face as the greige fabric is passed through a tenter or other heating unit following formation. It is also contemplated that other low shrink capacity yarns such as cellulosic filament yarns of viscose rayon and the like may also be used if desired
[0027] In the event that a single yarn system is to be utilized, the selection of the yarn material utilized will be dependent upon the degree of differential height desired across the fabric. Thus, if substantial differential height is desired, a material with high heat shrinkage capacity such as the polyester POY previously described may be desirable. Likewise, if a subtle differential pile height is desired across the fabric, a yarn material such as the false twist nylon or the like may be desirable.
[0028] As previously noted, it is to be understood that the stitch bonded fabric constructions as outlined above are exemplary only. In this regard it is likewise contemplated that other greige state fabric constructions as will be known to those of skill in the art may likewise be utilized. By way of example only, and not limitation, such alternative fabric constructions may include woven fabrics, warp knitted fabrics, raschel knitted fabrics, chenille fabrics and the like.
[0029] Regardless of whether a single yarn system or a multiple yarn system is utilized, the present system permits the controlled development of surface texturing such that different zones across the finished fabric have different pile heights and dye acceptance characteristics thereby providing substantial tactile and visual differentiation across the fabrics. One exemplary practice for carrying out this method is depicted schematically in FIGS. 4 and 5 . As shown, after formation the greige fabric is advanced towards a printing station 20 . According to an exemplary embodiment, the printing station 20 may include a rotary screen printer incorporating a roller 51 adapted to selectively transfer a volume of heat absorbing fluid to the pile surface 41 of the greige fabric as the fabric is advanced through printing station 20 . The screen printing roller may include a screen pattern 60 disposed about its circumferential face 52 . The screen pattern 60 is selected according to the pattern desired to be imparted on the fabric, and may be easily altered or substituted as desired. Due to the versatility inherent in screen printing, any number of patterns may be imparted to the fabric, ranging from simple geometric forms to such complex patterns as curvilinear forms and text. It is also contemplated that other printing systems may be used to apply the pattern of fluid to the fabric. By way of example only, and not limitation, various alternative fluid printing techniques as may be utilized include flat bed screen printing, fluid jet printing and the like that are suitable for the application of complex patterns. Regardless of the printing technique utilized, the heat absorbing fluid is transferred to the fabric such that a desired pattern of wet or treated zones 62 and dry or untreated zones 64 is produced ( FIG. 6 ).
[0030] In the event that the surface 41 incorporates POY polyester yarns as described above (either alone or in combination with a higher heat shrinkage yarn), the heat absorbing fluid applied to the greige fabric may have a relatively low heat capacity such as a solution of water with an appropriate thickener such as polyacrylate or the like sufficient to increase the solution's viscosity as may be desired to promote the printing process. A viscosity of about 12,000 centipoise may be desirable to promote controlled application and retention of the heat absorbing fluid in patterned relation across the greige fabric. However, higher and lower viscosity levels may be used as desired. Of course, it is contemplated that other aqueous or non-aqueous solutions may likewise be utilized if desired.
[0031] According to one contemplated practice, the heat absorbing fluid may be chilled prior to application to the fabric. By way of example, it has been found that chilling an aqueous polyacrylate solution to about 40 degrees Fahrenheit prior to application to the fabric may be desirable. As will be described more fully hereinafter, the applied fluid is characterized by a heat capacity so as to substantially protect the wetted portions of the fabric from experiencing temperatures that would cause yarn shrinkage. If desired, the applied solution may further include a fugitive tint. The fugitive tint is a temporary coloring that allows an operator to verify that the fabric has been properly wetted according to the desired pattern, thus providing a quality control means to detect and correct any printing errors prior to further processing. Additional or alternative additives may be added to the solution as desired.
[0032] As depicted in FIG. 4 , after the heat absorbing fluid is applied to the surface 41 of the fabric, the fabric is advanced through a heating unit 52 such as a tenter frame for application of heat. Of course, other heating units may likewise be used including laser heaters and the like as may be known to those of skill in the art. As the fabric is advanced through the heating unit 52 , the fabric is exposed to heat, which tends to preferentially shrink the high shrink capacity face yarns forming loop elements 42 such as the POY polyester in the dry portions of the fabric as depicted schematically in FIG. 6A . In the dry portions of the fabric the low shrink capacity yarns forming the loop elements 43 shrink much less than the high shrink capacity yarns in those regions. In the wet zones both the high shrink capacity surface yarns and the low shrink capacity yarns experience relatively little if any shrinkage. By way of example only, according to one potentially preferred practice, the fabric is advanced through about 30 feet of a tenter frame at a rate of about 50-60 yards per minute with a temperature setting of about 200° F. At these settings, it has been discovered that in a stitch bonded fabric made up of a 4 denier needled fleece (substrate 30 ) including 3 mm loops of 70 denier nylon in combination with 3 mm loops of trilobal POY polyester cold drawn to 150 denier, the dry loops of POY polyester will shrink to about 50% of their original length while the wetted loops exhibit substantially no shrinkage.
[0033] Referring again to FIG. 4 , after the fabric is passed through the heating unit 52 , it is preferably wound onto a beam 54 with substantial tension. In this regard it has been found that winding the fabric at high tension levels tends to stabilize the fabric and lock in the heat induced texturing. The fabric may thereafter be subjected to hot water heat setting followed by a dyeing process such as jet dyeing or beam dyeing as may be desired. After dyeing, the fabric is dried, in a drying unit such as a tenter frame or the like. It has been found that the differential shrinkage imparted in the initial heating step is substantially retained. The fabric may thereafter be subjected to a brushing or sanding operation to shear the high and/or low loops across the surface.
[0034] The result of the process as described above is a fabric having a three dimensional pattern defined by areas with differential pile height. Without being limited to a specific theory, it is believed that the selective wetting of the fabric protects the wetted zones while the character of the pile yarns concurrently facilitates shrinkage of the dry zones at relatively low levels of heat input during initial heating. Thus, selective shrinkage can be achieved without overwhelming the protective heat absorbing fluid.
[0035] As previously noted, it has been found that the differential pile heights may substantially correspond to differential dye acceptance characteristics across the fabric. That is, when the fabric is subjected to substantially uniform dyeing, the zones subjected to protective wetting take on a substantially different shade relative to the zones where substantial shrinkage has taken place. Thus, there is a complementary tactile and visual differentiation between the treated and untreated zones across the fabric.
[0036] Aside from the ability to provide simultaneous differentiation of both pile height and dye acceptance character, the process of the instant invention is believed to provide the benefit of substantially retaining the integrity of the fabric construction. Specifically, by using heat induced shrinkage rather than yarn removal or displacement, it is believed that the structural character of the fabric system may be substantially retained. This, in turn, may promote strength in the final product.
[0037] It is to be understood that while the present invention has been illustrated and described in relation to potentially preferred embodiments, constructions, and procedures, that such embodiments, constructions, and procedures are illustrative only and that the invention is in no event to be limited thereto. Rather, it is contemplated that modifications and variations embodying the principles of the invention will no doubt occur to those of ordinary skill in the art. It is therefore contemplated and intended that the present invention shall extend to all such modifications and variations as may incorporate the broad aspects of the invention within the true spirit and scope thereof.
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A method for forming a texture patterned fabric by selectively printing a corresponding pattern of heat absorbing fluid to the greige fabric to form zones of differential heat absorption capacity across the fabric. The differential heat absorption properties across the fabric are then used to selectively heat shrink yarns surrounding locations of fluid application.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 13/288,381 (U.S. Pat. No. 9,009,860) filed on Nov. 3, 2011, entitled “TAMPER RESISTANCE EXTENSION VIA TAMPER SENSING MATERIAL HOUSING INTEGRATION”, the disclosure of which is incorporated herein by reference.
BACKGROUND
Physical device security is essential when a device holding secret data is to be placed in potentially unfriendly hands. To protect the secret data, the device can be configured to sense attempted physical access (e.g., tampering) to the device and can zeroize the data upon the attempted physical access. In order to easily zeroize the data, the data can be stored on a memory device (e.g., a volatile random access memory (RAM)). Sensing the attempted physical access to the device can be accomplished with a tamper sensitive material disposed to detect attempted access to the memory device. When the tamper sensitive material senses an attempted access to the memory device, the memory device can be zeroized thereby rendering the secret data unobtainable.
SUMMARY
Systems and apparatuses disclosed herein provide for a tamper resistant electronic device. The electronic device can include a circuit board, a shell, an anti-tamper material, a memory, one or more sensors, and tamper responsive electronics. The one or more sensors can be configured to sense when the shell moves away from the circuit board. The anti-tamper material can be integrated into the first portion of the shell and disposed to protect the memory, one or more sensors, and the tamper responsive electronics. The tamper responsive electronics on the circuit board can be coupled to the anti-tamper material and the one or more sensors, and can be configured to zeroize data in the memory if tampering is sensed by the anti-tamper material or if one or more of the one or more sensors sense the shell has moved away from the circuit board.
DRAWINGS
Understanding that the drawings depict only exemplary embodiments and are not therefore to be considered limiting in scope, the exemplary embodiments will be described with additional specificity and detail through the use of the accompanying drawings, in which:
FIG. 1A is a perspective view of an example of an electronic device including a plurality of electronic components protected from tampering by a tamper sensitive material.
FIG. 1B is a semi-exploded view of the electronic device of FIG. 1A .
FIG. 2 is a perspective view of an example printed circuit board and the tamper sensitive material from the electronic device of FIG. 1A .
FIG. 3 is a cross-sectional view of the electronic device of FIG. 1A .
FIG. 4 is a block diagram of example components for the electronic device of FIG. 1A .
In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the exemplary embodiments.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments. However, it is to be understood that other embodiments may be utilized and that logical, mechanical, and electrical changes may be made. Furthermore, the method presented in the drawing figures and the specification is not to be construed as limiting the order in which the individual steps may be performed. The following detailed description is, therefore, not to be taken in a limiting sense.
FIGS. 1A and 1B illustrate an example of an electronic device 100 including a plurality of electronic components protected from tampering by a tamper sensitive material. In an example, the tamper sensitive material can be integrated into a larger housing 104 for the electronic device 100 . The electronic device 100 can include a printed circuit board (PCB) 102 that is mounted to the housing 104 (e.g., a shell). The PCB 102 can include a plurality of electronic components mounted thereon and configured to implement the electronic functions of the electronic device 100 . The electronic device 100 can also include a tamper sensitive material 106 (e.g., a security shield, anti-tamper material) disposed to protect one or more of the electronic components on the PCB 102 . In an example, the tamper sensitive material 106 can be integrated into the housing 104 .
FIG. 1A is a view of the electronic device 100 showing the housing 104 in an open position. In an example, the housing 104 comprises multiple parts that are configured to be connected together and can substantially surround the PCB 102 . As shown in FIG. 1A , a first part 104 - 1 of the housing 104 can be configured to cover a first side (e.g., a bottom) of the PCB 102 and a second part 104 - 2 of the housing 104 can be configured to cover a second side (e.g., a top) of the PCB 102 . The first part 104 - 1 can be configured to connect with the second part 104 - 2 to substantially surround the PCB 102 . To secure the PCB 102 in place, the PCB 102 can be mounted to the housing 104 , for example, by mounting the PCB 102 to the first part 104 - 1 . The housing 104 can be composed of any suitable material including plastic, metal, or other materials.
In an example, the tamper sensitive material 106 can be integrated into the housing 104 , for example, into the second part 104 - 2 of the housing 104 . For example, the tamper sensitive material 106 can be integrated into the housing 104 by bonding one or more layers of the tamper sensitive material 106 to a surface of the housing 104 . The tamper sensitive material 106 can be disposed about the housing 104 such that when the housing 104 is secured around the PCB 102 , the tamper sensitive material 106 covers one or more of the electronic components on the PCB 102 . Accordingly, the tamper sensitive material 106 can be disposed to protect one or more electronic components by sensing attempted access of (e.g., tampering with) the one or more electronic components. The one or more electronic components on the PCB 102 that are protected by the tamper sensitive material 106 are referred to herein as the highly protected components 108 . In an example, the highly protected components 108 can include one or more processing devices coupled to one or more memory devices. The one or more memory devices can have data stored therein to which access can be restricted by the physical security of the electronic device 100 . The one or more memory devices can include any type of data including encryption keys, confidential information, software, or other data.
If tampering is sensed by the tamper sensitive material 106 , the data within the one or more memory devices can be zeroized. In one example, the one or more memory devices holding the data can comprise volatile memory, and zeroizing the data can include removing power from the one or more memory devices, thereby removing the data from the memory. Accordingly, the highly protected components 108 can include security electronics that are coupled to the tamper sensitive material 106 and are configured to zeroize the data in the one or more memory devices based on a state of the tamper sensitive material 106 . In an example, the tamper sensitive material 106 is a passive sensor having a plurality of states, wherein each state provides a different reading for the sensor. Accordingly, the security electronics can obtain a reading to determine the state for the tamper sensitive material 106 . The tamper sensitive material 106 can be a capacitive sensor (e.g., a touch sensitive material), an impedance sensor (e.g., formed of Kapton®), an inductive sensor, or other sensing material. In some examples, multiple layers of the tamper sensitive material 106 can be used. In some examples, the tamper sensitive material 106 can include a flexible touch sensitive circuit. Accordingly, some examples of the tamper sensitive material 106 can detect simple touching of the tamper sensitive material 106 . These touch sensitive tamper materials can be used to provide aggressive security for the highly protected components 108 .
In operation, the security electronics can obtain a first reading from the tamper sensitive material 106 prior to an attempted tampering. Then, the security electronics can operate in secure mode by continually obtaining readings from the tamper sensitive material 106 . If the reading from the tamper sensitive material 106 changes in a manner that indicates an attempted tampering, the security electronics can zeroize the data in the one or more memory devices coupled thereto.
FIG. 1B is a semi-exploded view of the electronic device 100 showing the housing in an open position and the tamper sensitive material 106 in an intermediate position to illustrate its position with respect to the circuit board 102 . As mentioned above, the tamper sensitive material 106 can be disposed to protect the highly protected components 108 . In an example, in order to protect the highly protected components 108 the tamper sensitive material 106 can be disposed to cover the highly protected components 108 and generally form an enclosure for the highly protected components 108 using the surface of the PCB 102 . That is, the highly protected components 108 can be mounted on a surface of the PCB 102 . The tamper sensitive material 108 can be disposed opposite the first surface of the PCB 102 , over the highly protected components 108 , and extend such that the tamper sensitive material 108 is adjacent to and detached from the first surface around a perimeter of the highly protected components 108 . Additionally, the PCB 102 can be constructed such that the attempted access to the highly protected components 108 through a second side (the reverse side from the first surface) of the PCB 102 can cause the data in the one or more memory devices to be zeroized and/or can render the highly protected components 108 inoperable. In an example, the PCB 102 has a layer of tamper sensitive material disposed therein which is coupled to the security electronics. Thus, attempted access through the tamper sensitive material in the PCB 102 can also cause the data in the one or more memory devices to be zeroized. In another example, the tamper sensitive material 108 can be disposed around both sides of the PCB 102 such that attempted access from both the first and second side of the PCB 102 can be detected by the tamper sensitive material 108 .
Accordingly, physical access to the highly protected components 108 can be restricted from all directions. For example, attempted access through the second side of the PCB 102 can cause the data to be zeroized and/or can render the highly protected components 108 inoperable. Attempted access through the tamper sensitive material 108 can cause the security electronics to zeroize the data. Accordingly, the data in the one or more memory devices can be protected from unauthorized physical access.
In an example, one or more sensors 110 can be mounted on the PCB 102 and can be configured to sense if the tamper sensitive material 106 is separated from the PCB 102 . In an example, the one or more sensors 110 can include a pressure sensor (e.g., a pressure sensitive switch, microswitch), wherein one or more features 112 physically associated with the tamper sensitive material 106 can be configured to contact and engage the pressure sensor when the tamper sensitive material 106 is closed over (e.g., protecting) the PCB 102 . If the tamper sensitive material 106 is separated from the PCB 102 , the pressure sensor will disengage. The disengaging of the pressure sensor can then be used to indicate that the tamper sensitive material 106 has separated from the PCB 102 and appropriate action can be taken. In another example, the one or more sensors 110 can include a light sensor (e.g., a photocell). When the tamper sensitive material 106 is closed the light sensor detects little light. If the tamper sensitive material 106 is separated from the PCB 102 , however, the light sensor can detect ambient light in the vicinity of the electronic device 100 . Thus, the light sensor can be used to indicate if the tamper sensitive material 106 is separated from the PCB 102 . In an example, both a light sensor and a pressure sensor can be used.
In an example, the one or more sensors 110 can be included in the highly protected components 108 . Accordingly, the one or more sensors 110 can be highly protected from tampering. The one or more sensors 110 can be coupled to the security electronics to enable the security electronics to zeroize the data in the one or more memory devices if the one or more sensors 110 detect that the tamper sensitive material 106 has been separated from the PCB 102 . Thus, the one or more sensors 110 can provide additional protection for the highly protected components 108 .
As shown in FIG. 1A , the tamper sensitive material 106 can be integrated into the housing 104 . In particular, the tamper sensitive material 106 can be integrated into the second part 104 - 2 of the housing 104 . With the tamper sensitive material 106 integrated into the second part 104 - 2 of the housing 104 , the tamper sensitive material 106 will physically move with the second part 104 - 2 of the housing 104 . Accordingly, the one or more features 112 for engaging the pressure sensor of the one or more sensors 110 can be formed in the second part 104 - 2 of the housing 104 . Thus, the data in the one or more memory devices can be zeroized, if the second part 104 - 2 of the housing 104 is separated from the PCB 102 . In an example, the one or more features 112 can extend through the tamper sensitive material 106 in order to contact the one or more sensors 110 . To enable the one or more features 112 to extend through the tamper sensitive material 106 , the tamper sensitive material 106 can include one or more apertures corresponding to the one or more features 112 . The one or more features 112 can extend through the one or more apertures in the tamper sensitive material 106 . In an example, the apertures in the tamper sensitive material 106 can have a size (e.g., a diameter) that is similar to or smaller than a size of a contact area for the one or more sensors 110 . Keeping the size of the apertures of the tamper sensitive material 106 small can help to reduce the likelihood that the interior of the enclosure formed by the tamper sensitive material 106 can be accessed through the apertures.
In addition to providing protection for the highly protected components 108 , the electronic device 100 can also provide tamper protection for electronic components outside the area protected by the tamper sensitive material 106 . This extended tamper protection can be provided by the security electronics detecting if the tamper sensitive material 106 has been separated from the PCB 102 . In particular, since the security electronics can detect when the second part 104 - 2 of the housing 104 and the integrated tamper sensitive material 106 are separated from the PCB 102 , the entire second part 104 - 2 can act as an extended tamper security shield. For example, the second part 104 - 2 can be formed to cover a larger area than the tamper sensitive material 106 such that the second part 104 - 2 extends to cover electronic components on the PCB 102 other than the highly protected components 108 . In an example, this larger area is at least twice as large as the area on the PCB 102 covered by the tamper sensitive material 106 . These other electronic components within the larger area and outside of the area covered by the tamper sensitive material 106 can be protected by having the security electronics take appropriate action if the second part 104 - 2 is separated from the PCB 102 . For example, the security electronics can zeroize the data in the one or more memory devices and/or can zeroize other data within the other components. In an example, the second part 104 - 2 of the housing 104 can extend to cover the entire first surface of the PCB 102 . In this way, tamper protection can be extended to the other components even through these other components are not covered by the tamper sensitive material 106 . Moreover, upon merely opening the housing 104 (e.g., separating the second part 104 - 2 from the PCB 102 ), the data in the one or more memory devices can be zeroized, thus providing increased protection for the highly protected components 108 .
In some examples, one or more of the highly protected components 108 can produce a significant amount of heat. Dissipating the heat from these components can be challenging due to the tamper sensitive material enclosing the components. Accordingly, in some examples, the tamper sensitive material 106 can be configured such that heat can be dissipated from one or more of the highly protected components 108 . For example, the tamper sensitive material 106 can define an aperture 202 above one of the highly protected components 108 . A heat sink 302 can be thermally coupled to the highly protected component 108 through the aperture. The heat sink 302 can extend outward from the aperture above the tamper sensitive material 106 to dissipate heat from the highly protected component 108 .
FIG. 2 is a top view of the PCB 102 and the tamper sensitive material 106 . As shown, the aperture 202 corresponds to a first component 204 of the highly protected components 108 . In an example, the first component 204 is a chip that generates a significant amount of heat (e.g., a processing unit). The aperture 202 can have a size that is approximately the size of an adjacent surface of the chip. In particular, the aperture 202 can be sized large enough such that sufficient contact can be made with the surface of the chip 204 to enable thermal conduction. The aperture 202 , however, can be sized small enough such that access to the interior of the enclosure formed by the tamper sensitive material 106 is difficult or impossible through the aperture 202 . Along with having a size that corresponds with the size of the aperture 202 , the tamper sensitive material 106 can be disposed such that the aperture 202 is close to the surface of the first component 204 . This can further limit the ability to access the interior of the enclosure formed by the tamper sensitive material 106 . In an example, the aperture 202 can be within a range of 0 to 5 millimeters from the surface of the first component 204 . The tamper sensitive material 106 can also include one or more apertures 206 that enable features 112 to extend through and contact sensors 110 . In an example, the one or more apertures 206 are sized corresponding to the one or more features 112 .
FIG. 3 is a cross-sectional view of the electronic device 100 . As shown, the heat sink 302 can extend through the aperture 202 to thermally couple with the first component 204 . Heat flowing into the heat sink 302 from the first component 204 can be dissipated outside of the enclosure via fins of the heat sink 302 . In an example, a thermal interface material 304 can be disposed between the heat sink 302 and the first component 204 to aid in heat transfer. The heat sink 302 can be formed of any suitable material including copper, aluminum, graphene, or other material.
FIG. 4 is a block diagram of example electronic components for the electronic device 100 . As mentioned above, the electronic device 100 can include highly protected components 108 that are protected by the tamper sensitive material 106 and less protected components 402 that are protected by the housing 104 , but not by the tamper sensitive material 106 . In an example, the highly protected components 108 can include a cryptographic processor 404 coupled to one or more memory devices 406 . As mentioned above, the one or more memory devices 406 can have data such as a cryptographic key stored therein. The cryptographic key can be provided to the cryptographic processor 404 and used to encrypt and decrypt data. In an example, the one or more memory devices 406 can include static random access memory (SRAM). The highly protected components 108 can also include a battery 408 coupled to the SRAM. The battery 408 can maintain the data within the SRAM when external power (e.g., line power) is not applied to the electronic device 100 and/or when the electronic device 100 is powered off. Accordingly, the data (e.g., the cryptographic key) within the SRAM can be maintained without needing to be repeatedly externally loaded into the electronic device 100 . Moreover, holding the data in SRAM can enable the data to be effectively zeroized. That is, the data in the SRAM can be zeroized by removing power to the SRAM. Accordingly, upon detection of tampering with the electronic device 100 , power can be removed from the SRAM thus zeroizing the data in the SRAM. Moreover, freezing of the electronic device 100 in an attempt to access the data will also result in power loss to the SRAM, thereby zeroizing the data therein. In some examples, the SRAM can include temperature sensors that automatically zeroize the data upon detecting a temperature reading out of band.
The highly protected components 108 can also include security electronics 410 coupled to control connection of the battery 408 to the one or more memory devices 406 . The security electronics 410 can be configured to cut off power to the one or more memory devices 406 upon detection of tampering with the electronic device 100 . The security electronics 410 can be coupled to the tamper sensitive material 106 in order to detect tampering. In an example, a Wheatstone bridge can be coupled to the tamper sensitive material 106 to sense a change in state in the tamper sensitive material 106 . The security electronics 410 can also be coupled to the one or more sensors 110 in order to zeroize the data in the one or more memory devices 406 if the one or more sensors 110 detect separation of the tamper sensitive material 106 from the PCB 102 . Accordingly, the highly protected components 108 can be configured to implement secret cryptographic functions which are protected from physical access. Thus, the electronic device 100 can be provided to a potentially unfriendly individual and still provide secure cryptographic functions.
In an example, the cryptographic processor 404 can be configured to be coupled to a mass storage device 412 . The mass storage device 412 can hold encrypted data. The electronic device 100 can be configured to send data between the cryptographic processor 404 and the mass storage device 412 . Data from the mass storage device 412 can be decrypted by the cryptographic processor 404 and can be provided to the less protected components 402 . Additionally data to be stored on the mass storage device 412 can be provided by the less protected components 402 , encrypted by the cryptographic processor 404 , and stored on the mass storage device 412 . Accordingly, the data stored on the mass storage device 412 can be protected from unauthorized access.
In an example, the less protected electronics 402 can include electronic components to perform other less secretive functions of the electronic device. For example, the less protected electronics 402 can include a general purpose processor (e.g., a CPU, microprocessor) coupled to a memory device having instructions thereon for implementing the functions of the electronic device.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments shown. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
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Systems and apparatus disclosed herein provide for a tamper resistant electronic device. The electronic device can include a circuit board, a shell, an anti-tamper material, a memory, one or more sensors, and tamper responsive electronics. The one or more sensors can be configured to sense when the shell moves away from the circuit board. The anti-tamper material can be integrated into the first portion of the shell and disposed to protect the memory, one or more sensors, and the tamper responsive electronics. The tamper responsive electronics on the circuit board can be coupled to the anti-tamper material and the one or more sensors, and can be configured to zeroize data in the memory if tampering is sensed by the anti-tamper material or if one or more of the one or more sensors sense the shell has moved away from the circuit board.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the forwarding of “Caller ID data”, defined herein to include any non-verbal information containing a calling party's telephone number, recorded by a call answering device. More particularly, the invention relates to apparatus and systems for recording Call ID data and transmitting the Caller ID data to remote telecommunications devices on demand, to fully or partially automate the dialing process for remotely calling back a message sender.
[0003] 2. Brief Description of the Prior Art
[0004] Caller ID service has become quite common in telephone systems throughout the country. Caller ID service can transmit a data signal together with the ringing signal when a call is placed. The called telephone receives the Caller ID data signal together with the ringing signal.
[0005] If the called telephone has the appropriate display, the name and telephone number (sometimes referred to herein as the “callback” number) of the calling party is displayed on the called telephone display.
[0006] An obvious purpose for Caller ID data is to facilitate call screening. If the called party does not wish to speak with the calling party, the called party can choose not to answer the phone.
[0007] Automatic call answering devices have been available for many decades. Examples include modern multi-media messaging systems, voicemail systems and simple answering machines. Single line devices like simple answering machines couple to the customer's telephone line at the customer's premises. Multi-line devices like voicemail systems may be coupled to subscriber lines at a telephone company central office or at a PBX.
[0008] Although the aforementioned types of answering devices are very different, they operate in similar ways. Typically an automatic answering device answers the customer's telephone after a programmed number of rings, plays a prerecorded announcement and records a message spoken by the calling party. Most modern answering devices also record the date and time of each message recorded.
[0009] A non-obvious benefit of Caller ID service is that the Caller ID service can be used together with an answering device to determine the phone number of a caller who left a message without speaking his phone number or who spoke his phone number in a manner which could not be understood.
[0010] Many Caller ID devices have a memory for storing the names and numbers of at least the last twenty-five callers. Many modern Caller ID devices also have a “callback” option which causes a selected one of the stored numbers to be dialed. The callback option can be used very effectively to return calls to callers who left messages on the answering device without having to write down a number and dial it manually. Unfortunately, this advantageous use of Caller ID data is only available if messages are retrieved at the called number using the answering device physically located at the called number.
[0011] Both answering machines and voicemail systems commonly allow customers to retrieve voice messages from virtually any telephone anywhere. When voice messages are retrieved using a telephone having a number different from the number dialed by the callers who left the voice messages, no Caller ID data is available. This situation also exists with cordless phones which, although having the number called by the callers who left messages, were turned off or out of range at the time the message was left.
[0012] It is very common for people to call answering devices using cell phones and/or pay phones where, for the reasons described above, no Caller ID information is available. This usually requires the person retrieving the messages to write down telephone numbers of callers who spoke their number and then manually redial the numbers to return the calls.
[0013] It would be much more convenient, particularly when using a cell phone to retrieve messages while driving for example, to be able to call back a person who left a message with little manual intervention, for example by simply pushing one button as one would with the call back feature of a Caller ID device, or in some instances with no manual interaction at all.
[0014] Some answering devices do collect Caller ID information and allow a person retrieving messages to call back the person who left the message. However, this feature can be very expensive and can result in so-called “trombone connections”. For example, if a NY cell phone customer is traveling in CA and retrieves a voice mail message from the person he is trying to meet in CA, an answering device call back feature would result in two coast-to-coast long distance calls, i.e. a trombone connection.
SUMMARY OF THE INVENTION
[0015] It is therefore an object of the invention to provide methods and apparatus whereby a call can be fully or partially be automatically placed from a remote location to a person who left a message on an answering device without causing a trombone connection.
[0016] It is also an object of the invention to provide methods and apparatus for transmitting Caller ID data from a called answering device directly to the endpoint of the remote user (i.e., their wireless phone handset, ToL PC client, IP phone, or any digital phone such as an Optiset phone, etc.)
[0017] It is another object of the invention to provide methods and apparatus for forwarding Caller ID data on demand from an answering device to a calling device other than the calling (message retrieval) device, such as a call control system (e.g., a central office to which the calling device is connected), a Caller ID device associated with but not necessarily part of the calling (endpoint message retrieval) device, etc.
[0018] It is yet another object of the invention to provide methods and apparatus which automate the dialing process with little or no intervention when calling back a message sender.
[0019] Still further, it is an object of the invention to be able to retrieve at a remote location, the telephone number of a party leaving a message on an answering device, without having to write the number down or directing attention (as when driving, for example), to remembering the telephone number associated with the message sender.
[0020] In accord with these objects which will be discussed in detail below, the methods according to the invention include (a) collecting Caller ID data at an answering device and (b) transmitting (or interchangeably forwarding) Caller ID data to a calling device which is accessing the answering device for the purpose of retrieving stored messages or simply for the purpose of retrieving Caller ID data.
[0021] According to one embodiment of the invention, utilizing a telephone device having a redial buffer (or other form of associated Caller ID data storage), Caller ID data is sent to the redial buffer memory (or associated memory) of the telephone device. The redial button on the telephone can then, for example, be used to quickly call back the person who left the message just retrieved. Only one connection is used to call back and the trombone type connection is avoided.
[0022] According to another embodiment of the invention, utilizing a telephone device with a built-in or associated Caller ID device, Caller ID data is transmitted to the Caller ID device when the telephone is used to retrieve messages from an answering device or used to simply retrieve Caller ID data from the answering device. The Caller ID device in the telephone can then be used to quickly call back the persons who previously called the answering device regardless of whether they left messages on the answering device. Only one connection is used to call back and the trombone type connection is avoided.
[0023] According to another embodiment of the invention, utilizing a telephone lacking a Caller ID device or a redial buffer memory, Caller ID data is transmitted from the answering device to a call control system (such as the central office of the calling phone, a PBX, ToL Gatekeeper, wireless carrier switch, etc.). Assuming for the sake of illustration only a central office type call control system, the central office (according to one aspect of the invention) provides the calling telecommunications device with the option of calling the number identified by caller ID data. This embodiment of the invention also avoids trombone connections.
[0024] The apparatus of the invention includes memory for storing Caller ID information and an interface for transmitting the Caller ID information when messages are retrieved from an answering device. In the case of the first two embodiments, the apparatus utilizes memory of the phone being used to retrieve messages and/or Caller ID data. In the case of the third embodiment, the apparatus includes central office equipment for receiving Caller ID data and dialing phone numbers based on the data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is a high level block diagram of a first embodiment of the invention.
[0026] [0026]FIG. 2 is a high level block diagram of a second embodiment of the invention.
[0027] [0027]FIG. 3 is a high level flow chart illustrating one of the methods of the invention.
[0028] [0028]FIG. 4 is a high level flow chart illustrating another of the methods of the invention.
DETAILED DESCRIPTION
[0029] Turning now to FIG. 1, an apparatus 10 (according to one illustrative embodiment of the invention) includes a voice message storage and retrieval unit 12 , a Caller ID storage and retrieval unit 14 , and an interface 16 for accessing the storage and retrieval units. The instant illustrative embodiment of the invention is intended to be coupled to a telephone company central office 2 and accessed with a telephone 4 having either an associated Caller ID device 6 having a call back function, a redial buffer accessed by a redial button 7 , or some other memory for storing Caller ID data retrieved from (or forwarded by) apparatus 10 .
[0030] The apparatus 10 may be located within a central office 2 as part of a voice mail system maintained by the telephone company or it may be located remotely from a central office, such as at customer maintained premises.
[0031] The telephone 4 illustrated in FIG. 1 is a wireless phone with a built-in Caller ID device 6 having a call back function and a redial buffer accessed by a redial button 7 . Again however, the apparatus 10 can be used with any telecommunications device (not necessarily a telephone per se, for example a computer, etc.), having either an associated Caller ID device with a call back function, an accessible redial buffer, or other associated memory for storing Caller ID data.
[0032] The operation of the embodiment shown in FIG. 1 is described in more detail below with reference to FIG. 3.
[0033] Turning now to FIG. 2, a second embodiment of the invention includes the same type of apparatus 10 as the first embodiment but is intended to be accessed with a telephone 5 , such as a pay phone, having no Caller ID device or other “intelligence” for retrieving, storing and/or utilizing Caller ID data that could be forwarded by apparatus 10 .
[0034] According to this embodiment, a Caller ID storage and retrieval unit 18 , some form of redial buffer memory, etc., is provided at the central office 3 serving the telephone 5 . It is expected that the telephone company which sells the apparatus 10 or which sells the services of the apparatus 10 will provide Caller ID storage and retrieval units 18 (or some other form of Caller ID data memory and processing capability) at each central office which is coupled to one or more pay telephones from which message and Caller ID retrieval is being supported. For example, it is expected that pay telephones in airports and train stations are likely points from which voice messages may be retrieved and from which connection to callback numbers may wish to be made.
[0035] The operation of the embodiment of FIG. 2 is described in more detail below with reference to FIG. 4.
[0036] Turning now to FIG. 3, and with reference to FIG. 1, the apparatus 10 of the first embodiment of the invention operates in a manner similar to known answering machines and voice mail systems but for the collection and transmission of Caller ID data.
[0037] When a call to the device 10 is received at 20 , the device records the Caller ID data at 22 before answering the call. When the call is answered, if no owner code is entered at 24 , a prerecorded announcement is played at 26 , a message is recorded at 28 , and the call is terminated at 30 .
[0038] If the “owner” of the device enters the proper code at 24 , several options may be presented to the “owner” regarding retrieval of message, returning calls, and retrieval of Caller ID data. FIG. 3 illustrates one possible arrangement.
[0039] As shown in the illustrative example of FIG. 3, after entering the “owner” code, the owner can retrieve messages at 32 . After a message is reviewed, the owner can be given the option at 34 to return the call now or later. Also, the user can be given the option not to return the call at all in which case the exemplary process shown in FIG. 3 continues with message retrieval at 32 . The choice of option can be made by keypress or voice response.
[0040] If the owner opts to return the call now, the system processes the call at 36 using the Caller ID data associated with the message just reviewed. As previously indicated, according to the invention, “processing” a call (as referred to in FIGS. 3 and 4), means stored Caller ID data may be forwarded to an endpoint telecommunications device or call control servicing device (like a central office), for call completion; rather than making a trombone connection via the answering device. However, it should be noted that the invention does contemplate the possibility of allowing a trombone connection to be made via the answering device. For example, all of the preferred options contemplated by the invention may not available to the user (eg., no memory for storing numbers, etc.); a user at a pay phone using the invention may not have enough change to place another call, etc.
[0041] At the end of the call, the system may (optionally) return the owner to the message retrieval menu at 32 if it is determined at 38 that more messages need to be retrieved, otherwise, it may simply hang up at 30 .
[0042] If the owner chooses at 34 to return the call later, the Caller ID data is transmitted at 40 to the owner. Depending on the type of equipment the owner is using, he may only be able to store one callback number. If the owner's equipment includes a memory large enough to store many numbers, he may continue to review messages and store numbers for later callback.
[0043] [0043]FIG. 3 is simplified and it will be appreciated that the step of playing messages at 32 will typically be embedded within menu choices such as fast forward, skip to next message, replay message, delete message, save message, etc. It should also be appreciated that the step 40 of transmitting Caller ID data may be transmitted as a batch of numbers or one at a time as suggested by FIG. 3. In either case, the Caller ID data is transmitted to the owner telephone equipment so that it can be utilized to quickly call back the person who left a voice message.
[0044] From the foregoing, those skilled in the art will appreciate that the described illustrative embodiments of the invention may be easily installed either at customer premises or in a central office; and may easily be added to existing voice mail systems.
[0045] The transmission of Caller ID data from the answering device to the telephone retrieving messages will differ slightly from the manner in which Caller ID data is presently transmitted from a Caller to a called telephone. Caller ID data is now transmitted with a ring signal. In the present invention, no ring signal will be sent to the phone retrieving messages. Nevertheless, the signaling to the telephone preferably utilizes standard protocol so that it is compatible with existing Caller ID equipment. For example, it is presently known to transmit Caller ID data with a Call Waiting signal.
[0046] It will be appreciated, however, that a non-standard signaling could be used and would require that the owner's equipment to be modified to use the signaling adopted by the invention. Possible protocols for transmitting Caller ID data include: any digital signal, any ISDN signal, H.450 signal, a third party call control signal such as TSAPI or CSTA, audio tones in the voice band, an SS7 signal or GSM signals on a wireless network.
[0047] Turning now to FIG. 4, and with reference to FIG. 2, the system 10 receives a call at 41 and records the Caller ID data at 42 before answering the call.
[0048] When the call is answered, if it is determined at 44 that messages are not being retrieved, the recorded announcement is played at 46 and the caller's message is recorded at 48 before the call is terminated at 50 . If it is determined at 44 that the code for retrieving messages has been entered, the system 10 transmits Caller ID data at 52 to the central office unit 18 . A first message is played at 54 and then the central office unit 18 offers the caller the opportunity at 56 to call the party who left the message.
[0049] If the option is chosen at 56 , the central office unit 18 processes the call at 58 . The processing of the call at 58 is preferably accomplished with a dialer at the central office to which the “owner” is most closely connected, thereby avoiding a trombone connection. However, it is expected by the invention that if such equipment is not available at the central office closest to the owner's call, or the user prefers, a trombone connection may (as indicated hereinbefore) be used as a “fall back”.
[0050] So long as it may be determined at 60 that there are more messages to be retrieved, messages continue to be played at 54 , and the user is given the option at 56 to call the party who left the message.
[0051] From the foregoing, those skilled in the art will appreciate that FIG. 4 illustrates only one example of how a call control system (such as central office equipment 18 ) can interact with the equipment 10 in order to provided Caller ID call back functionality to a caller using a telephone which is not provided with a Caller ID device, redial memory, etc.
[0052] It will also be appreciated by those skilled in the art that another method of the invention is to batch load all of the messages and Caller ID data from the equipment 10 to the equipment 18 when messages are to be retrieved thereby freeing the connection between central office 2 and central office 3 while messages are played and calls are returned. In that method, the illustrative central office equipment 18 will look more like the equipment 10 .
[0053] There have been described and illustrated herein methods and apparatus for transmitting Caller ID data from a called answering device to a dialing device, for example a caller retrieving messages from the answering device or a central office device. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise.
[0054] For example, while the invention has been described in conjunction with the retrieval of messages from a message storage and retrieval device, the invention can be used without such a message storage and retrieval device. For example, the invention contemplates a Caller ID storage and retrieval device which records Caller ID data from callers calling the device and which transmits the Caller ID data to a dialing device on the demand of the owner.
[0055] It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed.
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Apparatus and systems for recording Call ID data and transmitting the Caller ID data to remote telecommunications devices on demand, to fully or partially automate the dialing process for remotely calling back a message sender.
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FIELD OF THE INVENTION
This invention relates to a tool or device specifically used to remove the wheel drum and hub assemblies of motor vehicles, particularly large trucks, buses, or automobiles, aiding in the maintenance thereof.
More particularly, it relates to a mobile tool or device, sometimes called a dolly, which can be used to carry heavy wheel drum and hub assemblies of motor vehicles to locations remote from the vehicles, for purposes of maintenance.
BACKGROUND OF THE INVENTION
Large motor vehicles, including tractor-trailers, buses, and trucks, all have wheel assemblies that require maintenance on occasion. In particular, the ball bearings contained in the assemblies often have to be removed and replaced because of excessive wear. Sometimes the ball bearings fuse to the hub housings, therefore the entire assembly has to be removed in order to remove the ball bearings, creating additional problems.
The assemblies, particularly the outer housings, are generally made of cast iron or steel, are heavy, and difficult to remove, often requiring heavy lifting by the person removing them. Often, two or more people are required to assist in the removal of the assemblies for transport to remote locations where maintenance can be performed.
RELEVANT ART
Various patents have been issued relating to devices for removing wheel hubs, and for mounting wheels on hub assemblies. U.S. Pat. No. 4,304,036, Blomgren, Jr., issued Dec. 8, 1991, describes a wheel hub removing tool; U.S. Pat. No. 5,581,866, Barkus, issued Dec. 10, 1996, shows a device for lifting an automobile wheel onto an automobile body; U.S. Pat. No. 5,408,732, Anfuso, issued Apr. 25, 1995, describes a wheel hub puller used to remove a hub assembly from the axle, and U.S. Pat. No. 4,908,925 describes a heavy duty automotive wheel hub puller which is particularly suitable for use when the ball bearings have fused to the housing, and the entire assembly needs to be removed as one piece for servicing.
The aforementioned devices are insufficient because they describe tools useful for removing a hub or wheel assembly, but do not provide means for transporting the hub assembly after removal from the vehicle, to the location where it is to be serviced.
OBJECTS OF THE INVENTION
What is needed is a device which can be used for the dual purpose of removing the hub assembly from the axle of the vehicle, and transporting it to the location where maintenance is to be performed without having to remove it from the device.
The present invention provides an easy and convenient means of removing the wheel drum and hub assembly of large trucks, buses, or automobiles in order to facilitate maintenance of the drum and hub assembly including replacement of the inner bearing race and outer bearing race.
It is, consequently, a principal object of the present invention to provide a wheel drum and hub removal means which does not require heavy lifting in removing the assembly.
It is also a principal object of the present invention to provide a means to enable control and easy manipulation of the wheel drum and hub assembly for maintenance work in the shop or field.
It is further an object of the present invention to provide a wheel drum and hub remover to different sized drum and hub assemblies.
It is a further object of the invention not only to provide a means of easy removal and replacement of the drum-hub assemblies from the vehicle but also for the device to act as a "stand" for the same by allowing the device, with the attached hub-assembly, to be rotated 90 degrees in either direction, to a horizontal and stable position, thereby facilitating removal and replacement of the inner and outer bearing races in the hub.
Further objects will become evident hereinafter.
SUMMARY OF INVENTION
The tool or device of the present invention relates generally to wheel drum and hub removers. Specifically, this invention relates to a wheel drum and hub removal tool that is mobile and allows maintenance of the wheel drum and hub assembly without removing the assembly from the device.
The wheel drum and hub remover has a height-adjustment screw which raises or lowers the supports upon which the wheel drum and hub assembly are situated after removal, thus providing variable size assemblies to be removed. The base of the invention is equipped at one end distally with wheels which enable easy mobility of the drum and hub assembly when it is braced on the supports. The other end of the base provides stability and support when the device is at rest. The device of the invention also includes a handle-receiver for control and maneuverability of it.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purposes of illustrating the invention, there are shown in the drawings embodiments which are presently preferred; however, it should be understood that the invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a perspective view of the heavy duty wheel drum and hub puller apparatus of the invention including the base wheel assembly.
FIG. 2 is a perspective view of the moveable top section of the heavy duty wheel drum and hub puller apparatus of the invention detached from the base wheel assembly.
FIG. 3 is an enlarged view of the moveable top section of the heavy duty wheel drum and hub puller apparatus of the invention with portions cut away.
FIG. 4 is a perspective view of an alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description is the best presently contemplated mode of carrying out the present invention. The mode as presented is not intended in any way to limit or restrict the nature of the invention, but is submitted solely for the purpose of illustrating the general principles of the invention.
Referring now to the drawings in detail, the device or apparatus of this invention is shown in its entirety in FIG. 1. The apparatus 10 comprises a base 12 consisting of a horizontally extending upwardly inverted channel 14, U-shaped in cross section, having a first downwardly inverted horizontally extending channel 16, U-shaped in cross section, mounted transversely at one end thereof, and a second downwardly inverted horizontally extending channel 18, U-shaped in cross section, mounted transversely close to the opposite end thereof. The channels 14, 16, and 18 are preferably made of steel, or cast iron, but could be made of any strong structural material, including aluminum. It is not mandatory that they be U-shaped in cross section, but can be any shape permitting strong, rigid, supporting members.
A pair of wheels, 20 and 22, are mounted at opposite ends of the inverted channel 18, and connected by means of an axle running underneath the channel 18, not shown. A hollow tube 24, square shaped in cross section, is positioned vertically on the upwardly inverted channel 14 and affixed thereto, at a point about midway along the length of the channel 14, and is open at the upper end for receiving the movable portion 26 of the apparatus.
The movable portion 26 of the apparatus, shown in detail in FIGS. 2 and 3, comprises a vertically situated hollow tube 28, square in cross section, having dimensions such that the lower end of it it is adapted to slip into the upper end of the tube 24. The tube 28 has a horizontally projecting first support arm 30 extending forwardly from that side closest to the wheels 20, 22. In resting state, the support arm 30 rests on upper lip of the tube 24. Situated at the distal end of the support arm 30, is a transversely mounted horizontally extending flange plate 32, having a plurality of holes 34, cut into it. The holes are positioned so that they conform in general to the lugs projecting from a wheel and axle assembly of a vehicle, not shown. The support arm 30 is situated at about the midpoint on the tube 28. Toward the upper end of the tube 28 is a second support arm 36 extending horizontally from the tube. The second support arm 36 has a vertically extending flange plate 38 mounted on the end thereof having a plurality of holes 40 cut into it. These holes are also adapted to receive the lugs projecting from a wheel and hub assembly of a vehicle.
A tubular handle-receiver 42 is mounted on the side of the vertical tube 28 opposite to the second support arm 36, and extends horizontally therefrom. A handle 44 can be inserted in the handle-receiver 42 to provide leverage.
Affixed to the top of the tube 28, and closing off the upper end thereof is a nut 46 through which is threaded a height adjusting screw 48. The shaft 50 of the screw 48 is longer than the combined lengths of the tubes 28 and 24, and its distal end rests on the toop surface of channel 14 (FIG. 3). Thus, when the screw 48 is rotated within the nut 46, the movable section 26 of the apparatus of the invention raises or lowers, depending on which direction the screw 48 is rotated. This enables the holes 34 and 40 to be positioned to receive the lugs of hub assemblies situated at various levels off the ground.
In operation, the apparatus of the invention is grasped by the handle 44 inserted in the handle-receiver 42 and rolled up to the site where the wheel and hub assembly is to be removed. The position of the moveable member 26 is adjusted with the height adjusting screw 48 so the holes, 34 and 40, correspond with the lugs projecting from the hub assembly (not shown). The apparatus is then positioned so that the lugs project through the holes 34 and 40, and the lugs are secured by the lug nuts placed on the lugs on the backsides of the flange plates 32 and 38. The hub assembly is then pulled off the axle and transported while on the apparatus 10 to the site where maintenance is to be performed. If desired, in order to facilitate removal of the bearings, the device can be rotated on the wheels 90 degrees, to a horizontal and stable position, one end resting on the distal end of the handle-receiver 42, after rotation.
After maintenance is complete, the reverse procedure is undertaken. That is, the apparatus 10 with the assembly in place is rolled up to the vehicle, the assembly placed back on the axle, and the lug nuts removed from the lugs. The apparatus is backed off leaving the hub assembly in place on the vehicle.
An alternative embodiment of the invention is shown in FIG. 4. In the alternative embodiment, the lower support arm 30, has a flange 52 mounted on the end thereof at a right angle to the support arm, and extends downwardly from the end thereof. The flange 52 has holes 54 in it which are also adapted to receive the lugs projecting from a wheel and hub assembly.
While particular embodiments of the invention have been described herein, it will be understood that the invention is not limited thereto, since many modifications may be made, and it is therefore contemplated to cover any such modifications as fall within the true spirit and scope of the invention.
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Disclosed is a wheel drum and hub assembly remover and rotatable work stand which comprises a mobil base, an upper portion that is movably positioned with regard to the base, and means on said upper portion for engaging the lugs of a wheel drum assembly, whereby a wheel drum and hub assembly can be easily removed and taken to a remote location for servicing in shop or field, and with which all servicing can be accomplished without removal of the hub and drum assembly from the inventive device.
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BACKGROUND
1. Technical Field
The present development relates to supplying oil to lubricate and cool components in a hybrid electric vehicle.
2. Background Art
Typical hybrid electric vehicles (HEVs) in widespread use have a limited battery capacity; in such systems the vehicle operates on electric-only operation for limited periods of time. The components requiring lubrication are supplied by a mechanical pump coupled to the internal combustion engine. Thus, in electric-only operation, the mechanical pump does not rotate and supplies no oil to components in the oil circuit. It has been found that the amount of oil in the components is sufficient for such limited periods of electric-only operation. In such HEVs, the amount of electric-only operation is limited, though, by how long the components can survive on the residual lubricant in the system.
To further reduce petroleum consumption in HEVs, manufacturers are developing plug-in hybrid electric vehicles (PHEVs). The battery pack on a PHEV has a greater storage capacity and the PHEV is provided with charging capability to charge the battery pack from an electrical grid so that the PHEV derives its power from both the electrical grid and petroleum sources. The duration of electric-only operation in a PHEV is significantly increased in comparison to HEVs with limited battery capacity. The lubrication and cooling needs of power-generating and power-transmitting components in the PHEV are not satisfied by the mechanical pump driven by the internal combustion engine.
SUMMARY
According to an embodiment of the present disclosure, an electric pump is fluidly coupled to the oil circuit in parallel with the mechanical pump. When the electric pump is operating, a diagnostic can be performed by determining an actual pressure in the circuit and an expected pressure. The fault is determined when the actual and expected pressures differ by more than a predetermined amount. The fault may indicate a leak or plug in the fluid circuit or a failure of a component in the fluid circuit.
According to an alternative embodiment, the diagnostic is performed by estimating an actual flow rate, estimating an expected flow rate, and detecting the fault when the actual flow rate differs from the expected flow rate by more than a predetermined amount.
An advantage is that the electric pump can be used as a diagnostic to detect faults in the fluid circuit without providing additional sensors to perform such a diagnostic.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an exemplary configuration of mechanical components in a hybrid electric vehicle;
FIG. 2 is a schematic representation of an exemplary configuration of a fluid circuit for lubricating and cooling components in a hybrid electric vehicle;
FIG. 3 is a schematic representation of sensors and actuators coupled to a control unit as part of a hybrid electric vehicle;
FIG. 4 shows an example pulse width train to drive an AC motor and the resulting magnetic flux that the pulse width train induces; and
FIGS. 5 and 6 represent flow charts of methods according to embodiments of the present disclosure.
DETAILED DESCRIPTION
As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the Figures may be combined with features illustrated in one or more other Figures to produce alternative embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. Those of ordinary skill in the art may recognize similar applications or implementations whether or not explicitly described or illustrated.
In FIG. 1 , a schematic of one exemplary mechanical arrangement of components in a HEV is shown. The HEV has multiple propulsion sources capable of providing power at the wheels 12 , including: an internal combustion engine 14 , a fraction motor 16 , and a generator motor 18 . Internal combustion engine 14 is coupled to a transaxle 19 via a shaft 20 . Shaft 20 drives a mechanical oil pump 22 via gear 24 and pump gear 26 , gear 24 being coupled to shaft 20 . Mechanical oil pump 22 pumps oil through a fluid circuit. The fluid circuit is discussed further in regards to FIG. 2 . Mechanical oil pump 22 is driven by engine 14 ; thus, when engine 14 is not rotating, mechanical oil pump 22 is not pumping oil. Engine 14 is also coupled to planetary gears 28 of transmission 30 . Transmission 30 includes planetary gears 28 as well as sun gear 32 and ring gear 34 . A generator motor 18 is coupled to sun gear 32 by shaft 38 . Traction motor 16 is coupled by a shaft 40 and gear 42 to ring gear 34 of transmission 30 . Traction motor 16 is coupled to wheels 12 of vehicle via a reduction gear set 44 and 46 and a differential 48 .
The HEV embodiment shown in FIG. 1 represents one non-limiting arrangement. Alternatively, the components of FIG. 1 are arranged differently and/or the system is comprised of different components.
The components enclosed within the dotted line of FIG. 1 are housed within the transaxle 19 , according to one embodiment. Alternatively, the components shown residing within transaxle 19 may be contained in more than one housing.
Referring to FIG. 2 , a schematic of the lubricant flow system within transaxle 19 is shown. Both the mechanical pump 22 and an electric pump 51 pump lubricant through fluid circuit 50 . Pumps 22 and 51 are arranged in parallel.
Mechanical pump 22 has a pressure relief valve 52 to ensure that a maximum system design pressure is not exceeded in fluid circuit 50 . In the branch of fluid circuit 50 having electric pump 51 , there is also a filter 54 and a heat exchanger 56 . In alternative embodiments, filter 54 and heat exchanger 56 are placed in other parts of fluid circuit 50 . Lubricant is provided to generator motor 18 and to transmission 30 before being returned to sump 58 . Parallel to the flow passing through motor 18 and transmission 30 is another branch to heat exchanger 60 and traction motor 16 , which also returns flow to sump 58 . For schematic purposes, sump 58 is shown as a particular container within transaxle 19 . However, sump 58 may comprise the lower portion of transaxle 19 , forming an oil pan of sorts. An oil pickup 62 extending into sump 58 supplies oil to the inlet of pumps 22 and 51 .
In FIG. 2 , lubricant is shown being provided under pressure to generator motor 18 , heat exchanger 60 , traction motor 16 , and transmission 30 . Alternatively and/or additionally, an oil reservoir 64 is provided near the top of transaxle 19 . Reservoir 64 provides drip lubrication to traction motor 16 and generator motor 18 . Within transaxle 19 , rotating components splash lubricant within the casing of transaxle 19 providing yet another way that lubricant is transported within transaxle 19 . The fluid circuit shown in FIG. 2 is one example of many alternative configurations to provide drip lubrication, pressurized lubrication, spray lubrication, and any combination thereof to the various components within transaxle 19 . Furthermore, the components in FIG. 2 may be arranged in a different order in the fluid circuit in an alternative embodiment.
There are four modes of operation:
Mechanical Electric Mode pump 22 pump 51 Operating condition 1 On On Engine 14 on; flow from mechanical pump 22 insufficient; supplement with electric pump 51 2 On Off Engine 14 on; sufficient flow provided by mechanical pump 22 3 Off On Engine 14 off; use electric pump 51 to cool and/or lubricate system components 4 Off Off Engine 14 off; duration of pure electric operation is short; residual oil from prior operation is sufficient to cool and lubricate
In a HEV, whether the internal combustion engine 14 is operating is based on many factors: state of charge of vehicle batteries, driver demand, operating condition, and ambient conditions to name a few. Turning on engine 14 simply for driving mechanical oil pump 22 can constrain HEV operation and negatively impact overall fuel efficiency of the operation, which is one of the disadvantages of the prior art overcome by an embodiment of the present disclosure in which electric pump 51 is provided in parallel with mechanical pump 22 .
The terms oil and lubricant have been used interchangeably to describe the fluid within transaxle 19 . In one embodiment the fluid is a transmission fluid. Alternatively, the fluid is any fluid that can lubricate the gears, motor bearings, and shaft bearings as well as carry energy to the heat exchanger to keep the components housed within transaxle 19 sufficiently cool and lubricated. In particular, traction motor 16 and generator motor 18 have two such demands: lubrication of their bearings and cooling of motor windings. Lubricant is also provided to transmission 30 to lubricate both gears and bearings. At a particular vehicle operating condition, cooling of traction motor 16 might be more demanding than any other component in transaxle 19 . At another operating condition, providing lubricant flow to transmission 30 may be most demanding. At even another operating condition, providing lubrication to traction motor 16 bearings may be most demanding. According to an aspect of the present disclosure, the amount of lubricant provided is dictated by the most demanding component at any given operating condition.
A schematic representation of electrical connections for a HEV relevant to the present discussion is shown in FIG. 3 . Power module 66 provides a driving current to electric pump 51 . The control for the driving current is commanded to power module 66 from an electronic control unit (ECU) 68 . Generator motor 18 and traction motor 16 may be provided current from or provide current to power module 66 depending on the operating mode of the HEV system. Power module 66 is coupled to a battery pack (not shown) as an electrical energy source/sink. Electric pump 51 includes a pump driven by an electric motor. In one embodiment, the electric motor is an AC motor, in which case the speed of the motor, and thus the pump, can be inferred, as will be discussed in more detail below. In another embodiment, the electric motor is a DC motor. In such a situation, the electric pump speed can be measured by a speed sensor 74 with the signal from speed sensor 74 provided to ECU 68 . Speed sensor may be a Hall effect sensor proximate a toothed wheel rotating with electric pump 51 or any other speed sensor known to one skilled in the art.
According to an embodiment of the present disclosure, operating parameters associated with electric pump 51 can be used to infer flow rate and pressure in the fluid circuit. Such inferred values can be determined whether mechanical pump 22 is operated or not. When both electric pump 51 and mechanical pump 22 are operated, the flow rate provided by mechanical pump 22 is estimated. Because mechanical pump 22 is a positive displacement pump, its estimated output flow rate is based on its rotational speed. Mechanical pump 22 is driven by and coupled to engine 14 via a gear set 24 and 26 . Typically, engine 14 is provided with a toothed wheel 70 and a Hall effect sensor 72 . Sensor 72 provides a signal to ECU 68 , from which engine speed is computed and mechanical pump speed can be computed based on engine speed and a gear ratio of gears 24 and 26 .
Electric pump 51 , in one embodiment, is driven by an AC motor. The pump is controlled by applying a pulse width modulated signal, such as 80 shown in FIG. 4 . The frequency, reciprocal of period, and width of the pulse train 80 applied to windings of an AC motor induces a magnetic flux due to a resulting current flow 82 , thereby causing the AC motor to rotate. The rotational speed of the AC motor is based on the timing and pattern of the applied pulses. The pulses applied to the windings are of longer duration and resulting AC current is higher when a load on the AC motor is high. In such a manner, the torque of the motor can be inferred, or estimated, based on the resulting AC current.
A flowchart showing an embodiment of the present disclosure to determine the component having the most demanding lubrication requirement is shown in FIG. 5 . The algorithm starts in 100 and passes control to block 102 to determine whether the key is on. If not, control passes to block 102 until a positive result is encountered. Upon a positive result in 102 , control passes to block 104 in which a temperature of the windings in a first electric motor, Tw 1 , a temperature of the windings in a second electric motor, Tw 2 , and a powertrain component volumetric flow rate, V, are determined. These three quantities are provided by way of example and not intended to be limiting. For example, in another embodiment, a determination of sufficient lubrication can be based on pressure in place of flow rate. In yet another alternative, the flowchart in FIG. 5 can be contracted or expanded to include fewer or more decision blocks, examples include: three desired pressures (as demanded by a generator motor, a traction motor, and a transmission); two desired maximum temperatures (traction motor and generator motor) and one minimum flow rate (through transmission) and one maximum temperature (traction motor).
Motor winding temperature set points, Tsp 1 and Tsp 2 , may be based on total transaxle 19 losses, preferred motor winding operating temperatures or other criteria. The volumetric flow rate set point, Vsp, may be based on transaxle 19 losses, wear tables, or other criteria. In blocks 106 , 108 , and 110 , it is determined whether Tw 1 is greater than a first set point temperature, Tsp 1 , whether Tw 2 is greater than a second temperature set point, Tsp 2 , and whether the volumetric flow rate, V, is less than a volumetric flow rate set point, Vsp, respectively. If any one of these conditions returns a positive result indicating insufficient lubricant flow, control is passed to block 112 in which the frequency of the AC current is increased to increase the pump rotational speed. In another alternative, the pump is driven by a DC motor and pulse width to the motor is increased to increase motor rotational speed. Or, in another alternative, the speed of electric pump 51 is increased in block 112 according to any other known manner, such as having multiple, selectable windings in electric pump 51 , which can be switched in and out to affect pump capacity. If negative results are returned in all of blocks 106 , 108 , and 110 , control passes to block 114 in which it is determined whether temperatures, Tw 1 and Tw 2 , are lower than their respective set point temperatures, Tsp 1 and Tsp 2 , by more than suitable safety factors, Tsf 1 and Tsf 2 , respectively. It is also determined whether the volumetric flow rate exceeds the volumetric flow set point by a suitable safety factor, Vsf. The expressions in block 114 are evaluated using a Boolean “and” operation. Thus, control passes to block 116 only if all the expressions are true; otherwise, control passes to block 104 . A positive result from block 114 passes control to block 116 in which it is determined whether electric pump 51 is on. If it is not, no further decrease is possible and control passes to block 104 . If the electric pump is on, control passes to block 118 in which speed of electric pump 51 is decreased with control returning to block 104 . Depending on the type of electric motor coupled to the pump, the speed is decreased by decreasing the AC frequency, the pulse width, etc.
Continuing to refer to FIG. 5 , when speed of electric pump 51 is increased in 112 , control passes to 120 in which is determined whether the pump speed is greater than or equal to the maximum pump speed. If not, control passes to 104 . If so, control passes to 122 to notify the ECU of the over speed condition. Also in 122 , electric pump speed is set to the maximum speed before returning to block 104 .
In other embodiments, a time rate of change quantity is also compared to a threshold to determine whether additional fluid supply is desired. For example, an electric motor that is converting electrical energy into mechanical energy or vice versa can heat up very quickly. Thus, a desired cooling level can be based on both the temperature of the windings as well as a rate of change of the temperature of the windings. Additional refinements, such as use of a PID controller, are obvious to one skilled in the art.
In FIG. 5 , safety factors, Tsf 1 , Tsf 2 , and Vsf, are employed. In alternative embodiments, the safety factors are set to zero. Also in FIG. 5 , first and second temperature maxima, Tmax 1 and Tmax 2 , are shown. In one embodiment, the same maximum temperature is used to detect overheating in both electric motors with Tmax 1 equal to Tmax 2 .
It is desirable to maintain the temperature in generator motor 18 and traction motor 16 below a temperature at which damage can result or maximum operating temperature. The temperature in the motor can be estimated based on a model of energy generation within the motor as well as the energy rejection to the lubricant based on flow to and heat transfer characteristics of the motor. Alternatively, motor temperature can be estimated based on a signal from a sensor in or near the motor. In yet another alternative, the temperature is estimated from a measure of resistance of the windings:
R = R ref [1+α(( T−T ref)]
where Rref is the resistance at reference temperature, Tref, and α is the change in resistance per degree temperature change, a material property. Solving for T:
T=T ref+(1/α)( R/R ref−1).
As discussed in regards to FIG. 5 , control is based on estimating temperature of the motor windings. Alternatively, control could be based on maintaining the resistance in the windings below a threshold. In yet another alternative, a flow rate can be determined which provides the desired cooling. Control can be based on providing that flow rate.
Referring to FIG. 6 , a diagnostic routine starts in block 150 . In 152 , it is determined whether electric pump 51 is operating. If it is not, pump 51 is turned on in 154 prior to proceeding to 156 in which the speed and torque of electric pump 51 are determined. In 158 the speed of mechanical pump 22 is determined. Blocks 156 and 158 can be performed in any order. Control passes to block 160 , in which the total flow rate is determined. Control passes to block 162 in which actual electric pump output pressure is determine based on torque. Control then passes to block 164 in which expected pressure is determined based on flow rate and fluid temperature. Block 164 can be a lookup table or computation based on, e.g., a polynomial equation. Block 166 provides input information for the computation or table lookup in block 164 , providing at least the fluid viscosity as a function of temperature and the loss characteristics of the fluid circuit. Control passes to decision 168 to determine whether the absolute value of the difference in the actual and expected pressures exceeds a predetermined pressure difference. A positive result in decision 168 indicates that a fault is detected and control passes to block 170 in which the fault is indicated by setting a fault code or a light indicating a fault to the operator of the vehicle. Alternatively, specific high and low limits may be set based upon typical failure modes. Otherwise, control passes to block 172 . Rather than run a diagnostic test continuously, in one embodiment, block 172 inserts a delay. In an alternative embodiment, the diagnostic is executed only when electric pump 51 is operating, i.e., the pump isn't turned on simply for diagnostic purposes.
While the best mode has been described in detail with respect to particular embodiments, those familiar with the art will recognize various alternative designs and embodiments within the scope of the following claims. While various embodiments may have been described as providing advantages or being preferred over other embodiments with respect to one or more desired characteristics, as one skilled in the art is aware, one or more characteristics may be compromised to achieve desired system attributes, which depend on the specific application and implementation. These attributes include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. The embodiments described herein that are characterized as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
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In hybrid electric vehicles having increased battery storage capacity and plug-in capability, electric-only operation of significant duration is available. To supplement lubrication for the electric and mechanical components provided in a fluid circuit by an engine-driven mechanical pump, an electric pump is provided in parallel to the mechanical pump. When the electric pump is operating, a diagnostic can be performed to determine system integrity. According to one embodiment, an actual quantity provide to the circuit is determined; an expected quantity is estimated; and a fault is determined when the actual and expected quantities differ by more than a predetermined amount. The fault may indicate a leak or plug in the fluid circuit or a failure of a component in the fluid circuit.
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TECHNICAL FIELD
[0001] The present invention is directed to an integrally molded hinge assembly that includes a three-point hinge joined to a swivel member and a base member and method of manufacturing the integrally molded hinge assembly.
BACKGROUND OF THE INVENTION
[0002] A known hinge comprises an assembly of parts made of plastic or metal. The components of the hinge assembly are separately manufactured and typically made from plastic or metal and are assembled together after fabrication. There is a need for a hinge assembly which consists of a minimum number of components and which can be produced without manual assembly of individual parts.
SUMMARY OF THE INVENTION
[0003] In accordance with one example embodiment of the present invention, a hinge structure comprises a single molded swivel hinge molded initially as a unitary structure having a first portion and a second portion. The first portion includes first and second hinge pins extending in opposed directions from a base member. The second portion includes hinge pin receiving portions, the first and second hinge pins having an associated hinge pin receiving portion, each hinge pin receiving portion being molded to result in a cylindrical bore after initial operation of the hinge structure. The first and second hinge pins are triangular in shape over its extent within its associated hinge pin receiving portion.
[0004] In accordance with another example embodiment of the present invention, a hinge assembly is integrally molded from a single operation comprising a hinge member having at least one three-point triangular shaped pin integrally molded and fixedly extending from the hinge member. The hinge member is made from a material. The hinge assembly also includes a swivel member having at least one cylindrical housing circumscribing and having an integrally molded connection with the three-point triangular shaped pin such that initial rotation of the swivel member with respect to the base member breaks the integrally molded connection providing a rotatable attachment between the cylindrical housing and the three-point triangular shaped pin. The swivel member is made from the same material as the hinge member during a single molding operation.
[0005] In accordance with yet another example embodiment of the present invention, a method of making an integrally molded hinge assembly comprises the steps of providing a mold having cavities for forming an integrally molded hinge assembly that includes a base member and a swivel member. The method also includes the steps of inserting a first and a second set of side tooling into the mold to a prescribed distance, injecting material into the mold through at least one port, and filling the cavities with the material. The method further includes the steps of forming an integral connection between the base member and the swivel member and withdrawing the side tooling from the mold creating voids between the base member and the swivel member to enable relative movement therebetween.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:
[0007] FIG. 1 is a perspective view of an integrally molded hinge assembly constructed in accordance with one example embodiment of the invention;
[0008] FIG. 2 is a side view of an integrally molded hinge assembly constructed in accordance with one example embodiment of the invention used in a particular example application;
[0009] FIG. 3 is a side view of the integrally molded hinge assembly of FIG. 1 ;
[0010] FIG. 4A is a dynamic side view of the integrally molded hinge assembly of FIG. 1 , moving from a first to a second position;
[0011] FIG. 4B is a magnified dynamic partial side view of the integrally molded hinge assembly of FIG. 4A ;
[0012] FIG. 5 is a plan view of the integrally molded hinge assembly of FIG. 1 ;
[0013] FIG. 6 is an elevated view of the integrally molded hinge assembly of FIG. 1 ; and
[0014] FIG. 7 is a partial perspective view of a molding process of an integrally molded hinge assembly constructed in accordance with one example embodiment of the invention.
DETAILED DESCRIPTION
[0015] Referring to FIG. 1 , an integrally molded hinge assembly 10 , in accordance with a first example embodiment of the invention, is shown. The integrally molded hinge assembly 10 includes a hinge structure 12 that attaches a base element 14 and swivel element 16 . The hinge assembly 10 is made of a material suitable for molding and is molded into an assembled integral unit by an in-mold assembly process. Such suitable material for the integrally molded hinge assembly could include, but is not limited to, thermoplastic polymers, metals, metal alloys, and/or any combination thereof. The molding of the materials including metals and metal alloys could be achieved in a die cast process, while thermal plastics could be used to form the integrally molded hinge assembly through, for example an injection molding process. Some examples of suitable thermoplastic polymers are polythalamide, nylon 6, nylon 66, nylon 46, Polyphenylene sulfide (PPS), Polyoxymethylene (POM), Polypropylene (PP), and Polybutylene terephthalate (PBT).
[0016] The base element 14 and swivel element 16 are attachable to first and second structures 18 and 20 , respectively, using a plurality of fasteners 22 . Alternatively, an adhesive could be used to attach the base 14 and swivel 16 elements to first and second structures 18 , 20 , or a combination of adhesive and fasteners could be used for attachment. The first and second structures, 18 , 20 represent planer surfaces, but could be any shape or object requiring a swivel hinge connection for joining two structures for relative pivotal movement without departing from the spirit and scope of the claimed invention. In one example embodiment, the integrally molded hinge assembly 10 is used for attaching a brake line to a chassis of a motor vehicle, as depicted in FIG. 2 . The base element 14 is secured by fasteners 22 to the underside of a vehicle 21 and a vehicle brake line 23 is supported by a clip 25 attached to the swivel element 16 .
[0017] The hinge structure 12 comprises first 24 and second 26 triangular shaped hinge posts that are integrally molded within respective first and second cylindrical housings 28 , 30 . The triangular shaped hinge posts 24 , 26 are journaled for rotation within the cylinder housings 28 , 30 , providing three points of substantially continuous contact with each respective cylindrical housing. The molding operation provides voids 32 a , 32 b , 32 c between the triangular shaped hinge posts 24 , 26 and the cylindrical housings 28 , 30 , as best seen in FIGS. 3 , 4 A and 4 B.
[0018] The first and second cylindrical housings 28 , 30 are formed within arms 34 and 36 that extend to a desired height from swivel member 16 . It should be appreciated by those skilled in the art that the rotation of the swivel member 16 with respect to the base member 14 , represented by Θ in FIG. 4A is capable of substantially 360 degrees.
[0019] Centrally located about the hinge structure 12 is a hub 38 having opposing first and second faces, 40 a and 40 b from which the first and second triangular shaped hinge posts 24 , 26 fixedly extend. The hub 38 is attached to the base member 14 . The base member 14 is coupled to the swivel member 16 through the hub 38 , the triangular hinge posts 24 , 26 , and the arms 34 , 36 .
[0020] FIG. 4A illustrates the movement of the swivel element 16 about the base element 14 from a first position A to a second position B. Since the integrally molded hinge assembly 10 is molded as a single piece, initial rotation of the swivel element 12 with respect to the base element 14 breaks the molded connection between the triangular hinge posts 24 , 26 and their respective cylinder housings 28 and 30 at break points 42 , as illustrated in FIG. 4B . The initial rotation breaks the triangular hinge post connections just at the tips of the triangles such that subsequent rotation is freely obtained between the swivel and base elements ( 16 , 14 ), allowing ends 44 of the triangular hinge posts 24 , 26 to achieve substantially continuous three-point contact with the inner diameter of their respective cylindrical housings 28 and 30 .
[0021] FIG. 5 illustrates a plan view of the integrally molded hinge assembly 10 . As can be seen in FIG. 5 , the swivel member 16 includes a relief area 46 in the form of a notch that would allow for rotation of the swivel member 16 with respect to the base member 14 without interfering or contacting the hub 38 during rotation. In an alternative example embodiment (not shown), the relief area 46 could extend laterally across the swivel member 16 between first 34 and second 36 arms. FIG. 6 illustrates an elevated end view of the integrally molded hinge assembly 10 of FIG. 5 .
[0022] FIG. 7 is a schematic view of a method of molding the integrally molded hinge assembly 10 in accordance with one example embodiment of the present invention. The hinge structure 12 , base element 14 , and swivel element 16 are formed as one assembled unit during an in-mold assembly process, such as injection molding. The assembled unit of the hinge structure 12 , base element 14 , and swivel element 16 are molded into a single structure, eliminating the need for multiple parts and costly post-molding assembly processes. In addition to the reduced assembly costs, the integrally molded hinge assembly 10 eliminates quality issues, such as disassembly of the connecting hinge pieces, since disassembly is not possible without completely destroying the hinge. This eliminates the risks associated with conventional hinges that may become disassembled during operation, especially if exposed to an environment having a significant or a sustained amount of vibration.
[0023] In accordance with an example embodiment of the present invention, a molding assembly 50 includes an upper mold 52 and a lower mold 54 . The upper 52 and lower 54 molds contain cavities for forming the components that make up the integrally molded hinge assembly 10 , but are not shown for simplicity. Also for simplicity, sprues, gates, runners, and mold supports have been omitted. The molding assembly includes an injection molding station 56 for injecting the hinge assembly material into the mold cavities that define the integrally molded hinge assembly 10 . It should be appreciated by those skilled in the art that the number of injection molding stations and their locations can vary without departing from the spirit and scope of the claimed invention.
[0024] Prior to injecting the material into the mold assembly 50 , tooling comprising side action assemblies 62 and 64 is inserted through respective side apertures 58 and 60 of the mold assembly 50 until engaging internal stops located at positions A in FIG. 7 on the faces 40 a and 40 b of the hub 38 . After the material is injected into the mold assembly 50 and cooled for a prescribed period of time, the side action assemblies 62 , 64 are withdrawn from the mold assembly 50 as depicted in FIG. 7 to positions B. The removal of the side action assemblies 62 , 64 produces the triangular shaped hinge posts 24 , 26 , cylindrical housings 28 , 30 , and the voids 32 a , 32 b , and 32 c therebetween.
[0025] The side tool assemblies 62 , 64 external constructions include a semi-circular geometrical configuration 62 a , 62 b , 62 c , 64 a , 64 b , 64 c , such that their interaction results in the cylindrical housing 28 , 30 that provides a bearing surface for the triangular shaped hinge posts 24 , 26 . While the side tool assemblies internal constructions provide a planer surface 62 a , 62 b , 62 c , 64 a , 64 b , 64 c , such that their interaction results in the three-point triangular hinge posts 24 , 26 leaving a prescribed integral connection with the housings that would allow separation upon initial rotation of the swivel member 16 about the base member 14 . After the initial rotation, enough material remains at the ends 44 of the triangular shaped hinge posts 24 , 26 to provide continuous contact with the cylindrical housings 28 , 30 .
[0026] The side tool assemblies 62 a , 62 b , 62 c , 64 a , 64 b , 64 c may be the same length and connected at the same point, but are illustrated in a staggered configuration for purposes of clarity in the molding process. After the side tool assemblies 62 , 64 are removed, the upper 52 and lower 54 molds are separated, and the integrally molded hinge assembly 10 is ejected from the mold assembly 50 , thereby completing the molding process.
[0027] From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, it should be understood by those skilled in the art that the base element 14 is equally suitable for rotating about the swivel element 16 and that an unlimited number of surfaces could be represented by the first and second structures, 18 and 20 , for attaching objects or closing plastic retainers, containers, covers and the like without departing from the spirit and scope of the claimed invention. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.
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A hinge structure ( 10 ) comprises a single molded swivel hinge ( 12 ) molded initially as a unitary structure having a first portion ( 14 ) and a second portion ( 16 ). The first portion ( 14 ) includes first and second hinge pins ( 24, 26 ) extending in opposed directions from a base member ( 38 ). The second portion ( 16 ) includes hinge pin receiving portions ( 34, 36 ), the first and second hinge pins ( 24, 26 ) having an associated hinge pin receiving portion ( 34, 36 ), each hinge pin receiving portion being molded to result in a cylindrical bore ( 28, 30 ) after initial operation of the hinge structure ( 10 ). The first and second hinge pins ( 24, 26 ) are triangular in shape over its extent within its associated hinge pin receiving portion ( 34, 36 ).
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[0001] The invention described herein relates to compounds for the preparation of medicaments useful for the treatment of psychiatric and neurological disorders, to processes for their preparation and to pharmaceutical compositions containing them as active ingredients. In particular, the invention described herein relates to compounds with a pyrrolobenzothiazepine structure with typical and a typical antipsychotic activity that can be formulated in pharmaceutical compositions intended for the treatment of acute and chronic psychotic states.
BACKGROUND TO THE INVENTION
[0002] The involvement of dopamine and of the dopaminergic neurons in a variety of psychiatric and neurological disorders, has now been extensively documented (E. R. Kandel, J. H. Schwartz, in “ Principles of Neural Science” Neurology”, Elsevier Science Publishing Co. New York, 1985).
[0003] Among the various pathologies concerned, schizophrenia is characterised by a complex symptomatology caused by abnormal neurotransmission of the main dopaminergic pathways of the central nervous system. The states of hallucination and deliria, described as positive symptoms, are due to increased activity of the mesolimbic dopaminergic pathway, while the cognitive deficits and states of social isolation, indicated as negative symptoms, are attributed to reduced dopaminergic neurotransmission in the frontal cortex.
[0004] The condition of hyperactivation of dopaminergic neurotransmission which underlies the acute and chronic psychotic states of schizophrenia, acute psychoses of unknown aetiology, and the forms of psychosis and agitation that form part of the symptomatology of other diseases, is counteracted from a therapeutic point of view by the use of classic antipsychotic agents, otherwise called neuroleptics, the most representative of which are chlorpromazine (phenothiazine class) and haloperidol (butyrophenone class).
[0005] Chlorpromazine was the first product to prove distinctly effective in the treatment of psychoses. This compound, initially used as a sedative, proved capable of improving the condition of psychotic patients, in that it was capable of inducing a particular indifference to environmental stimuli without altering the state of vigilance of the subjects using it. Thanks to the enormous commercial success of chlorpromazine, a search began in the '50s for new neuroleptic agents and this soon led to the identification of other antipsychotic products belonging to many chemical classes.
[0006] The therapeutic efficacy of the neuroleptics is related to their ability to modulate the dopaminergic neurotransmission of the central nervous system, via blockade of the dopamine receptors.
[0007] Their antipsychotic potency is directly proportional to their ability to bind and block dopamine receptors of subtype D 2 in the cerebral areas involved in abnormal functional dopaminergic neurotransmission. Moreover, psychopharmacology studies show that the dopaminergic hyperactivity that affects the mesolimbic pathway also involves the receptor subtypes D 1 and D 3 . Consequently, the antipsychotic potency of a neuroleptic may also depend on its ability to interact with these receptors, which are densely distributed on the neuronal endings in this pathway (J. Schwartz, Giro B., M. P. Martres & P. Sokoloff “ Neuroscience” 4, 99-108; 1992).
[0008] From the clinical point of view, the antipsychotic efficacy of the numerous neuroleptic agents present on the market is qualitatively equivalent in all cases. They differ only in their potency, in the sense that, whereas some of them are effective at doses of only a few mg, others need to be administered at much higher doses.
[0009] The real differences between the various neuroleptic agents depend on their ability to favour the occurrence of unwanted side effects such as arterial hypotension, sedation and, above all, severe motor abnormalities, some of which are among the most frequent manifestations associated with the clinical efficacy of the treatment. Whereas the former are due to the ability of the product to interact with the alpha-1 adrenergic and H 1 histaminergic receptors, respectively, the latter, common to all neuroleptic agents, are due to blockade of the D 2 receptors of the nigrostriatal dopaminergic system.
[0010] Pharmacological and clinical studies have shown that the simultaneous administration of neuroleptics and products with selective antagonist activity on serotoninergic 5-HT 2a receptors can increase the antipsychotic efficacy of the former and attenuate the occurrence of extrapyramidal symptoms as compared to treatment with neuroleptic agents alone (G. F. Busatto and R. W. Kerwin “ Journal of Psychopharmacology” 11(1), 3-12; 1997).
[0011] Further developments in this sense have led to the generation of drugs with a mixed antagonist component, i.e. which are active on different receptors.
[0012] Clozapine (8-chloro-11-(4-methyl-1-piperazinyl)-5H-dibenzo[b,e][1,4]diazepine) is an antipsychotic agent capable of simultaneously antagonising dopamine on D 2 receptors and serotonin on 5-HT 2 receptors. This new action profile, called “atypical”, allows schizophrenia to be treated with a lower incidence of extrapyramidal symptoms ( J. Med. Chem., 39, 1996, pp. 1172-1188).
[0013] Unfortunately, the occurrence of cases of agranulocytosis has limited the therapeutic use of this drug ( Lancet. 1975, 2, 657).
[0014] Octoclothepine (8-chloro-10-(4-methylpiperazino)-10,11-dihydrodibenzo[b,f]thiepine) is a compound partly endowed with “atypical” activity. Its pharmacological activity has been studied in relation to the optical isomers of this compound ( J. Med. Chem., 1991, 34, 2023-2030): a slightly greater effect on schizophrenia by the (S) form is unfortunately associated with a greater incidence of extrapyramidal effects, so that its use has been withdrawn from clinical trials. The (R) isomer presents a more “atypical” profile, with fewer side effects, but also an inferior general potency. Moreover, the two isomers prove to be endowed with the same activity as 5-HT 2 and D 1 antagonists.
[0015] In view of the studies cited above, the need for antipsychotic agents with substantial therapeutic activity and without side effects remains unsatisfied. In particular, the search continues for antipsychotic agents which present greater neuroleptic activity, a lower incidence of extrapyramidal effects and minimal side effects (agranulocytosis; neutropaenia; sedation; weigh gain; costipation; urinary retention; dryness; hypotension).
ABSTRACT OF THE INVENTION
[0016] It has now been found that compounds of the 9-amino-substituted pyrrolo[2,1-b][1,3]benzothiazepine class, particularly formula (I) compounds
[0017] where:
[0018] R=H, Cl, Br, F, I, C 1 -C 4 alkoxy, C 1 -C 4 alkylthio, C 1 -C 4 alkyl, C 5 -C 6 cycloalkyl;
[0019] R 1 =C 1 -C 4 dialkylamine, where the alkyl groups can be the same or different from one another, 4-alkyl-1-piperazinyl, 4-hydroxyalkyl-1-piperazinyl, 1-imidazolyl, 4-alkyl-1-piperidinyl, 4-alkyl-1-homopiperazinyl;
[0020] R 2 =H, C 1 -C 4 alkoxy, C 1 -C 4 alkylthio, C 1 -C 4 alkyl, CHO, CH═NOH;
[0021] R 3 =H, CHO;
[0022] are endowed with antipsychotic activity.
[0023] One object of the invention described herein therefore consists in the formula (I) compounds indicated here above and their pharmaceutically acceptable salts.
[0024] Another object of the invention described herein consists in processes for the preparation of formula (I) compounds.
[0025] A further object of the invention described herein is the use of said compounds as medicaments useful as antipsychotic agents for the treatment of psychiatric and neurological disorders, particularly disorders related to increased activity of the mesolimbic dopaminergic pathway and/or mesocortical dopaminergic hypofunction such as schizophrenia in its positive and negative symptoms.
[0026] Still another object of the present invention is the use of said compounds as medicaments, in particular as antipsychotic agents, for the treatment of psychosis, such as schizophrenia, paranoid states, manic-depressive states, affective disorders, social withdrawal, personality regression, hallucinations or cognitive dysfunctions.
[0027] Yet another object of the invention described herein consists in pharmaceutical compositions containing a formula (I) compound in a mixture with at least one pharmaceutically acceptable vehicle and/or excipient.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the formula (I) compounds, what is meant by the terms C 1 -C 4 are methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, and ter-butyl.
[0029] Among the formula (I) compounds, a first preferred group includes those in which R 1 is 4-alkyl-1-piperazinyl. A second preferred group includes those in which R is H, Cl, Br, F, I.
[0030] In particular, when R=Cl, R 1 =4-metil-piperazin, R 3 =H, R 2 =H the compounds are typical antipsychotics, while for R=H,F; R 2 =H, CHO, CH 3 ; R 3 =H; R 1 =4-methyl-1-piperazinyl, the compounds are a typical antipsychotics.
[0031] Among typical antipsychotics, one particularly preferred compound is 7-chloro-9-(4-methyl-1-piperazinyl)pyrrolo[2,1-b][1,3]benzothiazepine (hereinafter also referred to as ST1508), particularly the maleate (hereinafter also referred to as ST1699).
[0032] Preferred compounds of formula (I) with antipsychotic a typical activity, according to the invention are:
[0033] 9-(4-methyl-1-piperazinyl) pyrrolo[2,1-b][1,3]benzothiazepine (ST1899);
[0034] 7-fluoro-9-(4-methyl-1-piperazinyl)pyrrolo[2,1-b][1,3]benzothiazepine (ST1928)
[0035] 1-Methyl-9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (ST2092).
[0036] The compounds according to the invention described herein are prepared starting from the formula (Ia) compound
[0037] where R and R 2 are as defined above for the formula (I) compound, which is reacted with the desired amine R 1 H as defined for the R 1 group to yield the formula (I) compounds.
[0038] The preparation of the formula (Ia) compound is described in patent application WO 00/06579, filed in the name of the applicant.
[0039] The transformation from compound (Ia) into compound (I) is effected with known techniques, but it has been seen that the reaction is conveniently achieved by treating compound (Ia) with amine R 1 H in the presence of Lewis acids, e.g. triflates, such as trimethylsilyltrifluoromethane sulphonate, or protic acids, such as sulphonic acids, e.g. p-toluene sulphonic acid.
[0040] The reaction is conducted in a solvent inert to the reagents and the reaction products, or, preferably, amine R 1 H can be used in relation to compound (Ia) in an excess such as to constitute the reaction medium. The reaction parameters are not critical and can be determined by a technician with average experience in the field on the basis of his or her own general knowledge of the subject. For example, the molar ratios of compound (Ia) to amine R 1 H may range from 1:1 to an excess of amine in the sense referred to above. The reaction temperature will be selected also in relation to the type of reagents used, their molar ratios, and the optional presence of a solvent, in which case it may even be as high as the boiling temperature of the solvent, providing this does not lead to decomposition of the reagents themselves. The reaction times are selected on the basis of the parameters outlined above and will be such as to complete the reaction. Attempts to optimise the reaction do not constitute an additional experimental burden and are part of the normal techniques used in chemical synthesis.
[0041] The isolation and purification of the formula (I) compound are accomplished with normal known procedures.
[0042] In a first preferred embodiment of the invention, the formula (Ia) compound is reacted with amine R 1 H, using the latter as a reaction medium, when its physicochemical characteristics so permit. The triflate preferred is trimethylsilyltrifluoromethane sulphonate. The reaction temperature is approximately 120° C. and the reaction time approximately 3 hours.
[0043] In a second preferred embodiment of the invention, the formula (Ia) compound is reacted with amine R 1 H, using the latter as the reaction medium, when its physicochemical characteristics so permit. The preferred sulphonic acid is p-toluene sulphonic acid. The reaction temperature is approximately 180° C. and the reaction time approximately 1-2 hours.
[0044] Objects of the invention described herein are pharmaceutical compositions containing as their active ingredient at least one formula (I) compound, alone or in combination with one or more formula (I) compounds, or, said formula (I) compound or compounds in combination with other active ingredients useful in the treatment of the diseases indicated in the invention described herein, for example, other products with selective antagonist activity on the serotoninergic 5-HT 2a receptors, also in separate dosage forms or in forms suitable for combined therapy. The active ingredient according to the invention described herein will be in a mixture with suitable vehicles and/or excipients commonly used in pharmacy, such as, for example, those described in “Remington's Pharmaceutical Sciences Handbook”, latest edition. The compositions according to the invention will contain a therapeutically effective amount of the active ingredient. The doses will be determined by an expert in the field, e.g. clinician or primary care physician, according to the type of disease to be treated and the patient's condition, or concomitantly with the administration of other active ingredients. By way of an example, we may indicate doses ranging from 0.1 to 100 mg/kg.
[0045] Examples of pharmaceutical compositions are those that permit oral, parenteral, intravenous, intramuscular, subcutaneous or transdermal administration. Pharmaceutical compositions suitable for the purpose are tablets, rigid or soft capsules, powders, solutions, suspensions, syrups, and solid forms for extempore liquid preparations. Compositions for parenteral administration are, for example, all the intramuscular, intravenous and subcutaneous injectable forms, and those in the form of solutions, suspensions, and emulsions. We should also mention the forms presenting controlled release of the active ingredient, whether as oral administration forms, tablets coated with suitable layers, microencapsulated powders, complexes with cyclodextrins, depot forms, e.g. subcutaneous ones, as depot injections or implants.
[0046] The following examples further illustrate the invention.
EXAMPLE 1
a) 7-chloro-9-(4-methyl-1-piperazinyl)pyrrolo[2,1-b][1,3]benzothiazepine (10b) (ST1508)
[0047] [0047]
[0048] Procedure A)
[0049] To a mixture of ketone [9b] (4.5 g; 18 mmol) and N-methylpiperazine (15 ml) was added drop-wise trimethylsilyltrifluoromethane sulphonate (5.7 mL; 31.5 mmol) in 5 minutes.
[0050] The reaction temperature was brought up to 120° C. The reaction, monitored via TLC, was completed in 3 hours. The reaction mixture was left to cool at ambient temperature and the resulting solid mass was dissolved in methylene chloride (50 mL) and washed with water (2×30 mL). The organic phase was anhydrified on sodium sulphate and filtered. Evaporation of the solvent at reduced pressure enabled a crude reaction product to be recovered, which, when chromatographed on silica gel (n-hexane/ethyl acetate 50:50) finally yielded 4.7 g of the title compound.
[0051] Yield: 78%
[0052] TLC (AcOEt) Rf=0.25; MP: 127÷128° C.
[0053] [0053] 1 H-NMR (300 MHz, CDCl 3 ) δ 7.6 (d, 1H, J=2.1 Hz); 7.4 (d, 1H, J=8.5 Hz); 7.2 (dd, 1H, J 1 =8.4 Hz, J 2 =2.0 Hz); 6.7 (m, 1H); 6.6 (m, 1H); 6.2 (m, 1H); 6.1 (m, 1H); 2.9 (m, 4H); 2.6 (m, 4H); 2.3 (s, 3H).
[0054] [0054] 13 C-NMR (300 MHz CDCl 3 ) δ 143.8; 140.5; 137.9; 134.8; 133.2; 129.8; 129.6; 127.9; 123.2; 112.7; 111.6; 111.2; 55.2; 50.1; 46.2.
[0055] Elemental analysis: (C 17 H 18 ClN 3 S): compliant.
[0056] Procedure B)
[0057] A mixture of ketone [9b] (0.15 g; 0.6 mmol), N-methylpiperazine (0.18 g; 1.8 mmol) and p-toluene sulphonic acid (0.296 g; 1.56 mmol) was heated to 180° C.
[0058] The reaction, which rapidly took on a dark colouring, was completed in 1.5 hours. After cooling at ambient temperature, the resulting solid mass was dissolved in methylene chloride (10 mL) and washed with water (2×10 mL). The organic phase was anhydrified on sodium sulphate and filtered. Evaporation of the solvent at reduced pressure yielded a crude reaction product which, when chromatographed on silica gel (n-hexane/ethyl acetate 50:50), yielded 0.10 g of the title compound.
[0059] Yield: 50%
EXAMPLES 2-13
[0060] The synthesis of products 2-13 has been carried out following approaches described in schemes 1
R R 1 R 2 R 3 n ST 2 H Me H H 1 1899 3 H Me CHO H 1 2091 4 H Me CHO CHO 1 2147 5 H Me Me H 1 2092 6 H Me CH═NOH H 1 2129 7 H Me CH 2 OH H 1 2096 8 H Me CH 2 O/Pr H 1 2095 9 Cl Et H H 1 2148 10 Cl Me H H 2 2149 11 Br Me H H 1 2093 12 Br Et H H 1 2150 13 F Me H H 1 1928
[0061] R 1 in the above table identifies the 4-alkyl substituent on the piperazine ring.
[0062] 9-(4-Methylpiperazin-1-yl) Pyrolo [2,1-b][1,3]benzothiazepine (1) (ST1899)
[0063] A solution of 9,10-dihydropyrrolo[2,1-b][1,3]benzothiazepin-9-one (0.24 g, 1.11 mmol), N-methylpiperazine (0.55 mL, 0.50 g, 4.99 mmol) and trimethylsilyl triflate (0.55 mL, 0.68 g, 3.05 mmol) was heated at 120° C. under stirring, after a few minutes further 0.55 mL of N-methylpiperazine were added and the reaction was kept for 3 hours at 120° C. After that time water was added and was extracted with dichloromethane. The organic layer was dried over sodium sulphate, filtered and evaporated to give the crude product that was purified by means of a flash chromatography (20% methanol in ethyl acetate) to afford 0.114 g of the pure title compound as a yellowish solid (84% yield).
[0064] [0064] 1 H NMR (CDCl 3 ) δ 7.65 (m, 1H), 7.50 (m, 1H), 7.34-7.22 (m 2H), 6.75 (m, 1H), 6.20 (m, 1H), 6.12 (m, 1H), 2.89 (m, 4H), 2.53 (m, 4H), 2.34 (s, 3H).
[0065] Elemental analysis (C 17 H 19 N 3 S): compliant.
[0066] 9-(4-Methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine-1-carbaldehyde (2) (ST2091)
[0067] A mixture of phosphorus oxychloride (50.70 μL, 0.08 g, 0.54 mmol) and N-methylformanilide (67.15 μL, 0.07 g, 0.54 mmol) was stirred for 30 minutes at room temperature. Then solid (1) (0.12 g, 0.42 mmol) was added and the resulting mixture was stirred overnight at room temperature. Then water was added and the water phase was extracted with dichloromethane (3×2.5 mL). Combined organic layers were dried over sodium sulphate, filtered and evaporated. Purification was accomplished by means of flash chromatography (5% methanol in dichloromethane) and afforded 0.05 g of the pure desired product as a yellowish crystalline solid (37% yield).
[0068] [0068] 1 H NMR (CDCl 3 ) δ 9.45 (s, 1H), 7.65 (m, 1H), 7.46 (m, 1H), 7.32 (m, 2H), 7.04 (s, 1H), 6.93 (d, 1H, J=3.9 Hz), 6.24 (d, 1H, J=4.3 Hz), 3.15-2.95 (m, 4H), 2.57 (m, 4H), 2.35 (s, 3H).
[0069] MS m/z 325 (M + ), 256, 81, 69 (100), 41.
[0070] Elemental analysis (C 18 H 19 N 3 OS): compliant.
[0071] 9-(4-Methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine-1,10-dicarbaldehyde (3) (ST2147)
[0072] A mixture of phosphorus oxychloride (18 μL, 30 mg, 0.198 mmol) and N-methylformanilide (24 μL, 26 mg, 0.198 mmol) was stirred for 30 minutes at room temperature. Then solid (1) (30 mg, 0.100 mmol) was added and the resulting mixture was stirred overnight at room temperature. Then water was added and the water phase was extracted with dichloromethane (3×2.5 mL). Combined organic layers were dried over sodium sulphate, filtered and evaporated. Purification was accomplished by means of flash chromatography (5% methanol in dichloromethane) and afforded 11.3 mg of the pure desired product as a yellowish crystalline solid (35% yield).
[0073] [0073] 1 H NMR (CDCl 3 ) δ 9.68 (s, 1H), 9.42 (s, 1H), 7.59 (m, 2H), 7.42 (m, 2H), 6.87 (m, 1H), 6.31 (m, 1H), 3.70-3.62 (m, 4H), 2.59 (m, 4H), 2.38 (s, 3H).
[0074] MS m/z 353 (M + ), 324, 295, 83, 70 (100), 57, 43.
[0075] Elemental analysis (C 19 H 19 N 3 O 2 S): compliant.
[0076] 1-Methyl-9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (4) (ST2092)
[0077] To a solution of (2) (0.035 g, 0.107 mmol) in absolute ethanol (0.70 mL), hydrazine monohydrate (182 μL, 0.019 g, 3.74 mmol) was added. The resulting mixture was stirred at reflux for 1 hour. After that time the solvent was removed under vacuum; the yellow solid obtained was dissolved in toluene (0.76 mL) and potassium tert-butoxyde (0.036 g, 0.321 mmol) was added. The reaction mixture was refluxing for further 8 hours. Then water was added, the organic phase was separated and the aqueous phase was extracted with dichloromethane; combined organic layers were dried over sodium sulphate, filtered and evaporated. The crude product obtained was chromatographed (20% methanol in ethylacetate). The desired pure product was obtained in a yield of 60%.
[0078] [0078] 1 H NMR (CDCl 3 ) δ 7.62 (m, 1H), 7.48 (m, 1H), 7.26 (m, 2H), 6.32 (s, 1H), 6.03 (m, 1H), 5.90 (m, 1H), 2.89 (m, 4H), 2.53 (m, 4H), 2.34 (s, 3H), 2.20 (s, 3H).
[0079] MS m/z 311 (M + ), 256, 213, 98, 69, 55 (100).
[0080] Elemental analysis (C 18 H 21 N 3 S): compliant.
[0081] 1-Methylenoxime-9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (5) (ST2129)
[0082] To a solution of (2) (0.010 g, 0.031 mmol) in dichloromethane (1.00 mL), hydroxylamine hydrochloride (0.043 g, 0.062 mmol) and pyridine (5 μL, 0.049 g, 0.062 mmol) were added. The reaction mixture was stirred 1 hour at room temperature then dry potassium carbonate (0.008 g, 0.062 mmol) was added and the mixture was stirred for further 72 hours. After that time hydroxylamine hydrochloride (0.043 g, 0.062 mmol) and dry potassium carbonate (0.017 g, 0.124 mmol) were added and the solution was stirred at 25° C. overnight. Then water was added, the organic phase was separated and the aqueous phase was extracted with dichloromethane; combined organic layers were dried over sodium sulphate, filtered and evaporated. The crude product obtained was chromatographed (10% methanol in ethyl ether) to afford 2.5 mg of the desired product. (17% yield).
[0083] [0083] 1 H NMR (CDCl 3 ) δ 7.80 (s, 1H);7.68 (m, 1H), 7.48 (m, 1H), 7.30 (m, 2H), 6.94 (s, 1H), 6.38 (d, 1H, J=3.9 Hz), 6.15 (d, 1H, J=3.8 Hz), 3.02 (m, 4H), 2.62 (m, 4H), 2.40 (s, 3H), 2.20 (s, 3H).
[0084] MS m/z 340 (M + ), 323, 297, 225, 99, 70 (100), 56, 43.
[0085] Elemental analysis (C 18 H 21 N 4 OS): compliant.
[0086] 1-Hydroxymethyl-9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (6) (ST2096)
[0087] To a solution of (2) (17 mg, 0.052 mmol) in absolute ethanol (2.36 mL), sodium borohydride (7.13 mg, 0.188 mmol) was added. The resulting mixture was stirred overnight at room temperature. After that time the solvent was removed, the residue was treated with water and the solution was extracted with dichloromethane; combined organic layers were dried over sodium sulphate, filtered and evaporated. The crude product obtained was chromatographed (10% methanol and 10% triethylamine in ethyl acetate) to afford 9.5 mg of the desired pure product (yield 58.8%).
[0088] [0088] 1 H NMR (CDCl 3 ) δ 7.63 (m, 1H), 7.49 (m, 1H), 7.29 (m, 2H), 6.76 (s, 1H), 6.14 (d, 1H, J=3.7 Hz), 6.05 (d, 1H, J=3.8 Hz), 4.51 (m, 1H); 3.05 (m, 4H); 2.47 (m, 4H), 2.32 (s, 3H).
[0089] MS m/z 327 (M + ), 296, 225, 198, 87, 70 (100), 58.
[0090] Elemental analysis (C 18 H 21 N 3 OS): compliant.
[0091] 1-Isopropoxymethyl-9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (7) (ST2095)
[0092] To a solution of N-[9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine-1-yl]-N-tosylhydrazyne (37 mg, 0.075 mmol) in 2-propanol (4.0 mL), sodium borohydride (13 mg, 0.449 mmol) was added in portions while stirring at 0° C. The resulting mixture was stirred for 24 hours at reflux then for 48 hours at room temperature. After that time the solvent was removed, the residue was treated with water and the solution was extracted with dichloromethane; combined organic layers were dried over sodium sulphate, filtered and evaporated to give the crude product which was chromatographed (0.8% methanol in ethyl acetate) to afford pure (7) as yellowish crystals (51.4% yield).
[0093] [0093] 1 H NMR (CDCl 3 ) δ 7.63 (m, 1H), 7.48 (m, 1H), 7.27 (m, 2H), 6.76 (s, 1H), 6.14 (m, 1H), 6.05 (m, 1H), 4.37 (s, 1H); 3.60 (m, 1H), 2.52 (m, 4H), 2.92 (m, 4H), 2.34 (s, 3H), 1.17 (s, 3H), 1.14 (s, 3H).
[0094] MS m/z 369 (M + ) (100), 326, 310, 296, 97, 70.
[0095] Elemental analysis (C 21 H 27 N 3 OS): compliant.
[0096] 7-Chloro-9-(4-ethylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (8) (ST2148)
[0097] Starting from 7-chloro-9,10-dihydropyrrolo[2,1-b][1,3]benzothiazepin-9-one (0.19 g, 0.76 mmol) and N-ethylpiperazine (0.70 mL, 6.13 mmol), the title compound was obtained following the above described procedure for (1). After purification, 0.19 g of the desired product were obtained as a white solid (yield 74%).
[0098] [0098] 1 H NMR (CDCl 3 ) δ 7.62 (d, 1H, J=1.9 Hz), 7.41 (d, 1H, J=8.0 Hz), 7.22 (d, 1H, J=8.0 Hz), 6.73 (m, 1H), 6.57 (s, 1H), 6.20 (m, 1H), 6.10 (m, 1H), 2.88 (m, 4H), 2.50 (m, 6H), 1.10 (t, 3H, J=7.1 Hz).
[0099] Elemental analysis (C 18 H 20 ClN 3 S): compliant.
[0100] 7-Chloro-9-(4-methylhexahydro-1H-1,4-diazepin-1-yl)pyrrolo[2,1-b]-[1,3]benzothiazepine (9) (ST2149)
[0101] The title compound was obtained following the above described procedure for (1), starting from 7-chloro-9,10-dihydropyrrolo[2,1-b][1,3]benzothiazepin-9-one (0.03 g, 0.12 mmol) and 1-methylhomopiperazine (0.06 mL, 5.41 mmol). After purification the desired product was obtained with a yield of 41%.
[0102] [0102] 1 H NMR (CDCl 3 ) δ 7.53 (d, 1H, J=2.4 Hz), 7.43 (d, 1H, J=8.8 Hz), 7.22 (dd, 1H, J=8.4, 2.4 Hz), 6.75 (m, 1H), 6.55 (s, 1H), 6.19 (m, 1H), 6.11 (m, 1H), 3.20 (m, 4H), 3.15-2.61 (m, 4H), 2.40 (s, 3H), 1.95 (m, 2H).
[0103] MS m/z 345 (M + ) (100), 205, 140, 97.
[0104] Elemental analysis (C 18 H 20 ClN 3 S): compliant.
[0105] 7-Bromo-9-(4-methylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (10) (ST2093)
[0106] A solution of 7-bromo-9,10-dihydropyrro[2,1-b][1,3]benzothiazepin-9-one (0.10 g, 0.34 mmol), N-methylpiperazine (0.169 mL, 1.53 mmol) and trimethylsilyl triflate (0.169 mL, 0.935 mmol) was heated at 120° C. under stirring, after a few minutes further 0.50 mL of N-methylpiperazine were added and the reaction was kept for 3 hours at 120° C. After that time water was added and the water phase was extracted with dichloromethane. The organic layer was dried over sodium sulphate, filtered and evaporated to give the crude product that was purified by means of flash chromatography (20% methanol in ethyl acetate) to afford 0.114 g of the title compound as a yellowish solid (84% yield).
[0107] [0107] 1 H NMR (CDCl 3 ) δ 7.76 (s, 1H),7.37 (m, 2H), 6.73 (m, 1H),6.57 (m, 1H), 6.20 (m, 1H), 6.10 (m, 1H), 2.87 (m, 4H), 2.53 (m, 4H), 2.35 (s, 3H); Elemental analysis (C 17 H 18 BrN 3 S) C, H, N.
[0108] 7-Bromo-9-(4-ethylpiperazin-1-yl)pyrrolo[2,1-b][1,3]benzothiazepine (11) (ST2150)
[0109] The title compound was obtained following the above described procedure for (10), starting from 7-bromo-9,10-dihydropyrrolo[2,1-b][1,3]benzothiazepin-9-one (0.10 g, 0.34 mmol), N-ethylpiperazine (0.169 mL, 1.53 mmol) and trimethylsilyl triflate (0.169 mL, 0.935 mmol); then further 0.50 mL of N-ethylpiperazine were added. After purification 0.125 g of the desired pure product was obtained as a white solid (94% yield).
[0110] [0110] 1 H NMR (CDCl 3 ) δ 7.76 (s, 1H), 7.36 (s, 1H), 7.26 (s, 1H), 6.75 (m, 1H), 6.57 (s, 1H), 6.21 (m, 1H), 6.10 (m, 1H), 2.90 (m, 4H), 2.60-2.46 (m, 6H), 1.12 (t, 3H, J=7.0 Hz); MS m/z 390 (M + +H), 356, 137, 111, 97, 84 (100), 69, 57.
[0111] Elemental analysis (C 18 H 20 BrN 3 S): compliant.
[0112] 7-fluoro-9-(4-methyl-1-piperazinyl)pyrrolo[2,1-b][1,3]benzothiazepine (ST1928)
[0113] The title compound was prepared starting from 7-fluoro-9,10-dihydropyrrolo[2,1-b][1,3]benzothiazepin-9-one and following the procedure A as described in example 1.
[0114] Molecular Pharmacology
[0115] a) Evaluation of Ability to Interact with D 1 , D 2 , D 3 and 5HT 2a Receptors.
[0116] Interaction with D 1 , D 2 , D 3 , and 5HT 2a receptors was studied using various different cerebral areas (striate D 1 and D 2 ; olfactory tubule D 3 ; prefrontal cortex 5HT 2a ) according to the method described in the literature (Campiani et. al. J. Med. Chem . pp.3763-3772,1998).
[0117] Interaction with the D 1 receptor was evaluated using the radioligand [ 3 H]-SCH 23390 (0.4 μM) and the aspecific binding was determined in the presence of (−)-cis-flupentixol (10 μM). For the D 2 receptor 3 H-spiperone (0.2 nM) was used and the aspecific binding was determined in the presence of 100 μM of (−) sulpyride.
[0118] As regards the D 3 receptor, the radioligand chosen was 3 H-7-OH-DPAT which was used at the concentration of 0.2 μM and the aspecific binding was obtained in the presence of dopamine 1 μM. Lastly, interaction with 5HT 2a was evaluated using 3 H-ketanserine (0.7 μM) and the aspecific binding was determined in the presence of methysergide 1 μM.
[0119] b) Evaluation of Ability to Interact with the H 1 Histamine and α 1 -Adrenergic Receptors.
[0120] Interaction with H 1 Receptors
[0121] Interaction with H 1 receptors was studied using rat cortex membranes incubated with [ 3 H]-pyrilamine at a concentration of 1 nM in phosphate buffer 50 mM pH 7.4 for 60 minutes at 30° C., according to the procedure described by Hill (S. J. Hill, P. C. Emson, J. M. Young “ J. Neurochemistry” 31, 997-1004; 1978). Aspecific binding was determined in the presence of 100 μM of pyrilamine.
[0122] Interaction with α 1 Receptors
[0123] The interaction with β 1 -adrenergic receptors was evaluated on rat cortex using the radioligand [ 3 H]-prazosin (0.2 nM), according to the procedure described by Greenglass (P. Greenglass, R. Bremner “ Eur. J. Pharmacol.” 55, 323-326; 1979).
[0124] Aliquots of membrane protein were incubated for 30 minutes at 25° C. with the radioligand and the aspecific binding was determined in the presence of 100 μM of prazosin.
[0125] General Pharmacology
[0126] Evaluation of Catalepsy
[0127] The test was performed on Wistar male rats (N=7 animals); catalepsy was evaluated by means of a metal bar measuring 0.6 cm in diameter positioned at a distance of 10 cm from the work surface. The substance studied, in the form of maleic acid salt (ST1699), was administered subcutaneously 30 minutes prior to the evaluation. The subsequent evaluation times were 60, 90, 120, 180, 240, and 300 minutes after administration. The test consisted in positioning the animal with its forepaws on the bar and measuring the time the animal remained attached to the bar, considering an end-point of 60 seconds (N. A. Moore et al. Journal of Pharmacology and Experimental Therapeutics Vol. 262 pp. 545-551 (1992)).
[0128] Results and Discussion
[0129] Table 1 gives the means and standard deviation of the affinity values expressed as Ki (nM) of the study product ST1508 for the dopaminergic receptors D 1 , D 2 and D 3 ; the serotoninergic receptor 5-HT 2a , the alpha 1 -adrenergic receptor and the H 1 histaminergic receptor.
[0130] In addition, the table presents the affinity values for the above-mentioned types of receptors for the compound haloperidol, as a reference belonging to the neuroleptic drug class, for the purposes of verifying the typical antipsychotic profile of the product studied.
TABLE 1 D 1 D 2 D 3 5-HT 2a α 1 H 1 K i ± ds K i ± ds K i ± ds K i ± ds K i ± ds K i ± ds ST1508 1.9 ± 0.1 0.43 ± 0.04 2.0 ± 0.1 0.34 ± 0.05 4.3 ± 0.1 2.7 ± 0.02 Haloperidol 318 ± 59 4.81 ± 1.0 18.2 ± 1.5 164 ± 23.6 12 ± 2.5 386 ± 0.001
[0131] The product ST1508 shows a substantial ability to interact with the receptor types considered. In particular, it can be seen that the low affinity values for the D 1 , D 2 and D 3 receptors indicate a strong reaction of the product with the dopaminergic system, which is even better than that found for the haloperidol receptor profile.
[0132] This particular receptor profile enables the compounds according is to the invention described herein to be defined as classic antipsychotic agents. In fact, the D 1 , D 2 and D 3 receptor affinity values indicate that the compounds are capable of exerting an effect on the hyperactivity condition of the mesolimbic dopaminergic system responsible for acute and chronic psychotic states.
[0133] Table 2 gives the means and standard deviation of the affinity values expressed as Ki (nM) of the preferred compounds ST1988, ST1928 and ST2092 for the dopaminergic receptors D 1 , D 2 D 3 ; and for serotoninergic receptor 5-HT 2a . Typical (haloperidol) and a typical (Clozapine, Olanzapine) antipsychotics binding affinities are represented.
TABLE 2 5-HT 2a D 1 D 2 D 3 Compound Ki (nM) ± ds Ki (nM) ± ds Ki (nM) ± ds Ki (nM) ± ds Clozapine 10 ± 1 353 ± 35 250 ± 57 319 ± 65 Olanzapine 4 ± 1 85 ± 3.5 69 ± 17 26 ± 7.75 Haloperidol 164 ± 24 318 ± 59 4.8 ± 1 18 ± 1.5 ST1508 0.34 ± 0.05 1.9 ± 0.1 0.43 ± 0.04 2.0 ± 0.1 ST1899 0.6 ± 0.1 19 ± 1.3 17 ± 4.5 8 ± 0.5 ST1928 0.35 ± 0.04 7.7 ± 0.58 8.5 ± 5 2.70 ± 0.10 ST2092 1.1 ± 0.05 154 ± 116 126 ± 15 18 ± 1
[0134] Preferred compounds display high affinity at 5-HT 2 receptor as a typical reference antipsychotics Clozapine and Olanzapine and differently from Haloperidol.
[0135] Moreover, ST1899, ST1928 and ST2092 binding affinity at 5 HT 2 receptor is greater than D 2 dopamine receptor, which resembles the binding characteristics of a typical antipsychotics.
[0136] In vitro, classification of a typical and typical antipsychotic drugs could be done considering 5-HT 2 versus D 2 affinity (pKi values) ratio and Log Y score (Meltzer H Y et al. “ Classification of typical and atypical antipsychotics drugs on the basis of dopamine D 1 , D 2 and serotonin 2 pKi values” J. Pharm. Exp. Ther. 1989, 251, 238-246). Antipsychotic with a 5-HT 2 versus D 2 affinity (pKi values) ratio greater than 1.12 and Log Y score smaller than 6.48 has an a typical profile. In table 3 the affinity ratios and Log Y score of typical (Haloperidol) and a typical antipsychotics (Clozapine and Olanzapine) are compared to those of preferred compounds. ST1899, ST1928, ST2092 display an a typical profile in similar fashion to Clozapine and Olanzapine. Furthermore, ST2092 display an a typical profile better than reference compounds.
[0137] About ST1508, 5-HT 2 versus D 2 affinity ratio and LogY score values confirm a typical profile for this compound. Despite of high capacity interaction at 5HT 2 receptor (similarly to ST1928, ST1899, and ST2092), ST1508 has a more marked dopaminergic profile than that of its direct structural analogues ST1899 ST1928 and ST2092.
TABLE 3 5-HT 2 /D 2 5-HT 2a D 1 D 2 D 3 Ratio pKi Compound pKi pKi pKi pKi values LogY Clozapine 8.00 6.45 6.60 6.50 1.21 3.89 Olanzapine 8.4 7.07 7.16 7.41 1.17 4.69 Haloperidol 6.78 318 8.32 7.74 0.82 9.14 ST1508 9.47 8.72 9.37 8.70 1.01 8.20 ST1899 9.19 7.71 7.76 8.08 1.18 4.98 ST1928 9.46 8.11 8.07 8.57 1.17 5.36 ST2092 8.95 6.81 6.9 7.74 1.30 3.19
[0138] These results render the compounds ST1899 ST1928 and ST2092 particularly useful in the treatment of positive and negative symptoms of schizophrenia.
[0139] Evaluation of Catalepsy
[0140] By means of the test used for evaluating catalepsy in the rat, ST1699 affinity for the D 2 receptor subtype of the nigrostriatal dopaminergic system was verified.
[0141] Table 4 gives the percentages of animals presenting catalepsy at the various different times after administration of subacute doses of the study compound.
TABLE 4 Time (minutes) of catalepsy evaluation after Administration mg/kg 30 min 60 min 90 min 120 min 180 min ST1699 0.6 33 66 83 100 100 0.3 0 0 17 17 33 0.15 0 0 0 0 0 Haloperidol 0.2 0 70 100 100 100
[0142] The product ST1699 induced the occurrence of catalepsy as a result of the highest dose among those used (0.6 mg/kg). The effects were comparable to those induced by 0.2 mg/kg of haloperidol.
[0143] The occurrence of catalepsy only as a result of the highest dose may indirectly verify the ability of the compound exemplified by ST1699 to interact with the 5-HT 2a receptor. In fact, the antagonism to the above-mentioned receptor modulates the dopaminergic activity of the nigrostriatal system, thus limiting the possibility of the occurrence of catalepsy.
[0144] Thus, on the strength of these results and its substantial receptor affinity, the compound ST1508, alias ST1699, proves to be a classic antipsychotic agent in which the dose necessary to obtain an effective therapeutic response can be significantly reduced. Thanks to this potential, the prolonged use of this product, in chronic diseases such as schizophrenia, would be associated with a better tolerability.
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Compounds with formula (I) are described where the groups are as defined here below, as well as processes for their preparation, pharmaceutical compositions containing them and their use for the preparation of medicaments with antipsychotic activity.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to drinking vessels, and particularly to drinking vessels having a self-contained source of illumination.
[0002] It is known to provide a drinking vessel with a self-contained source of illumination to light the drinking vessel in the dark. Lighted drinking vessels commonly include a lamp of the light-emitting diode (LED) or incandescent type, a battery, and an electrical switch and circuit to control the flow of current between the battery and the lamp.
[0003] Illuminated drinking vessels have been an object of interest for more than fifty years, as exemplified by the following patents:
Patent No. Inventor Issue Date 2,224,319 Schroyer Dec. 10, 1940 2,663,866 Simpson Aug. 23, 1951 4,390,928 Runge Jun. 28, 1983 4,922,355 Dietz et al. May 1, 1990 5,070,435 Weller Dec. 3, 1991 5,119,279 Makowsky Jun. 2, 1992 5,211,699 Tipton May 18, 1993 5,339,548 Russell Aug. 23, 1994 5,504,663 Tucker Apr. 2, 1996
SUMMARY OF THE INVENTION
[0004] The present invention provides an illuminated drinking vessel including a lower wall, and a side wall having fluorescent pigment. An ultraviolet light-emitting diode is proximate the lower wall to illuminate the fluorescent pigment. The drinking vessel further includes an electrical power source and an electrical switch for selectively controlling the flow of electrical current between the power source and light-emitting diode.
[0005] Other aspects of the present invention will be apparent from the following description of preferred embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a side view of one embodiment of an ultraviolet illuminated drinking vessel with a wall having fluorescent pigment, shown in cross-section.
[0007] [0007]FIG. 2 is an exploded view of the drinking vessel of FIG. 1.
[0008] [0008]FIG. 3 is a top view of the printed circuit board shown in FIGS. 1 and 2.
[0009] [0009]FIG. 4 is an electrical schematic of the flasher circuit in the drinking vessel of FIGS. 1 and 2.
[0010] [0010]FIG. 5 is a side view of another embodiment of an ultraviolet illuminated drinking vessel with a wall having fluorescent pigment, shown in cross-section.
[0011] [0011]FIG. 6 is an exploded view of the drinking vessel of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
[0013] Referring to FIG. 1 as well as to the exploded view of FIG. 2, one embodiment of the present invention is a lighted drinking vessel or shot glass 10 that includes a main body 12 and a base member 14 which are molded separately and which enclose an impact-responsive indicator circuit 16 . Main body 12 includes an integral lower wall 18 and side wall 20 that define a receptacle for liquid and that cooperate with base member 14 to form a hollow base. Walls 18 and 20 , together with a side wall 22 and a bottom wall 24 of base member 14 , define a compartment 26 for the indicator circuit. Main body 12 is frustoconical and base member 14 is generally cylindrical as illustrated, but either one may have either shape. The main body and base member are both preferably molded of high-impact polystyrene. Further details on a shot glass of the type described above may be found in U.S. Pat. Nos. 5,772,065 to Kalamaras, which patent is hereby incorporated by reference.
[0014] Main body 12 is constructed of a transparent or translucent molded plastic material and is illuminated by a light source, which may be flashing or blinking, located within base member 14 . As preferred, the plastic material of at least side wall 20 and preferably all of main body 12 has fluorescent pigment mixed therein prior to molding. In an alternative configuration that may be desirable for some applications, the fluorescent pigment may be applied as a coating to the outer surface of the side wall 20 . The light source within base member 14 is an ultraviolet light emitting diode (UV LED). The ultraviolet light excites the fluorescent pigment and causes the main body 12 to glow, creating a novel and pleasing aesthetic effect, and also illuminating adjacent surfaces in low-light conditions.
[0015] The fully assembled shot glass of FIG. 1 has an overall height of about 55-60 mm. As shown in the drawing, the floor of compartment 26 is 1.5 mm below the bottom edge 28 of side wall 20 , and the ceiling is 9.5 mm above edge 28 , for a total inside height of 11 mm. Although these are the preferred dimensions, it will be understood that some variation thereof is contemplated for any given size of shot glass and that other sizes of shot glasses are contemplated. Indicator circuit 16 in the disclosed embodiment has an overall height of about 8 mm.
[0016] The separately molded parts of the shot glass may be adhesively bonded together or may be attached by means of a snap-fit connection. In one form of snap-fit connection, the inner surface of side wall 20 is provided with an annular projection or ridge and the outer surface of side wall 22 is provided with a corresponding annular groove, or vice versa. The ridge may extend completely or partially around the circumference of the side wall 20 , and in this case there may be a set of circumferentially spaced ridges. Alternatively, the mating side wall surfaces may both be provided with annular projections adapted to momentarily compress or bend each other as one is forced over the other to snap the two parts of the shot glass together. As another alternative, a set of circumferentially spaced interlocking projections may be provided on each of side walls 20 and 22 and arranged such that the respective projections in each set are offset from each other circumferentially for insertion of the base member into the main body and then rotated with respect to each other in “bayonet” fashion to achieve mutual locking engagement. Although not preferred, the base members may alternatively be joined by ultrasonic welding, in which case energy-directing beads may be required on the mating surfaces as described in the above-referenced U.S. Pat. No. 5,772,065.
[0017] Referring now also to FIGS. 3 - 4 , the indicator circuit in the illustrated embodiment is a flasher circuit and includes a low-profile inertial switch 30 having a cantilevered coil spring contact 32 directly mounted on a printed circuit (pc) board 34 and oriented with the longitudinal axis of the coil spring parallel to the plane of the pc board and perpendicular to the longitudinal axis of the shot glass. The flasher circuit includes inertial switch 30 , an integrated circuit (IC) 36 , an ultraviolet (UV) LED 38 , two button cells 40 a,b in respective battery holders 42 a,b, and associated resistors 44 and 46 , all interconnected as shown in FIG. 3 and all mounted on the circuit board, which may be secured to lower wall 24 by double-backed tape. Suitable dimensions for the pc board are 0.8 mm thickness and 23 mm diameter. The inertial switch as shown is a normally open switch, and IC 36 is triggered by closure of the switch to supply a flashing signal to the UV LED. The IC preferably operates in one-shot mode, whereby it continues to generate an output signal once triggered by the switch, and preferably generates a train of pulses in response to a trigger pulse from the switch.
[0018] The IC is preferably supplied in die form and wire bonded to the upper surface of the circuit board. A suitable IC for the flasher circuit is type HKA-5417, also identified as A5417, commercially available from Hua Ko Electronics Co. Ltd., Hong Kong. The IC generates a pulse train of 38 pulses each time it is triggered, at a rate and with a pulse width controlled by timing resistor 46 . The timing resistor value is preferably selected so that the IC generates approximately 2 pulses per second with a pulse width of approximately 100 milliseconds. Proportionately different pulse widths and rates may be obtained if desired by selecting a different value for resistor 46 . Further details of a suitable circuit design may be found in U.S. Pat. No. 6,419,384 to Lewis et al., which patent is hereby incorporated by reference.
[0019] UV LED 38 emits light having a wavelength in the range of about 390 to about 410 nm, more preferably having a peak of about 390 nm to about 410 nm, and most preferably having a peak of about 400 nm. A suitable UV LED is the DL50PLDW503 UV LED available from Shue Kwong Optic Electronic Company, Shenzhen, China. The ultraviolet light is collected by lower wall 18 and transmitted throughout the plastic material that comprises lower wall 18 and side wall 20 of main body 12 . The intensity of the illumination may diminish somewhat along the length of side wall 20 , due to increased attenuation of the ultraviolet light as it passes through the plastic material, resulting in the brightness of the visible light emitted from side wall 20 diminishing over the length of shot glass 10 toward the rim. The visual effect may be enhanced, if desired, with an upwardly oriented parabolic or otherwise curved reflector around the UV LED. A flat reflector is also useful around the LED.
[0020] The above-described combination of a UV LED and fluorescent pigment in a shot glass is particularly advantageous with a dark alcoholic beverage or other liquid in the glass. Dark liquids tend to absorb the light emitted from a light source in the base and thereby degrade the illumination. However, UV light transmits through the dark liquid and/or through the plastic body of the shot glass and, in combination with the fluorescent pigment, causes the side wall to glow and thereby remain highly visible despite the contents of the glass.
[0021] The plastic material of side wall 20 and lower wall 18 can be a polycarbonate material that is mixed with fluorescent pigment and injection molded into the shape of shot glass 10 . Alternatively, the plastic material may be polystyrene, PVC, ABS or acrylic materials. The pigment may be mixed at a ratio of about 1 to 2 grams of pigment per kilogram of plastic material. The fluorescent pigment may be a pigment that is commercially available from Wen Lee Plastic Pigment Company, Tungguong, China, such as Part No. 61113 (green), Part No. 31461 (blue), Part No. 238 (red), or Part No. 2600 (yellow). As discussed above, in an alternative configuration that may be desirable for some applications, the fluorescent pigments may be applied as a coating to the outer surface of the side wall 20 .
[0022] An alternative circuit configuration suitable for certain applications including larger drinking vessels such as tumblers is disclosed in copending U.S. patent application Ser. No. 08/730,597 and is incorporated herein by reference. In addition, the invention may alternatively be embodied in plastic mugs and miniature martini glasses.
[0023] Another embodiment of the present invention is shown in FIGS. 5 and 6 in which drinking vessel or shot glass 110 is similar to shot glass 10 described above, except as further described below. Shot glass 110 has an overall height of about 76 mm and a maximum diameter of about 36 mm, and is frustoconical but with a shallower taper than that of shot glass 10 . Main body 112 and base member 114 together enclose an impact-responsive indicator circuit 116 of the same type as circuit 16 described above. Main body 112 is preferably bayonet mounted to base member 114 , i.e., by means of a press- and-twist interlocking connection. More specifically, the bottom portion 128 of side wall 120 may have two small projections engaging respective L-shaped grooves formed in the inside surface of side wall 122 . Other types of connections as described above for shot glass 10 may be employed as alternatives.
[0024] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. For example, it is also contemplated that fluorescein dye may be mixed with ink to be applied to a surface of the main body of the drinking vessel to form a logo or other indicia desired to be illuminated.
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An illuminated drinking vessel includes a main body with a side wall having fluorescent pigment. An ultraviolet light-emitting diode illuminates the fluorescent pigment. The drinking vessel includes an electrical power source such as a button cell and an electrical switch for selectively controlling the flow of electrical current between the power source and light-emitting diode. A base member connected to the main body contains the power source, the electrical switch, and the ultraviolet light-emitting diode. The fluorescent pigment of the side wall emits visible light in response to being illuminated by ultraviolet light.
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RELATED APPLICATIONS
This utility patent application claims the benefit under 35 United States Code §119(e) of U.S. Provisional Patent Application No. 60/742,240 filed on Dec. 5, 2005, which is hereby incorporated by reference in its entirety.
BACKGROUND
Some application developers desire to customize their applications to interoperate with certain widely-used existing applications such as: word-processing applications; email applications; and the like. In some instances, the application developer would like to provide a user interface that is customized for an application but that can still be easily modified or extended as the application changes. Today, the application developer hard codes this functionality into the application making it cumbersome to change and update.
SUMMARY
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
Metadata is defined to create customized user interface (UI) portions for an application. The metadata is created according to a metadata schema that defines mechanisms for data binding application data to the controls of the UI. The metadata may be XML-based and is interpreted and then rendered to implement a customized UI that also supports data binding between data and the UI controls. For example, an application developer can write a metadata file that defines basic as well as custom UI controls, properties of the controls, layout of the controls, and the like. Once created, the metadata is processed by a rendering engine to display the UI controls. An interpreter may be used to interpret the metadata file before it sent to the rendering engine. Neither the rendering engine nor the interpreter needs knowledge of the host application and provides support for arbitrary metadata driven UI. The metadata schema may include mechanisms to create custom controls for the UI; programmatically modify the UI controls by providing access to a code-behind assembly as well as support event handling for the UI controls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary computing environment;
FIG. 2 shows a user interface metadata system;
FIGS. 3A and 3B show an example UI form that is described by a metadata file;
FIG. 4 illustrates a process for using metadata to describe a UI form; and
FIG. 5 show a process for rendering a UI form with associated metadata.
DETAILED DESCRIPTION
Referring now to the drawings, in which like numerals represent like elements, various embodiments will be described. In particular, FIG. 1 and the corresponding discussion are intended to provide a brief, general description of a suitable computing environment in which embodiments may be implemented.
Generally, program modules include routines, programs, components, data structures, and other types of structures that perform particular tasks or implement particular abstract data types. Other computer system configurations may also be used, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. Distributed computing environments may also be used where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
FIG. 1 illustrates an exemplary computer environment 100 , which can be used to implement the techniques described herein. The computer environment 100 is only one example of a computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the computer and network architectures. Neither should the computer environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the example computer environment 100 .
Computer environment 100 includes a general-purpose computing device in the form of a computer 102 . The components of computer 102 can include, but are not limited to, one or more processors or processing units 104 , system memory 106 , and system bus 108 that couples various system components including processor 104 to system memory 106 .
System bus 108 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, such architectures can include an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MCA) bus, an Enhanced ISA (EISA) bus, a Video Electronics Standards Association (VESA) local bus, a Peripheral Component Interconnects (PCI) bus also known as a Mezzanine bus, a PCI Express bus, a Universal Serial Bus (USB), a Secure Digital (SD) bus, or an IEEE 1394 , i.e., FireWire, bus.
Computer 102 may include a variety of computer readable media. Such media can be any available media that is accessible by computer 102 and includes both volatile and non-volatile media, removable and non-removable media.
System memory 106 includes computer readable media in the form of volatile memory, such as random access memory (RAM) 110 ; and/or non-volatile memory, such as read only memory (ROM) 112 or flash RAM. Basic input/output system (BIOS) 114 , containing the basic routines that help to transfer information between elements within computer 102 , such as during start-up, is stored in ROM 112 or flash RAM. RAM 110 typically contains data and/or program modules that are immediately accessible to and/or presently operated on by processing unit 104 .
Computer 102 may also include other removable/non-removable, volatile/non-volatile computer storage media. By way of example, FIG. 1 illustrates hard disk drive 116 for reading from and writing to a non-removable, non-volatile magnetic media (not shown), magnetic disk drive 118 for reading from and writing to removable, non-volatile magnetic disk 120 (e.g., a “floppy disk”), and optical disk drive 122 for reading from and/or writing to a removable, non-volatile optical disk 124 such as a CD-ROM, DVD-ROM, or other optical media. Hard disk drive 116 , magnetic disk drive 118 , and optical disk drive 122 are each connected to system bus 108 by one or more data media interfaces 125 . Alternatively, hard disk drive 116 , magnetic disk drive 118 , and optical disk drive 122 can be connected to the system bus 108 by one or more interfaces (not shown).
The disk drives and their associated computer-readable media provide non-volatile storage of computer readable instructions, data structures, program modules, and other data for computer 102 . Although the example illustrates a hard disk 116 , removable magnetic disk 120 , and removable optical disk 124 , it is appreciated that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes or other magnetic storage devices, flash memory cards, CD-ROM, digital versatile disks (DVD) or other optical storage, random access memories (RAM), read only memories (ROM), electrically erasable programmable read-only memory (EEPROM), and the like, can also be utilized to implement the example computing system and environment.
Any number of program modules can be stored on hard disk 116 , magnetic disk 120 , optical disk 124 , ROM 112 , and/or RAM 110 , including by way of example, operating system 126 (which in some embodiments include low and high priority I/O file systems and indexing systems described above), one or more application programs 128 , interpreter 192 , and rendering engine 192 . Each of such operating system 126 , one or more application programs 128 , a metadata interpreter 190 , a UI rendering engine 192 and metadata 133 (or some combination thereof) may implement all or part of the resident components. The metadata repository 133 includes information that allows the customization of UI elements on a UI that is associated with application programs 128 . For example, the metadata can include information that allows the customization of UI forms for UI 164 that is displayed on monitor 142 . The metadata repository 133 may include information for multiple applications on various coupled computing devices.
A user can enter commands and information into computer 102 via input devices such as keyboard 134 and a pointing device 136 (e.g., a “mouse”). Other input devices 138 (not shown specifically) may include a microphone, joystick, game pad, satellite dish, serial port, scanner, and/or the like. These and other input devices are connected to processing unit 104 via input/output interfaces 140 that are coupled to system bus 108 , but may be connected by other interface and bus structures, such as a parallel port, game port, or a universal serial bus (USB).
Monitor 142 or other type of display device can also be connected to the system bus 108 via an interface, such as video adapter 144 . In addition to monitor 142 , other output peripheral devices can include components such as speakers (not shown) and printer 146 which can be connected to computer 102 via I/O interfaces 140 .
Computer 102 can operate in a networked environment using logical connections to one or more remote computers, such as remote computing device 148 . By way of example, remote computing device 148 can be a PC, portable computer, a server, a router, a network computer, a peer device or other common network node, and the like. Remote computing device 148 is illustrated as a portable computer that can include many or all of the elements and features described herein relative to computer 102 .
Logical connections between computer 102 and remote computer 148 are depicted as a local area network (LAN) 150 and a general wide area network (WAN) 152 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet.
When implemented in a LAN networking environment, computer 102 is connected to local network 150 via network interface or adapter 154 . When implemented in a WAN networking environment, computer 102 typically includes modem 156 or other means for establishing communications over wide network 152 . Modem 156 , which can be internal or external to computer 102 , can be connected to system bus 108 via I/O interfaces 140 or other appropriate mechanisms. The illustrated network connections are examples and that other means of establishing at least one communication link between computers 102 and 148 can be employed.
In a networked environment, such as that illustrated with computing environment 100 , program modules depicted relative to computer 102 , or portions thereof, may be stored in a remote memory storage device. By way of example, remote application programs 158 reside on a memory device of remote computer 148 . For purposes of illustration, applications or programs and other executable program components such as the operating system are illustrated herein as discrete blocks, although it is recognized that such programs and components reside at various times in different storage components of computing device 102 , and are executed by at least one data processor of the computer.
Various modules and techniques may be described herein in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. for performing particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.
An implementation of these modules and techniques may be stored on or transmitted across some form of computer readable media. Computer readable media can be any available media that can be accessed by a computer. By way of example, and not limitation, computer readable media may comprise “computer storage media” and “communications media.”
“Computer storage media” includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer.
“Communication media” typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as carrier wave or other transport mechanism. Communication media also includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. As a non-limiting example only, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above are also included within the scope of computer readable media.
FIG. 2 shows a user interface metadata system. As illustrated, system 200 includes metadata 210 , interpreter 220 , code-behind assembly 225 , rendering engine 230 that renders user interface 240 and back-end data source 250 . Initially, a developer, or some other user, specifies metadata 210 for a given UT Form. Generally, once the metadata has been created and specified, the interpreter 220 accesses the metadata and then passes the UI information to rendering engine 230 such that the UI 240 may be displayed to a user. Although interpreter 220 is illustrated separately from rendering engine 230 its functionality may be included within rendering engine 230 as illustrated by the dashed box surrounding the interpreter 220 and rendering engine 230 .
Metadata 210 allows the developer to specify a set of events 215 for each control 241 - 243 that are included on the user interface 240 . The metadata 210 allows the UI forms developer to specify the controls to be added to the UI; define custom events on these added controls (or add events to the existing controls); and define the event-handlers via code in a code-behind assembly 225 for these new custom events (or modify existing custom-handlers by overriding the default behavior). An Object Model (OM) is exposed that allows the developer to read/modify properties of the controls on the form such that the event-handlers are defined in the code behind assembly 225 . The name and location of the code-behind assembly 225 is captured as part of the metadata 210 .
According to one embodiment, the events mirror the typical events supported for the same type of control in a WINFORMS environment. In addition to the standard events that may be initially supported by a control, additional controls and custom events may be added through the metadata 210 .
As illustrated, the rendering engine 230 receives the metadata defining the UI through interpreter 220 and renders the UI form 240 . According to one embodiment, rendering engine 230 renders the UT form either in an IBF task pane or a MICROSOFT OUTLOOK custom form. According to this embodiment, the rendering engine 230 creates a .NET control object correpsonding to the UT that is defined by the metadata 210 and that .NET control is hosted either in the IBF task pane or OUTLOOK custom form. In this embodiment, the rendering engine 230 parses the metadata that is supplied by interpreter 220 and instantiates the different controls (i.e. 241 - 243 ) that are described by metadata 210 and outputs a .NET control describing the UI form.
According to one embodiment, the rendering engine 230 provides ten basic controls which the UI forms developer can use while designing a UI form using metadata
These ten basic controls include: Panel; Label; LinkLabel; TextBox; Button; ListBox; ComboBox; RadioButton; CheckBox and an Image control. As discussed previously, custom control and events may also be created. Other basic controls may also be provided.
Each control includes a wrapper class which wraps the control (i.e. a native WINFORM (.NET) control). The wrapper provides functionality for data binding and exposing control properties to the code behind assembly 225 through a programmatic object model (OM). The following is an exemplary wrapper class for a textbox control:
internal class XamlTextBox : XamlControl, IXamlTextBox
{
// Native winform (.NET) control
private TextBox textBox = null;
---
}
The ‘IXamlTextBox’ interface exposes TextBox specific properties to the code behind file. An application developer can access a textbox control on the UI in the code behind using the ‘IXamlTextBox’ interface and read/write the control properties.
The ‘XamlControl’ provides the base class for the controls rendered by the rendering engine 230 .
internal class XamlControl : IXamlControl, IBindable
{
// Native winform (.NET) control
protected Control Control = null;
}
The ‘IXamlControl’ interface exposes the control to the code behind file. An application developer can access properties of a control through this interface in the code behind assembly 225 . The ‘IBindable’ interface is used by the ‘Binder’ component to set control properties which are bound to properties in a data source. The ‘XamlControl’ class receives the pseudo XAML metadata (XML) defining the control and then it instantiates the native .NET WINFORM control (depending upon type) and sets the control properties specified in the metadata for the control.
public XamlControl(XmlNode nodeXml, IControlParent parent, string
type)
{
this.Control = CreateControl(type);
...
}
When the rendering engine 230 receives the pseudo XAML metadata defining a UI form it reads/parses the input XML and instantiates the wrapper classes for the controls passing in the metadata defining the control. According to one embodiment, the parsing is done in a depth first manner. Other methods may also be used. The wrapper class instantiates the native WINFORM (.NET) control and sets the control properties as defined in the metadata. A wrapper class for each control sets the control properties as specified in the metadata. The base ‘XamlControl’ class sets the properties which are common to every control (for e.g. Background, Foreground, Anchor, Font etc). The specific derived classes such as: ‘XamlTextBox’ handles the control (textbox) specific properties. If a particular control property is bound to a property in a data source, such as data source 250 , then the wrapper class passes the control, property name and binding expression to the ‘Binder,’ which then gets the property value from the data source and then sets the specific control property through the ‘IBindable’ interface. The wrapper class for each control also subscribes to the control events (SubscribeToEvents()) exposed by the pseudo XAML metadata. When an event on a control fires then the rendering engine 230 forwards the event to the event handler defined in the code behind assembly 225 . The wrapper class also calls a ‘GetChildControls()’ method which instantiates the child controls for the control.
Event handlers 226 may be developed for control events occurring on the form. To handle a specific event on a control, the developer performs steps, including: developing a code behind assembly 225 which contains the event handler code; specifying the code behind assembly in the metadata; and specifying the event handler (method) name which handles a particular event for a control. According to one embodiment, to specify an event handler in the metadata for an event on a control the developer supplies the event handler method name present in the code behind assembly as the value of the attribute corresponding to the event on the control. The metadata 210 specifies that the “Click” event for the Button control is handled by the method “ButtonClick” which is present as a public method in the code behind assembly. According to one embodiment, the signature for the event handler is same as what it would be for that event on that particular control in case of .NET WINFORMS environment. For example, the event handler for the click event on a Button would have the following signature: public void ButtonClick(object sender, System.EventArgs e) { }. According to one embodiment, this is the same signature as the original button control which provides for programmer understanding and consistency.
Rendering engine 230 loads the code behind assembly 225 when it parses the metadata 210 provided by interpreter 220 and instantiates the code behind class through reflection. The events that are exposed through the metadata on a control are subscribed to when that control is instantiated during parsing of the metadata. In one implementation the event handlers for control events bubble up the event to the “Page” level and then the event handler in the code behind assembly is called through reflection. More than one “code behind” assembly can be associated to a “page” or form. Providing more than one “code behind” assembly allows for multiple levels (multiple parties) of extensibility.
Data may also be bound to one or more of the controls (e.g. controls 241 - 243 ) from a backend data source 250 . According to one embodiment, the binding expressions that bind data source 250 to one or more of the controls (e.g controls 241 - 243 ) are specified in the metadata. Each property of a control (i.e. controls 241 - 243 ) can be bound to data coming from a data source. Thus, the data source changes control properties that are associated with the controls when the data source 250 is changed. More than one data source may be bound. For example, control 1 ( 241 ) could be bound to one data source while control 2 ( 242 ) is bound to a different data source. According to one embodiment, there are two different types of data sources, including an object data source and an XML data source. An object data source is a .NET class residing in a .NET assembly which acts as a data source for controls on the UI. An XML Data Source acts as a source of XML data which is specified inline in the XAML metadata defining the UI.
According to one embodiment, an object data source can be specified in the metadata in the following manner: <xaml:ObjectDataSource Name=“myDataSource” TypeName=“DataSourceNamespace.DataSourceClass, DataSourceAssembly”/>The “DataSourceClass” implements the “IBindData” and “INotifyPropertyChanged” interfaces. Exemplary embodiments of these interfaces are described below:
public interface IBindData
{
object GetData(string path); // gather data
bool SetData(string path, object val); // scatter data
}
In this embodiment, the “IBindData” interface allows to bind data between the data source and control properties (explained below) through the standard .NET event delegate model.
public interface INotifyPropertyChanged
{
event PropertyChangedEventHandler PropertyChanged;
}
public delegate void PropertyChangedEventHandler(object sender,
PropertyChangedEventArgs e);
public class PropertyChangedEventArgs : System.EventArgs
{
public virtual string PropertyName {get; }
}
The “INotifyPropertyChanged” interface allows the data source to signal any changes that happen on the data source so that the UI properties which are bound to that data source can be updated. The data source raises the “PropertyChanged” event whenever a property in the data source changes. The relevant properties on the UI are then updated whenever this event fires. Once the data sources are specified in the metadata then any property of a control can be bound to data coming from a data source.
To specify a binding for a control property the developer supplies a binding expression as the value of the attribute corresponding to that property. For example, to bind the “Text” property of a text box, the developer can specify a binding expression in the metadata 210 as follows: <xaml:TextBox Name=“textBox1” Top=“40” Left=“8” Width=“200”Text=“{Binding Source=DataSourceName, Path=CustomerName, Mode=TwoWay}” Anchor=“Top,Left,Right”/>The expression Text=“{Binding Source=DataSourceName, Path=CustomerName, Mode=TwoWay}” is a binding expression for the ‘Text’ property. The ‘Source’ clause refers to a data source defined in the metadata. This could be an Object data Source or XML Data Source. In case of Object Data Source the value of the ‘Path’ clause is passed to the data source's “GetData(string path)” method when retrieving the value for the bound property. For an XML Data source the ‘Path’ clause is an Xpath expression in this embodiment, which selects a particular node/attribute in the XML data whose value would be the bound to the control property. The ‘Mode’ clause indicates ‘OneWay’ or ‘TwoWay’ binding. If the data flows from the data source to controls on the UI then the binding is ‘OneWay’ but if UI property changes are also propagated back to the data source then the binding is ‘TwoWay’. The ‘UpdateSourceTrigger’ is an enumeration which specifies when (what event) to signal the data source that a UI property has changed and the changed property value needs to be propagated to the data source. By default, in this embodiment, the value for this clause is ‘PropertyChanged’ which means that when a bound property changes then it is signaled to the data source. According to one embodiment, this only takes effect in case of ‘TwoWay’ binding.
The ‘ItemsSource’ attribute of a List Control allows binding of the items in the list to a collection of objects coming from a data source. When the ‘ItemsSource’ property is bound then the data source returns a .NET collection implementing the ‘System.Collections.IEnumerable’ interface. The ‘DisplayMemberPath’ attribute of the List Control specfies the property of the .NET object(s) which form the collection whose value is used as the display text for the item in the list control. If the ‘DisplayMemberPath’ is null then the default ‘ToString()’ method is called on the .NET object and the string returned is used as the display text. For example, suppose the data source returns a collection of ‘Customer’ objects which are shown in the list control then the ‘Customer’ object may have a ‘Name’ property whose value is to be used as the display text in the list control. In this case the ‘DisplayMemberPath’ is set to ‘Name.’ Similarly ‘SelectedValuePath’ is set to the property of the .NET object(s) forming the collection whose value is returned by the ‘SelectedValue’ property of the list control when a particular item is selected in the list control. For example, suppose that the ‘Customer’ object has a ‘CustomerID’ property whose value is returned by the ‘SelectedValue’ property when the ‘SelectedValuePath’ property of the list control is set to ‘CustomerID.’ If no ‘SelectedValuePath’ attribute is provided then the whole object (‘Customer’ object) is returned by the ‘SelectedValue’ property of the list control.
In case of a XML Data Source, the binding expression for ‘ItemsSource’ attribute of a list control returns a list of XML nodes. For example, assume that the following is an XML data source:
<XmlDataSource Name=“BookData”>
<Books xmlns=“”>
<Book ISBN=“0-7356-0562-9” Stock=“in”>
<Title>XML in Action</Title>
<Summary>XML Web Technology</Summary>
</Book>
<Book ISBN=“0-7356-1370-2” Stock=“in”>
<Title>Programming Microsoft Windows With C#</Title>
<Summary>C# Programming using the .NET Framework
</Summary>
</Book>
<Book ISBN=“0-7356-1288-9” Stock=“out”>
<Title>Inside C#</Title>
<Summary>C# Language Programming</Summary>
</Book>
<Book ISBN=“0-7356-1377-X” Stock=“in”>
<Title>Introducing Microsoft .NET</Title>
<Summary>Overview of .NET Technology</Summary>
</Book>
<Book ISBN=“0-7356-1448-2” Stock=“out”>
<Title>Microsoft C# Language Specifications</Title>
<Summary>The C# language definition</Summary>
</Book>
</Books>
</XmlDataSource>
The binding expression for the ‘ItemsSource’ property of a list which shows the list of books is: <ListBox ItemsSource=“{Binding Source=BookData, Path=/Books/Book}”/> The ‘Path’ clause in the above binding expression is actually an Xpath expression which returns a list of nodes which are populated in the list control from the XML Data Source. The ‘DisplayMemberPath’ attribute of the list control should be an Xpath (in case of XmlDataSource) which selects the node/attribute whose value is to be used as the display text in the list control. For example, if the UI forms developer wants to display the ‘Title’ for each book in the list control, then the user's XML would look like: <ListBox ItemsSource=“{Binding Source=BookData, Path=/Books/Book}” DisplayMemberPath=“Title”/> Similarly, the ‘SelectedValuePath’ attribute of the list control points to the node/attribute of the list item whose value is returned by the ‘SelectedValue’ attribute of the list.
For example, suppose that the UI forms developer wants to return the ‘ISBN’ value for a book in the ‘SelectedValue’ property of the list control when a particular book is selected in the list, then the ‘SelectedValuePath’ attribute may be an Xpath pointing to the ‘ISBN’ attribute of the book item.
<ListBox ItemsSource=“{Binding Source=BookData, Path=/Books/Book}” DisplayMemberPath=“Title” SelectedValuePath=“@ISBN”/>
Controls utilizing data binding implement the ‘IBindable’ interface as illustrated below:
public interface IBindable
{
object GetBoundValue(string propName);
void SetBoundValue(string propName, object val);
}
When the UI form 240 is initially rendered then for every bound property the ‘GetData(string path)’ method of the relevant data source (specified in the binding expression) is called passing in the value of the ‘Path’ clause in the binding expression as an argument. This method returns a value of type ‘object.’ Next, the ‘SetBoundValue(string propName, object value)’ is called on the control whose property is bound passing in the name of the bound property and the ‘value’ returned by the data source. The control has the responsibility for understanding the ‘value’ object and interpreting it to update the bound property. Besides the initial rendering of the UI form whenever the data source changes the data source signals the binder of a change in data source (INotifyPropertyChanged). The binder finds out which control properties are bound to the changed data source and updates those properties. In the case of ‘TwoWay’ binding then whenever a bound UI property changes on the UI form then the binder is notified and the binder then propagates the changed property value back to the data source.
As discussed briefly above, the rendering engine 230 also provides a generic framework for hosting custom built controls. According to one embodiment, the framework supports custom .NET winform controls. According to one embodiment, any custom controls derive from the class: ‘System.Windows.Forms.UserControl.’ Each custom control has a default contructor and also implements the ICustomControl interface and the ‘IBindable’ interface so that it can participate in data binding. The following is an exemplary ‘ICustomControl’ interface:
public interface ICustomControl
{
void SetControlProperty(string propName, string propValue);
event ControlEventFiredHandler ControlEventFired;
}
public delegate void ControlEventFiredHandler(object sender,
ControlEventFiredArgs e);
public class ControlEventFiredArgs : System.EventArgs
{
public string EventName {get;}
public object Sender { get; }
public object EventArgs {get;}
}
The ‘SetControlProperty(string propName, string propValue)’ method is used by the rendering engine 230 to set custom properties for the control. For each custom property which the custom control exposes and which is not included in the basic properties of a control (e.g. Width, Height, Top, Left etc) the rendering engine 230 calls the ‘SetControlProperty’ method on the custom control and it is up to the custom control to understand and interpret the ‘string’ property value that is specified in the metadata which would be passed to the ‘SetControlProperty’ method.
The ‘ControlEventFired’ event is raised by the custom control when a custom event exposed by the control fires. This is to signal the rendering engine 230 that an event has fired on the custom control and the rendering engine needs to call the event handler (if any) for that event in the code behind assembly 225 . The rendering engine
does not know at compile time what are the events (and event signatures) supported by the custom control. As such, the rendering engine 230 requires the custom control to notify it when a custom event fires on the custom control. The custom control creates an instance of the ‘ControlEventFiredArgs’ class and passes it to the ‘ControlEventFired’ event which is received by the rendering engine 230 . The ‘ControlEventFiredArgs’ contains information about the name of the event which fired, sender and event arguments which need to be passed to the event handler for that event. Once the rendering engine 230 has this information it can call the event handler for that event specified in the code behind assembly 225 .
According to one embodiment, the custom controls reside in a .NET assembly at run time. The custom control assembly in the metadata may be specified in the following way: <xaml:Mapping XmlNamespace=“urn-Mendocino/CustomControls” ClrNamespace=“CustomControlNamespace” Assembly=“CustomControlAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null”/> The ‘Mapping’ element is a processing directive rather than an XML element. Other ways of specifying the custom control assembly may also be utilized.
A custom control can be specified in the metadata through the following exemplary metadata: <custom:CustomControl xmlns:custom=“urn-Mendocino/CustomControls” Top=“0” Left=“0” Height=“100” Width=“100” . . . /> In this embodiment, the rendering engine 230 instantiates the custom control through reflection and first set the basic properties of a control like Height, Width, Top, Left, and the like and then for other properties (custom properties) the rendering engine 230 calls the ‘SetControlProperty()’ method on the custom control.
A mechanism within the metadata schema allows the UI forms developer to access the UI controls and their properties in the code behind assembly. The code behind class implements the ‘IPageCodeBehind’ interface which is described below:
public interface IPageCodeBehind
{
string Name { get; set; }
IPageControlCollection PageControls { get; set; }
object Application { get; set; }
object Mediator {get; set; }
object ReturnValue { get; set; }
}
The ‘PageControls’ property is populated by the rendering engine 230 when it renders the UI form and instantiates the controls. The ‘Application’ property represents the host application (i.e. OUTLOOK) in which the UI forms are being rendered. According to one embodiment, the ‘Mediator’ property allows the code behind developer to execute IBF actions defined in metadata. ‘ReturnValue’ is a variable which can be set by the code behind developer which is passed back to the caller who renders the form. This is used in case of modal dialogs to pass back a value from the dialog to the caller.
The following is an exemplary ‘IPageControlCollection’ interface:
public interface IPageControlCollection : ICollection, IEnumerable
{
IXamlControl this[string name] { get; }
}
The ‘IXamlControl’ interface exposes the properties for a control on the form.
public interface IXamlControl
{
// Properties...
string Name { get;set; }
int Top { get;set; }
int Left { get;set; }
Color Background { get;set; }
bool IsEnabled { get;set; }
int Height { get;set; }
int Width { get;set; }
// Other properties //...
}
This allows the UI forms developer to access a control on the form in the following way: MessageBox.Show(this.PageControls[“myButton”].Text); The ‘IXamiControl’ interface exposes the basic properties of a control that are common to every control. To access specific properties for a control (e.g. IsChecked for a CheckBox control) the developer can cast the ‘IXamlControl’ object to the specific control interface, such as: ‘IXamlCheckBox’, ‘IXamlTextBox’, and the like. ((IXamlCheckBox)this.PageControls[“myCheckBox”]).IsChecked
The following is an exemplary ‘IXamlCheckBox’ interface that derives from the ‘IXamlControl’ interface:
public interface IXamlCheckBox : IXamlControl
{
// CheckBox specific properties...
ContentAlignment TextAlignment {get; set;}
bool IsChecked {get; set;}
}
Similarly specific interfaces for the controls are exposed which allow the UI forms developer to access control specific properties.
According to one embodiment, the rendering engine 230 generates the same .NET control from the metadata describing the UI form irrespective of whether the UI form is hosted in an IBF task pane, an OUTLOOK custom form or a dialog. The following scenarios provide example of how the .NET control may be hosted.
According to one embodiment, the IBF task pane supports hosting any .NET control which implements the ‘IRegion’ interface. The rendering framework contains a blank (empty) .NET control which implements the ‘IRegion’ interface and which hosts the .NET control generated by the UI rendering engine from the UI metadata. To display a metadata defined UI form in the IBF task pane the ‘MSIBF.UI.ShowRegion’ custom operation is used which displays the blank .NET host control part of the UI rendering framework. The input passed to this ‘MSIBF.UI.ShowRegion’ operation is the metadata defining the UI form which is to be hosted in the IBF task pane. The MSIBF.UI.ShowRegion’ operation instantiates the blank host .NET control and passes the metadata defining the UI form as ‘Data’ to the blank host .NET control. The host control calls the rendering engine 230 passing in the metadata defining the UI form and which returns a .NET control describing the UI form and which is then added to the host control resulting in the display of the UI form in the IBF task pane.
According to another embodiment, to host a .NET control describing a UI form in an OUTLOOK an ActiveX container control capable of hosting .NET controls is added to the OUTLOOK form and then the .NET control is added describing the UI form as a child control of the container control. The ActiveX container control is a part of the UI Rendering framework. According to one embodiment, Forms 2.0 hosts the ActiveX containter which hosts the .NET WinForms control described by metdata.
Metadata defined forms may also be created in modal .NET Winform dialogs. In this embodiment, program code, such as that contained within an addin calls the rendering engine 230 passing in the XAML metadata defining a form and the rendering engine 230 passes back the .NET control generated from the XAML metadata which can then be hosted either in the IBF task pane, OUTLOOK Custom Form or a dialog. The addin instantiates an instance of the ‘RenderEngine’ class which implements the ‘IRenderEngine’ interface:
public interface IRenderEngine
{
IXamlPage CreateXamlForm(XmlNode pageXml);
}
The caller can call the ‘CreateXamlForm’ method passing in the XAML metadata describing the form. The rendering engine 230 instantiates the necessary controls and pass back an object (‘IXamIPage’) which represents the ‘xaml’ form.
public interface IXamlPage
{
string Name { get; }
Control NativeControl { get; }
IPageControlCollection Controls { get; }
object ReturnValue { get; }
}
In this embodiment, the ‘NativeControl’ property above represents the .NET control describing the metadata UI form which can be hosted either in the IBF task pane, OUTLOOK custom form or a dialog. The ‘ReturnValue’ property is a variable which can be set from the code behind file and would be used to return a value from a modal dialog.
FIGS. 3A and 3B show an example UI form that is described by a metadata file. Referring to FIG. 3A , UI form 300 includes label 305 , page 310 , panel 315 , text box 320 , check box 325 , link 330 , button 335 , list box 340 and radio button list 345 .
FIG. 3B shows an exemplary UI metadata file 360 that may be used to define the UI form 300 as illustrated in FIG. 3A . The example UI metadata file 360 illustrates that the properties of a control are specified by the attributes of the corresponding XML node. According to one embodiment, most properties have a default value and do not need to be specifically specified. As illustrated in FIG. 3B , indicator 362 shows the description of the panel 310 ; indicator 364 shows the description of the label 305 ; indicator 366 shows the description of textbox 320 ; indicator 368 shows the description of checkbox 325 ; indicator 370 shows the description of button 335 ; indicator 372 shows the description of link 330 ; indicator 374 shows the description of the list box 340 and indicator 376 shows the description of the radio button list 345 .
FIG. 4 illustrates a process for using metadata to describe a UI form. After a start operation, the process moves to operation 410 where the metadata file is defined. As discussed above, the metadata within the file describes the UI and includes information on the controls, the data binding, and other relevant information relating to the user interface.
Moving to operation 420 , the metadata file is stored. According to one embodiment, the metadata file is stored on a computer-readable medium, such as a hard drive. The metadata file may be stored locally and/or remotely from the computing device displaying the related UI.
Transitioning to operation 430 , the metadata file is accessed. According to one embodiment, the metadata file is accessed by a rendering engine. Alternatively, as discussed above, an interpreter may be used to access the metadata file.
Flowing to operation 440 , zero or more data sources may be bound to one or more of the controls defined for the UI through the metadata.
Moving to operation 450 , the metadata is interpreted and then rendered to display the UI. Each control of the UI form is rendered on the UI (see FIG. 5 and related discussion).
The process then moves to an end operation and returns to processing other actions.
FIG. 5 show a process for rendering a UI form with associated metadata. After a start operation, the process moves to operation 510 where a control is instantiated. The control is instantiated based on the type of control (i.e. label, text box, and the like).
Flowing to operation 520 , the base properties of the control are set. For example, the properties such as the top, left, height, width, and the like are set.
Moving to operation 530 the control properties are set. The control properties that are set depend on the type of control.
Next, at operation 540 , the control events that are specified within the metadata are subscribed to. Flowing to operation 550 any child controls for the control are instantiated. The process then moves to an end operation and returns to processing other actions.
The following is an exemplary schema which may be used for defining a UI form using metadata.
<?xml version=“1.0” encoding=“utf-8” ?>
<xs:schema targetNamespace=“urn-Mendocino/xaml”
elementFormDefault=“qualified”
xmlns:xaml=“urn-Mendocino/xaml”
xmlns:xs=“http://www.w3.org/2001/XMLSchema”
<xs:complexType name=“ControlType”>
<xs:attributeGroup ref=“xaml:ControlTypeAttributes” />
</xs:complexType>
<xs:complexType name=“ParentControlType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:sequence>
<xs:element ref=“xaml:Control” minOccurs=“0” maxOccurs=“unbounded”/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“PageType”>
<xs:complexContent>
<xs:extension base=“xaml:ParentControlType”>
<xs:sequence>
<xs:element ref=“xaml:ObjectDataSource”
minOccurs=“0” maxOccurs=“unbounded” />
<xs:element ref=“xaml:XmlDataSource”
minOccurs=“0” maxOccurs=“unbounded” />
</xs:sequence>
<!-- Events -->
<xs:attribute name=“Load” type=“xs:string” use=“optional” />
<!-- Code Behind Assembly -->
<xs:attribute name=“Assembly” type=“xs:string” use=“optional” />
<xs:attribute name=“TypeName” type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“ObjectDataSourceType”>
<xs:attribute name=“Name” type=“xs:string” use=“required” />
<!-- Data source class -->
<xs:attribute name=“TypeName” type=“xs:string” use=“optional” />
<xs:attribute name=“Parameters” type=“xs:string” use=“optional” />
</xs:complexType>
<!-- Inline XML data source-->
<xs:complexType name=“XmlDataSourceType”>
<xs:sequence>
<xs:any processContents=“skip” />
</xs:sequence>
<xs:attribute name=“Name” type=“xs:string” use=“required” />
</xs:complexType>
<xs:complexType name=“PanelType”>
<xs:complexContent>
<xs:extension base=“xaml:ParentControlType”>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“LabelType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“TextAlignment” type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“TextBoxType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“TextAlignment” type=“xs:string” use=“optional” />
<xs:attribute name=“MaxLength” type=“xs:string” use=“optional” />
<xs:attribute name=“MinLines” type=“xs:string” use=“optional” />
<xs:attribute name=“Wrap” type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“ButtonType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“TextAlignment” type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“LinkLabelType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“TextAlignment” type=“xs:string” use=“optional” />
<xs:attribute name=“LinkBehavior” type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“ImageType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“Source” type=“xs:string” use=“required” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“CheckBoxType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“TextAlignment” type=“xs:string” use=“optional” />
<xs:attribute name=“IsChecked” type=“xs:string” use=“optional” /
<!-- Events -->
<xs:attribute name=“IsCheckedChanged” type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- List Control Type -->
<xs:complexType name=“ListControlType”>
<xs:complexContent>
<xs:extension base=“xaml:ControlType”>
<xs:attribute name=“DisplayMemberPath” type=“xs:string” use=“optional” />
<xs:attribute name=“SelectedValuePath” type=“xs:string” use=“optional” />
<xs:attribute name=“SelectedValue” type=“xs:string” use=“optional” />
<xs:attribute name=“ItemsSource” type=“xs:string” use=“optional” />
<xs:attribute name=“SelectedIndex” type=“xs:string” use=“optional” />
<!-- Events -->
<xs:attribute name=“SelectionChanged” type=“xs:string” use=“optional” />
<!--
<xs:sequence>
<xs:element ref=“xaml:ListControlItem”
minOccurs=“0” maxOccurs=“unbounded” />
</xs:sequence>
-->
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- <xs:element name=“ListControl” type=“xaml:ListControlType”
abstract=“true” /> -->
<xs:simpleType name=“ListControlItemType”>
<xs:restriction base=“xs:string”>
</xs:restriction>
</xs:simpleType>
<xs:element name=“ListControlItem” type=“xaml:ListControlItemType”
abstract=“true” />
<xs:element name=“ListBoxItem” type=“xaml:ListControlItemType”
substitutionGroup=“xaml:ListControlItem” />
<xs:element name=“ComboBoxItem” type=“xaml:ListControlItemType”
substitutionGroup=“xaml:ListControlItem” />
<xs:element name=“RadioButton” type=“xaml:ListControlItemType”
substitutionGroup=“xaml:ListControlItem” />
<xs:complexType name=“ListBoxType”>
<xs:complexContent>
<xs:extension base=“xaml:ListControlType”>
<xs:sequence>
<xs:element ref=“xaml:ListBoxItem”
minOccurs=“0” maxOccurs=“unbounded” />
</xs:sequence>
<xs:attribute name=“SelectionMode” type=“xs:string”
use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“ComboBoxType”>
<xs:complexContent>
<xs:extension base=“xaml:ListControlType”>
<xs:sequence>
<xs:element ref=“xaml:ComboBoxItem”
minOccurs=“0” maxOccurs=“unbounded” />
</xs:sequence>
<xs:attribute name=“DropDownStyle”
type=“xs:string” use=“optional” />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name=“RadioButtonListType”>
<xs:complexContent>
<xs:extension base=“xaml:ListControlType”>
<xs:sequence>
<xs:element ref=“xaml:RadioButton”
minOccurs=“0” maxOccurs=“unbounded” />
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- UI Elements -->
<xs:element name=“Control” type=“xaml:ControlType” abstract=“true” />
<xs:element name=“Page” type=“xaml:PageType”
substitutionGroup=“xaml:Control” />
<xs:element name=“ObjectDataSource” type=“xaml:ObjectDataSourceType” />
<xs:element name=“XmlDataSource” type=“xaml:XmlDataSourceType” />
<xs:element name=“Panel” type=“xaml:PanelType”
substitutionGroup=“xaml:Control” />
<xs:element name=“ListBox” type=“xaml:ListBoxType”
substitutionGroup=“xaml:Control” />
<xs:element name=“ComboBox” type=“xaml:ComboBoxType”
substitutionGroup=“xaml:Control” />
<xs:element name=“RadioButtonList” type=“xaml:RadioButtonListType”
substitutionGroup=“xaml:Control” />
<xs:element name=“Label” type=“xaml:LabelType”
substitutionGroup=“xaml:Control” />
<xs:element name=“TextBox” type=“xaml:TextBoxType”
substitutionGroup=“xaml:Control” />
<xs:element name=“Button” type=“xaml:ButtonType”
substitutionGroup=“xaml:Control” />
<xs:element name=“CheckBox” type=“xaml:CheckBoxType”
substitutionGroup=“xaml:Control” />
<xs:element name=“Image” type=“xaml:ImageType”
substitutionGroup=“xaml:Control” />
<xs:element name=“LinkLabel” type=“xaml:LinkLabelType”
substitutionGroup=“xaml:Control” />
<!-- Control attributes -->
<!-- Since all attribute values could actually be binding expressions therefore the
type for each attributeis xs:string -->
<xs:attributeGroup name=“ControlTypeAttributes”>
<!-- Properties -->
<!-- Top and Left can be made required attributes but it's ok to
have them as optional -->
<xs:attribute name=“Top” type=“xs:string” default=“0” use=“optional” />
<xs:attribute name=“Left” type=“xs:string” default=“0” use=“optional” />
<xs:attribute name=“Width” type=“xs:string” use=“optional” />
<xs:attribute name=“Height” type=“xs:string” use=“optional” />
<xs:attribute name=“Anchor” type=“xs:string” use=“optional” />
<!-- Here we could have specfied an enumeration of Anchor values
but since this could also be a binding expression we have to leave it as a simple
string -->
<xs:attribute name=“Background” type=“xs:string” use=“optional” />
<xs:attribute name=“Foreground” type=“xs:string” use=“optional” />
<xs:attribute name=“FontFamily” type=“xs:string” use=“optional” />
<xs:attribute name=“FontSize” type=“xs:string” use=“optional” />
<xs:attribute name=“FontStyle” type=“xs:string” use=“optional” />
<xs:attribute name=“Name” type=“xs:string” use=“required” />
<xs:attribute name=“Tag” type=“xs:string” use=“optional” />
<xs:attribute name=“TabIndex” type=“xs:string” use=“optional” />
<xs:attribute name=“IsEnabled” type=“xs:string” use=“optional” />
<xs:attribute name=“Visibility” type=“xs:string” use=“optional” />
<xs:attribute name=“ToolTip” type=“xs:string” use=“optional” />
<xs:attribute name=“Text” type=“xs:string” use=“optional” />
<!-- Events -->
<xs:attribute name=“Click” type=“xs:string” use=“optional” />
<xs:attribute name=“GotFocus” type=“xs:string” use=“optional” />
<xs:attribute name=“LostFocus” type=“xs:string” use=“optional” />
<xs:attribute name=“KeyUp” type=“xs:string” use=“optional” />
<xs:attribute name=“KeyDown” type=“xs:string” use=“optional” />
<xs:attribute name=“MouseUp” type=“xs:string” use=“optional” />
<xs:attribute name=“MouseDown” type=“xs:string” use=“optional”
/>
<xs:attribute name=“TextChanged” type=“xs:string” use=“optional”/>
</xs:attributeGroup>
</xs:schema>
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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Metadata is used to create customized user interface (UI) portions for an application. The metadata may be XML-based and can be interpreted and then rendered to implement a customized UI that also supports data binding between data and the UI controls. Once created, the metadata is processed by a rendering engine to display the UI controls. An interpreter may be used to interpret the metadata file before it is sent to the rendering engine. Neither the rendering engine nor the interpreter needs knowledge of the host application and provides support for arbitrary metadata driven UI. The metadata schema may include mechanisms to create custom controls for the UI; programmatically modify the UI controls by providing access to a code-behind assembly as well as support event handling for the UI controls.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a 35 USC 371 application of PCT/EP2008/055522 filed on May 6, 2008.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an injector for a fuel injection system of an internal combustion engine, in particular in a motor vehicle.
2. Description of the Prior Art
In order to be able to further reduce pollutant emissions of internal combustion engines, further development has been primarily focused on increasing the injection pressure. In this connection, a large fuel volume in the injector body is advantageously sought in order to be able to keep pressure pulsations in multiple injections to a minimum. A reduction in hydraulic pulsations also has a favorable effect with regard to wear on the nozzle seat. The increase in the injection pressure in known injectors is usually achieved through execution of a pressure boosting, which is used to act on the fuel with a pressure that is greater than the pressure of the system, i.e. is acted on with a multiple of the atmospheric pressure, and at this high pressure, is metered into the combustion chamber. A supply of fuel to the pressure booster in this case is usually carried out via a plurality of interconnected bores, but these weaken the injector body, thus negatively affecting its service life, and are also susceptible to leaks.
ADVANTAGES AND SUMMARY OF THE INVENTION
The injector according to the invention has the advantage over the prior art that no bores for a hydraulic connection of a pressure boosting arrangement have to be provided in the injector body, thus making it possible to prolong the service life of the injector according to the invention. As in a conventional design, the injector according to the invention has a pressure boosting section, also referred to as the actuator section, and a needle section, the latter of which accommodates a nozzle needle that is able to execute a stroke motion in order to control an injection of fuel through at least one injection orifice. The pressure booster used to increase the fuel injection pressure has a stepped piston, a control rod, and a pressure booster bottom that cooperate with one another to delimit a coupler chamber. In lieu of bores in the injector body, in the injector according to the invention, a coupling path extending in the control rod is provided, which connects the coupler chamber to a high-pressure fuel supply via a valve device situated outside the injector. The essential advantage therefore lies in the simple central connection of the fuel supply to the pressure booster. This makes it possible to implement a relatively high injection pressure with a simultaneously moderate system pressure. In particular, the injector according to the invention also has a significantly improved multiple injection capacity because of its large high-pressure injector volume and reduced pressure pulsations thanks to its lack of control lines. Furthermore, it is also possible to achieve a rapid switching or actuation of the nozzle needle. The fact that it is possible to eliminate complex bores inside the injector body, which negatively affect the service life of the injector and are leakage-prone, significantly prolongs the service life of the injector according the invention.
The end of the control rod oriented toward the nozzle needle suitably reaches into a cavity provided in the pressure booster bottom; this cavity is hydraulically connected via a connecting path to a needle control chamber that is in turn delimited by the nozzle needle, a nozzle needle sleeve encompassing the needle, and the pressure booster bottom. The connecting path passing axially through the pressure booster piston, which can be embodied in the form of a bore for example, is situated centrally in comparison to conventional bores situated in the injector body and is therefore significantly easier to manufacture and seal. In particular, this design makes it possible to eliminate a hydraulic line routing in an injector body wall or outside the injector, leading to the needle control chamber, which constitutes a structurally simple and well-engineered embodiment.
In an advantageous embodiment of the design according to the invention, the stepped piston is encompassed by a filling sleeve that is able to execute a stroke motion on it or by a stationary annular wall; the stepped piston, the pressure booster bottom, and the filling sleeve or stationary annular wall cooperate with one another to delimit a pressure booster chamber, commonly also referred to as an intensifier chamber. In the embodiment with a filling sleeve, which is supported so that it is able to execute a stroke motion on the stepped piston, it is also possible for a prestressing spring to be provided, one end of which rests against a stop on the injector body and the other end of which rests against the filling sleeve, prestressing the latter against the pressure booster bottom. The stepped piston, the pressure booster bottom, and the filling sleeve or annular wall, together with the prestressing spring provided in the case of the filling sleeve, form a boosting device for boosting the pressure prevailing in the coupler chamber to a significantly higher pressure required for the injection process in the pressure booster chamber. A boosting action is produced by the significant size differences between the coupler chamber and the pressure booster chamber. This makes it possible to achieve a high injection pressure with a simultaneously moderate system pressure, thus permitting reduction of the pollutant emissions of the internal combustion engine equipped with the injector according to the invention.
In another advantageous embodiment of the design according to the invention, the injector body is provided with a high-pressure chamber in which the control rod, the stepped piston, and the filling sleeve or annular wall are situated. The high-pressure chamber in this case is significantly larger in comparison to the coupler chamber, the pressure booster chamber, and the needle control chamber and has the greatest volume. A large-volumed high-pressure chamber has a positive effect on pressure pulsations in multiple injections, which can be kept to a minimum.
The high-pressure fuel supply is suitably connected directly to the high-pressure chamber via a hydraulic line and indirectly to the coupling path in the control rod via the valve device. In this case, both the direct supply to the high-pressure chamber and the indirect supply to the coupling path in the control rod via the valve device extend at least partially parallel to each other in an injector end plate so that a connection of the injector according to the invention to the high-pressure fuel supply is possible via only one side, namely the injector end plate. It is therefore unnecessary to provide an additional, structurally complex line routing, for example to the pressure booster chamber or needle control chamber.
Other important defining characteristics and advantages of the injector according to the invention ensue from the dependent claims, the drawings, and the associated description of the figures given in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the injector according to the invention are shown in the drawings and will be explained in detail in the subsequent description.
FIG. 1 is a very simplified schematic longitudinal section through an injector according to the invention,
FIG. 2 is a schematic depiction like the one in FIG. 1 , but of a different embodiment,
FIG. 3 is also a schematic depiction like the one in FIG. 1 , but of a different embodiment, and
FIG. 4 is a very simplified schematic longitudinal section through another embodiment of the injector according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to FIGS. 1 through 4 , the injector 1 according to the invention includes an injector body 2 , which is usually composed of two sections, namely a needle section 3 situated at the bottom and a pressure booster section 4 situated above the former. The two sections 3 and 4 can be attached to each other by a suitable connecting technique, for example a welded connection or a screw connection. In the exemplary embodiments shown, a clamping nut 5 is provided, which encompasses the needle section 3 and clamps it against the pressure booster section 4 . The clamping nut 5 is preferably screwed onto the pressure booster section 4 .
The injector 1 is supplied by a high-pressure fuel supply 6 , which is connected directly to a high-pressure chamber 8 situated in the injector 1 via a hydraulic line 7 and is connected indirectly to a coupling path 11 situated in a control rod 10 via a hydraulic line 7 ′ equipped with a valve device 9 .
The needle section 3 is provided with at least one injection orifice 12 and a nozzle needle 13 supported so that it is able to execute a stroke motion in order to control an injection of fuel through the at least one injection orifice 12 . At an end oriented away from the at least one injection orifice 12 , the nozzle needle 13 has a nozzle needle sleeve 14 encompassing it, which is prestressed against a pressure booster bottom 16 by a closing compression spring 15 , one end of which rests against the nozzle needle sleeve 14 and the other end of which rests against the nozzle needle 13 or against a stop situated there. At the same time, the closing compression spring 15 prestresses the nozzle needle 13 into its closed position. The nozzle needle 13 is situated so that it is able to execute a stroke motion in a nozzle chamber 28 , which is hydraulically connected to a pressure booster chamber 27 via at least one through opening 29 provided in the pressure booster bottom 16 . The pressure booster section 4 contains a pressure booster 17 for increasing a fuel injection pressure in relation to a system pressure. The pressure booster 17 has a stepped piston 18 , the control rod 10 , and the pressure booster bottom 16 , which cooperate with one another to delimit a coupler chamber 19 . According to the invention, the coupling path 11 extends inside the control rod 10 and connects the coupler chamber 19 to the high-pressure fuel supply 6 via the valve device 9 situated outside the injector 1 . The valve device 9 here can for example be embodied in the form of a solenoid valve or a piezoelectric actuator or also in the form of a 2/2-way or 3/2-way solenoid valve or piezoelectric valve that has a 3/2-way functionality in combination with a servo valve.
With its end oriented toward the nozzle needle 13 , the control rod 10 reaches into a cavity 20 provided in the pressure booster bottom 16 , which cavity is hydraulically connected to a needle control chamber 22 via a connecting path 21 . The needle control chamber 22 here is delimited by the nozzle needle 13 , the nozzle needle sleeve 14 encompassing the latter, and the pressure booster bottom 16 . At the same time, the cavity 20 is connected to the coupler chamber 19 via the coupling path 11 ; the coupling path 11 has radial openings 23 in the region of the coupler chamber 19 . As is shown in FIGS. 2 through 4 , it is possible for the cavity 20 to contain a control rod spring 24 , which prestresses the control rod 10 in the direction oriented out from the cavity 20 , i.e. upward. In the pressure booster bottom 16 , a connecting line 30 is also provided, which is embodied for example in the form of a bore and hydraulically connects the pressure booster chamber 27 to the needle control chamber 22 . The connecting line 30 and/or the connecting path 21 can optionally be provided with a throttle device 31 ; for example, the throttle device 31 in the connecting path 21 can be embodied in the form of an outlet throttle and the throttle device 31 in the connecting line 30 can be embodied in the form of an inlet throttle.
According to FIGS. 1 through 3 , the stepped piston 18 of the pressure booster 17 is encompassed by a filling sleeve 25 that is supported so that it is able to execute a stroke motion on the stepped piston 18 . According to FIG. 4 , the stepped piston 18 is encompassed by a stationary annular wall 26 . The annular wall 26 in this case can be embodied as separate from or of one piece with the pressure booster bottom 16 . The stepped piston 18 , the pressure booster bottom 16 , and a filling sleeve 25 or stationary annular wall 26 cooperate with one another to delimit a pressure booster chamber 27 .
According to FIGS. 1 , 2 , and 4 , a stepped piston spring 32 is provided, one end of which rests against a stop 33 on the injector body or collar 38 ( FIG. 4 ) and the other end of which rests against the stepped piston 18 . According to FIGS. 1 and 2 , the stepped piston spring 32 presses the stepped piston 18 upward, thus clamping it in a nonoperating state against a stop 33 ′, which is embodied as an annular external step on the control rod 10 . At the same time, this presses the control rod 10 against an end plate 34 , thus sealing the coupling path 11 in relation to the high-pressure chamber 8 .
The stop 33 on the injector body is provided with at least one axial through opening 35 , which hydraulically connects the high-pressure chamber 8 to its section 8 ′ ( FIG. 1 ) situated below the stop 33 .
According to FIGS. 1 and 2 , a prestressing spring 36 , which prestresses the filling sleeve 25 against the pressure booster bottom 16 , rests against a side of the stop 33 oriented away from the stepped piston spring 32 . In the embodiment according to FIG. 3 , the prestressing spring 36 is embodied in the form of a clamping spring, one end of which rests against the stepped piston 18 and the other end of which rests against the filling sleeve 25 , prestressing the latter against the pressure booster bottom 16 .
In the embodiment of the injector 1 according to FIG. 2 , the stepped piston 18 is embodied in the form of a so-called “free-flying piston,” which has no stroke stop on the control rod 10 . As in FIGS. 3 and 4 , the control rod spring 24 here clamps and seals the control rod 10 against the end plate 34 . The advantage here is that rapid pressure changes are compensated for directly by means of stroke changes of the stepped piston 18 , thus making it possible to assure that the injector 1 does not open unintentionally, particularly in the event of a rapid decrease in system pressure.
The depiction in FIG. 3 shows a variant in which the filling and resetting of the pressure booster 17 is assured not by an opening of the filling sleeve 25 , but by a modified nozzle needle sleeve 14 . In this case, a sealing edge of the nozzle needle sleeve 14 is situated radially toward the outside in comparison to the embodiments of the injector 1 according to FIGS. 1 and 2 . A sealing diameter of the nozzle needle sleeve 14 therefore lies on a larger diameter, which achieves an opening when a pressure in the needle control chamber 22 is greater than in the nozzle chamber 28 .
In the variant according to FIG. 4 , a stepped piston resetting by means of the stepped piston spring 32 has also been redesigned to make it possible to achieve an advantage in terms of space. For this reason, the stepped piston spring 32 rests against the injector body 2 via an annular collar 38 and presses against the stepped piston 18 via a washer 39 in order to reset the stepped piston after the end of the injection process.
The function of the injector 1 according to the invention can be described as follows:
First, all of the volumes of the injector 1 are at the system pressure level. If the pressure in the coupling path 11 is reduced through actuation of the valve device 9 , then the pressure in the needle control chamber 22 and the pressure in the coupler chamber 19 decrease. On one hand, this causes an increase in the forces acting in the opening direction on the nozzle needle 13 , causing it to open. On the other hand, a pressure increase occurs in the pressure booster chamber 27 as a result of a pressure decrease in the coupler chamber 19 . Consequently, the pressure in the nozzle chamber 28 also increases and the injector 1 injects fuel into a combustion chamber at an injection pressure that is higher than the system pressure.
In order to close the injector 1 , the valve device 9 is actuated, in particular closed, causing the pressures in the needle control chamber 22 and in the coupler chamber 19 to rise to system pressure again. If the pressures have returned to the system pressure level, then the stepped piston spring 32 produces a slight negative pressure in the pressure booster chamber 27 , causing the filling sleeve 25 to open and the resetting of the stepped piston 18 in combination with a volume compensation, causes a resetting of the injector 1 into its initial position.
One particular advantage of the injector 1 according to the invention is the central location of the coupling path 11 inside the control rod 10 , which permits the elimination of high-pressure bores in the injector body 2 . This makes it possible to achieve a high injection pressure with a simultaneously moderate system pressure by means of only a single valve device 9 . At the same time, it is possible to achieve a rapid switching of the nozzle needle 13 and a significantly improved multiple injection capacity due to a large volume of the high-pressure chamber 8 and reduced pressure pulsations through the elimination of control lines.
The foregoing relates to the preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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The invention relates to an injector for a fuel injection system of an internal combustion engine, particularly in a motor vehicle, with an injector body which has a pressure booster section and a needle section. At least one injection hole is provided in the needle section. A nozzle needle which has an adjustable stroke is disposed in the needle section for controlling an injection of fuel through the at least one injection hole. A pressure booster is provided for increasing a fuel injection pressure relative to a system pressure. For this purpose, the pressure booster has a double-diameter or stepped piston, a control rod, and a pressure booster bottom which together form the boundary of a coupling chamber. A coupling path extends into the control rod and connects the coupling chamber, over a valve device which is located outside or within the injector, to a high-pressure supply of fuel.
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FIELD OF THE INVENTION
This invention relates generally to a process for imparting biocidal properties to textiles and fabric, and, more specifically, to a process employing pyrithione salts in treating clothes and other fabrics during the dryer cycle in order to impart biocidal activity thereto.
BACKGROUND OF THE INVENTION
Pyrithione acid (1-hydroxy-2-pyridinethione) and various salts thereof are well-known biocides exhibiting broad spectrum anti-bacterial and anti-fungal activity. Illustrative applications are disclosed, for example, in U.S. Pat. No. 4,818,436 which discloses the use of pyrithiones in metal working fluids, and U.S. Pat. No. 4,935,061 which discloses their use in paints. Zinc pyrithione is widely used in hair care products such as shampoos.
The use of fabric treating articles and processes in clothes driers is also well-known in the art. For example, U.S. Pat. No. 4,073,996 discloses the use of various flexible substrate articles in clothes driers during the clothes-drying cycle in order to impart desired characteristics to the clothing being dried. Also, the '996 patent discloses the direct addition of desired additives from a spray device (e.g., an aerosol can, mechanical spray pump, or the like) using a carrier such as a propellant and/or solvent, alone or in the presence of other optional additives, such as finishing aids, fumigants, lubricants, fungicides, and sizing agents (see column 8, lines 34-35 of the '996 patent). However, no specific biocides are disclosed in this patent.
British Pat. No. 1,390,004 has shown that the addition of zinc pyrithione, in an aqueous solution of a quaternary ammonium compound during the rinse cycle of a laundering operation, results in a high degree of anti-microbial activity. However, this methodology is more expensive than might be desired since significant amounts of the zinc pyrithione are carried away with the rinsate during the rinse cycle.
U.S. Pat. No. 4,443,222 discloses the application of zinc pyrithione to cellulosic textiles by first solubilizing the zinc pyrithione in a polyamine and urea, and then impregnating the cellulosic textile with the resulting solution, and then heating the clothing to cause a specific reaction with the impregnating chemicals. This patent claims the resulting anti-microbial activity is durable to laundering. However, due to its complexity, this is not a method which lends itself to home use by a consumer on an as-needed basis.
Heretofore, there has been no disclosure in the prior art to the knowledge of the present inventors of the use of pyrithione acid, or salts thereof, as a drier-cycle additive to provide biocidal efficacy for clothing.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a method for imparting biocidal protection to clothing or other fabrics which comprises contacting the clothing or other fabrics with a biocidally effective amount of pyrithione acid, or salt(s) thereof, or combinations thereof, in an automatic laundry dryer.
In another aspect, the present invention relates to a transfer substrate containing a biocide consisting essentially of pyrithione acid, or salt(s) thereof, or combinations thereof, said biocide being present in or on said transfer substrate in an amount sufficient to impart antimicrobial activity to clothing or other fabric in an automatic clothes dryer.
These and other aspects will become apparent upon reading the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The pyrithione employed in the present invention is preferably selected from the group consisting of pyrithione acid, sodium pyrithione, zinc pyrithione, copper pyrithione, aluminum pyrithione, magnesium pyrithione, pyrithione disulfide, 2,2'-dithiobis-pyridine-1,1'-dioxide, chitosan pyrithione, and combinations thereof. Particularly preferred pyrithione salts useful in the present invention include sodium pyrithione, zinc pyrithione, pyrithione disulfide, and chitosan pyrithione.
The sodium pyrithione suitably employed in the process of the present invention is a well known commercial product and is commonly made by reacting 2-chloropyridine-N-oxide with NaSH and NaOH, as disclosed in U.S. Pat. No. 3,159,640, the disclosure of which is incorporated herein by reference in its entirety.
Zinc pyrithione is produced by reacting 1-hydroxy-2-pyridinethione or a soluble salt thereof with a zinc salt (eg.,ZnSO 4 ) to form a zinc pyrithione precipitate, as disclosed in U.S. Pat. No. 2,809,971, incorporated herein by reference. Zinc and sodium pyrithione, as well as pyrithione disulfide and pyrithione magnesium disulfide, are commercially available under Olin Corporation's OMADINE® registered trademark.
Chitosan pyrithione is another well-known biocide that is suitably produced in accordance with the process disclosed in U.S. Pat. No. 4,957,908, incorporated herein by reference in its entirety. Typical methods of preparing chitosan pyrithione include either reacting chitosan acetate with a pyrithione salt such as sodium pyrithione, or by neutralization of chitosan, which is a weak base, with a pyrithione acid.
The process of the present invention employs pyrithione acid, or a salt thereof, or a combination thereof to impart anti-microbial activity to fabric or textiles. The pyrithione is applied to the clothes or other fabric in the dryer, before or during the normal dryer cycle, in order to impart antimicrobial activity to the clothes or other fabric during laundering. This is accomplished by applying the pyrithione either directly using gravity or pressurized feed or aerosol spray, or indirectly using an appropriate transfer mechanism such as a transfer substrate, such as a sheet, pillow, or other substrate utilized to transfer the biocide to the clothes or other fabric during the drying cycle in the dryer. The transfer vehicle is used to transfer sufficient quantities of the pyrithione to the clothes or other fabric to impart antimicrobial activity thereto. Typically, the pyrithione is employed in the dryer in an amount sufficient to impart at least about 0.1 gram of pyrithione per laundry load in the dryer. An amount of between about 5 and about 5,000 ppm, preferably between about 5 and about 40 ppm, more preferably between about 5 and about 30 ppm, of pyrithione, based upon the weight of the clothes or other fabric being dried, is suitably imparted to the clothes or other fabric during the drying cycle in the dryer. If the transfer vehicle is a nonwoven sheet, such as a rayon sheet, the amount of pyrithione employed is between about 0.05 and about 10 grams per square foot of the said nonwoven sheet. The broad range of amounts (i e., between about 5 and about 5,000 ppm) is sufficient to impart antimicrobial activity to the clothing which inhibits the growth of unwanted microbes, including yeast, odor- and disease-causing bacteria, fungus, mildew, and the like, on the clothing or other fabric during use thereof.
Thus, fabric and textiles treated by this process exhibit growth inhibition with respect to gram (+) and gram (-) bacteria, yeast and fungi, including pathogenic organisms which are of particular concern in hospital environments.
While the invention has been described above with references to specific embodiments thereof, it is apparent that many changes, modifications and variations in the materials, arrangements of parts and steps can be made without departing from the inventive concept disclosed herein. Accordingly, the spirit and broad scope of the appended claims is intended to embrace all such changes, modifications and variations that may occur to one of skill in the art upon a reading of the disclosure. All patent applications, patents and other publications cited herein are incorporated by reference in their entirety.
EXAMPLE I
Use of Zinc Pyrithione Dispersion on a Dryer-Cycle Sheet to Impart Biocidal Efficacy to Clothes Being Dried
A 48% aqueous dispersion of zinc pyrithione, commercially available as zinc OMADINE®, a product of Olin Corporation, was diluted to 10.6% active ingredient using water. A nonwoven rayon sheet was then soaked in the said 10.6% dispersion and allowed to soak for 10 minutes. The saturated sheet was then dried for 10 minutes at 60° C. and weighed. The resultant dry weight of the zinc OMADINE and the nonwoven rayon sheet was approximately 80% of the said pyrithione. Both cotton and cotton/polyester (65/45) swatches of fabric were wet with standard tap water and wrung out to remove excess water. These were then charged to a standard household dryer with a zinc OMADINE treated nonwoven rayon sheet and dried for 30 minutes. Weight differences of foresaid swatches before and after dryer cycle were not apparent on available weighing balance, which attests to the small amount of the zinc pyrithione necessary to impart antimicrobial protection.
A Zone of Inhibition test was performed on the resulting swatches. This test measures the zone of no microbial growth surrounding a sample. An untreated sample should not produce a zone where microbial growth is inhibited. Zones were measured using Candida albicans --yeast, Aspergillus niger --mold, Staphylococcus aureus --gram (+) bacteria, and Klebsiella pneumoniae --gram (-) bacteria. Bacteria strains used in this test are recommended test organisms in the AOAC method "Bacteriostatic Activity of Laundry Additive Disinfectants".
All samples dried with the zinc pyrithione treated nonwoven rayon sheet demonstrated pronounced zones of inhibition. All samples dried with an untreated nonwoven sheet showed no signs of a zone of inhibition.
EXAMPLE II
Use of Sodium Pyrithione Dispersion on Dryer-Cycle Sheet to Impart Biocidal Efficacy to Clothes Being Dried
A 40% aqueous solution of sodium pyrithione, commercially available as sodium OMADINE®, a product of Olin Corporation was used for this procedure. A nonwoven rayon sheet was then soaked in the said 40% solution and allowed to soak for 10 minutes. The saturated sheet was then dried for 10 minutes at 60° C. and weighed. The resultant dry weight of the sodium OMADINE and the nonwoven rayon sheet was approximately 80% of the said pyrithione. Both cotton and cotton/polyester (65/45) swatches of fabric were wet with standard tap water and wrung out to remove excess water. These were then charged to a standard household dryer with a sodium OMADINE treated nonwoven rayon sheet and dried for 30 minutes. Weight differences of foresaid swatches before and after dryer cycle were not apparent on available weighing balance, which attests to the small amount of the sodium pyrithione necessary to impart antimicrobial protection.
A Zone of Inhibition test was performed on the resulting swatches. This test measures the zone of no microbial growth surrounding a sample. An untreated sample should not produce a zone where microbial growth is inhibited. Zones were measured using Candida albicans--yeast, Aspergillus niger--mold, StaPhylococcus aureus--gram (+) bacteria, and Klebsiella pneumoniae--gram (-) bacteria. Bacteria strains used in this test are recommended test organisms in the AOAC method "Bacteriostatic Activity of Laundry Additive Disinfectants".
All samples dried with the sodium pyrithione treated nonwoven rayon sheet demonstrated pronounced zones of inhibition. All samples dried with an untreated nonwoven sheet showed no signs of a zone of inhibition.
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The present invention relates to a method for imparting biocidal protection to clothing or other fabrics which comprises contacting the clothing or other fabrics with a biocidally effective amount of pyrithione acid, or salt(s) thereof, or combinations thereof, in an automatic laundry dryer. Also disclosed is a transfer substrate containing a biocide consisting essentially of pyrithione acid, or salt(s) thereof, or combinations thereof, said biocide being present in or on said transfer substrate in an amount sufficient to impart antimicrobial activity to clothing or other fabric in an automatic clothes dryer.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional patent application Ser. No. 60/073,207, filed Jan. 30, 1998.
FIELD OF THE INVENTION
The invention relates to Mannich bases of conjugated styryl ketones, having antineoplastic and antifungal bioactivity.
BACKGROUND OF THE INVENTION
There has been a need for new anticancer and antifungal compounds. It has been previously determined that a number of 5-amino-1-aryl-1-penten-3-one hydrohalides and related compounds possess significant cytotoxic and anticancer properties. These previously synthesized compounds were developed as thiol alkylators since unsaturated ketones have a marked affinity for thiols in contrast to amino and hydroxy groups. Hence, interactions with nucleic acids may be avoided and the disadvantages of certain alkylating agents such as mutagenicity and carcinogenicity may be absent. Support for the contention that these compounds have a different mode of action than such widely used alkylating agents as melphalan was provided by noting their displaying similar cytotoxicity towards melphalan-resistant and melphalan-sensitive neoplastic cells i.e. the melphalan-resistant cell lines were free from cross resistance to these Mannich bases. In addition, several series of Mannich bases have been prepared recently which were designed using the concept of sequential cytoxicity. This theory may be defined as the successive release of two or more cytotoxic agents whereby greater toxicity to malignant rather than normal cells will be displayed.
As a mechanism for cell death, apoptosis plays an important role in the regulation of normal and cancer cells. The characteristic features of apoptosis which distinguish it from necrosis are cell shrinkage, cytoplasimic blebbing, loss of membrane architecture, chromatin condensation, fragmentation of DNA into oligonucleoside-sized fragments (180-200 bp in length) and formation of apoptotic bodies. Endogenous cleavage of the DNA is believed to be carried out by an endogenous Ca 2+ /Mg 2+ dependent endonuclease that can be inhibited by the addition of Zn 2+ . Inhibitors of messenger RNA and protein synthesis in many cases have been reported to suppress apoptosis. Apoptosis is considered to be the major mechanism by which antineoplastic drugs mediate their cytotoxic effects. Moreover tumor sensitivity and resistance to drugs has also been linked, at least in part, to inactivation of a genetic program for cell death. Induction of apoptosis in cancerous cells may therefore be an effective approach for the treatment of cancer. It is an object of this invention to provide a compound capable of inducing apoptosis in cancerous cells.
As indicated above, there is also a need for novel antifungal agents with different chemical structures and targets of action from the drugs used today. In this manner, new therapies can evolve which not only exert significant antifungal properties but can be employed in cases where drug resistance has emerged.
Recently, Mannich bases of a series of acyclic conjugated styryl ketones were synthesized which possessed minimum inhibitory concentrations (MICs) in the 0.1-1.5 mM range against pathogenic yeasts, in particular Candida albicans. However, the potencies of these novel compounds towards C. albicans were approximately 2-3 orders of magnitude lower than that of the established antifungal drugs such as fluconazole and amphotericin B which had mean MIC values of approximately 0.8 μm and 0.6 μm, respectively. Since the compounds previously studied contained only one center for nucleophilic attack by cellular thiols, there has been a need for a series of new conjugated styryl ketones which possessed an additional site at which thiol-alkylation could occur wherein the chemical reactivity of the two centres for nucleophilic attack would be predicted to be different and alkylation of cellular thiols would proceed in a stepwise fashion. Thus it is a further object of the invention to provide antifungal compounds of increased potencies.
SUMMARY OF THE INVENTION
In accordance with the invention, compounds of the general formula A-X-B-Y-A (Compound I) or A-X-B-A (Compound II) are provided wherein A is: ##STR2## and R 1 , R 2 and R 3 are independently selected from hydrogen, halogen, lower alkyl, methoxy and hydroxy;
X is selected from: ##STR3##
B is selected from any one of ##STR4## where the salt may be a salt of tertiary or quaternary amine, and Y is ##STR5##
The invention relates more particularly to compounds of the formula: ##STR6## wherein R 1 and R 2 are selected from the group consisting of hydrogen, halogen, lower alkyl and lower alkoxy. Preferably, R 1 is Cl, CH 3 or OCH 3 and R 2 is H or Cl.
A compound of special interest according to the invention is (3-[3-(4-chlorophenyl)-2-propenoyl]-4-[2-(4-chlorophenyl)vinylene]-1-ethyl-4-piperidinol hydrochloride.
The invention also provides a method of treating a fungal infection in an organism comprising administering a pharmaceutically acceptable amount of any of the above compounds to the organism.
Still further, the invention provides a method of inducing apoptosis in cancer cells by administering a pharmaceutically acceptable amount of any of the above compounds to the cancer cells.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will be more apparent from the following description in which reference is made to the appended drawings wherein:
FIG. 1A is a flow chart of the synthesis of compounds 1a-e, 2a-e, 3a-e, 9a-e and 10a,c,d in accordance with the invention;
FIG. 1B is a flow chart of the synthesis of compounds 4a-e, 5a-f, 6a-e, 11a-f and 12a-e in accordance with the invention,
FIG. 2 is a graph showing a comparison of fungicidal activities of compound 9b, amphotericin B and itraconazole against Aspergillus fumigatus;
FIG. 3 is a graph showing in vivo susceptibility of Aspergillus fumigatus to Compound 9b in a murine pulmonary asperigillosis model showing the percent survival of animals treated with AMB or Compound 9b;
FIG. 4 is a graph showing in vivo susceptibility of Aspergillus fumigatus to Compound 9b in a murine pulmonary asperigillosis model showing the effect of therapy on the fungal load (CFU/lungs) of infected animals;
FIG. 5 is a graph showing percent viability of Jurkat T, LV-50, H-9 and Molt 3 cells after exposure to 10 μM of compound 9d for a 24 hour period with error bars representing mean±standard deviation in three separate experiments;
FIG. 6 is a graph of the percent growth inhibition of human Jurkat T cells after exposure to increasing concentrations of Compound 9d or melphalan wherein the IC 50 is the drug concentration that causes 50% growth inhibition and was determined by extrapolation from FIG. 5;
FIG. 7 is a fluorescence micrograph of human Jurkat T cells identifying the characteristic morphological features of untreated control cells (17 h culture) that have remained intact and exhibited intense fluorescence of the nuclei (magnification ×1000);
FIG. 8 is a fluorescence micrograph of human Jurkat T cells identifying the characteristic morphological features of Compound 9d treated (6 μM) cells (17 h culture) showing characteristic blebbing and apoptotic bodies as seen by the presence of condensed chromatin and decreased fluoresecence (magnification ×1000);
FIG. 9 is a graph of the apoptotic index (% apoptotic cells) versus time (h).
DETAILED DESCRIPTION OF THE INVENTION
For the sake of simplicity, the compounds referred to throughout the description are defined by numbers. The aryl substitution pattern for these compounds is set forth in Table 1.
TABLE 1______________________________________Aryl substitution Pattern Letter R.sub.1 R.sub.2______________________________________a H H b Cl H c Cl Cl d CH.sub.3 H e OCH.sub.3 H f OH H______________________________________
The compounds are as follows: ##STR7##
The compounds of series 1 were first prepared for cytotoxic evaluation. In addition, in order to evaluate the theory of sequential cytotoxicity the bis Mannich bases 2 were proposed. Initial thiol attack could occur at one of the olefinic double bonds to be followed by a second thiol interaction which could be more damaging to neoplastic cells than normal tissues. This assumption depends on nonequivalent charges in the bulky groups attached to the nitrogen atom vide infra. Since the rate of thiol attack will be increased when the nitrogen is in the quadrivalent or ionized form, the related quaternary ammonium compounds 3 should be more cytotoxic than compounds 2. The use of a null hypothesis suggested the preparation of compounds 4-6 which lacked olefinic double bonds as outlined in FIG. 1 B. These compounds were predicted to be less cytotoxic than the analogs 1-3. Alternatively, bioactivity displayed by these molecules, led to the conclusion that the structural features in compounds 1-3 other than the olefinic double bonds would probably contribute to bioactivity.
The aryl substitution pattern in 1-6 series of compounds, which has been employed in a Topliss analysis, was chosen so that atoms and groups with divergent electronic and hydrophobic properties were used. In fact, the chloro, methyl and methoxy substituents are found in three different quadrants of a two-dimensional Craig plot.
The electrostatic charges on certain of the atoms in the unsubstituted compounds in series 1-6 were compared as shown in the following formula and in Table 2. ##STR8##
The following observations were noted. First, variation in the charges on carbon atoms 1 and 5 in each of the bis compounds 2a and 5a meant that in each molecule, a different electronic effect will be exerted on the adjacent olefinic bond. Thus initial nucleophilic attack by a cellular constituent at one carbon atom would be followed by a subsequent thiol-alkylation as the theory of sequential cytotoxicity requires. Second, in addition to thiol-alkylation at the olefinic bonds, Mannich bases can react by amino group replacement by thiols at the 2 (and 4) atoms. This reaction may be an elimination-addition process or by nucleophilic attack. The rate determining step in an elimination reaction is the loss of the proton adjacent to the carbonyl group. Hence, if the elimination-addition mechanism operates at the cellular level, compounds 1-3 containing olefinic bonds should be more active than the analogs 4-6 since the negative charges on carbon atom 1 (and 5) are greater in compounds 1a, 2a and 3a and hence the proton is more acidic than in the analogs 4a, 5a and 6a. On the other hand, nucleophilic attack at carbon atom 2 (and 4) would be greater when the negative charge is lower. Hence in comparing the olefinic versus the non-olefinic analogs, the potency orders would be 1a>4a, 5a>2a and 3a>6a. Third, somewhat surprisingly, the nitrogen atoms in the Mannich bases 1a, 2a, 4a, and 5a but not the quaternary ammonium salts 3a and 6a bore negative charges. To a good approximation, the charges on the nitrogen atom can be replaced by one total charge in which case the combined charges of compounds 1a, 2a, 4a and 5a are positive. If the quadrivalent nitrogen atom interacted with an anionic group at a binding site, then the potency relationships would be as follows namely, 4a>1a, 2a>5a and 3a>6a.
TABLE 2______________________________________The electrostatic charges on certain atoms of 1a, 2a, 3a, 4a, 5a, and 6a Electrostatic charges of atoms.sup.aCompound C1 C2 C3 C4 C5 R6.sup.b______________________________________1a -0.296 0.017 -0.191 -- -- 0.332 2a -0.252 -0.151 -0.074 -0.173 -0.209 0.368 3a -0.28 -0.11 0.364 -0.184 -0.202 0.108 4a -0.112 -0.143 -0.112 -- -- 0.368 5a -0.136 -0.04 -0.163 -0.087 -0.107 0.382 6a 0.032 -0.192 0.269 -0.202 0.08 0.119______________________________________ .sup.a The designation of atoms is given in the above formula. .sup.b R=H (1a, 2a, 4a, 5a) or CH.sub.3 (3a, 6a).
Compound 7 (as the hydrobromide salt) was previously synthesized and shown as having 1.3 times the activity of 5-fluorouracil against the human WiDr colon cancer in vitro.
The preparation of compounds 8a,b was proposed in order to evaluate further the structural features contributing to cytotoxicity. Thus the pka values of the nitrogen atoms of piperazine are 5.33 and 9.73 while the figure for triethylamine is 10.75. Hence under biological conditions, compound 1a should have a higher percentage of molecules as the ionized species than compound 8a and thus display greater cytotoxicity. A comparison of the screening data of compounds 8a and 8b indicates the importance of olefinic bonds in this group of molecules.
EXAMPLE 1
Synthesis of Compounds
Compounds 1a-e, 7 and 8a were prepared from the appropriate arylidene methyl ketone, formaldehyde and secondary amine hydrochloride. The Mannich bases 4a-e and 8b were prepared in a similar fashion from the appropriate aryl methyl ketone. Attempts to prepare the quaternary ammonium salts from the tertiary amines 1 and 4 led to the isolation of impure products only; these synthetic difficulties have also been noted by other laboratories. However reaction of diethylamine hydrochloride with one mole excess of both arylidene methyl ketone or aryl methyl ketone and formaldehyde led to compounds 9 and 11 respectively. The significant in vitro and in vivo activity of compound 9d vide infra suggested the preparation of the analogs 13a,b which were synthesized by the same route. Reaction of the free bases of compounds 9a,c,d with methyl bromide gave rise to compounds 10a,c,d respectively while the quaternary ammonium salts 12 were prepared from the free bases of compound 11. The structures of the compounds were determined by 1 H NMR spectroscopy and elemental analyses.
Compounds 1a-e, 4a-e and 7 were obtained as acyclic molecules.
However, 1 H NMR spectroscopy revealed that the products obtained in the attempts to synthesize the compounds in series 2, 3, 5 and 6 were in fact the piperidines 9-12. Further support for the formation of these cyclized products was obtained as follows. First, X-ray crystallographic data of four representative compounds 10d, 12d, 13a and 13b confirmed that piperidines were formed and second a review of the literature revealed previous reports of this type of reaction. The piperidines were presumably synthesized as follows. Initially the bis Mannich bases 2 and 5 would be formed and abstraction of a proton from a methylene group adjacent to a carbonyl function would enable the resultant carbanion to undergo nucleophilic attack at the carbon atom of the second carbonyl group. Protonation of the negatively charged oxygen atom would lead to the compounds in series 9 and 11 which on quaternization would give rise to compounds 10 and 12 respectively. The piperazine analogs 8a,b did not undergo intramolecular cyclization. In these cases, a cyclization process would require the formation of a 9-membered ring system.
The following formula indicates three structural features of the compounds in series 9 which could contribute to cytotoxicity. ##STR9##
These piperidines are Mannich bases containing many of the structural features found in series 1 compounds as well as possessing an isolated β-arylethylenic group. In addition, loss of the allylic hydroxy group would give rise to a reactive carbonium ion stabilized by the presence of the adjacent β-arylethylenic group. These features should permit interaction with cellular thiols to occur which, if a major contributor to bioactivity, permits the following predictions pertaining to structure and cytotoxicity to be made namely: 1>4, 9>11 and 10a,c,d,>12a,c,d. If quaternization increases chemical reactivity of the olefinic centers, then 10a,c,d>9a,c,d. Furthermore reaction of thiols occurs at a far greater rate with Mannich bases of conjugated styryl ketones than the corresponding α,β-unsaturated ketones. Hence thiol alkylation should occur at carbon atom A much more rapidly than at B and the principle of sequential cytotoxicity should therefore be exemplified. Thus the compounds in series 9 should display more than twice the cytotoxicity of the analogs in series 1. In summary, series 9 and the related quaternary ammonium salts 10 should be potent cytotoxic agents based on their potential for thiol alkylation and sequential attack of cellular constituents.
EXAMPLE 2
Cytotoxic Properties
The cytotoxic properties of the compounds in series 1, 4 and 7-13 as well as the established anticancer drug melphalan are portrayed in Table 3. In order to detect compounds with selective toxicity towards neoplastic tissues in contrast to normal cells, many of the Mannich bases and analogs were evaluated against Molt 4/C8 and CEM human T-lymphocytes.
TABLE 3__________________________________________________________________________Cytotoxicity data of various Mannich bases and related compounds. P388 L1210 human cells cells tumors IC.sub.50 IC.sub.50 IC.sub.50 Molt 4/C8 cells CEM cellscompd.sup.a (μM) (μM) (μM) IC.sub.50 (μM) TI.sub.P388.sup.b TI.sub.L1210.sup.b TI.sub.ht.sup.b IC.sub.50 (μM) TI.sub.P388.sup.b TI.sub.L1210.sup.b TI.sub.ht.sup.b__________________________________________________________________________1a 1.7 25.69 ± 9.77 42.57 ± 25.04 1.66 4.36 33.87 ± 19.92 1.32 3.47 11.09 27.26 20.84 1b 0.3 41.03 ± -- 40.37 ± 134.6 0.98 -- 53.27 ± 177.6 1.30 -- 2.32 14.56 3.30 1c 0.39 61.18 ± 3.80 45.44 ± 116.5 0.74 11.96 55.84 ± 143.2 0.91 14.70 20.49 24.06 20.79 1d 1.1 52.87 ± -- 55.71 ± 50.65 1.05 -- 48.61 ± 44.19 0.92 -- 26.61 7.09 11.71 1e 0.67 44.32 ± -- 52.05 ± 77.69 1.17 -- 48.61 ± 72.55 1.10 -- 28.21 2.69 2.69 4a 2.6 20.31 ± 25.12 17.37 ± 6.68 0.86 0.69 38.51 ± 14.81 1.90 1.53 3.10 4.09 34.33 4b 3.2 36.93 ± -- 22.81 ± 7.13 0.62 -- 40.0 ± 12.50 1.08 -- 5.79 11.0 27.15 4e 0.31 36.38 ± 32.36 56.33 ± 181.7 1.55 1.74 61.16 ± 197.3 1.68 1.89 3.86 2.25 4.19 4d 2.2 21.54 ± 26.30 63.73 ± 28.97 2.96 2.42 64.12 ± 29.15 2.98 2.44 2.66 3.52 1.56 4e 1.6 43.79 ± -- 50.78 ± 31.74 1.16 -- 48.93 ± 30.58 1.12 -- 27.96 25.76 23.55 7 2.2 6.39 ± -- 7.24 ± 4.45 3.29 1.13 -- 1.94 ± 0.88 0.30 -- 1.76 0.36 8a 0.62 5.78 ± 12.02 5.51 ± 2.73 8.89 0.95 0.46 5.55 ± 3.95 0.96 0.46 1.94 1.18 8b 2.84 9.71 ± -- 26.14 ± 9.20 2.69 -- 16.03 ± 5.64 1.65 -- 2.22 16.88 9.16 9a 1.4 5.30 ± 2.75 29.91 ± 21.36 5.64 10.88 16.54 ± 11.81 3.12 6.02 2.44 19.1 14.20 9b 1.1 6.96 ± 25.72 31.06 ± 28.24 4.46 1.21 20.14 ± 18.31 2.89 0.78 0.26 2.99 7.95 9c 0.4 -- 0.38 -- -- -- -- -- -- -- -- 9d 2.1 6.08 ± 5.01 26.99 ± 12.85 4.44 5.39 14.04 ± 6.69 2.31 2.80 2.47 16.90 6.39 9e 5.0 25.55 ± 8.31 20.72 ± 4.14 0.81 2.49 11.73 ± 2.35 0.46 1.41 14.85 16.73 4.39 10a 2.27 -- 8.31 -- -- -- -- -- -- -- -- 10c 0.64 21.44 ± 2.19 24.04 ± 37.56 1.12 10.98 16.50 ± 25.78 0.77 7.53 1.55 12.63 9.43 10d 0.62 13.79 ± -- 6.19 ± 0.70 9.98 0.45 -- 3.92 ± 6.32 0.28 -- 6.89 2.19 11a 1.07 20.07 ± 30.19 36.14 ± 33.78 1.80 1.20 45.69 ± 42.70 2.28 1.51 8.91 19.08 5.21 11b 5.14 15.67 ± 83.18 57.62 ± 11.21 3.68 0.69 102.23 ± 19.89 6.52 1.23 8.56 24.59 63.89 11c 3.11 -- 16.59 -- -- -- -- -- -- -- -- 11d 8.6 38.24 ± 25.12 34.18 ± 3.97 0.89 1.36 38.72 ± 4.50 1.01 1.54 12.91 17.45 5.74 11e 4.17 13.5 ± 19.49 39.67 ± 9.51 2.94 2.04 39.91 ± 9.57 2.96 2.05 5.19 2.96 0.25 11f 1.4 9.75 ± 20.89 42.13 ± 30.09 4.32 2.02 42.65 ± 30.46 4.37 2.04 1.14 2.59 1.29 12a 1.3 -- 12.88 -- -- -- -- -- -- -- -- 12b 1.5 -- 12.88 -- -- -- -- -- -- -- -- 12c 2.3 33.57 ± 9.54 28.12 ± 12.23 0.84 2.95 25.76 ± 11.20 0.77 2.70 6.17 2.54 1.63 12d 2.1 -- 50.11 -- -- -- -- -- -- -- -- 12e 0.98 -- 10.23 -- -- -- -- -- -- -- -- 13a 1.89 12.6 ± 2.46 14.3 ± 9.1 7.57 1.14 5.81 9.23 ± 4.89 0.73 3.75 10.4 0.67 13b 2.59 20.9 ± -- 14.0 ± 8.6 5.41 0.67 -- 30.8 ± 11.89 1.47 -- 0.3 6.2 mel- 0.22 2.13 ± 26.30 3.24 ± 0.56 14.73 1.52 0.12 2.47 ± 11.23 1.16 0.09 phalan 0.02 0.21__________________________________________________________________________ .sup.a Hydrobromide salts obtained from the free bases of 4a, 11a-c, e were used in the human tumor screen. The hydrobromide salt from tbe free base of 11d was employed in all screens. .sup.b The letters T1 indicate the therapeutic index values in the P388, L1210 and human tumor (ht) screens i.e. IC.sub.50 figures using Tlymphocytes/IC.sub.50 data for the neoplastic cells.
The cytotoxicity assays were chosen with a view to detecting potent cytotoxic agents and also in order to evaluate the predictions mentioned above. In addition, the screens were designed to discover compounds with preferential toxicity for neoplastic rather than normal cells. First, use of murine P388 and L1210 leukemic cells was employed since these tumors have been claimed to be good predictors of clinically useful anticancer drugs. Second, the human tumor assay employed approximately 55 tumor cell lines from different neoplastic diseases principally leukemia, melanoma, non-small cell lung, colon, central nervous system, ovarian, renal, prostate and breast cancers. If a 50% decrease in the growth of cells was not achieved at the highest concentration, i.e. 10 -4 M, this figure of 10 -4 M was still included in the calculation of the average IC 50 values. Hence the figures are mean graph midpoint values rather than true mean figures. Compounds which have a higher toxicity to one or more of these neoplastic diseases may display a greater activity towards these cancers than normal tissues. In addition, a comparison of the IC 50 figures in these three screens with those obtained using two human T-lymphocytes would enable the generation of therapeutic index (TI) figures. Thus compounds displaying selective toxicity to malignant cells may be revealed.
The biodata is reviewed in terms of the predictions made earlier and second, by an examination of the results obtained in each of the assays. In both approaches, a major goal was the determination of those molecular features which contribute to bioactivity.
In order to explore the viability of the hypotheses outlined previously and which are summarized in Table 4, comparisons were made between the average potencies of various series of compounds containing the same aryl substituents. Only three compounds were prepared in series 10 namely compounds 10a,c,d which were compared with compounds 9a,c,d and 12a,c,d. A positive correlation meant that the majority of comparisons favored the theory while a negative correlation indicated that most comparisons did not support the hypothesis. The data revealed the importance of the olefinic bonds while support for the sequential cytotoxicity concept was equivocal. Accordingly, it is contemplated that future analogs should incorporate unsaturated centers into their structures permitting alkylation of cellular nucleophiles to occur.
TABLE 4______________________________________Evaluation of the cytotoxicity data in light of the predictions made. prediction.sup.a P388 cells L1210 cells Human tumors______________________________________Thiol interactions 1 > 4 + + -- 9 > 11 + + + 10 > 9 + -- -- 10 > 12 + -- -- Sequential cytotoxicity 9 > 1 - + --______________________________________ .sup.a The symbols + and - indicate validation and negation of the theory while -- means that there was insufficient data to make a comparison.
The following observations were made pertaining to the P388 cytotoxicity data. All of the compounds had IC 50 figures of less than 10 μM and for 27% of the compounds, these values were less than 1 μM. Four compounds namely 1b,c, 4c and 9c possessed more than half the potency of melphalan. The average potencies for the compounds 1, 4, 9, 11a-e and 12 were 0.83, 1.98, 2.00, 4.42 and 1.64 μM respectively, while the figures for compounds 9a,c,d and 10a,c,d were 1.30 and 1.18 respectively. Clearly the significant antileukemic properties of the compounds in series 1 are noteworthy while the quaternary ammonium salts 10 and 12 had greater cytotoxicity than the corresponding tertiary amines 9 and 11 respectively. The average TI P388 values for series 1, 4, 9 and 11 compounds were 80.90, 51.24, 16.65 and 14.62 respectively when Molt 4/C8 lymphocytes were considered while the TI figures generated using CEM cells for these compounds were 91.49, 56.87, 9.79 and 19.17 respectively. Thus the acyclic compounds 1 and 4 have both lower average IC 50 values and higher therapeutic indices when compared to the cyclic structures 9 and 11 respectively. In general, these compounds possessed greater therapeutic indices than melphalan.
Table 3 indicates the activity of a number of the Mannich bases and related quaternary ammonium halides against murine L1210 lymphocytic leukemia cells. The activity ranged from 5.30 (9a) to 61.18(1c)μM. In all cases, these compounds were less active towards L1210 cells than the P388 leukemia cell line. Since the IC 50 values of compounds 9c and 11c were unavailable, the average IC 50 figures of compounds 1a,b,d,e, 4a,b,d,e, 9a,b,d,e and 11a,b,d,e were calculated and found to be 40.98, 30.64, 10.97 and 21.87 μM respectively. The average TI L1210 figures generated for these groups of compounds using Molt4/C8 cells were 1.22, 1.40, 3.84 and 2.33 respectively while use of CEM cells led to figures of 1.16, 1.77, 2.20 and 3.19 respectively. Thus in contrast to the use of P388 cells, greater cytotoxicity and therapeutic indices were found with the piperidines 9 and 11 than the analogous Mannich bases 1 and 4. In general, these compounds had higher therapeutic indices than melphalan.
Most of the compounds prepared in this study were assessed against a panel of human tumor cell lines. In order to make comparisons in which the aryl substituents were constant, the average IC 50 figures of the tertiary amines 1a,c, 4a,c, 9a,c and 11a,c were computed and found to be 6.79, 28.74, 1.57 and 23.39 respectively. In addition, the average IC 50 values of compounds 9a-e and 11a-e were 8.43 and 34.91 respectively while compound 10c possessed 4.36 times the activity of compound 12c. These data clearly reveal the following general correlations. First, compounds containing olefinic bonds (compounds 1, 9, 10) were more potent when compared to the analogs 4, 11 and 12 respectively. Second, the piperidines 9 and 11 were more cytotoxic than the related acyclic analogs 1 and 4 respectively. Selective toxicity towards leukemia was observed for four of the seven quaternary ammonium salts examined in this screen namely 10a, 12a, 12b and 12e; this property was also noted with compounds 1a and 9e. In addition, compound 9d had preferential cytotoxicity towards human colon cells. The TI ht figures using Molt 4/C8 cells for compounds 1a, 4a, 9a and 11a were 4.36, 0.69, 10.88 and 1.20 respectively while for compounds 9a,b,d,e and 11a,b,d,e the average values were 4.99 and 1.32 respectively. The data for compounds 10c and 12c were 10.98 and 2.95 respectively. Use of CEM T-lymphocytes revealed that the TI ht figures for compounds 1a, 4a, 9a and 11a were 3.47, 1.53, 6.02 and 1.51 respectively and for compounds 9a,b,d,e and 11a,b,d,e the average values were 2.73 and 1.58 respectively. The data for compounds 10c and 12c were 7.53 and 2.70 respectively. Thus the same conclusions regarding potency vide supra can be drawn for the TI values namely the presence of olefinic bonds and piperidine rings in those molecules lead to the greatest therapeutic indices. A noteworthy feature observed in the human tumour screen was the fact that approximately 80% of the compounds evaluated were more potent than melphalan and in particular compound 9c possessed 69 times the activity of this widely used drug.
All of the compounds had greater TI ht values than melphalan using both Molt4/C8 and CEM cells e.g. compound 1c had 100 and 163 times greater TI ht figures in the Molt4/C8 and CEM cells respectively than melphalan.
A comparison of the murine cytotoxicity data for compounds 1b and 7 was ambiguous pertaining to whether this molecular modification increased cytotoxicity or not. However the introduction of the geminal dimethyl groups was considered to be disadvantageous insofar as its marked cytotoxicity towards human T-lymphocytes led to inferior TI P388 and TI L1210 values than compound 1b.
In order to seek correlations between the cytotoxicity data and the electronic, hydrophobic and steric properties of the aryl substituents, linear and semilogarithmic plots between the IC 50 values and the Hammett σ, Hansch π and molar refractivity (MR) constants in each of the series 1, 4 and 9-12 compounds were made, providing that screening results were available for at least three members of a particular series. The test for zero correlation was applied at the 95% and 90% significance levels. In cases where good correlations were noted, the data was further evaluated revealing p values of less than 0.05. The significant relationships which were obtained are summarized in Table 5.
TABLE 5______________________________________Correlations between the sigma (σ), pi () and molar refractivity (MR) constants in the P388, L1210 and human tumor screens. Aryl substituent Screen Series constant Plot.sup.a p value.sup.b Correlation.sup.c______________________________________P388 1 MR lin, log <0.05, <0.1 + 4 MR lin, log <0.1, <0.05 + 9 σ lin, log <0.1, <0.005 + 9 lin, log <0.1, <0.05 + L1210 1 lin, log <0.1, <0.1 - 1 MR lin, log <0.025, <0.025 - 4 MR log <0.1 - Human 4 σ log <0.1 - tumors 4 lin, log <0.1, <0.1 - 4 MR lin, log <0.1, <0.1 - 9 log <0.1 +______________________________________ .sup.a Both linear (lin) and semilogarithmic (log) plots were made. .sup.b When two values are quoted, they refer to correlations obtained from the linear and logarithmic plots respectively. .sup.c Positive (+) correlations indicate that cytotoxicity rose as the σ, and MR values are increased while negative (-) correlations reveal that increased bioactivity occurred with diminishing σ, and MR figures.
The data in Table 5 reveal that eleven correlations between cytotoxicity and the σ, π and MR constants were noted in both the series of acyclic Mannich bases 1 and 4 as well as the piperidines of series 9. No correlations were discerned in the other three series of compounds namely 10-12. The relationships between cytotoxicity and the MR, π and σ values of the aryl substituents were noted in five, four and two cases respectively. Thus where correlations were detected, differences in the sizes and hydrophobic properties of the aryl groups influence activity more than their chemical reactivity.
As Table 5 indicates, positive correlations were noted with the P388 screen, negative relationships were found in the L1210 test and both positive and negative correlations were obtained using the human tumor assay. For example, and for future expansion of series 4, an increase in the size of the aryl substituent would be predicted to increase cytotoxicity in the P388 screen. On the other hand, a reduction in the MR value of the aryl group is expected to increase activity in the L1210 and human tumor assays. Similarly for series 1, while increases in the size of the aryl substituents would be expected to increase activity in the P388 screen, compounds containing aryl substituents with smaller MR values would be predicted to display increased cytotoxicity in the L1210 test.
As indicated previously, the majority of compounds described in this study demonstrated selective toxicity for neoplastic tissues. In order to evaluate whether these promising results could be translated into in vivo activity, two representative compounds 9d and 10a were chosen. Compound 9d had greater cytotoxicity to murine leukemic cells and human tumor cell lines than to T-lymphocytes while this compound and 10a demonstrated preferential cytotoxicity to colon and leukemic cells respectively in the human tumor assay. These two compounds were examined in the murine P388 screen and against certain human tumors in athymic mice. Evaluation in the P388 screen revealed that compound 9d was inactive and compound 10a displayed marginal potency whereby an increase in the life span of the mice by 20% was noted. The activity of these two compounds towards several xenografts is summarized in Table 6. Reductions in the sizes of the tumors were observed with both compounds and the potency of compound 9d against the COLO 205 tumor is of particular interest.
TABLE 6______________________________________Effect of 9d and 10a on various human tumor xenografts passaged in athymic mice. % T/C.sup.a % ILS.sup.b(dose in (dose in Compound Tumor Classification mg/kg) mg/kg)______________________________________ 9d COLO 205 colon 57 (200) 28 (200) SW-620 colon 32 (80) 9 (80) NCI-H522 non-small cell lung 23 (80) -2 (80) LOX IMVI melanoma 35 (80) 12 (80) 10a COLO 205 colon 20 (16.8) 14 (16.8) KM12 colon 45 (16.8) 5 (25) CAKI-1 renal 43 (16.8) 6 (16.8)______________________________________ .sup.a % T/C indicates the optimal value of the percentage reduction of the median treated tumor weight compared to the median control tumor weight. .sup.b % ILS refers to the percentage increase in the median time in days for the treated tumor to reach a certain size compared to controls.
Furthermore, the promising in vitro and in vivo activity of compound 9d suggested that analogs containing one or two nuclear methyl groups may also display selective toxicity to malignant cells. The data in Table 3 revealed that compounds 13a,b had comparable cytotoxicity to compound 9d. In general the TI ht values obtained when cytotoxicity towards murine leukemia cells and T-lymphocytes were compared were lower with compounds 13a,b than with compound d. However the TI ht figures of compounds 13a,b were both greater than compound 9d although neither 13a,b displayed selective toxicity for colon cancers (or any other neoplastic disease) in the human tumor screen.
It has been found that, in general, compounds containing olefinic bonds had greater cytotoxicity than analogs bereft of this functional group; however these latter compounds displayed cytotoxicity and therefore structural features other than the presence of chemically reactive double bonds contributed to bioactivity. A number of prototypic molecules emerged from this study based on the demonstration of selective toxicity for malignant tissue displayed by many of the compounds. In addition, the promising in vivo activity of compound 9d towards colon cancers was noteworthy.
EXAMPLE 3
Anticancer Studies
Chemistry. Melting points are uncorrected. Compounds 1a,d,c, 4a-e and 11a have been reported previously and, in general, had melting points similar to those recorded in the literature. Elemental analyses (C,H,N) were undertaken on compounds 1a-e, 4a-e, 7, 8a,b, 9a-e, 10a,c,d, 11a-c,e,f, 12a-e and 13a,b, as well as the hydrobromide salts of the free bases obtained from compounds 4a and 11a-e, and were within 0.4% of the calculated values. 1 H NMR spectra were determined using a Bruker AM 500 FT NMR machine (500 MHz) while a Varian T-60 (60 MHz) instrument was used to confirm the structures of intermediate α,β-unsaturated ketones. A Nonius CAD-4 diffractometer was used for the collection of X-ray crystallographic data. TLC was undertaken using silica gel plastic-backed sheets. All compounds were homogenous using solvent systems of hexane:methanol (7:3) for the intermediate α,β-unsaturated ketones, chloroform:methanol (7:3) for the Mannich bases and chloroform:methanol:ammonium hydroxide (7:3:0.08) for the quaternary ammonium salts. Compounds 8b, 11f, and 12c,d were obtained as the hemihydrates and 12a as the monohydrate. The percentage yields of the Mannich bases were calculated on the basis of the reactants used. For example, in the case of compound 4a the molar ratios of diethylamine hydrochloride, acetophenone and paraformaldehyde were 0.01, 0.04 and 0.03 respectively and the 55% yield recorded was based on the premise that a maximum yield would be 0.01 mole of pure product.
Synthesis of intermediate α,β-unsaturated ketones required in the preparation of 1, 7, 8a, 9 and 10. 4-Phenyl-3-buten-2-one was obtained from the Aldrich Chemical Company. The remaining styryl ketones were prepared by a known method and purified by recrystallization or distillation. The products had melting points or boiling points consistent with literature values. The structures were confirmed by 1 H NMR spectroscopy (60 MHz CDCl 3 ) and the spectrum of a representative compound, 4-(4-methoxyphenyl)-3-buten-2-one, was as follows. d:2.30 (s,3H,COCH 3 ), 3.80 (s,3H,OCH 3 ), 6.40-6.60 (d,1H,CH═CHCO,J=18 Hz), 6.70-7.50 (m,5H,aryl H,CH═CHCO).
Synthesis of series 1,4 and compound 7. A mixture of the appropriate 4-aryl-3-buten-2-one, 1-aryl-1-ethanone, or 1-aryl-4-methyl-1-penten-3-one, paraformaldehyde, diethylamine hydrochloride, trifluoroacetic acid (0.04 mL, 1a-e, 7) or hydrochloric acid (37% w/v, 0.04 mL, 4a-e) and acetonitrile (100 mL, 1a-e, 4a,c, 7) or isopropanol (100 mL, 4b,d,e) was heated under reflux for different periods of time. After removal of the solvent in vacuo, the resultant oil was triturated with anhydrous ether and subsequently with acetone. The solid obtained was washed with ether and recrystallized from ether-methanol (1c-e, 4a,d, 7), acetone (1a, 4b), acetonitrile (4c), ethanol-acetone (4e) or methanol (1b). A constant quantity of diethylamine hydrochloride was used throughout namely 0.01 mol. The molar ratios of ketone and paraformaldehyde, times of heating under reflux (h), yields (%;) and melting points (σC) were as follows. 1a: 0.03:0.03, 36, 61, 130-132; 1b: 0.03:0.03, 24, 68, 150-152; 1c: 0.03:0.03, 24, 54, 158-160, 1d: 0.03-0.03, 48, 48, 156-158; 1e: 0.03:0.03, 48, 89, 148-150; 4a: 0.04:0.03, 30, 55, 109-111; 4b: 0.025:0.03, 17, 61, 138-140; 4c: 0.03:0.025, 24, 67, 131-133; 4d: 0.04:0.03, 42, 53, 118-120; 4e: 0.04:0.03, 42, 63, 119-121; 7: 0.05:0.05, 48, 61, 160-162. The 1 H NMR (60 MHz) spectra of representative compounds in deuterochloroform were as follows. 1a: 1.2-1.66 (t,6H,CH 3 ), 2.83-3.6 (m,8H,CH 2 ), 6.4-6.73 (d,1H,olefinic H,J=16 Hz), 7.0-7.4 (m,5H,C 6 H 5 ); 7.4-7.67 (d,1H,olefinic H, J=16 Hz); 4a: 1.2-1.6 (t,6H,CH 3 ), 2.83-4.0 (m,8H,CH 2 ), 7.13-8.0 (m,5H,C 6 H 5 ); 7:1.0-1.6 [m,6H,N(CH 2 CH 3 ) 2 ], 1.6[s,6H,C(CH 3 ) 2 ], 2.66-3.5 (m,6H,CH 2 ), 7.06-7.33 (d,1H,olefinic H,J=16 Hz), 7.33-7.93 (m,4H,C 6 H 4 ), 7.66-7.93 (d,1H,olefinic H,J=16 Hz).
A series of 3-dimethylamino-1-aryl-1-propanone hydrobromides were prepared by known methods and this led to the synthesis of the hydrobromide salt of the free base of compound 4a in 15% yield. It was recrystallized from acetone-methanol, mp 104-107° C.
Synthesis of series 8, 9, 11 and 13. A mixture of the 4-aryl-3-buten-2-one or 1-aryl-1-ethanone, paraformaldehyde, piperazine dihydrochloride (8a,b), ethylamine hydrochloride (9a-e, 11a-c,e,f, 13a,b), or ethylamine hydrobromide (11d), hydrochloric acid (37% w/v, 0.04 mL, 8b, 9a-e, 11b,c, 13a,b) or trifluoracetic acid (0.04 mL, 11a,d,e; 3 mL, 11f) in acetonitrile (100 mL, 8a, 11a,d,e), ethanol (95% v/v, 100 mL, 8b, 9a-e, 13a,b) or isopropanol (100 mL, 11b,c,f), was heated under reflux for varying lengths of time. In the case of 11b, the product which deposited from the reaction mixture was collected and washed with isopropanol. For the other compounds, the solvent was removed in vacuo leading to oils which were washed with ether and dissolved in ethanol (10 mL) to which ether was added to induce precipitation. After refrigerating the solution at 4° C. for 2-3 days, the deposited solids were collected and recrystallized from ethanol (60%, 8a), ethanol (70%, 8b), ethanol (95%, 9a,c, 11a,b), ether-methanol (9b,d,e, 11d,e, 13b), or methanol (11c,f, 13a). A constant quantity of amine hydrohalide was used (0.01 mol). The molar ratios of ketone to paraformaldehyde, times of heating (h), yields (%) and melting points (°C.) were as follows: 8a: 0.04:0.03, 4, 61, 234(dec.); 8b: 0.06:0.06, 17, 41, 198(dec.); 9a: 0.06:0.04, 36, 57, 194-196; 9b: 0.06:0.04, 30, 24, 210-212; 9c: 0.08:0.08, 24, 63, 192-194; 9d: 0.06:0.04, 42, 21, 190-192; 9e: 0.05:0.05, 45, 25, 180-182; 11a: 0.04:0.04, 20, 47, 208-210; 11b: 0.03:0.025, 48, 71, 202-203; 11c: 0.03:0.025, 24, 70, 185-187; 11d: 0.04:0.04, 20, 50, 198-200; 11e: 0.04:0.04, 48, 56, 178-179; 11f: 0.05:0.05, 48, 51, 178-180; 13a: 0.06:0.04, 36, 30, 164-166 and 13b: 0.06:0.04, 72, 28, 172-174.
The hydrobromide salts of the free bases from 11a,c,e were prepared as follows. A solution of the bis Mannich base (0.01 mol) in water (50 mL) was basified with sodium bicarbonate solution (10% w/v) and extracted with ether (5×25 mL). The organic extracts were combined and dried (anhydrous magnesium sulfate) and removal of the solvent gave a residue which was dissolved in anhydrous ether (100 mL). Excess of dry hydrogen bromide was passed into the ethereal solution at 0° C. and the precipitate was collected, washed with anhydrous ether and chilled ethanol and dried. The reaction products were recrystallized from isopropanol to give the hydrobromide salts of the free bases from the following compounds namely 11a, mp 183-184° C., 11c, mp 182-184° C. and 11e, mp 176-178° C. The free bases of 11b,d were obtained using the method described for the preparation of series 10 and 12 vide infra. Addition of dry hydrogen bromide gas to an ice-cooled solution of the Mannich base (0.001 mol) in ether (50 mL,) led to precipitates which were collected, dried and recrystallized from isopropanol to give compound 11b, mp 196-198° C. or ether-methanol leading to compound 11d, mp 192-194° C.
Synthesis of 10a,c,d and Series 12. A stirring solution of the piperidinols 9a,c,d, 11a-e (0.001 mol) in aqueous methanol (20%; v/v, 25 mL) was cooled and maintained at less than 10° C. while basified with aqueous sodium bicarbonate solution (10 w/v). The mixture was extracted with ether (5×25 mL) and dried (anhydrous magnesium sulfate). Removal of the solvent under vaccuum gave an oil which was dissolved in anhydrous ether (50 mL) to which was added methyl bromide (0.01 mol) at 0° C. The reaction mixture was stirred at 0° C. for 6 h. The precipitates were collected, washed with dry ether, dried and recrystallized from ethanol (95% % v/v, 10a,b) or ether-methanol (10c, 12a-e). The yields (%) and melting points (°C.) were as follows. 10a: 77, 178-179; 10c: 70, 202-204; 10d: 78, 222-224; 12a: 86, 192-194; 12b: 73, 164-166; 12c: 79, 168-170; 12d: 80, 152-154; 12e: 76, 188-190. TLC of the reaction products obtained in a similar manner from compounds 9b and 9e revealed the presence of an impurity. Recrystallization and column chromatography did not lead to the isolation of a pure compound.
X-ray crystallography of 8b, 10d, 12d, 13a and 13b. Compound 8b crystallized from 95% ethanol by slow evaporation while the other Mannich bases were recrystallized from diethyl ether:methanol (10d), propan-2-ol:methanol (12d), cyclohexane:methanol (13a) and hexane:ethanol (13b) by vapor diffusion. A Nonius CAD-4 diffractometer with a ω scan was used for data collection and the structure was solved by direct methods using NRCVAX and refined using SHELX93. Atomic scattering factors were taken from the literature. All non-hydrogen atoms were found on the E-map and refined anisotropically. Hydrogen atom positions were calculated and not refined. Compound 8b had a partially occupied water molecule while 13a and 13b had one molecule of methanol and three water molecules respectively present as solvents.
The data for 8b were as follows: C 22 H 26 N 2 O 2 Cl 2 , M r =421.34, a=11.189(2), b=7.4387(9), c=14.257(2)Å, β=110.999(12), Z=2, space group=P2 1 /a monoclinic, D x =1.263 gcm -3 , λ(MoKα)=0.7093Å,T=287 K. Merging R is based on intensities 0.029 for 111 replicate reflections. Refinement on F 2 ; R[F 2 >2s(F 2 )]=0.0565, wR(F 2 )=0.1747, S=1.09. A total of 2053 reflections were measured of which 1942 were independent and used in the refinement of the structure. Parameters refined=135, [w=1[σ 2 (F o 2 )+(0.0866P) 2 +0.4689P] where P=(F o 2 +2F c 2 )/3. Δρ in the final difference map within +0.513 and -0.577e Å -3 .
The data for 10d were as follows: C 27 H 33 BrNO 2 , M r =483.45, a=8.0240(9), b=10.253(2), c=15.594(5)Å, α=74.398(23), β=83.549(16), γ=86.847(14), Z=2, space group=P1, triclinic, D x =1.308 gcm -3 , λ(MoKα)=0.7093Å, T=123 K. Merging R is based on intensities 0.015 for 447 replicate reflections. Refinement on F 2 , R[F 2 >2σ(F 2 )=0.0598, wR(F 2 )=0.1797, S=1.52. A total of 4790 reflections were measured of which 4343 were independent and used in the refinement of the structure. Parameters refined=280, [w=1[σ 2 (F o 2 )+(0.1222P) 2 +0.000P] where P=(F o 2 +2F c 2 )/3. Δρ in the final difference map within +2.094 and -0.469e Å -3 .
The data for 12d were as follows: C 23 H 30 INO 2 ,M r =479.38, a=8.2245(10), b=9.6745(10), c=14.067(2)Å, α=87.821(9), β=87.785(8), γ=83.530(8), Z=2, space group-P1, triclinic, D x =1.167 gcm -3 , λ(MoKα)=0.7093Å, T=287 K. Merging R is based on intensities 0.010 for 206 replicate reflections. Refinement on F 2 ; R[F 2 >2σ(F 2 )]=0.0341, wR(F 2 )=0.0972, S=1.081. A total of 3356 reflections were measured of which 3150 were independent and used in the refinement of the structure. Parameters refined=241, [w=1/[σ 2 (F o 2 )+(0.0530P) 2 +1.2322P] where P-(F o 2 +2F c 2 )/3. Δρ in the final difference map within +1.112 and -0.691e Å -3 .
The data for 13a were as follows: C 26 H 32 ClNO 2 .CH 3 OH, M r =458.02, a=16.1710(11), b=7.8499(7), c=20.1754(11)Å, β=100.916(5) 0 , Z=4, space group=P2 1 /c, monoclinic, D x =1.210 gcm -3 , λ(MoKα)=0.7093, T=287 K. Merging R is based on intensities 0.013 for 141 replicate reflections. Refinement on F 2 ; R[F 2 >2σ(F 2 )]=0.0420, wR(F 2 )=0.1359, S=1.139. A total of 4555 reflections were measured of which 4414 were independent and used in the refinement of the structure. Parameters refined=289, [w=1[σ 2 (F o 2 )+(0.0785P) 2 +0.4236P] where P=(F o 2 +2F c 2 )/3. Δρ in the final difference map within +0.320 and -0.333e Å -3 .
The data for 13b were as follows: C 28 H 36 ClNO2.3H 2 O, M r =504.51, a=9.8839(7), b=10.1341(7), c=15.5788(9)Å, α=95.996(5), β=99.206(5), γ=108.956(5), Z=2, space group=P1, triclinic, D x =1.167 gcm -3 , λ(MoKα)=0.7093Å, T=287 K. Merging R is based on intensities 0.007 for 284 replicate reflections. Refinement on F 2 ; R[F 2 >2σ(F 2 )]=0.0584, wR(F 2 )=0.1905, S=1.104. A total of 4459 reflections were measured of which 4175 were independent and used in the refinement of the structure. Parameters refined=313, [w=1/[σ 2 (F o 2)+(0.1121P) 2 +0.9444P] where P=(F o 2 +2F c 2 )/3. Δρ in the final difference map within +0.462 and -0.559e Å -3 .
Bioevaluation
Cytotoxicity Assays. Evaluation of the compounds using P388 D1 cells was undertaken by a known procedure and the examination with L1210 cells and T-lymphocytes was achieved using a previously reported method. The assay of various compounds using human tumors has been described. Cell lines from the following diseases were employed namely leukemia, non-small cell lung, colon, central nervous system, melanoma, ovarian, renal, prostate and breast cancers. Compounds 9a,b, 10a, 11d and 12a,e were not evaluated against prostate and breast cancers but they were tested against small cell lung tumors.
In vivo evaluation of 9d and 10a
The compounds were examined by the Developmental Therapeutics Program, National Cancer Institute, U.S.A. The murine P388 lymphocytic leukemia assay was conducted by a reported known method and the maximum ILS figures for 9d and 10a were 5 and 20% respectively using doses of 54 and 6.7 mg/kg respectively. An increase of 20% or more in the life spans is considered to be statistically significant. A reference drug 5-fluorouracil has an ILS of >35 using a dose of 20 mg/kg when given intraperitoneally for five days. Passage of human tumors in athymic mice was undertaken by a known method. No definitions of activity are available but as a general rule compounds causing a 60% reduction in tumor weights in one of these screens would be evaluated further. For example cyclophosphamide, while inactive towards COLO 205, SW-620 and NCI-H522 xenografts, reduced the growth of the LOX IMVI and CAKI-1 tumors by 100-150% and 60-100% respectively.
EXAMPLE 4
Anti-fungal Studies
In addition, the in vitro and in vivo activity of compound 9b against Aspergillus fumigatus was investigated. As well, the in vivo activity of compound 9b against Candida albicans in ovariectomized rats was determined.
Materials and Methods
Organisms: Clinical isolates of Aspergillus fumigatus were obtained from the Microbiology Laboratory of the Detroit Medical Center, Wayne State University, Detroit, Mich.
Amphotericin B-resistant and itraconazole-resistant Aspergillus fumigatus isolates were selected in the laboratory from a clinical isolate (W73355) that was susceptible to amphotericin B and itraconazole. All fungal cultures were routinely grown in PYG (peptone 1 g; yeast extract 1 g; glucose 3 g; per liter of distilled water) medium at 35° C. Working cultures were maintained on PYG agar slants at 4° C.; long-term storage of the cultures was done 25% glycerol at -70° C.
Determination of MIC and MLC: The susceptibility of Aspergillus fumigatus to various drugs was determined using a broth macrodilution technique. Briefly, fresh conidia were collected from A fumigatus and resuspended in PYG medium at a density of 2×10 4 conidia per ml. Two times the required concentrations of the drugs were prepared in PYG medium (0.5 ml) by serial dilution in sterile 6 ml polystyrene tubes (Falcon 2054) and inoculated with an equal volume (0.5 ml) of the conidial suspension. The tubes were incubated at 35° C. for 48 hr and scored for visible growth after vortexing the tubes gently, or scraping the walls of the tube followed by vortexing, MIC was defined as the lowest concentration of the drug in which no visible growth occurred.
To determine the MLCs, the entire cell suspension from the tubes that contained drugs equal to and greater than the MIC was spread on PYG agar (0.1 ml per plate) and incubated at 35° C. for 2 days growth. The concentration of the drug that provided ≦10 CFU/ml was considered as the MLC. MIC and MLC determinations were performed at least twice and the values were within ±one dilution.
Kill-Curve Experiment: 5 ml conidial suspension each of the AMB-, and ITZ-susceptible (W73355) and the resistant (AB16.4 and ITZ70) isolates prepared in PYG broth (1×10 6 conidia/ml) was incubated at 35° C. in the presence of 5 μm of AMB or 5 μm ITZ or 50 μm Compound 9b. At various time intervals, 0.1 ml aliquots of the conidial suspension were removed, diluted appropriately to obtain 10 2 to 10 4 fold dilution, and 0.1 ml aliquots were spread in duplicate on PYG agar plates. The plates were incubated at 35° C. for 48 hr and the number of CFU/ml of conidial suspension were calculated and plotted against the time of exposure to the drug for the construction of a kill-curve. Identical treatment of the conidial suspension in the absence of the drug was used as the growth control.
In vivo susceptibility studies: DBA/2J female mice (Jackson Laboratories) weighing 20-23 grams (≈6 weeks old) were used. The mice were immunosuppressed by 3 consecutive subcutaneous injections (0.5 ml each) of cortisone acetate (250 mg/kg; Sigma Chemical Company) in sterile distilled water containing 0.1% Tween 80. The immunosuppressed mice were anesthetized by exposing to ether in a desiccator for 45±5 seconds and infected with 20 μl inoculum containing 1×10 6 conidia delivered to the nares of the animals as a single droplet from a micropipet. Compound 9b and AMB were dissolved in dimethyl sulfoxide (DMSO) and administered 24 hr post infection by intraperitoneal injection in 0.2 ml PBS per dose. Control groups received comparable amount of DMSO in PBS. The efficacy of chemotherapy was assessed by determining percent survival and the fungal load (CFU/lungs) of infected animals as determined by semiquantitative organ culture.
As well, ovariectomized rats predisposed for Candida albicans infection by estrogen treatment were infected vaginally with 1×10 7 CFU per ml to produce vaginal candidiasis. The infected animals were treated with Compound 9b once daily (100 mg/kg=2 mg/mouse) for 5 days. Vaginal fluid was collected from each animal 72 hr post-treatment and CFUs per rat were determined by plating the ravage fluid on PYG agar containing 200 ug/ml gentamicin.
Chemicals: Compound 9b (FIG. 1; College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada), AMB (Batch No. 20-914-29670, Squibb Institute for Medical Research, Princeton, N.J.) and ITZ (R51 211, Batch No. STAN-9304-005-1, Janssen Pharmaceutica, Belgium) were dissolved in dimethyl sulfoxide (DMSO) at a concentration of 10 mm and stored as 0.25 ml aliquots at -20° C. The frozen stock was thawed at room temperature and vortexed gently several times to ensure that any remaining crystals were completely dissolved before use. Comparable concentrations of DMSO were used to examine its effect on the growth of A. fumigatus. No detectable inhibition of growth occurred at the concentrations used. Since AMB is light sensitive, the stock solutions and the MIC tubes were covered with aluminum foil to prevent from light exposure. The following range of concentrations were used in the study; AMB, 0-36 μm; ITZ, 0-36 μm; Compound 9b, 0-100 μm.
Susceptibility studies: The inhibitory effect of Compound 9b on Aspergillus fumigatus is presented in Table 7. The mean MIC value for the Aspergillus fumigatus was 11.87+5.32 μm. Comparisons were made between the activity of Compound 9b and the conventional antifungal agents such as itraconazole (ITZ) and amphotericin B (AMB). The data in Table 7 revealed that overall Compound 9b is less effective than ITZ and AMB in susceptible isolates. Of interest to note is the efficacy of this compound against Aspergillus fumigatus isolates that are resistant to AMB and ITZ. The MLC values of Compound 9b for various Aspergillus fumigatus isolates were, in general, either the same as or twofold higher than the MIC values. The fact that the MLC values of Compound 9b for Aspergillus fumigatus showed only a modest rise in comparison to the MIC values suggested that this styryl ketone is a fungicidal agent for Aspergillus fumigatus. As shown in FIG. 2, exposure of Aspergillus fumigatus conidia to Compound 9b rapidly lost their viability. Compound 9b at 50 μm provided≧90% killing within 24 hr whereas under the same conditions AMB and ITZ provided≧99% and 85% killing, respectively. Both AMB-resistant and ITZ-resistant isolates of Aspergillus fumigatus were as susceptible to the fungicidal activity of Compound 9b as the susceptible one (data not shown).
TABLE 7______________________________________Susceptibility of Aspergillus fumigatus to the investigational Compound 9b and established antifungal agents. MLC Antifungal MIC Range MIC (μM) Range Organism agent (μM) Mean ± SD (μM)______________________________________Aspergillus Compound 9b 6.25-25 11.87 ± 5.32 12.5-25 fumigatus Itraconazole 0.18-0.72 0.53 ± 0.16 ND (n=20) Amphotericin B 0.55-2.22 1.32 ± 0.63 ND AMB-resistant Compound 9b 6.25-12.5 9.85 ± 3.53 12-25 Aspergillus Itraconazole 0.32-1.29 0.82 ± 0.35 ND fumigatus Amphotericin B 4.42-17.7 6.64 ± 3.47 ND (n=18) ITZ-resistant Compound 9b 3.12-25 10.93 ± 6.35 6.25-25 Aspergillus Itraconazole 5.19-20.77 17.23 ± 5.83 ND fumigatus Amphotericin B 0.27-1.11 0.70 ± 0.39 ND (n=28)______________________________________ Note: For comparison MIC values are expressed in μM. ND = not determined.
Murine pulmonary aspergillosis: The in vivo susceptibility of Aspergillus fumigatus to Compound 9b was examined using a murine pulmonary aspergillosis model. As shown in FIG. 3, the survival of infected animals treated with Compound 9b did not improve significantly over the placebo group which was treated with DMSO. On the other hand, the fungal load (as determined by semi-quantitative lung culture) of animals infected with Aspergillus fumigatus was reduced significantly (FIG. 4). For example, animals treated with Compound 9b at a dose of 6.25 mg/kg/day showed 50% reduction in CFU/lung whereas AMB at 2 mg/kg/day provided ≈66% reduction of CFU/lung suggesting that Compound 9b is not as efficient as AMB for the reduction of fungal load. Under the same conditions, the placebo group treated with a comparable amount of DMSO provided only 16% reduction in CFU/lung. These results suggest that A. fumigatus is susceptible to Compound 9b both in vitro and in vivo.
Antifungal Cytotoxic properties of Compound 9b: Although Compound 9b showed good antifungal activity against Aspergillus fumigatus a concern was the toxicity of this compound since it has the ability to act as an alkylating agent. Therefore, we studied the cytotoxic effect of Compound 9b using various animal cells. The mean IC 50 value for 55 different human tumour cells was 25.72 μm. The evaluation of the IC 50 values against Molt 4/C8 and CEM human transformed T-lymphocytes were 31.06 μm and 20.14 μm, respectively. These values are approximately 2-3 fold higher than the mean MIC value obtained for Aspergillus fumigatus.
Antifungal properties of Compound 9b in Ovariectomized rats
Results obtained from treatment of ovariectomized rats having a Candida albicans infection is shown in Table 8.
TABLE 8______________________________________Results of treatment of ovariectomized rats having a Candida albicans infection. % CFU Animal Treatment CFU/rat Mean Value ± S.D. reduction______________________________________1 Mineral Oil 4.4 × 10.sup.5 4.5 × 10.sup.5 ± 2.2 × 10.sup.5 0.0 2 1.1 × 10.sup.5 3 6.2 × 10.sup.5 4 6.7 × 10.sup.5 5 5.7 × 10.sup.5 6 2.6 × 10.sup.5 1 Compound 9b 4.6 × 10.sup.4 1.2 × 10.sup.4 ± 1.7 × 10.sup.4 97.4 in Mineral Oil 2 4.2 × 10.sup.3 3 8.3 × 10.sup.2 4 1.7 × 10.sup.4 5 3.5 × 10.sup.2 6 6.5 × 10.sup.3______________________________________
Approximately 90 compounds belonging to the conjugated styryl ketone class were screened for their activity against pathogenic yeasts and filamentous fungi. The majority of the compounds tested were acyclic and had a single site for thiol alkylation reaction. The antifungal activity of these compounds ranged from modest activity to no activity, and the MIC values ranged from 0.1-1.5 mm. Since none of the previously examined compounds provided encouraging results for further studies, a series of α,β-unsaturated ketones with two sites for thiol alkylation reaction were synthesized. Among four such compounds examined, Compound 9b possessed activity against both pathogenic yeasts and filamentous fungi at low concentrations. Although Compound 9b possessed good fungicidal activity against Aspergillus fumigatus, the concentrations required are much higher than the currently available drugs (AMB and ITZ) against Aspergillus fumigatus.
One of the targets of a number of bioactive drugs is the nucleic acids. These interactions while leading to useful therapeutic effects in certain cases such as the alkylating agents used in cancer chemotherapy, have the potential for inducing mutagenicity and/or carcinogenicity. With a view to circumventing these potential problems, α,β-unsaturated ketones have been designed to interact solely or principally with thiols and thus to display zero or minimal affinity for the amino functions found in nucleic acids. Various experiments confirmed the thiol-specificity of these compounds. To augment their chemical reactivity towards thiols, the styryl ketones were converted to their Mannich bases, and they were shown to be devoid of mutagenic properties in the Ames test.
Thiol alkylating agents are generally highly toxic and used as therapeutic agents only in extreme cases. Since Compound 9b is an alkylating agent, the toxicity of this compound at high concentrations was of concern. Therefore, a number of experiments were performed to assess the cytotoxic effect of the compound using mammalian cells in culture. The mean IC 50 value was only 2-3 fold higher than the mean MIC value obtained for Aspergillus fumigatus. Moreover, the murine pulmonary aspergillosis model suggested that animals treated with Compound 9b at 6.5 mg/kg/day for five days did not show any greater mortality rate than the placebo or the AMB-treated groups. If the compound is highly toxic to animals at the concentrations used, a greater mortality rate would have been obtained when Compound 9b was used.
Possible mechanism(s) of action of Compound 9b were considered. Of interest was the observation that the thiol interaction was reversible with low molecular weight thiols but irreversible with protein thiols. In addition, representatives of this group of compounds inhibited mitochondrial function in a strain of Saccharomyces cerevisiae. Furthermore, thiol blockers such as omeprazole inhibited the proton translocating ATPase of Saccharomyces cerevisiae.
EXAMPLE 5
Apoptosis Studies
As indicated above, a group of Mannich bases having marked cytotoxicity towards murine P388 and L1210 leukemic cells has been found. These compounds have displayed a potent cytotoxicity towards human tumor cell lines from a number of neoplastic diseases. For example, compound 12d was five times more potent than melphalan against the human tumor cell lines. In general, these compounds were far less toxic to Molt4/C8 and CEM human T-lymphocytes than to both the murine leukemic and human tumor cells leading to favourable therapeutic indices (IC50 versus T lymphocytes/IC50 versus neoplastic cells). In addition, compound 9d displayed selective toxicity to human colon cancer cells. This observation suggested its in vivo evaluation and a 60% reduction in the weight of the human COLO 205 colon tumor passaged in athymic mice was noted.
The evolution of new anticancer drugs having chemical structures divergent from currently available medication is essential in order to treat cancers for which today's therapy is inadequate or nonexistent and should possess mechanisms of action which may enable treatment of drug-resistant cancers. In this study, the question posed was whether compound 9d, a representative of a new class of cytotoxic and anticancer agents, would cause apoptosis in human Jurkat T leukemia cells.
Materials and Methods
Materials
RPMI 1640 medium, gentamycin, melphalan, acridine orange, trypan blue, ethidium bromide were obtained from Sigma Chemical Co. (St.Louis, Mo., USA). Hyclone fetal calf serum was obtained from PDI Joldon (Aurora, Ontario, Canada). Human Jurkat T cells, LV-50, H-9 and Molt-3 cells used were obtained from K. Rigo and D. Neville (NIH).
Stock solutions of Compound 9d were prepared in DMSO at concentrations of 0.01, 0.1 and 1 mM and stored at -20° C. Freshly prepared stock solutions of melphalan in DMSO (0.01, 0.1 and 1 mM) were used for the apoptosis studies. A trypan blue dye solution [0.04% in phosphate buffer saline (PBS), pH 7.4] was used for counting living cells. A dye mix consisting of 100 μg/ml acridine orange and 100 μg/ml of ethidium bromide, both prepared in PBS, were used for the identification of apoptotic cells (Duke and Cohen, 1992) using an epifluorescence microscope (Model 2071, American Optical).
Cell culture conditions
All cell cultures used were maintained in RPMI 1640 medium, pH 7.4 supplanted with 10% fetal bovine serum and 50 μg/ml of gentamycin in 25 ml culture flasks at 37° C. in a humidified gas mixture of 5% carbon dioxide balanced with air and were passaged three times a week.
Cell viability assay
Cell viability was determined by the trypan blue exclusion test according to a literature procedure (Duke and Cohen, 1992). The tissue culture flasks containing a suspension of ˜10 6 cells/ml in 10 ml RPMI medium were treated with different concentrations of compound 9d (1.0, 2.0, 4.0, 6.0 and 8.0 μM). Similarly cells in separate culture flasks were treated with different concentrations of melphalan (0.125, 0.5, 2.0, 10.0 and 50 μM). A flask containing ˜10 6 cells/ml and 8 or 50 ml of DMSO was used as the control. All flasks were incubated for 48 hours at 37° C. in a 5% humidified carbon dioxide atmosphere. After 48 hours, cells were counted using a haemocytometer. The percentage of growth inhibition was calculated as follows: (C-T/C)×100 where C is the mean cell number in the control and T is the mean cell number in each treatment. The concentration needed to reduce the growth of the cells in culture to 50% of the control values (IC 50 ) was determined for both melphalan and Compound 9d from the graph drawn between the percentage cell growth inhibition as a function of dose. All experiments were performed in triplicate.
Morphological studies
Fluorescence microscopy using DNA binding fluorescent dyes such as acridine orange and ethidium bromide were employed to study the morphology of the Jurkat T cells undergoing apoptosis by an established procedure (Duke and Cohen, 1992). This mode of cell death was investigated in Jurkat T cells at two arbitrarily chosen concentrations of the test compound i.e. 6 and 10 μM. Cell cultures containing 6 or 10 μM of DMSO were treated as control. For comparison, an alkylating agent melphalan, which has been shown on several occasions to induce cell death by apoptosis in a variety of cell lines (Dyson et al., 1986), was also tested at one concentration i.e. 10 μM. Briefly, tissue culture flasks containing ˜10 6 cells/ml in 10 ml RPMI medium and an appropriate concentration of the test compound or melphalan or DMSO (control) were incubated at 37° C. in a 5% humidified CO 2 atmosphere. At the end of 5, 8, 11, 14 and 17 hours, 25 μl of the cell suspension from each flask was mixed with 1 μl of dye mix in a glass tube. Of this mixture, 10 μl was placed on a clean heamocytometer covered with a coverslip and a minimum of 200 cells were counted separately by two individuals with a 100× dry objective using the epifluorescence microscope. The percentage of apoptotic cells (apoptotic index) was calculated as follows. ##EQU1## Results
Effect of Compound 9d and melphalan on survival of human Jurkat T cells
Initial studies in which the effect of Compound 9d on Jurkat T, LV-50, H-9 and Molt-3 cells were measured showed that the Jurkat T cells were the most sensitive in its response, although all cell cultures were affected (FIG. 5). Further studies measuring the effect of Compound 9d on apoptosis and cell death were therefore undertaken using the Jurkat T cells only. Evaluation of Compound 9d and melphalan against Jurkat T cells using the trypan blue exclusion test showed a good dose dependent cytotoxicity (FIG. 6). The growth of Jurkat T cells was inhibited by 50% at concentrations of 3.46 and 1.16 μM for Compound 9d and melphalan respectively.
Induction of apoptosis by Compound 9d and melphalan in human Jurkat T cells
During 17 hours of study, several morphological features characteristic of apoptosis were identified in Jurkat T cells after its exposure to Compound 9d or melphalan. These drug effects were detectable after 3 hours. Acridine orange which is taken up by both live and dead cells, stained DNA green while ethidium bromide which is taken up only by dead cells stained DNA bright orange. By using this differential fluorescence between acridine orange and ethidium bromide, only three types of cells could be seen under the present experimental conditions. First, there were cells with bright green chromatin with normal nuclei (FIG. 7). Second, there were viable cells with apoptotic nuclei (bright green chromatin which is highly condensed and fragmented, FIG. 8). Third, very few non viable cells with normal nuclei (bright orange chromatin with organized structure) were seen during the whole period of study. The fourth type of cells which are the non viable cells with apoptotic nuclei, (bright orange chromatin which is highly condensed or fragmented) are usually observed after this differential fluorescence procedure but were not visible under our experimental conditions. In most of the apoptotic cells, the entire nucleus was present as one or a group of featureless bright spherical beads (apoptotic bodies) and the overall brightness was less than that of untreated cells. The untreated cells retained their morphology during the time period of the studies and even up to 48 hours. At the end of 48 hours, all the treated cells had died and only fragments of the cells could be seen.
As shown in FIG. 9, the apoptotic index increased with time for both melphalan and Compound 9d. Also as the dose of Compound 9d was increased from 6 to 10 μM, the apoptotic index increased almost two fold. At the same concentration (10 μM), Compound 9d showed a greater apoptotic index than melphalan. The percentage of apoptotic cells after 17 hours of treatment with 6 and 10 μM of Compound 9d had increased from an average of 4.4% in control Jurkat T cells to 22 and 43%, respectively, while in case of melphalan (10 μM) it was 24% only.
In order to perform an analysis of DNA fragmentation by agarose gel electrophoresis, DNA was collected from fractions corresponding to 6 and 10 μM concentrations of Compound 9d and 10 μM concentration of melphalan. A faint DNA ladder could be seen in the case of melphalan (data not shown) whereas Compound 9d at both concentrations did not show any DNA ladder under these conditions.
The aim of this example was to determine whether a representative from a new series of Mannich bases induced cell death by apoptosis or necrosis. The effect of one of the compounds from this class of compounds namely Compound 9d was investigated in human Jurkat T cells. The results showed that both Compound 9d and melphalan induced apoptosis as shown by the morphological characteristics in this cell line. Although melphalan was more cytotoxic than Compound 9d as shown by the trypan blue exclusion test, the latter compound was a more potent inducer of apoptosis (FIG. 9). One of the distinctive features of apoptosis is the fragmentation of DNA into multimers of approximately 200 base pairs, due to the activation of an endonuclease. However no DNA fragmentation was detected when Jurkat T cells were exposed to Compound 9d using concentrations of 6 and 10 μM after 10, 17 and even 48 hours of incubation. A faint DNA ladder could be seen in the case of melphalan (10 μM) after 17 hours of incubation. It is important to note that during this period of incubation very few cells were dead (these were characterized by being orange in color due to the uptake of ethidium bromide caused by a loss of membrane integrity). Hence it is probable that the key morphological changes in apoptosis observed in the current experiments are preceding the internucleosomal cleavage of DNA. Some recent studies which demonstrated that DNA fragmentation is not an essential feature of apoptosis since it may be delayed or absent in cell death that appears by other criteria to be apoptotic (Cohen et al., 1992, Collins et al., 1992; Ucker et al., 1992) supports this observation.
In conclusion the example reveals that Compound 9d is a potent apoptotic agent.
The compounds of the invention may be administered in the form of compositions with inert pharmaceutically-acceptable compounds, for example diluents (eg. calcium phosphate dihydrate, calcium sulfate dihydrate, cellulose, dextrose, lactose, mannitol, starch, sorbitol, sucrose and sucrose-based materials), binders and adhesives (eg. acacia, cellulose derivatives, gelatin, glucose, polyvinylpyrrolidone (PVP), alginates, sorbitol, pregelatinzied starch or starch paste and tragacanth), disintegrants (eg. alginates, cellulose and cellulose derivatives, clays, cross-linked PVP, starch and starch derivatives), lubricants (eg. polyethylene glyconyls, stearic acids, salts and derivatives, surfactants, talc and waxes), glidants (cornstarch, silica derivatives and talc), and colors, flavors and sweeteners (eg. FD & C, and D & C, dyes and lakes, flavor oils and spray-dried flavors, artificial sweeteners and natural sweeteners). Typical salts are halide salts, such as the chloride, bromide, etc.
The terms and expressions which have been employed in this specification are used as terms of description and not of limitations, and there is no intention in the use of such terms and expressions to exclude any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claims.
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Mannich bases of conjugated styryl ketones have been developed which are effective as cytotoxicity and anticancer agents, and which also have antifungal activity. Preferred compounds are those of the formula ##STR1## where R 1 is Cl, CH 3 or OCH 3 and R 2 is H or Cl. A compound of particular interest is (3-[3-(4-chlorophenyl)-2-propenoyl]-4-[2-(4-chlorophenyl)vinylene]-1-ethyl-4-piperidinol hydrochloride.
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BACKGROUND OF THE INVENTION
Various types of safety valves for gas tank have been constructed in the past for controlling the flow passing therethrough. However, they cannot be used to measure the flow rate nor detect gas leakage. Further, they must be closed by hand thereby causing much inconvenience and wasting energy when the user forgets to close them.
It is, therefore, an object of the present invention to provide an improved safety gas valve.
SUMMARY
It is the primary object of the present invention to provide a safety gas valve which is provided with a timer.
It is another object of the present invention to provide a safety gas valve with timer which is simple in construction.
It is still another object of the present invention to provide a safety gas valve with timer which is easy to operate.
It is still another object of the present invention to provide a safety gas valve with timer which is provided with a flow rate meter.
It is a further object of the present invention to provide a safety gas valve with timer which will give signals when the timer stops allowing the passage of gas.
Other objects, merits and features of the present invention will be obtained by those having ordinary skill in the art when the following detailed description of the preferred embodiment contemplated for practicing the invention has been read in conjuntion with the accompanying drawings, wherein like numerals refer to like or similar parts and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present invention;
FIG. 2 is a cross-sectional view of the present invention;
FIG. 3 shows the slot of the valve body;
FIG. 4 shows the closed state of the present invention; and
FIG. 5 shows the open state of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings and in particular to FIGS. 1 and 2 thereof, the present invention comprises a safety valve 1 and a timer 3. The safety valve 1 has a knob 11, a compressed spring 12, a stop packing 13, a positioning spring 14, a plug 15, an oil seal 16, a push rod 17, a rubber cup 18, and a valve body 19. As shown in FIG. 2, the knob 11 is shaped as a cup provided on the top with a rib 111. The center of the rib 111 has a threaded hole for engaging with a screw 112. The screw 112 extends through the knob 11 to engage with the push rod 17. The interior of the knob 11 is formed with an annular projection 113 having a recess for receiving the end of the plug 15 so that the knob 11 will rotate in unison with the plug 15. The plug 15 has a longitudinal through hole for receiving the push rod 17. Furthermore, the plug 15 has a tapered right end (with respect to FIG. 2) on which there are two aligned exits 151 each having a ferrule 152 therein.
The rubber cup 18 is adapted to the tapered right end of the plug 15 and having two holes 181 in alignment with the exits 151 of the plug 15. As the rubber cup 18 is put on to the tapered end of the plug 15 and located within the valve body 19, the rubber cup 18 will be able to rotate in unison with the plug 15. The rubber cup 18 is mainly used for sealing.
The valve body 19 is hollow in structure and can just accomodate the component parts. On the circumferential surface of the valve body 19 there is a Z-like slot 191 capable of accomodating a positioning pin 114 mounted in the knob 11. The lower portion of the valve body 19 is provided with a through hole 192 having the same diameter as the hole 181 of the rubber cup 18. The through hole 192 is formed at both ends with internal threads.
In assembly a ball 20 is first put into the through hole provided at the lower portion of the plug 15. Then, the rubber cup 18 is put on to the tapered end of the plug 15 and disposed within the valve body 19. Thereafter, put the oil seal 16 on to the push rod 17 and insert the push rod 17 into the longitudinal through hole of the plug 15. Afterwards, the positioning spring 14 is mounted coaxially with the central portion of the plug 15. A stop packing 13 is then put on to the positioning spring 14 and its rim is embedded into the valve body 19. Then, the compressed spring 12 is put on to the free end of the plug 15, pressing against the stop packing 13. The screw 112 extends through the knob 11 to engage with the push rod 17. Lastly, the positioning pin 114 is mounted in the knob 11 and extends into the slot 191 of the valve body 19.
From the above, it is understood that the present invention has the following characteristics:
1. The positioning spring 4 will force the plug 15 to closely engage with the rubber cup 18 and so the rubber cup 18 will have effective sealing function.
2. The ball 20 is always located between the two ferrules 152 at the exits 151 of the plug 15.
3. The knob 11 can be pressed in unison with the push rod 17 to press the ball 20.
4. The knob 11 are rotated in unison with the plug 15 and the rubber cup 18 so as to control the connection between the exits 151 and the valve body 19.
Normally, the safety gas valve is at the closed condition. At that time, the knob 11 will be lifted by the compressed spring 12 to the upper end of the slot 191, the bottom end of the push rod 17 is not in contact with the ball 20, and the exits 151 are not in communication with the through hole 192.
When desired to supply gas, simply press the knob 11 and then turn the knob 11 along the slot 191 to the leftmost end with respect to FIG. 1. Meanwhile, the exits 151 will communicate with the through hole 192 thereby allowing the passage of the gas.
When the gas piping is damaged, there will be a large amount of gas leakage thereby producing transient vacuum and therefore, causing the ball 20 to press on the upper ferrule 152. As a result, the exits 151 will be closed and gas leakage will be stopped. When desired to supply gas after maintenance, press the knob 11 to lower the push rod 17 to separate the ball 20 from the upper ferrule 152. In the meantime, the pressure is balanced, the vaccum disappears, the ball 20 will not block the ferrule 152, and gas can pass therethrough again.
Referring to FIGS. 3 and 4, the timer 3 is disposed within a block 31. The block 3 has a gas exit 32 in both sides. In the lower part of the block 31 is formed a recess 33 having a passage in communication with the timer 3. A lift rod 34 is disposed within the passage, with its top end bearing against a hitting rod 42 of the timer 3. The lift rod 34 has an opening 36 at its central portion and an annular projection 37 at its lower portion. In assembly, a rubber packing 40 is first put on to the annular projection 37 of the lift rod 34. Then, a spring 38 is engaged with the bottom end of the lift rod 34. Thereafter, the recess 33 is put on to a connector 41 thereby confining the spring 38 into the recess 33 and therefore, urging the lift rod 34 against the hitting rod 42 of the timer 3.
The timer 3 mainly comprises a set of timing gears, a notched disc 39, an actuating arm 35 and a hitting rod 42. When the timer 3 is at its zero point, a protuberance 351 of the actuating arm 35 will go into the notch 391 of the notched disc 39. Meanwhile, the lower edge 352 of the actuating arm 35 does not urge against the hitting rod 42. Accordingly, the lift rod 34 is lifted by the spring 38 to its upper position. As the lift rod 34 is lifted, the rubber packing 40 will be lifted to urge against the top of the recess 33, blocking the gas passage. When the timer 3 is set, the edge of the notched disc 39 will force the protuberancce 351 of the actuating arm 35 to move downwards thereby causing the lower edge 352 of the actuating arm 35 to press the hitting rod 42 downwards (as show in FIG. 5). At that time, the rubber packing 40 will be separated from the top 331 of the recess 33 and gas may flow through the center hole of the connector 41 and the recess 33 to the gas exits 32. When the timer 3 returns to its zero point, the protuberance 351 of the actuating arm 35 will go into the notcch 391 of the notched disc 39 again.
It should be noted that when the protuberance 351 of the actuating arm 35 returns to fall into the notch 391 of the notched disc 39, the end 421 of the hitting rod 42 will be oscillated to strike abell 43. Hence, the user will be given a signal when the time is up.
Referring to FIG. 2 again, a pitot tube 50 is mounted into the safety valve 1 and operatively connected with the vertical through hole 192 of the valve body 19 so that the flow rate of the gas can be measured.
Although this invention has been described with a certain degree of particularity, it is understood that the present disclosure is made by way of example only and that numerous changes in the detail of construction and the combination and arrangement of parts may be resorted to without departing from the scope and spirit of the invention as hereinafter claimed.
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This invention relates to a safety gas valve with timer, and in particular to one combining a valve and a timer together, whereby it can be set to close automatically at predetermined time and can be used to detect gas leakage.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Continuation Application of U.S. application Ser. No. 12/015,243 filed Jan. 16, 2006, which is a Continuation Application of U.S. application Ser. No. 11/228,410 filed Sep. 19, 2005, now issued U.S. Pat. No. 7,331,646 which is a Continuation Application of U.S. application Ser. No. 11/007,319 filed Dec. 9, 2004, now issued as U.S. Pat. No. 7,044,585, which is a Continuation Application of U.S. application Ser. No. 10/270,153 filed Oct. 15, 2002, now issued U.S. Pat. No. 6,834,932, which is a Continuation of U.S. application Ser. No. 09/575,117 filed May 23, 2000, now issued as U.S. Pat. No. 6,464,332, all of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of ink jet printing and in particular discloses a method and apparatus for the compensation for the time varying nozzle misalignment of a print head assembly having overlapping segments.
CO-PENDING APPLICATIONS
[0003] Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention with the present application:
[0000]
6,428,133
6,526,658
6,315,399
6,338,548
6,540,319
6,328,431
6,328,425
6,991,320
6,383,833
6,464,332
6,390,591
7,018,016
6,328,417
6,322,194
6,382,779
6,629,745
09/575,197
7,079,712
6,825,945
7,330,974
6,813,039
6,987,506
7,038,797
6,980,318
6,816,274
7,102,772
7,350,236
6,681,045
6,728,000
7,173,722
7,088,459
09/575,181
7,068,382
7,062,651
6,789,194
6,789,191
6,644,642
6,502,614
6,622,999
6,669,385
6,549,935
6,987,573
6,727,996
6,591,884
6,439,706
6,760,119
7,295,332
6,290,349
6,428,155
6,785,016
6,870,966
6,822,639
6,737,591
7,055,739
7,233,320
6,830,196
6,832,717
6,957,768
7,456,820
7,170,499
7,106,888
7,123,239
6,409,323
6,281,912
6,604,810
6,318,920
6,488,422
6,795,215
7,154,638
6,924,907
6,712,452
6,416,160
6,238,043
6,958,826
6,812,972
6,553,459
6,967,741
6,956,669
6,903,766
6,804,026
7,259,889
6,975,429
[0004] The disclosures of these co-pending applications are incorporated herein by cross-reference.
BACKGROUND OF THE INVENTION
[0005] In the applicant's co-pending application PCT/AU98/00550, a series of ink jet printing arrangements were proposed for printing at high speeds across a page width employing novel ink ejection mechanisms. The disclosed arrangements utilized a thermal bend actuator built as part of a monolithic structure.
[0006] In such arrangements, it is desirable to form larger arrays of ink ejection nozzles so as to provide for a page width drop on demand print head. Desirably, a very high resolution of droplet size is required. For example, common competitive printing systems such as offset printing allow for resolutions of one thousand six hundred dots per inch (1600 dpi). Hence, by way of example, for an A4 page print head which is eight inches wide, to print at that resolution would require the equivalent of around 12800 ink ejection nozzles for each colour. Assuming a standard four colour process, this equates to approximately fifty one thousand ink ejection nozzles. For a six colour process including the standard four colours plus a fixative and an IR ink this results in 76800 ink ejection nozzles. Unfortunately, it is impractical to make large monolithic print heads from a contiguous segment of substrate such as a silicon wafer substrate. This is primarily a result of the substantial reduction in yield with increasing size of construction. The problem of yield is a well studied problem in the semi-conductor industry and the manufacture of inkjet devices often utilizes semi-conductor or analogous semi-conductor processing techniques. In particular, the field is generally known as Micro Electro Mechanical Systems (MEMS). A survey on the MEMS field is made in the December 1998 IEEE Spectrum article by S Tom Picraux and Paul J McWhorter entitled “The Broad Sweep of Integrated Micro Systems”.
[0007] One solution to the problem of maintaining high yields is to manufacture a lengthy print head in a number of segments and to abut or overlap the segments together. Unfortunately, the extremely high pitch of ink ejection nozzles required for a print head device means that the spacing between adjacent print head segments must be extremely accurately controlled even in the presence of thermal cycling under normal operational conditions. For example, to provide a resolution of one thousand six hundred dots per inch a nozzle to nozzle separation of about sixteen microns is required.
[0008] Ambient conditions and the operational environment of a print head may result in thermal cycling of the print head in the overlap region resulting in expansion and contraction of the overlap between adjacent print head segments which may in turn lead to the production of artifacts in the resultant output image. For example, the temperature of the print head may rise 25° C. above ambient when in operation. The assembly of the print head may also be made of materials having different thermal characteristics to the print head segments resulting in a differential thermal expansion between these components. The silicon substrate may be packaged in elastomer for which the respective thermal expansion coefficients are 2.6×10 −6 and 20×10 −6 microns per degree Celsius.
[0009] Artifacts are produced due to the limited resolution of the print head to represent a continuous tone image in a binary form and the ability of the human eye to detect 0.5% differences in colour of adjacent dots in an image.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide for a mechanism for compensating for relative displacement of overlapping print head segments during operation in an effective and convenient manner.
[0011] In accordance with a first aspect of the invention there is provided in an ink ejection print head comprising a plurality of overlapping print head segments, wherein the spatial relationship between adjacent segments is variable with time, a method for controlling the firing of nozzles within the overlapped segments comprising the steps of: (a) determining a measure of the overlap between adjacent print head segments; (b) creating a half toning pattern for the nozzles in the region of overlap of the overlapping segments; and (c) adjusting said half toning pattern as a function of said measure in the overlapping regions of said print head segments to reduce artifacts produced by the overlapping of said print head segments.
[0012] Preferably, the step for determining a measure of overlap employs a measure of temperature of the print head segments The half toning patterns are preferably produced by means of a dither matrix or dither volume and the alteration can comprise adding an overlap value to a current continuous tone pixel output value before utilizing the dither matrix or dither volume. In place of a measure of temperature a measure of distance can be provided by the use of fiduciary strips on each of the segments and using an interferometric technique to determine the degree of relative movement between the segments.
[0013] In accordance with a further aspect of the present invention, there is provided an ink ejection print head system comprising: a plurality of spaced apart spatially overlapping print head segments; at least one means for measurement of the degree of overlap between adjacent print head segments; means for providing a half toning of a continuous tone image and means for adjusting said half toning means in a region of overlap between adjacent print head segments to reduce artifacts between said adjacent segments.
[0014] The means for adjusting the half toning means can include a continuous tone input, a spatial overlap input and a binary input, the half toning means utilizing the spatial overlap input to vary the continuous tone input to produce a varied continuous tone input for utilization in a look-up table of a dither matrix or dither volume so as to produce output binary values to adjust for the regions of overlap of print head segments. The means for adjusting the half tone or dither matrix may be implemented in hardware or by means of software employing an algorithm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] This invention is pointed out with particularity in the appended claims. The above and further advantages of this invention may be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which:
[0016] FIG. 1 shows a schematic of a pair of adjacent print head segments according to the invention;
[0017] FIG. 2 illustrates the process for printing dots from adjacent print head segments as shown in FIG. 1 ;
[0018] FIG. 3 illustrates a process of blending dots between adjacent print head segments according to the invention;
[0019] FIG. 4 illustrates a process of dither matrix variational control according to an embodiment of the invention;
[0020] FIG. 5 illustrates a process of dither matrix variational control according to another embodiment of the invention; and
[0021] FIG. 6 illustrates graphically an algorithm implementing a further process of dither matrix variational control according to a further embodiment of the invention.
[0022] FIG. 7 shows a schematic of a pair of adjacent printhead segments according to a further embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] In a first embodiment, a method of compensation for the temperature varying relative displacement of adjacent print head segments is provided by the utilization of a digital processing mechanism which adjusts for the overlap between adjacent segments.
[0024] In a print head covering an A4 page width there may be 10 segments having 9 overlapping portions arranged in a repeating sequence of staggered pairs. Initial alignment of segments can be made within 10 microns using techniques well known in the art of monolithic fabrication techniques. The width of a segment for a 6 colour ink arrangement would be approximately 225 microns assuming the nozzles of a segment are arranged on 16 micron centres in a zig-zag pattern longitudinally.
[0025] In this embodiment, a temperature sensor is placed on each print head segment so as to provide for a measure of the current temperature characteristics of each print head segment. The current temperature measurement can then be utilized to determine the amount of overlap between adjacent print head segments.
[0026] Alternatively, only a single temperature sensor can be used if it can be assumed that the segments of the print head are sufficiently similar to one another in physical characteristics and performance and that the ambient milieu of each pair of overlapped segment is substantially the same.
[0027] The degree of overlap is then used to provide a mechanism for controlling the half toning between adjacent print head segments. It is assumed that outputting of an image in the instant invention is by means of digital half toning employing any method or technique well known in the art. Many different half toning techniques can be utilized and reference is made to the text by Ulichney entitled “Digital Half Toning” published by MIT Press.
[0028] As shown in FIG. 1 adjacent print head segments 2 , 3 overlap in the respective regions 12 , 13 . The overlap region may extend approximately 40 thou (˜1 mm.) providing an overlap of 64 nozzles spaced at 16 microns for 1600 dpi resolution.
[0029] A temperature sensor 16 is placed on each print head segment 2 , 3 so as to provide for a measure of the current temperature characteristics of each print head segment 2 , 3 . The current temperature measurement can then be utilized to determine the amount of overlap between adjacent print head segments. Alternatively, fiduciary strips 100 , 101 on each overlapped segment 102 , 103 , as shown in FIG. 7 , may be used to measure the degree of relative displacement of the segments 102 , 103 by an interferometric technique.
[0030] In the region 10 of the segment 2 the nozzles of this segment are used exclusively for the ejection of ink. Similarly in the region 11 of the segment 3 the nozzles of this segment are used exclusively for the ejection of ink. In the overlapping regions 12 , 13 a “blend” is provided between the two print head segments 2 , 3 such that along the edge 14 of the print head segment 2 nozzles are used exclusively in the region 12 to print and similarly along the edge 15 , the nozzles of the segment 3 are used almost exclusively for printing. In between, an interpolation, which can be linear or otherwise, is provided between these two extreme positions. Hence, as shown in FIG. 2 , when printing a full colour output on a page the area on the side 17 is printed exclusively by the print head segment 10 while the area 18 is printed exclusively by the print head segment 11 (as illustrated by the black dots) with the area 19 comprising a blend between the nozzles of the two segments. The printing process utilizes any well known half toning matrix such as disclosed in the aforementioned references. While a known half toning matrix is utilized, the actual print head segment utilized will depend upon the blending ratio provided by the measure of overlap between the overlapping segments.
[0031] One such method is illustrated in FIG. 3 where a linear interpolation within the overlapped regions is shown. In the region corresponding to the overlapped section 12 at the edge 14 there is 100% utilization of the nozzles of print head segment 2 , whereas in the equivalent region, edge 7 , of the print head segment 3 there is zero output. As the distance of the overlap region from the line 14 of the segment 2 is increased towards the line 15 of the segment 3 the proportion of utilization of the nozzles of the section 12 is gradually decreased (linearly), being zero at edge 9 while the utilization of the nozzles of the section 13 is progressively increased to unity by the time the edge 15 is reached. In a first embodiment, where there is an increased overlap between nozzles, the half toning thresholds utilized are increased in the overlap region. This reduces the number of dots printed in the blend region. Conversely, if there is a reduced overlap with the print head segments being spaced apart slightly more than normally acceptable, the dot frequency can be increased by reducing the half toning threshold.
[0032] An overall general half toning arrangement can be provided as shown in FIG. 4 with a dither matrix 25 outputting a current dither value 26 to a summation means 27 with summation means 27 having another input 28 , an overlap signal, which varies in either a positive or a negative sense depending on the degree of overlap between the adjacent segments. The output value 29 of summation means or adder 27 is compared to the input continuous tone data 32 via a comparator 30 so as to output half tone data 31 . An alternative arrangement allows that the data value 28 can be subtracted from the continuous tone data 29 before dithering is applied producing similar results. This arrangement is shown in FIG. 5 .
[0033] As shown in FIG. 5 , a halftone data output 52 can be generated by combining the output 42 of dither matrix 40 in an adder 46 with the overlap signal 44 , and then taking the difference of the output 54 of adder 46 and the continuous tone data 48 in subtractor 50 . This is an equivalent arrangement to that of FIG. 4 .
[0034] Through the utilization of an arrangement such as described above with respect to FIGS. 3 and 4 , a degree of control of the overlap blending can be provided so as to reduce the production of streak artifacts between adjacent print head segments.
[0035] As each overlap signal 28 can be multiplied by a calibration factor and added to a calibration offset factor, the degree of accuracy of placement of adjacent print head segments can also be dramatically reduced. Hence, adjacent print head segments can be roughly aligned during manufacture with one another. Test patterns can then be printed out at known temperatures to determine the degree of overlap between nozzles of adjacent segments. Once a degree of overlap has been determined for a particular temperature range a series of corresponding values can be written to a programmable ROM storage device so as to provide full offset values on demand which are individually factored to the print head segment overlap.
[0036] A further embodiment of the invention involves the use of a software solution for reducing the production of artifacts between overlapped segments of the print heads. A full software implementation of a dither matrix including the implementation of an algorithm for adjusting variable overlap between print head segments is attached as appendix A. The program is written in the programming language C. The algorithm may be written in some other code mutatis mutandis within the knowledge of a person skilled in the art. The basis of the algorithm is explained as follows.
[0037] A dispersed dot stochastic dithering is used to reproduce the continuous tone pixel values using bi-level dots. Dispersed dot dithering reproduces high spatial frequency, that is, image detail, almost to the limits of the dot resolution, while simultaneously reproducing lower spatial frequencies to their full intensity depth when spatially integrated by the eye. A stochastic dither matrix is designed to be free of objectionable low frequency patterns when tiled across the page.
[0038] Dot overlap can be modelled using dot gain techniques. Dot gain refers to any increase from the ideal intensity of a pattern of dots to the actual intensity produced when the pattern is printed. In ink jet printing, dot gain is caused mainly by ink bleed. Bleed is itself a function of the characteristics of the ink and the printing medium. Pigmented inks can bleed on the surface but do not diffuse far inside the medium. Dye based inks can diffuse along cellulose fibres inside the medium. Surface coatings can be used to reduce bleed.
[0039] Because the effect of dot overlap is sensitive to the distribution of the dots in the same way that dot gain is, it is useful to model the ideal dot as perfectly tiling the page with no overlap. While an actual ink jet dot is approximately round and overlaps its neighbours, the ideal dot can be modelled by a square. The ideal and actual dot shapes thus become dot gain parameters.
[0040] Dot gain is an edge effect, that is it is an effect which manifests itself along edges between printed dots and adjacent unprinted areas. Dot gain is proportional to the ratio between the edge links of a dot pattern and the area of the dot pattern. Two techniques for dealing with dot gain are dispersed dot dithering and clustered dot dithering. In dispersed dot dithering the dot is distributed uniformly over an area, for example for a dot of 50% intensity a chequer board pattern is used. In clustered dot dithering the dot is represented with a single central “coloured” area and an “uncoloured” border with the ratio of the area of “coloured” to “uncoloured” equaling the intensity of the dot to be printed. Dispersed dot dithering is therefore more sensitive to dot gain than clustered dot dithering.
[0041] Two adjacent print head segments have a number of overlapping nozzles. In general, there will not be perfect registration between corresponding nozzles in adjacent segments. At a local level there can be a misregistration of plus or minus half the nozzle spacing, that is plus or minus about 8 microns at 1600 dpi. At a higher level, the number of overlapping nozzles can actually vary.
[0042] The first approach to smoothly blending the output across the overlap bridge and from one segment to the next consists of blending the continuous tone input to the two segments from one to the other across the overlap region. As output proceeds across the overlap region, the second segment receives an increasing proportion of the input continuous tone value and the first segment receives a correspondingly decreasing proportion as described above with respect to FIG. 3 . A linear or higher order interpolation can be used. The dither matrices used to dither the output through the two segments are then registered at the nozzle level.
[0043] The first approach has two drawbacks. Firstly, if the dither threshold at a particular dot location is lower than both segments' interpolated continuous tone values then both segments will produce a dot for that location. Since the two dots will overlap, the intensities promised by the two dither matrices will be only partially reproduced, leading to a loss of overall intensity. This can be remedied by ensuring that corresponding nozzles never both produce a dot. This can also be achieved by using the inverse of the dither matrix for alternating segments, or dithering the continuous tone value through a single dither matrix and then assigning the output dot to one or the other nozzle stochastically, according to a probability given by the current interpolation factor.
[0044] Secondly, adjacent dots printed by different segments will overlap again leading to a loss of overall intensity.
[0045] As shown in FIG. 6 , the value for each overlapped segment is plotted along the horizontal axes 60 , 62 as V A and V B respectively between the values of 0.0 and 1.0. The calculated output 66 is plotted with respect to the vertical axis 64 as a function, I A+B , for values ranging from 0.0 to 1.0. A contour plane 68 shows the resultant values for I A+B =0.5.
[0046] FIG. 6 shows the qualitative shape of the three dimensional function linking the two segments' input continuous tone values V A and V B to the observed output intensity I A+B . For the first approach, an input continuous tone value V and an interpolation factor f together yield V A =(1−f)V and V B =fV. The closer the interpolation factor is to 0.5 the greater the difference between the input continuous tone value and the observed output intensity. For V=1.0, this is illustrated in FIG. 6 by the curve 200 on the vertical V A +V B =1.0 plane. By definition this curve lies on the function surface. FIG. 6 indicates that when any kind of mixing occurs, that is 0.0<f<1.0, the output intensity is attenuated, and to achieve the desired output intensity the sum of the two segments' input values must exceed the desired output value, that is V A +V B >V. This forms the basis for the algorithm in appendix A.
[0047] The function shows a linear response when only one segment contributes to the output, that is f=0.0 or f=1.0. This assumes of course that the dither matrix includes the effects of dot gain.
[0048] The foregoing description has been limited to specific embodiments of this invention. It will be apparent, however, that variations and modifications may be made to the invention, with the attainment of some or all of the advantages of the invention. For example, it will be appreciated that the invention may be embodied in either hardware or software in a suitably programmed digital data processing system, both of which are readily accomplished by those of ordinary skill in the respective arts. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.
APPENDIX A
[0049] A full software implementation of a dither matrix including the implementation of an algorithm for adjusting variable overlap between print head segments is provided below. The program is written in the programming language C.
static
void
ObtainMisregistrationTransferFunction
[0050] (
[0051] int dotsPerPixel,
[0052] int subdotsPerDot,
[0053] BI_Image const& dotImage,
[0054] char const* pDotImageName,
[0055] char const* pRefDotImageName,
[0056] int const overlapSize,
[0057] int const overlapIndex, //0 . . . overlapSize−1
[0058] int const misregFactor,
[0059] BI_Image const& ditherMatrix,
[0060] BI_LUT& lutv,
[0061] BI_LUT& lut0,
[0062] BI_LUT& lut1
[0000] );
class RLE_DotLine
{
public:
RLE_DotLine( )
: m_whiteRun(0), m_blackRun(0) { }
RLE_DotLine(int whiteRun, int blackRun)
: m_whiteRun(whiteRun), m_blackRun(blackRun) { }
[0067] int WhiteRun( ) const {return m_whiteRun;}
[0068] int BlackRun( ) const {return m_blackRun;}
[0000] private:
[0069] int m_whiteRun;
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A method of generating halftone print data for overlapping end portions of a pair of consecutive printhead segments in an array of two or more printhead segments. Generally an end portion of a first printhead segment overlaps an end portion of a second printhead segment, in which each printhead segment includes a plurality of ink ejection nozzles. The method includes generating a dither value from a dither matrix, and then combining the dither value with an overlap signal, which represents an extent of overlap of the end portions, to produce an output value. A mathematical operation is then performed on continuous tone print data using a comparator, based on the output value, to produce the half tone data.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sewing machine which gives a warning signal when the amount of under thread has reduced to a predetermined value.
2. Description of the Prior Art
In the usual sewing operation, upper or needle thread is supplied from a relatively large bobbin, while the under thread is supplied from a relatively small bobbin located beneath the sewing plate. Therefore, the operator has to frequently check the under thread bobbin to see if the amount of remaining thread is sufficient to complete a stitch without interruption.
Japanese Pat. No. 72-17586 discloses a device for detecting when the amount of remaining under thread reaches a predetermined value to give a warning signal. This device comprises a rotary hook having an opening therein and a bobbin case having an identical opening. When the openings of the rotary hook and the bobbin case are aligned to each other on a particular phase during rotary motions, a spring-loaded probe is automatically inserted into the aligned openings to make contact with the circumference of the under thread wound on the bobbin cylinder. When the amount of the under thread has reduced to a predetermined value the probe triggers a warning circuit to alert the operator. This probe is mounted on a pivot which rotates in synchronism with the rotary motion of the rotary hook so as to give a rocking movement to the probe. Since the probe is brought into contact with the under thread in the radial direction, this tends to give a considerable amount of impact to the under thread tension, so that the latter is drawn up with an increased tension when the probe is in contact therewith, which tends to give unsatisfactory results.
SUMMARY OF THE INVENTION
The present invention contemplates the use of an axially spring-biased cylindrical member which is rotatably mounted for unitary rotation with the bobbin and axially movable between first and second positions. When the bobbin shaft is fully wound through its axial length by the under thread, the spring-biased cylindrical member is held in the first position against the edge of the thread layers. When the amount of the under thread has reduced to a predetermined value, the cylindrical member is moved to the second position by the action of the spring. This axial displacement of the cylindrical member is detected to trigger a warning signal.
Preferably, the cylindrical portion of the bobbin is formed with a larger and a smaller diameter portion and the axially biased rotary cylindrical probe member is received in the larger diameter portion for unitary rotation therewith. In response to the consumption of the under thread on the larger diameter portion of the bobbin cylinder, the cylindrical member is caused to move from the first to second positions. The operator is thus allowed to continue sewing operation with the remaining under thread which is wound on the smaller diameter portion of the bobbin cylinder. A second cylindrical probe member is axially movably mounted on the bobbin case shaft and urged toward the first cylindrical probe member for unitary axial movement therewith, and provided with a projecting probe which extends through an opening provided in the bobbin case and projects from its forward end surface when the first cylindrical member is in the first position. The warning signal is derived from a proximity detector when the block member is axially displaced to a retracted position in response to the axial movement of the first cylindrical member. This proximity detector is mounted on a pivoted arm which is normally in a retracted position to clear off the area adjacent to the rotary hook to facilitate mounting of the bobbin case into the rotary hook shaft and moved to an operative position in which the detector is located in proximity to the sensing block member.
An object of the present invention is therefore to provide a sewing machine which gives a warning signal for the under thread without interfering with the normal sewing operation.
Another object of the invention is to provide an under thread detector which is simple in structure and easy to be mounted on the sewing machine.
A further object of the invention is to provide an under thread detector which is easily adapted to the existing sewing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described by way of example with reference to the accompanying drawings, in which:
FIG. 1 is a front view of the bobbin case embodying the present invention shown mounted within a rotary hook;
FIG. 2 is a cross-sectional view taken along the lines 2--2 of FIG. 1;
FIG. 3 is an exploded perspective view of the embodiment of FIG. 2 with the bobbin case being omitted;
FIG. 4 is a cross-sectional view of the embodiment of FIG. 1 with all the components being nestled together within the bobbin case and a schematic circuit diagram of a proximity detector shown located in proximity to the front surface of the bobbin case;
FIG. 5A is an end view illustrating a flange of the bobbin according to a modified embodiment of the invention;
FIG. 5B is an end view illustrating another flange of the bobbin of the modified embodiment;
FIG. 5C is a side view of the modified bobbin;
FIGS. 6 to 8 are various modifications of the proximity detector; and
FIG. 9 is a front view of the proximity detector shown mounted on a pivoted arm.
DETAILED DESCRIPTION
Referring now to FIGS. 1 to 3, an embodiment of the present invention is illustrated as comprising a bobbin case 10 having a cylinder 12 with an axially extending throughbore 14 therein through which the shaft 16 of the rotary hook 18 is journalled as in the conventional manner. The bobbin case 10 is formed with an opening 20 on its front wall 22. The bobbin 24 comprises a cylinder 26 and flanges 28 and 30 at opposite ends of the cylinder 26. The cylinder 26 is formed with a smaller diameter section 32 adjacent to the flange 30 and a larger diameter section 34 adjacent to the flange 28. Between the larger and smaller diameter sections is formed a varying diameter section 33, with the diameter increasing from the smaller to the larger diameter sections. The smaller diameter section 32 has an axially extending bore 36 which is journalled through the cylinder 12 when the bobbin is rotatably mounted therein. The larger diameter section 34 has a bore 38 coaxial with the bore 32 and is formed with a set of three axially extending cutouts or guide slots 40. A cup-shaped cylindrical probe member 42 is provided which is formed with a set of three radially extending projections or guide flanges 44 and a bore 46 having the same diameter as the diameter of the bore 36. When the bobbin 24 is received in the bobbin case 10 the probe member 42 is received in the larger diameter section 34 with the flanges 44 being received respectively in the corresponding guide slots 40 of the larger diameter section 34.
An axially movable cylindrical probe member 45 is provided which comprises a cylinder 46 with a flange 48 and a round-surfaced block or projecting probe 50 mounted forward of the cylinder 46 by an extension arm 52. Around the cylinder 46 is provided a coiled spring 54 which axially extends between the inner wall 15 of the bobbin case 10 and the flange 48. The probe member 45 is journalled through the shaft 12 of the bobbin case 10 and axially movable between a forward position in which the projecting probe 50 projects from the front wall 22 of the bobbin case as illustrated in FIG. 4 and a rearward position in which the probe 50 is retracted from the front end wall 22. The spring 54 urges the axially moving probe 45 to the right as well as the rotary probe member 42 toward the smaller diameter section 32 of the bobbin 24. The axial probe 45 and rotary probe 42 are nestled together within the bobbin case 10 as illustrated in FIG. 4 and prevented from being dislocated therefrom by means of a ring 55.
As in the conventional manner, the bobbin 24 is detachably and rotatably mounted on the shaft 12 of the bobbin case 10 with under thread being coiled around through the axial length of the larger and smaller diameter sections of its cylinder 26. The under thread is so wound that its beginning end starts on the smaller diameter section 32 and when the amount of that thread measured in the radial direction reaches the circumference of the larger diameter section 34 the thread is shifted to the larger diameter section 34 and levels off through the axial length of the cylinder 26 until it is wound to the outer edge of the flanges 28, 30.
With the under thread being wound on the bobbin 24, the latter is rotatably mounted when in operation on the shaft 12 of the bobbin case 10, so that the rotary probe member 42 is received in the larger diameter section 34 with its flanges 44 being fitted respectively into the guide slots 40, as illustrated in FIG. 4. The bobbin case 10, with all the elements being accommodated therein, is mounted on the shaft 16 as in the conventional manner. When the bobbin 24 is fully loaded with the thread, the flanges 44 of the probe 42 are held by the spring 54 against the overlying turns of the thread wound on the larger diameter section 34, whereby the rotary probe 42 is held in a position a as indicated in FIG. 4. When the under thread has been consumed so that the larger diameter section 34 has no layers of thread on it, the rotary probe 42 is allowed to move axially to a position b by the action of the spring 54 through the guide slots 40. This causes the axially movable probe 45 and hence its projecting probe 50 to retract from the forward to rearward positions.
The axial displacement of the probe 50 is detected by means of a proximity sensor which will be described later in detail. Since the axial displacement is detected when the thread has been consumed to leave no thread on the larger diameter section 34, the sewing operation is still allowed to continue with the thread remaining on the smaller diameter section 32.
The under thread is conventionally drawn up through a hole provided in the bobbin case at a position near its front end, so that if sewing operation continues after consumption of the thread on the larger diameter section, the remaining thread on the smaller diameter section will be drawn up at an angle inclined toward the larger diameter section. The gradually varying diameter section 33 provides a smooth surface for the drawn up thread, thus avoiding a damage on the under thread. The rounded surface of the projecting probe 50 has the effect of allowing the upper or needle thread to pass smoothly around the front surface of the bobbin case when both upper and under threads are drawn up by the action of the thread take-up lever (not shown).
FIGS. 5A to 5C illustrate a modification of the previous embodiment. In this modified embodiment, the rotary probe 42 and the bobbin 24 are combined to provide dual functions. As illustrated, the bobbin 24 comprises a flange 60 having a set of three axially extending parallel prongs 60 each being formed with a radially inwardly bent portion 64. The prongs 60 are disposed inward of the bore 66 through which the larger diameter section 34 extends. The larger diameter section 34 is formed with a set of three axially parallel guide slots 68 in which the prongs or guide followers 62 are respectively accommodated, and a groove 70 in which a ring (not shown) is inserted when the flange 60 engages the larger diameter section 34 of the cylinder 26 to prevent them from being decoupled from each other. When the under thread is wound on the bobbin cylinder 26, the movable flange 60 is held against the ring on the groove 70. As the bobbin 24 is mounted in the bobbin case 10, the axially movable member 45 is snugly fit into the bore 38 of the larger diameter section 34 for engagement with the projections 64, so that the axially movable flange 60 is urged by the spring 54 against the lateral edges of thread layers on the larger diameter section 34. When the thread on the larger diameter section 34 has been consumed, the flange 60 is caused to move to the right by the action of the spring 54, whereby the axially movable member 45 is moved to the retracted position.
The detection of axial displacement of the projecting probe 50 is achieved in a number of ways. Referring back again to FIG. 4, one way of displacement detection is illustrated in which a pair of sensor coils 72 and 74 is housed in a probe 70 adjacent to the projection 50 and forms part of an oscillator 78. In this embodiment, the projection 50 is formed of a material having a high iron loss, so that the oscillator 78 is prevented under the influence of the high loss from generating oscillation when the projection 50 is located in the normal position. When the projection 50 is moved to the right in response to the consumption of the under thread on the larger diameter section, the oscillator 78 is allowed to initiate oscillation which is rectified by a capacitor 80 and a resistor 82 to generate a DC voltage which is sensed by a comparator 84 to operate an audible means 86 when the DC voltage is higher than a reference voltage set by a voltage divider formed by resistors 88 and 90. A warning signal is thus given, indicating that the amount of under thread has been consumed to a predetermined amount.
In FIG. 6, the probe 70 comprises a light source, preferably a light-emitting diode 92 and a photosensitive element such as a photo-transistor 94 which are at an angle to the center line of the projection 50. The light beam emitted from the light-emitting diode 92 is reflected on the surface of the projection 50 when the latter is in the normal position and sensed by the phototransistor 94. When projection 50 is in the retracted position the path of the reflected beam is diverted out of the light receiving area of the photo-transistor 94 so that the output of the photo-transistor goes low. The low level signal is inverted by an inverter 96 and applied to the comparator 84 to generate a warning signal.
In FIG. 7, the projection 50 is provided with a permanent magnet 98 and the sensing probe comprises a reed switch 100 having a magnetized moving contact arm 102 and a stationary contact arm 104 which are connected to an audible means 108. By the repelling action of the magnet 98, the magnetized contact arm 102 is normally held away from contact with the arm 104. These contact arms are brought into electrical contact when projection 50 is moved to the retracted position to activate the audible means 108.
Alternatively, a microswitch 110 can also be employed as illustrated in FIG. 8. This microswitch includes a spring-loaded sensing arm 112 having a curved end portion in contact with the surface of projection 50, so that the arm 112 is moved to the right in response to the axial movement of projection 50. The sensing contact 114 is normally in a retracted position when the sensing arm 112 is in the normal leftward position and is moved to an extended position when the arm 112 moved to the right, completely a circuit for the audible means 108.
As shown in FIG. 9, the sensor 70 is mounted on a free end of an arm 116 which is pivoted at 118 and normally held in a vertical position to permit the insertion of the bobbin case 10 into the rotary hook 18 and moved to a horizontal position during operation in which the sensor 70 is brought into proximity to projection 50.
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A sewing machine having a rotary hook shaft, a bobbin case with a hollow cylindrical shaft journalled through the rotary hook shaft, and a bobbin rotatably mounted on the shaft of the bobbin case. An axially spring-biased cylindrical member is provided for unitary rotation with the bobbin and axially movable between a first position in which it is held against the lateral edges of the thread layers when the latter is present through the length of the cylinder of the bobbin and a second position in which the thread layers have reduced to a predetermined radial extent. A detector is provided to sense the axial movement of the spring-biased cylinder member from the first to second positions.
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This is a divisional of application Ser. No. 10/041,270 filed on Jan. 7, 2002, now U.S. Pat. No. 6,897,455.
FIELD OF THE INVENTION
The present invention generally relates to an apparatus and a method for repairing resist images on a semiconductor wafer and more particularly, relates to an apparatus and a method for repairing resist latent images on a semiconductor wafer in an aligner/scanner equipped with a supplemental imaging column.
BACKGROUND OF THE INVENTION
In microelectronics photolithography, photomasks are employed to replicate by exposing a pattern on a semiconductor wafer. When the microelectronics fabrication processes progressing into the sub-half-micron scales, the demand of higher performance photolithographic techniques has been increased. A recent trend in microelectronics photolithography has been the use of electromagnetic energies with extremely short wavelengths, or instance, in the UV wavelengths, in the X-rays, etc.
In microelectronics photolithography for replicating patterns, it may be necessary to repair the photomask since the mask fabrication process cannot produce defect-free masks at high yield. On binary intensity masks (BIM), there are two types of repair, i.e. filling pinhole defects shown in FIGS. 1A and 1B , and removing opaque defects shown in FIGS. 2A and 2B .
More recently, the technique of phase-shifting mask has been developed to improve the resolution of optical imaging systems. FIGS. 3A , 3 B and 3 C illustrate problems and results in repairing phase-shifting masks (PSM), wherein phase errors in critical areas have to be repaired in addition to the intensity defects. It is difficult to add or to remove phase shifting materials precisely in depth or refractive index to restore the desired phase relationship.
In another recently developed photolithography technology of extreme UV (EUV) lithography, the mask repair task is even more difficult. This is shown in FIGS. 4A , 4 B and 4 C. Since the EUV masks are reflective in nature, the mask blank is coated with more than 40 pairs of interference thin film materials to make it reflective. An absorber layer is coated on top of the multi-layer to be selectively removed according to the desired pattern on the mask. Even though repair of the absorber is similar to repairing the absorber pattern in a transmissive BIM, repairing any defect on the multi-layer reflecting areas is extremely difficult. Presently, there is no known method for adding or removing all the layers to the thickness specification, let alone the difficulty of making the repair seamless.
U.S. Pat. No. 6,031,598 to Tichenor et al, discloses an EUV replication system which includes a light source means, a condenser means, a mask means, an imaging lens means, and wafer means as shown in FIG. 3 . However, Tichenor et al does not disclose any provision for repairing of the resist latent image itself.
U.S. Pat. No. 5,978,441 to Early, discloses an EUV mask making method by depositing multiple layers on the mask blanket. However, Early does not disclose any method for repairing a mask substrate.
U.S. Pat. No. 5,935,737 to Yan, discloses an EUV mask repair on a mask substrate but not on the resist latent image.
It is therefore an object of the present invention to provide a method for repairing resist latent image on a wafer that does not have the drawbacks or shortcomings of the conventional method .
It is another object of the present invention to provide a method for repairing resist latent image on a wafer in an image scanner that is equipped with a primary imaging column and a supplemental imaging column.
It is a further object of the present invention to provide a method for repairing resist latent image on a wafer wherein the exposure on a first wafer and the repair on a second wafer can be conducted simultaneously in the same vacuum chamber.
It is another further object of the present invention to provide a method for repairing resist latent image on a wafer by utilizing a primary imaging column of EUV imaging optics and a supplemental imaging column of E-beam imaging optics that operate in the same vacuum chamber.
It is still another object of the present invention to provide a method for repairing resist latent image by irradiating an energy beam on a resist defect wherein the energy beam may be an E-beam, an ion-beam or an optical beam.
It is yet another object of the present invention to provide an apparatus for repairing a resist latent image on a wafer which incorporates a primary imaging column and a secondary imaging column.
It is still another further object of the present invention to provide an apparatus for repairing a resist latent image on a wafer which incorporates a primary imaging column and a secondary imaging column that operates in the same vacuum chamber.
It is yet another further object of the present invention to provide an apparatus for repairing a resist latent image on a wafer incorporating a first wafer chucking means and a second wafer chucking means capable of moving the wafer in an X-Y direction.
SUMMARY OF THE INVENTION
In accordance with the present invention, an apparatus and a method for repairing resist latent image on a wafer are provided.
In a preferred embodiment, a method for repairing resist latent image on a wafer can be carried out by the operating steps of providing an image scanner equipped with a first and a second wafer carrier; positioning a wafer on the first wafer carrier situated under a primary imaging column; imaging a resist latent image on the wafer after measuring alignment and focus on the wafer; storing a predetermined defect location in a process controller; moving the wafer positioned on the first wafer carrier under a supplemental imaging column; and irradiating an energy beam on the defect and repairing the resist latent image in a supplemental exposure step.
The method for repairing resist latent image on a wafer may further include the step of moving the second wafer carrier with the wafer on top; irradiate with the energy beam at the preferred location, or the step of monitoring the position of the second wafer carrier by the process controller and laser interferometers.
The method may further include the step of shaping the energy beam to facilitate defect repair. The method may further include the step of irradiating an electron beam on the defect, or the step of irradiating an electron beam and shaping the beam to adjust the size of the beam for said defect, or the step of selecting the energy beam from the group consisting of UV light, X-ray, electron beam and ion-beam. The method may further include the step of irradiating the energy beam of UV light that has a wavelength between about 0.1 nm and about 450 nm. The image scanner may further include an extreme UV imaging column and an E-beam imaging column situated in the same vacuum chamber. The method may further include the step of irradiating the energy beam from a source selected from the group consisting of an E-beam imaging column, an ion-beam imaging column and an optical beam imaging column.
The present invention is further directed to an apparatus for repairing a resist latent image on a wafer that incorporates a primary imaging column and a secondary imaging column which includes a vacuum chamber; a first wafer chucking means capable of moving in an x-y direction for holding a wafer thereon; a primary imaging column situated in the vacuum chamber for imaging a mask pattern on the wafer; a second wafer chucking means for moving the wafer in an x-y direction; and a second imaging column situated in the vacuum chamber for irradiating an energy beam on a defect on the wafer and repairing the mask pattern.
The apparatus for repairing a resist latent image on a wafer may further include a process controller for storing a predetermined defect location in the mask pattern on the wafer. Both wafer chucking means may further include laser interferometers for monitoring its position. The secondary imaging column may be adapted for shaping an energy beam to facilitate defect repair, or the secondary imaging column may be selected from the group consisting of an E-beam imaging column, ion-beam imaging column and optical beam imaging column. The energy beam irradiated may be selected from the group consisting of UV light, X-ray, electron beam and ion-beam. The primary imaging column may be an extreme UV imaging column and the secondary imaging column may be an E-beam imaging column. The primary imaging column may further include an energy source means, a condenser means, a mask means and an imaging lens means. The primary imaging column may further include UV light source means which has a wavelength range between about 0.1 nm and about 450 nm. The primary imaging column may be selected from the group consisting of an E-beam imaging column, an ion-beam imaging column and an optical beam imaging column. The secondary imaging column may further include a spot shaping means, a sizing means and an imaging means.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will become apparent from the following detailed description and the appended drawings in which:
FIGS. 1A and 1B are graphs illustrating a conventional method for filling pinhole defects on a binary intensity mask.
FIGS. 2A and 2B are graphs illustrating a conventional method for removing opaque defects on a binary intensity mask.
FIGS. 3A , 3 B and 3 C are graphs illustrating a conventional method and result for repairing a phase shifting mask.
FIGS. 4A , 4 B and 4 C are graphs illustrating a conventional method and result for repairing an extreme UV mask.
FIG. 5 is a schematic illustrating the present invention apparatus consisting of a primary imaging column and a secondary imaging column.
FIG. 6 is a detailed, cross-sectional view illustrating the optical arrangement in the present invention apparatus relevant to EUV imaging.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention discloses a method for repairing resist latent image on a wafer by utilizing a primary imaging column and a secondary imaging column positioned in the same vacuum chamber, wherein the primary imaging column is used to image a resist latent image on a wafer, while the secondary imaging column is used to irradiate an energy beam on a defect on the wafer for repairing the resist latent image.
The present invention further discloses an apparatus for repairing a resist latent image on a wafer that incorporates a primary imaging column and a secondary imaging column together with a first wafer chucking means and a second wafer chucking means. The primary imaging column functions to image a mask pattern on the wafer, while the second imaging column irradiates an energy beam on a defect on the wafer to repair the mask pattern.
The invention provides a solution for the mask repair problem in difficult cases of mask repair. Instead of repairing the defect at the mask, the defect is repaired at the resist image. As long as the mask is capable of being imaged to the photoresist, the defect is reproduced in the resist either in the form of additional unwanted resist or missing resist. Before the resist is developed, the defect exhibits itself as an exposed or unexposed latent image. The unexposed resist latent image can be repaired by further exposure to radiation to create an exposed image at the missing part. On the other hand, the exposed resist latent image can sometimes be repaired by further exposure to radiation to cross-link the exposed photoresist material to render it non-developable in order to correct the defect.
The present invention provides a novel apparatus for replicating a mask image and for repairing the subsequent resist latent image. After a mask pattern is written and etched on the substrate, an inspection identifies the type, size and location of the defects and the information is kept in a memory device. All defects from missing absorber are repaired by filling the missing area with the absorber locally. Opaque defects are repaired by removing the opaque spot, wherever feasible. For example, chrome residue can be removed from quartz. However, in a phase shifting mask, if removing the chrome residue can lead to phase shifting damage, then it should not be removed. Defects on the phase shifter should not be removed either. Similarly, with EUV reflective mask, the absorber residue may be removed if the removal process does not reduce the reflectivity of the underlying file stack. Defects in the underlying film stack inevitably leads to low local exposure just as absorber residues, but cannot be repaired at the mask level.
The wafer can be locally exposed at the known locations of the leftover defects not repaired at the mask level, preferably with a spot radiation. The spot radiation is preferably a focused UV light, E-beam, ion-beam or X-ray spot. The spot is preferably adjusted in size and shape to tightly cover the area of the defect. It is preferably slightly larger than the defect to allow for tolerance in placing the focused spot.
When practicing the present invention novel method, in order to maintain the highest positioning accuracy, the wafer is preferably kept on the wafer chuck after the normal patterning exposure without rechucking. Then, the wafer on the wafer chuck is moved to the repair area to be exposed by the radiation spot. Since most mask aligners provide the normal patterning exposure are equipped with laser interferometers to monitor the position of the wafer chuck, positioning the wafers under the radiation spot is relatively easy to accomplish.
To improve the throughput, it is preferred to use mask aligners equipped with two wafer chucks as shown in FIGS. 5 and 6 . One wafer undergoes normal patterning exposure, while the other wafer is being repaired. The repair operation is preferably combined with operations normally intended for the extra wafer chuck such as measuring the wafer local flatness and the location of alignment marks. Thus, the repair time is absorbed in the time allocated for the operation of the second wafer chuck. Such operation is in parallel to wafer scan and repeat operation.
The present invention radiation spot is created by light source means, condenser means and focusing means. The light source may be a lamp, a laser, an E-beam or ion-beam source, or an X-ray generator. The same light source for the normal patterning exposure can be used, but a separate light source is preferred. This way, an E-beam source may be used to repair EUV defects, while a 193 nm source may be used to repair 13.4 nm replicated defects.
EUV patterning exposure and E-beam spot repair constitute a good combination, since the wafer is operated under vacuum in both types of radiation. One common vacuum source can be used for the patterning exposure and repair to further improve the wafer throughput.
FIG. 5 illustrates a UV repair column 30 that is added to the chamber of the UV imaging column 40 . FIG. 6 illustrates an E-beam repairing column 50 that is positioned next to an EUV imaging lens 60 in an EUV scanner or stepper 10 . The repairing column includes an illuminator means 52 , a size-controlling aperture means 54 and an image lens means 56 . The size-controlling aperture means 54 is located at the conjugate plane of the wafer plane through the imaging lens. The size is adjustable by means of movable blades to control the size of the repairing spot. A single light source can be split-off to the regular and the repairing illuminators. Alternately, two separate light sources may be used such that the wavelengths of the two imaging lens may be chosen according to their respective needs. For example, a light source of a different energy may be used to cross-link the repair spot rather than exposing it.
An E-beam repairing column may be used in conjunction with an optical imaging column. Similarly, an optical repairing column may be used with an EUV imaging lens or an E-beam imaging column.
The present invention novel apparatus and method for repairing resist latent images have therefore been amply described in the above description and in the appended drawings of FIGS. 5 and 6 .
While the present invention has been described in an illustrative manner, it should be understood that the terminology used is intended to be in a nature of words of description rather than of limitation.
Furthermore, while the present invention has been described in terms of a preferred embodiment, it is to be appreciated that those skilled in the art will readily apply these teachings to other possible variations of the inventions.
The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows.
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A method and an apparatus for repairing resist latent image on a wafer are disclosed. In the method, an image scanner equipped with a first and a second wafer carrier, and a primary imaging column and a secondary imaging column is utilized to conduct the processes of imaging a resist latent image on a first wafer and repairing a defect in a resist latent image on a second wafer positioned on a second wafer carrier simultaneously. The primary imaging column and the secondary imaging column may be situated in the same vacuum chamber to facilitate operation.
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BACKGROUND OF THE INVENTION
Many industrial reactions, particularly those that involve the hydrogenation of organic compounds, are performed in stirred tank reactors employing a slurry catalyst system. Slurry catalysts are solid-phase, finely divided powders and are carried in the liquid reaction medium. The catalytic reaction is carried out, then, by contacting a reactive gas, such as hydrogen or oxygen, with the liquid organic compound in the presence of the solid-phase catalyst. On termination of the reaction, the catalyst is removed, generally by filtration, and the reaction product is recovered.
Slurry catalyst systems are inherently problematic in a number of areas, including industrial hygiene, safety, environmental, waste production, operability, selectivity and productivity. One problem, for example, is that these catalysts often are handled manually during a typical hydrogenation operation in a stirred tank reactor. Another is that many of the catalysts, hydrogenation catalysts in particular, are pyrophoric and thereby create additional safety concerns. These problems are compounded to a certain extent in that reaction rate often is a function of the catalyst concentration and, thus, catalyst concentrations generally are kept at high levels.
Monolith catalysts have been suggested for use in industrial gas-liquid reactions, but have achieved limited success. One of the advantages of monolith catalysts over slurry catalysts is that they eliminate the handling of powdered catalysts, including catalyst charging and filtration when the reaction is complete.
The following articles and patents are representative of catalytic processes including hydrogenation of organic compounds.
Hatziantoniou, et al. in “The Segmented Two-Phase Flow Monolithic Catalyst Reactor. An Alternative for Liquid-Phase Hydrogenations,”, Ind. Eng. Chem. Fundam., Vol. 23, No.1, 82-88 (1984) discloses the liquid-phase hydrogenation of nitrobenzoic acid to aminobenzoic acid in the presence of a solid palladium monolithic catalyst. The monolithic catalyst consisted of a number of parallel plates separated from each other by corrugated planes forming a system of parallel channels having a cross sectional area of 1 mm 2 per channel. The composition of the monolith comprised a mixture of glass, silica, alumina, and minor amounts of other oxides reinforced by asbestos fibers with palladium metal incorporated into the monolith in an amount of 2.5% palladium by weight. The reactor system was operated as a simulated, isothermal batch process. Feed concentrations between 50 and 100 moles/m 3 were cycled through the reactor with less than 10% conversion per pass until the final conversion was between 50% and 98%
Hatziantoniou, et al. in “Mass Transfer and Selectivity in Liquid-Phase Hydrogenation of Nitro Compounds in a Monolithic Catalyst Reactor with Segmented Gas-Liquid Flow”, Ind. Eng. Chem. Process Des. Dev., Vol. 25, No.4, 964-970 (1986) disclose the isothermal hydrogenation of nitrobenzene and m-nitrotoluene in a monolithic catalyst impregnated with palladium. The authors report that the activity of the catalyst was high and therefore mass-transfer determined the rate. Hydrogenation was carried out at 590 and 980 kPa at temperatures of 73 and 103° C. Less than 10% conversion per pass was achieved.
U.S. Pat. No. 4,743,577 discloses metallic catalysts which are extended as thin surface layers upon a porous, sintered metal substrate for use in hydrogenation and decarbonylation reactions. In forming a monolith, a first active catalytic material, such as palladium, is extended as a thin metallic layer upon a surface of a second metal present in the form of porous, sintered substrate and the resulting catalyst used for hydrogenation, deoxygenation and other chemical reactions. The monolithic metal catalyst incorporates such catalytic materials such as palladium, nickel and rhodium, as well as platinum, copper, ruthenium, cobalt and mixtures. Support metals include titanium, zirconium, tungsten, chromium, nickel and alloys.
U.S. Pat. No. 5,063,043 discloses a process for the hydrogenation of anthraquinones using a monolithic reactor. The reactor is operated in a down-flow configuration, in which liquid is distributed to the top of the reactor, and hydrogen is drawn into the reactor by the action of gravity on the descending liquid. In the preferred implementation, in which there is no net pressure difference between the inlet and the outlet of the reactor, this mode of operation can be characterized as gravity downflow.
BRIEF SUMMARY OF THE INVENTION
This invention relates to apparatus suited for gas-liquid reactions such as those employed in the hydrogenation or the oxidation of organic compounds and to a process for effecting gas-liquid reactions. The apparatus comprises the following:
a tank having at least one inlet for introduction of liquid, at least one outlet for removal of liquid, and at least one outlet for removal of gas;
a pump having an inlet and an outlet;
a liquid motive gas ejector having at least one inlet for receiving liquid, at least one inlet for receiving a reactant gas, and at least one outlet for discharging a mixture of said liquid and said reactant gas;
a monolith catalytic reactor having an inlet and an outlet;
wherein:
the inlet of said pump is in communication with said outlet from said tank for removal of liquid and said outlet of said pump is in communication with said inlet of said liquid motive gas ejector for receiving liquid,
the outlet from said liquid motive gas ejector for discharging the resultant mixture of liquid and gaseous reactant is in communication with the inlet to said monolith catalytic reactor and the outlet of said monolith catalytic reactor is in communication with at least one inlet to said tank, and,
the outlet from the tank for removal of gas is in communication with said inlet of the liquid motive gas ejector for receiving gas.
The apparatus described herein enables one to effect a catalytic retrofit of a slurry reactor and thereby offer many of the following advantages:
an ability to eliminate slurry catalysts and thereby minimize handling, environmental and safety problems associated with slurry catalytic processes;
an ability to interchange catalytic reactors when changing to a different chemistry in the same equipment;
an ability to effect multiple (sequential or parallel) reactions by using multiple catalytic reactors arranged either in series or in parallel;
an ability to maintain a separation of the reactants and reaction products from the catalyst during heat-up and cool-down and thereby minimize by-product formation and catalyst deactivation; and,
an ability to precisely start and stop a reaction by initiating or terminating circulation of the reactor contents through the liquid motive gas ejector and monolith catalytic reactor.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a view of a stirred tank reactor retrofitted for use with a monolith catalytic reactor.
DETAILED DESCRIPTION OF THE INVENTION
Slurry processes often suffer from the problem of excessive by-product formation and catalyst fouling or deactivation. These problems are in addition to those of handling and separation in slurry catalyst operation. One explanation for byproduct formation and catalyst deactivation is that during start-up and shutdown of a process, the catalyst is in contact with the liquid phase and the reactants and/or reaction products therein for an extended period of time. Conditions during start-up and shutdown involve heat-up, cool-down, pressurization, and venting of the,stirred tank which may have an adverse effect on the product quality and catalyst activity. For example, the changing conditions, particularly during shutdown when the catalyst is in contact with the reaction product, often promote byproduct formation and catalyst deactivation. Thus, the extended contact of the catalyst with the reactants and reaction product limits the ability of the operator to control reaction conditions.
To facilitate an understanding of the retrofitted stirred tank reactor equipped with a monolith catalyst and to understand how it addresses the above problems and achieve the many advantages that can result therefrom, reference is made to FIG. 1 . FIG. 1 is a schematic of a retrofit apparatus for a stirred tank reactor employing a monolith catalytic reactor. The retrofit system 2 comprises a tank 4 , a circulation pump 6 , a liquid motive gas ejector 8 and a monolith catalytic reactor 10 .
Tank 4 , which commonly existed before the retrofit as a stirred tank slurry reactor, has a jacket 12 for effecting heating and cooling of the contents therein and an agitator 14 . Other means, e.g., external exchangers for heating and cooling and agitation of tank contents, such as are commonly encountered in industrial practice may be used in the retrofit apparatus 2 . Tank 4 is equipped with at least one liquid feed inlet, typically two or more. As shown, inlet 16 provides for introduction of liquid feed or reactant, which may consist of a liquid compound or a solution of such a compound in a suitable solvent. Inlet line 18 provides for the introduction of reaction effluent from the outlet from monolith catalytic reactor 10 . A liquid effluent which consists of reaction product, and may, depending upon conditions, contain unreacted feed, flows via outlet 20 from tank 4 to the inlet of the circulation pump 6 .
The circulation pump 6 transfers the liquid reactant to the liquid motive gas ejector 8 via circulation line 22 and liquid flow rate is controlled either through control valve 23 or circulation pump 6 . Circulation pump 6 provides the motive energy for drawing reactant gas from the headspace of tank 4 via line 24 or from makeup gas line 26 to the gas inlet of the liquid motive gas ejector. The maximum gas flow is determined by the flow rate of liquid. It may be controlled to a smaller flow by means of valve 27 .
The monolith catalytic reactor 10 itself comprises a structure having parallel channels extending along the length of the structure. The structure, commonly referred to as a monolith, may be constructed from ceramic, carbon or metal substrates, or combinations thereof. The structure may be coated with a catalytic material directly or through the use of a washcoating or carbon-coating procedure, using methods known in the art of catalyst preparation. Alternatively, catalyst particles may be placed in the channels rather than coating catalyst materials onto the surface of the channels. The monolith catalytic reactor channels may be of various shapes, e.g., circular, square, rectangular, or hexagonal. The structure may contain from 10 to 1000 cells per square inch of cross-sectional area. A monolith support filled with catalyst may have from 10 to 50 cells per square inch while monolith supports having catalyst coated on the surface may have from 200 to 1000 cells per square inch.
A wide variety of catalytically active materials may be incorporated into or onto the monolith catalytic reactor, depending upon the reaction to be carried out. Examples include precious and transition metals, Raney metals, metal oxides and sulfides, metal complexes and enzymes, and combinations or mixtures thereof, such as a palladium-nickel combination. The concentration of catalytically active compound is determined by the rates of reaction and mass transfer on and to the catalytic surface, and typically ranges from 0.5 to 10% by weight, specified either relative to the weight of the monolith or to the weight of the washcoat, if one is employed.
The reactor diameter and length are sized to provide the desired velocities and residence times in the reactor. The reactor diameter is chosen to achieve a liquid superficial velocity through the reactor of 0.05 to 1.0 meters per second, preferably 0.1 to 0.5 meters per second. These flow rates are consistent with the necessity of obtaining high rates of mass transfer. The reactor length is chosen to achieve a residence time in the reactor of 0.5 to 60 seconds, depending on the rate at which the chemical reaction proceeds. Practical considerations limit the length of the reactor to be no less than half of the diameter of the reactor, and generally no more than about 3 meters.
It has been found that that the performance of the monolith catalytic reactor component of the retrofit apparatus is enhanced by including a liquid motive gas ejector at its inlet. The liquid motive gas ejector combines the liquid with reactant gas under conditions to enhance both mixing and enhanced mass transfer in the monolith catalytic reactor. These improvements can be attained because the liquid motive gas ejector allows one to control the pressure at which the gas-liquid mixture is presented to the monolith catalytic reactor. It is desired that the inlet pressure established by the liquid motive gas ejector exceeds the liquid head in the monolith catalytic reactor. The pressure differential is expressed as pounds per square inch differential (psid). Typically a pressure differential can range from 0 to about 30 psid but preferably ranges from 0.5 to about 20 psid.
One of the advantages achieved through the retrofit apparatus is the fact that the reactants and reaction product, except for the period in which these components are in contact with the catalyst itself during the reaction phase, are kept separate from the catalyst. This is accomplished through the unique configuration of the retrofit apparatus utilizing tank 4 , and allows for enhanced catalyst activity, reduced catalyst deactivation rate and fewer byproducts. The mode of operation to attain this enhanced performance is described in the following paragraphs.
Liquid is charged to tank 4 via feed line 16 . In some situations it may be advantageous to feed the liquid into the circulation line 22 upstream or downstream of the liquid motive gas ejector or the monolith catalytic reactor. The feed generated in the tank is circulated via the circulation pump to the liquid motive gas ejector and mixed with gas. The process may be operated as a batch whereby the contents in tank 4 are conveyed from the tank, through the ejector, through the monolith catalytic reactor and then back to the tank reactor until the desired conversion is reached. Optionally, the process may be operated continuously by withdrawing a portion of the liquid through product line 28 . When the process is not operated continuously, it is usually advantageous to start liquid circulation only after all conditions required for reaction have been attained, e.g., liquid has been heated to temperature and reactant gas is raised to pressure.
Liquid is circulated via the circulation pump 6 from tank 4 and conveyed via line 22 to the inlet of the liquid motive gas ejector 8 . The gaseous component for the reaction is withdrawn from the headspace of tank 4 through suction line 24 , and is simultaneously compressed by and mixed with the high pressure liquid introduced to the liquid motive gas ejector. Generally, the volumetric flow of reactant gas is from about 5 to 200%, typically from 50 to 150% of the volume of reactant liquid. As reactant gas is consumed in the catalytic reactor, it may be supplemented with makeup gas entering through line 26 . Makeup gas may be introduced at any point in the process, such as into the headspace or liquid contents of tank 4 , into suction line 24 , or into piping downstream of the ejector.
The introduction of the liquid motive gas ejector presents a considerable advantage over operation in gravity downflow mode. In gravity downflow mode, the liquid superficial velocity is determined to a great extent by the size of the flow passages (monolith channels, or spacing between particles inside these channels). Gravity downflow operation is limited in most practical cases to monoliths having no more than 400 unobstructed channels per square inch of cross-section. Also, gravity mode is subject to flow instabilities and reversal of flow direction. The ability to generate high pressure drops through the monolith catalytic reactor and high liquid velocities allows one to attain high rates of mass transfer. It also allows operation of the monolith at any angle to the vertical, including an upflow mode or in a horizontal position; it also avoids instabilities in the process.
Because the reactor component of the retrofit apparatus is separate from the feed and reaction product maintained within tank 4 , the reaction can be conducted until a desired conversion is reached, at which time circulation through the reactor is terminated. Final reaction product is removed via line 28 . This allows one to optimize conversion with selectivity, since often higher conversions lead to greater by-product formation. Furthermore, at a given conversion, by-product formation is normally lower than in conventional stirred tank operations because the liquid is not in constant contact with the catalyst component of the reaction system, and because high rates of mass transfer can routinely be attained by the combination of the ejector and the monolith catalytic reactor.
The following examples illustrate various embodiments of the invention and in comparison with the prior art.
EXAMPLE 1
Gravity Downflow Through Monolith Structure
In this example an apparatus incorporating the elements of the invention (tank, pump, liquid motive gas ejector, and a monolithic structure having a diameter of 2 inches and a length of 24 inches, and incorporating 400 channels per square inch of cross-sectional area) was used to measure the rate of mass transfer of oxygen from the gas phase (air) to the liquid phase (an aqueous solution of sodium sulfite), using the steady-state sulfite oxidation method. The liquid motive gas ejector was used as the gas-liquid distribution device, but operated in such a way as to simulate gravity downflow conditions.
The liquid flowrate through the ejector and the monolith structure were chosen so that there was no net pressure drop through the monolith structure, i.e., the frictional pressure loss equaled the static pressure increase. This condition was attained by limiting the liquid flow, and was established at the following operating parameters: liquid flowrate, 9.1 liters per minute; gas flowrate, 10.0 liters per minute; liquid pressure at inlet to the ejector: 11 psig; net pressure drop: 0 psid.
The rate of mass transfer is described by means of the volumetric gas-liquid mass transfer coefficient, k L a. The greater the value of k L a, the greater the potential productivity of the reactor in a reactive gas-liquid environment. The coefficient k L a was measured at this condition, and found to be 1.45 seconds −1.
EXAMPLE 2
Ejector-Driven Flow Through Monolith Structure
Using the apparatus described in Example 1, flow conditions were established using the ejector as both a liquid-gas distribution device and as a gas compressor, i.e., without restricting the liquid flow. At this condition, the corresponding operating parameters were: liquid flowrate, 23.9 liters per minute; gas flowrate, 36.1 liters per minute; liquid pressure at inlet to the ejector: 65 psig; net pressure drop:˜3.3 psid The coefficient k L a was measured at this condition and found to be 5.48 seconds- −1.
Table 1 below compares the results of Examples 1 and 2.
Coefficient
Superficial
Superficial gas
Net pressure
seconds −1
liquid velocity
velocity
drop
kLa
Example 1
0.092 m/s
0.101 m/s
0 psid
1.45
Example 2
0.242 m/s
0.367 m/s
3.3 psid
5.48
Clearly, from Table 1 the gravity downflow mode of operation limits the liquid and gas superficial velocities that can be attained, and thereby limits the gas-liquid mass transfer coefficient. In ejector-driven flow mode, a net positive pressure drop can be used to increase liquid and gas superficial velocities, which yields a great benefit in the gas-liquid mass transfer coefficient. That large improvement in mass transfer is due to the net pressure driving force exerted by the liquid-motive gas ejector. The ability to achieve a positive pressure driving force allows the use of more restricted monolith catalytic reactors and monolith catalytic reactors having greater numbers of channels per square inch simultaneously with high levels of mass transfer, which then can enhance productivity.
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This invention relates to process for carrying out gas-liquid reactions such as those employed in the hydrogenation or oxidation of organic compounds. In the catalytic reaction of a liquid reactant and a gaseous reactant to form a product, the improvement which comprises: pressurizing a liquid reactant and, then, introducing the resultant pressurized liquid reactant to a liquid motive gas ejector wherein it is mixed with the gaseous reactant. The mixture is passed to and reacted in a monolith catalytic reactor. The products are removed from the monolith catalytic reactor at a reduced pressure and, then introduced to a tank. The unreacted materials in the reaction product then are recirculated back to the ejector.
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FIELD OF THE INVENTION
[0001] The present invention relates to data storage generally and, more particularly, to a method and/or apparatus for implementing a smart hybrid storage based on intelligent data access classification.
BACKGROUND OF THE INVENTION
[0002] In conventional storage arrays, data storage specifications are classified into 3 major categories including (i) mission-critical data, high performance or sensitive data, (ii) reliable data or (iii) reliable and sensitive data.
[0003] Mission-critical data, high performance or sensitive data is used in key business processes or customer applications. Such data typically has a very fast response time specification. The data is transactional data having a high input/output process (i.e., IOP) performance with optimal and/or moderate reliability.
[0004] Reliable data is classified as company confidential data. Reliable data does not have an instantaneous recovery criteria for the business to remain in operation. The redundancy of such confidential data is important as data should be available under all conditions.
[0005] Data that is both reliable and sensitive uses both a high IOP performance and a highly reliable storage technology. Conventional storage systems are challenged to effectively move data between the three categories of storage based on the dynamic input/output load specifications in a storage area network (i.e., SAN).
[0006] It would be desirable to implement a hybrid storage system that considers performance to cost impact to dynamically allocate high IOP drives efficiently based on user needs.
SUMMARY OF THE INVENTION
[0007] The present invention concerns a method for configuring resources in a storage array, comprising the steps of (a) determining if a data access is a first type or a second type, (b) if the data access is the first type, configuring the storage array as a reliable type configuration, (c) if the data access is the second type, configuring the storage array as a secure type configuration.
[0008] The objects, features and advantages of the present invention include providing smart hybrid storage that may (i) be based on intelligent data access classification, (ii) drive group or volume group creation based on classified data access criteria of a user, (iii) use vendor unique bits in a control byte of a small computer system interface command descriptor block (e.g., (SCSI CDB) for input/output classification and input/output routing, (iv) provide intelligent data access pattern learn logic to dynamically allocate a solid state device drive or a group of solid state device drives to one or more hard disk groups based on the input/output load, (v) use a control byte of a small computer system interface command descriptor block by the intelligent data access pattern learn logic to initialize a track of an input/output load increase for any particular category of drive groups and track the data flow pattern, and/or (vi) provide automatic de-allocation of drives if the input/output load or data demand has reduced for any particular disk drive groups.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which:
[0010] FIG. 1 is a block diagram illustrating a context of the present invention;
[0011] FIG. 2 is a block diagram illustrating a reliable configuration of a storage system;
[0012] FIG. 3 is a block diagram illustrating a sensitive data configuration of a storage system;
[0013] FIG. 4 is a block diagram of an input/output transaction through an input/output path virtualization layer;
[0014] FIG. 5 is a block diagram of an example of a set of vendor unique bits;
[0015] FIG. 6 is a block diagram of an input/output transaction using a solid state device as an individual drive;
[0016] FIG. 7 is a block diagram of an input/output transaction using a solid state device for a disk drive group to implement a performance boost;
[0017] FIG. 8 is a block diagram of an input/output transaction using a solid state drive for a mirror disk drive group;
[0018] FIG. 9 is a block diagram of an input/output transaction using a solid state drive for an individual disk drive and a mirror disk drive group to implement a performance boost; and
[0019] FIG. 10 is a flow diagram illustrating an example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to FIG. 1 , a block diagram of a system 100 is shown illustrating a context of the present invention. The system 100 generally comprises a block (or circuit) 102 , a network 104 , a block (or circuit) 106 and a block (or circuit) 108 . The circuits 102 to 108 may represent modules and/or blocks that may be implemented as hardware, software, a combination of hardware and software, or other implementations.
[0021] The circuit 102 may be implemented as a host. The host 102 may be implemented as one or more computers (or servers or processors) in a host/client configuration. The circuit 106 may be implemented as a number of storage devices (e.g., a drive array). The circuit 108 may be implemented as a controller (e.g., an array controller). In one example, the circuit 108 may be a redundant array of independent disks (e.g., RAID) controller. The circuit 108 may include a block (or module, or circuit) 109 . The block 109 may be implemented as firmware (or software or program instructions or code) that may control the controller 108 .
[0022] The host 102 may have an input/output 110 that may present a signal (e.g., REQ). A configuration file 130 may be sent via the signal REQ through the network 104 to an input/output 112 of the controller 108 . The controller 108 may have an input/output 114 that may present a signal (e.g., CTR) to an input/output 116 of the storage array 106 .
[0023] The array 106 may have a number of storage devices (e.g., drives or volumes) 120 a - 120 n , a number of storage devices (e.g., drives or volumes) 122 a - 122 n and a number of storage devices (e.g., drives or volumes) 124 a - 124 n . In an example, each of the storage devices 120 a - 120 n , 122 a - 122 n , and 124 a - 124 n may be implemented as a single drive, multiple drives, and/or one or more drive enclosures. The storage devices 120 a - 120 n , 122 a - 122 n and/or 124 a - 124 n may be implemented as one or more hard disc drives (e.g., HDDs), one or more solid state devices (e.g., SSDs) or a combination of HDDs and SSDs.
[0024] The system 100 may implement a data access classification scheme to determine whether a particular data access should use high performance processing, high reliability storage and/or a mix of both. The system 100 may efficiently allocate data storage in the array 106 using the controller 108 . A number of bytes (e.g., SCSI CDB bytes) may be modified to detect a data class and/or allocate high reliability storage (e.g., solid state device storage versus hard disk drive storage) on the fly (e.g., without rebooting the controller 108 ).
[0025] The system 100 may process data using high performance processing and/or high reliability storage by dynamically determining an active data block access and/or a pattern received from the host 102 . The controller firmware 109 may implement an intelligent data pattern learn logic engine with smart data access classification. One or more of the solid state device drives (e.g., the drives 120 a - 120 n ) may be attached to the controller 108 to form volumes, groups or disks based on a number of implementation options. The system 100 may provide a hybrid storage system with a combination of hard disk drives 122 a - 122 n and/or solid state drives 120 a - 120 n to dynamically enhance the performance of the storage subsystem based on the input/output loads.
[0026] The system 100 may further provide an option to create and/or allocate storage based on storage criteria and/or data access classification (e.g., high sensitive data versus high reliable storage). Data that uses both reliable storage and high performance processing may be implemented dynamically by attaching one or more of the solid state drives 120 a - 120 n to the array 106 . An intelligent data access learning module may be implemented in the controller firmware 109 to monitor the data accesses and the active data blocks per unit time. The process of attaching and de-attaching the solid state drives 120 a - 120 n may be based on the controller 108 (i) mapping the active data blocks accessed and the solid state drives 120 a - 120 n and (ii) modifying the small computer system interface (e.g., SCSI) command descriptor block (e.g., CDB). The writes may be directed to the hard disk drives 122 a - 122 n and the reads may be performed via the solid state drives 120 a - 120 n . The drives 122 a - 122 n and the drives 120 a - 120 n may be asynchronously accessed.
[0027] The modes of operation of the system 100 and a flow may be described as follows. A user is generally provided an option to select a drive group or volume group based on data access classification such as (i) the data that uses reliable storage and high redundancy, (ii) the data that uses storage which may be sensitive and transactional (e.g., the storage may be implemented with fast drives and high input/output processes) and/or (iii) the data that uses high input/output processes and reliable storage with high redundancy. An administrator (or operator or technician) may create storage pools/volumes in the array 106 based on the data classification specifications of the user. The classifications during volume creation by a storage manager (or operator or technician) may be reliable storage or sensitive data storage.
[0028] Referring to FIG. 2 , a block diagram of a configuration 200 is shown illustrating a reliable data storage system. In an example implementation, the reliable storage may implement a RAID 51 or RAID 61 configuration. Other RAID configurations may be implemented to meet the criteria of a particular application. The system 200 is shown generally implementing a storage area 202 and a storage area 204 . The storage areas 202 and 204 may be operated in a RAID 1 configuration. Since the configuration 200 is targeted to reliable storage, the storage area 202 may be implemented as one or more hard disk drives 210 a - 210 n . Similarly, the storage area 204 may be implemented as a number of hard disk drives 212 a - 212 n . The drives 210 a - 210 n may be operated as in a RAID 5 configuration. The drives 211 a - 211 n may also be operated as in the RAID 5 configuration.
[0029] Referring to FIG. 3 , a block diagram of a configuration 300 is shown illustrating a sensitive data storage system. In an example implementation, sensitive data storage may implement RAID 50 or RAID 60. Other RAID configurations may be implemented to meet the criteria of a particular application. Since the configuration 300 is directed to sensitive data storage, a storage area 302 may be implemented as a number of storage devices 320 a - 320 n and a number of storage devices 322 a - 322 n . The drives 320 a - 320 n may be operated in a RAID 5 configuration. The drives 322 a - 322 n may also be operated in a RAID 5 configuration. A group of drives that incorporates the drives 320 a - 320 n may be operated in a RAID 0 configuration with another group of drives that incorporates the drives 322 a - 322 n . Input/output requests from an initiating device (e.g., the host 102 via the signal REQ) may be received at the controller 108 . A data path virtualization layer (to be described in more detail in connection with FIG. 4 ) may manage input/output requests from the host 102 to the drive groups (or volume groups) 302 .
[0030] Referring to FIG. 4 , a block diagram of an input/output transaction path 400 through a virtualization layer is shown. The path 400 generally comprises a block (or circuit) 402 , a block (or circuit) 404 , a block (or circuit) 406 , a block (or circuit) 408 , a block (or circuit) 410 , a block (or circuit) 412 , a block (or circuit) 414 , a block (or circuit) 416 and a block (or circuit) 418 . The circuits 402 to 418 may represent modules and/or blocks that may be implemented as hardware, software, a combination of hardware and software, or other implementations.
[0031] The circuit 402 may be implemented as an input/output (e.g., IO) network circuit. The circuit 404 may be implemented as an input/output processor circuit. The circuit 406 may be implemented as a data path virtualization circuit. The circuit 408 may be implemented as a virtual logical-unit-number (e.g., LUN) to logical-unit-number map manager circuit. The circuit 410 may be implemented as a controller firmware interface layer. The circuit 412 may be implemented as a router circuit. The circuit 414 may be implemented as a command circuit. The circuit 416 may be implemented as a volume creation manager circuit. The circuit 418 may be implemented as a disk drive group circuit.
[0032] The data path virtualization layer circuit 406 may receive SCSI input/output processes from the initiators (e.g., the host 102 ) and update the input/output processes with vendor unique bit information (to be described further in FIG. 5 ). The vendor unique bit information may be encapsulated by the circuit 406 as part of data frames or packets received from the initiators. The circuit 406 may update the SCSI input/output processes with the vendor unique bits in a block of data (e.g., CONTROL BYTES) of the input/output processes based on the data access criteria. In some embodiments, the vendor unique bit information may be stored in a SCSI command descriptor block before being presented to the router 412 located in the firmware 109 . Next, the vendor unique bit information may be presented to drive or volume groups (e.g., blocks 120 a - 120 n , 122 a - 122 n and 124 a - 124 n ). All of the vendor unique bits may be set to “zero” (or a logical low) to indicated input/output to data reliable only drive groups or volume groups (e.g., drives 210 a - 210 n and 212 a - 212 n ). All of the vendor unique bits may set to “one” (or a logical high) to indicate input/output to data sensitive only drive groups or volume groups (e.g., drives 320 a - 320 n and 322 a - 322 n ). The vendor unique bits may be set to a combination of zeros and ones (e.g., 01 or 10) to indicate input/output access to data reliable and data sensitive drive groups or volume groups (e.g., blocks 120 a - 120 n , 122 a - 122 n and 124 a - 124 n ). The vendor unique bits may be dynamically set based on the pattern learn logic and/or the input/output bandwidth or load.
[0033] Referring to FIG. 5 , a block diagram of an example of a set of vendor unique bits in the CONTROL BYTE of a SCSI command descriptor block is shown. The CONTROL BYTE generally comprises multi-bit (e.g., 2 bit) vendor field, a flag field and a link field. Unused bits within the CONTROL BYTE may be considered as reserved. The vendor field may occupy the upper most significant bits (e.g., bits 7 and 6 in the example) of the CONTROL BYTE. The link field may occupy the least significant bit (e.g., bit 0 ). The flag field may occupy the second to least significant bit (e.g., bit 1 ). Other arrangements of the fields may be implemented to meet the criteria of a particular application.
[0034] A data pattern learn logic engine (to be described in more detail in connection with FIG. 10 ) with data access classification may be implemented in the firmware 109 . The logic engine may study the input/output patterns received based on the control byte classification. The logic engine may start monitoring a condition for faster input/output access. Pools of solid state drives 120 a - 120 n may be kept as a global reserved cache drive group or drive pool. The learn logic normally studies why a particular category of drives (or drive groups) may be in a condition suitable for a targeted performance improvement. The learn logic may determine (i) the improvement suitable for a drive group/volume group as a whole and/or (ii) an improvement suitable for any particular drives in a drive group/volume group. The learn logic allocates a solid state drive or a set of the solid state drives 120 a - 120 n to be mapped to the existing disk drive groups.
[0035] Referring to FIG. 6 , a block diagram of a configuration 600 illustrating input/output transactions is shown. The configuration 600 may have a storage area 602 , a storage area 604 , and a storage area 606 . The storage area 606 may be implemented as one or more solid state drives 620 a - 620 n . The solid state drives 620 a - 620 n may be implemented for individual disk drives for a performance boost. The solid state drives 620 a - 620 n may act as another layer of cache for any particular drive (or drive group) during an input/output access. Data sent to the circuit 406 may be assigned the vendor unique bits. The command descriptor block may be updated for future input/output routing and tracking. The solid state drives 620 a - 620 n may further boost performance of the system 100 . The study of the input/output patterns may be continued by the intelligent data pattern learn logic. The study of the input/output patterns may be based on the control byte classification. If the logic determines that the input/output load or the input/output hit to any drive groups categorized for data reliability and data sensitivity is reduced, the logic may de-allocate the mapped solid state device region from the corresponding drive group. The de-allocation region may be reallocated at a later time.
[0036] Referring to FIG. 7 , a block diagram of an input/output transaction using solid state devices for disk drive groups to implement a performance boost is shown. A configuration 700 for the transaction may comprise a storage area group 702 and a storage area group 704 . The group 702 and the group 704 may be arranged in a RAID 1 configuration for reliability purposes. Internally, each group 702 and 704 may be arranged in a RAID 5 configuration. Multiple solid state drives 720 a - 720 c may be implemented to boost a performance of the drives 710 a - 710 c in the group 702 . A number of the drives 720 a - 720 c may match a number the drives 710 a - 710 c to maintain the same storage capacity. However, the drives 720 a - 720 c may not have the direct one-to-one relationships with the drives 712 a - 712 c , as illustrated in FIG. 6 . In some embodiments, additional solid state drives may be implemented to boost a performance of the drives 712 a - 712 c in the group 704 . Other configurations may be implemented to meet the criteria of a particular application.
[0037] Referring to FIG. 8 , a block diagram of an input/output transaction using solid state drives for mirrored disk drive groups as a whole to implement a performance boost is shown. A configuration 800 for the transaction may comprise a storage area group 802 . The storage area group 802 may implement a RAID 0 configuration for sensitive data storage. The drives 810 a - 810 c may be arranged in a RAID 5 configuration. The drives 812 a - 812 c may be arranged in another RAID 5 configuration. Multiple solid state drives 820 a - 820 c may be implemented to boost a performance of the drives 810 a - 810 c and 812 a - 812 c in the group 802 . The drives 820 a - 820 c may have a one-to-many relationship with the drives 810 a - 810 c and 812 a - 812 c . Other configurations may be implemented to meet the criteria of a particular application.
[0038] Referring to FIG. 9 , a block diagram of an input/output transaction using solid state drives for individual disk drives and mirrored disk drive group as a whole to implement a performance boost is shown. A configuration 900 for the transaction may comprise a storage area group 902 . The storage area group 902 may implement a RAID 0 configuration for sensitive data storage. The group 902 may comprise multiple drives 910 a - 910 c and multiple drives 912 a - 912 c . The drives 910 a - 910 c may be arranged in a RAID 5 configuration. The drives 912 a - 912 c may be arranged in another RAID 5 configuration. One or more solid state drives 920 a - 920 c may be implemented to boost a performance of the group 902 . The drives 920 a - 920 c may have a one-to-one relationship with a subset of the drives within the group 902 . For example, the drive 920 a may be coupled to the drive 910 a . The drive 920 b may be coupled to the drive 910 c . Furthermore, the drive 920 c may be coupled to the drive 912 c . Other configurations may be implemented to meet the criteria of a particular application.
[0039] Referring to FIG. 10 , a method (or process) 1000 is shown illustrating how a data access classification is made. The method 1000 also shows how the solid state drives 120 a - 120 n may be allocated to existing disk groups based on a number of learn cycles. The method 1000 generally comprises a step (or state) 1002 , a step (or state) 1004 , a decision step (or state) 1006 , a step (or state) 1008 , a step (or state) 1010 , a step (or state) 1012 , a decision step (or state) 1014 , a step (or state) 1016 , a step (or state) 1018 , a step (or state) 1020 , a step (or state) 1022 and a step (or state) 1024 .
[0040] The state 1002 may be implemented as a start state. The state 1004 may be implemented to allow an administrator (or operator or technician) to create storage based on a data classification. For example, the storage may be created based on sensitive data versus reliable data. Next, the decision state 1006 generally determines if the data is reliable/sensitive. If the data is sensitive, the method 1000 generally moves to the state 1008 . The state 1008 may configure the storage as a RAID 50 or RAID 60 storage device. Next, the method 1000 may move to the state 1010 . If the state 1006 determines that the data is intended to be reliable data, the method 1000 generally moves to the state 1012 . In the state 1012 , the method 1000 may configure the storage array as a RAID 51 or RAID 61 storage device and the method 1000 may move to the state 1010 . The state 1010 may analyze a data pattern and generates a mapping table between the volume group and the active blocks. Next, the method 1000 may move to the decision state 1014 . The decision state 1014 generally determines if an active block may benefit from a performance boost. If an active block may benefit from the performance boost and the data is sensitive data, the state 1016 generally attaches a solid state device the RAID 50/RAID 60 storage. If active block may benefit from the performance boost and the data is reliable data, the method 1000 may attache a solid state device to the RAID 51/RAID 61 storage in the state 1020 . If the active block may not benefit from a performance boost, the method 1000 may move to the state 1018 . In the state 1018 , a data access module generally decides whether removal of one or more of the solid state devices may be appropriate based on a learn cycle. Next, the state 1022 frees up the solid state device identified in the state 1020 . Next, the state 1024 ends the process.
[0041] Implementation of a neural network may provide a possibility of learning. Given a specific task to solve and a class of functions, the learning may involve using a set of observations to find functions and/or relations that solves the tasks in an optimal sense. A machine learning method may involve a scientific discipline concerned with the design and development of techniques that may allow computers to evolve behaviors based on empirical data, such as from sensor data or databases. Artificial neural networks may comprise mathematical models or computational models inspired by structural and/or functional aspects of biological neural network. Cluster analysis (or clustering) may be the assignment of a set of observations into subsets (call clusters) so that observations in a same cluster may be similar in some sense. Clustering may be a technique (or method) of unsupervised learning and a common technique for statistical data analysis.
[0042] In some embodiments, the smart data access classification may be based on artificial intelligence. An artificial intelligence based smart data classification module generally performs the data pattern analysis based on an artificial neural network computation module. The artificial neural network computation model generally forms a cluster for data utilizing the sensitive/reliable storage over a learning time (e.g. T learn ). The computation model may classify the volume group/disk/active blocks under the categories. Some artificial neural networks, such as a self-organizing map (e.g., SOM) network, may be used to cluster the data automatically. Thereafter, the high-performance data may be viewed as one of the clusters.
[0043] The data pattern analysis may be a three-dimensional computation where the learning is done based on the following criteria:
[0044] 1) Analyzing the input/output data coming to a volume group in the storage subsystem behind the controller 108 .
[0045] 2) A next level of data pattern analysis may be performed based on the input/output transfers reaching the target physical drives and the blocks that are active during the input/output transfer.
[0046] 3) A table may be built during the learning cycle with the column group versus the drive versus the active blocks.
[0047] 4) Based on the high activity blocks that may be available, clusters may be created for (i) high input/output processes for sensitive blocks and (ii) average input/output processes for reliable blocks using unsupervised cluster analysis method.
[0048] 5) The learning cycle may be dynamic and self-defined based on the patterns and a consistency of the patterns to derive a relationship between the active blocks and the input/output transfers.
[0049] An example of multiple (e.g., N) learning cycles per multiple (e.g., three) active volume groups is generally illustrated in Table I as follows:
[0000]
TABLE I
Learning Cycle
T1
T2
T3
T4
T5
. . .
Tn
Volume
Volume
Ac-
Group
Group 1
tive
Volume
Group 2
Volume
Ac-
Ac-
Ac-
Ac-
Ac-
Ac-
Group 3
tive
tive
tive
tive
tive
tive
[0050] An example of the multiple learning cycles per physical drive (e.g., PD) is generally illustrated in Table II as follows:
[0000]
TABLE II
Learning Cycle
T1
T2
T3
T4
T5
. . .
Tn
Volume
Volume
PD1, PD2,
Group
Group 1
PD3
Volume
Group 2
Volume
PD13
PD12
PD12,
PD11,
PD11,
PD11,
Group 3
PD13
PD12
PD12
PD12
[0051] An example of the learning cycles per active blocks (e.g., B) is generally illustrated in Table III as follows:
[0000] TABLE III Learning Cycle T1 T2 T3 T4 T5 . . . Tn Volume Volume B1, B11, Group Group 1 B23 Volume Group 2 Volume B23, B23, B23, B27 B27 B27 Group 3 B27 B27 B27
As per the tables, the data classification module generally identifies the blocks utilizing the high input/output process storage. The data classification module may also decide among the blocks based on the active volume groups, the physical drives and the active blocks.
[0052] The system 100 may implement a user option to select multiple (e.g., three) different levels of data storage access. The different levels may include, but are not limited to, (i) sensitive data storage, (ii) reliable data storage and (iii) reliable and sensitive data storage. The system 100 may allocate and/or de-allocating a number of solid state drives 120 a - 120 n to act as temporary cache layers to a disk drive group/volume group by a learn logic engine based on input/output load requirements. The system 100 may provide (i) easy and efficient storage planning based on data access criteria of the user, (ii) better reliability, (iii) dynamic performance boost and/or (iv) a cost versus performance advantage. Usage of hybrid drives with NAND flash memory integrated for disk caching may further boost the performance. The system 100 may be implemented for (i) web service and Internet service providers (e.g., ISPs), (ii) database applications, (iii) military applications, (iv) high performance computing applications and/or (v) image processing applications.
[0053] The functions performed by the diagram of FIG. 10 may be implemented using one or more of a conventional general purpose processor, digital computer, microprocessor, microcontroller, RISC (reduced instruction set computer) processor, CISC (complex instruction set computer) processor, SIND (single instruction multiple data) processor, signal processor, central processing unit (CPU), arithmetic logic unit (ALU), video digital signal processor (VDSP) and/or similar computational machines, programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software, firmware, coding, routines, instructions, opcodes, microcode, and/or program modules may readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). The software is generally executed from a medium or several media by one or more of the processors of the machine implementation.
[0054] The present invention may also be implemented by the preparation of ASICs (application specific integrated circuits), Platform ASICs, FPGAs (field programmable gate arrays), PLDs (programmable logic devices), CPLDs (complex programmable logic device), sea-of-gates, RFICs (radio frequency integrated circuits), ASSPs (application specific standard products), one or more monolithic integrated circuits, one or more chips or die arranged as flip-chip modules and/or multi-chip modules or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s).
[0055] The present invention thus may also include a computer product which may be a storage medium or media and/or a transmission medium or media including instructions which may be used to program a machine to perform one or more processes or methods in accordance with the present invention. Execution of instructions contained in the computer product by the machine, along with operations of surrounding circuitry, may transform input data into one or more files on the storage medium and/or one or more output signals representative of a physical object or substance, such as an audio and/or visual depiction. The storage medium may include, but is not limited to, any type of disk including floppy disk, hard drive, magnetic disk, optical disk, CD-ROM, DVD and magneto-optical disks and circuits such as ROMs (read-only memories), RAMS (random access memories), EPROMs (electronically programmable ROMs), EEPROMs (electronically erasable ROMs), UVPROM (ultra-violet erasable ROMs), Flash memory, magnetic cards, optical cards, and/or any type of media suitable for storing electronic instructions.
[0056] The elements of the invention may form part or all of one or more devices, units, components, systems, machines and/or apparatuses. The devices may include, but are not limited to, servers, workstations, storage array controllers, storage systems, personal computers, laptop computers, notebook computers, palm computers, personal digital assistants, portable electronic devices, battery powered devices, set-top boxes, encoders, decoders, transcoders, compressors, decompressors, pre-processors, post-processors, transmitters, receivers, transceivers, cipher circuits, cellular telephones, digital cameras, positioning and/or navigation systems, medical equipment, heads-up displays, wireless devices, audio recording, storage and/or playback devices, video recording, storage and/or playback devices, game platforms, peripherals and/or multi-chip modules. Those skilled in the relevant art(s) would understand that the elements of the invention may be implemented in other types of devices to meet the criteria of a particular application.
[0057] While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the scope of the invention.
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A method for configuring resources in a storage array, comprising the steps of (a) determining if a data access is a first type or a second type, (b) if the data access is the first type, configuring the storage array as a reliable type configuration, (c) if the data access is the second type, configuring the storage array as a secure type configuration.
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